re: For debate: Post-treatment mammography following breast-conserving treatment

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Borderline breast core needle histology: predictive values for malignancy in lesions of uncertain malignant potential (B3)

Breast core needle biopsy (CNB) is an accurate test but may result in borderline histology (lesions of uncertain malignant potential or B3). This is an evaluation of the largest series (to date) of B3 histology, which focusses on estimating positive predictive values (PPV) for malignancy. We identified all B3 CNBs over a 10-year period in a single institution (N=372) from a series of 4035 consecutive needle biopsies. We describe the imaging findings, and report excision histology outcomes (N=279) and category-specific PPV for B3 lesions using two approaches including estimates based on subjects who had either excision or follow-up (N=328). B3 represented 9.2% of all CNB results. Excision histology was benign in 181 (64.9%) and malignant in 98 (35.1%) subjects (61 ductal carcinoma in situ, 37 invasive carcinoma). Positive predictive value for malignancy (based on excision histology) was 35.1% (95% CI: 29.5–40.7) and PPV (based on excision or review) was 29.9% (95% CI: 24.9–34.8). Lesion-specific PPV (estimates in parentheses for excision or follow-up) was atypical ductal hyperplasia 44.7% (40.6%); lobular intraepithelial neoplasia 60.9% (58.3%); papillary lesion 22.7% (15.9%); radial scar 16.7% (12.3%); phyllodes tumour 12.5% (12.5%); and B3 not specified 20.0%. Approximately one-third of CNB results classified as B3 are malignant on excision, and the likelihood of malignancy varies substantially between specific lesion groups. Whereas cases may be selectively managed without surgery, the majority warrant excision biopsy based on our estimates. Research is needed to improve differentiation between malignant and benign diseases in B3 lesions using diagnostic or predictive methods

The overdiagnosis nightmare: a time for caution

Overdiagnosis (and overtreatment) of cancers not bound to become symptomatic during lifetime is an unavoidable drawback of mammography screening. The magnitude of overdiagnosis has been estimated to be in the range of 5-10%, and thus acceptable in view of screening benefits as to reduced mortality. In a recent research article in BMC Women's Health, Jørgensen, Zahl and Gøtzsche suggest that overdiagnosis may be as high as 33%, based on their analysis of breast cancer incidence in screened and non-screened areas in Denmark. Here we consider how reliable such analyses can be, why it might have been useful to adjust comparisons between screened and non-screened areas for early detection lead time, and what further evidence might be needed to build on or confirm these results

Early prediction of pathologic response to neoadjuvant therapy in breast cancer: Systematic review of the accuracy of MRI

Abstract Magnetic resonance imaging (MRI) has been proposed to have a role in predicting final pathologic response when undertaken early during neoadjuvant chemotherapy (NAC) in breast cancer. This paper examines the evidence for MRI's accuracy in early response prediction. A systematic literature search (to February 2011) was performed to identify studies reporting the accuracy of MRI during NAC in predicting pathologic response, including searches of MEDLINE, PREMEDLINE, EMBASE, and Cochrane databases. 13 studies were eligible (total 605 subjects, range 16–188). Dynamic contrast-enhanced (DCE) MRI was typically performed after 1–2 cycles of anthracycline-based or anthracycline/taxane-based NAC, and compared to a pre-NAC baseline scan. MRI parameters measured included changes in uni- or bidimensional tumour size, three-dimensional volume, quantitative dynamic contrast measurements (volume transfer constant [Ktrans], exchange rate constant [ k ep ], early contrast uptake [ECU]), and descriptive patterns of tumour reduction. Thresholds for identifying response varied across studies. Definitions of response included pathologic complete response (pCR), near-pCR, and residual tumour with evidence of NAC effect (range of response 0–58%). Heterogeneity across MRI parameters and the outcome definition precluded statistical meta-analysis. Based on descriptive presentation of the data, sensitivity/specificity pairs for prediction of pathologic response were highest in studies measuring reductions in Ktrans (near-pCR), ECU (pCR, but not near-pCR) and tumour volume (pCR or near-pCR), at high thresholds (typically >50%); lower sensitivity/specificity pairs were evident in studies measuring reductions in uni- or bidimensional tumour size. However, limitations in study methodology and data reporting preclude definitive conclusions. Methods proposed to address these limitations include: statistical comparison between MRI parameters, and MRI vs other tests (particularly ultrasound and clinical examination); standardising MRI thresholds and pCR definitions; and reporting changes in NAC based on test results. Further studies adopting these methods are warranted

Surveillance for endometrial cancer with transvaginal ultrasonography of breast cancer patients under tamoxifen treatment

The association of endometrial thickness with the risk of developing endometrial cancer (EC) within 2 years was investigated in a consecutive cohort of 1205 breast cancer patients under tamoxifen treatment, undergoing transvaginal ultrasonography (TVUS) for follow-up purpose (asymptomatic, 1068) or for abnormal uterine bleeding (AUB, 137). Linkage with tumour registry allowed for the follow-up of 3184.3 person-years. According to underlying incidence, 1.85 EC cases were expected in the study cohort while 12 were observed (observed/expected ratio=6.49, 95% CI 3.35–11.33; asymptomatic=4.09, 95% CI 1.65–8.43, symptomatic=35.71, 95% CI 11.59–83.34). No EC was observed with thickness (half layer) <3 mm. Raising this threshold increased specificity with a substantial loss of sensitivity (⩾3, ⩾4, ⩾6, ⩾9 mm; spec.=25.8, 44.5, 76.1, 91.5%, sens.=100, 91.6, 75.0, 66.6%). The presence of AUB was rather specific (88.94%) but poorly sensitive (41.67%). A combination of AUB presence/absence and thickness allowed the best accuracy (AUB + thickness ⩾3, ⩾4 or ⩾5; sens.=100, 81.6 or 91.6%; spec.=22.8, 40.4, or 56.7%). Breast cancer patients under tamoxifen might be selected for further invasive assessment on the basis of AUB and endometrial thickness assessed at TVUS