germline mutations in the tumor suppressor genes brca1 and brca2 account for 3% to 5% of all breast cancer cases and 10% to 15% of ovarian cancer cases . the lifetime risk of breast cancer in brca1 and brca2 mutation carriers is estimated at 47% to 66% and 40% to 57% , respectively . the ovarian cancer risk in brca1 and brca2 mutation carriers is estimated at 35% to 46% and 13% to 23% , respectively . the median onset age for breast cancer in brca mutation carriers is 40 to 50 years , while that for sporadic cases is 60 to 70 years . previous studies conducted in unaffected brca mutation carriers have indicated that prophylactic mastect - omy effectively reduces the residual lifetime risk of breast cancer to < 5% . however , this evidence was derived from retrospective and short - term follow - up prospective studies , so it is not clear whether a bilateral risk - reducing mastectomy ( rrm ) provides better survival when compared with intensive surveillance . risk - reducing salpingo - oophorectomy ( rrso ) has been demonstrated to reduce risk of ovarian cancer to 85% , also derived from retrospective and short - term follow - up . they recommend rrso for brca mutation carriers especially upon completion of child - bearing in the national cancer center network guidelines because of the absence of reliable methods of early detection and the poor prognosis associated with advanced ovarian cancer , although they hold rrm to an option for brca mutation carriers . in japan , risk - reducing surgery as well as genetic counseling or genetic test is outside the health insurance , so we perform risk - reducing surgery for brca mutation carriers in the limited hospital facilities after the ethics committee granted permission . the safety and feasibility of nipple - sparing mastectomy ( nsm ) or skin - sparing mastectomy ( ssm ) in brca mutation carriers is debatable , and a consensus of which procedure should be performed has not yet been reached . we report a 38-year - old japanese women diagnosed with brca2 mutation that underwent prophylactic bilateral ssm with excision of the nipple to preserve the areola skin . furthermore , we provide a review of the literature on the risk management of brca mutation carriers , especially the concepts and procedures of rrm . a 38-year - old japanese woman was diagnosed as a brca2 mutation carrier after genetic counseling and testing and was referred to kitano hospital in april 2014 to undergo risk - reducing surgery . her father had been diagnosed with prostate cancer when he was 49 years old ; he had died from the disease 2 years later . her mother was alive but had a history of arrhythmia that was diagnosed when she was 64 years old . her paternal grandmother had been diagnosed with breast cancer when she was 54 years old and had died from the disease 10 years later . although her maternal grandfather died at the age of 72 years because of metastatic cancer , the precise details were not known . her ancestry was japanese , and she was unaware of any ashkenazi jewish heritage . because of her family history , the fact that she was a widowed mother with three children , and her knowledge of hereditary breast and ovarian cancer , she worried about that , and consulted a genetic counselor to undergo brca mutation testing . after genetic counselor showed all of the risk management options for brca mutation carriers , frequent mammography , breast magnetic resonance imaging ( mri ) , clinical breast examinations , chemoprevention , and prophylactic surgery including extent of cancer risk reduction , risks associated with surgeries , reconstructive options , management of menopausal symptoms , and reproductive desires , addressing psychosocial , social , and quality of life aspects , she finally desired rrm and rrso . the ethics committee granted permission for the rrm in may 2014 , and we provided informed consent prior to the rrm . the need for rrso remained to be discussed because of concerns associated with rrso such as menopausal disorders caused by iatrogenic fertility . breast mri showed rapid early enhancement with linear and ductal distribution in both the breasts , and the possibility of ductal carcinoma in situ could not be ruled out . axillary node enlargement was not observed . in july 2014 , to improve aesthetic and psychological outcomes according to her preference , she underwent a bilateral ssm with excision of the nipple to preserve the areola skin . using indigo carmine , we demarcated the perimeter of the breast tissue preoperatively to ensure complete excision of the mammary gland . immediate breast reconstruction was performed using the standard prosthetic reconstructive technique of two - stage expander - implant reconstruction . on pathological examination she was disease - free at a 1-year follow - up and her general condition was good . although the american society of clinical oncology has