Cancer & Biology

Uncontrolled cell growth, underlying mechanisms, and clinical approaches

Chapter Summary

Cancer arises when normal regulatory mechanisms that control cell division fail. Genetic mutations in oncogenes and tumor suppressors, along with environmental factors, drive uncontrolled proliferation. Clinical strategies include detection, staging, treatment, and prevention.


Definition

What Is Cancer?

Cancer is a collection of diseases characterized by uncontrolled cell growth that can invade surrounding tissues and spread (metastasize) to distant organs.

Key Molecular Pathways

  • Oncogenes: mutated proto-oncogenes that drive proliferation (e.g., Ras).
  • Tumor Suppressors: genes that inhibit division (e.g., p53, RB); loss leads to unrestrained growth.
  • Apoptosis Evasion: cancer cells disable programmed cell death pathways.

Key Terms

Quiz Yourself

1. Which gene type inhibits cell division and prevents tumor formation?




2. Which of the following is a characteristic of cancer?