497 Background: Although a demonstrated clinical efficacy, a non negligible proportion of colorectal cancer patients does not seem to benefit from regorafenib and are consequently exposed to unnecessary toxicity. LDH serum levels represent an indirect marker of tumour hypoxia, neo-angiogenesis and worse prognosis in many tumour types. In colorectal cancer LDH showed a correlation with treatment outcome for patients receiving antiangiogenetic treatment, thus suggesting a possible interaction with the activity profile of these drugs. We analyzed the role of LDH serum levels in predicting clinical outcome for pre-treated metastatic colorectal cancer patients receiving regorafenib. The final aim was to individuate a potentially reliable and easy to use marker for patients stratification. Methods: 118 colorectal cancer patients treated with regorafenib were available for our analysis. For all patients, LDH values were collected within one month before the procedure and after treatment end. LDH cutoff value was determined by ROC curve analysis, patients were then divided into two groups (A and B, below and above cut-off level respectively). Patients were also classified according to the variation in LDH serum levels pre- and post-treatment (increased patients vs. decreased patients). Results: Patients in group A and B proved homogeneous for all clinical characteristics analyzed. In group A patients median progression free survival (PFS) was 3.18 months, whereas it was 1.87 months in group B patients (p = 0.0018). Median overall survival (OS) was 6.23 months and 3.28 months in group A and B respectively (p = 0.048). Significant differences were not noted among the 2 groups for response rate. All the other clinical variables analyzed failed to show any correlation with patients outcome. Conclusions: Our observations seem to suggest a role of LDH as a marker of clinical outcome in colorectal cancer patients receiving regorafenib. We can then speculate that high LDH patients may not be optimal candidates for regorafenib. After further confirmation in larger trial, these findings may be relevant for a better patients stratification and selection.
The Role of HER‐3 Expression in the Prediction of Clinical Outcome for Advanced Colorectal Cancer Patients Receiving Irinotecan and Cetuximab