Pérez, E.

557 Background: Aromatase inhibitors (AIs) are a novel hormonal therapy for breast cancer. However, AIs can cause bone loss by blocking estrogen production. This study aims to assess the association between AIs and treatment-related bone loss in a large managed care population of women with breast cancer. Methods: Using medical and pharmacy claims data from over 5 million beneficiaries between 01/01/1998 and 01/31/2005, we identified 12,368 patients with ≥ 2 breast cancer claims in a 6-month period, who also had no bone metastasis and no prior osteoporosis or fracture claims. Patients who received anti-estrogen therapy were also excluded to remove the protective confounding effects. 1,354 patients receiving an AI (anastrozole, exemestane, letrozole) were compared to 11,014 controls who did not receive an AI with respect to their risk of bone loss. The observation start date for the AI and control groups was defined as the service date of the first AI claim and breast cancer claim, respectively. The bone loss endpoints analyzed were osteoporosis (including osteopenia) and clinical fractures. Results: The univariate analysis found that the prevalence of osteoporosis was 8.7% in the AI group vs. 7.1% in the control group, resulting in a statistically significant relative risk of 1.3 (95% CI=1.1–1.6, p=0.01). The prevalence of bone fracture was also statistically significantly elevated in the AI group compared to the controls (13.5% vs. 10.3%) with a relative risk of 1.4 (95% CI=1.2–1.6, p=0.001). Multivariate Cox proportional hazards regressions showed that after adjusting for age and comorbidities, the risk of bone loss remained statistically significantly higher in the AI group than the non-AI group, with 27% (95% CI=4%-55%, p=0.02) and 21% (95% CI=3%-43%, p=0.02) increase in the risk of osteoporosis and fractures, respectively. Conclusions: This retrospective longitudinal analysis of a large cohort of breast cancer patients corroborates previous findings from smaller clinical trials and demonstrates that AI therapies carry an increased risk of bone loss. Monitoring and treatment management strategies to alleviate bone loss risk are warranted in women receiving AI for breast cancer. [Table: see text]

1071 Background: N0234 is a phase II trial of gemcitabine at 1000 mg/m2 days 1 and 8 of a 21 day cycle and erlotinib at 150 mg daily in patients with previous therapy with either an anthracycline or a taxane for MBC. A partial response (PR) rate of 17% has been reported (ASCO 2005). Recent information suggests that over-expression of the EGFR pathway is frequent in patients with TNeg MBC. Methods: Tissue and serum were obtained for translational studies of ER, PR, HER2, and proteins related to EGFR pathway on tissue using immunohistochemistry; CK19, mammoglobin, and TTK on circulating tumor cells (CTCs). Markers were evaluated centrally, blinded to patient outcome. Complete data were available in 57 of 59 eligible patients; 20/57 patients (pts) were TNeg. Results: A PR rate of 25% and clinical benefit rate (PR + stable disease > 6 months)of 25% was observed in TNeg pts as compared to a PR rate of 14% (p = 0.30) and clinical benefit rate 22% (p= 0.75) for non-TNeg pts. Median progression free survival 72 days vs 98 days (p=0.13) and overall survival 227 days vs 738 days (p<0.001) were shorter for TNeg pts. Translational results for the EGFR pathway proteins and CTC analysis is forthcoming. Conclusions: The combination of gemcitabine and erlotinib appears to be as active in the non-TNeg and TNeg subset of patients on this trial. TNeg patients had an inferior clinical result, confirming the poor outcome seen in these patients. Data for the remaining biomarkers potentially predictive of activity will be presented. Supported by CA-25224, CA-37404. [Table: see text]

