UNDERSTANDING CANCER: A

COMPREHENSIVE GUIDE FOR

STUDENTS
INTRODUCTION TO CANCER
Cancer is a term used for a group of diseases characterised by the
uncontrollable growth and spread of abnormal cells in the body. Unlike
normal cells, which grow, divide, and die in an orderly way, cancer cells
continue to grow and divide without control. This uncontrolled growth can
result in the formation of lumps or masses called tumours. Some tumours are
benign, meaning they do not spread to other parts of the body and are
generally not life-threatening. Others are malignant, which can invade
surrounding tissues and spread to distant organs, a process known as
metastasis.

Globally, cancer is one of the leading causes of death, affecting millions of

people each year. It poses a major public health challenge because of its
complex nature and the variety of factors involved in its development.
Understanding cancer is important not only for medical professionals but
also for students and the general public, as early knowledge can lead to
better prevention, early detection, and treatment outcomes.

WHAT EXACTLY IS CANCER?

In our bodies, cells are the building blocks of all tissues and organs. Normally,
cell growth and division are tightly regulated processes, ensuring that new
cells are produced only when needed, such as during growth or to replace
damaged cells. Cancer occurs when these regulatory mechanisms fail,
causing cells to multiply unchecked. These abnormal cells may cluster
together to form tumours, which may disrupt the normal function of tissues
and organs.

There are two main types of tumours:

• Benign Tumours: These tumours grow slowly, remain localized, and do

not invade nearby tissues or spread to other parts of the body. Although
 they can sometimes cause problems by pressing on organs or tissues,
they are generally not dangerous and can often be removed surgically.
• Malignant Tumours: These are cancerous tumours. They grow rapidly,
invade surrounding tissues, and have the potential to spread through
the bloodstream or lymphatic system to distant organs. This ability to
spread makes malignant tumours highly dangerous and life-threatening
if not treated effectively.

SIGNIFICANCE OF CANCER IN GLOBAL HEALTH

According to global health statistics, cancer is responsible for millions of

deaths worldwide every year. It can affect individuals of any age, gender, or
ethnicity, although certain types of cancer are more common in particular
groups. Factors such as lifestyle, genetics, environment, and infections can
influence the risk of developing cancer.

Cancer’s impact extends beyond physical health; it affects patients’ emotional

well-being, their families, and healthcare systems. The cost of treatment,
long-term care, and loss of productivity places a heavy burden on societies.
Therefore, raising awareness about cancer, its causes, and preventive
measures is crucial.

WHY UNDERSTANDING CANCER MATTERS

For students, understanding the basics of cancer forms an important

foundation for further studies in biology, health sciences, and medicine. It
also encourages healthy habits and awareness from a young age, promoting
early detection and timely medical intervention. Cancer research continues to
evolve, with advances in diagnosis and treatment improving survival rates;
however, prevention and education remain key components in reducing the
global cancer burden.

In summary, cancer is a complex group of diseases marked by abnormal,

uncontrolled cell growth. Differentiating between benign and malignant
tumours helps in understanding the severity and risks involved. Recognizing
cancer’s global health impact highlights the importance of learning about its
causes, symptoms, and management. This knowledge empowers students
and communities to adopt preventive strategies and support scientific
progress toward fighting this challenging disease.
WHAT IS CANCER?
To understand cancer deeply, it helps to start with how normal cells behave in
the body. Our body is made up of billions of tiny units called cells, which are
like building blocks for tissues and organs. These cells are constantly growing,
dividing into new cells, and eventually dying in a controlled and orderly
manner. This process is vital because it allows our bodies to grow, heal
wounds, and replace old or damaged cells.

NORMAL CELL LIFE CYCLE: GROWTH, DIVISION, AND DEATH

Normally, cells follow a life cycle consisting of three main stages:

• Growth: Cells grow to their mature size and prepare to divide.

• Division (Mitosis): Cells create an exact copy of themselves, producing
two daughter cells.
• Programmed Cell Death (Apoptosis): When cells are no longer needed
or become damaged, they die in a controlled way so new cells can
replace them.

This cycle is tightly regulated by the body to maintain a balance — new cells
are made only when required, and old or faulty cells are removed. Think of it
as a well-organized factory assembly line where each step is carefully
monitored to avoid mistakes or overproduction.

HOW CANCER CELLS DIFFER: UNCONTROLLED GROWTH

Cancer happens when this regulation breaks down. Instead of following the
normal rules, cancer cells grow and divide rapidly without stopping. They
ignore signals that tell them to grow only when necessary or to self-destruct if
damaged. This unchecked growth can lead to the formation of a mass called a
tumour.

Unlike normal cells, cancer cells:

• Have lost the ability to control their growth and division.

