Diagnostic accuracy of lateral lymph node metastasis for locally advanced rectal cancer after neoadjuvant therapy: a systematic review and meta-analysis.

BACKGROUND

The optimal criteria for lateral lymph node dissection (LLND) in rectal cancer following neoadjuvant therapy remain undefined. This systematic review and meta-analysis evaluated the diagnostic accuracy of lateral lymph node metastasis (LLNM) to refine criteria for selective LLND.

RESEARCH DESIGN AND METHODS

A systematic search of PubMed, Embase, and the Cochrane Library (10 August 2024) identified studies assessing magnetic resonance imaging (MRI)-based LLNM detection in patients with rectal cancer who underwent neoadjuvant therapy and radical surgery. Studies reporting MRI-based LLNM assessments with pathological confirmation were included. Non-English studies, reviews, case reports, and those lacking lymph node size data were excluded. The risk of bias was assessed using QUADAS-2. Pooled sensitivity, specificity, and diagnostic odds ratios were estimated using hierarchical summary receiver operating characteristic curve (HSROC) analysis.

RESULTS

Eleven studies met the inclusion criteria. All used MRI-based size assessments. The pooled sensitivity and specificity were 0.776 (95% CI: 0.639-0.872) and 0.694 (95% CI: 0.541-0.813), respectively, with an HSROC area under the curve (AUC) of 0.801.

CONCLUSIONS

MRI is the most widely used modality for diagnosing LLNM in rectal cancer patients who have undergone neoadjuvant therapy, with size criteria being the most commonly applied.

REGISTRATION

PROSPERO (CRD42024578499).