Obesity may prevent chemotherapy drug from working, finds study

The effectiveness of chemotherapy may be drastically reduced in obese patients as fat cells interfere with the drug, a pioneering new study has shown.

Researchers found adipocytes, or fat cells, can absorb and metabolise the drug used in chemotherapy, daunorubicin, drastically reducing its effectiveness and negatively impacting treatment outcomes.

Previous research found obese patients were more likely to suffer from poorer prognosis for certain cancers, including breast, colon, ovarian, and prostate.

Other research had also indicated a higher proportion of fatty tissues could effect the way chemotherapy drugs are absorbed, metabolised and excreted.

But the study published in the journal Molecular Cancer Research of the American Association for Cancer Research is the first of its kind to find fatty tissues both interact with the way the drug is absorbed and excreted while also reducing its overall effectiveness.

Author Steven Mittelman, associate professor of paediatrics and the division chief of paediatric endocrinology at UCLA Mattel Children’s Hospital in Los Angeles, said the results were “surprising”.

“The finding that human fat cells can metabolise and inactivate a chemotherapy is novel and surprising,” he said. “This is important for leukemia and a lot of other cancers that grow in the bone marrow or around fat cells, since that means that fat cells might remove chemotherapy from the environment and allow the cancer cells to survive.”

Fellow author Etan Orgel, attending physician at Children’s Hospital Los Angeles and assistant professor of clinical paediatrics at the Keck School of Medicine at the University of Southern California, said the findings indicated a need for further research.

“A deeper understanding of the process could lead clinicians to deliver more effective treatment by choosing or designing chemotherapy drugs that are more resistant to the enzymes in fat cells,” he said.