Abstract S6-04: Patient-reported outcome (PRO) results, NRG Oncology/NSABP B-35: A clinical trial of anastrozole (A) vs tamoxifen (tam) in postmenopausal patients with DCIS undergoing lumpectomy plus radiotherapy
Authors: Ganz PA , Cecchini RS , Julian TB , Margolese RG , Costantino JP , Vallow LA , Albain KS , Whitworth PW , Cianfrocca ME , Brufsky A , Gross HM , Soori GS , Hopkins JO , Fehrenbacher L , Sturtz K , Wozniak TF , Seay TE , Mamounas EP , Wolmark N 
Published: May 2016

Background

The clinical results of NSABP B-35, phase III trial comparing 1 mg/day A to 20 mg/day tam, each given for 5 years, were reported at ASCO 2015. B-35 demonstrated a statistically significant benefit in breast cancer free interval for women assigned to A, primarily in women &lt;60 years. A secondary endpoint of B-35 was quality of life (QOL) and symptom (SX) outcomes in the two treatment groups. The primary hypotheses of the PRO study were that there would be no differences in QOL between the two treatments, and that patients receiving A would report higher rates of hot flashes compared to patients receiving tam. Other SX comparisons were secondary endpoints.

Methods

QOL and SX were assessed at baseline (prior to randomization), and every 6 months thereafter for 5 years of treatment and in the following 12 months. QOL was measured with the SF-12 Physical Component Summary (PCS) and Mental Component Summary (MCS). SX were measured with selected scales from the BCPT symptom-checklist, and other standardized instruments. Stratification was by age (&lt;60 v ≥60) as in the main trial. Study hypotheses and endpoints were examined by comparing PROs in the two treatment arms using a mixed model for repeated measures analysis with adjustment for the baseline scores, time point and age category, using an intention-to-treat principle and including only patients who completed the baseline and at least one follow-up questionnaire. Patients with protocol events were censored. Only data through 60 months are reported here. The accrual goal for the sub-study was 1,150 consecutive patients.

Results

Between January 6, 2003 and June 15, 2006, a total of 3,104 patients were entered and randomly assigned to NSABP Protocol B-35. Accrual to the PRO study of B-35 closed on December 28, 2004, at which time 1,275 patients were entered, with 1,193 patients included in this analysis. There were no medical or demographic differences between patients assigned to A or tam in the PRO sub-study, and they reflected the characteristics of the parent trial. Adherence to data collection across the 60 months was 87%. There were no significant differences in QOL outcomes by treatment for the PCS (p=0.16) or the MCS (p=0.38). SX subscales: hot flash scale was greater in tam group and this difference varied over time (p=0.001); musculoskeletal pain was significantly greater in A group for time points 6-24 months (all p&lt;.001); vaginal problems were greater in A group (p=0.03). Hot flash and vaginal problems were significantly worse in women &lt;60 years. Additional SX outcomes (depression, fatigue, sexual function) will be reported at presentation.

Conclusion

In this large, double-blind, placebo-controlled trial comparing A to tam in patients with DCIS, there was no significant difference in QOL between the two treatments. However, there were important treatment differences in SX outcomes, which should be considered as part of treatment decision-making discussions, along with the clinical breast cancer outcome results.

Support: CA-180868, 180822, 189867, 196067, 114732; AstraZeneca Pharmaceuticals LP.

Citation Format: Ganz PA, Cecchini RS, Julian TB, Margolese RG, Costantino JP, Vallow LA, Albain KS, Whitworth PW, Cianfrocca ME, Brufsky A, Gross HM, Soori GS, Hopkins JO, Fehrenbacher L, Sturtz K, Wozniak TF, Seay TE, Mamounas EP, Wolmark N. Patient-reported outcome (PRO) results, NRG Oncology/NSABP B-35: A clinical trial of anastrozole (A) vs tamoxifen (tam) in postmenopausal patients with DCIS undergoing lumpectomy plus radiotherapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S6-04.