LOS ANGELES--The Southwest Oncology Group (SWOG) is generally doing
fine at enrolling women and African-Americans into clinical trials
but is not doing so well at enrolling elderly patients, SWOG
investigators reported at the ASCO annual meeting. SWOG
biostatistician Joseph Unger found that the elderly were
under-represented in almost every type of cancer clinical trial.
The review was inspired by a heightened concern within SWOG over
patient access to clinical trials. Kathy S. Albain, MD, professor of
medicine, Loyola University Medical Center, Chicago, is chair of
SWOGs Committee on Women and Special Populations.
In an interview with Oncology News International, she said that
"our committee was concerned with the participation of
African-Americans and with women in our trials. We also suspected
that the elderly might be underserved."
She said that SWOG did this survey "because we wanted to see
exactly where we stood with our clinical studies populations vs US
census-adjusted SEER cancer rates. What struck us is the dramatic
under-representation of the elderly. I did not expect that."
This study became possible because the National Cancer Institute
recently made data from the Surveillance, Epidemiology and End
Results (SEER) cancer registry more easily accessible. "SEER
data became publicly available online, which gave us the capability
to generate the most recent population estimates," Mr. Unger said.
SWOG vs SEER
Mr. Unger, of the Fred Hutchinson Cancer Research Center, Seattle,
and his colleagues at SWOG analyzed all registrations to SWOG
therapeutic trials between 1993 and 1996, and compared the incidence
rates of female, African-American, and elderly (65 years or older)
patients in SWOG trials with corresponding US population rates
derived from 1990 US census and 1992-1994 SEER data.
This analysis revealed that: African-Americans were neither
over-represented nor under-represented in SWOG, compared with SEER
(10.2% vs 10.1%, respectively).
Women were generally well represented (SWOG 41% vs SEER 43%). Women
were under-represented in colorectal, head and neck, and lymphoma studies.
Patients age 65 and over were substantially under-represented in all
cancer studies except lymphoma. "The overall rate for SWOG was
25%, compared with 63% for the US cancer population," Mr. Unger said.
In the more common cancers, he said, the differences between the SWOG
and US population rates include 9% vs 49% in breast cancer, 41% vs
72% in colorectal cancer, 27% vs 63% in leukemia, and 39% vs 66% in
"These findings suggest that the elderly are currently an
under-served population in cancer clinical trials," Mr. Unger
said. "In common cancers, new initiatives to better accommodate
the elderly should be considered."
Many Factors May Contribute
There are many factors contributing to the underaccrual of elderly
patients. Some researchers have suspected that problems with Medicare
reimbursement for some aspects of treatment of patients on clinical
trials might be one major cause for the low representation of elderly
patients, but the National Cancer Institute of Canada, where all such
expenses are paid, has noted a similar under-representation of older
patients in clinical studies.
"We need prospective studies on both the patient barriers and
the physician barriers to participation of older patients in clinical
trials," Dr. Albain said.
The National Institute on Aging, in conjunction with the National
Cancer Institute, plans in the near future to issue a Request for
Proposals (RFP) to study the factors responsible for the low
participation of older patients in cancer clinical trials.