Real world patterns of care in HER2-overexpressing breast cancer: Results of a survey of TEACH clinical trial investigators in 2011.

BACKGROUND: HER2-overexpressing breast cancer (BC) is common among young patients and poses a public health burden. Adjuvant anti-HER2/neu therapy with trastuzumab reduces the risk of recurrence and improves survival. METHODS: A web-based survey was sent to 386 physicians of the "TEACH" trial in 2011 to determine access to HER2/neu testing and treatment patterns for HER2-overexpressing BC. RESULTS: There were 151 responders (39%) from 28 countries. Ninety-seven percent reported HER2/neu expression is routinely measured in their institutions by immunohistochemistry (85%), FISH (80%) and other methods (16%). Twenty percent of responders from Asia reported that the test was not routinely available. Forty-eight percent of participants reported instances when adjuvant HER2-directed therapy was recommended to a patient who eventually did not receive it. Reasons for not receiving trastuzumab was cost (73%, p < 0.0001) in low- and middle-income countries and co-morbidities in high-income countries (43%, p = 0.003). CONCLUSIONS: This survey reflects the availability of HER2/neu testing and anti-HER2/neu therapy among physicians who participated in TEACH. A high proportion of women with HER2-overexpressing BC may not receive standard adjuvant therapy due to unavailability of the test and cost of therapy. Despite having some limitations, such as a possible selection bias of participating physicians, variable definitions of access to healthcare among respondents, and changes in trastuzumab availability since 2011, our results demonstrate that access to care and region of practice impact the implementation of cancer treatments.

Drug withdrawal in women with progressive metastatic breast cancer while on aromatase inhibitor therapy.

BACKGROUND: Acquiring resistance to endocrine therapy is common in metastatic hormone-receptor-positive breast cancer (MBC). These patients most often transition either to next-line endocrine therapy or to systemic chemotherapy. However, withdrawal of endocrine therapy and observation as is selectively practiced in prostate cancer is another potential strategy for breast cancer patients. METHODS: A prospective, single-arm phase II trial of aromatase inhibitor (AI) withdrawal was performed in women with MBC, who had disease progression on AI therapy. The primary objective was to estimate the clinical benefit rate (defined as complete or partial response, or stable disease for at least 24 weeks, by RECIST criteria). Participants were monitored clinically and radiographically off all therapy at 8, 16 and 24 weeks after treatment and every 12 weeks thereafter until disease progression. RESULTS: Twenty-four patients (of 40 intended) were enrolled when the study was closed due to slow accrual. Clinical benefit rate overall was 46% (95% CI 26% to 67%). Median progression-free survival from time of AI withdrawal was 4 months. Two patients have remained progression free, off all treatment, for over 60 months. CONCLUSIONS: Despite suboptimal patient accrual, our results suggest that selected patients with metastatic breast cancer progressing on AI therapy can experience disease stabilisation and a period of observation after AI withdrawal. A randomised phase II trial is planned.