Correlation of 18F-FDG/PET SUVmax, SUVmean, MTV, and TLG with HIF-1α in Patients with Colorectal Cancer

Prognostic significance of 18F-Fluorodeoxyglucose positron-emission tomography parameters in patients with biliary tract cancers: a meta-analysis

BACKGROUND AND OBJECTIVE

Numerous previous studies have assessed the prognostic role of 18F-fluorodeoxyglucose positron-emission tomography (18F FDG PET) in patients with biliary tract cancer (BTC), but those results were inconsistent. The present study aims to determine the predictive value of 18F FDG PET in BTC patients via a meta-analysis.

METHODS

The underlying studies related to 18F FDG PET and BTC patients` outcomes were searched and identified in the online databases. The interested parameters include total lesion glycolysis (TLG), metabolic tumor volume (MTV), primary tumor and metastatic lymph node (LN) maximum standardized uptake value (SUVmax), as well as change of SUVmax (ΔSUVmax) during treatment. Overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were considered as the primary endpoints. Hazard ratio (HR) and corresponding 95% confidence intervals (CIs) were defined as the effective measure and calculated by a pooled analysis. Publication bias was assessed by funnel plot, Bagg's and Egger's tests.

RESULTS

Totally, 23 studies involving 1478 patients were included in the present meta-analysis. After a pooled analysis, it revealed that a high SUVmax was significantly associated with a poor OS (HR:2.07, 95%CI: 1.74-2.46, P = 0.000) and DFS (HR: 2.28, 95%CI: 1.53-3.41, P = 0.000). In addition, an increased TLG level contributed to a shorter OS (HR:1.91, 95%CI: 1.26-2.90, P = 0.002) and DFS (HR: 4.34, 95%CI: 1.42-13.27, P = 0.01). Moreover, we confirmed that an elevated MTV was significantly associated with increased mortality (HR:2.04, 95%CI:1.26-3.31, P = 0.004) and disease relapse (HR: 3.88, 95%CI:1.25-12.09, P = 0.019) risks. Besides, the present study uncovered that increased ΔSUVmax could predict poor OS (HR:1.26, 95%CI:1.06-1.50, P = 0.008) instead of PFS (HR: 1.96, 95%CI: 0.82-4.72, P = 0.280). Lastly, we found that LN SUVmax did not link to OS (HR: 1.49, 95%CI: 0.83-2.68, P = 0.178). No obvious publication bias was detected in the present study.

CONCLUSION

18F FDG PET parameters, including SUVmax, TLG, MTV, and ΔSUVmax, could be applied as convenient and reliable factors for predicting BTC patients` outcomes.

Does high [18F]FDG uptake always mean poor prognosis? Colon cancer with high-level microsatellite instability is associated with high [18F]FDG uptake on PET/CT

OBJECTIVES

High-level microsatellite instability (MSI-high) is generally associated with higher F-18 fluorodeoxyglucose ([18F]FDG) uptake than stable microsatellite (MSI-stable) tumors. However, MSI-high tumors have better prognosis, which is in contrast with general understanding that high [18F]FDG uptake correlates with poor prognosis. This study evaluated metastasis incidence with MSI status and [18F]FDG uptake.

METHODS

We retrospectively reviewed 108 right-side colon cancer patients who underwent preoperative [18F]FDG PET/CT and postoperative MSI evaluations using a standard polymerase chain reaction at five Bethesda guidelines panel loci. The maximum standard uptake value (SUVmax), SUVmax tumor-to-liver ratio (TLR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured using SUV 2.5 cut-off threshold. Student's t-test or Mann-Whitney U test was performed for continuous variables, and χ2 test or Fisher's exact test was performed for categorical variables (p value of  < 0.05 for statistical significance). Medical records were reviewed for metastasis incidence.

RESULTS

Our study population had 66 MSI-stable and 42 MSI-high tumors. [18F]FDG uptake was higher in MSI-high tumors than MSI-stable tumors (TLR, median (Q1, Q3): 7.95 (6.06, 10.54) vs. 6.08 (4.09, 8.82), p = 0.021). Multivariable subgroup analysis demonstrated that higher [18F]FDG uptake was associated with higher risks of distant metastasis in MSI-stable tumors (SUVmax: p = 0.025, MTV: p = 0.008, TLG: p = 0.019) but not in MSI-high tumors.

