18F-fluorodeoxyglucose uptake in advanced gastric cancer correlates with histopathological subtypes and volume of tumor stroma

Comparison of the diagnostic value of [68Ga]Ga-FAP-2286 PET/CT and [18F]-FDG PET/CT imaging in different types of pleural and peritoneal metastatic tumors

OBJECTIVE

To compare the diagnostic value of [68Ga]Ga-FAP-2286 PET/CT and [18F]-FDG PET/CT imaging in different types of pleural/peritoneal metastatic tumors.

METHODS

A retrospective analysis was conducted on patients who underwent both [18F]-FDG and [68Ga]Ga-FAP-2286 PET/CT in our department between January 2022 and November 2024. The maximum standardized uptake value (SUVmax), peak SUV (SUVpeak), and tumor-to-background ratio (TBR) of pleural/peritoneal metastatic lesions were measured, and the results obtained from the two imaging modalities were compared.

RESULTS

A total of 92 patients suspected of having pleural/peritoneal metastases were included in the study. The [68Ga]Ga-FAP-2286 PET/CT showed higher SUVmax, SUVpeak, TBR, and sensitivity compared to [18F]-FDG PET/CT (7.87 vs. 6.28; P = 0.002; 5.88 vs. 4.65; P < 0.001; 6.27 vs. 3.85; P < 0.001; 95.3% vs. 84.7%; P = 0.035), especially for peritoneal metastases (8.25 vs. 5.75; P < 0.001; 6.18 vs. 4.29; P < 0.001; 6.54 vs. 3.50; P < 0.001). Among various tumors, [68Ga]Ga-FAP-2286 PET/CT showed better detection results for hepatobiliary and pancreatic tumors (7.88 vs. 6.02, 5.88 vs. 4.33, 6.15 vs. 3.67), gastrointestinal tumors (8.27 vs. 5.69, 6.28 vs. 4.30, 7.03 vs. 3.50), and adenocarcinomas (8.30 vs. 5.80, 6.17 vs. 4.30, 6.60 vs. 3.55).

CONCLUSION

For pleural/peritoneal metastases, [68Ga]Ga-FAP-2286 PET/CT has a higher detection rate compared to [18F]-FDG PET/CT, providing better diagnostic efficacy, particularly for peritoneal metastases. Among various tumors, [68Ga]Ga-FAP-2286 PET/CT has higher diagnostic value in hepatobiliary and pancreatic tumors, gastrointestinal tumors, and adenocarcinomas.

18F-FAPI-42 PET/CT and 18F-FDG PET/CT in Patients with Malignant Digestive System Neoplasms: A Head-to-Head Comparative Study

PURPOSE

Radionuclide-labeled fibroblast activation protein inhibitor (FAPI) is an emerging tumor tracer. We sought to assess the uptake and diagnostic performance of 18F-FAPI-42 PET/CT compared with simultaneous 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG) PET/CT in primary and metastatic lesions in patients with malignant digestive system neoplasms and to determine the potential clinical benefit.

PROCEDURES

Forty-two patients (men = 30, women = 12, mean age = 56.71 ± 13.26 years) who underwent 18F-FDG PET/CT and 18F-FAPI-42 PET/CT simultaneously for diagnosis, staging, and restaging were enrolled. Quantitative data, including standardized uptake value (SUV), tumor-to-liver ratio (TLR), and tumor-to-blood pool ratio (TBR), were analyzed. Two independent readers performed a visual assessment of lesion number and location on PET/CT images. Interobserver agreement between two examinations was calculated using Cohen's kappa (κ).

RESULTS

Primary tumor locations included the liver (n = 20), stomach (n = 9), pancreas (n = 5), and intestine (n = 10). More intense 18F-FAPI-42 uptake and higher tumor-to-background contrast were detected in most primary and metastatic lesions compared with 18F-FDG, contributing to improved diagnostic accuracy ranging from 95.24% to 100%. Moreover, additional lesions showing 18F-FAPI-42 uptake in primary, locoregional and distant metastatic lesions were visualized, especially in multiple liver and peritoneal metastases. Patient-based interobserver agreement varied from moderate to strong, with suboptimal outcomes observed in primary tumors (κ = 0.441, P = 0.01) and preferable results derived from metastatic liver and bone lesions (κ = 1 and 0.896, both P < 0.01). 18F-FAPI-42 PET/CT resulted in modified treatment strategies for 40.48% (17/42) of patients, while 18F-FDG PET/CT led to altered therapeutic regimens in only 4.8% (2/42) of patients.

