Although some doctors intentionally underdose their obese cancer patient in an effort to avoid the toxic side effects of chemotherapy drugs, that treatment strategy could actually be putting patients at risk.
"Physicians need to realize that there have been many studies that show that full correct doses have no more side effects [than reduced doses]," said Lyman.
"If you underdose the patients, as happens often, their survival is worsened."
One of the reasons for underdosing those with less education relates to their socioeconomic status and the reduced ability to get proper care.
"It's hard to make a conjecture based just on the data we have," said study co-author Eva Culakova, statistician at the University of Rochester Medical Center. "But the socioeconomic level is one of the factors."
"We speculate that physicians have concerns about a patient's ability to tolerate the side effects of chemotherapy and that the physician's uncertainty about a patient's tolerance increases with increasing social distance," said study author Dr. Jennifer Griggs, Associate Professor of Internal at the University of Michigan School of Medicine.
In other words, since physicians in these cases are not on the same social level as their patients, they may make assumptions about the patient's ability to handle the costs and inconveniences of treatment or other factors.
"One might just as well ask why we are willing to give full doses to someone with more education," Griggs said. "It may be that negotiating side effects and continued doses of treatment is easier when there is more shared culture.
"Physicians, driven by a benevolent desire to take the best care of their patient, may view those with less resources as being more vulnerable."
The fact that cancer treatment is challenging for all patients on many other levels also plays a role. And being poor does not help.
"Treatment is a difficult thing," said Lyman. "Patients who are challenged by the system are often the ones that don't have the resources or support system to help them to get through this.
"I don't doubt that among the factors that influence delivery of care is being able to afford it, take time off from work, get to treatment and have family support," he said.
And economic factors prevent some poor patients from even getting treatment. Standard chemotherapy can cost hundreds of dollars a month and can be as high as $4,400 per month for some drugs. But other costs are also involved.
"There are a lot of costs that poor patients can't pay for outside of direct drug and doctor costs," said Lyman.
The best solution to the problem may be more open communication between doctors and their patients.
"My advice is that it is extremely important for patients starting a treatment program to be very open and engaged with their doctors," said Lyman.
"Many women worry about side effects and tell their doctors, 'Don't give me too much chemo,'" said Dr. Marisa Weiss, President and Founder of BreastCancer.org. "Patients need to keep in mind that if you are going to get chemo, you want to get the best quality chemotherapy possible."
Physicians also need to be familiar with the best treatments available and help less educated patients navigate the system.
"Open discussion by all parties of the issue is the way to address this," said Hudis.
"The doctor needs reassurance that the patient understands the need for treatment and the patient needs reassurance that the doctor... with good intentions... is not compromising treatment."