The use of laparoscopy for T4a and T4b colon cancer: are we playing with fire?

Background The laparoscopic approach for colon cancer has become widely accepted. However, its safety for T4 tumors, and particularly for T4b tumors when local invasion to adjacent structures occurs, remains controversial. This study aimed to compare short and long-term outcomes in patients undergoing laparoscopic vs. open resection for T4a and T4b colon cancers. Methods A prospectively maintained, single-institution database was queried to identify patients with pathological stage T4a and T4b colon adenocarcinomas electively operated on between 2000 and 2012. Patients were divided into two groups based on the use of laparoscopy. Patient characteristics, perioperative, and oncologic outcomes were compared. Results One hundred and nineteen patients [41 laparoscopic (L), 78 open surgeries (O)] met the inclusion criteria. No difference was observed in age, gender, BMI, ASA, and procedure between groups. Tumors treated by L were smaller than O ( p = 0.003). No difference was observed in morbidity, mortality, reoperation, or readmission between the groups. Length of hospital stay was shorter in L than O (6 vs. 9 days, p = 0.005). Conversion to open was necessary in 22% of all T4 tumors laparoscopic cases. However, when tumors were subdivided by pT4 classification, conversion was necessary for 4 of 34 (12%) pT4a patients vs. 5 of 7 (71%) pT4b patients ( p = 0.003). In the pT4b cohort ( n = 37), more tumors were treated by the open approach (30 vs. 7). For pT4b tumors, the R0 resection rate was 94% (86% in L vs. 97% in O, p = 0.249). The use of laparoscopy did not impact overall survival, disease-free survival, cancer-specific survival, or tumor recurrence overall in all T4 or T4a and T4b tumors. Conclusions Laparoscopic surgery can be safely performed in pT4 tumors with similar oncologic outcomes as compared to open surgery. However, for pT4b tumors, the conversion rate is very high. The open approach may be preferable.