previously recommended that brca mutation testing should be conducted only for those with at least a 10% likelihood of carrying a mutation , it is currently recommended for any individual with a suggestive family history if the result would affect the magnitude of medical management . risk management for brca mutation carriers includes frequent mammography , breast mri , clinical breast examinations , chemoprevention , and prophylactic surgery . previous studies conducted in unaffected brca mutation carriers have indicated that prophylactic mastectomy effectively reduces the residual lifetime risk of breast cancer to < 5% . conducted a prospective study of 139 pathogenic brca1/2 carriers , among whom , 76 underwent prophylactic mastectomy and 63 were followed by regular surveillance . they showed that there were no cases of breast cancer after rrm with a mean follow - up 2.91.4 years , whereas there were eight cases of breast cancers in the surveillance group after a mean follow - up of 31.5 years . conducted a retrospective study of 639 women with a family history of breast cancer that underwent prophylactic mastectomy . with a median follow - up of 14 years , they reported that prophylactic mastectomy was associated with a 90% reduction in the incidence of breast cancer , with only seven women developing breast cancer . however , randomized controlled trials to evaluate the potential impact of rrm on survival have not been conducted , and it remains unclear whether bilateral rrm improves survival compared with intensive surveillance . the only available data is derived from risk estimates assessed using mathematical models of risk - reducing interventions . developed a monte carlo model of breast screening with annual mammography plus mri in subjects aged 25 to 69 years ; rrso was performed in those aged 40 to 50 years and rrm was performed in those aged 25 to 50 years . they reported that rrm at age 25 plus rrso at age 40 years maximizes survival probability , substituting mammography plus mri screening for rrm seemed to offer comparable survival . as far as chemoprevention is concerned , tamoxifen reduced breast cancer incidence among healthy brca2 carriers by 62% . in this case , after we discussed all of the risk management options for brca mutation carriers recommended by the national comprehensive cancer network ( nccn ) guidelines , she has finally chosen to have rrm , because she has believed rrm might release from the fear of future cancer more than other cancer preventive options . she made choice to have rrm by her responsibility that 37-year - old widowed mother with three young children , concerning that prophylactic mastectomy effectively reduces the residual lifetime risk of breast cancer to < 5% which is superior than chemoprevention , although addressing psychosocial effect of mastectomy , and risks associated with surgeries . bresser et al .   reported that 95% of women opted for rrm because of decreased cancer - related psychological distress . they tend to have young children and a greater awareness of the genetic nature of cancer in the family compared with those who opt for regular surveillance , as well as in this case . for brca1 or brca2 mutation carriers at high risk for ovarian cancer , the absence of reliable methods of early detection and the poor prognosis associated with advanced ovarian cancer have impelled them to the performance bilateral rrso after completion of childbearing , ideally by age 35 to 40 years . as to the chemoprevention option , oral - contraceptive use protected against ovarian cancer both for carriers of the brca1 mutation ( odds ratio , 0.5 ; 95% confidence interval , 0.30.9 ) and for carriers of the brca2 mutation ( odds ratio , 0.4 ; 95% confidence interval , 0.21.1 ) . in this case , the need for rrso remained to be discussed in the ethics committee , and she underwent rrm at first before rrso , as following reasons : firstly , the most important reason is that there is the difference between the risk of breast cancer and of gynecologic cancer in age of 30s in brca2 mutation . the timing of rrso is controversial , while nccn guidelines panel recommends rrso for women with a known brca1 or brca2 mutation , typically between ages 35 and 40 years and upon completion of childbearing . it is well established that among women with brca2 mutation , the risk of gynecologic cancer is only 2% to 3% by the mean age of 50 years , while it increases in the late 30s in women with brca1 mutation . however , the risk of breast cancer is over 20% in 30s in women with brca2 mutation . secondly , mutation carriers who undergo rrso at a young age face medical problems such as osteoporosis , and cardiovascular disease , as well as quality - of - life issues associated with menopause , hot flashes , vaginal dryness , sexual dysfunction , sleep disturbances , and cognitive changes . thirdly , women who