Robotic approach may be associated with a lower risk of lung metastases compared to laparoscopic approach for mid-low...

Describe differences on recurrence patterns of mid-low rectal cancers treated with neoadjuvant chemoradiotherapy and low anterior resection between laparoscopic and robotic approach.

Patients were identified from a prospectively maintained institutional database between 2006 and 2019. Demographics, clinicopathological features, recurrence, and survival were investigated. Cox regression analysis was performed for risk factor analysis.

A total of 160 patients (36 laparoscopic and 124 robotic) were included. Systemic recurrence rate was higher in laparoscopic group (27.8 vs 12.1%, p = 0.023). Liver recurrence was similar (11.1 vs 4.0%). Lung recurrence was higher after laparoscopy (19.4 vs 6.5%, p = 0.019). Time to lung recurrence was shorter after laparoscopy (13.0 months, IQR 4.0-20.0) compared to robotic (23.5 months, IQR 17.0-42.7) with no statistical significance. Time to liver recurrence was similar between laparoscopy (19.5 months, IQR 4.7-37.5) and robotic (19.0 months, IQR 10.5-33.0). Median overall survival after lung recurrence was different (p = 0.021) between laparoscopy (19.0 months, IQR 16.0-67.0) and robotic (74.0 months, IQR 50.2-112.2). OS after liver recurrence was similar between groups. Overall survival and lung disease-free survival were different between the two groups (p = 0.032 and p = 0.020), while liver disease-free survival and local recurrence-free survival were not. Laparoscopy (p = 0.030; HR 3.074, 95% CI: 1.112-8.496) was a risk factor for lung disease-free survival on multivariate analysis.

Lung recurrences were less frequent and with better overall survival in the robotic group. Liver recurrences were not influenced by choice of approach. Trials are needed to investigate why the robotic approach affects distant metastasis control.