Chemotherapy beyond 3^rd line in NSCLC – A retrospective analysis

Abstract

Background: Palliative chemotherapy is standard of treatment of stage IV NSCLC. Although there is evidence for the effectiveness of the first 3 lines of therapy, little is known about the response to further therapy beyond the 3^rd line. Our aim is to analyze response rates after 4^th, 5^th or 6^th line chemotherapy in stage IV NSCLC.

Methods: A retrospective analysis of stage IV NSCLC patients who received firstline therapy in our institution from 2008 to 2013 was performed. Patients who had at least one cycle of 4^thline treatment were selected for further evaluation. We analyzed therapy regime and best response (according to RECIST 1.1).

Results: Overall, we identified 1174 Pat with first-line therapy during the period. Of these, 40% (469 Patients) received a 2^nd line therapy and 17% (199) 3^rd line therapy.Thereafter, 4^th line therapy was performed in 6.2% (n=73), 5^th line in 1.8%. (21) and 0.4% (5) had a 6^th line of therapy, respectively. Objective response rates (PR, CR) were: in 4^th line 1.4% (1/73), in 5^th line 14.3% (3/21) and in 6^th line 0% (0/5), respectively. The proportion of patients with stable disease (SD) was: 4^th line 37% (27/73), 5^th line 33% (7/21) and 6^th line 60% (3/5).

The median time between diagnosis of lung cancer and initiation of fourth line treatment was 495 days (165-1887 days).

In 42 patients with 4 four or more lines of therapy, who were eligible for molecular testing, we detected 4 cases of EGFR mutation and one EML-ALK fusion.

Conclusion: The effective response to systemic therapy beyond 3^rd line seems to be limited but short term stabilization was seen in a proportion of patients. Because of unclear benefits, further lines of therapy should be limited to selected groups of patients.