Geographic and Ethnic Heterogeneity of Germline BRCA1 or BRCA2 Mutation Prevalence Among Patients With Metastatic Pancreatic Cancer Screened for Entry Into the POLO Trial

Germline pathogenic variants of cancer predisposition genes in a multicentre Italian cohort of pancreatic cancer patients

BACKGROUND AND AIM

Germline BRCA1-2 test is routinely recommended in Pancreatic Cancer (PC) patients, due to its clinical-epidemiological relevance. Data on the prevalence of germline pathogenic variants (gPV) in other cancer predisposition and DNA Damage Repair (DDR) system-related genes in unselected PC cases are sparce in Italy. We assessed this prevalence in a multicentre cohort, to derive recommendations for PC patients.

METHODS

Clinical data of 1200 consecutive PC patients, of any age and stage, tested with a multigene germline panel were collected. A descriptive analysis of gPV frequency and clinical variables was performed both in 1092 patients tested for an 18 genes core-panel (CP-18 cohort) and in 869 patients screened only for CDKN2A.

RESULTS

11.5 % (126/1092) of CP-18 cohort patients harbored a gPV in ≥ 1 gene. Highest gPV frequencies were detected in ATM (3.1 %), BRCA2 (2.9 %), BRCA1 (1.6 %), CHEK2 (1.1 %). Patients harboring any CP-18 gene and BRCA1-2 gPV were younger and with a higher rate of personal (PH) or family history (FH) of cancer when compared to no gPV patients. The risk of having a gPV was ≥ 7 % in all subgroups of patients, including those aged > 73, with tumor stage I-III and negative FH/PH. CDKN2A gPV were detected in 2.6 % (23/869) of patients.

CONCLUSIONS

A remarkable prevalence of gPV in cancer predisposition and DDR genes is reported in this large multicentre cohort of consecutive and unselected PC patients. Therefore, we recommend multigene germline testing (at least including BRCA1-2, ATM, CDKN2A, PALB2) for all PC patients, irrespective of age, stage, PH/FH.

Advances in Systemic Therapy in Pancreatic Cancer

Substantial progress has been made toward understanding biology and developing new therapies for pancreatic ductal adenocarcinoma (PDAC). In this review, new insights from genomic profiling, as well as implications for treatment and prognosis, are discussed. New standards of care approaches with a focus on drug therapies are discussed for the treatment of resectable and advanced PDAC. The role of targeted and immune therapies remains limited; cohorts likely to benefit from these approaches are discussed. Promising, preliminary results regarding experimental therapies are reviewed.

Molecular Characterization and Therapeutic Opportunities in KRAS Wildtype Pancreatic Ductal Adenocarcinoma

PURPOSE

To investigate the molecular characteristics of and potential for precision medicine in KRAS wildtype pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

We investigated 27 patients with KRASWT PDAC at our institution. Clinical data were obtained via chart review. Tumor specimens for each subject were interrogated for somatic single nucleotide variants, insertion and deletions, and copy number variants by DNA sequencing. Gene fusions were detected from RNA-seq. A patient-derived organoid (PDO) was developed from a patient with a MET translocation and expanded ex vivo to predict therapeutic sensitivity prior to enrollment in a phase 2 clinical trial.

RESULTS

Transcriptomic analysis showed our cohort may be stratified by the relative gene expression of the KRAS signaling cascade. The PDO derived from our patient harboring a TFG-MET rearrangement was found to have in vitro sensitivity to the multi-tyrosine kinase inhibitor crizotinib. The patient was enrolled in the phase 2 SPARTA clinical trial and received monotherapy with vebrelitinib, a c-MET inhibitor, and achieved a partial and durable response.

CONCLUSIONS

KRASWT PDAC is molecularly distinct from KRASMUT and enriched with potentially actionable genetic variants. In our study, transcriptomic profiling revealed that the KRAS signaling cascade may play a key role in KRASWT PDAC. Our report of a KRASWT PDAC patient with TFG-MET rearrangement who responded to a cMET inhibitor further supports the pursuit of precision oncology in this sub-population. Identification of targetable mutations, perhaps through approaches like RNA-seq, can help enable precision-driven approaches to select optimal treatment based on tumor characteristics.

The Use of Glucagon-like Peptide-1 Receptor Agonists in Patients with Type 2 Diabetes Mellitus Does Not Increase the Risk of Pancreatic Cancer: A U.S.-Based Cohort Study

BACKGROUND

GLP-1 RAs are widely used for T2DM treatment due to their cardiorenal and metabolic benefits. This study examines the risk of pancreatic cancer with GLP-1 RA use in patients with T2DM.

METHODS

We analyzed TriNetX's deidentified research database using the U.S. Collaborative Network comprising 62 healthcare organizations across the U.S.A. Patients with T2DM were split into two cohorts: one receiving GLP-1 RAs, and one not receiving GLP-1 RAs. We excluded patients with known risk factors for pancreatic cancer, including pancreatic cysts, a personal or family history of BRCA1, BRCA2, CDKN2A, KRAS, MEN1, MLH1, MSH2, NOTCH1, PALB2, PMS2, and PRSS1S genes, family history of pancreatic cancer, and VHL syndrome. Using a 1:1 propensity score-matching model based on baseline characteristics and comorbidities, we created comparable cohorts. We then compared the rate of pancreatic cancer between the two cohorts at a 7-year interval.

RESULTS

Out of 7,146,015 identified patients with T2DM, 10.3% were on a GLP-1 RA and 89.7% were not. Post-PSM, 721,110 patients were in each group. Patients on GLP-1 RAs had a 0.1% risk compared to a 0.2% risk of pancreatic cancer in the 7-year timeframe.

CONCLUSION

The use of GLP-1 RAs in patients with type 2 diabetes mellitus (T2DM) does not appear to substantially elevate the risk of pancreatic cancer; in fact, it may potentially exert a protective effect.

Integration of liposomal irinotecan in the first-line treatment of metastatic pancreatic cancer: try to do not think about the white bear

The approval of novel therapeutic agents remains widely reliant on evidence derived from large phase III randomized controlled trials. Liposomal irinotecan (ONIVYDE®) stands out as the only drug that has demonstrated improved survival both as a first-line therapy in combination with oxaliplatin and 5-fluorouracil/leucovorin (5FU/LV) (NALIRIFOX) compared to the standard gemcitabine plus nab-paclitaxel in the NAPOLI3 trial, and as a second-line treatment in combination with 5FU/LV compared to the standard 5FU/LV in the NAPOLI1 trial. However, just as the white bear of the Dostoevsky's paradox, the judgment of these results is invariably distracted by the intrusive thought of how different they might be if compared to similar regimens containing standard-free irinotecan as FOLFIRINOX or FOLFIRI, respectively. Here, we present and thoroughly discuss the evidence encompassing the pharmacologic, preclinical, and clinical development of liposomal irinotecan that can dispel any intrusive thoughts and foster a rational and well-considered judgment of this agent and its potential integration into the therapeutic strategies for pancreatic ductal adenocarcinoma.

Modeling health outcomes associated with BRCA testing and treatment strategies for patients with metastatic pancreatic cancer

BACKGROUND

Germline BRCA mutations (gBRCAm) occur in 4%-8% patients with metastatic pancreatic cancer (mPC); guidelines recommend platinum-based chemotherapies and olaparib maintenance in this population. We evaluated, through modeling, the role of treatments and gBRCA testing on health outcomes of mPC patients.

