No correlation between pretreatment serum CEA levels and tumor volume in locally advanced rectal cancer patients

Background: Although serum carcinoembryonic antigen (CEA) levels reflect tumor volume in rectal cancer patients intrapersonally, it is unclear interpersonally. We determined the correlation between pretreatment serum CEA levels and tumor volume.

Methods: A total of 489 patients with locally advanced primary rectal cancer who underwent preoperative chemoradiotherapy followed by surgery between October 2001 and April 2007 were retrospectively evaluated. CEA levels were measured by chemiluminescent microparticle immunoassay, and magnetic resonance (MR) volumetry was performed using MR data. The correlation between CEA levels and tumor volume was assessed using linear regression analysis and one-way analysis of variance. The prognostic values of CEA levels and tumor volume for survival were evaluated.

Results: There was no significant correlation between CEA levels and tumor volume. The five-year overall survival and disease-free survival were 89.0%, 80.6% and 82.9%, and 72.0%, 70.0% and 60.3% in patients with CEA levels of ≤3 ng/ml, >3-10 ng/ml, and >10 ng/ml, respectively. Tumor volume had no prognostic value for either overall survival or disease-free survival

Conclusions: Pretreatment serum CEA levels were not correlated with tumor volume. While there was no correlation between tumor volume and survival, there was a positive correlation between CEA levels and survival.