The US Preventive Services Task Force (USPSTF) assesses the efficacy of breast cancer screening by the sum of its benefits and harms. Randomized clinical trials (RCTs) of breast cancer screening in Europe and the US have shown 15～32% mortality reduction in the 40～69-year age group. As well as reduction of over-diagnosis, quality control of screening is important for reducing the rates of false positivity, false negativity, and recall. Over-diagnosis in cancer screening has become a hot topic in Europe and the US. 'Over-diagnosis' means the detection and diagnosis of cancers that do not affect the life of the patient. Over-diagnosis is most common during screening for neuroblastoma, prostate cancer, lung cancer and thyroid cancer. Data from Europe and the US indicate that about 10～30% of breast cancers are over-diagnosed by screening. Even in early-stage breast cancer, some lesions, such as non-invasive cancers, can be over-diagnosed. The mammography screening rate in Japan is as low as 20～30%, compared with 70～80% in Europe and the US. In Japan, in addition to emphasizing the harm of screening, it is necessary to improve the participation rate in quality-controlled mammography screening (to 50% or more). In particular, population-based screening should conform to guidelines that are evidence-based for mortality reduction. We also need to perform clinicopathological studies of breast cancers that may be over-diagnosed, and compile data on over-diagnosis. For prevention of over-diagnosis, we need to avoid excessive detailed examinations and over-treatment, and should also consider establishing observation (watchful waiting) groups. There is also a need for joint decision-making between examinees and medical institutions regarding the harm of screening. Treatment of breast cancers that are suspected to be over-diagnosed should be undertaken on the basis of an informed decision by the examinee.

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Visual inspection and palpation in addition to mammography have been performed for breast cancer screening at our health examination facility in Wakayama prefecture, Japan, based on the guidelines of the Ministry of Health, Labour and Welfare. We investigated the significance of visual inspection and palpation in breast cancer screening retrospectively. Between 2204 and 2009, a total of 55,533 women underwent breast cancer screening using mammography, visual inspection and palpation at our institution. The recall rate was 9.6%, the rate of cancer detection was 0.23%, and the positive predictive value was 2.4%. Although the majority of the breast cancers detected by mammography, visual inspection and palpation were at an early stage,including non-invasive (14%) and stage 1 (59%) breast cancer, the detection rates based on visual inspection and palpation were limited to11% for non-invasive breast cancer and 25% for stage１breast cancer. Only one case of cancer was detected by visual inspection and palpation alone (1/55,533). Therefore, it was considered that visual inspection and palpation are of little value for breast cancer screening. We conclude that visual inspection and palpation may not be necessary for breast cancer screening.

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When breast cancer is suspected on the basis of mammography (MMG) or ultrasonography (US), MRI may be requested at neighboring facilities if diagnosis is difficult. However, no standard protocol has yet been established. We therefore conducted a trial to establish an appropriate diagnostic protocol by defining the object standard and examination method for such cases. When it is difficult to perform core needle biopsy (CNB) using US, even though breast cancer is suspected on the basis of MMG or US examination, we apply MRI. We created a MRI protocol (the “Sora-cli protocol”) employing mainly high-resolution scan in the early enhanced phase for the site of breast disease. The breast surgeon and radiologic technologist at our clinic referred to BI-RADS-MRI, evaluated the MRI image together, and determined the subsequent medical strategy. This made it possible to unify the procedure at MRI facilities with the intention of request side. The MRI images suggestive of malignancy in 11 out of 19 cases made into the object appeared. Furthermore, additional study detected 8 cases of breast cancer. Detailed pathological changes can be detected by conducting additional studies when there are signs suggestive of malignancy on MRI, and if no abnormality is evident, subsequent unnecessary additional examinations can be avoided. In addition, it seems that high-resolution scans in the early enhanced phase are excellent for assessment of early breast cancers that have not yet formed tumors. Although variations in medical standards are problematic, it is considered necessary to establish a proper standard and medical organization in order to offer good medical treatment, irrespective of area or environment. Therefore this trial was considered useful.

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Four years have passed since the Japanese government launched a new intensive project to encourage women to undergo breast cancer screening in 2009. In the present study we evaluated the efficacy of the project and the problems associated with it in Kashiwa City. In Kashiwa City as a whole, the proportion of women who underwent screening using a free coupon was, on average, 27.1%. The proportion of women who initially did not aim to undergo screening, but did so because they received a free coupon, was as low as 15.1% on average. At our institution, the number of women who have used the coupon for screening has not increased during the last 4 years. Return screenees, namely women who underwent initial screening because they had received a free coupon and then returned for screening in the following years, were few, indicating no incentive effect of the free coupon to encourage women to undergo successive screenings. One problem we encountered was that too many women visited institutions to undergo screening using the free coupons within a short period before the expiration of the coupon's validity, and not all of them could be accepted. In summary, the intensive project carried out during the past four years does not appear to have significantly encouraged women to undergo breast cancer screening. Further activities aimed at education will be necessary.

