Background and aims: Accurate, long-term risk predictors for colorectal cancer development in patients with sporadic adenomas are lacking. We sought to validate biomarkers predictive of metachronous colorectal cancer (mCRC) in patients with sporadic colorectal adenomas, using 374 consecutive patients from a large defined population.
Materials and methods: Risk evaluation was performed for patient and adenoma risk factors (morphometric longest nuclear axis and immunohistochemical markers survivin, human telomerase reverse transcriptase (hTERT), beta-catenin, p16INK4a, p21CIP1, and cyclin D1). Diagnostic accuracy was assessed by receiver-operating characteristics curve analysis, and uni- and multivariate survival analysis was performed.
Results/findings: Of the 374 patients, 26 (7%) developed mCRC with a median of 5.6 years (range 2-19) from index adenoma. Independent risk factors included age greater than or equal to 60 years, proximal location, multiplicity (greater than or equal to three adenomas), and high-grade neoplasia, with high-grade intraepithelial neoplasia and proximal location as the strongest on multivariate analysis (hazard ratio [HR] of 4.1 and 5.2, respectively; both p< 0.05). The molecular markers hTERT (HR 11.3, 95% confidence interval [CI] 3.9-33.1; p < 0.001) and survivin (HR 7.0, 95% CI 2.4-20.5; p < 0.001) were independent predictors for mCRC, and proximal location (4 of 16 = 25% with mCRC) was the only clinical one. The value of hTERT and survivin were retained in the validation set. Survivin and hTERT together yielded high mCRC risk when both were positive (15 of 51 = 29%; HR 14.3, 5.6-36.5), modest with one positive (survivin 4 of 90 = 4.4%; hTERT 4 of 60 = 6.7%), and no risk with both negative (0 of 144 = 0%).
Interpretation/conclusion: hTERT and survivin are the best risk predictors for long-term, mCRC development in patients with sporadic colorectal adenomas.