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Causes and methods to prevent Cancer (Sure Steps to Cancer Prevention - Part II) August, 2008.
This is in continuation of last month’s Newsletter on Cancer Prevention, wherein early indications of cancer were described and an outline of the causes of cancer in general were mentioned and exact steps to be taken in the event of a suspicion of cancer in a person were described.
More elaborate description of the causes and specific preventive measures are described in this Newsletter.
Tobacco:
Tobacco is the single largest preventable cause of cancer in the world today. It causes 80-90% of all lung cancer deaths, and about 30% of all cancer deaths in developing countries, including deaths from cancer of the oral cavity, larynx, oesophagus and stomach. Chewing tobacco as “gutka”, smoking beedies and cigarettes and inhaling snuff are very much prevalent in rural India and accounts for a large number of cancers in the intestinal tracts.
Prevention:
A comprehensive strategy including bans on tobacco advertising and sponsorship, tax increases on tobacco products, and “stop smoking” programmes can reduce tobacco consumption in many countries. The WHO Framework Convention on Tobacco Control, adopted in May 2003, aims to curb tobacco-related deaths and disease.
It is strange that no Government is willing to ban cultivation of Tobacco leaves!! This ban would hit at the root cause of tobacco related cancer and other diseases!!
Quit smoking to decrease your chances of having cancer. Also try to avoid secondary smoke; secondary smoke can also be deadlier.
Diet and general health:
There is a link between overweight and obesity to many types of cancer such as oesophagus, colorectum, breast, endometrium and kidney. Excess consumption of red and preserved meat may be associated with an increased risk of colorectal cancer.
Prevention:
Diets high in fruits and vegetables have a protective effect against many cancers. In addition, healthy eating habits that prevent the development of diet-associated cancers will also lower the risk of cardiovascular disease. For maximum protection, you should eat a wide variety of colorful fruits and vegetables, including garlic and onion, tomatoes, watermelon, leafy greens, broccoli, cauliflower, blueberries, carrots, and bell peppers.
Regular physical activity and the maintenance of a healthy body weight, along with a healthy diet, will considerably reduce cancer risk. National policies and programmes should be implemented to raise awareness and reduce exposure to cancer risk factors and provide information and support they need to adopt healthy lifestyles. Usefulness of Diet for good health and cancer free life go to the following link :
http://www.webmd.com/a-to-z-guides/features/antioxidants-and-omega-3-fats-functional-foods-to-boost-health?ecd=wnl_can_072208&spon=912345_0
Infectious Diseases:
Infectious agents are responsible for almost 22% of cancer deaths in the developing world and 6% in industrialized countries. Viral hepatitis B and C cause cancer of the liver; human papilloma virus infection causes cervical cancer; the bacterium Helicobacter pylori increases the risk of stomach cancer. In some countries the parasitic infection schistosomiasis increases the risk of bladder cancer and in other countries the liver fluke increases the risk of cholangiocarcinoma of the bile ducts. Unsafe Sex – you are suddenly exposed to not only HIV but also HPV. HPV is also known as Human Pappiliona Virus. Having this virus greatly increase a person’s chance of having anal, vulvar, cervical, or vaginal cancer.
Repeated infection in the prepucial sac in uncircumcised males having a tight phimosis is related to higher incidence of cancer penis in them than in circumcised men.
Prevention:
Preventive measures include vaccination for hepatitis and prevention of infection and infestation in other cases. There are tests that help a person find out if he or she has the HPV virus. A cytological examination of PAP smear will help in diagnosis. Circumcision in males when indicated and genital hygiene are useful measures.
Radiation risk.
Exposure to ionizing radiation is also known to cause to certain cancers. Excessive solar ultraviolet radiation increases the risk of all types of cancer of the skin.
Prevention:
Avoiding excessive exposure, use of sunscreen and protective clothing are effective preventive measures.
Carcinogenic Chemicals:
Asbestos can cause lung cancer; aniline dyes have been linked to bladder cancer; and benzene can lead to leukaemia.
Prevention:
The prevention of certain occupational and environmental exposure to these and other chemicals is another important element in preventing cancer.
Genetics:
Genetics is one of the causes of cancers. When your family has a history of cancer, the best thing to do is just take precaution. If your family has had a history of cancer, the mutated gene which causes cancer may have been passed down. Role of genetics in Breast cancer has been studied quite extensively. Even when there is a strong positive family history of breast cancer only a small fraction of them are linked to BRCA 1 and BRCA 2 mutations.
