Strategies for prolonged therapy in patients with advanced non-small-cell lung cancer

A key challenge in the treatment of advanced non-small-cell lung cancer (NSCLC) is improving outcomes for patients who have achieved at least stable disease after standard first-line therapy. Although current guidelines recommend a maximum of six cycles of first-line therapy, even in responding patients, recent trials have shown benefit with maintenance therapy.

We reviewed the English literature for randomized controlled trials on prolonged therapy for NSCLC conducted between January 1999 and January 2010. The search was supplemented by a review of abstracts presented at the American Society of Clinical Oncology annual meetings (2004 to 2010), the World Lung Cancer Conference (2007 to 2009), and the 2009 Joint European CanCer Organisation-European Society for Medical Oncology conference.

Several alternative strategies for prolongation of chemotherapy have been tested: these can be broadly categorized as continuation (prolongation of the first-line regimen until disease progression, unacceptable toxicity, or administration of a predefined greater number of treatment cycles), switch-maintenance (administration of an active agent immediately after completion of the initial course of chemotherapy), and continuation-maintenance (ongoing administration of a lower intensity version of the first-line chemotherapy regimen). These approaches differ from traditional second line, which is defined as treatment administered after documented clinical progression subsequent to first-line therapy.

There are no data to support continuation chemotherapy in advanced NSCLC. Switch-maintenance trials with erlotinib and pemetrexed have demonstrated an improvement in overall survival. Thus far, continuation-maintenance has shown an improvement in progression-free survival, without an overall survival advantage.