Potential utility of early metabolic response by 18F-2-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography in a selected group of breast cancer patients receiving preoperative chemotherapy.
BACKGROUND
To assess (18)F-2-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography's ((18)F-FDG-PET/CT) potential clinical utility to allow early treatment changes during preoperative chemotherapy (PCT) in patients with early/locally advanced breast cancer (BC).


METHODS
Sixty newly diagnosed early/locally advanced BC patients received 6-8 cycles of PCT. Optimal pathologic response (pR) was the absence of cancer cells in breast and axillary lymph nodes. All other conditions were defined as pathologic non-response (pNR). (18)F-FDG-PET/CT maximum standardised uptake value (SUV(max)) was measured at baseline and after 2 cycles of PCT. Metabolic response was defined as SUV(max) percentage changes (Δ-SUV) >50% and was compared with pR rates.


RESULTS
Thirteen (22%) patients achieved pR; according to immunohistochemistry, 16% of ER-positive/HER2-negative patients, 29% and 27% of HER2-positive and triple negative patients respectively achieved pR. (18)F-FDG-PET/CT showed the highest specificity (38%) and negative predictive value (100%) in ER-positive/HER2-negative patients. In this subgroup, at a median follow-up of 36.6 months, median disease-free survival was still not reached in metabolic responders while it was 37 months in metabolic non-responders (p=0.049).


CONCLUSIONS
Early metabolic non-response was always associated to pNR and poor prognosis in ER-positive/HER2-negative patients. In this subgroup, (18)F-FDG-PET/CT might be useful to select patients who will probably benefit from early therapeutic strategy modifications.
Medical Oncology Unit, S. Orsola-Malpighi University Hospital Bologna, Italy. giorgia.zucchini@studio.unibo.it
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G
Zucchini
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Quercia
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Zamagni
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Santini
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Taffurelli
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Fanti
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Martoni
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D017063:Outcome Assessment, Health Care / Q000379:methods; D049268:Positron-Emission Tomography; D057234:Preoperative Period; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D012074:Remission Induction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen