Abstract P3-10-07: Impact of enrollment in clinical trials on survival of metastatic breast cancer patients

Background: The number of patients worldwide with metastatic breast cancer (MBC) who participate in therapeutic clinical trials has remained so far low. One of the reasons is a lack of opportunity, whereas another is fear of health care providers and patients of poor outcome of the use of new drugs. We therefore investigated whether survival in patients with MBC who participated in first-line therapeutic clinical trials is worse than that in patients who received only standard care and never enrolled in a clinical trial. We hypothesized that first-line therapeutic clinical trials do not negatively affect survival outcome. Methods: We reviewed the records of 5501 patients with MBC treated at The University of Texas MD Anderson Cancer Center from January 2000 to December 2010. We extracted a first cohort of 285 patients enrolled in a therapeutic clinical trial for the first time for first-line systemic MBC treatment. The second cohort, referred to as the eligible control population, consisted of 367 patients without comorbidities who did not participate in a clinical trial at any stage of their disease; these patients lived in Harris County, in which MD Anderson is located, and thus could be potentially eligible for MD Anderson's financial assistance program. To limit confounding factors, we excluded male patients and patients with known brain metastasis from both cohorts. Results: The median follow-up duration in our cohort was 7.16 years (95% confidence interval [CI], 6.53-7.64 years). We observed discrepancies in race (minorities were less represented in the clinical trial arm), estrogen receptor (ER) status (more ER-positive than ER-negative patients participated in clinical trials), and metastatic disease site (fewer patients with bone metastasis participated in clinical trials) between the two groups. Overall, we observed no significant differences in progression-free survival (PFS) or overall survival (OS) duration between the treatment arms. Specifically, in the clinical trial cohort, the median PFS duration was 7.00 months (95% CI, 5.72-8.71 months), and the median OS duration was 28.48 months (95% CI, 22.70-34.60 months). In the control cohort, the median PFS duration was 10.02 months (95% CI, 7.13-11.99 months), and the median OS duration was 28.71 months (95% CI, 24.41-31.31 months) (P = .089 and .335, respectively). Conclusion: In MBC patients, enrolling in first-line therapeutic clinical trials does not result in worse survival than does never enrolling in a clinical trial. This study should reassure health care providers in demonstrating that enrollment in a clinical trial does not negatively affect survival in MBC patients.

Citation Format: Le Du F, FUJII T, Park M, Liu D, Hsu L, Gonzalez-Angulo A-M, Ueno NT. Impact of enrollment in clinical trials on survival of metastatic breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-07.