CANCER AND ITS TREATMENT

Cancer is a diseased growth in the body that often causes death. Cancer cells are referred to as oncogenes. Oncology is defined as the study of an abnormal mass of tissue or an abnormal cell population with a capacity for progressive growth. Persistence of growth is an important feature of cancerous or tumour cell that distinguishes them from other neoplastic cells. The neoplasm or new growth can either be benign (not dangerous) or malignant (harmful or dangerous).




Malignant tumours are divided into two groups viz; carcinomas and sarcomas. Carcinomas are composed of epithelial cells while sarcomas consist of connective tissues. Malignant cells prefer anaerobic glycolysis and produce more lactic acid than normal cells. Examples of cancers include lung cancer, breast cancer, cervical cancer and prostate cancer.




Two important concepts that are necessary for the treatment of cancers include growth fraction and cell cycle.Growth fraction has the following information; proportion of rapidly dividing neoplastic cells that effectively respond to chemotherapy, percentage of actively dividing cells in the cell cycle, an index of tumour enlargement. The cell cycle have various phases such as the synthesis phase (S-phase),mitosis phase (M-phase),gap phase represented by G1 and G2 respectively(here RNA synthesis ,protein synthesis and production of initiator proteins occur.),G0 represents the period when the cell go into a state of rest.



Cancer can be treated through the combination of three methods viz; surgery, radiotherapy and chemotherapy. Surgery involves the removal of malignant tumours from the affected part. For instance,lumpectomy involves the removal of malignant tumours from the breast. Radiotherapy employs the use of controlled radiation to treat malignant tumours. Effective chemotherapeutic approach to the treatment of cancer is based on the proper understanding of growth fraction and cell cycle concept. Growth fraction is an index of tumour enlargement and a higher growth fraction yields better results with chemotherapy.




Chemotherapeutic or anti-tumour drugs have the ability of affecting the various phases in the cell cycle. Antimetabolites are S-phase specific and examples include 5-fluorouracil,6-mecarptopurine,metotextrate and arabinosylcytosine. Vinca alkaloids are M-phase specific; two compounds are used which are vincaleucoblastine(VBL) and vincristine (VCR). Non-cell specific chemotherapeutic agents include alkylating agents such as nitrogen mustard, triethylenemelamine, and triethylene phosphorimide and antibiotics such as Actinomycin D, Adriamycin and so on.




It is also pertinent to note that anti-tumour drugs are associated with toxicity. Their therapeutic dose should be strictly obeyed. Examples of such effects include bone marrow depression, depletion of blood cells, loss of hair and so on.




The use Positron Emission Tomography (PET) scan is invaluable in the detection of cancerous growth in organs of the body.Conclusively,early detection of cancerous growth would ultimately enhance effective treatment of carcinomas and sarcomas occurring in humans.