Effects of DNA Ploidy and S-Phase Fraction on Fluorine-18 FDG Uptake of Primary Breast Cancer Lesions

Abstract

BackgroundFlow cytometry (FCM) evaluating DNA content is emerging as the tool to monitor cell proliferation and malignant potential in several cancers such as stomach, lung, and salivary gland tumor. The purpose of this study was to correlate 18F-FDG uptake of dual–time-point (DTP) positron emission tomography (PET) imaging with DNA ploidy and S-phase fraction (SPF) in primary breast cancer lesions. Patients and MethodsSeventy-two consecutive female patients (mean age ± SD, 52.7 ± 11.1 years; range, 28-81 years) had undergone 18F-FDG DTP PET/computed tomography (CT) imaging for staging of breast malignancy in our institution during a 5-month period. FCM was performed on fresh-frozen samples of specimens obtained from surgery. 18F-FDG uptake was then compared with DNA content. ResultsForty-four malignant lesions were included in this study. On FCM, DNA aneuploidy was detected in 14 lesions (31.8%). The maximum standardized uptake values (SUVmax1 and SUVmax2) (SUVmax1, 6.8 ± 4.6 vs. 3.4 ± 2.4; P = .017), (SUVmax2, 7.9 ± 5.7 vs. 3.6 ± 2.7; P = .015) and retention index (RI) (12.8 ± 11.6 vs. 2.4 ± 10.8; P = .010) were significantly higher in DNA aneuploidy cancer than in DNA diploidy cancer. The value of RI (11.3 ± 11.5 vs. 2.6 ± 11.2; P = .022) was significantly higher in high SPF (> 15%) breast cancer than in low SPF (≤ 15%) breast cancer. ConclusionsHigh 18F-FDG uptake in breast cancer might be an indicator of DNA aneuploidy and high SPF. We propose that 18F-FDG PET/CT imaging may be a noninvasive and useful tool for predicting the DNA content in breast cancer.