• Evade the natural process of apoptosis, so they don’t die when they
should.
• Can invade nearby tissues, disrupting their normal function.
• Have the potential to spread to other parts of the body, a dangerous
process called metastasis.
Imagine cancer cells as rebellious workers in a factory who ignore safety
rules, keep producing defective products endlessly, and then start damaging
the factory’s infrastructure. This chaos disrupts the overall functioning of the
body.

THE ROLE OF MUTATIONS IN CANCER DEVELOPMENT

But what causes these cells to behave abnormally? The answer lies in changes
to their genetic material called mutations. DNA inside each cell acts like an
instruction manual, guiding how the cell grows, divides, and dies. Mutations
are errors or changes in this manual that can occur spontaneously or due to
factors like radiation, chemicals, infections, or inherited traits.

Some mutations damage key parts of the cell’s control system, specifically
genes that regulate growth and division. Mainly, two groups of genes are
critical:

ONCOGENES AND TUMOR SUPPRESSOR GENES

• Oncogenes: These are mutated forms of normal genes called proto-

oncogenes that usually encourage cell growth and division. When
mutated, oncogenes become overactive, pushing the cell to divide
excessively.
• Tumor Suppressor Genes: These genes act as brakes for cell growth and
division. They slow down or stop cell division and promote apoptosis
when there is DNA damage. Mutations that inactivate tumor suppressor
genes remove these “brakes,” allowing uncontrolled growth.

In cancer cells, a combination of overactive oncogenes and inactive tumor

suppressor genes disrupts normal cell cycle checkpoints. This leads to cells
multiplying rapidly and avoiding death.

FROM SINGLE ABNORMAL CELL TO TUMOR FORMATION

It usually takes multiple mutations accumulated over time for a normal cell to
transform into a cancer cell. Once a cell becomes cancerous, it grows into a
cluster called a tumour. Tumours can be:

• Benign: These remain localized and don’t invade surrounding tissues.

• Malignant: These grow aggressively, invade nearby tissues, and may
spread to different organs via blood or lymphatic vessels.
When cancer cells spread to distant locations, it complicates treatment and
reduces chances of cure. This spread, or metastasis, happens because cancer
cells develop ways to move away from their original site, enter the
bloodstream or lymph system, survive transport, and grow in new
environments.

HOW CANCER CELLS EVADE NORMAL CONTROLS

Normal cells follow many rules that prevent uncontrolled growth. Cancer
cells, however, find ways to evade these controls:

• Ignore growth signals: Cancer cells can produce their own growth
factors or keep their receptors permanently switched "on."
• Ignore anti-growth signals: Tumor suppressor genes that tell cells to
stop growing are turned off.
• Avoid apoptosis: Cancer cells disable the mechanisms that trigger
programmed cell death.
• Enable limitless division: Unlike normal cells that can divide only a
limited number of times, cancer cells activate enzymes to maintain
chromosome ends (telomeres), allowing endless replication.
• Create new blood vessels: To support their rapid growth, cancer cells
stimulate formation of new blood vessels (angiogenesis) to supply
oxygen and nutrients.

SUMMARY

In simple terms, cancer is like a group of cells that “break the rules” of normal
cell behavior—growing uncontrollably, avoiding death, invading tissues, and
moving to other parts of the body. These behaviors result from genetic
mutations affecting growth-controlling genes. This uncontrolled activity leads
to tumour formation and, if malignant, can seriously harm the body.

CAUSES OF CANCER
Cancer arises from changes in the normal functioning of cells, primarily due
to mutations in their DNA. These changes can be triggered by a diverse range
of factors which are broadly classified into external (environmental) factors
and internal (genetic) factors. Understanding these causes is essential for
prevention, early detection, and treatment.
EXTERNAL (ENVIRONMENTAL) CAUSES

Environmental factors are agents or exposures from outside the body that
increase the risk of developing cancer by causing damage to cellular DNA or
affecting normal cell processes. Some of the most significant external
carcinogens include:

