Cancer

Estimated time: 10 minutes

CISCE: Class 12

Definition: Cancer

Cancer is a disease characterised by uncontrolled and abnormal division of body cells due to loss of normal growth regulation.

CISCE: Class 12

Metastasis is the process by which cancer cells spread from the primary site to distant organs through blood or lymph.

CISCE: Class 12

Tumour is a mass of abnormally proliferating cells formed due to uncontrolled cell division.

CISCE: Class 12

Benign tumour is a non-cancerous tumour that remains confined to its original site and does not spread to other parts of the body.

CISCE: Class 12

Malignant tumour is a cancerous tumour that grows rapidly, invades surrounding tissues and spreads to distant organs.

Maharashtra State Board: Class 12

Meaning: Cancer is the abnormal, uncontrolled division of cells forming a mass called a neoplasm/tumour. Cancer cells lack contact inhibition and compete with normal cells for nutrients.
Benign Tumour: Grows slowly, stays restricted to its site of origin (localised), and does not spread. It can still be harmful (e.g., brain tumour). Examples — Adenoma, Fibroid.
Malignant Tumour: Grows rapidly, invades surrounding tissues, and spreads to other organs via blood or lymph, forming secondary tumours. This spreading process is called metastasis.
Types of Cancer: Based on tissue affected — Carcinoma, Sarcoma, Lymphoma, Leukaemia, and Adenocarcinoma.
Causes: Chemicals (e.g., nicotine), radiation (X-rays, gamma rays), viruses (oncogenic), oncogenes, and addictive substances (e.g., tobacco).
Diagnosis & Treatment: Diagnosed by biopsy. Treated by radiation therapy (X-rays/gamma rays), chemotherapy, immunotherapy, and surgery.