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Whereas mammographic density and adiposity are positively associated with postmenopausal breast cancer risk, they are inversely associated with one another. In order to evaluate the relationships of anthropometric adiposity factors, breast cancer risk factors, and serum glucose and lipid levels with mammographic density, we carried out a cross-sectional analysis of healthy postmenoposal women enrolled in the Ebina Health Service Center in 2011, comprising 153 with BI-RADS category I and II density (group LD) and 151 with BI-RADS category III and IV density (group HD). Unvariate analysis, showed that women in the LD group were significantly more obese, with higher levels of TG and lower levels of HDL-C, than those in the HD group (p<0.001, respectively). Multivariate analysis revealed that body weight gain and the level of HDL-C were independently associated with MD after taking into account the possible confounding effects of age and BMI (OR 0.47 95%CI 0.28-0.79 p=0.004, OR 0.50 95%CI 0.28-0.89 p=0.0018, respectively). We conclude that not only anthropometric factors but also body weight gain are important predictors of breast density.

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A case of intraductal papilloma of the breast showing an unusual pattern of calcification on mammography is reported. A 26-year-old woman noticed a right breast mass in the CD area with white nipple discharge and visited our hospital. Nipple discharge cytology was negative. Mammography showed amorphous microcalcifications in a clustered pattern that reflected terminal duct lobular units. Duct ectasia and an intracystic papillary lesion in the CD area were revealed by ultrasonography, and persistent enhancement was revealed by magnetic resonance imaging (MRI). A duct-lobular segmentectomy was therefore performed under a radiological diagnosis of intraductal papilloma. Histologically, the surgically resected lesion was an intraductal papilloma with focal prominent sclerosis, in which numerous microcalcifications were embedded. The calcification was considered to have been derived from condensed secretory material in the small ductules within the papilloma. The walls of the original ductules seemed to be obscured by prominent sclerosis, leaving only calcified material in the sclerosed stroma. The possibility that papilloma may show an unusual pattern of calcification should be borne in mind.

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Tubular carcinoma is a rare carcinoma, accounting for approximately 1% of all breast cancers. Histopathologically, tubular carcinomas are classified into two types: “pure tubular carcinoma” consisting purely of tubular structures, and a “mixed type” that includes other forms of carcinoma. We report a case of tubular carcinoma detected by mammographic screening. The patient was a woman in her early 70s. Physical examination involving inspection and palpation revealed an elastic, firm and irregular tumor, 2 cm in size, in the C region of the right breast. Mammographic findings revealed breakdown of background structures (Category 3). Echography revealed a hypoechoic, irregular tumor, showing decreased posterior echoes at the 10:00 position in the right breast, with vascularity at the periphery of the tumor. No distant metastatic lesions were noted on MRI and CT scans, and no other pathologic findings were evident. An aspiration biopsy yielded no material, and a needle biopsy yielded features suggestive of either scirrhous carcinoma or tubular carcinoma. Resection of the right breast with sentinel lymph node biopsy (Bt+SLNB) was carried out. The sentinel node was negative for cancer metastasis. The pathohistological diagnosis was pure tubular carcinoma (T1N1M0, Stage IIA). Postoperatively the patient received chemotherapy with an aromatase inhibitor for two years. She is currently alive and well without recurrence. Compared with previously reported cases, the present patient was slightly older than usual. Spicule formation, a characteristic mammographic feature of tubular carcinoma, was not evident in this case, but other findings such as lack of tumor formation or calcification were typical. Echography in this case yielded no findings specific for tubular carcinoma, but strongly suggested the presence of cancer.

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Apocrine carcinoma of the breast is rare, accounting for 0.5-2.0% of all breast cancers. We experienced a case detected by ultrasonographic screening. A woman in her late５０s presented with a movable, elastic firm tumor, 5 mm in size, in the C region of the left breast. Echographic examination detected a flat and lobulated tumor, 24×29×6 mm in size, at the 1:00-2:00 position in the left breast, which was outlined relatively clearly and showed rich vascularity within the tumor. Punctate high-echoic spots suggesting the presence of minute calcified deposits were evident. Mammography showed breakdown of background structure in the left U area. There were no signs of distant metestasis on MRI and CT scans. Quadrantectomy and sentinel node biopsy were performed, and the node was negative for metastasis. The final pathologic diagnosis was apocrine carcinoma of the breast. Postoperatively the patient received chemotherapy and irradiation of the remnant breast, and two years after the operation, she is alive without cancer recurrence. As mammographic and echographic findings characteristic for apocrine carcinoma have not been determined, this case did not present any specific findings. In this case, the associated mastopathy predominated, and may have masked any specific mammographic or echographic findings. Echographic findings in this case were somewhat unusual, i.e. the tumor appeared flat with an almost clear outline, simulating a benign tumor. Pleomorphism in mammographic and echographic scans of apocrine carcinoma may be pathohistological in origin, or associated with mammary tissue abnormalities.

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