Association between semiquantitative PET parameters and molecular subtypes of breast invasive ductal carcinoma.
BACKGROUND
Molecular subtypes of breast cancer have been proposed since 2012. The correlation between various baseline [18F]fluorodeoxyglucose ([18F]FDG) uptake parameters, including total lesion glycolysis (TLG), and molecular subtypes of primary breast cancer lesions in patients with invasive ductal cancer will be investigated.


METHODS
Staging [18F]FDG PET/CT for breast invasive ductal carcinoma were retrospectively evaluated. Breast lesions were examined for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation index (Ki-67). Breast tumors were classified into five molecular subtypes: Luminal A, Luminal B-HER2(-), Luminal B-HER2(+), HER2(+) and Basal or Triple Negative cancers. The correlations between tumor characteristics and PET semiquantitative data of primary breast lesion (SUVmean, SUVmax, Mean tumor volume (MTV), TLG) were assessed. Specific Breast Uptake Ratio (SBUR) is used as a new quantification method of breast uptake to correct for physiological background activity.


RESULTS
Fifty-eight patients were included. TLG was significantly higher in triple negative group when compared with luminal A (P<0.01). Significantly higher uptake was found in triple negative lesions when compared with luminal B-HER2(-) and luminal B-HER2(+) categories using SUVmax, SUVmean and TLG (all P<0.05). Conversely, no statistically significant difference for [18F]FDG uptake was observed between all other molecular subtypes. No value of SBUR in terms of correlation with histopathological parameters was demonstrated.


CONCLUSIONS
TLG was superior to SUVmax and SUVmean in differentiating between triple negative breast cancer lesions and all other molecular subtypes. SBUR was not different statistically between various molecular subtypes.
Regional Center of Nuclear Medicine, Department of Diagnostic Radiology and Vascular Radiology and Interventional and Nuclear Medicine, University Hospital of Pisa, Pisa, Italy - chiacchioserena@gmail.com.
Serena
S
Chiacchio
Unit of Radiotherapy and Nuclear Medicine, Istituto Oncologico Veneto (IOV), IRCC, Padua, Italy.
Laura
L
Evangelista
University of Jordan, Amman, Jordan.
Abedallatif
A
Alsharif
Regional Center of Nuclear Medicine, Department of Diagnostic Radiology and Vascular Radiology and Interventional and Nuclear Medicine, University Hospital of Pisa, Pisa, Italy.
Gianpiero
G
Manca
Health Physics Division, University Hospital of Pisa, Pisa, Italy.
Fabio
F
DI Martino
Unit of Medical Physics, Istituto Oncologico Veneto (IOV), IRCC, Padua, Italy.
Anna
A
Negri
Regional Center of Nuclear Medicine, Department of Diagnostic Radiology and Vascular Radiology and Interventional and Nuclear Medicine, University Hospital of Pisa, Pisa, Italy.
Manuel
M
Tredici
Unit of Radiotherapy and Nuclear Medicine, Istituto Oncologico Veneto (IOV), IRCC, Padua, Italy.
Anna R
AR
Cervino
Regional Center of Nuclear Medicine, Department of Diagnostic Radiology and Vascular Radiology and Interventional and Nuclear Medicine, University Hospital of Pisa, Pisa, Italy.
Giulia
G
Puccini
Unit of Medical Physics, Fondazione &quot;G. Monasterio&quot;, Pisa, Italy.
Elena
E
Filidei
Unit of Senology, University Hospital of Pisa, Pisa, Italy.
Matteo
M
Ghilli
Section of Pathology, Department of Surgery, University of Pisa, Pisa, Italy.
Antonio G
AG
Naccarato
Unit of Senology, University Hospital of Pisa, Pisa, Italy.
Manuela
M
Roncella
Regional Center of Nuclear Medicine, Department of Diagnostic Radiology and Vascular Radiology and Interventional and Nuclear Medicine, University Hospital of Pisa, Pisa, Italy.
Duccio
D
Volterrani
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies
D019788:Fluorodeoxyglucose F18