Aneuploidy and elevated CEA indicate an increased risk for metachronous metastasis in colorectal cancer.

Purpose: Presently, no markers exist to predict metachronous metastasis at the time a primary colorectal cancer is diagnosed. While aneuploidy indicates poor survival prognosis and elevated carcinoembryonic antigen (CEA) levels the presence of recurrent disease, the predictive value of both markers regarding imminent metachronous metastases is unclear.
Methods: Sixty patients with distant recurrence throughout a 5-year follow-up (TM+) were randomly chosen and 60 patients without metastasis matched to this cohort (TM-). In addition, an enlarged collective (n = 217; n TM+ = 85, n TM- = 132) with median follow-up of 79.2 months was assessed by logistic regression regarding metachronous metastases. Univariate and stepwise regression analyses included clinicopathological characteristics, preoperative CEA levels and aneuploidy assessed by DNA image cytometry.
Results: The matched-pair collective showed aneuploidy in 71.1 % (TM-) and 85.0 % (TM+; p = 0.076), and elevated CEA in 24.5 % (TM-) and 52.2 % [TM+; odds ratio (OR), 3.414; p = 0.007]. The enlarged collective presented aneuploidy in 71.2 % (TM-) and 83.5 % (TM+; OR 2.050, p = 0.038), and elevated CEA in 28.6 % (TM-) and 48.9 % (TM+; OR 2.391, p = 0.020). Elevated CEA and aneuploidy did not show any association (p = 0.919). In contrast, logistic regression analyses demonstrated that besides increased T category (OR 1.745, p = 0.019), both elevated CEA level (OR 2.633, p = 0.015) and aneuploidy (OR 1.929, p = 0.058) were independent predictive markers for metachronous metastasis.
Conclusions: Our data show that aneuploidy and elevated CEA levels besides increased T category could serve for individual risk assessment to predict metachronous metastases. The fact that still aneuploidy missed the significance level by a small margin emphasizes the need for larger validation studies.