Breast Cancer and Obesity
According to the March 15 Journal of Clinical Cancer Research, a journal of the American Association for Cancer Research, women who are overweight or obese have a lower breast cancer survival rate and the cancer appears to be more aggressive.
According to the researchers who conducted the study published in the above mentioned journal, “We are learning that the fat tissue may increase inflammation that leads to more aggressive disease”. The researchers conducted a study of 606 women with locally advanced breast cancer who were also classified by body mass index. Overweight was defined as 24.9 or above and obese was defined as greater than 30.
What they found was an overall survival rate at five years of follow-up of 56.8% among obese women, 56.3% among overweight women and a 67.4% rate among normal weight women. The researchers then followed this cohort of women for ten years and found a surprising result. The survival rate among obese women was only 42.7%, among overweight women only 41.8 %, but with normal weight women the survival rate was a whopping 56.5% of the women studied.
The rate of inflammatory breast cancer, as opposed to the less-aggressive non-inflammatory breast cancer showed even worse outcomes. Among obese women survival rates were 45% as opposed to 30% in overweight women and 15% in normal weight women.
Recurrence was also noted to be higher in women with higher BMIs. By five years, 50.8 percent of obese women reported a recurrence compared to the 38.5 percent of overweight women. Normal women again trailed behind in recurrence by 38.5%. By ten years the rate of recurrence was 58% among obese women and 45.4 percent among normal weight women with a normal BMI.
Worsening the picture is that breast cancer is frequently treated with tamoxifen, which tends to cause weight gain in its patients. The role of the dietitian is to work with this group of women in particular to keep their weight down while taking this drug. A question left unanswered in this study is if women who are overweight or obese lose weight during treatment, does survival rate increase???
About the Author
Kathy Shattler received her Master of Science degree from Michigan State University in E. Lansing Michigan in Human Nutrition. Her twenty-two years of practice includes holding positions as a Lecturer, Chief Clinical Dietitian and Program Manager. Kathy is the Founder of Nutri-Care Consulting and is currently the Nutrition Director of www.CEU4U.COM, an online continuing education management company for Registered Dietitians and Dietetic Technicians.