CONCLUSIONS

In selected patients with malignant digestive system neoplasms, our study shows that 18F-FAPI-42 PET/CT is a promising alternative for assessing primary tumors and metastases and aiding staging, restaging, and decision-making, with higher uptake and better lesion visualization compared with 18F-FDG. Additionally, it may shed light into the treatment selection and response assessment for FAP-targeted therapy or immunotherapy.

Capecitabine enhances sensitivity to oxaliplatin in advanced gastric cancer and the effects on patients' FOXP1 and GGT levels

OBJECTIVE

To investigate the effect of capecitabine on the sensitivity of oxaliplatin and on the level of transcription factor forkhead box P1 (FOXP1) and gamma-glutamyl transpeptidase (GGT) in patients with intermediate and advanced gastric cancer.

METHODS

A total of 152 Patients with advanced gastric cancer who were continuously diagnosed and treated in our hospital were selected as the study objects. The general data were retrospectively analyzed. The patients in the control group received oxaliplatin, while the patients in the study group received capecitabine on the basis of the control group. The FOXP1 expression level was detected using immunohistochemistry. Serum levels of GGT were measured by chemiluminescence. Protein levels were detected by Western blot. The prognostic factors were analyzed by the COX regression model. The Kaplan-Meier survival curve was used to analyze the survival of gastric cancer.

RESULTS

The effective rates (complete response, partial response, and stability) of the study group and the control group were 94.74% and 76.32%, respectively. Compared with adjacent normal tissues, the expression level of FOXP1 in gastric cancer tissues was lower (P < 0.05). After treatment, the average expression level of FOXP1 in the gastric cancer tissue of the study group was higher than the control group (P < 0.05). Moreover, lower FOXP1 expression was associated with lower overall survival (OS) (1-year survival and 3-year survival were 75.76% and 53.03%, respectively) (P < 0.05). Further analysis showed that capecitabine combined with oxaliplatin down-regulated the expression of DNA repair related-proteins and up-regulated the expression of key molecules of the apoptosis pathway, thus enhancing the killing effect of oxaliplatin on gastric cancer cells (P < 0.05). Both the 1-year and 3-year survival rates of the study group were higher than that in the control group (P < 0.05). The 1-year survival rate of 152 patients with gastric cancer was 84.87% (129/152) and the 3-year survival rate was 63.17% (96/152). Age, tumor-node-metastasis (TNM) stage, lymph node metastasis, chemotherapy regimen, FOXP1, and GGT levels were important factors in determining OS.

CONCLUSION

Capecitabine effectively enhanced the sensitivity of intermediate and advanced gastric cancer to oxaliplatin, improved the therapeutic effect and ameliorated the prognosis of patients.

Impact of 68Ga-FAPI positron emission tomography/computed tomography on staging and tumor management in patients with gastric cancer

PURPOSE

To evaluate the added value of additional 68Ga-FAPI PET/CT following CT for primary staging, detection of postoperative recurrence, and management of gastric cancer patients.

METHODS

We retrospectively included patients with gastric cancers who underwent contrast-enhanced computed tomography (ceCT), followed by 68Ga-FAPI PET/CT within 30 days. 68Ga-FAPI PET/CT was performed for initial staging or detection of postoperative recurrence. Two nuclear medicine physicians and a radiologist independently decided on imaging-based staging. Pre-68Ga-FAPI PET/CT treatment decisions were made by a simulated tumor board and post-68Ga-FAPI PET/CT decisions were extracted from medical records. We evaluated the impact of 68Ga-FAPI PET/CT with inconsistent new findings based on the initial findings from ceCT and the resulting changes in treatment strategies.

RESULTS

We included 112 patients, 84 for initial staging and 28 for detection of postoperative recurrence. Compared to CT, 29 new findings in 24 patients were diagnosed as, or ruled out, cancer involvement on 68Ga-FAPI PET/CT. Among the 112 patients, 21 patients (18.8%) experienced changes in stage or postoperative recurrence. Among patients for initial staging, 14 had stage changes, with 10 being upstaged and 4 being downstaged. Among patients for detection of postoperative recurrence, 7 more patients were diagnosed with tumor recurrence. New findings of 68Ga-FAPI PET/CT led to treatment change in 20/112 (17.9%) patients, which was deemed of major change in 19 patients and minor change in 1 patient.

CONCLUSIONS

68Ga-FAPI PET/CT is valuable for precise staging and detection of postoperative recurrence of gastric cancers, and has the potential to influence management.

Capecitabine enhances sensitivity to oxaliplatin in advanced gastric cancer and the effects on patients' FOXP1 and GGT levels

Objective

To investigate the effect of capecitabine on the sensitivity of oxaliplatin and on the level of transcription factor forkhead box P1 (FOXP1) and gamma-glutamyl transpeptidase (GGT) in patients with intermediate and advanced gastric cancer.

