Metabolic Signature on 18F-FDG PET/CT, HER2 Status, and Survival in Gastric Adenocarcinomas

Predictive significance of 18F-FDG PET/CT metabolic parameters for the expression level of HER2 in gastric cancer

Objective

To investigate the predictive value of pertinent metabolic parameters of 18F-FDG PET/CT in relation to the expression level of human epidermal growth factor receptor 2 (HER2) in patients with gastric cancer.

Materials and methods

The data was retrospectively acquired from 105 patients who had been pathologically diagnosed gastric cancer prior to treatment at our institution, including clinical data, laboratory test results, histological information, 18F-FDG PET/CT metabolic parameters (including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), peak standardized uptake value (SUVpeak), SUVmax normalized by lean body mass (SULmax), SUVmean normalized by lean body mass (SULmean), SUVpeak normalized by lean body mass (SULpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)), and HER2 expression level, from January 2018 to December 2022. The correlation between 18F-FDG PET/CT metabolic parameters and HER2 expression level was examined, and the predictive value of these measures for HER2 expression level was investigated.

Results

Among the 105 patients, 27 exhibited positive HER2 expression, while 78 demonstrated negative HER2 expression. Significant differences in MTV and TLG between patients exhibiting positive and negative HER2 expression (P < 0.05). The best cut-off values for MTV and TLG were 20.3 cm³ and 72.3 g, yielding accuracy rates of 90.2% and 89.0% for predicting positive HER2 expression, respectively. Our further grouped study shows that in the gastric adenocarcinoma and Lauren classification groups, MTV was significantly negatively correlated with HER2 positivity. Notably, in mixed tumors, the AUC value reached as high as 0.85.

Conclusions

The negative correlations between MTV/TLG and HER2 status demonstrated that HER2-positive tumors are associated with reduced metabolic burden, providing imaging biomarkers for clinical prognostic assessment. Notably, subgroup analysis in gastric adenocarcinoma and Lauren classification subgroups revealed significant negative associations between MTV and HER2 positivity, highlighting MTV's potential utility in predicting HER2 expression across histological subtypes of gastric cancer and supporting its role in precision oncology.

Predictive Value of Preoperative Maximum Standardized Uptake Value (SUVmax) in Patients with Advanced Gastric Cancer

Background: This study aimed to investigate the clinical and prognostic significance of preoperative maximum standardized uptake value (SUVmax) and GLUT-1 expression in patients with advanced gastric cancer (AGC). Methods: Medical records of patients who were diagnosed with AGC between 2018 and 2020 at Zhongshan Hospital of Fudan University (Shanghai, China) were retrospectively analyzed. Finally, 182 patients were enrolled, and for each patient, SUVmax was calculated for the primary lesion on PET/CT prior to curative surgery. A total of 165 clinical tissue specimens were collected for immunohistochemical analysis of GLUT-1 expression. Results: A total of 182 patients were divided into two groups based on their SUVmax values. The low SUVmax group comprised 92 patients. Patients with low SUVmax tended to be younger and included a higher proportion of women, with their primary tumors typically smaller or in earlier TNM stages. The median follow-up time was 52 months. The 1-, 3-, and 5-year progression-free survival (PFS) rates were 90.7%, 71.4%, and 67.0%, respectively. Among them, 33 patients experienced recurrence and metastasis, and 40 ultimately died. Log-rank analysis revealed that the low SUVmax group exhibited superior progression-free survival (PFS) and overall survival (OS). Multivariate analysis indicated that, for AGC without preoperative treatment, later stage (stage III) was independently correlated with a higher risk of recurrence (HR = 3.049; 95%CI = 1.076-8.639; p = 0.036), while the low SUVmax group exhibited a reduced risk of recurrence and mortality compared with the high SUVmax group (HR = 0.565; 95%CI = 0.326-0.979; p = 0.042). Conclusions: The clinicopathological characteristics of patients with AGC with different SUVmax values appeared significantly different. Tumor stage and SUVmax were found as independent factors affecting postoperative recurrence and death of patients with AGC.

The relationship between HER2 status acquired from pathological data and metabolic parameters from pre-treatment [18F]FDG PET/CT in gastric adenocarcinomas

OBJECTIVE

Overexpression of Human Epidermal Growth Factor Receptor 2 (HER2) is thought to be more aggressive in gastric cancer. This study aimed to evaluate the predictability of HER2 status and other prognostic pathologic parameters using [18F]FDG PET/CT and to investigate its impact on survival.

METHODS

Pretreatment metabolic parameters measured by [18F]FDG PET/CT as a prognostic factor were retrospectively evaluated in 117 HER2-analysed patients. The relationship between pathological data, tumor metabolic characteristics, and distant metastases was examined, and the effect on survival was investigated.

