Details emerge in link between body mass index, chemotherapy response

MD Anderson researchers discussed new data on the connection between body mass index (BMI) and response to presurgical chemotherapy in patients with inflammatory breast cancer during a poster discussion at the 36th annual CTRC-AACR San Antonio Breast Cancer Symposium.

The study examined 1,002 cases of patients with inflammatory breast cancer or locally advanced non-inflammatory breast cancer between 2006-2012. It was the first to assess BMI association only in stage III locally advanced breast cancer, which includes inflammatory breast cancer, in contrast to previous research performed in early breast cancer for pathological complete response and survival outcome prediction.

BMI data was collected at breast cancer diagnosis and at the last cycle of chemotherapy and researchers compared the change in BMI value over the course of treatment.

Led by postdoctoral fellow Takahiro Kogawa, M.D., Ph.D., and Naoto T. Ueno, M.D., Ph.D., and Richard Theriault, D.O., both professors of Breast Medical Oncology, the study found an increase in BMI was associated with improved pathological complete response, especially in patients with normal BMI, a discovery that surprised researchers.

"This was a complete surprise because it goes against what we've known for a while that increased weight is often a negative factor," Ueno said. "However, it's not conclusive at this point and we'll need to evaluate the data more carefully in addition to follow-up prospective studies." The researchers didn't analyze data on patients' quality of life or adverse events during treatment, so couldn't say whether weight gain during treatment might potentially be a good sign.

The investigation took shape after researchers recognized an absence of data relating to body weight changes during chemotherapy and whether these changes might impact treatment.

According to the Centers for Disease Control and Prevention, nearly one-third of adult Americans (35.7%) are classified as obese. The rising obesity rates, often considered a public health epidemic, are also of great importance to oncologists because of established links between a high BMI and one's cancer risk, outcomes and treatment options.

Ueno said being able to better understand the prognosis of patients with a high BMI, and albeit a different topic, predicting the outcomes of this group, will be an important area of follow-up research.

The study was conducted through grant support from the Morgan Welch Inflammatory Breast Cancer Research Program and the State of Texas Rare and Aggressive Breast Cancer Research Program.