Diagnostic and prognostic value of ¹⁸F-FDG PET/CT imaging in suspected recurrence of male breast cancer

Purpose Male breast cancer (MBC) is a rare malignancy, with recurrence being one of the main adverse predictors for prognosis. The aim of the study was to evaluate the diagnostic and predictive value of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET/CT in the setting of suspected recurrence of MBC. Patients and methods Retrospective analysis of PET/CT findings was performed in 23 previously treated, histologically proven patients with MBC (mean age: 59.3±10.9 years; range: 36-79 years) with suspected recurrence. Kaplan-Meier disease-specific survival analysis was made with respect to histological, hormonal profile as well as PET/CT findings. Results Of the 23 patients, 19 (82.6%) showed recurrence. Recurrence at primary site with/without regional/distant site recurrence was seen in 12 (52.2%) patients. Only metastatic recurrence without primary site was seen in seven (30.4%) patients. Bone was the most common site of distant metastasis (14/23) followed by lungs (9/23), liver (4/23), brain (2/23), and adrenal (1/23). No recurrence (regional/distant) was noted in 4/23 (17.3%) patients; however, three of them had ¹⁸F-FDG-avid soft tissue lesions in esophagus, rectum and tongue, correspondingly, confirmed as second primaries with histopathology. Disease-specific survival analysis yielded nodal (P=0.01) as well as distant metastases (P=0.02) as the main survival predictors on PET/CT. Lung (P=0.001), followed by liver (P=0.009), and skeletal (P=0.01) metastases were the most adverse survival predictive factors. Conclusion ¹⁸F-FDG PET/CT showed good diagnostic and prognostic utility in recurrent MBC. It was better than bone scan in evaluation of skeletal metastases. Most importantly, ¹⁸F-FDG PET/CT helped in early detection of second malignancy and their clinical management in studied patients.