• Tobacco Smoke: One of the most well-known carcinogens, tobacco

smoke contains thousands of chemicals, of which at least 70 are known
to cause cancer. Smoking is linked to various types of cancer such as
lung, mouth, throat, esophagus, bladder, pancreas, and kidney cancer.
According to the World Health Organization, tobacco smoking causes
nearly 22% of cancer deaths globally.
• Radiation: Exposure to different types of radiation can damage DNA and
lead to cancer. This includes:
◦ Ultraviolet (UV) radiation: From sunlight, UV radiation is a major
cause of skin cancers including melanoma.
◦ Ionizing radiation: Such as X-rays, gamma rays, and radioactive
materials from nuclear accidents or medical treatments, can cause
various cancers including leukemia and thyroid cancer.
• Chemicals and Carcinogens: Certain industrial chemicals, pesticides,
asbestos, benzene, and formaldehyde are linked to cancer. For example,
prolonged exposure to asbestos fibers is a leading cause of
mesothelioma, a rare lung cancer. Chemical exposure may occur in
workplaces or through contaminated food and water.
• Viruses and Bacteria: Some infectious agents can cause cancer by
altering the normal regulation of cell growth:
◦ Human papillomavirus (HPV): Causes nearly all cervical cancers
and is also linked to cancers of the mouth, throat, and anus.
◦ Hepatitis B and C viruses: Associated with liver cancer.
◦ Helicobacter pylori bacteria: A cause of stomach cancer and
certain types of lymphoma in the stomach lining.
• Lifestyle Factors: Certain habits and lifestyle choices significantly
influence cancer risk:
◦ Diet: A diet high in processed meats, red meat, saturated fats, and
low in fruits and vegetables is linked with increased risk of cancers
such as colorectal cancer.
◦ Alcohol Consumption: Excessive alcohol intake increases the risk of
cancers of the mouth, throat, esophagus, liver, and breast.
◦ Physical Inactivity and Obesity: Being overweight or inactive
increases the risk for several cancers, including breast, colon,
 kidney, and pancreatic cancer, likely due to hormonal and immune
system changes.

INTERNAL (GENETIC) CAUSES

While external factors account for a large portion of cancer cases, internal
factors also play a critical role. These include inherited genetic mutations and
other biological factors within the body that predispose individuals to cancer.

• Hereditary Factors: Some cancers run in families due to inherited

mutations that increase susceptibility. These mutations are present in all
cells from birth and can be passed from parents to children. Examples
include mutations in:
◦ BRCA1 and BRCA2 genes: Strongly associated with breast and
ovarian cancers.
◦ TP53 gene: Linked to Li-Fraumeni syndrome, which increases risk
for multiple cancer types.
Although hereditary cancers represent only about 5-10% of all cancers,
knowing family history helps in risk assessment and preventive
measures.
• Spontaneous Genetic Mutations: These mutations occur during normal
cell division due to errors in DNA replication or from reactive molecules
inside cells (oxidative stress). The accumulation of such mutations over
time can trigger cancer even without direct external exposures.
• Hormonal Changes: Hormones can sometimes stimulate the growth of
certain cancers. For example, prolonged exposure to estrogen is linked
to breast and endometrial cancer risks.

COMBINING RISK FACTORS AND THE MULTI-STEP NATURE OF

CANCER

Cancer development is rarely caused by a single factor. Usually, multiple risk

factors interact over many years to initiate and promote cancer. For example,
a person may inherit a genetic mutation that makes their cells more
vulnerable, and combined exposure to tobacco smoke and UV radiation
further increases risk.

This multi-step process involves:

• Initiation – DNA damage causes permanent mutations.

• Promotion – Mutated cells begin to grow abnormally.
• Progression – Malignant cells invade tissues and may metastasize.
SUMMARY TABLE: COMMON CAUSES AND EXAMPLES OF CANCER

Cause Category Examples Associated Cancers

Cigarette smoke, cigars, Lung, mouth, throat, bladder,

Tobacco Smoke
chewing tobacco pancreas

UV rays, X-rays, radioactive

Radiation Skin, thyroid, leukemia
materials

Asbestos, benzene, Mesothelioma, leukemia,

Chemicals
formaldehyde nasopharyngeal cancer

HPV, Hepatitis B/C,

Viruses and Bacteria Cervical, liver, stomach cancers
Helicobacter pylori

Unhealthy diet, alcohol, Colorectal, breast, liver, pancreatic

Lifestyle
obesity, inactivity cancers

Inherited Genetic Breast, ovarian, multiple cancer

BRCA1/2, TP53 mutations
Mutations types

SYMPTOMS OF CANCER
Cancer symptoms can vary widely depending on the type of cancer, its
location in the body, and the stage at which it is detected. Since cancer
originates from abnormal cell growth, symptoms typically arise due to the
tumour pressing on or invading nearby organs and tissues, or as a result of
the body’s response to cancerous changes. Recognizing these symptoms
early is crucial because it can lead to timely medical consultation, proper
diagnosis, and more effective treatment.

COMMON SYMPTOMS OF CANCER

While each type of cancer may present unique symptoms, several signs are
commonly associated with a possible cancer diagnosis. Students should be
aware of these symptoms, but also remember that many can be caused by
conditions other than cancer. Persistent or unexplained symptoms warrant
professional evaluation.

