437P - Activity of S-1 for non-small cell lung cancer pretreated with pemetrexed

Date 20 December 2015
Event ESMO Asia 2015 Congress
Session Poster presentation 2
Topics Anti-Cancer Agents & Biologic Therapy
Non-Small-Cell Lung Cancer, Metastatic
Presenter Yoshiro Nakahara
Citation Annals of Oncology (2015) 26 (suppl_9): 125-147. 10.1093/annonc/mdv532
Authors Y. Nakahara1, Y. Takagi2, M. Nagamata2, K. Watanabe2, S. Takahashi2, M. Yomota2, Y. Okuma2, Y. Hosomi2, T. Okamura2, N. Masuda1
  • 1Department Of Respiratory Medicine, Kitasato University School of Medicine,, 252-0374 - Sagamihara/JP
  • 2Department Of Thoracic Oncology And Respiratory Medicine, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, 113-8677 - Tokyo/JP

Abstract

Aim/Background

The 5-fluorouracil derivative S-1 and pemetrexed (PEM) are antimetabolites that mainly target thymidylate synthase. S-1 received approval for treating non-small cell lung cancer (NSCLC) in Japan in December 2004, and has primarily been administered alone for salvage chemotherapy. To our knowledge, whether PEM resistance influences clinical S-1 activity is unavailable.

Methods

Patients with pretreated NSCLC who later underwent S-1 monotherapy were identified from an institutional database. Progression-free survival (PFS) and overall survival (OS) rates after S-1 administration were compared with respect to histological findings using the Kaplan-Meier method and log-rank tests. The PFS and OS rates of patients pretreated with PEM (PEM+) or without (PEM-) for non-squamous NSCLC (n-sq NSCLC) were also compared. The effects of clinical factors on PFS and OS were evaluated using univariate and multivariate analyses with Cox proportional-hazards models.

Results

Among 12 patients (median age, 69 y; range, 39–86 y; female, 33%) who underwent S-1 monotherapy after pretreatment for NSCLC, 65 received PEM-based chemotherapy before S-1 administration. The histological subtypes were adenocarcinoma (65%), squamous cell carcinoma (SCC; 27%) and NSCLC not otherwise specified (8%). Among the patients, 25%, 40%, 25% and 10% had undergone one, two, three and four or more prior chemotherapy regimens, respectively. The median PFS was significantly better for patients with SCC than with n-sq NSCLC (3.4 vs. 2.1 months; HR, 0.62; 95% CI, 0.42–0.90; p = 0.01). Multivariate analysis selected only histology as a statistically significant predictor of a longer PFS. However, median OS did not significantly differ (SCC 8.4 vs. n-sq NSCLC 5.9 months; HR, 0.97; 95% CI, 0.65–1.40; p = 0.86). The PFS were similar between the PEM+ and PEM- groups among the 111 patients with n-sq NSCLC (median 2.1 vs. 2.0 months; HR, 1.17; 95% CI, 0.79–1.74; p = 0.44). The median OS for the PEM+ and PEM- groups were 6.8 and 4.9 months, respectively, not significantly different (HR, 0.70; 95% CI, 0.47–1.06; p = 0.08).

Conclusions

S-1 monotherapy was more effective for SCC than n-sq NSCLC, and prior PEM therapy did not affect S-1 activity in patients with n-sq NSCLC. Further study is warranted.

Clinical trial identification

Disclosure

All authors have declared no conflicts of interest.