New research showing widespread use of vitamins and supplements among people diagnosed with cancer suggests the need for greater communication between doctors and patients.
In a study published in the Feb. 1, 2008, issue of Journal of Clinical Oncology, researchers found that, while vitamin, mineral and dietary supplement use is extensive among cancer patients and survivors, up to 68 percent of physicians might not know that their patients are using them.
Knowing about supplement use is crucial for doctors because some products can have an adverse effect on the cancer itself or on the drugs being used to treat it. For instance, folic acid might be involved in colon cancer progression, and St. Johns Wort can interfere with chemotherapy, the researchers point out.
While many cancer patients and survivors who use supplements fail to let their doctor know of their choices, both physicians and patients “need to understand and discuss the potential concerns associated with dietary supplement use,” the researchers write.
The researchers also urge physicians to directly ask their cancer patients about supplement use and to document any use in their patients’ medical charts. They also suggest that physicians “probe” to understand their patients’ specific reasons for taking supplements – to relieve stress, for instance – and to be mindful that patients sometimes are apprehensive about mentioning their supplement use for fear of disapproval.
Funded by the National Cancer Institute, the study was conducted by researchers from Fred Hutchinson Cancer Research Center in Seattle, Washington. The researchers analyzed 32 previous studies, published between 1999 and 2006, that addressed supplement use among more than 15,000 adult cancer patients and survivors in the United States.
The purpose of the study was to quantify the prevalence of supplement use among adult cancer survivors; identify trends in vitamin use based on cancer type, time of diagnosis and other social and demographic factors; and identify future research needs.
The findings: The use of any vitamin or mineral was reported by 64 percent to 81 percent of cancer patients and survivors. The use of any multivitamins ranged from 26 percent to 77 percent.
These rates represent a significant increase over the rates of supplement use in the general population.
Between 25 percent and 33 percent of the general population use multivitamin/minerals, and more than 50 percent use dietary supplements, the researchers comment.
Three of the studies in the analysis looked at changes in supplement use after cancer was diagnosed. All three studies showed an increase of use after diagnosis.
When the researchers considered different types of cancer, they found that breast cancer patients had the highest use of multivitamins, between 57 percent and 62 percent. Use by prostate cancer patients was between 3 percent and 23 percent.
Many cancer patients and survivors report using supplements because they believe that supplements can reduce treatment side effects, decrease chances of recurrence and improve survival. Studies addressing these topics, however, are inconsistent or inconclusive.
While this study highlights the need for more research into how dietary supplements might affect cancer treatment, prevention and survival, it underscores the need for more communication between doctors and patients.
“Many of us are aware that cancer patients look to dietary supplements as a way to gain a sense of control over their health and well being,” said Robert A. Somer, M.D., an oncologist at Cooper Cancer Institute. “But without major evidence to support the use of supplements, it is extremely important that physicians talk to their patients about dietary supplements, which in some cases can be harmful.”
As an example, Dr. Somer noted that high does of antioxidants, such as vitamins C and E, can negate the impact of radiation.
“Patients must make sure their doctors are aware of the supplements they are using, and physicians should ask. There should be open communication between doctor and patient,” he said.
Dr. Somer added that, use of a multivitamin might be advisable for patients who are unable to eat healthfully during treatments due to swallowing difficulties or poor appetite. “But patients must do this under the guidance of their physician,” he said.
Of course, living a healthy lifestyle is what’s most important, said Dr. Somer. “There is more research supporting a healthy lifestyle to modify cancer risk than there is research supporting supplements to modify cancer risk.”
As part of a healthy lifestyle, Dr. Somer recommends eating a heart-healthy diet (meals that are balanced, low in fat and high in fiber), getting some exercise every day and drinking alcohol in moderation if at all.
“To maintain your health during treatment and after diagnosis, do the things that healthy people do: partake in social or recreational activities, do the things that make you happy, plan for the future. You can do more for yourself by living a healthy lifestyle than you can by taking over-the-counter supplements. Eat well, exercise, get proper rest, and change those health-robbing behaviors, such as smoking. The ‘healthier’ you live, the better you’ll feel,” Dr. Somer said.
He noted that in addition to various support-group programs available through Cooper University Hospital, Cooper’s Complementary Medicine Program offers a wide variety of mind-body-spirit therapies designed specifically for cancer patients. The program is open to anyone affected by cancer – patients, family members, caregivers – whether a patient at Cooper or not.
“These are physician-supervised, non-traditional therapies to support conventional treatment, which many patients have found extremely helpful in reducing diagnosis- and disease-related stress, anxiety and depression, and in enhancing their overall sense of well being,” Dr. Somer said.
“Our goal is to help people,” Dr. Somer added, “and we are studying and learning more every day. What this study tells us is to step up our dialogue with patients, to make sure that they tell us what supplements they are using or maybe considering using, and why. Through this dialogue, we can direct patients to other therapies proven to be beneficial and possibly prevent patients from using products that might do them more harm than good,” Dr. Somer said.
Cooper Cancer Institute
The Diane Barton Complementary Medicine Program