Oncology (cancer)

Cancer is a group of diseases that occur when cells grow abnormally and divide uncontrollably, potentially invading nearby tissues and spreading to other parts of the body. Cancer can be caused by gene changes that happen over a person's lifetime, or by inherited faulty genes.

Oncology is the branch of medicine that deals with the diagnosis, treatment, and management of cancer.

*Types of Cancer*

1. _Carcinoma_: Cancer that originates in epithelial cells, such as breast, lung, colon, and prostate cancer.
2. _Sarcoma_: Cancer that originates in connective tissue, such as bone, cartilage, and fat.
3. _Leukemia**: Cancer that originates in blood cells.
4. _Lymphoma_: Cancer that originates in the immune system.
5. _Melanoma_: Cancer that originates in skin cells.

*Stages of Cancer*

1. _Stage I_: Cancer is localized and has not spread.
2. _Stage II_: Cancer has spread to nearby tissues.
3. _Stage III_: Cancer has spread to lymph nodes or distant sites.
4. _Stage IV_: Cancer has spread to multiple distant sites.

*Cancer Diagnosis*

1. _Biopsy_: Removal of tissue or cells for examination.
2. _Imaging tests_: X-rays, CT scans, MRI scans, and PET scans.
3. _Blood tests_: Tumor markers and complete blood counts.
4. _Physical examination_: Examination of the body for signs of cancer.

*Cancer Treatment*

1. _Surgery_: Removal of tumor and surrounding tissue.
2. _Chemotherapy_: Use of drugs to kill cancer cells.
3. _Radiation therapy_: Use of radiation to kill cancer cells.
4. _Immunotherapy_: Use of the immune system to fight cancer.
5. _Targeted therapy_: Use of drugs to target specific cancer cells.
6. _Hormone therapy_: Use of hormones to slow cancer growth.
7. _Stem cell transplantation_: Replacement of damaged stem cells.

*Cancer Management*

1. _Pain management_: Control of cancer-related pain.
2. _Nutrition therapy_: Management of nutrition and diet.
3. _Palliative care_: Relief of symptoms and stress.
4. _Rehabilitation_: Physical, occupational, and speech therapy.
5. _Psychological support_: Counseling and support groups.

*Cancer Prevention*

1. _Screening tests_: Early detection of cancer.
2. _Healthy lifestyle_: Avoid tobacco, maintain healthy weight, exercise regularly.
3. _Vaccinations_: HPV, Hepatitis B, and other cancer-preventing vaccines.
4. _Genetic testing_: Identification of genetic mutations.
5. _Chemoprevention_: Use of medications to prevent cancer.

*Common Cancers*

1. _Breast cancer_
2. _Lung cancer_
3. _Colorectal cancer_
4. _Prostate cancer_
5. _Skin cancer_

*Oncology Subspecialties*

1. _Medical oncology_
2. _Surgical oncology_
3. _Radiation oncology_
4. _Pediatric oncology_
5. _Gynecologic oncology_

*Cancer Research*

1. _Basic research_: Study of cancer biology.
2. _Translational research_: Development of new treatments.
3. _Clinical trials_: Testing of new treatments.
4. _Epidemiology_: Study of cancer patterns and risk factors.
5. _Cancer genetics_: Study of genetic mutations.