RESULTS

Among the 117 patients, 17.1% were HER2-positive (HER2+), and 82.9% were HER2-negative (HER2-). There was no significant association between PET/CT parameters in the HER2+ and HER2- patient groups. HER2+ patients had higher 1- and 3-year survival expectations than HER2- patients (80%-%37.9; %47.5-%20; respectively). There was no statistically significant difference in overall survival. In Cox-regression analysis, while the presence of vascular invasion, local invasion, and distant metastasis were poor prognostic factors, HER2 was not a prognostic factor. Vascular invasion and local invasion (T3/T4) were also associated with higher SUVmax values. Patients with distant metastases had significantly higher SUVmax, SUVmean, and TLG.

CONCLUSION

This study showed no association between HER2 expression and [18F]FDG PET/CT metabolic parameters. However, regardless of HER2 status, the results indicated distant metastasis, local invasion, and vascular invasion could be associated with primary tumor metabolism. PET/CT parameters predict tumor aggressiveness and disease prognosis better than HER2 status.

Evaluation of fluorine-18-fluorodeoxyglucose PET/computed tomography and human epithelial growth factor receptor 2 expression in treatment-naive patients with lung adenocarcinoma

OBJECTIVE

Human epithelial growth factor receptor 2 (HER2) is overexpressed in several types of cancers. The correlation between tumor glucose activity and HER2 expression can vary. This study is a retrospective investigation of fluorine-18-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) and HER2 expression status in patients with lung adenocarcinoma.

METHODS

The maximum standard uptake value (SUVmax) of 18F-FDG PET/CT was compared with the HER2 expression status in pretreated patients with lung adenocarcinoma. Moreover, clinicopathological characteristics, including age, gender, smoking, serum tumor markers, tumor location, size, stage and genetic mutation, were also evaluated in groups with different HER2 expressions. Patients' progression-free survival (PFS) and overall survival (OS) were also analyzed.

RESULTS

Ninety-six patients with HER2 expression, including 54 patients with HER2 overexpression and 30 patients without HER2 expression were enrolled in this study. The primary pulmonary lesion was single in all patients, and all lesions were FDG-avid on PET/CT. SUVmax had no significant association with HER2 expression or overexpression in lung adenocarcinoma. Moreover, elevated serum CYFRA211 levels were obviously associated with HER2 expression but not associated with HER2 overexpression. There were no significant differences in other clinicopathological characteristics in groups with different HER2 expressions. Furthermore, multivariate Cox regression analysis revealed that SUVmax, HER2 expression and tumor node metastasis stage were independent predictors of PFS, and SUVmax, CYFRA211 and epidermal growth factor receptor mutation were independent predictors of OS.

CONCLUSION

SUVmax had no significant association with the HER2 expression status in lung adenocarcinoma. 18F-FDG PET/CT and HER2 expression could provide valuable prognostic information for treatment-naive patients with lung adenocarcinoma.

The Relationship Between HER-2 Expression Levels and 18F-FDG PET/CT Parameters in Gastric Cancer

Objectives:

Human epidermal growth factor receptor-2 (HER-2) is a protooncogene encoded by ERBB2 on chromosome 17. ¹⁸Fluoridefluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) examination is frequently used to detect distant metastasis in gastric cancer imaging. This study aimed to investigate the relationship between the data obtained in the ¹⁸F-FDG PET/CT examination and HER-2 expression status in patients with gastric cancer.

Methods:

A total of 115 patients diagnosed with gastric cancer between 2016 and 2020, with HER-2 immunohistochemical followed by ¹⁸F-FDG PET/CT examination for staging purposes were included.

Results:

HER-2 immunohistochemical examination revealed 71 patients (61.7%) with negative and 44 (38.3%) with positive results. The median maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) values of patients positive with HER-2 were 9.95, 5, 30.44, and 139.16, respectively, whereas patients negative with HER-2 were 9.3,5.4,36.62, and 190.424, respectively (p>0.05). The median cancer antigen 19-9 (CA 19-9) levels of patients positive with HER-2 was 33.52, whereas 11.79 in those who were negative (p=0.016). The mean age was 69.3±9.35 years in patients with distant metastases, whereas 65.2±10.9 in those without distant metastases (p=0.042). Median SUV_max and SUV_mean values in patients with distant metastases were 11.1 and 6.3, respectively, and 8.2 and 4.5 in those without distant metastases (p=0.002 and p=0.001, respectively). The median CA 19-9 and carcinoembryonic antigen (CEA) levels in patients with distant metastases were 31.34 and 9.20, respectively, whereas those without distant metastases were 11.55 and 2.26, respectively (p=0.011 and p=0.001, respectively).

Conclusion:

In our study, no statistically significant difference was found in terms of HER-2 status, SUV_max, SUV_mean, MTV, TLG, distant metastasis, presence of lymph node metastasis, age, gender, tumor diameter, grade, and localization, and CEA levels in patients with gastric cancer. A statistically significant difference was found between HER-2 status and CA 19-9 levels. A statistically significant relationship was found between distant metastases in the ¹⁸F-FDG PET/CT examination and SUV_max, SUV_mean, age, CEA levels, and histopathologic diagnosis; however, the relationship between distant metastasis in the ¹⁸F-FDG PET/CT scan and MTV, TLG, tumor diameter, localization, and grade was not statistically significant.

