We're accustomed to doctors basing the dosage of a drug on a person's body weight. It makes sense that you wouldn't give a 120-pound woman the same dosage of chemo as a 200-pound woman, even if their tumors were identical. But did you ever consider that how muscular a person is might make a difference?
Let's say you have two women who weigh the same, with identical tumors, and they're receiving identical chemo treatments. But one experiences significant side effects and the other sails through. What's going on there? A study published in Clinical Cancer Research explored that idea with respect to 5-FU (Adrucil), a chemotherapy drug commonly used in combination with other drugs to treat colon cancer.
About the Study
5-FU can cause a lot of side effects, including chest pain, confusion, diarrhea, mouth sores, nausea, and tingling in the hands and feet. Researchers decided to examine the impact that lean body mass has on the occurrence of those side effects. Lean body mass basically indicates how much of you is muscle and how much is fat.
Researchers used a CT scan to determine lean body mass in people receiving a 5-FU/Leucovorin chemo combo for stage 2 or stage 3 colon cancer.
Results of the Study
Leaner women tended to have fewer side effects when given the same chemo dosage as women with more fatty tissue. The number the researchers came up with as a threshold for developing significant side effects was 20 milligrams of 5-FU per kilogram of lean body mass.
I'm not sure what any of us can actually do with that number, but you could always mention it to your oncologist. If your chemo regimen includes 5-FU and side effects are an issue, your doctor might want to take a look at the study and decide if it's relevant for your particular treatment situation.
Related Research Summaries:- Extreme Obesity Associated with Worse Colon Cancer Prognosis
- Importance of Completing Adjuvant Chemotherapy
- Blood Test May Help Choose Best Candidates for FOLFIRI Regimen
- Chinese Herbal Medicine for Nausea
Source: Prado, C. and Baracos, V. "Body Composition as an Independent Determinant of 5-Fluorouracil–Based Chemotherapy Toxicity." Clinical Cancer Research 13 (1 Jun. 2007): 3264-3268. Accessed 2 Jun. 2007.
