Cancer
Cancer is not one disease but a family of more than 100 conditions in which cells grow abnormally and can spread to other parts of the body. Outcomes have improved dramatically with screening, early diagnosis, and modern treatment.
Table of Contents
Quick Facts
- ICD-10: C00–D49
- Number of types: >100
- Often preventable: 30–50% of cancers
Overview
Cancer develops when changes in genes that normally control cell growth lead to uncontrolled cell division. Cells can invade nearby tissues and spread (metastasize) through blood or lymph vessels to distant organs.
Common Cancer Types
- Breast cancer
- Prostate cancer
- Lung cancer
- Colorectal cancer
- Skin cancer (basal cell, squamous cell, melanoma)
- Bladder cancer
- Pancreatic cancer
- Leukemia and lymphomas
- Oral cancer
General Warning Signs
- Unexplained weight loss
- Unusual lumps or thickening
- Change in a mole or skin lesion
- Persistent cough or hoarseness
- Change in bowel or bladder habits
- Unusual bleeding
- Persistent unexplained pain
- Persistent fatigue
Diagnosis
- Screening tests (mammography, colonoscopy, cervical screening, low-dose CT for lung)
- Imaging (CT, MRI, PET, ultrasound)
- Biopsy and pathology
- Molecular and genomic testing
- Staging to determine extent of disease
Treatment
- Surgery
- Radiation therapy
- Chemotherapy
- Targeted therapy
- Immunotherapy
- Hormone therapy
- Stem cell transplantation
- Palliative and supportive care alongside curative treatment
Prevention
- Don't smoke; avoid secondhand smoke
- Maintain a healthy weight and stay active
- Eat a balanced diet rich in vegetables, fruits, and whole grains
- Limit alcohol
- Protect skin from UV (sunscreen, shade, no tanning beds)
- Get recommended vaccinations (HPV, hepatitis B)
- Follow recommended cancer screening schedules
When to See a Doctor
See a doctor for any of the warning signs above, and follow recommended screening for your age and risk factors.
Frequently Asked Questions
No. Many cancers, especially when detected early, can be cured or controlled long-term. Survival rates have improved substantially in recent decades.
Most cancers are sporadic — about 5–10% are strongly hereditary. Family history of certain cancers may justify genetic counseling or earlier screening.
There is no strong direct evidence that stress causes cancer, but chronic stress can affect health behaviors and immune function. Healthy lifestyle changes are valuable regardless.
References
- World Health Organization. Cancer Fact Sheet.
- American Cancer Society. Cancer Facts and Figures.
- National Cancer Institute. Cancer Information.