Mammographic screening in Japan has been established since 2000. Even though the participation rate remains low（around 30%）, it is necessary to assess the results― in terms of benefits and harm ― in order to determine whether or not our screening method is effective. We sought to compare the molecular characteristics of screen―detected vs. symptomatic breast cancers and assess whether differences in tumor biology might translate into survival benefit. Only the luminal A subtype was more common in the screened group. Tumor size and negativity for axillar lymph node metastasis were more favorable for screen―detected than for symptomatic cancers. The immunohistological MIB―1 index was the same for all subtypes, irrespective of whether they had been screened or unscreened. Accordingly, breast cancer screening does not appear to be uniformly effective because it depicts only slow―growing breast cancers, but not aggressive cancers such as triple―negative and HER2―positive tumors. Further studies are warranted to reinterpret the efficacy of screening in the light of tumor biology.
The subtype of breast cancer is an important factor affecting subsequent mortality. Non―luminal breast cancer has been considered to have high―grade malignancy. The purpose of this study was to clarify the subtype of breast cancer detected by ultrasound（US）and mammography（MG）screening. Screening using US and MG was performed for ２８，６９１ and ４０，２８２ women, respectively, between January ２００９ and December ２０１１ at our preventive medicine center. Cancers were detected in １１２（０．３９％, １２４ lesions）and ９７（０．２４％, １０１ lesions）women by US and MG, respectively. We investigated the subtypes of ７４ US―detected invasive cancers and ５９ MG―detected invasive cancers, and the following results were obtained: US: Luminal A（LA）２５ （３３．８％）, Luminal B（LB）３８（５１．４％）, LA/B６（８．１％）, HER２２（２．７％）, and triple negative （TN）３（４．１％）. MG: LA１３（２２．０％）, LB３２（５４．２％）, LA/B３（５．１％）, HER２６（１０．２％）, TN４（６．８％）, and HER２／TN１（１．７％）. In our series luminal cancers were detected more often overall by US than by MG（p＜０．００１）. Thirty―seven cancers were detected among １１９３８ subjects, who underwent both MG and US. Only three non―luminal cancers were detected; all of them were detected by MG and none was detected by US alone. Although US is effective for detecting MG―negative breast cancer in dense breasts, our results suggest that additional US is of limited utility for detecting non―luminal cancer with a high grade of malignancy.
Focal asymmetric densities（FADs）are classed as category １ when ultrasonography allows an observer to conclude they fall within the range of normal variation according to the criteria for combined screening with mammography and ultrasonography. However, the detectability of FAD by ultrasonography has not been studied systematically. In this study, we considered the combined criteria that would increase the specificity of breast cancer screening using mammography and ultrasonography for FADs that necessitated recall after mammography screening. We analyzed １４１ breasts with FAD, identified from a database of mammographic reports for ４４５ patients who had been recalled after mammography screening in ２０１１. Among these cases we reconfirmed ９４ showing FAD. Ultrasonography was able to detect ６８％ of these FAD cases, and ３１％ were considered to represent normal variation（overlapping or isolated mammary gland）. Ultrasonography was unable to detect ３２％ of cases in which breast cancers had not been diagnosed. Eight breast cancers were diagnosed among our FAD cases; six were invasive and the median size of the mammographic FAD was ２３（１７―４３）mm, whereas the sizes of the tumors determined on the basis of ultrasonography and pathology were２２（１４―３５）and３１（１２―５６）mm, respectively. One was categorized as category ３ and the others as category ４―５ on ultrasonography. Ultrasonographic detection of breast cancers from FADs recalled after mammography screening may be relatively easy when the cancers are large or invasive. FADs may also be classed as category１ by synchronous combined screening when the corresponding lesion cannot be detected by ultrasonography. Further research is needed to find better ways of detecting elusive breast cancers with some kind of background mammary gland on ultrasonography.
Stereotactic vacuum―assisted biopsy（Mammotome, ST―MMT）provides accurate diagnosis of breast cancer. Here we discuss the accuracy of the initial results we have obtained with the ST―MMT procedure in comparison with either re―biopsy or surgical resection.
A total of２６４ST―MMT procedures conducted from February ２００９ through April ２０１３were reviewed retrospectively. Among the cases examined, １７２ were diagnosed as benign. During follow―up, six cases showed the change in the distribution of microcalcification, and re―biopsy was performed using ST―MMT. Although two of them were atypical papillary lesion or atypical ductal hyperplasia, none of the cases were diagnosed as breast cancer. In ２２ cases, atypical epithelium was found, and more careful follow―up was requested. Two years after initial biopsy, ductal carcinoma in situ was detected in one case.
Seventy patients diagnosed as having malignant lesions underwent surgery at our hospital, and in ８７％ of them the ST―MMT result was found to be concordant with the final histology obtained at surgery. Nine cases that were diagnosed as ductal carcinoma in situ from the ST― MMT specimen were finally diagnosed as invasive carcinoma after surgery.
ST―MMT is diagnostically reliable for microcalcifications in the breast. Although the procedure may be invasive, it is advantageous to patients in terms of safety and accuracy.
Radiological technicians play an important role in operating the stereotactic vacuum―assisted Mammotome（STMMT）for detection of calcified breast lesions. At our institution, radiological technicians have been required to write technical reports to share information about the process and the results of clinical examination. Five clinicians explain the necessity of STMMT to the patients, and two other clinicians actually operate the STMMT with the assistance of the technicians. The technicians’ reports include details of how the biopsy had been carried out and whether calcification was adequately detected. A total of４７９patients underwent STMMT between February ２００９ and September ２０１３, and the reports were reviewed and evaluated for their usefulness.
All ７ clinicians recognized the usefulness of these reports for gaining information about the correspondence between radiological findings and pathological reports, and for management of patient unease and dissatisfaction with regard to STMMT. The technicians’ reports were also useful for determining the size of the specimen to be surgically excised. In this way, the technical reports were proved to be useful for clinical diagnosis and surgical treatment. As radiological technicians are responsible for operating the STMMT, their technical reports are helpful for confirming the reliability of the procedure and for promoting the quality of medical care.