METHODS

A decision tree/partitioned survival model was developed to assess lifetime health outcomes for four strategies: 1) no testing; 2) early testing/no olaparib maintenance; 3) early testing (i.e., before 1L treatment)/olaparib maintenance; and 4) late testing/olaparib maintenance. Treatment patterns were assumed to follow current practice in the United States. Overall survival and progression-free survival curves were extrapolated from pivotal trials, including POLO trial for outcomes from olaparib maintenance after at least 16 weeks of platinum-based chemotherapy.

RESULTS

Among patients with gBRCAm, almost twice as many patients received platinum-based regimens in strategies involving early testing compared to when early testing was not employed (78.7 % vs 40.2 %). Health outcomes were highest in the strategy with early testing and available olaparib treatment whether considering progression-free life years (PF LYs, 1.27 vs 0.55-0.87), LYs (1.82 vs 0.95-1.27) or quality adjusted life years (QALYs, 1.15 vs 0.73-0.92 for others). Consistent patterns of results were observed in the overall cohort of mPC patients (i.e., irrespective of gBRCAm).

CONCLUSION

Patients with mPC achieved longest health outcomes (as measured by mean PF LYs, LYs and QALYs) with a scenario of early gBRCA testing and availability of olaparib maintenance. The results were primarily driven by improved health outcomes associated with higher efficacy of platinum-based chemotherapies and olaparib used in gBRCAm patients.

Understanding the Genetic Landscape of Pancreatic Ductal Adenocarcinoma to Support Personalized Medicine: A Systematic Review

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies worldwide. While population-wide screening recommendations for PDAC in asymptomatic individuals are not achievable due to its relatively low incidence, pancreatic cancer surveillance programs are recommended for patients with germline causative variants in PDAC susceptibility genes or a strong family history. In this study, we sought to determine the prevalence and significance of germline alterations in major genes (ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, TP53) involved in PDAC susceptibility. We performed a systematic review of PubMed publications reporting germline variants identified in these genes in PDAC patients. Overall, the retrieved articles included 1493 PDAC patients. A high proportion of these patients (n = 1225/1493, 82%) were found to harbor alterations in genes (ATM, BRCA1, BRCA2, PALB2) involved in the homologous recombination repair (HRR) pathway. Specifically, the remaining PDAC patients were reported to carry alterations in genes playing a role in other cancer pathways (CDKN2A, STK11, TP53; n = 181/1493, 12.1%) or in the mismatch repair (MMR) pathway (MLH1, MSH2, MSH6, PMS2; n = 87/1493, 5.8%). Our findings highlight the importance of germline genetic characterization in PDAC patients for better personalized targeted therapies, clinical management, and surveillance.

Health Disparities in Presentation, Treatment, Genomic Testing, and Outcomes of Pancreatic Cancer in Hispanic and Non-Hispanic Patients

BACKGROUND

There are few conflicting results regarding the treatment and outcomes of Hispanic patients with pancreatic cancer. This study comprehensively evaluated the differences in baseline characteristics, treatments, genomic testing, and outcomes among Hispanic (H) and Non-Hispanic (NH) patients with early-stage (ES) and late-stage (LS) pancreatic cancer (PC).

METHODS

This is a retrospective analysis from 2013 to 2020 of 294 patients with pancreatic ductal adenocarcinoma; data collected included patient demographics, clinical characteristics, treatment regimens, response, germline and somatic genetic testing, and survival outcomes. Excluded those with insufficient data. Univariate comparisons used parametric and nonparametric tests as appropriate to evaluate for differences between H and NH groups. Fisher's exact tests were performed to evaluate the difference in frequency. Kaplan-Meier and Cox regression analysis assessed the survival.

RESULTS

The analysis included 198 patients who had a late-stage disease and 96 patients with early-stage disease at the time of diagnosis. Among the early-stage patients, the median age at diagnosis was 60.7 years in the H versus 66.7 years in the NH (p = 0.03). No other differences were observed in baseline characteristics, treatments offered, and median overall survival (NH 25 vs. H 17.7 months, p = 0.28). Performance status, negative surgical margins, and adjuvant therapy were clinically significant and univariable with improved OS (p < 0.05), regardless of ethnicity. Hispanic patients with early pancreatic cancer were noted to be at a greater risk of death with a statistically significant hazard ratio of 3.1 (p = 0.005, 95% CI, 1.39-6.90). Among the late-stage patients, Hispanic patients with ≥ 3 predisposing risk factors for pancreatic cancer were 44% vs. 25% of NH (p = 0.006). No significant differences were noted in baseline characteristic treatments, progression-free, and median overall survivals (NH 10.0 vs. 9.2 months, p = 0.4577). In the late-stage genomic testing, germline testing performed in NH 69.4% vs. H 43.9% (p = 0.003) revealed no difference among groups. For the somatic testing, the pathogenic variants with actionable mutations were 2.5% of NH and 17.6% of H patients (p = 0.03).

CONCLUSION

Hispanic patients with early-stage pancreatic adenocarcinoma present at a younger age and with more risk factors in the late stage. These patients have significantly lower overall survival compared to their non-Hispanic counterparts. Hispanic patients in our study were 2.9 less likely to receive germline screening and more like to have somatic genetic actionable pathogenic variants. Overall, only a minority of all patients were enrolled in a pancreatic cancer clinical trial or offered genomic testing, highlighting a critical need and missed opportunity in advancing progress and improving outcomes for this disease, mainly in the underrepresented Hispanic population.

Clinical outcomes and response to chemotherapy in a cohort of pancreatic cancer patients with germline variants of unknown significance (VUS) in BRCA1 and BRCA2 genes

PURPOSE

The clinical outcome and the efficacy of chemotherapy in pancreatic cancer patients with BRCA1/2 Variants of Unknown Significance (VUS) is unknown. We explored the effects of chemotherapy with or without Platinum in non metastatic and metastatic pancreatic cancer patients with BRCA1/2 VUS.

METHODS

A retrospective analysis of non-metastatic or metastatic pancreatic cancer patients with gBRCA1/2 VUS treated in 13 Italian centers between November 2015 and December 2020 was performed. All patients were assessed for toxicity and RECIST 1.1 response. Metastatic patients were evaluated for survival outcome.

RESULTS

30 pancreatic cancer patients with gBRCA1/2 VUS were considered: 20 were M+ and 10 were non-M+. Pl-CT was recommended to 16 patients: 10 M+ (6 FOLFIRINOX and 4 PAXG) and 6 non-M+ (3 FOLFIRINOX and 3 PAXG); 11 patients received Nabpaclitaxel-Gemcitabine (AG; 8 M+) and 3 patients (2 M+) were treated with Gemcitabine (G). The RECIST 1.1 response rate was 27% for AG and 44% for Pl-CT (22% for (m) FOLFIRINOX and 71% PAXG). 1 year Progression-Free Survival was 37.5% for patients treated with AG and 33% in the Pl-CT subgroup. Median Overall Survival (OS) was 23.5 months for patients treated with AG and 14 months for the Pl-CT subgroup. 1 Year and 2 Year OS were numerically better for AG (1 Year OS: 75% vs 60% and 2 Year OS: 50% and 20% in AG and Pl-CT subgroups, respectively) as well.

CONCLUSIONS

Pl-CT does not seem to be associated with a better outcome compared to AG chemotherapy in PDAC patients with BRCA 1/2 VUS.

Clinical and genomic characterisation of early-onset pancreatic cancer

BACKGROUND

The incidence of early-onset pancreatic cancer (EOPC) has risen dramatically in recent years. We aimed to characterise the clinical and genomic features of EOPC and evaluate their therapeutic implications.

METHODS

We performed a comparative, single-centre, retrospective analysis of clinical, germline, and genomic features in EOPC (≤50 years) patients and compared them with a control group of average-onset pancreatic cancer patients (AOPC, ≥70 years). Key molecular findings were compared with an external, publicly available cohort.

