Risk of breast cancer recurrence in patients receiving manual lymphatic drainage: a hospital-based cohort study

BACKGROUND This retrospective cohort study evaluated whether manual lymphatic drainage (MLD) therapy increases the risk of recurrence of breast cancer. METHODS We analyzed 1,106 women who were diagnosed with stage 0-3 breast cancer between 2007 and 2011 and experienced remission after surgery and adjuvant therapy. The patients were divided into two groups: group A (n=996), in which patients did not participate in any MLD therapy, regardless of whether they developed breast cancer-related lymphedema (BCRL) after cancer treatment; and group B (n=110), in which patients participated in MLD therapy for BCRL. All patients were monitored until October 2013 to determine whether breast cancer recurrence developed, including local or regional recurrence and distant metastasis. Patients who developed cancer recurrence prior to MLD therapy were excluded from analysis. Risk factors associated with cancer recurrence were evaluated using Cox proportional hazards models. RESULTS During the monitoring period, 166 patients (15.0%) developed cancer recurrence, including 154 (15.5%) in group A and 12 (10.9%) in group B. The median period from surgery to cancer recurrence was 1.85 (interquartile range 1.18-2.93) years. Independent risk factors for cancer recurrence were tumor histological grading of grade 3, high number (≥3) of axillary lymph node invasion, and a large tumor size (>5 cm). Factors protecting against recurrence were positive progesterone receptor status and receiving radiation therapy. Receiving MLD therapy was not an outcome factor in multivariate analyses (hazard ratio 0.71, 95% confidence interval 0.39-1.29, P=0.259). CONCLUSION MLD is a gentle procedure that does not increase the risk of breast cancer recurrence in patients who develop BCRL.