• Unexplained Weight Loss: Rapid and unintentional loss of weight

without changes in diet or exercise may indicate cancers such as
stomach, pancreatic, lung, or esophageal cancer.
 • Fatigue: Extreme tiredness that does not improve with rest can be a
symptom of cancers like leukemia or colon cancer.
• Lumps or Thickening: The appearance of a new lump or swelling,
especially in the breast, testicles, neck, or underarms, may suggest a
tumour formation.
• Skin Changes: Changes in the colour, size, or shape of moles or new
growths on the skin can be signs of skin cancer. Other skin changes
include sores that do not heal, yellowing of skin (jaundice), or darkening
patches.
• Persistent Cough or Hoarseness: Ongoing cough lasting more than a
few weeks, or changes in the voice, may be symptoms of lung or throat
cancer.
• Difficulty Swallowing or Indigestion: Problems swallowing or persistent
indigestion could indicate cancers of the esophagus, stomach, or throat.
• Unusual Bleeding or Discharge: Blood in the urine, stool, sputum, or
unusual vaginal bleeding can be early warning signs of various cancers
including bladder, colorectal, lung, or cervical cancers.
• Persistent Pain: Continuous pain, especially bone pain or headaches
that do not fade with treatment, could suggest cancer affecting bones
or the brain.

WHY SYMPTOMS VARY BY CANCER TYPE AND STAGE

The type of cancer and its anatomical location largely influence the symptoms
experienced. For example, lung cancer may cause a persistent cough and
chest pain, while colon cancer might lead to bowel habit changes and
abdominal pain. Additionally, early-stage cancers often cause few or no
symptoms because tumours may be very small or not interfering with organ
function.

As cancers grow and spread, symptoms typically become more noticeable

and severe. This progression highlights why early detection—often before
symptoms appear or when they are mild—is vital to improving prognosis.
Regular health check-ups and awareness of family history can sometimes
catch cancer early.

THE IMPORTANCE OF CONSULTING HEALTHCARE PROFESSIONALS

If any of these symptoms are persistent, worsening, or unexplained by

common illnesses, it is essential to seek medical advice promptly. Healthcare
professionals use these signs, along with clinical examinations and diagnostic
tests, to evaluate the possibility of cancer. Early consultation increases the
chances of timely diagnosis and successful treatment.

In summary, while the symptoms of cancer can vary greatly, being informed
about common warning signs empowers students and individuals to
recognize potential problems early. This knowledge is a vital part of cancer
awareness and can contribute greatly to saving lives.

TYPES OF CANCER
Cancer is not a single disease but a broad group of diseases classified
according to the type of cell or tissue where it originates. Understanding the
major types of cancer helps to comprehend how cancers differ in origin,
behavior, treatment, and prognosis. The primary types of cancer include
carcinoma, sarcoma, leukemia, lymphoma, and melanoma. Each type arises
from different tissues or cells and affects the body in unique ways.

1. CARCINOMA

Carcinomas are the most common type of cancer, accounting for about
80-90% of all cancer cases. They develop from the epithelial cells that line the
inside and outside surfaces of the body, such as skin, glands, and the lining of
organs like the lungs and intestines. Because epithelial tissues cover many
body surfaces and organs, carcinomas can occur almost anywhere.

Examples of carcinomas include:

• Lung carcinoma: Cancer arising from the epithelial cells of the lungs,
often linked to smoking. It is one of the leading causes of cancer-related
deaths worldwide.
• Breast carcinoma: Originates in the ducts or lobules of the breast tissue
and is the most common cancer among women globally.
• Colorectal carcinoma: Starts in the lining of the colon or rectum, often
developing from polyps over time.
• Prostate carcinoma: A common cancer in men, arising from the prostate
gland epithelia.

Carcinomas are further subdivided based on the type of epithelial cells

involved:

• Adenocarcinoma: Develops from glandular epithelial cells. Examples

include breast, lung, and prostate adenocarcinomas.
 • Squamous cell carcinoma: Originates from squamous epithelial cells,
commonly affecting skin, mouth, and lung.

2. SARCOMA

Sarcomas are less common than carcinomas and originate from connective
tissues such as bone, cartilage, fat, muscle, and blood vessels. These cancers
tend to occur more often in younger individuals compared to carcinomas.

Examples of sarcomas include:

• Osteosarcoma: The most common primary bone cancer, especially

affecting teenagers and young adults.
• Chondrosarcoma: Cancer of the cartilage cells, commonly seen in
adults.
• Liposarcoma: Arises from fat tissue, often occurring in the limbs or
abdomen.
• Leiomyosarcoma: Develops in smooth muscle tissue, found in organs
like the uterus, stomach, or intestines.

Sarcomas grow in the supportive or structural tissues of the body and are
often aggressive. They may cause symptoms by affecting bones or soft
tissues, leading to swelling or pain.