Methods

A total of 152 patients with intermediate and advanced gastric cancer diagnosed and treated in our hospital from April 2018 to May 2019 was selected as the research objects, and their clinical data were retrospectively analyzed. According to the different treatment methods, they were divided into the study group and the control group, with 76 cases in each group. The patients in the control group received with oxaliplatin, while the patients in the study group received with capecitabine on the basis of the control group. The therapeutic effect was evaluated according to the therapeutic effect evaluation criteria of solid tumors. The FOXP1 expression level in gastric cancer tissues was detected using immunohistochemistry. Serum levels of GGT were measured by chemiluminescence. The prognostic factors were analyzed by COX regression model, and the Kaplan-Meier survival curve was used to analyze the relationship between the influencing factors and the survival of gastric cancer.

Results

The effective rate of capecitabine combined with oxaliplatin and oxaliplatin alone in the treatment of patients with intermediate and advanced gastric cancer were 94.74 % and 76.32 % respectively. Capecitabine enhanced the sensitivity of intermediate and advanced gastric cancer to oxaliplatin (P < 0.05). Compared with adjacent normal tissues, the expression level of FOXP1 in gastric cancer tissues was lower (P < 0.05). Before treatment, the expression of FOXP1 was low, and no significant difference was observed in the GGT level between the two groups (P > 0.05). After treatment, the low expression rate of FOXP1 and serum GGT level were both significantly decreased, and those in the study group were lower than those in the control group (P < 0.05). There was no difference in the incidence of adverse reactions between the two groups (P > 0.05). The 1-year survival rates of the study group and the control group were 90.79 % and 78.95 %, while the 3-year survival rates of the study group and the control group were 75.00 % and 51.32 %, respectively. Both the 1-year and 3-year survival rate of the study group was higher than that in the control group (P < 0.05). The 1-year survival rate of 152 patients with gastric cancer was 84.87 % (129/152) and the 3-year survival rate was 63.17 % (96/152). Age, tumor diameter, tumor-node-metastasis (TNM) stage, lymph node metastasis, chemotherapy regimen and the expression of FOXP1 and GGT had significant effects on the survival rate (P < 0.05). Gastric cancer patients with age <60 years, TNM stage of Ⅰ ∼ Ⅱ, lymph node metastasis N0 ∼ N1, high expression of FOXP1, GGT <387.2, and combined with drug chemotherapy had higher survival rate.

Conclusion

Capecitabine effectively enhanced the sensitivity of intermediate and advanced gastric cancer to oxaliplatin, improved the therapeutic effect, reduced the proportion of patients with low FOXP1 expression rate and serum GGT level, decreased the recurrence rate and ameliorated the prognosis of patients.

Patient metabolic profile defined by liver and muscle 18F-FDG PET avidity is independently associated with overall survival in gastric cancer

BACKGROUND

PET-CT-based patient metabolic profiling is a novel concept to incorporate patient-specific metabolism into gastric cancer care.

METHODS

Staging PET-CTs, demographics, and clinicopathologic variables of gastric cancer patients were obtained from a prospectively maintained institutional database. PET-CT avidity was measured in tumor, liver, spleen, four paired muscles, and two paired fat areas in each patient. The liver to rectus femoris (LRF) ratio was defined as the ratio of SUVmean of liver to the average SUVmean of the bilateral rectus femoris muscles. Kaplan-Meier and Cox-proportional hazards models were used to identify the impact of LRF ratio on OS.

RESULTS

Two hundred and one patients with distal gastroesophageal (48%) or gastric (52%) adenocarcinoma were included. Median age was 65 years, and 146 (73%) were male. On univariate analysis, rectus femoris PET-CT avidity and LRF ratio were significantly associated with overall survival (p < 0.05). LRF ratio was significantly higher in males, early-stage cancer, patients with an ECOG 0 or 1 performance status, patients with albumin > 3.5 mg/dL, and those with moderately differentiated tumor histology. In multivariable regression, gastric cancer stage, albumin, and LRF ratio were significant independent predictors of overall survival (LRF ratio HR = 0.73 (0.56-0.96); p = 0.024). Survival curves showed that the prognostic impact of LRF was associated with metastatic gastric cancer (p = 0.009).

CONCLUSIONS

Elevated LRF ratio, a patient-specific PET-CT-based metabolic parameter, was independently associated with an improvement in OS in patients with metastatic gastric cancer. With prospective validation, LRF ratio may be a useful, host-specific metabolic parameter for prognostication in gastric cancer.

Usefulness of [68Ga]FAPI-04 and [18F]FDG PET/CT for the detection of primary tumour and metastatic lesions in gastrointestinal carcinoma: a comparative study

OBJECTIVE

To assess and compare the diagnostic performance of gallium-68-labelled fibroblast activation protein inhibitor ([⁶⁸Ga]FAPI-04) and fluorine-18 fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) in gastrointestinal cancer.

