Annals of Thoracic Medicine (Jan 2015)

Progression-free survival, post-progression survival, and tumor response as surrogate markers for overall survival in patients with extensive small cell lung cancer

  • Hisao Imai,
  • Keita Mori,
  • Kazushige Wakuda,
  • Akira Ono,
  • Hiroaki Akamatsu,
  • Takehito Shukuya,
  • Tetsuhiko Taira,
  • Hirotsugu Kenmotsu,
  • Tateaki Naito,
  • Kyoichi Kaira,
  • Haruyasu Murakami,
  • Masahiro Endo,
  • Takashi Nakajima,
  • Nobuyuki Yamamoto,
  • Toshiaki Takahashi

DOI
https://doi.org/10.4103/1817-1737.146885
Journal volume & issue
Vol. 10, no. 1
pp. 61 – 66

Abstract

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Objectives: The effects of first-line chemotherapy on overall survival (OS) might be confounded by subsequent therapies in patients with small cell lung cancer (SCLC). We examined whether progression-free survival (PFS), post-progression survival (PPS), and tumor response could be valid surrogate endpoints for OS after first-line chemotherapies for patients with extensive SCLC using individual-level data. Methods: Between September 2002 and November 2012, we analyzed 49 cases of patients with extensive SCLC who were treated with cisplatin and irinotecan as first-line chemotherapy. The relationships of PFS, PPS, and tumor response with OS were analyzed at the individual level. Results: Spearman rank correlation analysis and linear regression analysis showed that PPS was strongly correlated with OS (r = 0.97, p < 0.05, R 2 = 0.94), PFS was moderately correlated with OS (r = 0.58, p < 0.05, R 2 = 0.24), and tumor shrinkage was weakly correlated with OS (r = 0.37, p < 0.05, R 2 = 0.13). The best response to second-line treatment, and the number of regimens employed after progression beyond first-line chemotherapy were both significantly associated with PPS ( p ≤ 0.05). Conclusion: PPS is a potential surrogate for OS in patients with extensive SCLC. Our findings also suggest that subsequent treatment after disease progression following first-line chemotherapy may greatly influence OS.

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