Introduction to Cancer

The introduction give a clear and concise overview of cancer,

focusing on its fundamental character and importance as a global
health issue.

Breakdown

1. Definition of Cancer:

o Cancer is defined as a group of diseases with shared

characteristics: uncontrolled cell growth, tissue invasion, and the
potential for metastasis (spreading to parts of the body far from
its original site).

o These characteristics distinguish cancer from normal cellular

behavior and from benign conditions.

2. Global Impact:

o\tCancer is identified as one of the leading causes of death

worldwide, underlining its prevalence and severity.

o\tThis underlines the need to study cancer in greater detail so

that better prevention, diagnosis, and treatment strategies could
be developed.

3.\tKey Features:

o\tUncontrolled Cell Growth: Cancer cells bypass normal

regulatory mechanisms, thus leading to unchecked growth and
division.

o\tInvasion: Cancer cells are capable of invading the adjacent

tissues, thus breaking their structure and function.

o\tTumor Formation:

 Benign Tumors - Non-cancerous, thus not invasive; they do

not metastasize.

 Malignant Tumors - Cancerous; they cause invasion of

neighbouring tissues and could metastasise to other organs.

Types of Cancer

This chapter classifies cancer according to the tissues or cells

from which it is derived. Each type differs in its origin, behavior,
and how it affects the body.
1.\tCarcinomas:

o\tOrigin: Epithelial cells that line organs and body surfaces.

o\tExamples: Lung, breast, and skin cancers are the most

common.

o\tRelevance: Carcinomas constitute the largest number of cancer

cases.

2.\tSarcomas:

o\tOrigin: Connective tissues such as bone, cartilage, and fat.

o Characteristics: These are rarer but often more aggressive.

o Examples: Osteosarcoma (bone cancer) and liposarcoma (fat

tissue cancer).

3. Leukemias:

o Origin: Blood-forming tissues such as bone marrow.

o Unique Feature: Unlike other cancers, leukemias do not develop

solid tumors.

o Effect: Abnormal white blood cell production disrupts normal

blood function.

4. Lymphomas:

o Origin: Lymphatic system, part of the immune system.

o Examples: Hodgkin's lymphoma and non-Hodgkin's lymphoma.

o Symptoms: Often involve swollen lymph nodes and dysfunction

of the immune system.

5. Gliomas:

o Origin: Glial cells in the brain and spinal cord.

o\tImportance: The cancers are tough to deal with because they

appear in the central nervous system and often cause neurologic
problems.

Causes of Cancer
This part discusses the different causes of cancer and how these
factors cause genetic mutation, which can lead to abnormal cell
behavior.

1. Environmental Factors:

a. Radiation: UV rays from the sun and X-rays can destroy the
DNA in the cells and cause mutations resulting in the disease. For
instance, UV rays are a common source of skin cancer.

o\tCarcinogens: For instance, tobacco smoke introduces harmful

chemicals into the body, directly increasing the risk of lung
cancer. Similarly, asbestos increases mesothelioma.

2.\tLifestyle Factors:

o\tSmoking and Alcohol Consumption: This is a lifestyle issue.

Toxic substances and carcinogens introduced by such habits
cause cancers in the lungs, liver, throat, and so on.

o\tDiet That Is Poor and Hasks Of Exercise: A diet that contains

more processed food coupled with scarce physical activity may
lead to obesity, a known risk factor for many types of cancer.

3.\tGenetic Factors:

o\tSome people inherit mutations that will increase their risk of

suffering from particular cancers. For example, mutations in the
BRCA1 and BRCA2 genes significantly increase the probability of
breast and ovarian cancers.

4.\tBiological Factors:

o\tInfections: Some viruses, such as HPV (human papillomavirus)

and Hepatitis B, can cause long-term cell damage and thus lead
to the development of cancer. HPV is strongly associated with
cervical cancer, while Hepatitis B is linked to liver cancer.

Symptoms of Cancer

This chapter discusses the general symptoms that are associated

with cancer. The following is a list of symptoms that may indicate
the presence of cancer. Here's a breakdown of each symptom:

1. Unexplained Weight Loss:

o\tUnintended and significant weight loss is one of the earliest

signs of cancers like stomach, lung, or pancreatic cancer. This is
because cancer cells require a lot of energy, and the body
responds by breaking down fat and muscle for fuel.

2.\tProtracted Fatigue or Weakness:

o\tFatigue due to cancer is not the same as ordinary tiredness. It

may persist even after rest and is caused by the body's fight
against the disease, changes in metabolism, or anemia that is
common in some cancers.

