Expression of the DNA repair gene MLH1 correlates with survival in patients who have resected pancreatic cancer and have received adjuvant chemoradiation: NRG Oncology RTOG Study 9704

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.

Evaluation of biomarkers, genetic mutations, and epigenetic modifications in early diagnosis of pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is one of the deadliest malignancies with an alarming mortality rate. Despite significant advancement in diagnostics and therapeutics, early diagnosis remains elusive causing poor prognosis, marred by mutations and epigenetic modifications in key genes which contribute to disease progression.

AIM

To evaluate the various biological tumor markers collectively for early diagnosis which could act as prognostic biomarkers and helps in future therapeutics of PC in Kashmir valley.

METHODS

A total of 50 confirmed PC cases were included in the study to evaluate the levels of carbohydrate antigen 19-9 (CA 19-9), tissue polypeptide specific antigen (TPS), carcinoembryonic antigen (CEA), vascular endothelial growth factor-A (VEGF-A), and epidermal growth factor receptor (EGFR). Mutational analysis was performed to evaluate the mutations in Kirsten rat sarcoma (KRAS), Breast cancer type 2 (BRCA-2), and deleted in pancreatic cancer-4 (DPC-4) genes. However, epigenetic modifications (methylation of CpG islands) were performed in the promoter regions of cyclin-dependent kinase inhibitor 2A (p16; CDKN2A), MutL homolog 1 (hMLH1), and Ras association domain-containing protein 1(RASSF1A) genes.

RESULTS

We found significantly elevated levels of biological markers CA 19-9 (P ≤ 0.05), TPS (P ≤ 0.05), CEA (P ≤ 0.001), and VEGF (P ≤ 0.001). Molecular genetic analysis revealed that KRAS gene mutation is predominant in codon 12 (16 subjects, P ≤ 0.05), and 13 (12 subjects, P ≤ 0.05). However, we did not find a mutation in DPC-4 (1203G > T) and BRCA-2 (617delT) genes. Furthermore, epigenetic modification revealed that CpG methylation in 21 (P ≤ 0.05) and 4 subjects in the promoter regions of the p16 and hMLH1 gene, respectively.

CONCLUSION

In conclusion, CA 19-9, TPS, CEA, and VEGF levels were significantly elevated and collectively have potential as diagnostic and prognostic markers in PC. Global data of mutation in the KRAS gene commonly in codon 12 and rare in codon 13 could augment the predisposition towards PC. Additionally, methylation of the p16 gene could also modulate transcription of genes thereby increasing the predisposition and susceptibility towards PC.

Equipping the American Joint Committee on Cancer Staging for Resectable Pancreatic Ductal Adenocarcinoma with Tumor Grade: A Novel Staging System

Background

The 8th American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC) outperforms its previous version in reproducibility but not in survival discrimination. Tumor grade, an indicator of the aggressive biology of PDAC, has been suggested as a reliable prognostic factor. This study aimed to construct a novel staging system with greater prognostication for resectable PDAC by incorporating tumor grade into the 8th AJCC system.

Methods

A total of 9966 patients with resectable PDAC from the Surveillance Epidemiology and End Results (SEER) database were randomly separated into training and interval validation sets. Another 324 patients from our center were included as an external validation set. We proposed a novel staging system by sorting the substages yielded by a combination of T, N, and tumor grade based on their overall survival (OS) and grouping them into several stages. Prognostic homogeneity and discrimination were determined using the likelihood ratio χ ² and the linear trend χ ² test, respectively. Prognostic accuracies were evaluated by the area under the receiver operating characteristics curve (AUC).

Results

Using the 8th AJCC system, the prognosis of patients within the same stage was quite heterogeneous among different substages. The multivariate Cox model identified the tumor grade (hazard ratio 1.333, 95% confidence interval 1.250-1.423, p < 0.001) was an independent prognostic factor of the OS. In the training set, the AUC, homogeneity, and discriminatory ability were superior for the novel staging system than for the 8th AJCC system (0.642 vs. 0.615, 403.4 vs. 248.6, and 335.1 vs. 218.0, respectively). Similar results were observed in the internal and external validation sets.

Conclusions

The novel staging system incorporating tumor grade into the 8th AJCC system was associated with better prognostic accuracy, homogeneity, and discriminatory ability among resectable PDAC patients. Moreover, the novel staging system also allowed possibly adjuvant chemotherapy decisions.

Development and validation of a prognostic model to predict the prognosis of patients who underwent chemotherapy and resection of pancreatic adenocarcinoma: a large international population-based cohort study

BACKGROUND

Pancreatic cancer (PaC) remains extremely lethal worldwide even after resection. PaC resection rates are low, making prognostic studies in resected PaC difficult. This large international population-based study aimed at exploring factors associated with survival in patients with resected TNM stage I-II PaC receiving chemotherapy and at developing and internationally validating a survival-predicting model.

METHODS

Data of stage I-II PaC patients resected and receiving chemotherapy in 2003-2014 were obtained from the national cancer registries of Belgium, the Netherlands, Slovenia, and Norway, and the US Surveillance, Epidemiology, and End Results (SEER)-18 Program. Multivariable Cox proportional hazards models were constructed to investigate the associations of patient and tumor characteristics with overall survival, and analysis was performed in each country respectively without pooling. Prognostic factors remaining after backward selection in SEER-18 were used to build a nomogram, which was subjected to bootstrap internal validation and external validation using the European datasets.

RESULTS

A total of 11,837 resected PaC patients were analyzed, with median survival time of 18-23 months and 3-year survival rates of 21-31%. In the main analysis, patient age, tumor T stage, N stage, and differentiation were associated with survival across most countries, with country-specific association patterns and strengths. However, tumor location was mostly not significantly associated with survival. Resection margin, hospital type, tumor size, positive and harvested lymph node number, lymph node ratio, and comorbidity number were associated with survival in certain countries where the information was available. A median survival time- and 1-, 2-, 3-, and 5-year survival probability-predictive nomogram incorporating the backward-selected variables in the main analysis was established. It fits each European national cohort similarly well. Calibration curves showed very good agreement between nomogram-prediction and actual observation. The concordance index of the nomogram (0.60) was significantly higher than that of the T and N stage-based model (0.56) for predicting survival.

CONCLUSIONS

In these large international population-based cohorts, patients with resected PaC receiving chemotherapy have distinct characteristics independently associated with survival, with country-specific patterns and strengths. A robust benchmark population-based survival-predicting model is established and internationally validated. Like previous models predicting survival in resected PaC, our nomogram performs modestly.

Adjuvant therapeutic strategies for resectable pancreatic adenocarcinoma

Of all patients diagnosed with pancreatic adenocarcinoma, only 15-20% present with resectable disease. Despite curative-intent resection, the prognosis remains poor with the majority of patients recurring, prompting the need for adjuvant therapy. Historical data support the use of adjuvant 5-fluorouracil (5-FU) or gemcitabine, but recent data suggest either gemcitabine plus capecitabine or modified FOLFIRINOX can improve overall survival when compared to gemcitabine alone. The use of adjuvant chemoradiation therapy remains controversial, primarily due to limitations in study design and mixed results of historical trials. The ongoing Radiation Therapy Oncology Group (RTOG)-0848 trial hopes to further define the role of adjuvant chemoradiation therapy. Intraoperative radiation therapy (IORT) and adjuvant immunotherapy represent additional possibilities to improve outcomes, but evidence supporting their use is limited. This article reviews adjuvant therapeutic strategies for resectable pancreatic adenocarcinoma, including chemotherapy, chemoradiation therapy, IORT and immunotherapy.