"If elderly patients do not participate in clinical trials, the treatments resulting from those trials may not be appropriate for them," said Lilia Talarico, MD, of the Division of Oncology Drug Products and Center for Drug Evaluation and Research at the Food and Drug Administration and lead author of the study. "This is a significant concern, given that elderly patients represent the majority of cancer patients in the U.S." Dr. Talarico noted that the FDA recommends that treatments be studied in all age groups for which they will have significant utility, including the elderly, so that the true risks and benefits can be assessed.
Researchers performed a retrospective analysis of 28,766 people participating in 55 clinical trials of new cancer drugs or new indications of already approved cancer drugs from 1995 to 2002. Data on trials for the treatment of leukemia, lymphoma, and cancers of the breast, lung, colon, ovary, pancreas and central nervous system were analyzed according to the following age groups: 65 and older, 70 and older, and 75 and older. The rates of enrollment for elderly patients for each cancer were compared to the corresponding rates in the U.S. cancer population.
Overall, researchers found that patients 65 and older comprised 60% of the U.S. cancer population, but only 36% of the clinical cancer study population. Patients aged 70 and older comprised 46% of the U.S. cancer population, but only 20% of the study population, while patients 75 and older represented 31% of the U.S. cancer population, but only 9% of the study population.
Researchers suggest that elderly patients are less likely to be asked or may be less willing to enroll in clinical trials because of concerns that the treatment will be ineffective or cause debilitating side effects and a reduced quality of life.
Elderly patients were underrepresented in trials for all cancer treatments except those examining breast cancer hormonal therapies. Researchers suggest that this likely reflects the general acceptance among both patients and physicians that hormonal therapy is well tolerated and effective in reducing recurrence and death in women of all ages, including older women.
To increase elderly participation in clinical cancer trials, researchers recommended treatment modifications, study protocols designed for elderly cancer patients, and less stringent eligibility criteria based on cancer and patient characteristics. Elderly patients tend to be excluded from studies with stringent eligibility criteria because of health limitations and concerns about their ability to tolerate chemotherapy, researchers noted.
"Additional concerns for older patients including health care costs, lack of social and home care support, and difficulties with access to care constitute significant barriers. These are not usually considered in the evaluation and treatment of younger patients," said Dr. Talarico.
"Increasing life expectancy has led to a growth in the U.S. elderly population, making it even more critical that elderly cancer patients have better access to clinical cancer trials and treatments," Dr. Talarico added. "With the development of new, selective, and better tolerated treatments, improved access should be possible."
The Native American Project: Increasing Access to Clinical Trials
An overview of a cancer research project aimed at increasing access to clinical trials and new technologies among Native Americans in South Dakota will also appear in the November 15 issue of the JCO.
The project, a partnership of Rapid City Regional Hospital, the University of Wisconsin Comprehensive Cancer Center, and the Mayo Rochester Comprehensive Cancer Center, was awarded a five-year $5.4 million grant from NCI's Cancer Disparities Research Partnership (CDRP) to lower cancer mortality rates, and increase clinical trial participation among Native Americans, who experience higher cancer death rates than the general population largely because they are often diagnosed with more advanced stages of disease.
The project focuses on the Lakota (Western Sioux) population in South Dakota and has three main objectives: to identify the major factors responsible for health care disparities among Native Americans served by Rapid City Regional Hospital; to determine whether shorter, but equally effective courses of treatment will enhance the acceptability and completion rate of radiotherapy; and to establish whether there is a genetic basis for anecdotal reports that Native Americans experience greater side effects from radiation therapy.
Researchers noted that a number of geographic, cultural, and socioeconomic barriers keep Native Americans from accessing clinical trials and other components of quality cancer care. They found that the distance between the hospital and reservation (average of 110 miles) is often so great that many Native Americans cannot complete a full course of radiation, which typically lasts 6-8 weeks. In addition, cultural beliefs may influence Native Americans to rely solely on traditional healers instead of seeking care at a cancer clinic.
To address these issues, the researchers designed clinical trials involving innovative therapies that will shorten treatment time significantly, to 1-4 weeks. Therapies include helical tomotherapy and brachytherapy, which target the cancerous tissue while avoiding nearby healthy tissue.
In addition, the project includes a "patient navigator program" – a grass roots effort involving both researchers and members of the community that will provide culturally appropriate education to the community on cancer prevention, screening, and treatment; facilitate participation in the project's clinical trials and community survey; and assist Native American cancer patients in utilizing the health care system.
Finally, the project will offer a genetic test to determine whether Native Americans carry a gene that may cause them to experience more severe side effects from radiation. A particular DNA repair gene will be investigated.
"Traditionally, Native Americans have been less likely to benefit from the progress being made in cancer research because of a multitude of barriers," said Daniel Petereit, MD, principal investigator for the project and radiation oncologist at the John T. Vucurevich Cancer Care Institute in Rapid City, South Dakota. "To address these barriers, we are working closely with Sioux Nation to develop innovative approaches that will ensure Native Americans have equal access to the best possible care."
In addition, researchers noted that they hope findings from the Native American project can serve as a model for improving access to clinical trials and quality cancer care among the many underserved populations in the United States.
"Enrollment of Elderly Patients in Clinical Trials from Cancer Drug Registration: A 7-year experience by the Food and Drug Administration (FDA)." Lilia Talarico, et al, Division of Oncology Drug Products and Center for Drug Evaluation and Research at the Food and Drug Administration, Rockville, MD.
"Increasing Access To Clinical Cancer Trials and Emerging Technologies For Minority Populations: The Native American Project." Daniel G. Petereit, et al, John T. Vucurevich Cancer Care Institute, Rapid City, South Dakota and University of Wisconsin Comprehensive Cancer Center, Madison, WI.
The Journal of Clinical Oncology is the semi-monthly peer-reviewed journal of the American Society of Clinical Oncology (ASCO), the world's leading professional society representing physicians who treat people with cancer.
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Journal of Clinical Oncology