Oxaliplatin-induced increase in splenic volume: experiences from multicenter study in Japan

Chemotherapy with oxaliplatin is known to induce sinusoidal obstruction syndrome (SOS). In a previous single-center study, we reported that oxaliplatin-induced increase in splenic volume (SV) is strongly indicative of SOS, and that this increase in SV persisted for > 1 year after completing chemotherapy. The aim of this study was to confirm the oxaliplatin-induced SV change in a multicenter study in patients with stage III colon cancer in Japan.

We enrolled 59 patients who underwent curative resection for stage III colon cancer in the FACOS study in a phase II multi-center clinical study. Participants received mFOLFOX6 or CAPOX as adjuvant chemotherapy. SV change was assessed three times by computed tomographic volumetry: before surgery, on completion of adjuvant chemotherapy, and 1 year after completing adjuvant chemotherapy.

SV on completing and 1 year after chemotherapy was significantly higher than that before surgery (P < 0.001). Oxaliplatin-induced SOS persisted for > 1 year after the completion of adjuvant chemotherapy in half of the patients. There was no difference in 3-year disease-free survival with respect to the presence or absence of increased SV. An increase in SV was observed in 72% of patients treated with mFOLFOX6 and 94% of patients treated with CAPOX (P = 0.13).

This study can be verified the findings observed in our previous single-center study, oxaliplatin-based adjuvant chemotherapy was associated with an increase in SV. Furthermore, this increase can persist for > 1 year. The continuous presence of SOS may have a negative impact on prognosis in patients that develop recurrent disease.