Background: Despite all efforts in extending the resectability rates of colorectal liver metastases, thus improving the prognosis of the patients, tumor recurrence occurs in many patients. Occult dissemination of tumor cells might reflect a minimal residual disease that is not eliminated by primary surgery. Because the prognostic effect of disseminated tumor cells (DTC) is still uncertain in this clinical setting, we analyzed these cells in the peripheral blood and bone marrow of patients undergoing hepatic resection of colorectal liver metastases.
Methods: In 108 patients with colorectal liver metastases, the presence of DTC in the peripheral blood and bone marrow was detected with CK20 RT-PCR. Clinical data were prospectively collected, and multiple variables were analyzed regarding their influence on overall survival.
Results: DTC in the peripheral blood were detected in 40% of the patients. In 25% of the patients, DTC were detected in the bone marrow. The median follow-up was 34 months. Fifty-nine of 108 patients died from tumor relapse. Multivariate analysis determined detection of DTC in the bone marrow to be an independent prognostic factors for overall survival (P = 0.038).
Conclusions: This large series of patients with hepatic resection of colorectal liver metastases demonstrated that detection of CK20-positive DTC via RT-PCR in the bone marrow compartment negatively influences overall survival. The evidence of DTC in the bone marrow might serve as an additional individual marker to select patients for adjuvant treatment after liver metastases resection.