PET-CT for Staging in Early Breast Carcinoma: Insights from our Institute Experience - a Prospective Cohort Study

Current guidelines do not routinely recommend PET-CT for staging early breast cancer (EBC). This study evaluates PET-CT as a single-modality tool for detecting occult metastases in EBC, stratified by molecular subtypes. A prospective cohort study of 151 biopsy-proven EBC patients (cT1-T2 NO-N1, cT3-N0) underwent staging PET-CT. Patients were stratified into LOW-RISK (HR+/HER2-; n = 88) and HIGH-RISK (TNBC/HER2+; n = 63) groups. The primary endpoint was PET-CT-driven treatment modification. Statistical analysis used chi-square tests (SPSS v28). PET-CT altered management in 24/151 patients (15.89%). Findings included distant metastases (bone: 2.6%, lung nodules: 1.32%), extra-axillary nodal involvement (internal mammary: 3.31%, contralateral axillary: 1.32%), and synchronous malignancies (endometrial: 2.6%, ovarian/renal/contralateral breast: 0.6% each). High-risk subtypes had significantly higher PET-CT-detected events (17/63; 11.2%) versus low-risk (7/88; 4.6%) (p = 0.0034). PET-CT in EBC upstaged disease or revealed synchronous malignancies in 15.89% prompting modification of treatment. High risk (TNBC/HER2+) molecular subtypes demonstrated significantly greater benefit, supporting PET-CT use in EBC despite guideline limitations while the Low risk (HR +/HER2 - ) molecular types can be staged in the conventional way.