Effect of PSK on FOLFOX4-induced peripheral neuropathy and bone marrow suppression in patients with metastatic colorectal cancer.

Abstract

596 Background: FOLFOX4 has been confirmed as an effective treatment for metastatic colorectal cancer and is used as a postoperative adjuvant therapy. However adverse effects such as cold-sensitive paresthesia and bone marrow suppression are common and may necessitate changes in chemotherapy regimen despite FOLFOX effectiveness. PSK, a polysaccharide derived from a species of mushroom, has been developed in Japan as an immune-enhancing agent and is widely used in patients with gastric, colorectal and pulmonary cancer. PSK has also been reported to decrease some adverse effects of chemotherapy. Methods: FOLFOX4 combined with PSK was administered to patients with metastatic colorectal cancer and the results were evaluated. Eight cycles of FOLFOX4 and PSK (3.0 g/day, p.o.) were given to 25 patients with metastatic colorectal cancer (19 hepatic, 3 pulmonary and 3 peritoneal). Results: No patients showed CR (complete response, 0%) while PR (partial response), SD (stable disease) and PD (progressive disease) were seen in 48%, 36% and 16% of patients, respectively. Response rate was 48% and disease control rate was 84%. Frequency of adverse effects was significantly lower than described in the published data. Grades 1 and 3 neutropenia occurred in 48% and 24% of patients, respectively; grades 1 and 3 nausea in 48% and 4%, respectively; and grades 1, 2 and 3 sensory neurotoxicity in 52%, 4% and 0%, respectively. No patient dropped out due to adverse effects in this study. Conclusions: PSK plus FOLFOX4 seems as effective as FOLFOX4 monotherapy, and significantly less toxic. These results suggest that this combination therapy may be more effective when given for a longer period, with lower incidence of adverse effects. No significant financial relationships to disclose.