For many years the treatment of cancer was surgery and then came radiation. Chemotherapy was the by-product of the world wars; it was a shotgun remedy killing anything that grew rapidly. Cancer cells grew rapidly and were killed; normal cells that grew rapidly were also killed. The killing of normal cells resulted in side effects. Chemotherapy cured, but the cure came at a cost.
Rationale on therapy
Cancer develops because cells acquire the ability to grow uncontrollably. Scientists have got an insight into the mechanism that causes cancer only in the last three decades. This insight gave a big impetus to rational development of drugs against the disease.
Drugs, which unlike chemotherapy, would attack the mechanisms of cancer. Two types of drugs have been added to the armamentarium against or cancer. The first is ‘Targeted Therapy’ and the second is ‘Immunotherapy’.
- Targeted therapy targets the differences between cancer cells and normal cells.
- Immunotherapy restores the body’s immunity against cancer.
The ‘targets’ of Targeted Therapy are either changes in the cell that have turned cancerous or a protein that is mainly present in the cancer cell. One of the first successes of ‘Targeted Therapy’ was a leukaemia called chronic myeloid leukaemia. Then same drugs were used against breast cancer, lymphoma, colon cancer, lung cancer and kidney cancer.
Anti-cancer immunity may be stimulated by the used of checkpoint inhibitor monoclonal antibodies, t-cell therapy, oncolytic virus therapy, which are cancer vaccines and viruses capable of killing cancers. The development of these fighting agents is progressing at a very rapid pace. They are effective in lung cancer, kidney cancer and melanoma. they are also being evaluated for many other cancers.
T-lymphocytes are a type of white blood cells (WBC) that kill foreign cells. A form of T-cell therapy is now available to modify patient’s T-lymphocytes then give them an ability to kill the cancer cells. The therapy is expensive and available in a very few centres, with time more cancer will be cured using this CAR-T, and the cost of therapy will reduce.
All drugs or therapies must be considered only after recommendations and guidance of an Oncologist.
Changes over the years
The impact of drugs on the cancers is not fully appreciated. The last 40 years have seen a tenfold increase in the survival of cancer patients, much of this because of drugs.
The favourable impact of these developments will be seen in the coming years.
Globally, women are more prone to cancer; cancers in women include 88 per 100,000 and 73 per 100,000 in men.
The author is a medical oncologist at S.L. Raheja Hospital in Mahim