This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Which of the following strategy has been recommended to reduce the heredity risk for ovarian cancer in women with BRCA - 1 and BRCA - 2 mutations: 
Select and explain. 
A. Use of oral contraceptive pills, B. Screening with transvaginal ultrasound, C. Screening with CA - 125, D. Prophylactic oophorectomy
D: Prophylactic oophorectomy
Answer: D: Prophylactic oophorectomy 
Explanation: As discussed in previous question:
• BRCA-1 and BRCA-2 are tumour suppressor genes.
• Individuals who inherit mutations of BRCA-1 and BRCA-2 are highly susceptible for the development of hereditary breast or ovarian cancer. The mutations are inherited as autosomal dominant.
Strategies for prevention of hereditary ovarian cancer
• Genetic testing for susceptibility to ovarian cancer is rapidly becoming integrated into the clinical practice of oncology.
Strategies have been adopted to reduce the incidence of ovarian cancer in patient with BRCA-1 and BRCA-2 mutations.
a. Prophylactic oophorectomy:
“The only proven way to prevent ovarian cancer is surgical oophorectomy. As another possible site of disease among these high risk patients is fallopian tube therefore should be removed. IN BRCA 1 or BRCA-2 mutation carriers, prophylactic bilateral salpingo-oophorectomy (BS0) may be performed on either completion of childbearing or at age 35. In these patients, the procedure is approximately 90% effective in preventing epithelial ovarian cancer. In women with HNPCC, the risk reduction approaches 100%.”
• Additional benefit of prophylactic oophorectomy is that the risk of breast cancer is reduced by 50-80%.
b. Oral contraceptive pills:
• Data received from a multicenter control of genetic screening centers indicates that the use of oral contraceptive pill is associated with 50% decreased risk for developing ovarian cancer in women who have mutation in either in BRCA - 1 or BRCA - 2. However there is short term increased risk of developing breast cancer.
c. Role of screening with CA 125 and transvaginal ultrasound:
“In BRCA1- BRCA2 mutation carriers who donot wish to undergo prophylactic surgery a combination of through pelvic examination, transvaginal sonographic examination and CA125 blood testing should be done”.
• Best method of prevention: Prophylactic hysterectomy and BSO at 35 years or as soon as family is complete.
• 2nd line: OCP’s + screening
• Screening: TVS + Ca 125 started at 35 years and done every 6 or 12 months, breast screening by MRI and mamography at 30 years done annually.