The correlation between molecular pathological profiles and metabolic parameters of 18F-FDG PET/CT in patients with gastroesophageal junction cancer

OBJECTIVE

The aim of this study was to evaluate PET/FDG metabolic parameters in locally advanced GEJC and correlate it with molecular pathological profiles.

METHODS

We retrospectively analyzed data from 66 patients with a histopathological diagnosis of GEJC who had undergone ¹⁸F-FDG PET/CT before surgical resection. Maximum standardized uptake (SUV_max), mean standardized uptake (SUV_mean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured and calculated using the region of interest (ROI) technique. The relationship between metabolic parameters and the Lauren's classification, histologic differentiation, Ki-67 staining and positivity for human epidermal growth factor receptor 2 (HER2), c-Met, and epidermal growth factor receptor (EGFR) were investigated through immunohistochemical (IHC) analyses.

RESULTS

Of the total 66 patients, significant differences were observed between intestinal and non-intestinal (mixed and diffuse) adenocarcinomas in SUV_max (8.23 ± 2.83 vs. 6.29 ± 2.41, P = 0.008), SUV_mean (4.85 ± 1.47 vs. 3.93 ± 1.22, P = 0.017), MTV (24.96 cm³ vs. 8.90 cm³; P = 0.004), and TLG (97.38 cm³ vs. 37.09 cm³, P = 0.005) values. SUV_max, MTV, and TLG of moderately differentiated adenocarcinomas were significantly higher than those of the poorly differentiated ones. SUV_max was significantly higher in tissues with a higher Ki-67 index or in the c-MET-negative group (P = 0.045, P = 0.036). No significant correlation was found between metabolic parameters and the expression of HER2 or EGFR in GEJC.

CONCLUSION

¹⁸F-FDG PET/CT may be useful for predicting the molecular pathological profiles of GEJC and for determining appropriate therapeutic strategy.

A 18FDG PET/CT-based volume parameter is a predictor of overall survival in patients with local advanced gastric cancer

Objective

The present study investigated the prognosis value of preoperative fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with local advanced gastric cancer (LAGC).

Methods

In total, 144 patients [median age 63 (range: 48−80) years old] with LAGC underwent¹⁸F-FDG PET/CT prior to any treatment. The maximum standardized uptake values (SUV_max), mean standardized uptake values (SUV_mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were measured on PET/CT and correlated with clinicopathological features and survival.

Results

Significant differences in SUV_mean, SUV_max, MTV and TLG were found according to Lauren’s classification, histologic grade and T category (P<0.05). During the 26.5-month follow-up, 51 (35.4%) patients died and 70 (48.6%) exhibited disease progression. The optimal thresholds of MTV and TLG were 15.1 cm³ and 47.3 cm³, respectively. The 3-year progression-free survival (PFS) and overall survival (OS) for patients with high TLG values were 30% and 38% compared to 38% and 47% for low TLG values, respectively (P<0.05). Univariate and multifactor analyses demonstrated that lymph node metastasis and T stage were independent prognostic factors for PFS; T stage, histologic grade and TLG were independent prognostic factors for OS (P<0.05). Molecular markers had no relationship with patient’s outcomes.

Conclusions

Metabolic activity of primary gastric tumors from ¹⁸F-FDG PET/CT is a prognostic factor in patients with LAGC.

Radiomic signature of 18F fluorodeoxyglucose PET/CT for prediction of gastric cancer survival and chemotherapeutic benefits

We aimed to evaluate whether radiomic feature-based fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging signatures allow prediction of gastric cancer (GC) survival and chemotherapy benefits. Methods: A total of 214 GC patients (training (n = 132) or validation (n = 82) cohort) were subjected to radiomic feature extraction (80 features). Radiomic features of patients in the training cohort were subjected to a LASSO cox analysis to predict disease-free survival (DFS) and overall survival (OS) and were validated in the validation cohort. A radiomics nomogram with the radiomic signature incorporated was constructed to demonstrate the incremental value of the radiomic signature to the TNM staging system for individualized survival estimation, which was then assessed with respect to calibration, discrimination, and clinical usefulness. The performance was assessed with concordance index (C-index) and integrated Brier scores. Results: Significant differences were found between the high- and low-radiomic score (Rad-score) patients in 5-year DFS and OS in training and validation cohorts. Multivariate analysis revealed that the Rad-score was an independent prognostic factor. Incorporating the Rad-score into the radiomics-based nomogram resulted in better performance (C-index: DFS, 0.800; OS, 0.786; in the training cohort) than TNM staging system and clinicopathologic nomogram. Further analysis revealed that patients with higher Rad-scores were prone to benefit from chemotherapy. Conclusion: The newly developed radiomic signature was a powerful predictor of OS and DFS. Moreover, the radiomic signature could predict which patients could benefit from chemotherapy.