People with certain cancers enrolled in clinical trials survive longer, not necessarily from the treatment itself but potentially because those enrolled are better off to begin with, according to new research.
"The survival benefits for an individual to be on a cancer trial are not necessarily to be on a trial itself. Cancer trials select patients who are healthier and are able to tolerate treatments," said senior study author Dr. Waddah Al-Refaie, chief of surgical oncology at MedStar Georgetown University Hospital in Washington, D.C.
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For decades, researchers have suspected that even if an experimental treatment isn't better than currently available care, clinical trials could help patients because of the close monitoring from doctors.
To determine whether clinical trials help patients regardless of treatment success, researchers examined the survival of more than 550,000 people with cancer listed in the California Cancer Registry between 2002 and 2006.
Researchers found a 26 percent decrease in the risk of death for cancer patients enrolled in clinical trials, according to research published in the Journal of the American College of Surgeons. The study did not report how many people died.
The increased survival was only seen in people with lung, colon, and breast cancers. Patients with cancer of the skin, esophagus, stomach, liver, or pancreas did not have any increase in survival, researchers found.
Participation in clinical trials was extremely low, as several other studies have noted: just a third of one percent of patients, or 1,846 people.
Clinical trial participants tended to be younger than 65 and affected by earlier stages of cancer, factors that could explain why enrollees survived longer than cancer patients who didn't pursue experimental trials.
Researchers also found that participants tended to be white, a long-held issue with clinical trials.
"This is a call to broaden the criteria of clinical trials to represent the individuals we see in the clinic: older patients, non-whites, under-insured, and sicker individuals," Al-Refaie told Reuters Health.
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However, the study didn't adequately distinguish whether trials themselves can help patients, according to Colin Begg, chair of epidemiology and biostatistics at Memorial Sloan-Kettering Cancer Center in New York.
"That's not something that's possible to do in this study," Begg, who was not involved in the current study, told Reuters Health.
Survival may not even be a good way to determine a clinical trial's benefit, according to Dr. Otis Brawley, chief medical officer of the American Cancer Society.
Increased survival doesn't mean that patients live longer with cancer, "it's that they know they have cancer for a longer period of time," Brawley told Reuters Health.
Not only do clinical trials potentially select for healthier participants, but also for more engaged and resourceful doctors.
"Doctors who participate in clinical trials are usually the folks who have a higher standard of care," said Brawley, who was not involved in the study. "They learn how to maintain higher standards through participation in clinical trials."
Clinical trials are closely monitored by experts, while standard treatments typically have no outside audits, which could impact survival.
"Even if you're not in a clinical trial, patients who talk to their doctors and spend a lot of time trying to understand their disease - it's my belief that those patients end up doing better," Brawley said.
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