Breast cancer patients who are either obese or poorly educated are more likely to get lower-than-optimal doses of chemotherapy, U.S. researchers reported on Thursday.
The finding, published in the Journal of Clinical Oncology, may help explain why some women relapse and others do not, despite the availability of good treatments for the disease.
The problem appears to be with doctors who mean well and want to avoid causing side effects in their patients, the team at the University of Rochester Medical Center in New York found.
The researchers suggest that doctors are underdosing obese patients, for instance, out of concern that a larger dose based on their weight would mean worse side effects. But there's no evidence that's true.
And when it comes to socioeconomic status, researchers suggest that doctors are making assumptions that a less-educated patient might be less willing to stick with a tough course of treatment
“Simply put, this evidence shows that doctors are likely to reduce the chemotherapy levels for these women, even though there is no solid medical basis to do it,” said Dr. Gary Lyman, who led the study.
They looked at the records of 764 women treated for breast cancer between 2002 and 2005 at 115 randomly selected, private oncology practices around the country.
They found that severely obese women were four times more likely to get less chemotherapy than they need. Women with less than a high-school education were three times more likely to be underdosed. And women who live in the South were almost six times more likely to get shorted on the life-saving drugs.
Bioethicist Dr. Annette Dula says this type of health care disparity is a big problem.
"I don't know how doctors can put themselves in the shoes of some of their patients that aren't like them and I think that's part of what needs to happen," she said.
“We have new therapies and cures out there for many forms of cancer and sadly, sometimes we’re not curing people because they are not getting the full doses that should be standard,” Lyman said in a statement.
Don't miss these Health stories
More women opting for preventive mastectomy - but should they be?
- Larry Page's damaged vocal cords: Treatment comes with trade-offs
- Report questioning salt guidelines riles heart experts
- CDC: 2012 was deadliest year for West Nile in US
- What stresses moms most? Themselves, survey says
- More women opting for preventive mastectomy - but should they be?
Handpicked docs do better
A second study in the same journal found women who carefully chose their own breast cancer surgeon tended to get more experienced surgeons and care at specialized centers, compared to women referred by another doctor or their health plan.
The team at the University of Michigan Comprehensive Cancer Center examined the cases of 1,844 women recently diagnosed with breast cancer in Detroit and Los Angeles.
More than 60 percent of the patients said they were referred to their surgeon by another doctor, and 15 percent were referred by their health plans. About 25 percent chose their surgeon based on reputation.
Women with more education and higher incomes were more likely to have chosen their own surgeon.
Evidence shows that patients who choose any type of doctor based on their experience tend to do better. For surgery, patients recover better if they choose a hospital or clinic where the operation is performed frequently.
“Women with breast cancer should be aware that referrals from another doctor or their health plan may not connect them with the most experienced surgeons or the most comprehensive practice settings in their community,” said Dr. Steven Katz, who led the Michigan study.
“Patients might consider seeking a second opinion, especially if they are advised to undergo a particular treatment without a full discussion of the options.”
NBC Chief Medical Editor Nancy Synderman and Reuters contributed to this report.
© 2013 msnbc.com