Background: Colorectal cancer (CRC) harbors accumulated genetic alterations with cancer progression, which results in uncontrollable disease. To regulate the most malignant CRC, we have to know the most dismal phenotype of stage IV disease.
Methods: A retrospective review of the Kitasato University Hospital was performed (from 1990 to 2001) to extract the 162 resected stage IV CRC. Clinical variables were tested for their relationship to survival in a multivariate prognostic analysis and revealed the interaction of the prognostic factors.
Results: In stage IV CRC with noncurable resection, the most robust univariate predictors for poor prognosis were preoperative high value of CA19-9, peritoneal dissemination, depth of invasion, age, extent of liver metastases, pathologic lymph node metastasis status, and gender as tumor factors, and postoperative therapy, perioperative transfusion, and lymph node dissection extent as treatment factors. Among these factors, postoperative therapy (p < 0.0001), perioperative transfusion (0.0002), CA19-9 (0.001), extent of liver metastases (0.004), and peritoneal dissemination (0.02) were identified as independent prognostic factors by multivariate analysis. Interestingly, among the independent prognostic factors, treatment factors did not depend upon tumor factors and the combination of the three tumor factors (CA19-9, extent of liver metastases, and peritoneal dissemination) can clearly classify the patients into the definite prognostic groups.
Conclusion: Our results suggested that the most dismal CRC harbors three definite vectors that may represent the strongest phenotype of putative systemic immune (CA19-9), distant metastasis (extent of liver metastases), and local progression (peritoneal dissemination).