Oncological outcome after incidental perforation in radical rectal cancer surgery

Identification of risk factors of poor oncological outcome in rectal cancer surgery is of utmost importance. This study examines the impact of incidental perforation on the oncological outcome. Using the Swedish Rectal Cancer Registry, patients were selected who received major abdominal surgery for rectal cancer between 1995 and 1997 with registered incidental perforation. A control group was also selected for analysis of the oncological outcome after 5-year follow-up. Multivariate analysis was performed. Registry data were validated, and additional data were supplemented from medical records. After validation and exclusion of non-radically operated patients, 118 patients with incidental perforation and 155 controls in TNM stages I-III were included in the analysis. The rate of local recurrence (LR) [20% (23/118) vs. 8% (12/155) (p = 0.007)] was significantly higher among patients with perforation, whereas the rates of distant metastasis [27% (32/118) vs. 21% (33/155) (p = 0.33)] and overall recurrence (OAR) [35% (41/118) vs. 25% (38/155) (p = 0.087)] were not significantly different between the groups. Overall as well as cancer-specific 5-year survival rates were significantly reduced for the patients with perforation [44 vs. 64% (p = 0.002) and 66 vs. 80% (p = 0.026), respectively]. In the multivariate analysis, perforation was a significant risk factor of increased rates of LR and OAR as well as reduced 5-year overall and cancer-specific survival. Incidental perforation in rectal cancer surgery is an important risk factor of poor oncological outcome and should be considered in the discussion concerning postoperative adjuvant treatment as well as the follow-up regime.