Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. Not all tumors are cancerous; benign tumors do not spread to other parts of the body. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss and a change in bowel movements. Cancer Treatment Kolkata Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells as you need them, replacing old cells that die. Sometimes this process goes wrong. New cells grow even when you don't need them, and old cells don't die when they should. These extra cells can form a mass called a tumor. Tumors can be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors can invade nearby tissues. They can also break away and spread to other parts of the body.

Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for where they start. For example, lung cancer starts in the lung, and breast cancer starts in the breast. The spread of cancer from one part of the body to another is called metastasis. Symptoms and treatment depend on the cancer type and how advanced it is. Most treatment plans may include surgery, radiation and/or chemotherapy. Some may involve hormone therapy, immunotherapy or other types of biologic therapy, or stem cell transplantation.

What causes Cancers?

Best Cancer Treatment Doctor in Kolkata1) Chemical or toxic compound exposures:
Benzene, asbestos, nickel, cadmium, vinyl chloride, benzidine, N-nitrosamines, tobacco or cigarette smoke (contains at least 66 known potential carcinogenic chemicals and toxins), asbestos, and aflatoxin

2) Onizing Radiation:
Uranium, radon, ultraviolet rays from sunlight, radiation from alpha, beta, gamma, and X-ray-emitting sources

3) Pathogens:
Human papillomavirus (HPV), EBV or Epstein-Barr virus, hepatitis viruses B and C, Kaposi's sarcoma-associated herpes virus (KSHV), Merkel cell polyomavirus, Schistosoma spp., and Helicobacter pylori; other bacteria are being researched as possible agents.

4) Genetics: A number of specific cancers have been linked to human genes and are as follows: breast, ovarian, colorectal, prostate, skin and melanoma; the specific genes and other details are beyond the scope of this general article so the reader is referred to the National Cancer Institute for more details about genetics and cancer.

It is important to point out that most everyone has risk factors for cancer and is exposed to cancer-causing substances (for example, sunlight, secondary cigarette smoke, and X-rays) during their lifetime, but many individuals do not develop cancer.

Recently, other risk factors have been added to the list of items that may increase cancer risk. Specifically, red meat (such as beef, lamb, and pork) was classified by the International Agency for Research on Cancer as a high-risk agent for potentially causing cancers; in addition processed meats (salted, smoked, preserved, and/or cured meats) were placed on the carcinogenic list.

What are the Symptoms and Signs of Cancers?

Cancer Doctor in Kolkata . Change in bowel or bladder habits
. A sore throat that does not heal
. Unusual bleeding or discharge (for example, nipple secretions or a "sore" that will not heal that oozes material)
. Thickening or lump in the breast, testicles, or elsewhere
. Indigestion (usually chronic) or difficulty swallowing
. Obvious change in the size, color, shape, or thickness of a wart or mole
. Nagging cough or hoarseness

Other signs or symptoms may also alert you or your doctor to the possibility of your having some form of cancer. These include the following:

. Unexplained loss of weight or loss of appetite
. A new type of pain in the bones or other parts of the body that may be steadily worsening, or come and go, but is unlike previous pains one has had before
. Persistent fatigue, nausea, or vomiting
. Unexplained low-grade fevers with may be either persistent or come and go
. Recurring infections which will not clear with usual treatment