title: Pre-chemotherapy 18F-FDG PET/CT upstages nodal stage in stage II-III breast cancer patients treated with neoadjuvant chemotherapy.
abstract: In breast cancer patients treated with neoadjuvant chemotherapy (NAC) the number of tumor-positive nodes can no longer reliably be determined. Furthermore, ultrasound (US) seems suboptimal for the detection of N3-disease. Therefore we assessed the proportion of breast cancer patients treated with NAC in which pre-chemotherapy 18F-FDG PET/CT detected ≥4 axillary nodes or occult N3-disease, upstaging nodal status and changing risk estimation for locoregional recurrence (LRR). Conventional regional staging consisted of US with fine needle aspiration and/or sentinel lymph node biopsy. Patients were classified as low-risk (cT2N0), intermediate-risk (cT0N1, cT1N1, cT2N1, cT3N0), or high-risk (cT3N1, cT4, cN2-3) for LRR. The presence and number of FDG-avid nodes were evaluated and the proportion of patients that would be upstaged by PET/CT, based on detection of ≥4 FDG-avid axillary nodes defined as cN2(4+) or occult N3-disease, was calculated. In total, 87 of 278 patients were considered high-risk based on conventional staging. PET/CT detected occult N3-disease in 5 (11 %) of 47 low-risk patients. In 144 intermediate-risk patients, PET/CT detected ≥4 FDG-avid nodes in 24 (17 %) patients and occult N3-disease in 22 (15 %) patients, thereby finally upstaging 38 (26 %) of intermediate-risk patients. Of 43 (23 %) upstaged patients, 18 were ypN0, 12 were ypN1, and 13 were ypN2-3. Pre-chemotherapy PET/CT is valuable for selection of breast cancer patients at high risk for LRR. In our population, 23 % of patients treated with NAC were upstaged to the high-risk group based on PET/CT information, potentially benefiting from regional radiotherapy.
authors.affiliation: Department of Nuclear Medicine, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands, b.koolen@nki.nl.
authors.forename: Bas B
authors.initials: BB
authors.lastname: Koolen
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.forename: Wouter V
authors.initials: WV
authors.lastname: Vogel
authors.forename: Marie Jeanne T F D
authors.initials: MJ
authors.lastname: Vrancken Peeters
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Rodenhuis
authors.forename: Emiel J Th
authors.initials: EJ
authors.lastname: Rutgers
authors.forename: Paula H M
authors.initials: PH
authors.lastname: Elkhuizen
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18