Splenomegaly in Colon Cancer During Adjuvant Oxaliplatin-based Chemotherapy.

Introduction Oxaliplatin-based chemotherapy is the standard treatment in stage III colon cancer. Oxaliplatin may cause sinusoidal damage and sinusoidal obstruction syndrome (SOS) in the liver. Clinical reflections of SOS are splenomegaly and thrombocytopenia. This study aimed to investigate the frequency of splenomegaly development in patients receiving oxaliplatin-based chemotherapy and thrombocytopenia incidence rates related to this condition.  Materials and methods Files of 50 patients having received fluorouracil and oxaliplatin (mFOLFOX6) regimen for stage 3 colon cancer between 2015 and 2017 were retrospectively reviewed. Spleen volumes (SV) of the patients were calculated using pre-and post-chemotherapy tomographic examinations. A 50% increase in the SV after chemotherapy (SV ≥1.5 change) was accepted as chemotherapy-associated splenomegaly. The patients were divided into two groups as having or not having splenomegaly after chemotherapy. Complete blood count was evaluated prior to each treatment cycle, and on the third month of treatment, termination was used for thrombocyte values.  Results Splenomegaly was determined in 50% of the patients. Cumulative oxaliplatin dosage was found higher in those who developed splenomegaly (p = 0.003). Chemotherapy dose reduction was higher in patients who did not develop splenomegaly (p = 0.015). Thrombocytopenia was confirmed higher in patients who developed splenomegaly compared to those who did not (p = 0.047). Lower thrombocyte counts were found in the complete blood count of the patients having developed splenomegaly which was performed during and 3 months after chemotherapy when compared to those that did not develop splenomegaly (p-values, respectively, as 0.005, 0.038). Upon multivariate logistic regression analysis, cumulative oxaliplatin dose was the single independent factor related to splenomegaly (OR: 7.55 (1.90-31.61); p = 0.004). Conclusion Thrombocytopenia was confirmed to be higher in colon cancer patients receiving adjuvant mFOLFOX6 and developing splenomegaly during the post-treatment period. Moreover, splenomegaly was shown to be associated with the cumulative oxaliplatin doses received. Thrombocytopenia seen in patients receiving oxaliplatin for colon cancer should be a warning in terms of splenomegaly and SOS development.