Prognostic stratification of baseline PET metabolic parameters combined with Bcl-2/c-Myc dual expression in patients with primary gastrointestinal diffuse large B-cell lymphoma / 中华核医学与分子影像杂志

ABSTRACT

Objective:To explore whether baseline PET metabolic parameters combined with B-cell lymphoma-2 (Bcl-2)/cellular-myelocytomatosis viral oncogene (c-Myc) dual expression (DE) can improve the prognostic stratification of patients with primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL).Methods:From March 2011 to November 2019, 74 patients (33 males, 41 females; age: 20-87 years) pathologically diagnosed with PGI-DLBCL prior to treatment in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School and the First Affiliated Hospital of Nanjing Medical University were retrospectively included. Baseline PET/CT scans were calculated automatically using the boundaries of voxels presenting a SUV max≥2.5, and metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were determined. Expressions of Bcl-2 and c-Myc were detected at protein levels by immunohistochemistry (IHC). A predicting model comprised of MTV and DE was constructed and patients were divided into 3 groups, including low-risk group (low MTV and non-DE), mediate-risk group (high MTV or DE) and high-risk group (high MTV and DE). The distributions of progression-free survival (PFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method, log-rank test and Cox proportional hazards model. Results:Of 74 patients, 20 relapsed or progressed, 13 died, and 29.7%(22/74) patients were DE positive. Multivariate analysis revealed that MTV (hazard ratio ( HR)=9.110, 95% CI: 1.429-18.615, P=0.012) and DE ( HR=9.837, 95% CI: 1.690-57.260, P=0.011) were independent predictors of PFS, while MTV ( HR=12.470, 95% CI: 3.356-46.336, P<0.001) was the only independent predictor of OS. In the predicting model for PFS, low-risk group ( n=42) and mediate-risk group ( n=20) exhibited significant difference ( χ2=7.84, P=0.005), and mediate-risk group and high-risk group ( n=12) also exhibited significant difference ( χ2=18.72, P<0.001). Conclusions:MTV and DE can independently predict PFS of patients with PGI-DLBCL, and MTV can independently predict OS. The predicting model for PFS combining MTV with DE may further improve the ability of clinicians to stratify patients in terms of differential prognoses.