Overweight and obese women who had surgery plus radiation therapy to treat breast cancer, and who had 12 or more lymph nodes removed, were more likely to develop lymphedema than women of normal weight, an analysis showed.
Published in the Journal of Cancer Survivorship, the analysis was based on data collected from 2,425 participants enrolled in the Women’s Healthy Eating and Living (WHEL) study. The original study examined the effect of a plant-based diet on rates of breast cancer return and death among women with early-stage disease.
Background of Study
Lymphedema is a chronic side effect of some breast cancer treatments in which lymph fluid collects in tissues and can cause pain, swelling, and infection on the side of the body where surgery was performed or that received radiation.
Reports vary, but researchers estimate between 6 and 30 percent of women develop lymphedema, either soon after treatment or years later.
Through their analysis, the researchers of the current study wanted to find out whether certain traits among participants could predict which women would develop the condition.
The researchers examined previously-collected data from the 83 percent of WHEL participants who reported lymphedema status. The women had stages I-IIIA breast cancer and received treatment at seven sites in California, Arizona, Oregon, and Texas between 1995 and 2000. They entered the study within 4 years of diagnosis. All had axillary lymph node dissection, surgery to remove multiple lymph nodes in the armpit.
For this analysis, the researchers examined participants’ answers to survey questions when they entered the study and at one other time between 2003 and 2006, when WHEL researchers asked women whether
- a healthcare provider had told them they had lymphedema
- they remembered a time their arms and hands were different sizes from one another
Other factors that could contribute to lymphedema risk were considered, such as number of lymph nodes removed, type of surgery (lumpectomy or mastectomy), type of treatment (chemotherapy and/or radiation therapy) and body mass index, or BMI, which uses a person’s height and weight to assess body fat.
Overall, 676 participants, or about 28 percent, reported lymphedema. Comparing this group to the group that did not report lymphedema, the researchers found:
- Overweight women—those with a BMI greater than 25 (equivalent to a 5’6” woman of 155 pounds) — were 33 percent more likely to develop lymphedema than women with lower BMIs; the chances were higher in women considered obese, with a BMI greater than 30 (equivalent to a 5’6’’ woman of 186 pounds).
- Women who had 16 or more lymph nodes removed had a 65 percent higher chance of developing lymphedema than those who had 10 or fewer taken, regardless of type of breast cancer surgery
- Radiation therapy, when given after any breast cancer surgery, increased the risk for developing lymphedema
These findings suggest that women who have many lymph nodes removed and who are also overweight or obese may have the greatest risk of developing lymphedema.
Limitations of the Study
Lymphedema status was based on personal reports, which could over- or underestimate cases. Also, the researchers only knew the women’s BMI after diagnosis, so they could not measure its impact before treatment.
The participants themselves may not represent the average woman with breast cancer. Most were non-Hispanic White, with an average age of 51 at diagnosis. More than half (55.3%) were overweight or obese.
What This Means for You
Doing what you can to manage your weight could lessen your chances of developing lymphedema, these findings suggest. But losing weight is not easy. Talk with your providers for suggestions, such as seeing a nutritionist, or starting or resuming an exercise program.
The nature of the breast cancer determines some of your risk factors, such as number of lymph nodes removed. When the WHEL study was conducted, axillary lymph node dissection was standard of care. Today, many women undergo sentinel lymph node biopsy, which removes only the first lymph nodes the cancer is likely to reach and lessens the risk of developing lymphedema. Ask your surgeon to explain which surgery you need.
Dominick, SA, Madlensky L, Natarajan L, Pierce JP. Risk factors associated with breast cancer-related lymphedema in the WHEL Study. Journal of Cancer Survivorship; 2013;7(1):115-123.