RESULTS

We reviewed 336 patients who met all inclusion criteria (EOPC N = 139, AOPC N = 197). EOPC was associated with smoking status, lower prevalence of diabetes, better performance status, higher CA19.9 levels, and higher albumin levels at diagnosis. After adjustment for baseline covariates, we observed no differences in overall survival (OS). Age was associated with an increase in the incidence of KRASMUT both in our cohort and the validation cohort. EOPC were enriched in potentially actionable alterations according to ESCAT tiers I-IIIA when compared with AOPC in discovery and validation cohorts (19% versus 14% and 14% versus 8%, respectively). In the first-line metastatic setting, EOPC had a longer progression-free survival (hazard ratio [HR] 0.61, 95% confidence interval (CI) 0.43-0.87) and OS (HR 0.65, 95% CI 0.45-0.95), although there were no differences in response rate. After adjusting for the number of treatment lines, EOPC patients who did receive targeted therapies exhibited longer OS compared with EOPC who did not (HR 0.34, 95% CI 0.12-0.93).

CONCLUSIONS

EOPC patients have improved outcomes in the metastatic setting when compared to AOPC and are enriched for targetable alterations that open opportunities for precision oncology-based approaches.

Enzalutamide and olaparib synergistically suppress castration-resistant prostate cancer progression by promoting apoptosis through inhibiting nonhomologous end joining pathway

Recent studies revealed the relationship among homologous recombination repair (HRR), androgen receptor (AR), and poly(adenosine diphosphate-ribose) polymerase (PARP); however, the synergy between anti-androgen enzalutamide (ENZ) and PARP inhibitor olaparib (OLA) remains unclear. Here, we showed that the synergistic effect of ENZ and OLA significantly reduced proliferation and induced apoptosis in AR-positive prostate cancer cell lines. Next-generation sequencing followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed the significant effects of ENZ plus OLA on nonhomologous end joining (NHEJ) and apoptosis pathways. ENZ combined with OLA synergistically inhibited the NHEJ pathway by repressing DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and X-ray repair cross complementing 4 (XRCC4). Moreover, our data showed that ENZ could enhance the response of prostate cancer cells to the combination therapy by reversing the anti-apoptotic effect of OLA through the downregulation of anti-apoptotic gene insulin-like growth factor 1 receptor ( IGF1R ) and the upregulation of pro-apoptotic gene death-associated protein kinase 1 ( DAPK1 ). Collectively, our results suggested that ENZ combined with OLA can promote prostate cancer cell apoptosis by multiple pathways other than inducing HRR defects, providing evidence for the combined use of ENZ and OLA in prostate cancer regardless of HRR gene mutation status.

Germline BRCA testing in pancreatic cancer: improving awareness, timing, turnaround, and uptake

Prognosis is generally poor for patients with pancreatic ductal adenocarcinoma. However, patients with germline BRCA1 or BRCA2 mutations (gBRCAm) may benefit from first-line platinum-based chemotherapy and maintenance therapy with the poly(adenosine diphosphate-ribose) polymerase inhibitor olaparib following at least 16 weeks of first-line platinum-based chemotherapy without disease progression. Germline breast cancer gene (BRCA) testing is therefore important to ensure that patients receive the most effective treatment. In addition, testing for other DNA damage response gene mutations beyond gBRCAm may also guide treatment decisions. However, clinical pathways for genetic testing are often suboptimal, leading to delays in treatment initiation or missed opportunities for personalized therapy. Barriers to testing include low rates of referral and uptake, delays to referral and slow result turnaround times, cost, and biopsy and assay limitations if somatic testing is performed, leading to the requirement for subsequent dedicated germline testing. Low rates of referral may result from lack of awareness among physicians of the clinical value of testing, coupled with low confidence in interpreting test results and poor availability of genetic counseling services. Among patients, barriers to uptake may include similar lack of awareness of the clinical value of testing, anxiety regarding the implications of test results, lack of insurance coverage, fear of negative insurance implications, and socioeconomic factors. Potential solutions include innovative approaches to testing pathways, including 'mainstreaming' of testing in which BRCA tests are routinely arranged by the treating oncologist, with the involvement of genetic counselors if a patient is found to have a gBRCAm. More recently, the utility of multigene panel analyses has also been explored. Access to genetic counseling may also be improved through initiatives such as having a genetic counseling appointment for all new patient visits and telemedicine approaches, including the use of telephone consultations or DVD-assisted counseling. Educational programs will also be beneficial, and cost effectiveness is likely to improve as the number of targeted treatments increases and when the earlier detection of tumors in family members following cascade testing is considered.

Overcoming therapeutic resistance in pancreatic cancer: Emerging opportunities by targeting BRCAs and p53

Pancreatic cancer (PC) is characterized by (epi)genetic and microenvironmental alterations that negatively impact the treatment outcomes. New targeted therapies have been pursued to counteract the therapeutic resistance in PC. Aiming to seek for new therapeutic options for PC, several attempts have been undertaken to exploit BRCA1/2 and TP53 deficiencies as promising actionable targets. The elucidation of the pathogenesis of PC highlighted the high prevalence of p53 mutations and their connection with the aggressiveness and therapeutic resistance of PC. Additionally, PC is associated with dysfunctions in several DNA repair-related genes, including BRCA1/2, which sensitize tumours to DNA-damaging agents. In this context, poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) were approved for mutant BRCA1/2 PC patients. However, acquired drug resistance has become a major drawback of PARPi. This review emphasizes the importance of targeting defective BRCAs and p53 pathways for advancing personalized PC therapy, with particular focus on how this approach may provide an opportunity to tackle PC resistance.

Pancreatic Cancer: BRCA Targeted Therapy and Beyond

Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second leading cause of cancer-related death in the US by 2030, despite accounting for only 5% of all cancer diagnoses. Germline gBRCA1/2-mutated PDAC represents a key subgroup with a favorable prognosis, due at least in part to additional approved and guideline-endorsed therapeutic options compared with an unselected PDAC cohort. The relatively recent incorporation of PARP inhibition into the treatment paradigm for such patients has resulted in renewed optimism for a biomarker-based approach to the management of this disease. However, gBRCA1/2 represents a small subgroup of patients with PDAC, and efforts to extend the indication for PARPi beyond BRCA1/2 mutations to patients with PDAC and other genomic alterations associated with deficient DNA damage repair (DDR) are ongoing, with several clinical trials underway. In addition, despite an array of approved therapeutic options for patients with BRCA1/2-associated PDAC, both primary and acquired resistance to platinum-based chemotherapies and PARPi presents a significant challenge in improving long-term outcomes. Herein, we review the current treatment landscape of PDAC for patients with BRCA1/2 and other DDR gene mutations, experimental approaches under investigation or in development, and future directions.

Review of genetic and pharmacogenetic differences in cytotoxic and targeted therapies for pancreatic cancer in African Americans

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer mortality and the incidence is projected to increase by 2030. Despite recent advances in its treatment, African Americans have a 50-60% higher incidence and 30% higher mortality rate when compared to European Americans possibly resulting from differences in socioeconomic status, access to healthcare, and genetics. Genetics plays a role in cancer predisposition, response to cancer therapeutics (pharmacogenetics), and in tumor behavior, making some genes targets for oncologic therapeutics. We hypothesize that the germline genetic differences in predisposition, drug response, and targeted therapies also impact PDAC disparities. To demonstrate the impact of genetics and pharmacogenetics on PDAC disparities, a review of the literature was performed using PubMed with variations of the following keywords: pharmacogenetics, pancreatic cancer, race, ethnicity, African, Black, toxicity, and the FDA-approved drug names: Fluoropyrimidines, Topoisomerase inhibitors, Gemcitabine, Nab-Paclitaxel, Platinum agents, Pembrolizumab, PARP-inhibitors, and NTRK fusion inhibitors. Our findings suggest that the genetic profiles of African Americans may contribute to disparities related to FDA approved chemotherapeutic response for patients with PDAC. We recommend a strong focus on improving genetic testing and participation in biobank sample donations for African Americans. In this way, we can improve our current understanding of genes that influence drug response for patients with PDAC.

