Evaluation of clinical examination, ultrasonography, mammography, and magnetic resonance imaging for detection of axillary metastases in overweight and obese women with early-stage breast cancer: a systematic review and meta-analysis

Accurate preoperative assessment of axillary lymph node status is essential for guiding treatment in early-stage breast cancer. Because clinical examination alone is often inadequate, imaging modalities such as axillary ultrasonography (AUS), mammography, and magnetic resonance imaging (MRI) are integral to axillary staging. Obese women with breast cancer have poorer oncologic outcomes than do their non-obese counterparts, which raises concerns about potential limitations in diagnostic performance due to a high body mass index (BMI). The objective of this study was to evaluate the diagnostic performance of clinical examination, AUS, mammography, and MRI in detecting axillary metastases in overweight and obese women with early-stage breast cancer. A systematic review and meta-analysis were conducted following the Preferred Reporting Items for a Systematic Review and Meta-Analysis of Diagnostic Test Accuracy guidelines. We included studies assessing the diagnostic accuracy of clinical and imaging modalities for detecting axillary metastasis in overweight and obese women. Methodological quality was assessed by using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Sensitivity and specificity data were extracted when available, and summary receiver operating characteristic curves were constructed. Nine studies met the inclusion criteria. The most frequently evaluated modality was AUS, which consistently demonstrated preserved diagnostic performance across weight groups; however, one retrospective cohort study reported that its negative predictive value decreases in parallel with increases in BMI. One study involving over 5,000 patients showed that the clinical examination is not significantly affected by the patient BMI. Mammography and MRI showed more variable results, with one study showing MRI performance potentially being impaired in overweight patients, although that study was rated as having a high risk of bias. Across studies, no substantial evidence supported the need for modifying diagnostic protocols based on BMI. Clinical examination and AUS continue to be reliable methods for axillary staging in overweight and obese women with early-stage breast cancer. Given one contradictory cohort study, negative AUS findings in obese patients should be interpreted with caution until standardized AUS criteria and prospective BMI-stratified studies are available. Further high-quality, prospective studies are needed in order to confirm these findings and to inform evidence-based refinements in staging protocols.