3. LEUKEMIA

Leukemia is a type of cancer originating from the blood-forming tissues,

especially the bone marrow. Unlike solid tumours, leukemia produces
abnormal white blood cells that multiply in the bloodstream. These abnormal
cells interfere with the production of normal blood cells, impairing immunity,
oxygen transport, and clotting.

Types of leukemia include:

• Acute lymphoblastic leukemia (ALL): Rapidly progressing cancer mostly

affecting children.
• Acute myeloid leukemia (AML): Affects myeloid cells and progresses
quickly in adults and children.
• Chronic lymphocytic leukemia (CLL): A slower-growing leukemia mostly
seen in older adults.
• Chronic myeloid leukemia (CML): Also a slower-progressing leukemia
often associated with a genetic abnormality called the Philadelphia
chromosome.
Leukemia can cause symptoms such as anemia, frequent infections, and easy
bruising due to reduced production of normal blood cells.

4. LYMPHOMA

Lymphomas are cancers that begin in the lymphatic system, a crucial part of
the immune system made up of lymph nodes, lymph vessels, and lymphoid
tissues such as the spleen and thymus. Lymphomas occur when lymphocytes,
a type of white blood cell, grow uncontrollably.

Main types of lymphoma are:

• Hodgkin lymphoma: Characterised by the presence of Reed-Sternberg

cells, it often arises in lymph nodes and has a good prognosis with
treatment.
• Non-Hodgkin lymphoma (NHL): A diverse group of lymphomas without
Reed-Sternberg cells, ranging from slow-growing to aggressive forms.

Lymphomas usually present as swollen, painless lymph nodes, fever, weight

loss, and night sweats.

5. MELANOMA

Melanoma is a cancer that arises from melanocytes, the pigment-producing

cells responsible for skin colour. Though less common than other skin
cancers, melanoma is more dangerous due to its tendency to spread rapidly.

Characteristics of melanoma include:

• Often appears as an irregular, asymmetrical mole or skin lesion with

multiple colours.
• Risk factors include excessive ultraviolet (UV) exposure from sunlight or
tanning beds.
• It can metastasize to distant organs early if not detected and treated
promptly.

Early detection of melanoma is critical because survival rates drop

significantly once it spreads beyond the skin.

COMMON CANCERS AND THEIR INCIDENCE

Cancer incidence varies worldwide and depends on genetic, environmental,

and lifestyle factors. Some of the most common cancers globally are:
 Cancer
Origin Tissue Common Examples Characteristics
Type

Majority of cancers, often

Lung, breast,
Carcinoma Epithelial cells linked to lifestyle factors like
colorectal, prostate
smoking, diet

Bone, muscle, fat, Osteosarcoma, Rare, often aggressive, found

Sarcoma
connective tissue liposarcoma in younger patients

Bone marrow
Blood cancer with abnormal
Leukemia (blood-forming ALL, AML, CLL, CML
white cells, affects immunity
cells)

Lymphatic system Hodgkin, Non- Immune system cancers, can

Lymphoma
(lymphocytes) Hodgkin lymphoma affect lymph nodes and organs

Melanocytes (skin Highly aggressive skin cancer,

Melanoma Skin melanoma
pigment cells) linked to UV exposure

SUMMARY OF DIFFERENCES BETWEEN CANCER TYPES

The following table summarises key differences between the five major types
of cancer:

Tissue of Typical Age Common

Type Examples
Origin Group Symptoms

Lumps, organ- Lung cancer, breast

Carcinoma Epithelial cells Adults, elderly specific cancer, colorectal
symptoms cancer

Swelling, pain in
Connective Children, Osteosarcoma,
Sarcoma bones or soft
tissues young adults liposarcoma
tissues

Fatigue,
Bone marrow Children,
Leukemia infections, ALL, AML
(blood cells) adults
bleeding

Swollen lymph Hodgkin lymphoma,

Lymphatic
Lymphoma All ages nodes, fever, Non-Hodgkin
system
weight loss lymphoma

Adults, Changes in
Skin Cutaneous
Melanoma especially with moles, skin
melanocytes melanoma
sun exposure lesions
PREVENTION OF CANCER
Preventing cancer is one of the most effective ways to reduce its burden on
individuals and society. While not all cancers can be prevented, many cases
can be avoided by adopting certain lifestyle changes and public health
measures. Cancer prevention involves actions that reduce exposure to risk
factors and improve the body's ability to resist cancer development.
Prevention strategies are generally divided into primary prevention and
secondary prevention.

