Toxicity increases with combined chemo/radiation treatments for nasopharyngeal carcinoma

Combining radiation and chemotherapy has been the long-standing standard treatment for nasopharyngeal carcinoma, ever since the Intergroup-0099 Study in the early nineties showed increased three-year overall survival for patients treated with the combined therapies. But there have been few data on the potential toxicities of these treatments. The NPC-990 Trial is the first study with data on toxicities and causes of non-cancer death.

To compare the toxicity profile and overall survival of patients treated with radiation and chemotherapy compared to those treated with radiation therapy alone, Anne W.M. Lee of the Hong Kong Nasopharyngeal Cancer Study Group and colleagues, compared two randomly assigned treatment groups of patients with advanced nasopharyngeal carcinoma: in the first group 172 patients were treated with radiation alone, compared to a second group of 176 patients treated with both radiation and chemotherapy.

Patients from five hospitals in Hong Kong and Canada were enrolled in the trial, which lasted from March 1999, until February 2004. Patients were followed up at least every three months during the first three years, and then every six months thereafter until death.

The researchers found that the patients taking combined radiation and chemotherapy experienced a statistically significant reduction in deaths due to disease progression. But they also experienced a statistically significant increase in deaths due to treatment-related toxicities and other causes. Indeed, there was an acute toxicity rate of 83%, compared to 53% in the radiation therapy group alone.

The authors also reported a "worrisome increase" in non-cancer deaths in the combined therapies group, including infection, second malignancy and suicide. This finding "could narrow the actual magnitude of survival gain," they write.