Possible surrogate marker for an effective dose-dense chemotherapy in treating ovarian cancer

Objective: To dissect the correlated hematologic markers that reflect the clinical outcome or treatment response in patients receiving dose-dense chemotherapy with a combination of platinum (cisplatin or carboplatin) and paclitaxel. Materials and Methods: From 2009 to 2014, we enrolled 55 ovarian cancer patients (total 67 courses) including first-line, persistent, platinum-sensitive, or platinum-resistant disease in MacKay Memorial Hospital, Taipei, Taiwan. Weekly pretreatment complete blood counts and calculated ratios [platelet/neutrophil ratio, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), neutrophil/monocyte ratio, platelet/monocyte ratio, lymphocyte/monocyte ratio] during dose-dense chemotherapy were collected. By grouping these hematologic biomarkers into three different response subgroups (responsive, stable, and nonresponsive) according to CA125 trend, the data were analyzed using one-way analysis of variance, and using post hoc-Tukey test for comparing each other. A p value < 0.05 was considered to be statistically significant. Results: Absolute counts of lymphocytes and platelets, PLR, platelet/neutrophil ratio, platelet/monocyte ratio (all p < 0.001), and NLR (p=0.013) had statistically significant differences. Moreover, using box-and-whisker plot, absolute count of lymphocyte, PLR, and NLR showed most remarkable discrepancy in responsive, stable, and nonresponsive patients. Subgroup analysis for primary, platinum-sensitive, and platinum-resistant patients further revealed that PLR and NLR were significantly correlated to the outcome of dose-dense chemotherapy. Conclusion: Lower PLR or lower NLR had better treatment response for dose-dense chemotherapy and are possible markers for representing treatment response in dose-dense chemotherapy. For a clinician, this is useful for timing when to switch to another chemotherapy regimen.