PRIMARY PREVENTION: AVOIDING CAUSES OF CANCER

Primary prevention focuses on reducing or eliminating exposure to

substances or behaviors that cause cancer. This includes avoiding
carcinogens, modifying lifestyle habits, and protecting the body from
infections known to contribute to cancer. The most important primary
prevention measures include:

• Avoiding Tobacco Use: Tobacco smoking is the single greatest cause of

cancer worldwide, responsible for lung cancer and many other types.
Quitting smoking and avoiding secondhand smoke lowers cancer risk
drastically. Using smokeless tobacco products like chewing tobacco also
increases risk and should be avoided.
• Healthy Diet: Eating a balanced diet rich in fruits, vegetables, whole
grains, and legumes supports the immune system and helps neutralize
carcinogens. Avoiding processed meats, reducing red meat intake,
cutting down on sugary and fatty foods, and limiting salt consumption
are recommended. Diets high in antioxidants and fibre have been linked
to lower cancer rates.
• Regular Physical Activity: Exercise helps maintain a healthy weight and
supports hormonal balance, immune function, and metabolic health—
all of which reduce cancer risk. The World Health Organization
recommends at least 150 minutes of moderate-intensity aerobic
physical activity per week for adults.
• Limiting Alcohol Consumption: Excessive alcohol intake increases the
risk of several cancers, including liver, breast, mouth, and esophageal
cancers. Reducing or avoiding alcohol lowers this risk.
• Protection from Ultraviolet (UV) Radiation: UV radiation from sunlight
and tanning beds is a major cause of skin cancers such as melanoma.
Wearing protective clothing, using broad-spectrum sunscreen, avoiding
 midday sun exposure, and refraining from artificial tanning can prevent
UV-related skin damage.

VACCINATION AGAINST ONCOGENIC VIRUSES

Several infections caused by viruses increase cancer risk by disrupting normal

cell regulation. Vaccination programs are powerful preventive tools:

• Human Papillomavirus (HPV) Vaccine: HPV infections cause nearly all

cases of cervical cancer and are linked to other cancers such as those of
the anus, mouth, and throat. Vaccination before exposure to HPV
substantially reduces the risk of these cancers, and many countries
recommend vaccination for boys and girls from adolescence.
• Hepatitis B Vaccine: Chronic infection with hepatitis B virus increases
the risk of liver cancer. Vaccination against hepatitis B is highly effective
and recommended in infancy or before potential exposure.

ENVIRONMENTAL AND OCCUPATIONAL HEALTH MEASURES

Reducing exposure to environmental carcinogens is crucial in cancer

prevention. Public health policies and safety regulations help protect
populations from harmful substances:

• Minimising Exposure to Industrial Carcinogens: Workers in industries

using asbestos, benzene, formaldehyde, and other carcinogenic
chemicals should use protective equipment and follow safety protocols
to limit contact.
• Reducing Air and Water Pollution: Contaminants in air and water can
contribute to cancer risk. Governments and communities should
promote clean energy, reduce emissions, and ensure clean drinking
water.
• Safe Handling and Disposal of Chemicals: Proper disposal of hazardous
waste prevents environmental contamination and limits cancer-causing
exposures.

SECONDARY PREVENTION: SCREENING AND EARLY DETECTION

Besides preventing cancer from occurring, early detection can save lives and
improve outcomes by identifying cancer at an initial, more treatable stage.
Screening programs are an essential component of secondary prevention and
involve testing for cancer or precancerous conditions in asymptomatic
individuals at risk.

• Cervical Cancer Screening: Pap smear tests and HPV DNA testing help
detect early cervical changes before cancer develops. Regular screening
is recommended for women starting from age 21 or as advised.
• Breast Cancer Screening: Mammography can detect small breast
cancers before they cause symptoms, improving survival rates. Women
over 40 or those with risk factors should follow screening guidelines.
• Colorectal Cancer Screening: Colonoscopy and stool tests can identify
polyps or early cancers in the colon and rectum, allowing for removal or
treatment before progression.
• Lung Cancer Screening: For high-risk individuals (e.g., heavy smokers),
low-dose CT scans can detect lung cancers early.

The success of screening programs depends on public awareness,

accessibility, and regular participation.

RAISING AWARENESS AND EDUCATION

Educating the public, especially students and young adults, about cancer
causes, prevention, and early signs plays a vital role in reducing cancer
incidence and mortality. Awareness campaigns and school programs should
emphasize:

• The harmful effects of tobacco, alcohol, and unhealthy diets.

• The benefits of a healthy lifestyle and physical activity.
• The importance of vaccinations against cancer-causing viruses.
• Recognising warning signs requiring medical consultation.
• Encouraging participation in screening and regular health check-ups.

When communities understand and adopt preventive measures, the overall

burden of cancer can be significantly lowered.