undergo bilateral mastectomy but who have ovaries intact can use oral contraceptive safety for protecting against ovarian cancer . oral contraceptive use has been associated with a small increase in the risk of breast cancer in young and old women . in a large meta - analysis , current use of oral contraceptives was associated with a relative risk 1.2 for breast cancer . she has not use oral contraceptive even after rrm , because she desire to have children , but she can take oral contraceptive after she gave up having children . fourthly , short - term hormone replacement therapy after rrso may be useful after rrm to improve their quality - of - life for women without increasing the risk of breast cancer , when no history of breast cancer has confirmed pathologically . as far as the method of rrm is concerned , ssm and nsm are increasingly performed instead of the conventional total mastectomy to allow for immediate breast reconstruction and to achieve a natural aesthetic outcome . the oncological risk associated with remaining mammary gland is unclear , and there remains a small risk of cancer arising beneath the nipple and areola in nsm . reynolds et al .   evaluated 62 nipple - areolar complex ( nac ) tissues from 33 female brca1/2 mutation carriers who underwent mastectomy and found that 24% of nacs contained terminal duct lobular units ( tdlus ) , with only 8% found in the nipple papilla , and they estimated that nsm might be appropriate and oncologically safe for women with brca mutation carriers , but tdlus can be found in the nac and are more likely at the base of the nipple , so the significance of this for long - term risk is unknown . however , hartmann et al .   reported that no significant difference in the incidence of breast cancer between women who underwent subcutaneous mastectomy and those who underwent total mastectomy . the prose study followed 105 brca1/2 mutation carriers who underwent a bilateral prophylactic mastectomy , at least 30% of whom had subcutaneous mastectomies . at 6.4 years of follow - up , two women who underwent subcutaneous mastectomies developed breast cancer , with one developing metastatic breast cancer in the axilla and the other developing breast cancer in residual breast tissue . in a review of the literature , van verschuer et al .   reported that 21 primary breast cancers occurred after 6,044 prophylactic mastectomies , three occurred after a total mastectomy , and 17 occurred after a conservative mastectomy , but that the majority of primary breast cancers did not originate near nac or skin flap but were found in the chest wall or axilla . they suggested that oncological surgeons should be diligent , ensuring complete removal of all glandular tissue , especially in the axillary tail and chest wall , and that the skin flaps and nac should be dissected as thin as possible . current nsm and ssm techniques aim for skin flaps < 5 mm and for a nac thickness of 2 to 3 mm . ssm and nsm using peri - areolar or inframammary incisions can be challenging , because of difficulty of removal of remaining mammary gland in all quadrants and in the axillary tail . detection of brca1/2 mutations gave rise to a new concept in prophylactic medicine , although risk management for brca1/2 mutation carriers requires further discussion . it is generally accepted that a randomized controlled study design would allow a better evaluation of risk reducing surgery on cancer risk and mortality reduction , it is generally accepted that randomized approach would not be ethical for the management of these patients and therefore , this field of research is limited to undertaking observation studies , which intrinsic methodological limitation . the patient finally described herein chose to undergo bilateral ssm for rrm with the excision of the nipple and preservation of the areola skin . the best choice of risk reduction for brca mutation is different from each others , so it is important that the decision making should be made with knowledge of risk management options , through receiving counseling about the risks and benefits of each options .
women with brca1/2 mutations have a high risk of breast cancer and may opt for risk - reducing mastectomy ( rrm ) . 
 we report a 38-year - old japanese woman who was diagnosed as a brca2 mutation carrier . 
 she underwent prophylactic bilateral skin - sparing mastectomy ( ssm ) with excision of the nipple and preservation of the areola skin . 
 it is unclear whether a bilateral rrm leads to better survival compared with intensive surveillance . 
 the oncological risk associated with the presence of remnant breast glandular tissue after ssm or nipple - sparing mastectomy has been obscure . 
 we report the first case of rrm for a japanese brca mutation carrier and provide a literature review on risk management for brca mutation carriers with a focus on the concepts and procedures of rrm .