CANCER

Overview of Cancer

Cancer refers to a group of diseases characterized by the uncontrolled growth and spread of abnormal cells. It can occur in almost any part of the body, with over 36 types recognized globally. The most common types include lung, breast, colorectal, prostate, and stomach cancers.

Key Statistics from the WHO and IARC (2022-2024):

• Global Incidence: Approximately 20 million new cancer cases were recorded in 2022, with 9.7 million deaths.
• Most Common Cancers:
• Lung cancer: 2.5 million cases (12.4% of total).
• Breast cancer: 2.3 million cases (11.6%).
• Colorectal cancer: 1.9 million cases (9.6%).
• Cancer Mortality:
• Lung cancer remains the leading cause of cancer deaths globally (18.7%), followed by colorectal, liver, and breast cancers.

WHO Global Survey Insights:

A survey conducted across 115 countries revealed that only 39% provided basic cancer management under universal health coverage (UHC). Palliative care services, including pain relief, were covered in just 28% of the countries, highlighting disparities in cancer care.

Cancer Inequities:

• Income Disparities: High-income countries are significantly better equipped with cancer management tools, such as stem-cell transplants and radiation therapy, compared to low-income countries.
• Gender Differences:
• Women in lower-income nations face higher mortality rates due to late diagnosis and limited treatment access.
• Cervical cancer, preventable and treatable, remains prevalent in regions with limited healthcare resources.

Projections:

• By 2050, cancer cases are expected to rise by 77% (up to 35 million annually), driven by aging populations, increased exposure to risk factors (e.g., tobacco, obesity), and environmental pollutants.

WHO Initiatives:

The WHO emphasizes the need for equitable access to cancer care, pushing for investments in diagnostics, treatment, and preventive strategies. The "Cervical Cancer Elimination Initiative" is an example of efforts targeting high-impact interventions.

Detailed Overview of Different Types of Cancer

1. Carcinomas

• Definition: Cancers originating in epithelial cells that line the internal organs and skin.
• Common Examples:
• Lung Cancer: Often linked to smoking and air pollution; it is the most common cancer worldwide with 2.5 million new cases annually.
• Breast Cancer: Predominantly affects women but can occur in men; 2.3 million cases yearly, with a high survival rate if detected early.
• Colorectal Cancer: Develops in the colon or rectum; diet, lifestyle, and genetics are significant risk factors.
• Subtypes: Squamous cell carcinoma, adenocarcinoma.

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2. Sarcomas

• Definition: Cancers arising from connective tissues, including bones, muscles, fat, and cartilage.
• Common Examples:
• Osteosarcoma: Bone cancer primarily affecting children and young adults.
• Liposarcoma: Originates in fat cells, typically in the abdomen or limbs.
• Characteristics: Rare compared to carcinomas, often treated with surgery and chemotherapy.

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3. Leukemias

• Definition: Cancers of the blood-forming tissues, such as the bone marrow, leading to abnormal production of blood cells.
• Types:
• Acute Lymphoblastic Leukemia (ALL): Common in children.
• Chronic Myeloid Leukemia (CML): More frequent in adults.
• Symptoms: Fatigue, frequent infections, and easy bruising.
• Treatment: Chemotherapy, radiation, and bone marrow transplants.

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4. Lymphomas

• Definition: Cancers affecting the lymphatic system, crucial for immunity.
• Types:
• Hodgkin's Lymphoma: Characterized by the presence of Reed-Sternberg cells.
• Non-Hodgkin's Lymphoma: Includes a diverse group of cancers affecting B cells or T cells.
• Symptoms: Swollen lymph nodes, fever, and weight loss.

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5. Melanomas

• Definition: Cancers that develop in melanocytes, the pigment-producing cells of the skin.
• Characteristics:
• Highly aggressive but curable if detected early.
• Linked to UV exposure and genetic predisposition.
• Common Sites: Skin, eyes, and rarely, internal organs.

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6. Brain and Spinal Cord Cancers

• Definition: Tumors arising in the central nervous system.
• Types:
• Gliomas: Originate in glial cells.
• Medulloblastomas: Found primarily in children.
• Symptoms: Seizures, headaches, and neurological deficits.
• Prognosis: Depends on the tumor's location, type, and size.

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7. Other Common Cancers

• Prostate Cancer:
• Affects the prostate gland in men; slow growing in most cases.
• Risk increases with age.
• Liver Cancer:
• Linked to hepatitis B/C infection, alcohol use, and fatty liver disease.
• Common in regions with high hepatitis prevalence.
• Cervical Cancer:
• Often caused by the Human Papillomavirus (HPV).
• Can be prevented through vaccination and regular screening.

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Treatment Modalities

• Surgery: Removal of tumors, primarily for localized cancers.
• Radiation Therapy: High-energy beams target cancer cells.
• Chemotherapy: Uses drugs to destroy or inhibit cancer cell growth.
• Immunotherapy: Boosts the immune system to combat cancer.
• Targeted Therapy: Focuses on specific genetic markers of cancer cells.