The DCC protein and prognosis in colorectal cancer.
BACKGROUND  Allelic loss of chromosome 18q predicts a poor outcome in patients with stage II colorectal cancer . Although the specific gene inactivated by this allelic loss has not been elucidated , the DCC ( deleted in colorectal cancer ) gene is a candidate . We investigated whether the expression of the DCC protein in tumor cells is a prognostic marker in colorectal carcinoma . METHODS  The expression of DCC was evaluated immunohistochemically in 132 paraffin-embedded samples from patients with curatively resected stage II and III colorectal carcinomas . The Cox proportional-hazards model was used to adjust for covariates including age , sex , tumor site , degree of tumor differentiation , and use of adjuvant therapy . RESULTS  The expression of DCC was a strong positive predictive factor for survival in both stage II and stage III colorectal carcinomas . In patients with stage II disease whose tumors expressed DCC , the five-year survival rate was 94 . 3 percent , whereas in patients with DCC-negative tumors , the survival rate was 61 . 6 percent ( P < 0 . 001 ) . In patients with stage III disease , the respective survival rates were 59 . 3 percent and 33 . 2 percent ( P = 0 . 03 ) . CONCLUSIONS  DCC is a prognostic marker in patients with stage II or stage III colorectal cancer . In stage II colorectal carcinomas , the absence of DCC identifies a subgroup of patients with lesions that behave like stage III cancers . These findings may thus have therapeutic implications in this group of patients
