Prophylactic Lymphovenous Anastomosis Performed during Complete Lymphadenectomy Does Not Increase Risk of Distant Metastasis

Abstract

BACKGROUND: Lymphovenous bypass (LVB) is the preferred surgical treatment for extremity lymphedema after complete lymph node dissection (CLND). Prophylactic LVB is most frequently performed after CLND for malignancies including breast, gynecologic, and skin cancers. A serious concern with LVB is facilitation of cancer metastasis. PURPOSE: The purpose of this study was to compare rates of distant-metastasis free survival (DMFS) and relapse-free survival (RFS) between patients who underwent LVB during CLND for grossly metastatic disease and patients who underwent CLND only. To our knowledge, this is the first prospective study to evaluate the impact of prophylactic LVB on DMFS and RFS in cancer. METHODS: This is a prospective review of skin cancer patients who underwent axillary/inguinal CLND with or without LVB, between 2014 and 2020. To reduce inter-surgeon differences, all cases were performed by a single, high-volume surgeon at a tertiary hospital. Patients were excluded if they had non-melanoma cancers, stage IV disease before CLND, or follow-up time <180 days. Each LVB patient matched with a control patient based on follow-up times and cancer stage. Collected data include patient demographics, recurrence rate, immunotherapy status, and follow-up time. RESULTS: A total of 79 patients were reviewed. Fifty-two patients had various skin cancers and underwent prophylactic LVB after CLND (LVB group). Among all LVB patients, 42 had melanomas, and among them, 27 met inclusion criteria. Likewise, 27 patients who underwent CLND only (control group) were also included in this study. The two groups were similar in age, sex, follow-up time, and total nodes removed during CLND. Follow-up times were on average 16.24 ± 6.92 and 18.14 ± 9.41 months for the LVB and control groups, respectively (P = 0.40). Average number of lymph nodes removed during CLND were 16.41 ± 9.57 and 17.46 ± 15.43 in the LVB and control groups, respectively (P = 0.71). The LVB group had larger metastatic tumors in lymph nodes at 36.05 ± 40.91 mm compared with the control group at 4.40 ± 7.22 mm (P = 0.0021). The LVB group had lower rates of lymphedema at 41% compared with the control group at 85% (P = 0.0007). There were no differences in DMFS (P = 0.26) and RFS (P = 0.21) between the LVB and control groups based on Kaplan-Meier curves of survival outcomes within 1.5 years (547 days) of treatment. Melanoma recurrence rates were 48% in the LVB group and 37% in the control group (P = 0.41). Immunotherapy usage was more common in the LVB group at 92.59% compared with the control group at 59.26% (P = 0.0042). Rates of failed immunotherapy (ie, melanoma progression or recurrence during treatment) were 56% and 50% for the LVB and control groups, respectively (P = 0.71). Patients who failed immunotherapy had higher rates of melanoma recurrence at 86.36% than patients who did not at 26.32% (P < 0.0001). CONCLUSIONS: Prophylactic LVB during CLND does not impact DMFS and RFS in melanoma, which is potentially applicable to all cancers considering the extremely aggressive nature of melanoma. LVB is highly efficacious in treating lymphedema, especially given that the LVB group had considerably larger tumors in affected lymph nodes.