3.\tLumps or Swelling in Specific Areas:

o\tA lump or swelling that does not go away may be a sign of a

tumor. For example, lumps in the breast may be a sign of breast
cancer, while swollen lymph nodes may indicate lymphoma.

4.\tChanges in Skin Appearance:

o\tChanges in moles, new sores that do not heal, or skin

discoloration may be a sign of skin cancer or other internal
cancers that affect the health of the skin.

5.\tPersistent Cough or Difficulty Breathing:

o\tThese are commonly symptoms of lung cancer or throat cancer.

The chronic cough accompanied by blood in the sputum is highly
alarming.

Diagnosis and Detection

The following section outlines the most critical diagnosis and detection
methods, such as early identification for enhanced treatment. Here is a
summary of the key components:

1. Imaging Techniques

a. X-rays, CT scans, and MRIs are used to view internal structures to

identify tumors. For instance, an MRI can provide precision in determining
abnormalities regarding soft tissue.

2. Biopsies:

o\tThis is taking a tissue sample from a suspected tumor. A pathologist will

look at the sample under a microscope to confirm whether the tissue is
cancerous and, if so, the type and stage.

3.\tBlood Tests:

o\tSome cancers release substances called tumor markers into the blood.
For example, PSA (Prostate-Specific Antigen) is a marker for prostate
cancer. Blood tests also give clues about organ function and overall
health.

4.\tGenetic Testing:

o Recognizes mutations of certain genes such as BRCA1/BRCA2 which

predispose the individual to cancers. This will be helpful especially for
those people with a cancer history in the family so as to take preventative
measures or at least start interventions early.

Significance:

Early Detection: Cancers detected during early stages have much more
treatment alternatives and higher cure rates.

Comprehensive Analysis: Through imaging, biopsy, and genetic testing,

patients get a complete diagnosis, and with that, comprehensive
treatment planning along with risk estimation for the family.

Treatment Techniques

This chapter describes the primary techniques of cancer treatment,

explaining how each technique works and its contribution to the fight
against the disease.

1.

Surgery:

o Physically removes cancerous tumors from the body.

o Generally most effective for localized cancers that have not spread
(e.g., early-stage breast cancer).

2.

Radiation Therapy:

o Uses high-energy rays, such as X-rays or proton beams, to kill or

damage cancer cells.

o Usually used in conjunction with surgery or chemotherapy to treat

remaining cancer cells.

3.

Chemotherapy:

o Involves administering drugs that target rapidly dividing cells.

no Good for cancers that have metastasized but will also harm the body's
fast-growing healthy cells, for example, hair follicles (leading to hair loss).

4. Immunotherapy

o Boosts the immune system's ability to identify and eliminate cancer

cells

o Includes immunotherapies like immune checkpoint inhibitors that

"unblock" the immune response against the tumors

5. Targeted Therapy

o Uses drugs specifically designed to attack the molecules fueling cancer

cell growth, such as HER2 inhibitors in certain breast cancers.

o\tMinimal harm to the body cells as opposed to chemotherapeutic

agents.

Importance

•\tMultimodal Therapy: Most cures of cancer are multimodal that is two or

more treatments. For instance, removing the tumor by surgery and
treating all microscopic cancer cells by chemotherapy.

•\tTailored Treatment: With immunotherapy and targeted therapy,

advances have been made allowing for a tailored treatment to meet a
particular type of cancer and genetic makeup of a patient.

Prevention of Cancer

This chapter focuses on the prevention of cancer, although not all cancers
can be prevented. Here is a summary of its main points:

1.

Healthy Lifestyle Choices:

o Not smoking and not drinking too much alcohol minimizes exposure
to carcinogens that are directly associated with cancers, such as lung and
liver cancer.

o Maintaining a good body weight of healthy weight maintained through

diet consisting of fruits and vegetables, plus whole grains, exercised
regularly. Risk of obesity-linked cancers, breast and colon reduced.

2.\tVaccinations:
o Vaccines contribute significantly to prevent cancers that develop from
infections :

HPV Vaccine: It can prevent human papillomavirus, which strongly links

with cancer of cervix and other malignancies.

\tHepatitis B Vaccine: Prevents Hepatitis B infection, thereby reducing the

risk of liver cancer.

3.\tRegular Screenings:

o\tEarly detection tests such as mammograms for breast cancer and

colonoscopies for colorectal cancer help detect cancer at an early stage
when it is most treatable.

o\tRegular check-ups are especially important for people with a family

history of cancer or other risk factors.

Importance of Prevention:

•\tThis section emphasizes the role of preventive healthcare and lifestyle

management in decreasing the incidence of cancer.

•\tIt shows how awareness, vaccination programs, and regular screenings

improve public health and reduce mortality from cancer.