Dietary Factors and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses of Prospective Observational Studies

Dietary factors may be associated with the occurrence of pancreatic cancer. This umbrella review aimed to review and grade the evidence for the associations between dietary factors and pancreatic cancer risk. We searched PubMed, EMBASE, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and CINAHL for eligible literature. We included meta-analyses of randomized controlled trials (RCTs) or prospective observational studies. We used AMSTAR-2, a measurement tool to assess systematic reviews, to evaluate the methodological quality of the included meta-analyses. For each association, we calculated the summary effect size, 95% CI, heterogeneity, number of cases, 95% prediction interval, small-study effect, and excess significance bias. The protocol for this review was registered in the PROSPERO database (CRD42022333669). We included 41 meta-analyses of prospective observational studies describing 59 associations between dietary factors and pancreatic cancer risk. None of the retrieved meta-analyses included RCTs. No association was supported by convincing or highly suggestive evidence; however, there was suggestive evidence of a positive association between fructose intake and pancreatic cancer risk. There was weak evidence for an inverse association of nuts intake or adherence to the Mediterranean diet with pancreatic cancer incidence, and for positive associations between a higher intake of red meat or heavy alcohol intake and pancreatic cancer incidence. The remaining 54 associations were nonsignificant. Consistent with the American Institute for Cancer Research review, this umbrella review found that regular consumption of nuts and reduced intake of fructose, red meat, and alcohol were associated with a lower risk of pancreatic cancer. Emerging weak evidence supported an inverse association between adherence to the Mediterranean diet and pancreatic cancer risk. As some associations were rated as weak and most were considered nonsignificant, further prospective studies are needed to investigate the role of dietary factors and risk of pancreatic cancer. Adv Nutr 2023;xx:xx-xx.

A systematic review and meta-analysis of germline BRCA mutations in pancreatic cancer patients identifies global and racial disparities in access to genetic testing

BACKGROUND

Germline BRCA1 and BRCA2 mutations (gBRCAm) can inform pancreatic cancer (PC) risk and treatment but most of the available information is derived from white patients. The ethnic and geographic variability of gBRCAm prevalence and of germline BRCA (gBRCA) testing uptake in PC globally is largely unknown.

MATERIALS AND METHODS

We carried out a systematic review and prevalence meta-analysis of gBRCA testing and gBRCAm prevalence in PC patients stratified by ethnicity. The main outcome was the distribution of gBRCA testing uptake across diverse populations worldwide. Secondary outcomes included: geographic distribution of gBRCA testing uptake, temporal analysis of gBRCA testing uptake in ethnic groups, and pooled proportion of gBRCAm stratified by ethnicity. The study is listed under PROSPERO registration number #CRD42022311769.

RESULTS

A total of 51 studies with 16 621 patients were included. Twelve of the studies (23.5%) enrolled white patients only, 10 Asians only (19.6%), and 29 (56.9%) included mixed populations. The pooled prevalence of white, Asian, African American, and Hispanic patients tested per study was 88.7%, 34.8%, 3.6%, and 5.2%, respectively. The majority of included studies were from high-income countries (HICs) (64; 91.2%). Temporal analysis showed a significant increase only in white and Asians patients tested from 2000 to present (P < 0.001). The pooled prevalence of gBRCAm was: 3.3% in white, 1.7% in Asian, and negligible (<0.3%) in African American and Hispanic patients.

CONCLUSIONS

Data on gBRCA testing and gBRCAm in PC derive mostly from white patients and from HICs. This limits the interpretation of gBRCAm for treating PC across diverse populations and implies substantial global and racial disparities in access to BRCA testing in PC.

Overall Survival Results From the POLO Trial: A Phase III Study of Active Maintenance Olaparib Versus Placebo for Germline BRCA-Mutated Metastatic Pancreatic Cancer

PURPOSE

The phase III POLO study demonstrated significant progression-free survival (PFS) benefit for active olaparib maintenance therapy versus placebo for patients with metastatic pancreatic adenocarcinoma and a germline BRCA mutation. Here, we report the final analysis of overall survival (OS) and other secondary end points.

PATIENTS AND METHODS

Patients with a deleterious or suspected deleterious germline BRCA mutation whose disease had not progressed after ≥ 16 weeks of first-line platinum-based chemotherapy were randomly assigned 3:2 to active maintenance olaparib (300 mg twice daily) or placebo. The primary end point was PFS; secondary end points included OS, time to second disease progression or death, time to first and second subsequent cancer therapies or death, time to discontinuation of study treatment or death, and safety and tolerability.

RESULTS

In total, 154 patients were randomly assigned (olaparib, n = 92; placebo, n = 62). No statistically significant OS benefit was observed (median 19.0 v 19.2 months; hazard ratio [HR], 0.83; 95% CI, 0.56 to 1.22; P = .3487). Kaplan-Meier OS curves separated at approximately 24 months, and the estimated 3-year survival after random assignment was 33.9% versus 17.8%, respectively. Median time to first subsequent cancer therapy or death (HR, 0.44; 95% CI, 0.30 to 0.66; P < .0001), time to second subsequent cancer therapy or death (HR, 0.61; 95% CI, 0.42 to 0.89; P = .0111), and time to discontinuation of study treatment or death (HR, 0.43; 95% CI, 0.29 to 0.63; P < .0001) significantly favored olaparib. The HR for second disease progression or death favored olaparib without reaching statistical significance (HR, 0.66; 95% CI, 0.43 to 1.02; P = .0613). Olaparib was well tolerated with no new safety signals.

CONCLUSION

Although no statistically significant OS benefit was observed, the HR numerically favored olaparib, which also conferred clinically meaningful benefits including increased time off chemotherapy and long-term survival in a subset of patients.

C9orf16 represents the aberrant genetic programs and drives the progression of PDAC

Background

Pancreatic ductal adenocarcinoma (PDAC), constituting 90% of pancreatic cancers, is the fourth leading cause of cancer-related deaths in the world. Lack of early detection of PDAC contributes to its poor prognosis as patients are often diagnosed at an advanced stage of disease. This is mostly due to the lack of promising diagnostic and therapeutic targets and corresponding drugs.

Methods and results

Here, by bioinformatic analysis of single cell RNA-sequencing data on normal pancreas tissues, primary and metastatic PDAC tumors, we identified a promising PDAC biomarker, C9orf16. The expression of C9orf16, rarely detectable in normal epithelial cells, was upregulated in primary PDAC cancer cells and was further elevated in metastatic PDAC cancer cells. Gain or loss of function of C9orf16 demonstrated its critical functions in regulating the cell proliferation, invasion and chemotherapy resistance of cancer cells. Pathway analysis and functional studies identified MYC signaling pathways as the most activated pathways in regulating C9orf16 expression and in mediating the development and progression of PDAC.

Conclusions

These data suggested a crucial gene regulation system, MYC-C9orf16, which is actively involved in PDAC development and progression, and targeting this system should be a novel diagnostic and therapeutic target for PDAC.

