Interventions for the treatment of oral and oropharyngeal cancers: surgical treatment

Abstract

Background: Oral and oropharyngeal cancers can be managed by surgery alone or with any combination of radiotherapy, chemotherapy and immunotherapy/biotherapy. Opinions on the surgical treatment, the optimal combinational therapy and the sequence of treatments in combinational therapy varies enormously.

Objectives: To determine which surgical treatment modalities for oral and oropharyngeal cancers lead to the best outcomes compared with other surgical, radiotherapy, chemotherapy or immunotherapy/biotherapy combinations.

Search strategy: Electronic search of the Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE, OLDMEDLINE, EMBASE, AMED and the National Cancer Trials Database. Reference lists from relevant articles were searched and the authors of eligible trials were contacted. Date of the most recent searches: July 2007.

Selection criteria: Randomised controlled trials of surgery alone or in combination with chemotherapy, radiotherapy or immunotherapy/biotherapy for the treatment of primary oral or oropharyngeal cancer or both.

Data collection and analysis: A minimum of two review authors conducted data extraction. Risk ratios were calculated for dichotomous outcomes at different time intervals, and hazard ratios were extracted or calculated for disease-free survival, total mortality, and disease-related mortality. Additional information from trial authors was sought. Data on adverse events were collected from the trial reports.

Main results: Thirty-one trials satisfied the inclusion criteria, only 13 of which were assessed as low risk of bias. Trials were grouped into 12 main comparisons. There were no trials that compared different surgical modalities of the primary tumour itself. However, there were a number of trials comparing different approaches to managing the cervical lymph nodes. The majority of treatment regimens under evaluation were surgery in combination with other modalities. As individual treatment regimens within each comparison varied, meta-analysis was inappropriate in most instances. Only two trials could be pooled, comparing concomitant radio/chemotherapy (with surgery) versus radiotherapy (with surgery). A statistically significant difference was shown for disease-free survival (hazard ratio 0.77, 95% confidence interval (CI): 0.64 to 0.92) and total mortality (hazard ratio 0.78, 95% CI: 0.64 to 0.95) in favour of the concomitant chemotherapy and radiotherapy (with surgery) arm. No other treatment regimens showed consistent statistically significant results across the outcomes measured.

Authors' conclusions: There is some evidence that concomitant radio/chemotherapy (with surgery) is more effective than radiotherapy (with surgery) and may benefit outcomes in patients with more advanced oral and oropharyngeal cancers. As these trials were based on head and neck studies, future studies should evaluate this treatment regimen specifically in oral and oropharyngeal cancers separately and also address tumour staging and its impact on outcomes. In general, future studies are encouraged to evaluate site-specific and stage-specific data for oral and oropharyngeal cancers. Future trials should include health-related quality of life assessment as an outcome measure. There is a need for a consolidated standardised approach to reporting adverse events.