OBJECTIVE

To explore the efficiency and adverse effects of the effective EP (etoposide + cisplatin) therapy and its subsequent maintenance therapy with different durations in patients with small cell lung cancer (SCLC).

METHODS

Clinical data of 104 SCLC patients diagnosed and treated at the Jilin Province Cancer Hospital between September 2010 and December 2013 were retrospectively analyzed.Among them, 35 patients were subsequently treated with a 4-week maintenance therapy following the original therapeutic regimen after the effective EP therapy (4-week maintenance therapy group), 35 patients were treated with a subsequent 6-week maintenance therapy (6-week maintenance therapy group), and 34 patients were treated without maintenance therapy (control group).52 patients were in limited stage, and 52 patients were in extensive stage. The progression-free survival (PFS), overall survival (OS) and adverse effects in the 4-week maintenance therapy group, 6-week maintenance therapy group and control group were analyzed.

RESULTS

The median PFS in the control group, 4-week maintenance therapy group and 6-week maintenance therapy group was 4.0, 3.5, and 4.0 months, respectively, and the median OS was 9.0, 10.0 and 12.0 months, respectively, showing no significant difference among the groups (P>0.05 for all). The median PFS was prolonged by 2 months as compared with the control group after the 4-week maintenance therapy in the patients with complete remission in first-line chemotherapy (P=0.041), while the median OS was not improved (P=0.131). Neither the median PFS nor median OS showed statistically significant difference between each two groups in the patients with partial remission in first-line chemotherapy (P>0.05 for all). In the limited stage, the median PFS in the control group, 4-week maintenance therapy group, and 6-week maintenance therapy group was 5.0, 6.5, and 4.0 months, respectively, and median OS was 11.0, 13.5, and 13.0 months, respectively, the differences showed no statistical significance (P>0.05 for all). In the extensive stage, the median PFS in the control group, 4-week maintenance therapy group, and 6-week maintenance therapy group was 3.0, 3.0, and 3.5 months, respectively, showing significant differences (P=0.015); the median OS was 6.5, 8.0, and 8.0 months, respectively, presenting no statistically significant differences (P=0.096). In addition, the PFS in the 6-week maintenance therapy group was significantly improved as compared with that in the control group (P=0.016). Compared with the control group, the incidence rates of nausea (grade 3-4), vomiting, hypodynamia, leukopenia, neutropenia, and thrombocytopenia in the 4-week maintenance therapy group and 6-week maintenance therapy group were increased significantly (P<0.05 for all), however, the side effects were tolerable.

CONCLUSIONS

Prolonging the treatment cycle of EP therapy can improve the PFS in SCLC patients in first-line CR chemotherapy and extensive stage.