Precision Medicine of Hepatobiliary and Pancreatic Cancers: Focusing on Clinical Trial Outcomes

Tumor-agnostic precision medicine employing comprehensive genome profiling (CGP) and using next-generation sequencing (NGS) has been progressing recently. This review focuses on precision medicine for advanced unresectable hepatobiliary and pancreatic cancers. In this paper, for biliary tract cancer (BTC), therapies that target several regulators of cancer cell growth, including isocitrate dehydrogenase 1 (IDH1), fibroblast growth factor receptor 2 (FGFR2) fusion, proto-oncogene B-Raf (BRAF), and human epidermal growth factor receptor 2 (HER2) alterations, are reviewed. For pancreatic ductal adenocarcinoma (PDAC), therapies for Kirsten rat sarcoma virus (KRAS) gene mutation G12C, neuregulin (NRG)1, and breast cancer type 1 and 2 susceptibility (BRCA1/2), gene alterations are summarized. On the other hand, precision medicine targets were not established for hepatocellular carcinoma (HCC), although telomerase reverse transcriptase (TERT), tumor protein P53 (TP53), and Wnt/β catenin signaling alterations have been recognized as HCC driver oncogenes. Tumor-agnostic therapies for microsatellite instability-high (MSI-H) and neurotropic tyrosine receptor kinase (NTRK) fusion cancers effectively treat biliary and pancreatic cancers. Precision medicine methods developed using NGS of circulating tumor DNA (ctDNA) and utilizing a liquid biopsy technique are discussed.

Current status and future perspectives of clinical research in pancreatic cancer: Establishment of evidence by science

Pancreatic cancer is one of the most aggressive diseases in the world due to a lack of early detection, leading to an overall 5-year survival of only 10%. In recent years, clinical trials targeted pancreatic cancer in efforts to improve survival. These studies introduce new technologies, concepts, and evidence which have instilled new optimism for improving prognosis. This review summarizes the current status of the recent (5-year) clinical trials and describes contemporary research on pancreatic cancer, including surgical technology, diagnostic skills, traditional chemoradiotherapy, neoadjuvant chemotherapy, immunotherapy, targeted therapy, and precision medicine. Then, the future trend and direction of clinical trials on pancreatic cancer are discussed.

Current status of inherited pancreatic cancer

Background

It is estimated that about 10% of pancreatic cancer cases have a genetic background. People with a familial predisposition to pancreatic cancer can be divided into 2 groups. The first is termed hereditary pancreatic cancer, which occurs in individuals with a known hereditary cancer syndrome caused by germline single gene mutations (e.g., BRCA1/2, CDKN2A). The second is considered as familial pancreatic cancer, which is associated with several genetic factors responsible for the more common development of pancreatic cancer in certain families, but the precise single gene mutation has not been found.

Aim

This review summarizes the current state of knowledge regarding the risk of pancreatic cancer development in hereditary pancreatic cancer and familial pancreatic cancer patients. Furthermore, it gathers the latest recommendations from the three major organizations dealing with the prevention of pancreatic cancer in high-risk groups and explores recent guidelines of scientific societies on screening for pancreatic cancers in individuals at risk for hereditary or familial pancreatic cancer.

Conclusions

In order to improve patients’ outcomes, authors of current guidelines recommend early and intensive screening in patients with pancreatic cancer resulting from genetic background. The screening should be performed in excellence centers. The scope, extent and cost-effectiveness of such interventions requires further studies.

The prostate cancer landscape in Europe: Current challenges, future opportunities

Prostate cancer (PCa) is the most common non-cutaneous cancer in men in Europe and is predicted to exhibit declining mortality in the European Union (EU) due to various recent improvements in treatment. The goal of this short review is to give insight into the European treatment landscape of PCa, while focusing on improvements in care.

Germline DNA damage repair gene mutations in pancreatic cancer patients with personal/family histories of pancreas/breast/ovarian/prostate cancer in a Japanese population

AIM

Cancer patients with personal/family histories of pancreatic/breast/ovarian/prostate cancer are associated with a higher likelihood of harboring DNA damage repair (DDR)-related germline mutations. Here, we aimed to obtain a better understanding of DDR-related germline mutations in Japanese pancreatic ductal adenocarcinoma (PDAC) patients with personal and/or family histories of BRCA-related cancers of the pancreas, breast, ovary, and prostate.

METHODS

We performed next-generation sequencing (NGS) and evaluated germline mutations in nine DDR-related genes (BRCA1, BRCA2, ATM, PALB2, CHEK2, MLH1, MSH2, MSH6, and PMS2) in PDAC patients with personal and/or family histories.

RESULTS

Of 196 patients with PDAC, 39 (19.9%) fulfilled the criteria for at least one family history of pancreatic/breast/ovarian/prostate cancer in first-degree relatives (sibling-sibling or parent-child) or the personal history of these malignancies. Targeted NGS revealed that four (10.2%) of 39 patients with personal/family histories harbored deleterious germline mutations-two in BRCA2, one in ATM, and one in MLH1. Both the BRCA2 variants showed frameshift mutations due to short insertion/deletions. In the 39 patients undergoing NGS, a similar distribution of the clinicopathological characteristics was observed between those with deleterious mutations/variants of unknown significance (VUSs) and with benign/wild types. Patients with deleterious germline mutations/VUSs in DDR-related genes showed a significantly more favorable prognosis than those with benign mutations/wild-type genes (hazard ratio: 0.160, P = .040).

CONCLUSIONS

A significant fraction of PDAC patients with personal/family histories of BRCA-related cancers harbored deleterious germline mutations in DDR-related genes. DDR-related germline gene mutations might be a favorable prognostic factor in patients with pancreatic cancer.

Pharmacoethnicity of FOLFIRINOX versus gemcitabine plus nab-paclitaxel in metastatic pancreatic cancer: a systematic review and meta-analysis

Treatment outcomes between FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) and GNP (gemcitabine with albumin-bound paclitaxel) as first-line chemotherapy regimens for metastatic pancreatic cancer (PC) were assessed according to ethnic groups categorized as Western or Asian subgroups. PubMed, EMBASE, and Cochrane library were searched. Thirteen studies were eligible in this meta-analysis. Overall survival was not significantly different between FOLFIRINOX and GNP (HR 1.00, 95% CI 0.83–1.20, P = 0.990). However, the Western subgroup showed a higher survival benefit for FOLFIRINOX over GNP (HR 0.84, 95% CI 0.74–0.95, P = 0.006) whereas the Asian subgroup showed the survival benefit for GNP over FOLFIRINOX (HR 1.29, 95% CI 1.03–1.60, P = 0.030). Progression free survival was not significantly different between the two regimens in the Western subgroup (HR 1.01, 95% CI 0.84–1.20, P = 0.950) and the Asian subgroup (HR 1.13, 95% CI 0.97–1.33, P = 0.110). Occurrence of febrile neutropenia was significantly higher in FOLFIRINOX at both ethnic subgroups; however, that of peripheral neuropathy was significantly higher only in GNP of the Asian subgroup. Therefore, pharmacoethnicity might be a factor worth considering when deciding on a frontline chemotherapeutic regimen although the overall survival was not significantly different between FOLFIRINOX and GNP for metastatic PCs.

Pancreatic Cancer: A Review

IMPORTANCE

Pancreatic ductal adenocarcinoma (PDAC) is a relatively uncommon cancer, with approximately 60 430 new diagnoses expected in 2021 in the US. The incidence of PDAC is increasing by 0.5% to 1.0% per year, and it is projected to become the second-leading cause of cancer-related mortality by 2030.

