Bridging the age gap in breast cancer: cluster randomized trial of two decision support interventions for older women with operable breast cancer on quality of life, survival, decision quality, and treatment choices

Abstract

Background: Rates of surgery and adjuvant therapy for breast cancer vary widely between breast units. This may contribute to differences in survival. This cluster RCT evaluated the impact of decision support interventions (DESIs) for older women with breast cancer, to ascertain whether DESIs influenced quality of life, survival, decision quality, and treatment choice.

Methods: A multicentre cluster RCT compared the use of two DESIs against usual care in treatment decision-making in older women (aged at least ≥70 years) with breast cancer. Each DESI comprised an online algorithm, booklet, and brief decision aid to inform choices between surgery plus adjuvant endocrine therapy versus primary endocrine therapy, and adjuvant chemotherapy versus no chemotherapy. The primary outcome was quality of life. Secondary outcomes included decision quality measures, survival, and treatment choice.

Results: A total of 46 breast units were randomized (21 intervention, 25 usual care), recruiting 1339 women (670 intervention, 669 usual care). There was no significant difference in global quality of life at 6 months after the baseline assessment on intention-to-treat analysis (difference -0.20, 95 per cent confidence interval (C.I.) -2.69 to 2.29; P = 0.900). In women offered a choice of primary endocrine therapy versus surgery plus endocrine therapy, knowledge about treatments was greater in the intervention arm (94 versus 74 per cent; P = 0.003). Treatment choice was altered, with a primary endocrine therapy rate among women with oestrogen receptor-positive disease of 21.0 per cent in the intervention versus 15.4 per cent in usual-care sites (difference 5.5 (95 per cent C.I. 1.1 to 10.0) per cent; P = 0.029). The chemotherapy rate was 10.3 per cent at intervention versus 14.8 per cent at usual-care sites (difference -4.5 (C.I. -8.0 to 0) per cent; P = 0.013). Survival was similar in both arms.

Conclusion: The use of DESIs in older women increases knowledge of breast cancer treatment options, facilitates shared decision-making, and alters treatment selection. Trial registration numbers: EudraCT 2015-004220-61 (https://eudract.ema.europa.eu/), ISRCTN46099296 (http://www.controlled-trials.com).

Fig. 1

Design of cluster RCT DESI, decision support intervention; ET, endocrine therapy.

Fig. 2

CONSORT diagram for the trial. (ET, endocrine therapy; QoL, quality of life).

Fig. 3

Lowess smoother plots a,b Proportion of patients with oestrogen receptor-positive disease who had primary endocrine therapy (ET) and c,d proportion of high-risk patients after surgery who underwent adjuvant chemotherapy, at RCT a,c intervention and b,d usual-care sites. Dashed line denotes time at which first patient recruited during RCT phase. Blue line is the percentage of patients having the intervemtion of interest. Bandwidth 0.4 for all parts.

Fig. 4

Overall survival, cause-specific survival and time to recurrence Intention-to-treat (ITT) analysis of a overall survival (hazard ratio (HR) 1.07, 95 per cent c.i. 0.80 to 1.43; P = 0.633), b cause-specific survival (HR 0.86, 0.54 to 1.44; P = 0.609), and c time to recurrence (HR 0.86, 0.51 to 1.43; P = 0.558); per-protocol (PP) analysis of d overall survival (HR 0.81, 0.49 to 1.33; P = 0.404), e cause-specific survival (HR 0.56, 0.24 to 1.29; P = 0.171), and f time to recurrence (HR 0.48, 0.17 to 1.31; P = 0.150).