Disease at a Glance: Cancer
Cancer refers to a group of diseases characterized by unregulated and out-of-control cell growth. The human body is made up of trillions of living cells – these building blocks of life grow in an orderly manner. They know when to grow and divide and when to die. Unlike healthy human cells, cancer cells keep growing, refusing to stop even when the body doesn’t need new cells. This uncontrolled growth of cells group together to form a mass – this is called a tumour (the medical name is Neoplasm).
Not all tumours are cancerous – some just grow big and may press on nearby tissues, but never invade or destroy them. These are called benign tumours. That’s the key difference between cancerous tumours and benign tumours – the latter doesn’t spread to other parts of the body and, hence, may not always be life-threatening. Cancer cells don’t just grow uncontrollably, they also invade and destroy nearby healthy tissues – cancer cells can even reach distant body parts through the lymphatic system or the bloodstream.
A cancer is named for the place where the uncontrolled cell growth begins, irrespective of which organs or tissue it spreads to. For example, a cancer that originated in the kidney but has spread to the lungs will still be termed kidney cancer. Where the cancer spreads to is referred to as secondary tumour – in the example mentioned above, lung cancer would be the secondary tumour. There are more than 200 types of cancers – cancer can develop in any type of cell in the body – but six broad categories are used to classify the disease.
1) Carcinoma: Cancer that begins in tissues that line the inner or outer surface of an organ - this account for 80% of all cancer cases
|2) Sarcoma: Cancer cells located in connecting tissues like bones, muscle, cartilage|
|3) Lymphoma: Cancer that begins in the nodes or glands of the lymphatic system|
4) Leukemia: Cancer of the bone marrow; also called blood cancer
|5) Myeloma: Cancer that grows in the plasma cell of the bone marrow|
|6) Adenoma: Cancer that arises in glandular tissues like the thyroid gland, pituitary gland, adrenal gland, etc.|
The prognosis in case of Carcinoma depends on the Grade of Carcinoma (starting from Grade 1 to Grade 4) when diagnosis is made and the treatment is instituted. Higher the grade of the lesion at the time of diagnosis, the worse is the prognosis. Malignant tumours made of bone, cartilaginous tissue, muscle tissue, vascular tissue and haemopoietic tissue (tissues connected with formation of blood) are generally considered to be Sarcomas - the 5-year survival rate of people with soft tissue sarcoma is around 50%.
Lymphoma is a type of Blood Cancer that often originate in the lymph nodes but thereafter affect other organs. They are closely related to Lymphoid Lukaemia, which also originate in the lymphocytes, but typically involve other circulating blood and bone marrow tissues. The 5-year survival rate of lymphoma is 82% in localized lesions, 77.5% in metastasis spread to regional lymph nodes, 59.9% in cases with metastasis at distant areas.
Adenoma is a benign tumour of the epithelial tissue with glandular origin, but it may be transformed into a malignant form which is known as adenocarcinoma. Prognosis varies in epithelial tissues of different organs, but is generally much better than many other rapidly spreading and fast invading malignant conditions.
There is no single cause of cancer – scientists attribute it to a variety of factors that range from genetic, environmental, chemical & radiation exposure, immune system, hormones, etc. Symptoms of cancer are also quite varied, depending on the location, how big is the tumour and where it has spread. Some cancers can be felt, while others are less apparent. Because cancer cells use the body’s energy to grow, tell tale signs include fatigue, fever, unexplained weight loss, anemia, etc. Unfortunately, these symptoms are common to many diseases!
Cancer treatment depends on the kind of cancer and how much it has spread. There’s no single treatment for the disease – it’s usually a combination of therapies and palliative care.
Key Diagnostic Tests: Biopsy, Endoscopy, MRI & Ultrasound, Mammogram, PAP Smear, etc.
Additional Tests: CBC, Tumour Marker Test, Blood Protein Test, etc.
Doctor Specialty: Oncologist (Medical / Surgical / Radiation)
Patient Helpline: 022-24139445 / 51 (Indian Cancer Society)
1) American Cancer Society (www.cancer.org)
2) Stanford Medicine Cancer Institute (www.cancer.stanford.edu)
3) Indian Cancer Society (www.indiancancersociety.org)
4) Medical News Today Knowledge Centre (www.medicalnewstoday.com/knowledge-center)
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