OBSERVATIONS

Effective screening is not available for PDAC, and most patients present with locally advanced (30%-35%) or metastatic (50%-55%) disease at diagnosis. A multidisciplinary management approach is recommended. Localized pancreas cancer includes resectable, borderline resectable (localized and involving major vascular structures), and locally advanced (unresectable) disease based on the degree of arterial and venous involvement by tumor, typically of the superior mesenteric vessels. For patients with resectable disease at presentation (10%-15%), surgery followed by adjuvant chemotherapy with FOLFIRINOX (fluorouracil, irinotecan, leucovorin, oxaliplatin) represents a standard therapeutic approach with an anticipated median overall survival of 54.4 months, compared with 35 months for single-agent gemcitabine (stratified hazard ratio for death, 0.64 [95% CI, 0.48-0.86]; P = .003). Neoadjuvant systemic therapy with or without radiation followed by evaluation for surgery is an accepted treatment approach for resectable and borderline resectable disease. For patients with locally advanced and unresectable disease due to extensive vascular involvement, systemic therapy followed by radiation is an option for definitive locoregional disease control. For patients with advanced (locally advanced and metastatic) PDAC, multiagent chemotherapy regimens, including FOLFIRINOX, gemcitabine/nab-paclitaxel, and nanoliposomal irinotecan/fluorouracil, all have a survival benefit of 2 to 6 months compared with a single-agent gemcitabine. For the 5% to 7% of patients with a BRCA pathogenic germline variant and metastatic PDAC, olaparib, a poly (adenosine diphosphate [ADB]-ribose) polymerase inhibitor, is a maintenance option that improves progression-free survival following initial platinum-based therapy.

CONCLUSIONS AND RELEVANCE

Approximately 60 000 new cases of PDAC are diagnosed per year, and approximately 50% of patients have advanced disease at diagnosis. The incidence of PDAC is increasing. Currently available cytotoxic therapies for advanced disease are modestly effective. For all patients, multidisciplinary management, comprehensive germline testing, and integrated supportive care are recommended.

Prevalence of Germline Pathogenic Variants in Cancer Predisposing Genes in Czech and Belgian Pancreatic Cancer Patients

Simple Summary

We performed genetic analysis of 53 cancer predisposing genes in Belgian and Czech pancreatic cancer patients. In known pancreatic cancer predisposing genes, a high mutation detection ratio was observed in patients with multiple primary tumors and/or a family history of pancreatic or breast, ovarian or colon cancer or melanoma. BRCA1, BRCA2, and ATM were most frequently affected. Pathogenic variants in cancer predisposition genes for which the association with pancreatic cancer has not been firmly established, were less frequent, except for CHEK2. This observation warrants further analyses in other populations. To accurately determine risk associations our study highlights the importance of using a geographically-matched control population.

Abstract

(1) Background: The proportion and spectrum of germline pathogenic variants (PV) associated with an increased risk for pancreatic ductal adenocarcinoma (PDAC) varies among populations. (2) Methods: We analyzed 72 Belgian and 226 Czech PDAC patients by multigene panel testing. The prevalence of pathogenic variants (PV) in relation to personal/family cancer history were evaluated. PDAC risks were calculated using both gnomAD-NFE and population-matched controls. (3) Results: In 35/298 (11.7%) patients a PV in an established PDAC-predisposition gene was found. BRCA1/2 PV conferred a high risk in both populations, ATM and Lynch genes only in the Belgian subgroup. PV in other known PDAC-predisposition genes were rarer. Interestingly, a high frequency of CHEK2 PV was observed in both patient populations. PV in PDAC-predisposition genes were more frequent in patients with (i) multiple primary cancers (12/38; 32%), (ii) relatives with PDAC (15/56; 27%), (iii) relatives with breast/ovarian/colorectal cancer or melanoma (15/86; 17%) but more rare in sporadic PDAC (5/149; 3.4%). PV in homologous recombination genes were associated with improved overall survival (HR = 0.51; 95% CI 0.34–0.77). (4) Conclusions: Our analysis emphasizes the value of multigene panel testing in PDAC patients, especially in individuals with a positive family cancer history, and underlines the importance of population-matched controls for risk assessment.

Targeting DNA Damage Repair Mechanisms in Pancreas Cancer

Impaired DNA damage repair (DDR) is increasingly recognised as a hallmark in pancreatic ductal adenocarcinoma (PDAC). It is estimated that around 14% of human PDACs harbour mutations in genes involved in DDR, including, amongst others, BRCA1/2, PALB2, ATM, MSH2, MSH6 and MLH1. Recently, DDR intervention by PARP inhibitor therapy has demonstrated effectiveness in germline BRCA1/2-mutated PDAC. Extending this outcome to the significant proportion of human PDACs with somatic or germline mutations in DDR genes beyond BRCA1/2 might be beneficial, but there is a lack of data, and consequently, no clear recommendations are provided in the field. Therefore, an expert panel was invited by the European Society of Digestive Oncology (ESDO) to assess the current knowledge and significance of DDR as a target in PDAC treatment. The aim of this virtual, international expert meeting was to elaborate a set of consensus recommendations on testing, diagnosis and treatment of PDAC patients with alterations in DDR pathways. Ahead of the meeting, experts completed a 27-question survey evaluating the key issues. The final recommendations herein should aid in facilitating clinical practice decisions on the management of DDR-deficient PDAC.

Targeting DNA damage repair pathways in pancreas cancer

Pancreas ductal adenocarcinoma (PDAC) is the third most common cause of cancer death in the USA. While other cancers with historically poor prognoses have benefited from new immunotherapies and targeted agents, the 5-year survival rate for PDAC patients has remained static. The accessibility to genomic testing has improved in recent years, and it is now clear that PDAC is a heterogenous disease, with a subset of patients harboring actionable mutations. There are several targeted therapies approved by the Food and Drug administration (FDA) in PDAC: EGFR inhibitor erlotinib (combined with gemcitabine) in unselected patients, TRK inhibitors larotrectinib and entrectinib for patients with NTRK fusion mutation, the PD-1 inhibitor pembrolizumab for mismatch repair-deficient patients, and the poly-ADP-ribose polymerase (PARP) inhibitor olaparib in patients with germline BRCA mutation as a maintenance therapy. DNA damage repair (DDR) is paramount to genomic integrity and cell survival. The defective repair of DNA damage is one of the hallmarks of cancer, and abnormalities in DDR pathways are closely linked with the development of malignancies and upregulation of these pathways linked with resistance to treatment. The prevalence of somatic and germline mutations in DDR pathways in metastatic PDAC is reported to be approximately 15-25%. Patients with DDR gene alterations benefit from a personalized approach to treatment. Recently, the POLO trial demonstrated a progression-free survival (PFS) benefit in metastatic PDAC patients with a germline BRCA1/2 mutation treated with maintenance olaparib following platinum-based induction chemotherapy. This was the first phase 3 randomized trial to establish a biomarker-driven approach in the treatment of PDAC and establishes a precedent for maintenance therapy in PDAC. The review herein aims to outline the current treatment landscape for PDAC patients with DDR gene-mutated tumors, highlight novel therapeutic approaches focused on surmounting tumor resistance, and explore new strategies which may lead to an expansion in the number of patients who benefit from these targeted treatments.

