Prevention of Cancer PART – 18
(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: In last part, we discussed some very important points 1. To reduce use of CT scan, PET scan in non emergency situations, follow up post cancer treatment. Use USG, MRI where feasible. In emergency, or at time of new diagnosis of cancer, use best possible radiology studies without worrying about radiation exposure. Reducing radiation exposure in children is much more important. 2. Vaccines for HPV, Hepatitis B. for health care workers hepatitis B vaccine is very important. 3. No medicine proven for general public with regard to prevention of cancer. For some high risk patients, certain medicines can be considered. 4. No multivitamin supplements also prevent cancer. some high dose supplements may even be harmful.
Once again highlighting the fact that there is no shortcut. And important to follow overall healthy lifestyle. For prevention of not only cancer, but so many other diseases.
In last part, you did mention role of surgery once in cancer prevention. How does that work?
Ans: Surgery in cancer prevention is for very selected patients. These are high risk individuals based on strong family history and presence of a genetic mutation. This is important to know as some patients have a strong family history and they are obviously very concerned about what they can do to prevent cancer. This decision requires very careful evaluation and significant counselling pre and post genetic testing as well as pre and post surgery. Now there are formally trained genetic counsellors available in India including our state of Gujarat. They take a detailed family history looking at whole pedigree and then suggest what genetic tests are to be done, and implications of both a positive and a negative genetic test. If the test is negative, it does not mean there is no increase in risk of cancer. if the test is positive, it does not mean cancer will certainly occur. Some recent studies have shown that even with family history and genetic mutation, such as BRCA in breast cancer, healthy lifestyle does reduce risk of breast cancer.
For many individuals, genetic testing is psychologically very overwhelming. It can leave them with a lot of anxiety for many years and significantly interfere with their quality of life. Hence commercially available genetic profiles should not be routinely ordered for person without strong family history or other specific reasons. Also, it should be only after pre and post test counselling to understand implications of these tests. And if person is not comfortable after pre test counselling, testing should be deferred or avoided altogether.
Many commercial genetic profiles are available today in India as well, even used as part of routine health check up. Mostly without pre test counsellor consultation. It is strongly recommended to avoid such testing without counselling, and without understanding implications. It can lead to anxiety, depression, pathological fear. In addition, it can have impact on health insurance, and potentially even employment, and relationships.
Que: Thank you for those very important points, especially about genetic profiles for an otherwise healthy person. And it is very good to know we have genetic counsellors available. Then who are the right candidates?
Ans: Right candidates for this testing are individuals with a strong family history of cancer. Most commonly breast, ovary, colon, prostate cancer. For most other cancers, even if there is a strong family history or history of multiple different types of cancers, there is a rarely a genetic mutation that can be found by current testing methods. However, anyone who is very concerned, can meet a genetic counsellor and understand the chances of finding something on a genetic test, and what to do if a test is positive.
BRCA 1, BRCA 2 are the most commonly done genetic test in mainly patients with strong family history of breast cancer. If one of these tests is positive, there is potentially lifetime risk of about 50% for breast cancer, and about 25% for ovary cancer. ovary cancer risk is generally after age 40. Risk estimates vary significantly in different studies and populations however.
For these patients, Bilateral Mastectomy (removing both breasts) reduces risk of breast cancer by about 90%. This surgery is not indicated for those who have BRCA mutation, but no family history of breast cancer.
Bilateral removal of ovaries and fallopian tubes is also and option in BRCA mutation carriers. After age 35-40, once child bearing has been completed. This surgery reduces risk of ovary cancer by about 80%. However there is some controversy with regard to benefits of this surgery.
Lynch syndrome patients: recommended surgical options are 1. Total colon removal to reduce risk of colon cancer. 2. Total hysterectomy with bilateral ovary and fallopian tubes – to reduce risk of endometrial and ovary cancers.
Que: Oh! Removing both breasts, or ovaries, or total colon is a big decision.
Ans: Yes, that is why counselling is very important before this surgery. As noted earlier, this surgery can have major impact on woman’s psychology, sexuality, relationships. Also, premature menopause from ovary removal has additional health effects e.g. increased cardiovascular risk, osteoporosis, metabolic changes.
Fortunately, this type of risk reduction surgeries are indicated in few people overall. Only about 5-10% of all cancers are hereditary. And few of these meet all the criteria for such surgeries.
June 15, 2023 Dr Chirag A. Shah; M.D. Oncology/Hematology (USA), 9998084001. Diplomate American Board of Oncology and Hematology. Ahmedabad. email@example.com www.shyamhemoncclinic.com