Women with breast cancer face new lymphedema risk factors

I have written multiple blogs about lymphedema because it is always an important topic and because we don't know enough about it. For a long time, we have been told that women who have the greatest risk of developing lymphedema are women who have had a full axillary dissection (as opposed to a sentinel node dissection) and radiation therapy. Are there other factors that increase risk?

The numbers about the prevalence of lymphedema vary enormously. A commonly used statistic is that the risk for women who have only a lumpectomy is 1-3% while the risk for women who have a mastectomy and full axillary node dissection and radiation therapy is as high as 65-75%. You can find any number of other statistics, and there seems to be no agreement about which are correct. I have worked with surgeons who insisted that "none of my patients ever get lymphedema" even while I have personally known several who did. As far as I know, there is no suggestion that surgical skill is in any way associated with lymphedema risk, but I guess those surgeons disagreed.

Women fear lymphedema because of its chronic, progressive nature and the reality that there is no cure. There is also not a limited time of risk. Women can develop lymphedema at any time, so that being five or ten years post surgery does not bring a promise of safety. Overall, 80-90% of all women who will eventually develop lymphedema do so in the first three years, but the others can have it happen anytime.

The National Lymphedema Network has a very complete website, a great deal of information, and an annual conference that is packed with information. This is a good place to learn more if you are interested. BIDMC has a Lymphedema Center that offers treatment both to prevent and treat the problem.

But I digress. The topic at hand is that a new study, published in JAMA Surgery, looked at 486 women who had been treated for breast cancer and identified two more possible risk factors. Women who were obese and/or who received adjuvant chemotherapy that lasted for more than 144 days were more likely to develop lymphedema. Women who had more than 30 lymph nodes removed were at higher risk, and women, in that group, who had positive lymph nodes were even more likely to be affected.

Learning now that weight and duration of chemotherapy may increase lymphedema risk does not really help us in a practical way. It is heartening that attention continues to be paid to this problem, and that more information is slowly coming.