METHODS

Fifty-one patients who underwent both [¹⁸F]FDG and [⁶⁸Ga]FAPI-04 PET/CT for initial staging or restaging were enrolled. Histopathological findings, typical radiological appearances, and clinical imaging follow-up were used as the reference standard. The diagnostic performance of the two tracers was calculated and compared. The maximum standardised uptake value (SUVmax), mean SUV (SUVmean), tumour-to-mediastinal blood pool ratio (TBR), and tumour-to-liver ratio (TLR) of primary and metastatic lesions were measured and compared between two imaging modalities.

RESULTS

In patient-based analysis, [⁶⁸Ga]FAPI-04 showed much better diagnostic sensitivity than [¹⁸F]FDG in detecting primary tumour (94.44% [17/18] vs. 61.11% [11/18]), postoperative recurrence and metastases (95.65% [22/23] vs. 69.57% [16/23]), and peritoneal carcinomatosis (100% [28/28] vs. 60.71% [17/28]) (all p < 0.05). In lesion-based analysis, [⁶⁸Ga]FAPI-04 showed higher sensitivity than [¹⁸F]FDG for detecting lymph node metastases. In peritoneal carcinomatosis, the median SUVmax (12.12 vs. 7.18) and SUVmean (6.84 vs. 4.11) with [⁶⁸Ga]FAPI-04 were significantly higher than those with [¹⁸F]FDG (all p < 0.005). The TBR and TLR of [⁶⁸Ga]FAPI-04 were significantly higher than those of [¹⁸F]FDG for detecting primary tumour, lymph node, liver, and peritoneal metastases (all p < 0.005). Therapeutic management changed in 13 patients according to [⁶⁸Ga]FAPI-04 PET/CT compared with conventional imaging.

CONCLUSIONS

[⁶⁸Ga]FAPI-04 is superior to [¹⁸F]FDG PET/CT for detecting primary tumour, postoperative recurrence and metastasis, and peritoneal carcinomatosis in gastrointestinal cancer.

KEY POINTS

• [⁶⁸Ga]FAPI-04 PET/CT showed significantly higher sensitivity than [¹⁸F]FDG PET/CT in the detection of primary tumour and postoperative recurrence and metastasis in patients with gastrointestinal carcinoma. • [⁶⁸Ga]FAPI-04 PET/CT had obvious advantages over [¹⁸F]FDG PET/CT in the detection of peritoneal carcinomatosis from gastrointestinal carcinoma with a much higher FAPI uptake value, TBR, and TLR. • Although the median SUVmax and SUVmean of [⁶⁸Ga]FAPI-04 were similar to those of [¹⁸F]FDG for the primary tumour, lymph node metastases, and liver metastases in gastrointestinal carcinoma, the TBR and TLR of the SUVmax and SUVmean were significantly higher on [⁶⁸Ga]FAPI-04 PET/CT, causing the lesions to be displayed more clearly.

Epigenetic modification facilitates proline synthase PYCR1 aberrant expression in gastric cancer

BACKGROUND & AIMS

Pyrroline-5-carboxylate reductase 1 (PYCR1) upregulation contributes to the progression of gastric cancer (GC) and indicates poor survival. However, PYCR1 expression profile in GC subtypes and the mechanism behind its upregulation are not well-studied.

METHODS

PYCR1 expression profiles in GC subtypes and different stages of gastric carcinogenesis were assessed in different GC cohorts. Genetic alterations and epigenetic modulation in PYCR1 regulation were further investigated using bioinformatics analysis and in vitro experiments.

RESULTS

PYCR1 expression was significantly higher in intestinal-type GC and associated molecular subtypes in TCGA and ACRG GC cohorts. During the cascade of intestinal-type GC, PYCR1 was continuously increased from normal gastric tissues through to atrophic gastritis, to intraepithelial neoplasia, and to GC. Copy number alterations in PYCR1 were associated with PYCR1 transcript expression. One CpG island was observed in PYCR1 promoter region, and the hypomethylation occurred at this region could contribute to PYCR1 transcriptional activation in GC. Besides, H3K27ac combination was found in PYCR1 promoter, and acetyltransferase p300 induced H3K27ac could promote PYCR1 expression in GC.

CONCLUSIONS

PYCR1 expression varies across GC subtypes, with intestinal-type GC and associated molecular subtypes having the highest expression. Hypomethylation at CpG sites and p300-induced H3K27ac modification within PYCR1 promoter could contribute to maintaining PYCR1 overexpression in GC. These results provide us with a new insight into epigenetic modulation in mitochondrial proline metabolism.