Oncology is a branch of medicine involving the prevention, diagnosis and treatment of cancer. The major disciplines within oncological medicine are distinguished primarily by method of treatment, and include:

  • Medical oncology refers to the use of drugs of various types to treat cancer.
    • Chemotherapy – The use of cytotoxic agents to inhibit mitosis or damage the DNA of cancer cells, slowing or stopping their growth; side effects result from damage to healthy, non-cancerous cells.
    • Hormone therapy – Used on hormone-dependent or hormone-sensitive tumors; drugs administered to reduce or block hormone production to inhibit cancer cell growth and proliferation; can be effective for treatment of breast cancer, prostate cancer, ovarian cancer and uterine cancer.
    • Targeted therapy – Inhibiting tumor development and growth with non-cytotoxic drugs that target genes or proteins specific to cancer cells; reduces damage to healthy cells caused by traditional chemotherapy drugs.
    • Immunotherapy – A newer approach that aims to strengthen the cancer-fighting immune response with patient-specific and tumor-specific agents such as lab-modified T-cells; includes vaccines that sensitize the immune system to cancer-specific antigens, allowing tagging, targeting and destroying of cancer cells.
  • Radiation oncology focuses on treatment with ionizing radiation to kill or incapacitate cancer cells by inducing damage to their DNA. Therapy can be administered internally or externally. Most commonly, external beam radiotherapy (EBRT) is used to precisely direct high-energy X-rays to the site of a malignancy. Scenarios most conducive to radiotherapy include:
    • Anatomically unresectable (unremovable) cancers
    • Patients medically unfit for surgery due to other chronic disease states
    • Tumors in close proximity to critical blood vessels or nerves
    • Pre-operative (to shrink the tumor and facilitate surgical removal)Drawing of EBRT machine
    • Post-operative (to diminish risk of tumor recurrence)
  • Surgical oncology relates to the use of physical removal techniques to prevent, diagnose, stage and treat cancer.
    • Preventative surgery is performed when necessary to remove body tissue at risk of becoming cancerous, before any signs of cancer are present.
    • Diagnostic surgery, in most cases, means the procedure of taking a biopsy — a small piece of tissue from the affected region that is then used for microscopic or other analysis to determine the presence of cancer and its type.
    • Staging surgery is done to reveal the size or amount of cancerous growth and the extent to which it has spread; future treatment can be guided by tissue-sampling areas around the cancer to determine the state of surrounding lymph nodes or organs.
    • Curative surgery (or primary surgery) can be performed in cases where malignancy is localized to one part of the body, with a high likelihood that it can be completely removed. This can be done by itself or in conjunction with other treatments such as chemotherapy or radiotherapy.


How Surgery Is Used for Cancer. American Cancer Society. Available from URL: https://www.cancer.org/

Medical Oncology, Chemotherapy Treatment for Cancer in India - HCG Cancer Hospitals. Available from URL: https://www.hcgoncology.com/.

Oncology - Latest Research and News. Nature. Available from URL: https://www.nature.com/.

Radiation Oncology - Overview. Mayo Clinic. Available from URL: https://www.mayoclinic.org/.

Therapeutic Potential of NAD-Boosting Molecules: The in Vivo Evidence. PubMed Central (PMC). Available from URL: https://www.ncbi.nlm.nih.gov/.

Tidy, Colin. Radiotherapy. Patient. Available from URL: https://patient.info/doctor/radiotherapy-pro.

Talk To An Expert