Prognostic Factors and Effect of Adjuvant Chemoradiation Following Chemotherapy in Resected Pancreatic Cancer Patients With Lymph Node Metastasis or R1 Resection

Comparing the clinical value of baseline [68 Ga]Ga-FAPI-04 PET/CT and [18F]F-FDG PET/CT in pancreatic ductal adenocarcinoma: additional prognostic value of the distal pancreatitis

PURPOSE

Anatomical and molecular staging strategies are needed for the personalized treatment of localized pancreatic ductal adenocarcinoma (PDAC). This study evaluated the performance of [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT on the disease staging and prognostic value of patients with localized PDAC on contrast-enhanced (CE)-CT images.

METHODS

Patients with suspected localized PDAC on CE-CT were recruited for static [68 Ga]Ga-FAPI-04 and 18[F]F-FDG and PET/CT, and select patients underwent simultaneous 60-min dynamic 68 Ga-FAPI-04 PET/CT. The diagnostic and staging performances of the static PET/CT results were evaluated by delineating regions of interest in the primary tumor, whole pancreas, and distal pancreas in both types of scans and then evaluating correlations between the PET/CT findings and clinicopathological characteristics. Furthermore, Kaplan-Meier and hazard ratio (log-rank) methods were used to evaluate the prognostic value of the combined dynamic [68 Ga]Ga-FAPI-04 and static [18F]F-FDG PET/CT method.

RESULTS

We included 49 patients with histologically confirmed PDAC adenocarcinomas; 32 underwent 60-min dynamic [68 Ga]Ga-FAPI-04 PET/CT imaging simultaneously. The static [68 Ga]Ga-FAPI-04 method had significantly higher accuracy and uptake values than the static [18F]F-FDG method for primary PDAC lesions, metastatic lymph nodes, and distal metastases. Furthermore, 18.4% and 10.2% of the patients' stages changed after using the [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT methodologies, respectively, compared to the CE-CT-designated stage. The Ki values obtained from dynamic [68 Ga]Ga-FAPI-04 PET/CT did not differ between PDAC and distal obstructive pancreatitis lesions. Pathologically enlarged tumor size, poor differentiation, and perineural invasion were associated with increased [68 Ga]Ga-FAPI-04 uptake but not with [18F]F-FDG uptake. The preoperative prognostic performance of [68 Ga]Ga-FAPI-04 was better than that of [18F]F-FDG. Interestingly, combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG uptake results in the whole pancreas could further stratify patients based on their postoperative prognosis.

CONCLUSION

6[68 Ga]Ga-FAPI-04 PET/CT was more sensitive and accurate than [18F]F-FDG PET/CT for tumor, node, and metastasis staging of PDAC identified on CE-CT. Additionally, [68 Ga]Ga-FAPI-04 uptake was significantly associated with pathologically aggressive tumor features. Combined [68 Ga]Ga-FAPI-04 and [18F]F-FDG PET/CT findings improved the prognostic value, potentially providing a non-invasive guide for clinical management. Finally, increased fibroblast activity in PDAC-induced obstructive pancreatitis may be associated with poor patient survival rates.

Additional adjuvant radiotherapy improves survival at 1 year after surgical treatment for pancreatic cancer patients with T4, N2 disease, positive resection margin, and receiving adjuvant chemotherapy

Background

While adjuvant chemotherapy has been established as standard practice following radical resection of pancreatic ductal adenocarcinoma (PDAC), the role of adjuvant radiation therapy (RT) and which patients may benefit remains unclear.

Methods

This retrospective study included PDAC patients who received pancreatic surgery from April 2012 to December 2019 in Zhongshan Hospital Fudan University. Patients with carcinoma in situ, distant metastasis, and without adjuvant chemotherapy were excluded. Cox proportional hazards modeling of survival were constructed to find potential prognostic factors. Propensity score matching (PSM) and exploratory subgroup analyses were used to create a balanced covariate distribution between groups and to investigate therapeutic effect of radiotherapy in certain subgroups.

Results

A total of 399 patients were finally included, 93 of them receiving adjuvant chemoradiotherapy (C+R+) and 306 of them receiving chemotherapy only. Patients in C+R+ group were more likely to be male patients with T3-4 disease. Lymph node metastases was the only negative prognostic factor associated with overall survival (OS). Additional adjuvant RT was not associated with an OS benefit both before and after PSM. Surprisingly, a trend towards improved OS with RT among patients with either T4, N2 disease or R1 resection becomes significant in patients alive more than 1 year after surgery.

Conclusion

Adjuvant RT was not associated with an OS benefit across all patients, though did show a possible OS benefit for the subgroup with T4N2 disease or R1 resection at 1 year after surgery.

Comparison of adjuvant gemcitabine plus S-1 with S-1 monotherapy for pancreatic ductal adenocarcinoma: Retrospective real-world data

BACKGROUND

S-1 has been recognized as one of the standard adjuvant chemotherapies for pancreatic ductal adenocarcinoma (PDAC) in East Asia, but the optimal adjuvant chemotherapy regimen has not been determined. We aimed to compare the efficacy and safety of adjuvant gemcitabine plus S-1 (GS) with S-1 monotherapy for PDAC.

METHODS

Patients with resected PDAC who received adjuvant GS or S-1 chemotherapy in Peking Union Medical College Hospital between May 2014 and May 2022 were reviewed. Data retrieved from medical records were used to evaluate efficacy and toxicity.

RESULTS

A total of 241 patients were included, with 167 receiving GS and 74 receiving S-1. The patients who received GS were generally younger (median [range] age: 62 [36-78] versus 64 [44-87] years, p = 0.004), but chemotherapy began later (median [range] interval between chemotherapy and surgery: 49 [17-125] versus 40 [16-100] days, p < 0.001). The median disease-free survival (DFS, 15.1 versus 15.9 months, p = 0.52) and overall survival (OS, 34.8 versus 27.1 months, p = 0.34) did not differ significantly between the GS and S-1 groups, even after adjustment for the biases. However, the chemotherapy completion rate was higher in the patients treated with S-1 (52.4% versus 75.7%, p = 0.006), while grade 3-4 neutropenia occurred more frequently in the GS group (49.5% versus 18.2%, p = 0.015).

CONCLUSIONS

Adjuvant S-1 monotherapy demonstrated noninferiority to the GS regimen in DFS and OS with better tolerability for PDAC following surgery.