Risk Factors for Complications and Long-Term Outcomes Following Completion Lymph Node Dissection for Cutaneous Melanoma: A Retrospective Cohort Study.

Background: Completion lymph node dissection (CLND) for malignant melanoma is performed for regional cancer control and is associated with a high complication rate. It is unknown whether post-operative complications influence cancer recurrence or survival. Our aim was to evaluate the risk factors for short- and long-term complications after CLND, and to determine whether complications affect recurrence or survival.

Method: We performed a retrospective cohort study including all melanoma patients who underwent CLND in the Stockholm region during 2005-2014. Patient and cancer characteristics were collected from medical records, as were clinical outcomes. Assessment was performed by multivariate logistic regression.

Results: Among 144 patients, the risk of any post-operative one year complication was 68.8%. Lymphedema (41.0%), infection (37.5 %), and seroma (31.3 %) were the most common complications. Diabetes and inguinal CLND were associated with nine- and ten-fold increased risks of post-operative complications (p<0.05), respectively. Complications were linked to an increased risk of recurrent cancer (p<0.05), median follow-up time of 49 months, but did not appear to affect five-year survival.

Conclusion: Post-operative complications are common in melanoma patients undergoing CLND. Strong risk factors for complications are diabetes and inguinal CLND. Post-operative complications appear to be associated with increased risks of recurrent cancer, but the mechanism is unknown.