Objective: To investigate the expression of thymidylate synthase (TS) in patients with advanced lung adenocarcinoma and its relation with the therapeutic effect of pemetrexed.
Methods: The clinicopathological data of 38 patients with stage IIIIB/IV lung adenocarcinoma receiving pemetrexed treatment were retrospectively analyzed. The tumor samples of the patients were collected for detecting TS expression using RT-PCR, and the therapeutic effect of the treatment was analyzed.
Results: TS positivity was found in 26.32 (10/38) of the patients. TS positivity was not correlated to gender, TNM stage or PS score. The total response rate of pemetrexed treatment (CR+PR) was 34.21 (13/38) in these patients, and the rate was 39.29% (11/28) in TS-negative patients, as compared to 20.00% (2/10) in the positive patients (P=0.087). Patients with low TS expression had significantly higher control rate by pemetrexed treatment than those with TS overexpression [89.29% (25/28) vs 40.00% (4/10), P=0.002].
Conclusion: TS expression may serve as a potential indicator of chemosensitivity to pemetrexed in patients with advanced lung adenocarcinoma.