With the aim of formulating an official standard of quality assurance, a questionnaire study of quality assurance for breast cancer screening by ultrasound examination was carried out, focusing on applicants for the 2010 training courses sponsored by the Japan Association of Breast and Thyroid Sonology. The training courses for technicians were carried out ６times in 2010.The questionnaires were compiled by the Quality Assurance Subcommittee, sent to all applicants before the training courses, and collected afterwards. The respondents belonged to169 institutions, of which two common kinds were noted, one type having 1,000 to 5,000 screening examinee and the other having 100 to 500 respondents. At many institutions, 5 or fewer examiners performed examinations. At institutions where there were many examiners, most were technicians. The time required for one examination was 8.7 min on average, and the time taken from entering the room until leaving was 12.7 minutes. Comparison with the previous examinations was performed in 84% of the respondents. In 79% of the institutions the pictures were stored in electrical recording systems. Confirmation of the results at the referring hospitals was carried out in only 30% of the respondents. The present results indicate the importance of quality control for technicians who perform ultrasound examinations and also the doctors who evaluate the pictures. Standardization of both the ultrasound examination procedure and decision of the results is also imperative.

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In the breast cancer screening program adopted by our hospital's Health Care Center as part of a comprehensive medical check-up, mammography (MMG) is performed in addition to a clinical breast examination to provide better screening quality. The clinical breast examination is performed by our surgeons. Two-view MMG is performed for women in their 40's and one-view MMG for the others. If any abnormality is detected in the clinical breast examination, or if MMG reveals abnormalities of category 3 or over, a more thorough diagnostic work-up is recommended. Each year, 1,400 or more women undergo breast cancer screening at the center, with an average recall rate of 12% and an average breast cancer detection rate of 0.14%. The high recall rate indicates the need for improvement of screening accuracy. Although the breast cancer detection rate and positive predictive value are somewhat low, the majority of the detected cases are early-stage breast cancer, thus demonstrating the efficacy of the screening. Herein, we describe the current state of MMG screening in our comprehensive medical check-up, along with a discussion of the screening procedure. However, further efforts are needed to improve screening accuracy.

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After partial mastectomy, adhesion and fixation occur between the excised areas and the surrounding structures, preventing good exposure of some parts of the remnant breast tissue at mammography. We examined mammograms taken in 2010 of 24 post-partial mastectomy patients who showed adhesion in the C-area. Seven of these patients had undergone additional axillary lymph node dissection. We found that post-partial mastectomy adhesion and fixation to the surrounding tissues were variable in individual patients, and that axillary dissection had extended the adhesion further. For obtaining good mammograms in these patients, it was important firstly to clarify the sites and grade of adhesion and fixation caused by the previous surgery, and secondly to modify the patient's positioning at the time of mammography by fully extending the movable tissues,bringing them close to the fixed site, and applying pressure on them. In this way, radiological technicians must modify the positioning of post-partial mastectomy patients after careful reference to the surgical procedure performed and the sites of adhesion and fixation.

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The risk of radiation exposure associated with mammography in breast cancer screening must be considered. In this study, we re-evaluated the benefit vs. risk of the mammographic procedure used for breast cancer screening in Japan, assuming a screening interval of 2 years with 2 mammography views for women aged 40-49 years and１view for those aged 50 years or more. We also used a new breast tissue weighting factor defined by ICRP 2007 and the life-time mortality coefficient defined by BEIR. The effective radiation dose used in mammography was assumed to be 0.72 mSv and 0.36 Sv for women aged 40-49 and 50 years or more respectively. The risk was expressed as loss of life expectancy (person-day) due to a single screening test. On the other hand, the benefit of screening was calculated on the basis of the number of lives saved by a stage shift of breast cancer detected by screening and then multiplying by the average life expectancy. Thus the benefit was expressed as the gain of life expectancy (person-day) due to a single screening. Finally, the benefit/risk ratio was obtained as: gain of life expectancy/loss of life expectancy as a function of age at which the benefit/risk ratio exceeded 1.0. In this study we showed that the benefit/risk ratio exceeds 1.0 from age of 25 years old or more in Japanese breast cancer screening, and so our screening is justified because the lowest age for the screenee is set at 40 years old.

