Maintenance chemotherapy in advanced NSCLC: a population-based assessment of eligibility

Maintenance chemotherapy has been incorporated into treatment paradigms for advanced NSCLC. Eligibility criteria include stable disease/partial response and PS 0-1 after a first line platinum doublet. In practice, maintenance can be difficult to deliver due to patient factors and preferences. We propose to examine the proportion of patients eligible for maintenance and factors associated with the delivery of subsequent lines of chemotherapy.

The BC Cancer Agency provides care to a population of 4.5 million. A retrospective review was conducted of all referred Stage IIIB/IV patients in 2009 who received first line systemic therapy. Baseline characteristics, PS and response after first line and subsequent systemic therapy details were recorded. Patients were deemed potentially maintenance eligible or not based on clinical trial criteria; however maintenance therapy was not delivered to these patients as it was not yet available.

330 patients were identified; 98 were potentially maintenance eligible. The reason for maintenance ineligibility in n = 232; no upfront doublet (n = 41), PS ≥ 2 (n = 38), progressive disease (PD) (n = 53), PS ≥ 2 and PD (n = 62), PS ≥ 2 and unknown response (n = 35), PD and unknown PS (n = 3). Further chemotherapy (2nd line or beyond) was administered in maintenance eligible 68% vs ineligible 56%. Reasons for no further chemotherapy were predominantly decline in PS and brain metastasis. Median OS: 7 m for 1st line only versus 16.8m for ≥ 2 nd line (p < 0.001).

In our population based study, 30% of advanced NSCLC patients were eligible to receive maintenance chemotherapy based on the clinical trial criteria. Despite a good initial PS and disease control only 68% of maintenance eligible patients received subsequent therapy. A clear survival benefit was seen with ≥ 2 nd line treatment. Maintenance therapy or initiation of early second line therapy should be considered for advanced NSCLC patients to improve survival outcomes.