As more targeted therapies and immunotherapies are continuing to reach the oncology market, there has been an increasing number of clinical trials. These new therapeutic options have helped improve adverse effect profiles, making treatment more tolerable for many patients. However, at the same time, there is a greater need to collect data on patient subgroups. Balanced enrollment in clinical trials offers an opportunity to understand if variances in ethnicity, age, and sex leads to differences in drug efficacy and tolerability, explains Narjust Duma, MD.


A New In-Depth Analysis

For a study published in the Journal of Oncology Practice, Dr. Duma and colleagues reviewed enrollment patterns of all completed cancer clinical trials in the several of the most prevalent tumor types over the past 14 years. They compared participation in clinical trials by race, ethnic group, and sex and assessed changes in recruitment over time by analyzing enrollment data from all completed therapeutic trials in from 2003 to 2016.

“Of the more than 1,000 clinical trials assessed, we found that participation varied significantly across ethnic groups,” says Dr. Duma. “For example, non-Hispanic whites were more likely to be enrolled in clinical trials than African Americans and Hispanics.” A decrease in African American and Hispanic enrollment was observed when compared with historical data from 1996 to 2002 (Table). Low recruitment of female patients was also seen in clinical trials for melanoma (35%), lung cancer (39%), and pancreatic cancer (40%). In addition, the authors found that patients younger than 65 were more likely to be enrolled in clinical trials than their older counterparts (64% vs 36%).


A Better Understanding Matters

Gaining a better understanding on the factors that contribute to disparities in clinical trials enrollment is critical. Recent studies have identified several individual patient factors that are barriers to improving disparities in clinical trials. These include cost, a fear of adverse effects, mistrust in science, cultural or religious beliefs, and poor research or health literacy. “Many of these factors are easily modifiable,” says Dr. Duma.

The strategies adopted by investigators over the past 14 years have not been effective at reaching minorities, women, and the elderly. If a subset of patients is underrepresented or excluded, important information on the proper use of cancer drugs and their efficacy in that subgroup will be lacking. “There needs to be a conscious effort to develop tools to improve communication and education among minority cancer populations and physicians to increase enrollment in clinical trials,” says Dr. Duma.


Taking a Proactive Approach

There are several ways for investigators and sponsors to achieve a more representative sample of all groups of patients participating in cancer clinical trials. Clinicians are encouraged to:

  1. Describe the racial composition of study participants in all clinical trials.
  2. Make efforts to adopt new strategies to increase enrollment of minorities, the elderly, and women, especially when an indication of a new drug is for a highly prevalent cancer in these subgroups.
  3. Consider possible physician barriers to minority recruitment, including provider bias.
  4. Address socioeconomic factors that may hinder minority recruitment.
  5. Consider hiring multilingual personnel to improve communication and trust between trial participants and research teams.

Clinical trials provide the necessary data for the rational use of new cancer drugs. “Clinicians need to proactively educate patients on the availability and benefits of participating in these trials,” Dr. Duma says. “The disparities observed in our analysis are highly relevant to the rapidly changing demographics in the United States. We need to improve our understanding of current and future challenges affecting recruitment of minorities and women so that we can overcome these issues and ensure broader access to oncology clinical trials.”