A phase II study of a combination treatment of alternate-day S-1 and lentinan as first-line chemotherapy for unresectable or recurrent gastric cancer

Authors: S. Yoshino, T. Nishimura, K. Sakata, S. Yoshida, T. Furuya, T. Yamamoto, T. Kawaoka, R. Shimizu, T. Sato, K. Matoba, H. Morioka, M. Iida, N. Suzuki, S. Takeda, T. Ueno, S. Hazama, H. Nagano

Journal: Annals of Oncology

Study Design: Phase II, multi-institutional, prospective study

Participants: 37 patients with unresectable or recurrent gastric cancer

Intervention: The patients received S-1 on an alternate-day schedule (Monday, Wednesday, Friday, and Sunday) at the recommended dosage of 40 mg/m2 twice daily, along with weekly intravenous administration of lentinan (2 mg/body). The treatment continued until disease progression or the occurrence of intolerable adverse events.

Outcome Measures:

• Primary endpoint: Time to treatment failure (TTF)
• Secondary endpoints: Overall survival (OS), progression-free survival (PFS), response rate (RR), and occurrence rate of adverse events.

Summary: The study aimed to evaluate the efficacy and safety of an alternate-day S-1 regimen combined with lentinan in patients with unresectable or recurrent gastric cancer. The results showed a median TTF of 5.3 months and a median OS of 12.1 months. The disease control rate (PR + SD) was 75.9%. The treatment was well-tolerated, with relatively mild adverse events, even in elderly patients. The most common adverse event was neutropenia, and non-hematologic adverse events were rare. The study concluded that the combination of alternate-day S-1 and lentinan is a well-tolerated and effective treatment option for unresectable or recurrent gastric cancer, particularly in elderly patients.