Laparoscopic surgical challenge for T4a colon cancer.

For patients with T4a colon cancer, the risk of peritoneal dissemination after surgery remains unclear. Seven hundred and eleven patients with T3 or T4a colon cancer, 80 years of age or younger, underwent curative resection (open surgery in 512 and laparoscopic surgery in 199) at the four Jikei University hospitals between 2006 and 2012. Their risk factors for peritoneal dissemination after surgery were evaluated retrospectively. Number of lymph node metastases, postoperative liver metastases and postoperative peritoneal dissemination events in the T4a group were significantly greater than the number in the T3 group. Peritoneal dissemination after surgery developed in four patients (0.7%) in the T3 group and in six patients (5%) in the T4a group. Risk factors for peritoneal dissemination consisted of macroscopic type ( = 0.016), serosal invasion ( = 0.017) and number of lymph node metastases ( = 0.009) according to the Cox proportional hazards regression model. However, tumor diameter and surgical approach (laparoscopic open) were not significant factors for peritoneal dissemination. There were no significant differences between the postoperative relapse-free survival rates for each surgical approach within the T3 or T4a group. Because of comparable postoperative peritoneal dissemination in T3 and T4a colon cancer by the surgical approach (laparoscopic or open), laparoscopic surgery for patients with T4a colon cancer seems justified.