Background: Numerous epidemiological and pre-clinical studies have associated potential antineoplastic activity with the antidiabetic drug metformin in various tumor types including breast cancer (BC). We are conducting a neoadjuvant “window of opportunity” study to examine biologic and clinical effects of metformin in early stage BC. Data from a planned interim analysis are presented here. Materials and methods: 15 of planned 40 non-diabetic women < 75 yo with newly diagnosed untreated BC were given metformin 500 mg tid for ≥2 weeks post diagnostic core biopsy until definitive surgery. Fasting blood and tumor tissue were obtained, anthropometric measurements performed and the EORTC QLQ C-30 administered pre-metformin and on the day of surgery. Clinical (weight, symptoms, EORTC QLQ C-30) and biologic characteristics were compared pre-metformin and at the end of metformin treatment as were Ki67 (our primary end-point), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), cleaved caspase 3, physiologic markers (insulin, HOMA,TNF-alpha) and molecular markers [phosphorylated 4E-BP1, phosphorylated protein kinase B (P-PKB/Akt), phosphorylated AMPK (P-AMPK), insulin receptor(IR), Insulin-like growth factor 1 receptor(IGF-1R)]. Analysis of Ki67, cleaved Caspase 3 and TUNNEL were performed on a blinded fashion. Ki-67 was scored by manual count selected by and expressed as percentage of cells with positive nuclear staining. Results: Mean age was 51.7 years. 73.3% (11/15) and 26.7% (4/15) had T1 and T2 BC respectively; 40% (6/15) were node positive, 86.7% (13/15) were ER and PR positive and 26.6% (4/15) were HER-2 +. Metformin was administered for a median of 21 days (range 14 - 40). Gastrointestinal (GI) side effects were most frequent and usually self-limiting — mild diarrhoea 60% (9/15), anorexia 53% (8/15) and nausea 46% (7/15). EORTC30 QLQ scores were stable. Weight decreased (mean change -0.81 kg; Mann-Whitney U p-value 0.057). HOMA (a marker of insulin sensitivity) and C-reactive protein improved, mean change -0.32 and -0.21mg/L respectively. Ki67 decreased significantly after metformin treatment (from 27.6 to 22.7, Wilcoxon signed-rank test p-value = 0.043); TUNEL staining increased significantly (from 0.43 to 1.48, p=0.03) and cleaved Caspase 3 increased non-significantly (from 1.01 to 3.96, p=0.31). Conclusion: Preoperative metformin was well tolerated with mild GI toxicities, but no significant QOL effects; it was associated with improved insulin resistance. A short term administration of metformin significantly reduced breast cancer cell proliferation (as measured by change in Ki67 index) and induced apoptosis (reflected by TUNEL). Metformin administration elicited potential physiologic and cellular effects in breast cancer that are in keeping with beneficial anti-cancer effects. Updated results and the impact of metformin on IR/IGF1R/PI3K and AMPK/mTOR signaling pathways within the cancers will be reported. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD03-06.

Background: Vitamin D (Vit D) supplementation is an area of interest in the primary and secondary prevention of many cancers. We previously reported a high prevalence of Vit D insufficiency and deficiency in newly diagnosed breast cancer (BC) patients. Low Vit D levels were associated with poor BC outcomes. Here we evaluate the state of Vit D adequacy and supplementation in a more recently diagnosed cohort of BC patients from 2 large urban centres, and we examine the feasibility of a placebo-controlled randomized trial (RCT) of supplementation in this population. Patients and Methods: Women diagnosed with T1-3, N0-3, M0 invasive BC within the previous 2 years were prospectively identified from institutional registries and recruited from Mount Sinai Hospital, Toronto and UCLA, Los Angeles (LA), between March 2009 and January 2010. Anthropometric measurements were performed, and dietary, lifestyle and medication histories were obtained using structured questionnaires and interviews. Tumor and treatment characteristics were obtained from clinical records; blood samples were collected for analysis of Vit D levels. The pre-specified feasibility criteria for a Vit D (vs placebo) RCT were: ≥30% of patients with (i) deficient or insufficient Vit D levels, (ii) taking ≥1000 IU Vit D/day and (iii) willing to participate in such a trial. Results: 173 eligible patients were enrolled (80 Toronto, 93 LA). Median age at enrollment was 57 years; 73.4% were post-menopausal. Median tumor size (1.8 cm), lymph node involvement (39%), ER (80%), PR (65%) and Her2 (15%) positivity were similar between centres. Treatment characteristics including rates of mastectomy (44%), adjuvant chemotherapy (56%), radiation (68%), hormonal therapy (69%) and trastuzumab (14%) did not differ between centres. 84.4% of women reported use of Vit D containing supplements, with median daily doses of 1200 IU (Toronto) and 1400 IU (LA) (p=0.3) among users. Respective median 25-OH Vit D levels were 85.5 nmol/L (34.3 ng/mL) and 98.5 nmol/L (39.5 ng/mL) (p=0.04), and rates of deficiency, insufficiency and adequacy were 3.8%, 23.8%, 72.5% (Toronto) and 4.3%, 20.7%, 75.0% (LA) (p=0.88). No Vit D levels were in the toxic range. 25-OH Vit D levels correlated with Vit D supplement use (r=0.41, P<0.0001). 68% of women expressed willingness to participate in a Vit D RCT; however, only 12.7% of the study population met the pre-specified feasibility criteria. Conclusions: Vit D levels and supplementation rates are substantially higher in these BC patients than in previous cohorts, though more than 25% of women do not have adequate levels. Rates of adequacy did not differ between patients recruited in Toronto and LA. While the maj ority of women would be willing to participate in an RCT of Vit D supplementation, low levels of deficiency/insufficiency and high rates of supplement use may limit the feasibility of such a study. Funded by the Breast Cancer Research Foundation. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-13-09.

Abstract. In a complete geographic series of 294 cases of primary vulvar carcinomas prophylactic inguinal-femoral irradiation was used as a standard postoperative therapy. Inguinal lymph node dissection was performed in only 27 cases (9%) and was not part of the standard surgery. The histology was squamous cell carcinoma in 269 cases (92%). The primary surgery was total vulvectomy, partial vulvectomy, or local resection of the tumor. The main type of radiotherapy was adjuvant inguinal irradiation. Two separate, symmetrical and rectangular inguinal fields were irradiated with combined photon and electron beams. In the complete series 127 recurrences (43%) were recorded. Local (24%) and regional recurrences (19%) were most frequent. Type of surgery was not associated with the risk of tumor recurrence. The 5-year overall survival rate was 53% and the relapse-free survival (RFS) rate was 55%. Tumor grade was significantly (P=0.007) associated with the RFS. The inguinal RFS rate was 75% both for patients treated with adjuvant inguinal irradiation without lymphadenectomy and patients treated with primary lymphadenectomy ± inguinal irradiation. Postoperative complications were recorded in 22%. Postoperative complications occurred most frequently in the subgroup undergoing inguinal lymphadenectomy. Chronic lymph edemas were the most serious late tissue reactions.