SUMMARY OF CANCER PREVENTION STRATEGIES

Prevention
Measures Benefits
Type

• Avoid tobacco and alcohol Reduces cancer incidence by lowering

Primary • Healthy diet and physical exposure to carcinogens and
Prevention activity strengthening health
 Prevention
Measures Benefits
Type

• Vaccination (HPV,
Hepatitis B)
• Sun protection
• Environmental safety

• Regular screening
(cervical, breast,
Secondary Detects cancer early, improving
colorectal, lung)
Prevention treatment success and survival rates
• Early diagnosis and
treatment

• Public health campaigns

Education and Promotes healthy behaviour changes
• School programs
Awareness and informed health choices
• Community engagement

DIAGNOSIS AND TREATMENT OF CANCER

Detecting and treating cancer effectively requires a series of well-established
medical procedures. Early and accurate diagnosis, followed by suitable
treatment tailored to each patient’s specific cancer type and condition,
significantly improves the chances of successful outcomes. In this section, we
explore the most common methods used for diagnosing cancer and the
various treatment options available. We also discuss how doctors decide on
the best approach and important concepts like side effects, remission, and
palliative care.

METHODS OF CANCER DIAGNOSIS

Cancer diagnosis begins when a patient presents symptoms or when

abnormalities are found during routine screening. Confirming the presence
of cancer and determining its type, location, and stage require several
diagnostic tools:

• Biopsy: A biopsy is considered the gold standard for cancer diagnosis. It

involves removing a small sample of suspicious tissue or cells from a
tumor or affected area. The sample is then examined under a
 microscope by a pathologist to look for cancerous cells. Types of biopsy
procedures include:
◦ Needle biopsy: Using a fine or core needle to extract tissue, often
guided by imaging.
◦ Surgical biopsy: Removal of part or whole tumor tissue during
surgery.
◦ Endoscopic biopsy: Obtained through a flexible tube inserted into
internal organs such as the stomach or lungs.
Biopsies help confirm malignancy, identify cancer type, and provide
information on the cancer’s aggressiveness.
• Imaging Tests: Imaging scans allow doctors to visualize tumors inside
the body without surgery. They help in both diagnosis and staging
(finding extent of spread).
◦ X-rays: Often the first step in evaluating symptoms like persistent
cough or bone pain. They can show abnormal masses or bone
lesions.
◦ Computed Tomography (CT) Scan: Combines X-rays to create cross-
sectional images, giving detailed views of tumors and nearby
tissues.
◦ Magnetic Resonance Imaging (MRI): Uses magnetic fields and
radio waves for detailed images, especially useful for brain, spinal
cord, and soft tissue cancers.
◦ Ultrasound: Uses sound waves to detect masses in organs like liver,
breast, or thyroid.
◦ Positron Emission Tomography (PET) Scan: Shows metabolic
activity of tissues, helping detect cancer spread and monitor
treatment response.
Imaging tests are indispensable tools for mapping tumors and planning
treatment.
• Blood Tests: Although no single blood test can definitively diagnose
cancer, various blood tests support diagnosis and monitor health.
◦ Complete Blood Count (CBC): Helps detect blood cancers like
leukemia by evaluating different blood cell types.
◦ Tumor Markers: Substances produced by cancer cells or body in
response to cancer, such as PSA (prostate-specific antigen) for
prostate cancer or CA-125 for ovarian cancer, assist in diagnosis
and monitoring.
◦ Biochemical tests: Assess liver and kidney function, important
before and during treatment.
Blood tests are generally used alongside other diagnostic methods.
 • Molecular Diagnostics: Advanced techniques analyze genetic and
molecular features of cancer cells. This includes:
◦ Genetic testing: Identifies mutations driving cancer growth, such
as BRCA1/2 genes in breast cancer.
◦ Immunohistochemistry (IHC): Detects specific proteins to classify
cancer more precisely.
◦ Fluorescence in situ hybridization (FISH): Visualizes chromosomal
abnormalities.
Molecular diagnostics help select targeted therapies tailored to genetic
abnormalities.

PLANNING AND STAGING

After cancer is confirmed, the next step is staging, which determines how far
the disease has spread. Common staging systems use categories like tumor
size (T), lymph node involvement (N), and metastasis (M). This information
guides treatment decisions and helps predict prognosis.