Homologous Recombination Deficiency in Pancreatic Cancer: A Systematic Review and Prevalence Meta-Analysis

PURPOSE

To analyze the prevalence of homologous recombination deficiency (HRD) in patients with pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis of the prevalence of HRD in PDAC from PubMed, Scopus, and Cochrane Library databases, and online cancer genomic data sets. The main outcome was pooled prevalence of somatic and germline mutations in the better characterized HRD genes (BRCA1, BRCA2, PALB2, ATM, ATR, CHEK2, RAD51, and the FANC genes). The secondary outcomes were prevalence of germline mutations overall, and in sporadic and familial cases; prevalence of germline BRCA1/2 mutations in Ashkenazi Jewish (AJ); and prevalence of HRD based on other definitions (ie, alterations in other genes, genomic scars, and mutational signatures). Random-effects modeling with the Freeman-Tukey transformation was used for the analyses. PROSPERO registration number: (CRD42020190813).

RESULTS

Sixty studies with 21,842 participants were included in the systematic review and 57 in the meta-analysis. Prevalence of germline and somatic mutations was BRCA1: 0.9%, BRCA2: 3.5%, PALB2: 0.2%, ATM: 2.2%, CHEK2: 0.3%, FANC: 0.5%, RAD51: 0.0%, and ATR: 0.1%. Prevalence of germline mutations was BRCA1: 0.9% (2.4% in AJ), BRCA2: 3.8% (8.2% in AJ), PALB2: 0.2%, ATM: 2%, CHEK2: 0.3%, and FANC: 0.4%. No significant differences between sporadic and familial cases were identified. HRD prevalence ranged between 14.5%-16.5% through targeted next-generation sequencing and 24%-44% through whole-genome or whole-exome sequencing allowing complementary genomic analysis, including genomic scars and other signatures (surrogate markers of HRD).

CONCLUSION

Surrogate readouts of HRD identify a greater proportion of patients with HRD than analyses limited to gene-level approaches. There is a clear need to harmonize HRD definitions and to validate the optimal biomarker for treatment selection. Universal HRD screening including integrated somatic and germline analysis should be offered to all patients with PDAC.

A systematic review of the prevalence of germline pathogenic variants in patients with pancreatic cancer

The genetics of pancreatic ductal adenocarcinoma (PDAC) is complex with patients reported to harbor germline pathogenic variants (PVs) in many different genes. PDAC patients with familial pancreatic cancer (FPC) are more likely to carry germline PVs but there is no consensus main gene involved in FPC. We performed a systematic review of publications from PubMed and Scopus reporting PVs in patients with FPC, sporadic pancreatic cancer (SPC) and unselected cohorts of PDAC patients undergoing genetic testing and calculated a cumulative prevalence of PVs for each gene evaluated across these three groups of patients. When available, variants in the selected publications were reclassified according to the American College of Medical Genetics and Genomics classification system and used for prevalence calculations if classified as pathogenic or likely pathogenic. We observed an increased prevalence of PVs in FPC compared to SPC or unselected PDAC patients for most of the 41 genes reported. The genes with the highest prevalence of carriers of PVs in FPC were ATM, BRCA2, and CDKN2A. BRCA2 and ATM showed the highest prevalence of PVs in both SPC and unselected PDAC cohorts. Several genes with the highest prevalence of PVs are involved in breast and ovarian cancer suggesting strong overlap with underlying genetics in these disorders but no single gene was predominant. More research is needed to further understand the risk of PDAC associated with these many diverse genes.

Application of natural killer cells in pancreatic cancer

Pancreatic cancer, a highly malignant disease, is characterized by rapid progression and early metastasis. Although the integrative treatment of pancreatic cancer has made great progress, the prognosis of patients with advanced pancreatic cancer remains extremely poor. In recent years, with the advancements in tumor immunology, immunotherapy has become a promising remedy for pancreatic cancer. Natural killer (NK) cells are the key lymphocytes in the innate immune system. NK cell function does not require antigen pre-sensitization and is not major histocompatibility complex restricted. By targeting tumors or virus-infected cells, the cells play a key role in immune surveillance. Although several questions about NK cells in pancreatic cancer still need to be further studied, there are extensive theories supporting the clinical application prospects of NK cell immunotherapy in pancreatic cancer. Since very few studies have evaluated the role of NK cells in pancreatic cancer, this review provides a comprehensive update of the role of NK cells in pancreatic cancer immunotherapy.

Genomic Features and Classification of Homologous Recombination Deficient Pancreatic Ductal Adenocarcinoma

BACKGROUND AND AIMS

Homologous recombination deficiency (HRD) in pancreatic ductal adenocarcinoma (PDAC), remains poorly defined beyond germline (g) alterations in BRCA1, BRCA2, and PALB2.

METHODS

We interrogated whole genome sequencing (WGS) data on 391 patients, including 49 carriers of pathogenic variants (PVs) in gBRCA and PALB2. HRD classifiers were applied to the dataset and included (1) the genomic instability score (GIS) used by Myriad's MyChoice HRD assay; (2) substitution base signature 3 (SBS3); (3) HRDetect; and (4) structural variant (SV) burden. Clinical outcomes and responses to chemotherapy were correlated with HRD status.

RESULTS

Biallelic tumor inactivation of gBRCA or PALB2 was evident in 43 of 49 germline carriers identifying HRD-PDAC. HRDetect (score ≥0.7) predicted gBRCA1/PALB2 deficiency with highest sensitivity (98%) and specificity (100%). HRD genomic tumor classifiers suggested that 7% to 10% of PDACs that do not harbor gBRCA/PALB2 have features of HRD. Of the somatic HRDetect^hi cases, 69% were attributed to alterations in BRCA1/2, PALB2, RAD51C/D, and XRCC2, and a tandem duplicator phenotype. TP53 loss was more common in BRCA1- compared with BRCA2-associated HRD-PDAC. HRD status was not prognostic in resected PDAC; however in advanced disease the GIS (P = .02), SBS3 (P = .03), and HRDetect score (P = .005) were predictive of platinum response and superior survival. PVs in gATM (n = 6) or gCHEK2 (n = 2) did not result in HRD-PDAC by any of the classifiers. In 4 patients, BRCA2 reversion mutations associated with platinum resistance.

CONCLUSIONS

Germline and parallel somatic profiling of PDAC outperforms germline testing alone in identifying HRD-PDAC. An additional 7% to 10% of patients without gBRCA/PALB2 mutations may benefit from DNA damage response agents.

Patient-derived xenograft models of BRCA-associated pancreatic cancers

Pancreatic ductal adenocarcinoma (PDAC) is a dismal disease. The majority of patients diagnosed at an advanced, metastatic stage, and poor overall survival rates. The most clinically meaningful subtype obtained from PDAC genomic classification is represented by unstable genomes, and co-segregated with inactivation of DNA damage repair genes, e.g., Breast cancer 1/2 (BRCA1/2). The FDA and EMA has recently approved olaparib, a Poly (ADP-ribose) polymerase (PARP) inhibitor, as a maintenance strategy for platinum-sensitive advanced PDAC patients with BRCA mutations. However, susceptibility to treatment varies, and resistance may develop. Resistance can be defined as innate or acquired resistance to platinum/PARP-inhibition. Patient-derived xenograft (PDX) models have been utilized in cancer research for many years. We generated a unique PDX model, obtained from BRCA-associated PDAC patients at distinct time points of the disease recapitulating the different clinical scenario. In this review we discuss the relevant PDX-derived models for investigating BRCA-associated PDAC and drug development.

Germinal BRCA1-2 pathogenic variants (gBRCA1-2pv) and pancreatic cancer: epidemiology of an Italian patient cohort

OBJECTIVE

Germline BRCA1-2 pathogenic variants (gBRCApv) increase the risk of pancreatic cancer and predict for response to platinating agents and poly(ADP-ribose) polymerase inhibitors. Data on worldwide gBRCApv incidence among pancreatic ductal adenocarcinoma (PDAC) patients are sparse and describe a remarkable geographic heterogeneity. The aim of this study is to analyze the epidemiology of gBRCApv in Italian patients.

