Abstract Purpose To describe the site-specific distribution of distant relapse detected by integrated ¹8F-FDG PET/contrast-enhanced CT (PET/ceCT) in breast cancer patients and to explore its association with molecular subtype and clinicopathological features. Methods This retrospective study included 177 postoperative breast cancer patients who underwent PET/ceCT during follow-up/restaging for suspected recurrence. Clinical and pathological data were extracted from a manually curated institutional database, including type of surgery, pathological T stage, pathological nodal status, histology, molecular subtype, PET/ceCT date, and PET/ceCT-detected site of relapse. Site-specific analyses were performed in patients with codable distant relapse. Results A PET/ceCT relapse-site entry was available in 141/177 patients (79. 7%), and 137/177 (77. 4%) had codable distant relapse. Molecular subtype was available in 166/177 patients (93. 8%). Bone was the most frequent site of distant relapse (81/137, 59. 1%), followed by lung (44/137, 32. 1%), distant lymph nodes (41/137, 29. 9%), and liver (40/137, 29. 2%) ; brain involvement was uncommon (8/137, 5. 8%). Single-site and multisite relapse were observed in 70/137 (51. 1%) and 67/137 (48. 9%) patients, respectively. Bone involvement was significantly more frequent in luminal than in non-luminal tumors (65/101, 64. 4% vs 11/29, 37. 9%; p=0. 018). Conclusion PET/ceCT disclosed non-random and biologically meaningful patterns of distant relapse in breast cancer. Bone-dominant relapse was the prevailing phenotype overall and was significantly associated with luminal disease, whereas non-luminal tumors showed relatively more visceral and multisite dissemination.
Chiaravalloti et al. (Thu,) studied this question.