Combined chemoradiation versus radiation therapy alone in locally advanced nasopharyngeal carcinoma: results of a meta-analysis of 1,528 patients from six randomized trials.

It is currently unclear whether the addition of chemotherapy to standard radiation therapy improves clinical outcome in patients with locoregionally advanced nasopharyngeal cancer. A meta-analysis was performed to evaluate the impact of integrating chemotherapy with external beam radiation therapy in this clinical setting. Using previously described methods, a protocol was developed outlining a meta-analysis examining the influence of chemoradiation versus radiation alone (control arm) in locoregionally advanced nasopharyngeal carcinoma. The outcomes of interest were disease-free/progression-free and overall survival. Literature search techniques, study inclusion criteria, and statistical procedures were prospectively defined. Data from all available randomized controlled trials was pooled using a fixed effects model (Peto). Results were expressed as summary relative risks. Statistical tests for heterogeneity were performed. If statistical heterogeneity was demonstrated, sensitivity analyses were performed to evaluate possible sources of heterogeneity across the included studies. The literature search identified six randomized controlled trials enrolling more than 1,500 patients. All trials compared standard radical external beam radiation therapy (control arm) with radiation plus chemotherapy delivered either adjuvantly, neoadjuvantly, or concurrently with radiation. Pooling all six studies using disease-free/progression-free survival as the endpoint demonstrated that the addition of chemotherapy to radiation therapy increased disease-free/progression-free survival by 37% at 2 years, 40% at 3 years, and 34% at 4 years after treatment. Likewise, the summary relative risk for overall survival at 2 years after treatment with the addition of chemotherapy to the treatment regimen was 0.80 (0.63-1.02), reflecting a 20% increase in 2-year survival. This finding was marginally non-statistically significant. Three- and 4-year survival was increased by 19% and 21%, respectively, with the data for 4-year survival being statistically significant. The addition of chemotherapy to standard radical radiation therapy for locoregionally advanced nasopharyngeal cancer increases both disease-free/progression-free and overall survival by 19 to 40% at 2 to 4 years after treatment, depending on the endpoint of interest. Future trials are needed to confirm these results and determine the most effective regimen for integrating chemotherapy with radiation therapy in this setting.