AT SABCS 2014
SAN ANTONIO– (FRONTLINE MEDICAL NEWS) – Breast cancer patients are often advised that in order to avoid developing lymphedema they should shun blood pressure cuffs, injections, and blood draws on their at-risk arm as well as airplane travel unless wearing a compression sleeve.
All these recommendations are anecdotally based. None withstood formal evaluation in a prospective study of 710 breast cancer patients with 860 treated and thus potentially at-risk breasts, Chantal M. Ferguson reported at the San Antonio Breast Cancer Symposium.
“Our findings don’t support current guidelines regarding these activities and suggest that further studies are needed to determine if these guidelines are appropriate,” said Ms. Ferguson of Massachusetts General Hospital, Boston.
Standard practice for newly diagnosed breast cancer patients at Mass. General is to enter into a prospective screening program for lymphedema, a chronic, painful swelling caused by damage to the lymphatic system secondary to breast cancer therapy.
Breast cancer patients routinely have bilateral arm volume measurements taken using a perometer preoperatively, postoperatively, after finishing chemotherapy and radiotherapy, and at 3- to 7-month intervals thereafter following completion of treatment. At each measurement, data are collected on exposures to airplane flights, blood pressure readings, and the other often-cited putative risk factors.
The incidence of lymphedema among the 710 patients in the study at 24 months was 7.05%. The diagnosis required at least a 10% increase in arm volume, compared with the untreated side. For women who underwent bilateral breast surgery, a weight-adjusted volume change formula was employed.
Consistent with the medical literature, axial lymph node dissection and a higher preoperative body mass index were significantly associated with the development of lymphedema. So was self-reported trauma to the at-risk arm, although the reported trauma ranged in severity from bruises to fractures in motor vehicle accidents.
Session cochair Dr. Michelle E. Melisko observed that few medical oncologists are well informed about lymphedema or the numerous and highly complex functions of the lymphatic system, so she was favorably impressed that physicians at Mass. General have incorporated structured screening for the disorder as part of the institutional standard of care.
She cautioned, however, that rates of the risk factor events under study were relatively low. For example, only 17% of the breast cancer patients had one or more blood pressure measurements taken on their at-risk arm during 2 years of prospective follow-up, 9% had one or more blood draws, and 15% of patients flew for a total of 12 hours or more.
“I’m not sure that we can take these data to say we can let patients go hog wild and get their blood pressure measured all the time on that arm. This is a large prospective trial featuring a broad range of patient ages and BMIs, and both lumpectomy and mastectomy patients, and the trial adds a lot to the literature, but it does need to be interpreted with caution,” said Dr. Melisko of the University of California, San Francisco.
The study was funded by the National Cancer Institute and the Adele McKinnon Research Fund for Breast Cancer–related Lymphedema. Ms. Ferguson reported having no financial conflicts.