A recent study shows a connection that overweight women diagnosed with cancer are more likely to have a relapse and die compared to leaner women.
The study was presented at the 8th European Breast Cancer conference (EBCC-8) in Vienna by Dr. Jennifer Ligibel.
It showed there was a 17 per cent increase in the risk of the disease returning after the initial treatment as well as the increased risk of death. This is compared with women who also suffered from the disease but were considered to be at a healthier weight. It also showed there was an extra eight per cent risk for overweight women compared to leaner patients.
This study discovered there is not a connection between overweight women being under treated due to their weight. Before this study, it was suspected that overweight women were not receiving the correct dosage of medicine and they were receiving the same amounts as leaner women. The study, that looked at almost 2,000 patients between 1997 and 1999, showed that the doctors were in fact adjusting the medication to fit the patients weight.
Dr. Jennifer Ligibel, an oncologist at Harvard Medical School, and her colleagues set up the study to examine the different doses of chemotherapy in patients where cancer cells were found in the lymph nodes. Finding cells in the lymph nodes means there is a higher risk of the cancer returning after surgery.
The research team took each patients height and weight from records and placed them into categories according to the body mass index (BMI). For a person to be considered underweight they would have a BMI of 18.5 or lower, 18.6 to 24.9 is normal, 25-29.9 is overweight and 30 or greater is obese.
They found that one-third of patients were considered within the healthy weight range, one-third were overweight, one-third obese and one per cent underweight. They also cross-examined each patients relapse-free survival and overall survival after 11 years. From that they found that a woman within the healthy weight range had a 77 per cent chance of surviving for 10 years, compared to the 70 per cent chance an overweight and obese woman had. When looking at the chances of a woman relapsing, overweight and obese women had a 34 to 35 per cent chance compared to the leaner women who had a 29 per cent chance.
The study also found for every one unit increase on the BMI scale there was a 1.5 per cent increased risk. This meant that for an overweight woman, she would have an 8 per cent increase and an obese woman would increase her risk to at least 17 per cent.
American researchers believe higher insulin levels in overweight women could be responsible for the difference in outcome. Further investigation is needed, they say, to be able to determine if losing weight after treatment will increase the chances of surviving the disease.