Combined chemo-radiotherapy for locally advanced non-small cell lung cancer: current status and future development.

Currently, combinations of chemotherapy and radiotherapy are the standard treatment approach for locally advanced NSCLC patients. Concomitant chemo-radiotherapy, although associated with increased acute toxicity, has demonstrated to be the better strategy over sequential chemoradiotherapy, and it is to be considered a standard approach in patients with good performance status (0-1). However, the approach to locally advanced NSCLC and to chemo-radiotherapy regimens remains heterogeneous among oncologists, and clinical outcomes are yet disappointing. Thus, the search of new strategies is mandatory. The main fields of research aiming at improving the survival of locally advanced NSCLC patients are: the addition of further combination chemotherapy as induction or consolidation to concurrent chemo-radiotherapy, and the integration of molecularly targeted therapies into conventional chemo-radiotherapy regimens.

Irreversible EGFR inhibitors in the treatment of advanced NSCLC.

The epidermal growth factor receptor (EGFR) is among the most important targets in the treatment of advanced non-small cell lung cancer (NSCLC). Erlotinib and gefitinib, two small molecules, are reversible EGFR tyrosine kinase inhibitors (TKIs). Non-small cell lung cancers with EGFR mutations, are characterized by excellent responses when treated with the EGFR-TKIs gefitinib and erlotinib. However, all the patients with tumors harbouring EGFR mutations experience disease progression after a median of 10 to 14 months of treatment with gefitinib or erlotinib. A group of new generation EGFR-TKIs irreversibly inhibit EGFR-TK and represent one of the strategies that may potentially overcome the acquired resistance to gefitinib and erlotinib or achieve better outcomes than reversible inhibitors in the first-line treatment of EGFR mutant lung cancers. Afatinib (BIBW 2992) and PF299804 are the irreversible EGFR-TKIs with the most relevant data in the treatment of advanced NSCLC, as primary EGFR-targeted therapy and after resistance to reversible EGFR-TKIs. However, to date, the role of irreversible EGFR inhibitors remains to be defined.

New avenues for second-line treatment of metastatic non-small-cell lung cancer.

Platinum-based doublets are the standard first-line therapy for patients with advanced non-small-cell lung cancer, with approximately a third of patients obtaining an objective response with first-line chemotherapy and another 20-30% achieving temporary disease stabilization. However, all patients inevitably experience disease progression. Three agents are approved for treating patients who progress after one prior regimen: docetaxel, pemetrexed and erlotinib. Erlotinib is the only agent approved for use in the third-line setting. Although these agents have yielded similar outcomes in terms of anti-tumor activity and efficacy, they have different toxicity profiles, and some factors that can help in the choice among them have begun to emerge, such as smoking history and histotype. Several new molecularly targeted agents have shown activity in Phase II trials and may be integrated into second-line therapy as single agents or in combination with current agents in the future. In particular, the most encouraging data in this clinical setting have been reported with the antiangiogenetic drugs bevacizumab (already approved for use in the first-line setting), vandetanib and sunitinib. Phase III trials with these agents are ongoing.