Abstract Background: Postmenopausal women with significant osteopenia/osteoporosis are at increased risk of fracture, a risk that is exacerbated by the use of Aromatase Inhibitors (AIs). Bisphosphonates may be used for these patients because there is no known interaction with estrogen and/or progesterone receptors (ER, PR). This study evaluated the concurrent use of zoledronic acid in patients with significant osteopenia or osteoporosis who received initial adjuvant letrozole therapy for primary BC, to determine if further bone mineral density (BMD) loss could be prevented.Methods: Postmenopausal women with Stage I-IIIa, ER and/or PR + BC, no evidence of metastatic disease, and a BMD T-score &lt; -2.0 were treated with daily letrozole 2.5 mg/d, vitamin D 400 international units/d, calcium 500 mg twice daily, and 4 mg I.V. zoledronic acid every 6 months (for 5 years). The BMD was measured at baseline and at one year. Kruskall-Wallis p-value methodology was used as the method of statistical analysis. Since this was a single-arm study, the analysis plan was primarily descriptive. The primary endpoint was the mean change in lumbar spine (LS) BMD at 1 year.Results: 60 patients were enrolled; 46 completed 1 year of treatment. Mean patient age was 67 years, with 44% having taken prior tamoxifen. At 1 year (see figure 1), LS BMD increased 2.66% (p=0.01), femoral neck (FN) BMD increased 4.81% (p=0.01), and any measured endpoint (within the LS or FN) increased 4.55% (p=0.0052). 7% of patients experienced a fracture vs.13% with a pre-existing history of fracture before enrollment. No patients had disease recurrence during year 1. Toxicity was minimal with arthralgia as the most common complaint. There were no reports of osteonecrosis of the jaw.Conclusion: Zoledronic acid prevents additional bone loss in postmenopausal women with significant osteopenia or osteoporosis initiating letrozole. Treatment with zoledronic acid was associated with an improvement in BMD. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2103.

Abstract Background: Adenoid cystic carcinoma of the breast is a rare type of breast cancer accounting for approximately 0.1% of all breast cancer and less than 200 cases are reported in the literature. Hence, data for treatment and outcome are limited. This retrospective review reports the Mayo Clinic's experience.Methods: We identified 30 patients between 1971 and 2009 who were diagnosed with adenoid cystic breast cancer at Mayo Clinic Rochester, Arizona or Florida. Median follow-up was 62 months with a range of 1 to 424 months. Data regarding demographics (age, gender, and race), tumor characteristics (size, grade, and margin status), biological features (Estrogen receptor (ER), Progesterone receptor (PR) status, HER2 status) and clinical course (recurrence, secondary treatment) were collected. Disease free survival was calculated using Kaplan Meier estimates.Results: The median age of all patients was 58 (range, 22 – 78 years). All were female. Median tumor size was 1.3 cm (range, 0.6 – 8.5cm). Axillary lymph node sampling (sentinel or complete dissection) was performed in 15 patients. No patient had lymph node positive disease on presentation. The majority of patients had hormone receptor negative disease. Only 3 patients (10%) had weak hormone receptor (1-10%) positivity. No tumors were HER2 positive. Only two patients had high grade disease. Initial surgical data only available in twenty one patients: fifteen (50%) were treated with lumpectomy and adjuvant radiation, and 6 (20%) were treated with mastectomy. There were no local recurrences. Only one patient was treated with adjuvant chemotherapy (with cyclophosphamide, methotrexate and fluorouracil (CMF) followed by tamoxifen) but still suffered a distant recurrence within 5 years. There were a total of five patients that recurred. The 5-year disease free survival (DFS) rate for the entire cohort was 90%, and 10 year DFS was 83%. Median time to recurrence was 47.5 months (Range, 23-77 months). Recurrence occurred almost exclusively in patients with ≥ T2 disease. The primary site of metastases was lung (80%) and bone (20%) but subsequent liver and brain metastases were also seen. Treatments at relapse included surgical resection, radiosurgery and chemotherapy.Conclusion: Adenoid cystic carcinomas of the breast are rare but have overall good prognosis. This review confirms that the majority of these patients present with node negative disease, low to intermediate histologic grade and endocrine unresponsive tumors. Primary treatment is surgery (mastectomy or lumpectomy plus radiation) and there seems to be no role of any adjuvant therapy at the present time. In general, recurrences (80%) occurred with tumors larger than 2 cm and adjuvant chemotherapy and/or targeted therapy could be explored for selected patients in the context of a clinical trial. Overall mortality after recurrence was 50% but median overall survival was variable in years (1-14 years). Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2055.