The impact of spontaneous tumour perforation on outcome following colon cancer surgery.

OBJECTIVE: The impact of spontaneous tumour perforation on survival following surgery for colon cancer is unclear. This study compares survival outcomes for patients with perforated colonic cancer with stage-matched nonperforated cancer.

METHOD: A prospective histological database was searched for all patients undergoing resection for adenocarcinoma of the colon between 1996 and 2002. Patients with T4 cancer were selected and classified into those with spontaneous perforation at the tumour site and those with nonperforated tumour. Patients with synchronous colonic and rectal cancers, familial polyposis, inflammatory bowel disease, iatrogenic or remote colonic perforation were excluded. Histological variables were combined with clinical data obtained by case note review. Data were analysed for differences in demographics, histological variables, operative mortality, disease-free and overall survival. Multivariate analysis of factors predictive of overall survival in both groups was performed.

RESULTS: Of 960 patients identified, 52 patients had spontaneous tumour perforation and 82 patients served as the T-stage matched control group. Overall survival at 2 years was 47% and 54% and at 5 years was 28% and 33% for perforated and nonperforated cancers respectively. Patients with perforated cancers were more likely to present with metastatic disease and undergo emergency surgery with a higher 30-day mortality. There was a trend towards reduced overall survival in the perforated group (P = 0.06), but no difference in disease-free survival (P = 0.43). On multivariate testing, 'emergency surgery' and 'age >75 years' were the only independent predictors of mortality in the perforated and nonperforated group respectively.

CONCLUSION: Both perforated and nonperforated T4 colon cancers have a poor prognosis. Spontaneous perforation of the cancer is associated with reduced overall survival, due to higher 30-day mortality, but in itself does not appear to significantly impact on disease-free survival. Rather, it is the advanced oncological stage at which perforated cancers present that determines outcome.