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Stereotactic mammotome biopsy (mammotome) allows distinction between benign and malignant breast lesions on the basis of tumor spread. With the spread of screening mammography,mammotome biopsy has become more common. Between November 2006 and December 2008, stereotactic mammotome biopsies were performed for 134 microcalcificated lesions revealed by mammography. This report describes comparative analysis of category classification on the basis of detection opportunity and pathological findings. The series we describe included 72 patients who underwent mammography for medical examinations, 16 who underwent mammography performed by the same clinician who had examined the patient previously, 12 who underwent follow-up for microcalcifications, 10 who underwent preoperative mammography, 4 who underwent postoperative follow-up mammography, and 18 others, giving a total of 132 cases. Category (C) classification included C-2: 36 cases (27%), C-3: 49 cases (37%), C-4: 44 cases (33%), and C-5: 3 cases (2%). Among the 72 patients who underwent medical examination mammography, 15 had C-2 lesions,and all of them were benign. The C-2 in the microcalcification made checked by the medical examination MMG was benignancy, and thought to avoid excessive inspection. On the other hand, because the diagnosis of breast disease is difficult, we think that the mammotome examination on an ambulatory basis is useful for definitive diagnosis.

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Needle biopsy under ultrasonographic guidance is being used increasingly to provide specimens for pathological diagnosis of breast lesions. The advantage of this technique is that it is less invasive, easy and economical to perform, and does not deform the shape of the breast in comparison with conventional surgical biopsy. We analyzed 127cases of needle biopsy performed for intracystic tumors of the breast, including 10 cases of core needle biopsy (CNB) and 117 cases of vacuum-assisted biopsy (VAB). The pathological diagnosis of the biopsy specimens was malignant in 18, benign in 96 and intermediate in 13. Surgical removal of the tumor was performed in 41 women who underwent needle biopsy. Pathological examination of the surgically resected specimens demonstrated malignancy in 30 intracystic tumors (30/127). In this series, there were no false-positive cases, and the sensitivity was 60%. We conclude that needle biopsy is useful for the diagnosis of malignancy in intracystic tumors of the breast. VAB in particular can provide larger biopsy specimens containing part of the cystic wall of the tumor, allowing greater confidence when diagnosing malignancy.

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We have been performing stereotactic mammotome biopsy by the upright method. However, we have only one mammographic unit. Therefore, it cannot be confirmed whether calcification is included in the specimen at the time of biopsy. Therefore we devised a support tool to confirm the specimen location using the mammographic unit. This support tool uses the radiation aperture of the mammographic unit and the space of the breast. It also has a hand-made lead shield (rectangular tube) to shield the patient from X-ray leakage. The results obtained using this support tool are similar to those obtained by enlarging radiography with soft X-ray. In addition, the support tool is economical because it can be used in an existing environment, and enables confirmation that the calcification is included in the specimen. No X-ray leakage from the support tool was detectable, suggesting that the patient was not exposed to radiation. In addition, it was found that the type of FCR reading device was not influenced by the presence of the calcification in the specimen. Therefore, it is thought that combination of a general FCR reading device with the support tool is feasible, and that the tool can become an efficient modality if it can be configured to the type of examination employed. However, as the tool needs to be detached in front of the patient, it seems necessary to limit its use in order to minimize the burden on the patient.

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The minimum size of breast cancer detectable by mammography is theoretically 5mm. If a 5-mm cancer fails to be detected by screening mammography and then grows to 2cm in the next 2 years, the tumor doubling time (DT) is calculated to be 120 days. In 30 patients with breast cancer (21 with mammographically detected tumors and 9 with calcified lesions), the DT was determined by measuring the sizes of the tumors evident on the previous mammograms. If a breast cancer has a DT of less than 120 days, and the screening interval is 2 years, the cancer will have become large and associated with lymph node metastasis. We determined the histopathological type, hormone receptors (HR) and Her2, and studied their relationships with DT. Breast cancers with a DT of less than 120 days were found in 43% of patients with tumors (9/21) and 44% of patients with calcified lesions (4/9). When analyzed according to subtype, 3 cases involving HR (-) and Her 2 (-) tumors showed a very short DT of about 60 days, and 2 of them showed metaplasia pathologically. Cases involving HR (-) and Her2 (+) cancers and those with HR (+) and Her2 (+) cancers showed a DT of 112±10 days and 128±days, respectively. Nineteen cases involving HR (+) Her2 (-) cancers had widely variable DTs of 867±679 days. Among them, 5 (26%) showed a DT less than 120 days, and the pathological types were mucinous cancer in 3 cases and common type of cancer in 2. In conclusion, although a screening interval of 2 years appears to be reasonable for patients with HR (+) and Her2 (-) cancers, a shorter interval is necessary for those with HR (-) and Her2 (-) cancers or Her2 (+) cancers.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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