Clinicopathological and prognostic relevance of uptake level using 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer

Objective: Using integrated ¹⁸F-fluorodeoxyglucose positron emission tomography/computedtomography fusion imaging (¹⁸F-FDG PET/CT), the clinical significanceof ¹⁸F-FDG uptake was evaluated in patients with primary breastcancer. Methods: Clinicopathological correlation with the level of maximum standardizeduptake values (SUV) 60 min obtained from preoperative ¹⁸F-FDGPET/CT were examined in 152 patients with primary breast cancer.The prognostic impact of the level of SUV was explored usingsimulated prognosis derived from computed program Adjuvant!in 136 (89%) patients with invasive ductal carcinoma (IDC). Results: High SUV level was significantly correlated with tumor invasivesize (2 cm) (P <0.0001), higher score of nuclear grade (P<0.0001), nuclear atypia (P <0.0001) and mitosis counts(P <0.0001), negative hormone receptor status (P = 0.001),high score of c-erbB-2 expression (P = 0.006), lymph node metastasis(P = 0.002), and IDC in comparison with invasive lobular carcinoma(P = 0.004). Multivariate analyses showed tumor invasive size,nuclear grade and estrogen receptor negativity were significantlycorrelated with SUV in primary breast cancer (P <0.0001,<0.0001,and <0.012, respectively), and nuclear grade was significantlycorrelated with SUV in tumors of invasive size 2 cm or less(P <0.0001). Tumors with high SUV (cutoff value 4.0) showedhigher relapse and mortality rate compared to those with lowSUV (P <0.0001). Conclusions: High uptake of ¹⁸F-FDG would be predictive of poor prognosisin patients with primary breast cancer, and aggressive featuresof cancer cells in patients with early breast cancer. ¹⁸F-FDGPET/CT could be a useful tool to pretherapeutically predictbiological characteristics and baseline risk of breast cancer.