Certain factors increase your risk of having a BRCA mutation. You might be at increased risk of having a BRCA gene change if you have:
- A personal history of breast cancer diagnosed at a young age, breast cancer affecting both breasts (bilateral breast cancer), or both breast and ovarian cancers
- A family history of breast cancer in two or more close relatives, such as your parents, siblings and children
- A family member who developed breast cancer before age 50 on either your mother's or your father's side of the family
- A family history of breast cancer in more than one generation
- A male relative with breast cancer
- A family member who has both breast and ovarian cancers
- A family member with bilateral breast cancer
- A frequent occurrence of ovarian cancer within your family
- A positive BRCA1 or BRCA2 genetic test in a relative
- Ashkenazi (Eastern European) Jewish ancestry, with or without a family history of breast or ovarian cancer
Researchers have discovered that 2.3 percent of women of Ashkenazi descent carry a BRCA mutation — about five times greater than that of the general population.
If you have a BRCA mutation, your chances of developing breast or ovarian cancer during your lifetime are substantially higher than are the rates for the general population.
Prevention:
The value of genetic testing for breast cancer is a matter of debate . If your doctor or genetic counselor recommends genetic testing, you may be faced with a difficult decision. Genetic testing is expensive, and it may or may not be covered by your insurance. Also consider how you'll handle learning the test results — whether positive or negative.
Genetic testing is identifying women with BRCA1 or BRCA2 mutations for breast cancer, but preventive options are rather severe on the patients and takers are not many. They include Surgical removal of both breasts(95% reduction of cancer), removing both ovaries, drugs like Tamoxifen or Raloxephene(50% reduction in cancer in all these) over a prolonged period of time.
Gene Therapy:
Considerable research effort is now devoted to potential venues for gene therapy for individuals with genetic mutations or polymorphisms that put them at high risk of cancer. Meanwhile, genetic testing for high-risk individuals with enhanced surveillance or prophylactic surgery for those who test positive is already available for certain types of cancer including breast and colon cancers.
Chemo prevention of cancer:
Chemoprevention trials have had some positive results. Daily use of selective estrogen receptor modulators (tamoxifen or raloxifene) for up to 5 years reduces the incidence of breast cancer in high-risk women by about 50%.
Finasteride (an alpha-reductase inhibitor) lowers the incidence of prostate cancer, although the occurrence of more high-grade cancers in treated men is perplexing.
Other chemoprevention candidates include COX-2 inhibitors (which inhibit the cyclooxygenase enzymes involved in the synthesis of proinflammatory prostaglandins) to prevent colon and breast cancer, although the possibility of increased cardiovascular events may preclude their usefulness.
Statins have been proposed as cancer-prevention agents, but on review many retrospective studies show that they probably neither increase nor decrease cancer risk.
Early detection and Energetic treatment:
Fecal occult blood testing has been demonstrated to reduce both colon cancer incidence and mortality. Screening for colon cancer by colonoscopy and sigmoidoscopy may reduce both colon cancer incidence and mortality, presumably through the detection and removal of precancerous polyps.
Similarly, cervical cytology testing (using the Pap smear) leads to the identification and excision of precancerous lesions. Over time, such testing has been followed by a dramatic reduction of cervical cancer incidence and mortality.
Screening mammography and Breast self examination(BSE) have given very good results in the strategy against breast cancer. Go to following very recent link showing study that BSE is not very useful!!
http://www.webmd.com/breast-cancer/news/20080715/breast-self-exam-no-survival-benefit
Multivitamin and mineral supplements have been advocated for cancer prevention, but the evidence is insufficient to support their use.
References:
http://www.who.int/mediacentre/news/releases/2003/pr27/en/
http://mohfw.nic.in/pg56to67.pdf
http://mohfw.nic.in/pg56to67.pdf
http://bcbsma.medscape.com/viewarticle/561547
http://www.mayoclinic.com/health/genetic-testing-for-breast-cancer/HQ00350
About one third of all cancers are preventable and prevention is far better and more cost effective strategy in the overall management of this dreaded disease*.
Avoid any of the carcinogenic factors in your life, take expert help when there is any suspicion, regular medical and cancer check ups and leading a healthy life style will keep you and your family in good health and cancer free.
Best wishes,
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Dr. M.Mohan Rao.
Director and Senior Surgeon (Retired).
Dr U Mohan Rau Memorial Hospital, Chennai.
Chat with Dr Mohan Rao between 4 & 5 P.M. most of the days, when he is “Online” indicated in the Chat Box on Home Page.
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