Abstract P1-11-09: Early discontinuation of adjuvant chemotherapy in women with early stage breast cancer: The BQUAL study

BACKGROUND Adjuvant chemotherapy for early stage breast cancer decreases recurrence and increases survival. However, early discontinuation of chemotherapy occurs frequently and has a negative influence on patient outcomes. METHODS The Breast Cancer Quality of Care Study (BQUAL) is a prospective cohort study designed to investigate factors associated with early discontinuation of adjuvant chemotherapy among women diagnosed with non-metastatic breast cancer at three sites in the U.S between 2006 and 2010 (Columbia University Medical Center, Kaiser-Permanente of Northern California, Henry Ford Health System). Chemotherapy regimens were classified based on NCCN guidelines. Regimens were further categorized as standard and non-standard/experimental. Early discontinuation for standard treatments was defined as missing 20% of the recommended number of treatments for the prescribed regimen. We used multivariate analysis to examine the association between early discontinuation and sociodemographic factors, tumor characteristics, and baseline psychosocial factors. RESULTS Of 1157 women recruited, 478 patients initiated chemotherapy; 35 women received non-standard/experimental chemotherapy and an additional 17 did not complete all interviews and were excluded from the analysis. Of the remaining 426 patients, 59 (13.9%) did not complete the full course of prescribed chemotherapy. In multivariate analysis, compared to those who completed their full prescribed course of adjuvant chemotherapy, those who discontinued were more often >50 years of age (p=0.04). Early discontinuation of chemotherapy was less likely among Asian women (OR 0.12, 95% CI 0.01-0.96), those who held positive beliefs related to the efficacy of chemotherapy (OR 0.43, 95% CI 0.22-0.81), and those who were more optimistic (OR 0.93, 95% CI 0.86-0.99). Women prescribed chemotherapy regimens that had more cycles (>5 cycles) or contained paclitaxel/docetaxel were significantly more likely (OR 7.54, 95% CI 2.68-21.20 and OR 5.02, 95% CI 1.59-15.83, respectively) to discontinue chemotherapy treatment early than regimens with 6 or less cycles. CONCLUSIONS Women prescribed longer regimens were significantly more likely not to complete the full course. Positive beliefs about the efficacy of treatment were associated with continuation of treatment. Educational interventions focused on the importance of completing therapy may increase chemotherapy adherence. Citation Format: Alfred I Neugut, Grace C Hillyer, Lawrence W Kushi, Lois Lamerato, Jinjoo Shim, Dana H Bovberg, David Nathanson, Christine B Ambrisone, Jeanne S Mandelblatt, Carol Magai, Wei Yann Tsai, Judith S Jacobson, Dawn L Hershman. Early discontinuation of adjuvant chemotherapy in women with early stage breast cancer: The BQUAL study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-11-09.