Accuracy of clinical staging for T2N0 oesophageal cancer: systematic review and meta-analysis.

Oesophageal cancer is the sixth commonest cause of overall cancer mortality. Clinical staging utilizes multiple imaging modalities to guide treatment and prognostication. T2N0 oesophageal cancer is a treatment threshold for neoadjuvant therapy. Data on accuracy of current clinical staging tests for this disease subgroup are conflicting. We performed a meta-analysis of all primary studies comparing clinical staging accuracy using multiple imaging modalities (index test) to histopathological staging following oesophagectomy (reference standard) in T2N0 oesophageal cancer. Patients that underwent neoadjuvant therapy were excluded. Electronic databases (MEDLINE, Embase, Cochrane Library) were searched up to September 2019. The primary outcome was diagnostic accuracy of combined T&N clinical staging. Publication date, first recruitment date, number of centers, sample size and geographical location main histological subtype were evaluated as potential sources of heterogeneity. The search strategy identified 1,199 studies. Twenty studies containing 5,213 patients met the inclusion criteria. Combined T&N staging accuracy was 19% (95% CI, 15-24); T staging accuracy was 29% (95% CI, 24-35); percentage of patients with T downstaging was 41% (95% CI, 33-50); percentage of patients with T upstaging was 28% (95% CI, 24-32) and percentage of patients with N upstaging was 34% (95% CI, 30-39). Significant sources of heterogeneity included the number of centers, sample size and study region. T2N0 oesophageal cancer staging remains inaccurate. A significant proportion of patients were downstaged (could have received endotherapy) or upstaged (should have received neoadjuvant chemotherapy). These findings were largely unchanged over the past two decades highlighting an urgent need for more accurate staging tests for this subgroup of patients.