Nihon Geka Gakkai zasshi最新文献

Mastectomy and breast-conserving surgery (BCS) are common procedures for treating breast cancer at present. The discovery rate of tumors 2 cm or less in size has risen with the increase in the number of women who receive breast physical examinations, and because of the wider usage of preoperative chemotherapy, BCS has become possible. As a result, the number of women undergoing BCS has increased, whereas the number of those undergoing mastectomy has decreased. However, if radical cure or good cosmetic results cannot be achieved, mastectomy is often offered to patients. Recently, patients have come to expect good cosmetic results after BCS, and because breast reconstruction with implants is now covered by health insurance, it is possible to perform it with mastectomy with the help of plastic surgery if patients desire. Oncoplastic surgery is now the focus of public attention, because it differs from conventional BCS in that it results in no deformity, since the defect created by wide resections is filled with a local tissue flap. It is psychologically important for patients to have satisfactory cosmetic results after BSC.

Breast-conserving therapy was introduced in Japan in the 1980s as a local treatment for early-stage disease used under cautiously developed criteria. Its indications have gradually been expanded by, for example, the addition of concomitant preoperative chemotherapy. More than half of breast cancer patients currently benefit from this treatment. Recently, nonsurgical ablative therapies have been tested as a definitive conservative treatment. Clinical studies on high-intensity focused ultrasound (HIFU) and cryoablation began in 2004 and 2006, respectively. Phase I and phase II multicenter clinical trials of radiofrequency ablation (RFA) as a treatment for early-stage breast cancer were started in 2006 under the Evaluation System of Investigational Medical Care. A prospective phase III trial was started in 2013 under the Advanced Medical Service System. Data on nonsurgical ablative therapies including RFA, cryoablation, and HIFU are steadily accumulating. We believe that these therapies can replace lumpectomy, the current standard treatment for early breast cancer, in the near future.

Breast cancer is the most frequent cancer in Japanese women. As breast density increases, the detection rate of breast cancer by mammography (MMG) decreases. Breast density notification laws have been enacted in several states in the USA. Supplemental screening tools for women with dense breasts are needed. The results of a large randomized trial to compare the sensitivity, specificity, and cancer detection rate of MMG and adjunctive ultrasonography (US) to screen for breast cancer in Japan (J-START) were reported last year. More than 70,000 women aged 40 to 49 years were enrolled. The sensitivity and cancer detection rate were significantly higher in the MMG+US group than in the MMG-alone group. Automated breast ultrasonography is a tool to overcome the operator dependency of hand-held US and low reproducibility. Digital breast tomosynthesis, referred to as 3D MMG, offers higher sensitivity and specificity than MMG. Contrast-enhanced spectral MMG is an MMG scan using contrast medium to detect breast cancer more clearly even in dense breasts. It is often used for women at high risk for cancer and substituted for magnetic resonance imaging. A dedicated breast positron-emission tomography (PET) system has been available in Japan with insurance coverage since 2013. More cases of cancer were detected using breast PET than whole-body PET. Additional studies including mortality rates are needed.

The decision to use adjuvant therapy for breast cancer takes into account tumor biology and tumor stage. Because there have been no effective predictive factors for chemotherapy, current guidelines generally recommend chemotherapy for high-risk breast cancer. Multigene assays may predict the benefit from chemotherapy. With the recognition that estrogen has an important role in the promotion and progression of hormone receptor-positive breast cancer, endocrine therapy is a principle component in the treatment of hormone-sensitive breast cancer. The endocrine treatment of breast cancer utilizes strategies that reduce or halt estrogen production, block signaling through the estrogen receptor (ER), or antagonize the ER itself. Tamoxifen has been recommended for premenopausal women with hormone receptor-positive breast cancer during the past 15 years. The value of adding luteinizing hormone-releasing hormone in premenopausal women who receive tamoxifen should be considered in the high-risk premenopausal cohort. For most women with postmenopausal breast cancer, aromatase inhibitors are recommended. The extension of treatment with endocrine treatment to 10 years could improve the prognosis of hormone receptor-positive breast cancer patients. The benefit of adjuvant trastuzumab was established for human epidermal growth factor type 2-overexpressing breast cancer patients.