Effect of oral zinc sulphate in prevention of radiation induced oropharyngeal mucositis during and after radiotherapy in patients with head and neck cancers

ABSTRACT

Mucositis is a disturbing side effect of radiotherapy treatment for head and neck cancer. To date, no effective modality for its prophylaxis and treatment has been found. We performed this study to evaluate the efficacy of oral zinc sulphate in delaying the onset of oral and pharyngeal mucositis and decreasing their severity. A total of 58 patients who were treated for head and neck squamous cell carcinoma with radiotherapy or chemoradiotherapy were randomly assigned to receive oral zinc sulphate [220 mg] or an oral placebo 3 times a day during their radiotherapy course. Total radiation dose was 6000 cGy to 7000 cGy by conventional radiotherapy. Seventy nine percent of the patients also received concurrent chemotherapy. Oral and pharyngeal mucositis were scored according to an RTOG protocol. Time to onset of mucositis did not vary between the two groups. However, oral mucositis scores were less severe in the zinc group in weeks 4 to 6. The difference was statistically significant and the P values for weeks 4, 5 and 6 were 0.02, 0.007, and 0.012, respectively. Treatment interruptions in both groups were the same [four cases each] and all were due to dysphagia [pharyngeal mucositis]. Our results suggest that zinc is effective in reducing the severity of oral mucositis but not pharyngeal mucositis. Treatment interruptions were more frequently caused by pharyngeal mucositis which presented as dysphagia, rather than oral pain that was a manifestation of oral mucositis