CONCLUSION

MSI-high colon cancer is associated with high [18F]FDG uptake, but unlike MSI-stable tumors, the degree of [18F]FDG uptake does not correlate with the rate of distant metastasis.

CLINICAL RELEVANCE STATEMENT

MSI status should be considered during PET/CT assessment of colon cancer patients, as the degree of [18F]FDG uptake might not reflect metastatic potential in MSI-high tumors.

KEY POINTS

• High-level microsatellite instability (MSI-high) tumor is a prognostic factor for distant metastasis. • MSI-high colon cancers had a tendency of demonstrating higher [18F]FDG uptake compared to MSI-stable tumors. • Although higher [18F]FDG uptake is known to represent higher risks of distant metastasis, the degree of [18F]FDG uptake in MSI-high tumors did not correlate with the rate at which distant metastasis occurred.

18F‑fluorodeoxyglucose positron emission tomography predicts recurrence and histological grade of extrahepatic bile duct cancer

Malignant tumors in cholangiocarcinoma are diagnosed and staged using ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) and clinical analysis. However, comprehensive analysis, including pathological analysis, has not yet been sufficiently performed. In the present study, the maximum standardized uptake value (SUVmax) was calculated using FDG-PET and its relationship with clinicopathological factors was analyzed. The present study included 86 patients who underwent preoperative FDG-PET/computed tomography (CT) and did not receive chemotherapy among 331 patients with hilar and distal cholangiocarcinoma. Receiver operating characteristic analysis with recurrence events was used to determine the SUVmax cutoff of 4.9. Immunohistochemical staining of glucose transporter 1 (Glut1), hypoxia-inducible factor-1α and Ki-67 was performed for pathological analysis. The standardized uptake value (SUV)-high group (SUVmax ≥4.9) had a higher postoperative recurrence rate (P<0.046) and higher Glut1 and Ki-67 expression rates (P<0.05 and P<0.0001, respectively). Furthermore, SUVmax and Glut1 expression (r=0.298; P<0.01) and SUVmax and Ki-67 expression rates (r=0.527; P<0.0001) were positively correlated. The preoperative measurement of SUVmax by PET-CT is useful in predicting recurrence as well as cancer malignancy.

FDG-PET/CT in predicting aggressiveness of rectal cancer

Background

Treatment response varies significantly among rectal cancer patients. Tumor can show complete regression, stationary appearance, or even tumour progression during the treatment. It is also widely known that the rate of local recurrence is variable. Precise risk stratification of tumor aggressiveness is required for better per patient tailored treatment plan and predicting the overall prognosis of rectal cancer patients The aim of this study was to assess different parameters of baseline [18F] fluorodeoxyglucose positron emission tomography/computed tomography [(18F) FDG-PET/CT] as a non-invasive tool in predicting aggressiveness of the rectal cancer.

Results

Overall, 33 patients were included [19 moderately differentiated adenocarcinoma, 10 poorly differentiated adenocarcinoma and 4 mucinous adenocarcinomas (MAC)]. SUV estimates (SUV max, SUV mean) were greater in the moderately adenocarcinoma group (p = 0.003 and p = 0.019, respectively). MTV and TLG values were similar between the three histopathological groups (p = 0.763 and p = 0.701, respectively). There was no correlation between SUVmax of primary tumor and MTV (r = 0.034; p = 0.849). However, SUVmax and TLG were significantly correlated (r = 0.517; p = 0.002). Strong correlation between tumor size and MTV (r = 0.489; p = 0.003), and TLG (r = 0.506; p = 0.003) were observed. No significant association was found between MTV and TLG and the clinical stage of rectal cancer.

Conclusion

Baseline 18F-FDG PET/CT parameters cannot be used alone as a non-invasive diagnostic technique in assessing aggressiveness and prognosis in patients with primary rectal cancer, and further clinical studies are needed before considering the prognostic role of FDG-PET/CT in rectal cancer.