ESMO Congress 2023 | OncologyPRO

Abstract 465P

Background

Although older women comprise a large and rapidly growing proportion of patients diagnosed with breast cancer, the trial-level evidence base for treating this population is limited. This study assessed the completeness of reporting of older subgroups enrolled to registration trials in breast cancer between 2012-2021.

Methods

Trials which supported novel FDA approvals of systemic therapies in breast cancer between 01/2012 and 12/2021 were included. Individual trial-level PUBMED searches according trial/drug name, and trial registration number, were conducted on 31/08/22. Following title/abstract review, relevant publications and supplementary material were retrieved. Clinicaltrials.gov registry data was also retrieved. Non-efficacy (n = 1), site-agnostic (n = 1) biosimilar (n = 4), and trials conducted exclusively among premenopausal women (n = 1), were excluded. Immature endpoints (n = 5), for which no interim data were available in the full cohort, and studies which did not collect HRQOL data (n = 3), were excluded from relevant analyses. The availability and completeness of data for baseline characteristics, protocol-defined (co-)primary and secondary efficacy endpoints, toxicity, and HRQOL among older subgroups, was assessed systematically by two reviewers according to methods adapted from Chan & Altman (JAMA, 2004).

Results

27 trials were included. 785 unique publications were identified, of which 569 were excluded. 216 publications (median: 6 per trial, IQR: 4), and registry data, were assessed in full. 20.3% of enrolled patients were aged ≥65. 70.0% of patients were ECOG 0; 29.8% ECOG 1, and 0.2% ECOG 2. The completeness of data across efficacy endpoints, baseline characteristics, toxicity and HRQOL domains are reported in the table. Table: 465P

Completeness of reporting of geriatric subgroups enrolled to registration trials in breast cancer 2012-2022

		n	Complete	Partial	Qualitative	Unreported
Efficacy endpoints
	All efficacy endpoints	133	37 (27.8%)	3 (2.3%)	8 (6.0%)	95 (71.4%)
	Primary endpoints	33	24 (72.7%)	3 (9.1%)	1 (3.0%)	5 (15.2%)
	Secondary endpoints	110	13 (11.8%)	0 (0.0%)	7 (6.4%)	90 (81.8%)
	Overall survival	22	11 (50.0%)	1 (4.5%)	2 (9.1%)	8 (36.4%)
Baseline Characteristics		27	6 (22.2%)	2 (7.4%)	0 (0.0%)	19 (70.4%)
Toxicity		27	12 (44.4%)	0 (0.0%)	0 (0.0%)	15 (55.6%)
HRQOL		24	1 (4.2%)	0 (0.0%)	2 (8.3%)	21 (87.5%)

Rows 1-4: n Endpoints (%) Rows 5-7: n Trials (%).

Conclusions

This study identified significant gaps in the reporting of older subgroups enrolled to registration breast cancer trials. Improved reporting practices are required to support evidence-based decision making in this population.