Overview

Oncology is the study and treatment of cancer. Cancer is not one disease but hundreds, all sharing a common feature: uncontrolled cell growth.

Core Idea

The core idea is rebellion. A cancer cell is a normal cell that has stopped following the rules. It divides when it shouldn’t, refuses to die when it should (apoptosis), and invades territories where it doesn’t belong (metastasis).

Formal Definition

A branch of medicine that deals with the prevention, diagnosis, and treatment of cancer. A medical professional who practices oncology is an oncologist.

Intuition

Cancer is evolution gone wrong inside the body. Cancer cells evolve to survive the body’s defenses and treatments. Treating it is like fighting a guerrilla war against your own cells.

Examples

  • Carcinoma: Cancer starting in the skin or tissue lining organs (e.g., lung, breast).
  • Leukemia: Cancer of the blood-forming tissues (bone marrow).
  • Chemotherapy: Using toxic drugs to kill rapidly dividing cells.
  • Radiation Therapy: Using high-energy beams to damage DNA and kill cancer cells.

Common Misconceptions

  • Misconception: We will find “The Cure” for cancer.
    • Correction: Because cancer is hundreds of different diseases with different genetic causes, there will likely be hundreds of different cures, not one magic bullet.
  • Misconception: Cancer is a modern disease.
    • Correction: It has existed as long as multicellular life, but we see more of it now because people live longer (age is the biggest risk factor).
  • Genetics: Cancer is fundamentally a genetic disease (mutations).
  • Metastasis: The spread of cancer cells to new areas of the body.
  • Palliative Care: Care focused on relief from symptoms and stress, rather than cure.

Applications

  • Screening: Pap smears, colonoscopies, and mammograms save lives by catching cancer early.
  • Precision Medicine: Sequencing a tumor’s DNA to choose the exact drug that targets its specific mutations.

Criticism and Limitations

  • Toxicity: Traditional treatments (chemo/radiation) harm healthy cells too, causing severe side effects.
  • Cost: New cancer drugs are among the most expensive medicines in the world.

Further Reading

  • The Emperor of All Maladies: A Biography of Cancer by Siddhartha Mukherjee
  • The Biology of Cancer by Robert Weinberg