The benefits of PSK to lung cancer patients have been recently demonstrated in more advanced stage III disease where radiotherapy is only marginally effective.
In a non-randomised controlled study of stage I/III non-small cell lung carcinoma, patients who responded well to radiotherapy were given PSK (3g/day) for two weeks followed by 2 weeks rest or placebo in 2-week repeated cycles55.
The patients (n=62) being given PSK experienced a significant overall improvement in 2-year (58% vs 22%; p<0.0001) and 5-year (27% vs 7%; p< 0.0001) survival rates compared to the placebo group (n=123). When stratified to disease stage and age, patients with stage I/II (n=22) and stage III (n=32) epidermoid carcinoma receiving PSK experienced significantly better survival rate (39% vs 16%; p<0.005 and 22% vs 5%; p<0.004) than in the placebo groups receiving radiotherapy alone (n=42 and n=46, respectively). Furthermore, patients greater than 70 years old who received PSK had better 2- year and 5-year survival rates than those not receiving PSK (p<007).