Intensified surveillance after surgery for colorectal cancer significantly improves survival

BACKGROUND Postoperative surveillance after curative resection for colorectal cancer has been demonstrated to improve survival. It remains unknown however, whether intensified surveillance provides a significant benefit regarding outcome and survival. This study was aimed at comparing different surveillance strategies regarding their effect on long-term outcome. METHODS Between 1990 and 2006, all curative resections for colorectal cancer were selected from our prospective colorectal cancer database. All patients were offered to follow our institution's surveillance program according to the ASCO guidelines. We defined surveillance as "intensive" in cases where >70% appointments were attended and the program was completed. As "minimal" we defined surveillance with <70% of the appointments attended and an incomplete program. As "none" we defined the group which did not take part in any surveillance. RESULTS Out of 1469 patients 858 patients underwent "intensive", 297 "minimal" and 314 "none" surveillance. The three groups were well balanced regarding biographical data and tumor characteristics. The 5-year survival rates were 79% (intensive), 76% (minimal) and 54% (none) (OR 1.480, (95% CI 1.135-1.929); p <0.0001), respectively. The 10-year survival rates were 65% (intensive), 50% (minimal) and 31% (none) (p <0.0001), respectively. With a median follow-up of 70 months the median time of survival was 191 months (intensive), 116 months (minimal) and 66 months (none) (p <0.0001). After recurrence, the 5-year survival rates were 32% (intensive, p = 0.034), 13% (minimal, p = 0.001) and 19% (none, p = 0.614). The median time of survival after recurrence was 31 months (intensive, p <0.0001), 21 months (minimal, p <0.0001) and 16 month (none, p <0.0001) respectively. CONCLUSION Intensive surveillance after curative resection of colorectal cancer improves survival. In cases of recurrent disease, intensive surveillance has a positive impact on patients' prognosis. Large randomized, multicenter trials are needed to substantiate these results.