Hendriks, Tessa E.

3576 Background: Identification of a marker with strong prognostic impact on clinical outcomes would aid in the management of pts with primary, curatively resected CRC. We conducted a pooled individual pt data analysis to confirm the prognostic value of pTIMP-1 for overall survival (OS) in stage II and III CRC. Methods: pTIMP-1 was determined in plasma using immunoassays. Samples and clinical data were included from 5 studies with a total of 1,042 stage II/III pts resected between 1991 – 2006 (Holten-Andersen (HA), 2000 [n=378], HA, 2004 [n=226], Waas, 2005 [52], Birgisson, 2010 [225], Nielsen, 2011[n=161]). To provide comparable measures across studies, pTIMP-1 values were rescaled using fractional ranks (FR, based on ranks and sample size). Pts were grouped by the median of the pTIMP-1 FR score. Stratified log-rank tests and multivariate Cox models assessed the association between OS and pTIMP-1 FR. Results: Overall, 59% were male; median age 69 years; 56% had stage II disease and 50% had colon cancer. The median follow-up was 5.5 years with 457 deaths. Continuous pTIMP-1 FR as a linear effect was significantly associated with OS (p < .0001, HR=1.38 for a 0.3 unit increase in FR score, 95% CI 1.25 to 1.52).Pts with pTIMP-1 FR above vs below the median had significantly shorter OS (HR, 1.72; 95% confidence interval[CI], 1.42 to 2.08, p <0.0001), which remained significant after adjusting for age, gender, stage, disease location, and serological CEA (HR, 1.31; 95%CI, 1.07 to 1.60; p = 0.009). Results by stage are shown in the table. No evidence of an interaction between pTIMP-1 and stage or disease location (colon vs. rectal) was observed (all p > 0.6). Conclusions: pTIMP-1 is a strong prognostic marker for predicting OS independent of age, gender, CEA, stage and site of disease in curatively resected stage II and III CRC. [Table: see text]