SummaryTo correlate the variable clinical features of estrogen receptor positive (ER+) breast cancer with somatic alterations, we studied pre-treatment tumour biopsies accrued from patients in a study of neoadjuvant aromatase inhibitor (AI) therapy by massively parallel sequencing and analysis. Eighteen significantly mutated genes were identified, including five genes (RUNX1, CBFB, MYH9, MLL3 and SF3B1) previously linked to hematopoietic disorders. Mutant MAP3K1 was associated with Luminal A status, low grade histology and low proliferation rates whereas mutant TP53 associated with the opposite pattern. Moreover, mutant GATA3 correlated with suppression of proliferation upon AI treatment. Pathway analysis demonstrated mutations in MAP2K4, a MAP3K1 substrate, produced similar perturbations as MAP3K1 loss. Distinct phenotypes in ER+ breast cancer are associated with specific patterns of somatic mutations that map into cellular pathways linked to tumor biology but most recurrent mutations are relatively infrequent. Prospective clinical trials based on these findings will require comprehensive genome sequencing.

Background We investigated differences in breast cancer mortality between younger (<40 yrs) and older (≥40 yrs) women by stage at diagnosis to identify patient and tumor characteristics accounting for disparities. Study Design We conducted a retrospective study of women diagnosed with breast cancer in the 1988-2003 Surveillance, Epidemiology, and End Results (SEER) Program data. Multivariate Cox regression models calculated adjusted hazard ratios (aHR) and 95% confidence intervals (CI) to compare overall and stage-specific breast cancer mortality in women <40 yrs and women ≥40 yrs, controlling for potential confounding variables identified in univariate tests. Results Of 243,012 breast cancer patients, 6.4% were <40 yrs, while 93.6% were ≥40 yrs. Compared with older women, younger women were more likely to be Black, single, diagnosed at later stages, and treated by mastectomy. Younger women had tumors that were more likely to be higher grade, larger size, ER/PR negative, and lymph-node positive (p<0.001). Younger women were more likely to die from breast cancer compared with older women (cHR 1.39, CI 1.34-1.45). Controlling for confounders, younger women were more likely to die compared with older women if diagnosed with Stage I (aHR 1.44, CI 1.27-1.64) or Stage II (aHR 1.09, CI 1.03-1.15) disease and less likely to die if diagnosed with Stage IV disease (aHR 0.85, CI 0.76-0.95). Conclusions Higher breast cancer mortality in younger women was attributed to poorer outcomes with early stage disease. Further studies should focus on specific tumor biology contributing to the increased mortality of younger women with early stage breast cancer.

Purpose Cyclin-dependent kinase (CDK) 4/6 drives cell proliferation in estrogen receptor positive (ER+) breast cancer. This single-arm phase II neoadjuvant trial (NeoPalAna) assessed the anti-proliferative activity of the CDK4/6 inhibitor palbociclib in primary breast cancer as a prelude to adjuvant studies. Experimental Design Eligible patients with clinical stage II/III ER+/HER2- breast cancer received anastrozole 1mg daily for 4 weeks (cycle 0) (with goserelin if premenopausal), followed by adding palbociclib (125mg daily on days 1-21) on cycle 1 day 1 (C1D1) for four 28-day cycles unless C1D15 Ki67>10%, in which case patients went off study due to inadequately response. Anastrozole was continued until surgery, which occurred 3-5 weeks post palbociclib exposure. Later patients received additional 10-12 days of palbociclib (Cycle 5) immediately before surgery. Serial biopsies at baseline, C1D1, C1D15, and surgery were analyzed for Ki67, gene expression and mutation profiles. The primary endpoint was Complete Cell Cycle Arrest (CCCA: central Ki67<2.7%). Results Fifty patients enrolled. The CCCA rate was significantly higher after adding palbociclib to anastrozole (C1D15 87% vs C1D1 26%, p<0.001). Palbociclib enhanced cell cycle control over anastrozole monotherapy regardless of luminal subtype (A vs B) and PIK3CA status with activity observed across a broad range of clinicopathological and mutation profiles. Ki67 recovery at surgery following palbociclib washout was suppressed by cycle 5 palbociclib. Resistance was associated with non-luminal subtypes and persistent E2F-target gene expression. Conclusions Palbociclib is an active anti-proliferative agent for early-stage breast cancer resistant to anastrozole, however, prolonged administration may be necessary to maintain its effect.

Analysis of the 1988-2003 SEER data indicated that extirpation of the primary breast tumor in patients with stage IV disease was associated with a marked reduction in risk of dying after controlling for variables associated with survival.

Purpose:To evaluate in vivo sentinel lymph node (SLN) mapping by using photoacoustic and ultrasonographic (US) imaging with a modifi ed clinical US imaging system. Materials and Methods:Animal protocols were approved by the Animal Studies Committee. Methylene blue dye accumulation in axillary lymph nodes of seven healthy Sprague-Dawley rats was imaged by using a photoacoustic imaging system adapted from a clinical US imaging system. To investigate clinical translation, the imaging depth was extended up to 2.5 cm by adding chicken or turkey breast on top of the rat skin surface. Three-dimensional photoacoustic images were acquired by mechanically scanning the US transducer and light delivery fi ber bundle along the elevational direction. Results:Photoacoustic images of rat SLNs clearly help visualization of methylene blue accumulation, whereas coregistered photoacoustic/US images depict lymph node positions relative to surrounding anatomy. Twenty minutes following methylene blue injection, photoacoustic signals from SLN regions increased nearly 33-fold from baseline signals in preinjection images, and mean contrast between SLNs and background tissue was 76.0 6 23.7 (standard deviation). Methylene blue accumulation in SLNs was confi rmed photoacoustically by using the optical absorption spectrum of the dye. Three-dimensional photoacoustic images demonstrate dynamic accumulation of methylene blue in SLNs after traveling through lymph vessels. Conclusion:In vivo photoacoustic and US mapping of SLNs was successfully demonstrated with a modifi ed clinical US scanner. These results raise confi dence that photoacoustic and US imaging can be used clinically for accurate, noninvasive imaging of SLNs for axillary lymph node staging in breast cancer patients.q RSNA, 2010