Validation of genome-wide association study-identified single nucleotide polymorphisms in a case-control study of pancreatic cancer from Taiwan

Unraveling the clinical impact of differential DNA methylation in PDAC: A systematic review

INTRODUCTION

Despite significant efforts to improve clinical outcomes, pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate. The poor prognosis associated with this disease is multifactorial and associated with a highly variable genetic profile associated with its pathogenesis. Epigenetic modifications including DNA methylation further affect the expression of genetic material. However, there is no comprehensive understanding of the clinical impact of DNA methylation in PDAC.

METHODS

A systematic literature review was registered on the International Prospective Register of Systematic Reviews database (CRD42023451955) and followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. An electronic search was conducted using the following databases: CINAHL Plus, Cochrane Library, Embase, Web of Science, Ovid Medline, and Google Scholar. Inclusion criteria included studies of patients with a PDAC diagnosis and information regarding genes or CpG sites that potentially affect diagnosis, prognosis, or survival of PDAC.

RESULTS

The initial search retrieved 2402 articles, and 423 duplicates were excluded. After exclusion criteria was applied, 19 studies were included. The most common genes recorded as affecting tumor pathogenesis were SFRP1 (n = 3/19, 15.7 %) and NPTX2 (n = 2/19, 10,5 %). Studies indicated that hypermethylation of SFRP1 and NPTX2 were associated with poor prognosis.

CONCLUSIONS

PDAC is associated with a range of epigenetic modifications. Methylation of specific genes related to PDAC may influence survival and prognosis and be a therapeutic target. Individual patient epigenetic analysis may be a future direction in directing PDAC treatment and prognosis.

Germline mutations of homologous recombination genes and clinical outcomes in pancreatic cancer: a multicenter study in Taiwan

BACKGROUND

Cancer susceptibility germline mutations are associated with pancreatic ductal adenocarcinoma (PDAC). However, the hereditary status of PDAC and its impact on survival is largely unknown in the Asian population.

METHODS

Exome sequencing was performed on 527 blood samples from PDAC individuals and analyzed for mutations in 80 oncogenic genes. Pathogenic and likely pathogenic (P/LP) germline variants were diagnosed according to the ACMG variant classification categories. The association between germline homologous recombination gene mutations (gHRmut, including BAP1, BRCA1, BRCA2, PALB2, ATM, BLM, BRIP1, CHEK2, NBN, MUTYH, FANCA and FANCC) and the treatment outcomes was explored in patients with stage III/IV diseases treated with first-line (1L) platinum-based versus platinum-free chemotherapy.

RESULTS

Overall, 104 of 527 (19.7%) patients carried germline P/LP variants. The most common mutated genes were BRCA2 (3.60%), followed by ATR (2.66%) and ATM (1.9%). After a median follow-up duration of 38.3-months (95% confidence interval, 95% CI 35.0-43.7), the median overall survival (OS) was not significantly different among patients with gHRmut, non-HR germline mutations, or no mutation (P = 0.43). Among the 320 patients with stage III/IV disease who received 1L combination chemotherapy, 32 (10%) had gHRmut. Of them, patients receiving 1L platinum-based chemotherapy exhibited a significantly longer median OS compared to those with platinum-free chemotherapy, 26.1 months (95% CI 12.7-33.7) versus 9.6 months (95% CI 5.9-17.6), P = 0.001. However, the median OS of patients without gHRmut was 14.5 months (95% CI 13.2-16.9) and 12.6 months (95% CI 10.8-14.7) for patients receiving 1L platinum-based and platinum-free chemotherapy, respectively (P = 0.22). These results were consistent after adjusting for potential confounding factors including age, tumor stage, performance status, and baseline CA 19.9 in the multivariate Cox regression analysis.

CONCLUSIONS

Our study showed that nearly 20% of Taiwanese PDAC patients carried germline P/LP variants. The longer survival observed in gHRmut patients treated with 1L platinum-based chemotherapy highlights the importance of germline testing for all patients with advanced PDAC at diagnosis.

Cancer-cell-derived cell-free DNA can predict distant metastasis earlier in pancreatic cancer: a prospective cohort study

Background:

Carbohydrate antigen 19-9 (CA19-9) is the only biomarker for monitoring responses during treatments of pancreatic cancer, but its accuracy for disease outcome is controversial. Fluid biopsy is a new method for diagnosis and monitoring treatment response. In this study, we investigate the usefulness of cell-free DNA (cfDNA) in predicting disease progression during the treatment of pancreatic cancer.

Methods:

Biopsy-proved advanced pancreatic cancer patients who received systemic chemotherapy were enrolled after signed informed consent. CA19-9 and cfDNA in blood were measured before and after every two cycles of treatments, and the disease progression was monitored by computed tomography (CT) with 3-month interval.

