Neoadjuvant systemic therapy in invasive lobular breast cancer: Is it indicated?

BACKGROUND: This study investigated patients with invasive lobular breast carcinoma (ILC) to determine the benefit of neoadjuvant systemic therapy (NAST). METHODS: Patients with ILC treated from 2006 to 2015 were identified. Tumor characteristics and treatment data were analyzed. RESULTS: Of the 560 patients with ILC, 77 patients received NAST. Patients who received NAST presented with larger clinical T stages compared to patients who received surgery first (p < 0.001). Pathological complete response (pCR) to NAST was seen in 17% of patients. Only 14% of patients with clinically positive lymph nodes downstaged to N0. These patients were more likely to have HER2 positive tumors (p < 0.029) and larger tumor size at diagnosis (p < 0.015). Mastectomy was performed in 84% of patients and lumpectomy in 16%. CONCLUSIONS: Only a minority of patients with ILC achieve pCR. The majority of patients still undergo mastectomy; therefore the benefit of NAST in ILC appears limited.

Association of tamoxifen use and ovarian function in patients with invasive or pre-invasive breast cancer.

The impact of long-term tamoxifen therapy on ovarian function is not known. Understanding these effects will help reproductive-aged patients who desire future pregnancy make more informed decisions regarding their treatment. This is a retrospective cohort study in patients identified through the UCSF Cancer Registry and SPORE database. We enrolled women with a history of ductal carcinoma in situ (DCIS) or early stage invasive breast cancer who were premenopausal at diagnosis and did not receive chemotherapy. Menstrual histories were obtained through electronic and paper surveys. We compared the age of menopause onset and menstrual pattern changes between women who received tamoxifen (TAM) and those who did not receive tamoxifen (control). Neither group received chemotherapy. 250 subjects were included in this study (125 TAM, 125 control). Mean age of menopause onset was 51.0 for both the groups and was not associated with duration of tamoxifen use or the age at tamoxifen initiation. Menstrual pattern changes, including amenorrhea, were more frequent in the TAM group than control group (any change: 48% TAM vs. 15 % control, p < 0.001; amenorrhea: 22% TAM vs. 3% control, p < 0.001). Older age was associated with an increased risk of developing amenorrhea within 6 months of starting tamoxifen (HR 1.32, p < 0.001). Menstrual pattern changes are common in premenopausal women taking tamoxifen. Tamoxifen use in the absence of chemotherapy is not associated with an earlier age onset of menopause in patients with DCIS or invasive breast cancer and is unlikely to significantly accelerate ovarian aging.

Genome-wide association study of breast cancer in Latinas identifies novel protective variants on 6q25.

The genetic contributions to breast cancer development among Latinas are not well understood. Here we carry out a genome-wide association study of breast cancer in Latinas and identify a genome-wide significant risk variant, located 5' of the Estrogen Receptor 1 gene (ESR1; 6q25 region). The minor allele for this variant is strongly protective (rs140068132: odds ratio (OR) 0.60, 95% confidence interval (CI) 0.53-0.67, P=9 × 10(-18)), originates from Indigenous Americans and is uncorrelated with previously reported risk variants at 6q25. The association is stronger for oestrogen receptor-negative disease (OR 0.34, 95% CI 0.21-0.54) than oestrogen receptor-positive disease (OR 0.63, 95% CI 0.49-0.80; P heterogeneity=0.01) and is also associated with mammographic breast density, a strong risk factor for breast cancer (P=0.001). rs140068132 is located within several transcription factor-binding sites and electrophoretic mobility shift assays with MCF-7 nuclear protein demonstrate differential binding of the G/A alleles at this locus. These results highlight the importance of conducting research in diverse populations.

Polarized deposition of basement membrane proteins depends on Phosphatidylinositol synthase and the levels of Phosphatidylinositol 4,5-bisphosphate.

The basement membrane (BM), a specialized sheet of the extracellular matrix contacting the basal side of epithelial tissues, plays an important role in the control of the polarized structure of epithelial cells. However, little is known about how BM proteins themselves achieve a polarized distribution. Here, we identify phosphatidylinositol 4,5-bisphosphate (PIP2) as a critical regulator of the polarized secretion of BM proteins. A decrease of PIP2 levels, in particular through mutations in Phosphatidylinositol synthase (Pis) and other members of the phosphoinositide pathway, leads to the aberrant accumulation of BM components at the apical side of the cell without primarily affecting the distribution of apical and basolateral polarity proteins. In addition, PIP2 controls the apical and lateral localization of Crag (Calmodulin-binding protein related to a Rab3 GDP/GTP exchange protein), a factor specifically required to prevent aberrant apical secretion of BM. We propose that PIP2, through the control of Crag's subcellular localization, restricts the secretion of BM proteins to the basal side.