Serum iron levels as new predictive factor in FOLFOX/FOLFIRI with or without molecularly targeted drug therapy.

Abstract

e14004 Background: An increase in serum iron levels after administration of various anticancer drugs was reported (Follezou et al, NEOPLASMA 1985). We have also reported an increase in serum iron levels during FOLFOX and FOLFIRI therapies (ASCO 2009: #e15110) and a correlation between prognosis and transition of serum iron levels in advanced colorectal cancer (CRC) patients (ASCO 2011: #e14141). The aim of this cohort study was to evaluate the correlation between prognosis and serum iron levels in advanced CRC patients treated with FOLFOX/FOLFIRI ± molecularly targeted drugs. Methods: Serum iron levels were measured before and at 48 hr after treatment (FOLFOX/FOLFIRI ± molecularly targeted drugs) in 69 advanced CRC patients, all of whom died between December 2005 and December 2011. No patients were treated with radiotherapy. Taking the median rate of increase in serum iron levels as the cut-off value in each therapy, the patients were categorized into cohort I (increase rate over cut-off value in at least one therapy) and cohort II (increase rate under the cut-off value in all therapies). Prognosis was evaluated between the two cohorts using the Kaplan-Meier method and the log rank test. Results: No significant bias in patient characteristics was observed between the two cohorts. Serum iron levels transiently increased after treatment (p<0.001), then returning to baseline within 2 weeks. Median survival time (MST) in cohort I (n: 41) and cohort II (n: 28) was 430 and 377 days, respectively. The MST was significantly better in cohort I (p=0.0496). No significant differences were observed in the frequency of chemotherapies or number of patients treated with molecularly targeted drugs between the two cohorts. Conclusions: Cohort I showed a statistically significant better prognosis. The results suggest that serum iron levels could be used as a new predictive factor in FOLFOX/FOLFIRI ± molecularly targeted drug therapy. In Cohort II patients, molecularly targeted drugs should be used positively for further improvement in prognosis.