MATERIALS AND METHODS

Patients of any age with pancreatic adenocarcinoma, screened within 3 months from diagnosis for gBRCApv in Italian oncologic centers systematically performing tests without any selection. For the purposes of our analysis, breast, ovarian, pancreas, and prostate cancer in a patient's family history was considered as potentially BRCA-associated. Patients or disease characteristics were examined using the χ2 test or Fisher's exact test for qualitative variables and the Student's t-test or Mann-Whitney test for continuous variables, as appropriate.

RESULTS

Between June 2015 and May 2020, 939 patients were tested by 14 Italian centers; 492 (52%) males, median age 62 years (range 28-87), 569 (61%) metastatic, 273 (29%) with a family history of potentially BRCA-associated cancers. gBRCA1-2pv were found in 76 patients (8.1%; 9.1% in metastatic; 6.4% in non-metastatic). The gBRCA2/gBRCA1 ratio was 5.4 : 1. Patients with gBRCApv were younger compared with wild-type (59 versus 62 years, P = 0.01). The gBRCApv rate was 17.1% among patients <40 years old, 10.4% among patients 41-50 years old, 9.2% among patients 51-60 years old, 6.7% among patients aged 61-70 years, and 6.2% among patients >70 years old (none out of 94 patients >73 years old). gBRCApv frequency in 845 patients <74 years old was 9%. Patients with/without a family history of potentially BRCA-associated tumors had 14%/6% mutations.

CONCLUSION

Based on our findings of a gBRCApv incidence higher than expected in a real-life series of Italian patients with incident PDAC, we recommend screening all PDAC patients <74 years old, regardless of family history and stage, due to the therapeutic implications and cancer risk prevention in patients' relatives.

Clinical Significance of Germline Cancer Predisposing Variants in Unselected Patients with Pancreatic Adenocarcinoma

Our aim was to determine the prevalence, prognostic and predictive role of germline pathogenic/likely pathogenic variants (P/LPVs) in cancer predisposing genes in patients with pancreatic ductal adenocarcinoma (PDAC). Germline testing of 62 cancer susceptibility genes was performed on unselected patients diagnosed from 02/2003 to 01/2020 with PDAC, treated at Hellenic Cooperative Oncology Group (HeCOG)-affiliated Centers. The main endpoints were prevalence of P/LPVs and overall survival (OS). P/LPVs in PDAC-associated and homologous recombination repair (HRR) genes were identified in 22 (4.0%) and 42 (7.7%) of 549 patients, respectively. P/LPVs were identified in 16 genes, including ATM (11, 2.0%) and BRCA2 (6, 1.1%), while 19 patients (3.5%) were heterozygotes for MUTYH P/LPVs and 9 (1.6%) carried the low-risk allele, CHEK2 p.(Ile157Thr). Patients carrying P/LPVs had improved OS compared to non-carriers (22.6 vs. 13.9 months, p = 0.006). In multivariate analysis, there was a trend for improved OS in P/LPV carriers (p = 0.063). The interaction term between platinum exposure and mutational status of HRR genes was not significant (p-value = 0.35). A significant proportion of patients with PDAC carries clinically relevant germline P/LPVs, irrespectively of age, family history or disease stage. The predictive role of these P/LPVs has yet to be defined. ClinicalTrials.gov Identifier: NCT03982446.

Molecular alterations and targeted therapy in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a malignancy characterized by a poor prognosis and high mortality rate. Genetic mutations and altered molecular pathways serve as targets in precise therapy. Using next-generation sequencing (NGS), these aberrant alterations can be identified and used to develop strategies that will selectively kill cancerous cells in patients with PDAC. The realization of targeted therapies in patients with PDAC may be summarized by three approaches. First, because oncogenes play a pivotal role in tumorigenesis, inhibition of dysregulated oncogenes is a promising method (Table 3). Numerous researchers are developing strategies to target oncogenes, such as KRAS, NRG1, and NTRK and related molecules, although most of the results are unsatisfactory. Accordingly, emerging strategies are being developed to target these oncogenes, including simultaneously inhibiting multiple molecules or pathways, modification of mutant residues by small molecules, and RNA interference. Second, researchers have attempted to reactivate inactivated tumour suppressors or modulate related molecules. TP53, CDKN2A and SMAD4 are three major tumour suppressors involved in PDAC. Advances have been achieved in clinical and preclinical trials of therapies targeting these three genes, and further investigations are warranted. The TGF-β-SMAD4 signalling pathway plays a dual role in PDAC tumorigenesis and participates in mediating tumour-stroma crosstalk and modulating the tumour microenvironment (TME); thus, molecular subtyping of pancreatic cancer according to the SMAD4 mutation status may be a promising precision oncology technique. Finally, genes such as KDM6A and BRCA have vital roles in maintaining the structural stability and physiological functions of normal chromosomes and are deficient in some patients with PDAC, thus serving as potential targets for correcting these deficiencies and precisely killing these aberrant tumour cells. Recent clinical trials, such as the POLO (Pancreas Cancer Olaparib Ongoing) trial, have reported encouraging outcomes. In addition to genetic event-guided treatment, immunotherapies such as chimeric antigen receptor T cells (CAR-T), antibody-drug conjugates, and immune checkpoint inhibitors also exhibit the potential to target tumours precisely, although the clinical value of immunotherapies as treatments for PDAC is still limited. In this review, we focus on recent preclinical and clinical advances in therapies targeting aberrant genes and pathways and predict the future trend of precision oncology for PDAC.

PARP inhibition in treatment of pancreatic cancer

INTRODUCTION

Tumor control and survival of patients with metastatic pancreatic ductal adenocarcinoma (PDAC) has improved with more effective polychemotherapies. The identification of novel therapeutic targets is strongly needed in order to propose maintenance therapies that improve quality of life while maintaining tumor control.

AREAS COVERED

PDAC with mutations in homologous recombination repair genes such as BRCA are particularly sensitive to platinum agents. Recently, the potential role of poly(ADP-ribose) polymerase (PARP) inhibitors was suggested. The POLO study has shown that olaparib was efficient and well-tolerated as maintenance therapy in patients with germline BRCA1/2 mutation and a metastatic PDAC controlled after a platinum-based induction chemotherapy.

EXPERT OPINION

The demonstration of olaparib efficacy in patients with metastatic PDAC and BRCA germline mutation has paved the way for maintenance with a targeted therapy. Further studies are needed to assess; the potential role for PARPI in earlier forms of PDAC, those with somatic or more rare BRACness signatures, to overcome primary or secondary resistances to PARPi, and to combine them with other antitumoral agents.

Maintenance therapies in metastatic pancreatic cancer: present and future with a focus on PARP inhibitors

Metastatic pancreatic ductal adenocarcinomas (PDACs) are now more effectively controlled using chemotherapy combinations such as FOLFIRINOX and gemcitabine plus nab-paclitaxel (NabP) regimens with a subset of patients who achieve a sustained tumor stabilization or response. The next challenge is to design maintenance therapies that result in continued tumor control with minimal toxicity. Quality of life should always be a priority in these patients with prolonged survival. Gradually tapering off the intensity of chemotherapy by suppressing drug(s) in the combination is one option. Thus, maintenance with 5-fluorouracil or gemcitabine as single agents after FOLFIRINOX or gemcitabine-NabP induction, respectively, seems to be a promising approach to minimize neurotoxicity while maintaining efficacy. Another option is to introduce maintenance drug(s) with different anti-tumoral actions. The recent example of olaparib in patients with BRCA mutated PDAC provides a promising proof-of-concept of a switch maintenance strategy in this setting.