COMMON TREATMENTS FOR CANCER

Cancer treatment is multidisciplinary and depends on several factors

including cancer type, stage, location, and the patient’s overall health. Often,
a combination of therapies is used to maximize effectiveness. The main types
of treatment are:

• Surgery: This involves physically removing the tumor and, in some

cases, nearby lymph nodes or tissues. Surgery can be curative when
cancer is localized and completely removed. It is often the first line of
treatment for solid tumors like breast, lung, or colon cancer. Surgical
techniques have advanced with minimally invasive options resulting in
quicker recovery.
• Chemotherapy: Chemotherapy uses drugs that kill rapidly dividing cells,
including cancer cells. These drugs can be administered orally,
intravenously, or by other routes. Chemotherapy treats cancers that
have spread beyond a localized area and is often combined with surgery
or radiation. However, chemotherapy also affects some healthy cells,
causing side effects like hair loss, nausea, and lowered immunity.
• Radiation Therapy: This treatment uses high-energy rays or particles to
damage DNA within cancer cells, preventing their growth and causing
cell death. Radiation is typically targeted to the tumor site to minimize
damage to normal tissues. It can be used alone or alongside surgery
and chemotherapy. Side effects include skin irritation and fatigue.
 • Immunotherapy: An emerging treatment that boosts the body’s
immune system to recognize and destroy cancer cells. Immunotherapies
include immune checkpoint inhibitors, cancer vaccines, and CAR-T cell
therapy. This approach has shown promise in cancers like melanoma,
lung cancer, and lymphoma.
• Targeted Therapy: Unlike chemotherapy, targeted therapies specifically
attack molecular changes or proteins essential for cancer growth. These
drugs block signals for cell division or survival pathways. Examples
include tyrosine kinase inhibitors and monoclonal antibodies. Targeted
treatment tends to have fewer side effects and is often used in cancers
identified by molecular diagnostics.
• Hormone Therapy: Used mainly in cancers that depend on hormones to
grow, such as breast and prostate cancers. Hormone therapies work by
blocking hormone production or preventing hormones from binding to
cancer cells, slowing the tumor’s growth.

PERSONALIZED TREATMENT PLANS

Doctors develop individualized treatment strategies based on a variety of

patient-specific factors:

• The type of cancer and its biological characteristics.

• The stage of cancer at diagnosis.
• Patient’s age, general health, and preferences.
• Presence of specific genetic mutations or markers guiding targeted
therapies.

Cancer care often involves a team of specialists including oncologists,

surgeons, radiologists, pathologists, and nurses, working together to provide
optimal treatment and follow-up.

SIDE EFFECTS OF CANCER TREATMENT

Most cancer treatments, while aimed at destroying cancer cells, can also
affect healthy tissues leading to side effects. Common side effects include:

• Fatigue and weakness

• Hair loss (mainly with chemotherapy)
• Nausea, vomiting, and loss of appetite
• Lowered immunity, increasing infection risk
• Skin changes or irritation (especially with radiation therapy)
• Organ damage depending on treatment type and dose
Managing side effects is an important part of patient care, improving quality
of life during and after treatment.

REMISSION AND PALLIATIVE CARE

Remission refers to a state where signs and symptoms of cancer decrease

significantly or disappear after treatment. Remission can be partial or
complete. Even after remission, patients require regular monitoring to detect
any recurrence early.

Palliative Care focuses on relieving symptoms and improving quality of life for
patients with advanced or incurable cancer. It addresses pain management,
psychological support, and assistance with daily activities. Palliative care can
be provided alongside curative treatments or alone when cure is not possible.

Both remission and palliative care are integral to comprehensive oncology

care, emphasizing patient well-being beyond just controlling cancer.

CONCLUSION
Throughout this guide, we have explored the complex nature of cancer,
starting from its definition as uncontrolled cell growth to the various causes,
symptoms, types, prevention strategies, and treatment options.
Understanding cancer’s biological basis helps us appreciate why early
recognition and intervention are vital for improving outcomes.

Recognizing signs and symptoms early can lead to prompt diagnosis, which
greatly influences treatment success. Awareness of risk factors, such as
tobacco use, unhealthy diets, infections, and genetic predispositions,
empowers individuals to take preventive measures and make healthier
lifestyle choices. Prevention remains the most effective way to reduce cancer
incidence and includes steps like quitting smoking, maintaining a balanced
diet, regular exercise, and vaccinations against oncogenic viruses.

Advances in medical science have significantly improved diagnostic

technologies and broadened the range of treatment options, including
targeted therapies and immunotherapies. These innovations have increased
survival rates and enhanced the quality of life for many cancer patients.
However, continued research and public support are essential to overcome
remaining challenges.
As students and young adults, adopting healthy habits and staying informed
about cancer can contribute to personal well-being and community health.
Supporting cancer awareness programs and research initiatives helps push
forward breakthroughs that will benefit future generations.

In summary, cancer is a multifaceted disease that requires a comprehensive

approach involving education, prevention, early detection, and advanced
treatment. Through knowledge and proactive action, we can reduce the
impact of cancer and move closer to more effective cures.

BIBLIOGRAPHY
The following sources were used to compile the information presented in this
document. These references consist of textbooks, scientific articles, and
reputable health organization websites, providing reliable and up-to-date
knowledge suitable for academic purposes and student understanding.

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