Accurate loco-regional staging is essential in the management of rectal cancer, guiding decisions regarding surgical resection, neoadjuvant therapy, and endoscopic interventions. Endoscopic ultrasound (EUS) is widely used for evaluating tumour depth (T stage) and regional lymph node involvement (N stage), but reported diagnostic performance varies across studies. This systematic review and meta-analysis aimed to synthesize evidence on the accuracy of EUS for staging rectal cancer.

A comprehensive literature search was performed in MEDLINE, Embase and Cochrane Library until May 27, 2025. We identified primary studies reporting the diagnostic performance of conventional EUS (linear or radial) for rectal cancer staging compared with histopathology as the reference standard. We excluded studies using miniprobe or non-conventional EUS techniques, as well as patients who received neoadjuvant radiochemotherapy.  Pooled sensitivity, specificity, PPV, NPV, accuracy, overstaging and understaging for T and N staging were calculated using a bivariate random-effects model. Heterogeneity was assessed with the I2 statistic.

Twelve studies comprising 1,216 patients were included for T-stage evaluation, and nine studies comprising 451 patients for N-stage evaluation. Of the four retrospective and eight prospective studies, most used a radial probe (n=9), with three using a linear probe. Ten studies included rectal adenocarcinoma.

EUS demonstrated high specificity for early disease (T1: 0.98; 95% CI 0.93–1.00) with corresponding sensitivity of 0.77 (95% CI 0.65–0.87) and accuracy of 0.94 (95% CI 0.89–0.98). T2 staging showed moderate sensitivity (0.77; 95% CI 0.67–0.86) and specificity (0.85; 95% CI 0.78–0.91), with overstaging occurring in 14% of cases. Performance was also good with more advanced T3 (sensitivity 0.86; specificity 0.91; accuracy 0.88), and T4 disease (sensitivity 0.84; specificity 1.00; accuracy 0.98). Understaging was most common with T4 lesions (0.19; 95% CI 0.01–0.48). For nodal staging, EUS demonstrated lower sensitivity (0.64; 95% CI 0.46–0.78) and specificity (0.80; 95% CI 0.61–0.95), with an overall accuracy of 0.74 (95% CI 0.66–0.81).

In rectal cancer, EUS provides reliable staging accuracy for T1 and advanced rectal lesions (T3/4), supporting its role in selecting candidates for local excision and informing neoadjuvant therapy decisions. However, EUS demonstrates limited performance for T2 lesions and nodal staging and hence, findings support integrating EUS with pelvic MRI and selective pathological confirmation to optimize staging-directed treatment planning.