In this work we estimated the budgetary impact of the samples produced by the biobank of the "Instituto Nacional de Cancerología" (BT-INCan) to set a recuperation fee from the perspective of the Health Ministry of Mexico. The study is an observational retrospective review of the direct medical costs (DMCs) of the processes involved in cryopreservation of the samples collected, on a per sample basis, including materials, laboratory tests, personnel, and administrative costs. Materials and labor costs were determined by information collected from the BT-INCan. DMCs were provided depending on the type of sample: plasma, tissue and biopsy; they were calculated according to the process required to preserve them. Sensitivity analysis was performed using bootstrap. Recuperation costs ranged from 130 to 155 USD. Costs were considered on a 5-year time frame for the maintenance per sample, which is the average time that a sample is kept in the BT-INCan. The cost analysis is perceived as an approximation to the most adequate recuperation fee per sample needed to guarantee the correct development of the BT-INCan. This work provides a basis and valuable information about costs, to enable several health institutions to strategically plan and manage a biobank or even motivate to establish their own biobank.

634 Background: Neoadjuvant treatment identifies subgroups of patients (pts) with different prognosis. In HER2+ BC, some tumors have been reported to be more sensitive to anti-HER2 therapy than others. We conducted an exploratory analysis in HER2+ BC women who received T-based neoadjuvant chemotherapy. Methods: Clinico-pathologic data from HER2+ BC pts who received neoadjuvant chemotherapy and T between January 2007 and May 2012 at the NCI were identified. Estrogen receptor (ER), progesterone receptor (PR) and HER2 expression were determined by immunohistochemistry and/or FISH. pCR was defined as complete absence of invasive tumor in breast and axillary nodes. Proportion differences were tested using the Chi-square test. A generalized linear model was used for multivariate analysis. Results: 243 pts received T-based neoadjuvant chemotherapy for localized HER2+ BC tumors. Median age was 49 (26-72) years. 96% had positive axillary nodes at diagnosis and median tumor size was 5.5 (1.5-20) cm. 49.4% had hormone receptor (HR) + (ER+ and/or PR+) and 50.6% HR negative (ER- and PR-) tumors. 63.4% pts achieved pCR. HR negative tumors reached significantly higher pCR rates than HR + tumors (69.9% vs. 56.7%, p=0.034). Pts with inflammatory BC (n=27) had a trend to achieve pCR less frequently than the non-inflammatory tumors (48.1% vs. 65.3%). Those who received taxane-anthracyline sequence chemotherapy (n=20) achieved pCR in 70% of the cases vs. 62.8% with anthracycline-taxane sequence. Differences among other variables (age, tumor size, nodes and HER2 positivity ++/+++) were not significant. Variables that positively influenced pCR were HR negative status (p=0.015), non-inflammatory BC (p=0.082) and chemotherapy sequence (p=0.086). Conclusions: HR negative HER2+ BC tumors were associated with higher pCR, consistent with neoadjuvant trial reports. Preclinical data suggest bi-directional crosstalk between HER2 and ER pathways, which might influence anti-HER2 agents and chemotherapy sensitivity for tumors co-expressing both receptors. New strategies are needed to overcome resistance for HER2+ HR+ BC tumors.

e11533 Background: The most accurate definition of pathologic complete response (pCR) in HER2+ BC patients (pts) receiving T-based neoadjuvant chemotherapy associated with improved DFS is controversial, particularly regarding the role of residual ductal carcinoma in situ (ypTis) and focal invasive residuals (ypT1mic). The effect of pCR on DFS in various subgroups of HER2+ BC is also uncertain. Methods: Pts with localized HER2+ BC that received T-based neoadjuvant chemotherapy at NCI between January 2007 and May 2012 were identified. We conducted an exploratory analysis of DFS in pts according to their tumor response. DFS curves were derived from Kaplan-Meier estimates and compared by log-rank test. Multivariate analysis was performed using Cox’s regression model. Results: 243 pts were included for analysis. Median follow-up was 39 months (mo). 49% of pts had no invasive and no in situ residuals at surgery (ypT0), 14.4% had ypTis/ypT1mic residuals and 36.6% had gross residual BC. DFS was significantly superior in pts with both ypT0 and ypTis/ypT1mic (no gross invasive residual BC) compared with those with gross residual disease (60.6 and 62.7 mo respectively vs. 51.6 mo, p=0.011 and 0.017). There was no difference in DFS between ypT0 and ypTis/ypT1mic pts (p=0.402). The rate of no gross invasive residual BC was significantly superior in pts with ER-PR- tumors compared with patients with ER+/PR+ tumors (69.9% vs. 56.7%, p=0.034). No gross invasive residual BC was associated with improved DFS in pts with HER2+ ER-/PR- (60.3 vs. 49.0 mo; p=0.005), as opposed to HER2+ ER+/PR+ tumors (61.0 vs. 51.6 mo; p=0.100). Multivariate analysis showed that tumor size (p=0.013) and no gross invasive residual BC (p=0.13) were associated with improved DFS in all subgroups. Conclusions: The absence of gross invasive residual BC was associated with improved DFS in pts with HER2+ BC treated with T-based neoadjuvant chemotherapy, particularly in those with HER2+ ER-/PR- BC. Our data suggest a comparable DFS in HER2+ BC patients with no gross invasive residual BC regardless of the presence or absence of both ypTis and ypT1mic disease after neoadjuvant treatment.