Chemotherapy for advanced non-small cell lung cancer: Past, present, and future

Until recently, chemotherapeutic intervention in advanced and metastatic non-small cell lung cancer (NSCLC) has been viewed with a certain degree of nihilism. Although meta-analysis of randomized clinical studies from the 1970s and 1980s comparing cisplatin-based chemotherapy to best supportive care in metastatic NSCLC showed improvement in survival, it was modest at best. A number of novel agents have been developed with significant activity against NSCLC in the past 5 to 6 years and are being incorporated into the therapy of this disease. These agents include paclitaxel, docetaxel, vinorelbine, gemcitabine, and irinotecan. Clearly there has been improvement in response rates, and in some cases the responses have been durable with an increase in the number of 1- and 2-year survivors. The next generation of studies has evaluated combinations of these novel agents with either cisplatin or carboplatin for patients with NSCLC and the results have been provocative, with 1-year survival rates as high as 54%: A randomized phase III study of the Eastern Cooperative Ontology Group has shown the superiority of paclitaxel-cisplatin regimens over etoposide-cisplatin for patients with advanced and metastatic NSCLC. The vinorelbine-cisplatin regimen has also proven to have significant, albeit modest: benefit in survival when compared with cisplatin alone. These combination regimens have now become the reference regimens in ongoing randomized studies. There is continued interest in developing new agents, or selective approaches that effect novel targets with the hope of showing improved therapeutic activity. Some of these approaches include gene therapy, monoclonal antibodies, and introduction of antisense oligodeoxy-nucleotides. With better understanding of the molecular and cellular biology of lung cancer, the hope for the future is to combine the mechanistic approaches with new drug development to define an effective, optimal, and definitive regimen for NSCLC.