Correlates and outcomes of tumor adherence in resected colonic and rectal cancers

The aims of this study were to examine the associations between tumor adherence and other operative findings, postoperative complications, recurrence, and survival after resection of colorectal cancer. The prognostic importance of tumor adherence to other organs or structures, either by direct invasion (T4) or simply by inflammatory adhesions, is yet to be clearly defined as earlier studies have been limited in size or have not used contemporary multivariable statistical techniques. Data were drawn from a comprehensive, prospective hospital registry of all resections for colorectal cancer between January 1971 and December 2000 with follow-up to December 2005. Statistical analysis employed the X² test, Kaplan-Meier estimation, and proportional hazards regression with a significance level of <0.05 and 95% confidence intervals (CI). Tumor adherence was identified in 268 of 2504 resections (10.7%). Adherent tumors were more likely than nonadherent tumors to be spontaneously or surgically perforated or transected, to have nodal metastases and to be poorly differentiated. Venous invasion was more frequent in adherent colonic but not rectal tumors. Adherence was associated with only 5 of 16 medical and surgical complications considered. In rectal cancer, adherence was independently associated with pelvic recurrence (hazard ratio 1.8, 95% CI 1.2–2.7) and diminished survival (hazard ratio 1.6, 95% CI 1.3–2.0) after adjustment for other variables. In rectal cancer, tumor adherence indicates a poor prognosis after adjustment for other prognostic factors, regardless of whether actual tumor invasion of the adherent structure has occurred. However, adherence is not associated with survival after resection of colonic cancer.