Background: In the case of advanced oesophageal cancer (AOC) patients, whose prognosis is very poor, most clinical practice guidelines (CPGs) recommend the use of anticancer drugs over best supportive care (BSC) alone, but these recommendations may not have taken into account all the available evidence. Objective: To assess the agreement over the last 30 years between available evidence and related CPGs regarding treatments with anticancer drugs versus BSC alone for AOC.
Methods: We conducted a historical review in three phases: 1) After conducting an overview of systematic reviews (SRs) and confirming that no SR existed to address our research question, we conducted a new SR to identify all relevant randomised clinical trials (RCTs) that evaluated anticancer drugs versus BSC alone for AOC; 2) We identified the most relevant international CPGs from the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO), and the National Institute for Health and Care Excellence (NICE); and 3) We compared whether the recommendations proposed in the CPGs were supported by the previously identified RCTs.
Results: We identified 13 relevant RCTs. The first two were published in the early 1990s, but it was not until 20 years later that new studies were published. We retrieved 12 relevant international CPGs: 8 from ESMO, 3 from ASCO, and 1 from NICE, published between 2005 and 2022. None of the CPGs referenced the identified RCTs, and, instead, they considered other evidence not directly related to the clinical question (Figure 1).
Conclusions: There is a mismatch between relevant research and the evidence considered by CPGs for making their recommendations about anticancer drugs versus BSC alone for AOC. This mismatch could have biased the formulation of recommendations towards favouring the use of anticancer drugs over the BSC alone. Relevance and importance to patients: AOC patients should be aware that anticancer drugs proposed to them may not be fully supported by the available evidence, even if they are recommended by relevant international CPGs. This lack of concordance could lead to inappropriate overtreatment, i.e., the prescription of unnecessary treatments with an uncertain ratio of benefits and harms.