[Two cases of long-term survival of metastatic colorectal cancer following treatment with polysaccharide K and mFOLFOX6 therapy].

Protein-bound polysaccharide K (PSK) has been used as a chemoimmunotherapy agent for the treatment of colorectal cancer. Recently, PSK was reported to be able to decrease some adverse effects of FOLFOX therapy, including neutropenia and peripheral neurotoxicity. Here, we report 2 patients with metastatic colorectal cancer, who unexpectedly were able to receive many courses of PSK+mFOLFOX6 therapy for a prolonged period. We speculate that FOLFOX therapy may achieve long-term tumor control with the aid of PSK without serious side effects for metastatic colorectal cancer patients.