Under-representation of older Indian persons with cancer in clinical trials

Abstract

Objective: Older patients with cancer have traditionally been under-represented in global clinical trials. There are no data from India regarding this issue.

Methods and analysis: This was a retrospective analysis done at our institute on interventional studies conducted between 2003 and 2023 in adult patients with malignancies. We excluded studies done exclusively in the paediatric population and observational studies.

Results: We included 21 894 patients enrolled in 150 interventional trials from the departments of surgical, medical, and radiation oncology, anaesthesia, and clinical pharmacology; 110 (73.3%) were investigator initiated. There were 38 trials (25.3%) in breast cancer (6141 patients, 28%), and 33 (22%) in head and neck cancer (6975 patients, 31.9%). Studies were predominantly phase III (97 trials (64.7%)). Multicentric studies comprised approximately one-third (48, 32%). The median age of enrolled patients was 51 years (IQR 43-59). There were 5132 (23.4%) participants aged ≥60 years, 2678 (12.2%) ≥65 years and 1045 (4.8%) ≥70 years. Data from the hospital registry revealed that 30% of adult registrations were ≥60 years. There was a significant increase in the proportion of older patients enrolled in clinical trials from 2003 (8%) to 2019 (22%) compared with their proportion in the hospital registry (stable at 28%-29%); p<0.001.

Conclusion: There is a gap between the proportion of older Indian adults with cancer in the hospital registry and those enrolled in interventional clinical trials, however, this gap has shrunk over time. Various factors that limit the recruitment of this vulnerable cohort like age-specific eligibility criteria are immediately actionable to make clinical trials more inclusive.

Keywords: Medical oncology.

Figure 1. Proportion of older adults with cancer enrolled in clinical trials as compared with the proportion of similar age patients in the hospital registry.

Figure 2. Enrolment of older persons with cancer in clinical trials in various age categories, according to various factors: (A) centres at which the trials were conducted, that is, single centre versus multicentric; (B) trial sponsor: pharmaceutical company sponsored, versus investigator initiated; (C) intent of therapy: curative, versus palliative, versus not specified (supportive care, etc); (D) phase of the study (phase I vs II vs III vs IV vs others; (E) whether the trial was randomised (yes vs no); (F) whether survival was the primary endpoint of the study (yes vs no); (G) whether survival was a secondary endpoint (yes vs no); (H) whether quality of life (QoL) was an endpoint; (I) type of systemic therapy (oral vs intravenous cytotoxic vs intravenous anticancer medicines other than cytotoxic like immunotherapy and targeted therapy) and (J) age as part of eligibility criteria (yes vs no).

Figure 3. Univariate logistic regression to evaluate the factors that impacted the recruitment of older adults with cancer in interventional clinical trials.

Figure 4. The time trend of the proportion of older adults with cancer enrolled in interventional clinical trials as compared with the proportion in the hospital registry over time.