Phase II study of S-1 in patients with previously-treated invasive thymoma and thymic carcinoma: North Japan lung cancer study group trial 1203

Yoko Tsukita, Akira Inoue, Shunichi Sugawara, Shoichi Kuyama, Taku Nakagawa, Daijiro Harada, Hisashi Tanaka, Kana Watanabe, Yoshiaki Mori, Toshiyuki Harada, Toshihiko Hino, Masanori Fujii, Masakazu Ichinose

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Objectives: Invasive thymoma (IT) and thymic carcinoma (TC) are rare epithelial neoplasms arising in the anterior mediastinum. Platinum-based chemotherapies are widely used for first-line treatment of unresectable IT and TC, but no standard treatment has been established for previously-treated IT and TC thus far. Because promising efficacy of S-1 (tegafur, gimeracil and oteracil combination) has been reported in some retrospective studies, we conducted the first prospective phase II trial to evaluate its efficacy in previously-treated patients with advanced IT and TC. Materials and Methods: Patients progressing after at least one regimen of systemic chemotherapy received S-1 orally at a dose based on body surface area for 2 weeks followed by one week of rest until tumor progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR) and secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity profile. We defined an ORR of 25% as indicating potential usefulness while ORR of 10% was the lower limit of interest. Results: Forty patients were enrolled (IT, n = 20; TC, n = 20). ORR was 17.5% (95% CI 7.3–32.8; IT, 10%; TC, 25%), disease control rate was 85% (IT, 95%; TC, 75%). Median PFS was 7.0 months (IT, 11.3 months; TC, 5.4 months), and median OS was 40.3 months (IT, 58.5 months; TC, 22.7 months) with a median follow-up of 51.9 months. Major toxicities (grade 3–4) were anorexia (10%), neutropenia (7.5%) and pneumonitis (5%). No treatment-related death was observed. Conclusion: Although the primary endpoint was not met, S-1 monotherapy did have effects similar to recently reported immunotherapies for TC but at much lower cost. S-1 could represent a treatment option for previously-treated advanced TC. This trial was registered as UMIN 000008174.

Original languageEnglish
Pages (from-to)89-93
Number of pages5
JournalLung Cancer
Publication statusPublished - Jan 2020
Externally publishedYes


  • Phase II
  • Prospective
  • S-1
  • Thymic carcinoma
  • Thymoma

ASJC Scopus subject areas

  • Oncology
  • Pulmonary and Respiratory Medicine
  • Cancer Research


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