In the human body, cells grow and divide continuously. As the old cells die, they are replaced with new ones. However, certain genetic changes may interfere with this process resulting in uncontrolled division of cells — and this process is called cancer. When cancer cells form a mass, it is called a tumor. This tumor could be benign or malignant. A benign tumor may grow bigger in size, but does not spread to other organs. A malignant tumor is commonly called cancer, and implies a mass that spreads to other organs. Blood cancer (leukemias) and lymphomas are cancers that do not form a tumor.

Types of cancer

Various types of cancers include:

Carcinomas (begin in the skin or the tissue that covers the surface of internal organs and glands like prostate, breast and liver), sarcomas (cancer of connective tissue like nerves and muscles), leukemias (cancer of the blood) and lymphomas (cancer of the lymphatic system like Hodgkin’s lymphoma).

Can cancer cells spread?

Metastasis (pleural metastases) is a condition when the cancer cells spread to distant organs via blood or lymphatic system. Occasionally, cancer cells may break off from the original tumor and ‘seed’ to the nearby areas. Cancer can metastasize to any organ in the body. However, each cancer has a predilection for certain preferred organs, where it is more likely to spread. Example, prostate cancer more commonly spreads to bones; colon cancer spreads to lung and liver etc.

How is cancer diagnosed?

Many cancer patients are asymptomatic. The disease may be an incidental finding while conducting routine tests. Occasionally, it may be discovered during screening tests like colonoscopy, mammography and pap smear. A biopsy may be indicated for confirmation of the diagnosis. A PET scan is useful in diagnosing metastases.

Treatment of cancer

Cancer management is a multidisciplinary team effort that involves liaison amongst oncologist, oncosurgeon, radiation therapist, pain management physician, pathologist, nutritionist and the radiologist. If diagnosed early enough, these patients may live a normal life span. Those surviving long may need dedicated pain management. Palliative care helps in easing life of the terminally ill patients. Please refer to my blog — Palliative care in cancer patients by Dr Vivek Loomba — for details of palliative treatment in these patients.

Side effects of cancer treatment

Various cancer management treatments may have side effects like immune suppression, hair loss, nausea, vomiting etc. Immune suppression is a serious side effect, as it may predispose patients to opportunistic infections. So these patients need a well balanced diet, and also should take adequate precautions to avoid risk of any infections.