The clinical implications of FDG-PET/CT differ according to histology in advanced gastric cancer

Abstract

Background The prognostic impact of preoperative 18 F-FDG PET/CT in advanced gastric cancer (AGC) remains a matter of debate. This study aims to evaluate the prognostic impact of SUV max in preoperative 18 F-FDG PET/CT of AGC according to histologic subtype, with a focus on the differences between tubular adenocarcinoma and signet ring cell (SRC) carcinoma. Methods As a discovery set, a total of 727 AGC patients from prospective database were analyzed according to histologic subtype with Cox proportional hazard model and p-spline curves. In addition, another 173 patients from an independent institution was assessed as an external validation set. Results In multivariate analysis, high SUV max in preoperative 18 F-FDG PET/CT of AGC was negatively correlated with disease-free survival (DFS) and overall survival (OS) in patients with diffuse type (DFS: HR 2.17, P < 0.001; OS: HR 2.47, P < 0.001) or SRC histology (DFS: HR 2.26, P = 0.005; OS: HR 2.61, P = 0.003). This negative prognostic impact was not observed in patients with intestinal type or well or moderately differentiated histology. These findings have been consistently confirmed in a validation set. The p-spline curves also showed a gradual increase in log HR as SUV max rises only for SRC histology and for diffuse-type AGC. Finally, a novel predictive model for recurrence of AGC with diffuse type or SRC histology was generated and validated based on the preoperative SUV max . Conclusions Preoperative high SUV max of AGC is a poor prognostic factor in those with diffuse type or SRC histology. This study is the first to demonstrate the differential prognostic impact of preoperative PET/CT SUV max in AGC according to histologic subtype and provide a clue to explain previous discrepancies in the prognostic impact of preoperative PET/CT in AGC. Prospective studies are required to validate the role of preoperative SUV max in AGC.

Primary tumor standardized uptake value (SUVmax) measured on 18F-FDG PET/CT and mixed NSCLC components predict survival in surgical-resected combined small-cell lung cancer

“…A cohort study of 5002 patients (Nicholson et al 2016 ) has confirmed the prognostic value of both clinical and pathologic TNM staging in SCLC patients with limited-stage disease. Several studies have reported that high SUV max values in 18 F-FDG PET/CT as a prognostic factor are associated with a poorer clinical outcome in patients with various malignancies, such as head and neck cancer, renal cell carcinoma, cervical cancer, gastric cancer and NSCLC (Bille et al 2013 ; Brunette et al 2018 ; Chon et al 2019 ; Ha et al 2017 ; Pankowska et al 2019 ). Kwon et al ( 2016 ) conducted a retrospective study and enrolled 59 limited-stage SCLC patients who underwent pretreatment 18 F-FDG PET/CT and found that highest SUV max is an independent prognostic factor for survival in limited-stage SCLC patients.…”

Preoperatively Treated Diffuse-Type Gastric Adenocarcinoma: Glucose vs. Other Energy Sources Substantially Influence Prognosis and Therapy Response

“…There are only two studies that seem to address the role of PET-CT in GAC. An excellent study by Chon H et al [ 22 ]. focused on 727 localized GAC patients who underwent surgery as primary therapy but all had baseline FDG-PET [ 22 ].…”

“…An excellent study by Chon H et al [ 22 ]. focused on 727 localized GAC patients who underwent surgery as primary therapy but all had baseline FDG-PET [ 22 ]. They also found that in the subset of patients with dGAC or SRC, high SUV leads to poor OS but the SUV avidity does not affect outcome in well/moderately differentiated GACs, even poorly differentiated GACs, or iGACs.…”

“…The potentially low FDG avidity in dGAC is attributed to several factors, including the low-density diffuse infiltration of GAC cells, existence of extracellular or intracellular metabolically inert mucus content, use of glutamine as fuel rather than glucose, and low expression level of glucose transporter 1 (GLUT-1) [ 20 , 21 ]. Low avidity on PET has been reported as a beneficial prognosticator in dGAC patients who had primary surgery [ 22 ]. In the West, preoperative therapy is commonly given for localized GACs (including dGACs), we chose to determine the value of baseline FDG-PET in localized dGACs treated preoperatively as reported before [ 23 ].…”

Gastric cancer and image-derived quantitative parameters: Part 2—a critical review of DCE-MRI and 18F-FDG PET/CT findings

“…We found eight studies on 18 F-FDG PET/CT and prognosis in GC (Table 4). Significant results on the relationship between SUV max and SUV mean and overall survival were reported by seven of them [35–38, 40–42], even though each study used different SUV max and SUV mean cut-offs (Table 4). The study that did not show any significant difference in SUV max and SUV mean with regard to prognosis was performed by Grabinska and colleagues [39].…”