Activity of chemotherapy in the palliative treatment of salivary gland tumors: review of the literature

Chemotherapy is sometimes used as palliation for patients with salivary gland tumors not amenable to curative treatment. However, if chemotherapy improves survival is unknown. To identify some prognostic parameters in this disease, we conducted an extensive review of the literature. The prognostic value of the baseline clinical characteristics and the different chemotherapy regimens used was assessed using the Cox proportional hazards regression model on the available individual data. In addition, the effect of the different chemotherapy drugs on median survival time was evaluated using meta-weighted linear regression with dummy covariates referring to each chemotherapy drug. The total number of patients included in these studies that fit our inclusion criteria was 264 patients. By reviewing carefully the papers and by contacting the different authors, we were able to retrieve the individual data of 205 patients. In the multivariate Cox analysis, only the use of platinum-based chemotherapy was identified as an independent predictor of an increased survival (P = 0.01). These results were confirmed in a meta-analysis where median survival was increased by 2.5 (95% IC:0.7-4.4) and 4.9 (95% IC:0.45-9.4) months for patients treated with platinum (P = 0.007) and anthracyclin-based (P = 0.03) chemotherapy, respectively. Although exploratory, our analysis suggests that treatment with a platinum-based chemotherapy regimen may be an independent factor of better survival for patients with incurable salivary gland neoplasms.