Breast cancer patients, who are overweight or obese, might benefit less from treatment with docetaxel, a common chemotherapy drug, than lean patients, warn researchers. It is not widely known, but obese women have a higher risk of getting breast cancer and obese patients have a higher risk of relapsing.
Moreover, while many cancer patients are overweight or obese, the efficacy of anti-cancer drugs according to their body mass index (BMI) is generally not known.
"Docetaxel is a lipophilic drug, suggesting that fat present in the body could absorb part of the drug before it can reach the tumour," Christine Desmedt from the KU Leuven Laboratory for Translational Breast Cancer Research in Belgium, explained.
For the current study, published in the Journal of Clinical Oncology, the research team analysed data from a clinical trial with over 2,800 breast cancer patients that started around the turn of the millennium.
Patient data was collected over the course of more than ten years. The patients in the trial were treated with a combination of chemotherapy drugs with or without docetaxel, one of the most widely used chemotherapy drugs in the world
The researchers then looked at how many patients relapsed and how many had passed away. Their statistical analysis of the data shows that overweight and obese patients who received docetaxel as part of their treatment had poorer outcomes than lean patients. The results raise concerns about treating overweight and obese cancer patients with docetaxel.
"If follow-up research confirms that this finding is solely related to the pharmacological characteristics of docetaxel, this might also apply to patients with other cancer types that are treated with docetaxel, such as prostate or lung cancer," Desmedt said. "These results also make us wonder whether other chemotherapy drugs from the same family, like paclitaxel, will show the same effect."
The researchers said that more research is needed before changes in treatment can be implemented. Patients who have concerns about docetaxel can discuss these with their doctor.