Cancer — Core Principles
Core Principles
Cancer is a disease characterized by uncontrolled cell growth and division, leading to the formation of abnormal cell masses called tumors. It arises from genetic mutations in genes that regulate the cell cycle, particularly proto-oncogenes (which become oncogenes, promoting growth) and tumor suppressor genes (which normally inhibit growth).
Malignant tumors, unlike benign ones, can invade surrounding tissues and spread to distant sites through a process called metastasis, making them life-threatening. Carcinogens, including physical (radiation), chemical (tobacco), and biological (viruses) agents, are primary causes.
Early detection is crucial and involves methods like biopsy, imaging (CT, MRI), and molecular tests. Treatment strategies include surgery, radiotherapy, chemotherapy, immunotherapy, and targeted therapy, often used in combination to combat the disease effectively.
Often confused with
Side-by-side differences the NEET paper likes to test.
| Aspect | Cancer | Benign vs. Malignant Tumors |
|---|---|---|
| Growth Rate | Slow, often encapsulated | Rapid, invasive |
| Invasion of Tissues | Does not invade surrounding tissues | Invades and infiltrates surrounding tissues |
| Metastasis | Does not metastasize (spread to distant sites) | Metastasizes (spreads to distant sites via blood/lymph) |
| Cell Differentiation | Well-differentiated (resembles parent tissue) | Poorly differentiated or undifferentiated (anaplastic) |
| Recurrence after Removal | Less likely to recur | More likely to recur |
| Life Threat | Generally not life-threatening (unless vital organ compression) | Potentially life-threatening |
The distinction between benign and malignant tumors is critical in understanding cancer. Benign tumors are non-cancerous growths that are typically slow-growing, encapsulated, and do not invade surrounding tissues or metastasize.
They are generally well-differentiated, meaning their cells closely resemble normal cells, and are usually curable by surgical removal with a low chance of recurrence. In contrast, malignant tumors are cancerous, characterized by rapid, uncontrolled growth, invasion of adjacent tissues, and the ability to metastasize to distant organs.
Their cells are often poorly differentiated or anaplastic, and they pose a significant threat to life, often requiring aggressive multi-modal treatments and having a higher likelihood of recurrence.
Why it is tested: For NEET, understanding the clear differences between benign and malignant tumors is fundamental. Questions often test the characteristics of each, especially the concept of metastasis as a defining feature of malignancy. Knowledge of these differences is essential for comprehending diagnostic approaches and treatment rationales.