Results:

In total, 74 patients and 148 blood samples were enrolled in this study. Patients whose average blood cfDNA concentration of >9.71 ng/mL before and after first two courses of chemotherapy would subsequently show new distant metastasis (NDM) on CT scans 3 months later. The accuracy was 94.37% (AUC 0.9705, p < 0.0001) and the progression-free survival (PFS) and overall survival (OS) of patients with cfDNA concentration of >9.71 ng/mL were worse than those patients with cfDNA concentration of <9.71 ng/mL (median PFS: 95 days versus 322 days, p < 0.0001; median OS: 150 days versus 431 days, p < 0.0001). The cfDNA concentration of >9.71 ng/mL is a predictor for PFS, OS, and distant metastasis-free survival by multivariate analysis. Comparison of KRAS G12 variants detected by next-generation sequencing from tumor tissue issue and remnant DNA of cfDNA showed that increased cfDNA was primarily derived from cancer cells.

Conclusion:

The cancer-cell-derived cfDNA levels could be served as a powerful biomarker for prediction of NDM in patients with advanced/metastatic pancreatic cancer.

A phase II randomised trial of induction chemotherapy followed by concurrent chemoradiotherapy in locally advanced pancreatic cancer: the Taiwan Cooperative Oncology Group T2212 study

BACKGROUND

The objective of this study was to evaluate the efficacy and safety of induction chemotherapy (ICT), GOFL (gemcitabine, oxaliplatin plus fluorouracil (5-FU)/leucovorin) versus modified FOLFIRINOX (irinotecan, oxaliplatin plus 5-FU/leucovorin), followed by concurrent chemoradiotherapy (CCRT) in locally advanced pancreatic adenocarcinoma (LAPC).

METHODS

Chemo-naive patients with measurable LAPC were eligible and randomly assigned to receive biweekly ICT with either mFOLFIRINOX or GOFL for 3 months. Patients without systemic progression would have 5-FU- or gemcitabine-based CCRT (5040 cGy/28 fractions) and were then subjected to surgery or continuation of chemotherapy until treatment failure. The primary endpoint was 9-month progression-free survival (PFS) rate.

RESULTS

Between July 2013 and January 2019, 55 patients were enrolled. After ICT, 21 (77.8%) of 27 patients who received mFOLFIRINOX and 17 (60.7%) of 28 patients who received GOFL completed CCRT. Of them, one and five had per-protocol R0/R1 resection. On intent-to-treat analysis, the 9-month PFS rate, median PFS and overall survival in mFOLFIRINOX and GOFL arms were 30.5% versus 35.9%, 6.6 (95% confidence interval: 5.9-12.5) versus 7.6 months (3.9-12.3) and 19.6 (13.4-22.9) versus 17.9 months (13.4-23.9), respectively. Grade 3-4 neutropenia and diarrhoea during induction mFOLFIRINOX and GOFL were 37.0% versus 21.4% and 14.8% versus 3.6%, respectively.

CONCLUSION

Induction GOFL and mFOLFIRINOX followed by CCRT provided similar clinical outcomes in LAPC patients.

CLINICALTRIAL

GOV IDENTIFIER

NCT01867892.

Susceptibility loci for pancreatic cancer in the Brazilian population

BACKGROUND

Pancreatic adenocarcinoma (PA) is a very aggressive cancer and has one of the poorest prognoses. Usually, the diagnosis is late and resistant to conventional treatment. Environmental and genetic factors contribute to the etiology, such as tobacco and alcohol consumption, chronic pancreatitis, diabetes and obesity. Somatic mutation in pancreatic cancer cells are known and SNP profile by GWAS could access novel genetic risk factors for this disease in different population context. Here we describe a SNP panel for Brazilian pancreatic cancer, together with clinical and epidemiological data.

METHODS

78 pancreatic adenocarcinoma and 256 non-pancreatic cancer subjects had 25 SNPs genotyped by real-time PCR. Unconditional logistic regression methods were used to assess the main effects on PA risk, using allelic, co-dominant and dominant inheritance models.

RESULTS

9 SNPs were nominally associated with pancreatic adenocarcinoma risk, with 5 of the minor alleles conferring protective effect while 4 related as risk factor. In epidemiological and clinical data, tobacco smoking, diabetes and pancreatitis history were significantly related to pancreatic adenocarcinoma risk. Polygenic risk scores computed using the SNPs in the study showed strong associations with PA risk.

CONCLUSION

We could assess for the first time some SNPs related with PA in Brazilian populations, a result that could be used for genetic screening in risk population such as familial pancreatic cancer, smokers, alcohol users and diabetes patients.