Alternate-day treatment with S-1 in patients with gastric cancer: a retrospective study of strategies for reducing toxicity

• Published in: International journal of clinical oncology Vol. 15; no. 2; pp. 166 - 171
• Main Authors: Sakuma, Kazuya, Hosoya, Yoshinori, Arai, Wataru, Haruta, Hidenori, Ui, Takashi, Kurashina, Kentaro, Saito, Shin, Hirashima, Yuki, Yokoyama, Taku, Zuiki, Toru, Hyodo, Mananobu, Nagai, Hideo, Yasuda, Yoshikazu, Shirasaka, Tetsuhiko
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.04.2010; Springer Nature B.V
• Subjects: Adult; Aged; Antimetabolites, Antineoplastic - administration & dosage; Antimetabolites, Antineoplastic - adverse effects; Cancer; Cancer Research; Chemotherapy; Chemotherapy, Adjuvant; Disease-Free Survival; Drug Administration Schedule; Drug Combinations; Female; Gastrectomy; Humans; Kaplan-Meier Estimate; Lymph Node Excision; Male; Medicine; Medicine & Public Health; Middle Aged; Oncology; Original Article; Oxonic Acid - administration & dosage; Oxonic Acid - adverse effects; Palliative Care; Retrospective Studies; Side effects; Stomach; Stomach Neoplasms - drug therapy; Stomach Neoplasms - mortality; Stomach Neoplasms - surgery; Surgical Oncology; Tegafur - administration & dosage; Tegafur - adverse effects; Time Factors; Toxicity; Treatment Outcome; Alternate-day treatment; TS-1; Adverse events; Gastric cancer; S-1
• ISSN: 1341-9625; 1437-7772
• DOI: 10.1007/s10147-010-0036-y

Background In patients with adverse events of S-1, the dose is generally reduced or the treatment cycle is shortened. Whether the therapeutic effectiveness of modified regimens is similar to that of the standard dosage remains unclear. Methods We retrospectively studied patients with gastric cancer who received S-1 on alternate days. Results A total of 266 patients received S-1 on alternate days. In 116 patients, S-1 was initially given at the standard dosage but was switched to alternate-day treatment because of toxicity within 28 days on average. The other 150 patients initially received alternate-day treatment because of poor general condition. In the adjuvant chemotherapy group ( n  = 96), the 3-year survival rate was 88% in patients with stage II, 73% in stage IIIA, and 67% in stage IIIB who underwent D2 lymph-node dissection. In the palliative surgery group ( n  = 96), the response rate was 13%, with a median survival time (MST) of 624 days. In patients with unresectable/recurrent disease ( n  = 74), the response rate was 25%, with an MST of 338 days. Among the 116 patients who initially received treatment on consecutive days, 100% had grade 1, 53% had grade 2, and 5.2% had grade 3 adverse events. When S-1 was switched to alternate-day treatment, toxicity decreased in all patients. In the 266 patients who received alternate-day treatment, 8% had grade 1, 6% had grade 2, and 0% had grade 3 adverse events. Conclusion Alternate-day treatment with S-1 may have milder adverse events without compromising therapeutic effectiveness.