Esophageal cancer: a critical evaluation of systemic second-line therapy

The objective of this article was to review clinical trials that used antineoplastic second-line chemotherapy and/or targeted therapies in patients with esophageal cancer after first-line therapy. Computerized (MEDLINE) and manual searches were performed to identify articles published on this topic between 1996 and 2011. Twenty-five published trials and four abstracts presented at scientific meetings were identified. A total of 10 trials included only patients with squamous cell carcinomas (SCCs), four focused exclusively on adenocarcinoma (AC), the remaining 15 studies included both SCC and AC. The majority of trials (17 of 29) used docetaxel in combination with platinum analogs, eight used single-agent cytotoxic chemotherapy, and six evaluated targeted therapies. The numbers of patients were relatively small, ranging from eight to 55 patients. The response rates were generally low (between 0% and 39%), with only two small studies reporting objective responses of 50% and 63%, respectively. Time to progression ranged from 1.4 to 6.2 months, and the overall survival was disappointing at 4.0 to 11.4 months. Approximately 40% of patients who experience progressive disease after first-line chemotherapy are able to undergo second-line treatment. On the basis of data published so far, no standard second-line therapy has emerged. Future research will need to focus on individual therapy strategies such as genetic receptor mutations to increase the therapeutic outcome.