Harmonized pretreatment quantitative volume-based 18F-FDG PET/CT parameters for stage IV breast cancer prognosis. Multicenter study in Japan

Abstract

Objective: The prognostic value of harmonized pretreatment volume-based quantitative fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) parameters in metastatic breast cancer patients was investigated.

Subjects and methods: Records of 65 stage IV breast cancer patients, including 29 estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, 23 HER2-positive, and 13 triple-negative cases, from four different institutions were retrospectively reviewed. Harmonized standardized uptake value (SUVmax) of the primary tumor (pSUVmax), highest SUVmax of all malignant lesions (wSUVmax), whole-body metabolic tumor volume (WB MTV), and whole-body total lesion glycolysis (WB TLG) shown by pretreatment ¹⁸F-FDG PET/CT imaging were calculated. Cox proportional hazards model and log-rank test results were used to evaluate relationships among clinicopathological factors, volume-based quantitative ¹⁸F-FDG PET/CT parameters, progression-free survival, and overall survival (OS).

Results: Disease progression occurred in 54 patients and 28 died during a median follow-up period of 52.5 months (range 2.6-133.6 months). Univariate analysis of all cases showed associations of negative ER and progesterone receptor (PR) status (P=0.0025), and high T/N stage (P=0.037/P=0.019), pSUVmax (P=0.049), WB MTV (P=0.021), and WB TLG (P=0.0010) with significantly shorter OS. Multivariate analysis confirmed negative ER and PR status (hazard ratio [HR]: 6.42, 95% confidence interval [CI]: 2.27-19.38; P=0.0054), high T stage (HR: 5.10, 95% CI:1.96-18.61, P=0.0064) and WB TLG (HR: 4.69, 95% CI:1.67-12.79, P=0.049) as independent negative OS predictors. In two groups of ER-positive/HER2-negative and triple-negative, WB TLG had a significant association with death (P=0.021 and P=0.037, respectively) on univariate analysis. In a HER2-positive group, no independent negative OS predictors were observed.

Conclusion: In metastatic breast cancer patients, harmonized pretreatment quantitative volume-based ¹⁸F-FDG PET/CT parameters, especially whole-body TLG, are potential surrogate markers for prognosis.