Review question
Does screening individuals without symptoms using an Epstein-Barr virus blood test or nasopharyngoscopy (or both) reduce the mortality associated with nasopharyngeal cancer?
Background
Nasopharyngeal cancer is a rare cancer worldwide, but it is common in the Cantonese population of southern China. Due to its deep location in the nose and non-specific initial symptoms nasopharyngeal cancer is often detected late. While the prognosis for advanced nasopharyngeal cancer is very poor, early-stage nasopharyngeal cancer is potentially curable. Therefore early identification by screening might lead to improved outcomes. There are two common screening tests: the Epstein-Barr virus (EBV) blood test and nasopharyngoscopy (a procedure that allows the internal surfaces of the nose and throat to be examined with a fibre-optic instrument). Studying the benefits of screening for nasopharyngeal cancer started in the 1970s, but the value of this approach remains uncertain.
Study characteristics
This review intended to investigate the efficacy of a programme of screening and treatment using the EBV test and nasopharyngoscopy as a screening test for nasopharyngeal cancer. However, we did not identify any randomised or controlled clinical trials evaluating such a strategy.
Key results
There is a need for high-quality studies to determine the effectiveness of a screening programme for nasopharyngeal cancer, especially studies that assess long-term outcomes, such as mortality, and cost-effectiveness.
Quality of the evidence
This review is up to date to July 2015.
No data from RCTs or CCTs are available to allow us to determine the efficacy of screening for nasopharyngeal cancer, or the cost-effectiveness and cost-benefit of a screening strategy. High-quality studies with long-term follow-up of mortality and cost-effectiveness are needed.
Nasopharyngeal cancer is endemic in a few well-defined populations. The prognosis for advanced nasopharyngeal cancer is poor, but early-stage disease is curable and a high survival rate can be achieved. Screening for early-stage disease could lead to improved outcomes. Epstein-Barr virus (EBV) serology and nasopharyngoscopy are most commonly used for screening. The efficacy and true benefit of screening remain uncertain due to potential selection, lead-time and length-time biases.
To determine the effectiveness of screening of asymptomatic individuals by EBV serology and/or nasopharyngoscopy in reducing the mortality of nasopharyngeal cancer compared to no screening. To assess the impact of screening for nasopharyngeal cancer on incidence, survival, adverse effects, cost-effectiveness and quality of life.
The Cochrane Ear, Nose and Throat Disorders Group (CENTDG) Trials Search Co-ordinator searched the CENTDG Trials Register; Central Register of Controlled Trials (CENTRAL 2015, Issue 6); PubMed; EMBASE; CINAHL; Web of Science; Clinicaltrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 6 July 2015.
Randomised controlled trials (RCT) and controlled clinical trials (CCT) evaluating screening for nasopharyngeal cancer versus no screening. Randomisation either by clusters or individuals was acceptable.
We used the standard methodological procedures expected by The Cochrane Collaboration. Our primary outcome measure was nasopharyngeal cancer-specific mortality. Secondary outcomes were incidence of nasopharyngeal cancer by stage and histopathological classification at diagnosis, survival (two-year, three-year, five-year and 10-year), harms of screening (physical and psychosocial), quality of life (via validated tools such as the SF-36 and patient satisfaction), cost-effectiveness and all-cause mortality.
We identified no trials that met the review inclusion criteria. We retrieved 31 full-text studies for further investigation following the search. However, none met the eligibility criteria for a RCT or CCT investigation on the efficacy of screening for nasopharyngeal cancer.