The prognostic relevance of primary tumor sidedness to surgical treatment for recurrent colon cancer

Purpose The aim of this study was to investigate the predictive relevance of tumor sidedness on surgical resection after recurrence by evaluating the treatment outcomes after primary resection and recurrence in patients with localized colon cancer (CC). Methods A total of 735 consecutive patients who underwent curative resection for Stage I–III CC from 1997 to 2013 were categorized as having either right- or left-sided CC, and survival after primary surgery and after recurrence were analyzed. Results A total of 104 patients (14.1%) developed recurrence, 94 of which were in a single organ, and 59 patients underwent curative resection. For recurrence from both sides of the colon, a significantly better 5-year overall survival (OS) was experienced by patients who underwent curative resection compared to those who received palliative treatment (right: 42.2% vs not reached, respectively; P < 0.001; left: 71 vs 15.9%, respectively; P < 0.001). Meanwhile, a still worse OS was observed in patients with curative resection for recurrent right-sided CC compared to those with resection for recurrent left-sided CC (5-year: 42.2 vs 71%; P = 0.03). Conclusion Surgical resection undoubtedly improved survival after recurrence, however, patients with surgical resection for recurrent right-sided CC tended to have a worse prognosis.