Clinical characteristics of pancreatic and biliary tract cancers in Lynch syndrome: A retrospective analysis from the Finnish National Lynch Syndrome Research Registry

Survival of Patients with Resected Microsatellite Instability-High, Mismatch Repair Deficient, and Lynch Syndrome-Associated Pancreatic Ductal Adenocarcinomas

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) remains a challenging disease due to its aggressiveness, late-stage diagnosis, and limited treatment options. Microsatellite instability-high (MSI-H) cancers are susceptible to immune checkpoint inhibitors. Survival outcomes for patients with MSI-H PDAC are unknown as the disease is rare.

METHODS

This study included patients with PDACs surgically resected from 1990 to 2023, and those with germline or sporadic pathogenic variants in DNA mismatch repair genes were identified. The study matched MSI-H, mismatch repair-deficient (MMRd), and Lynch syndrome (LS)-associated PDAC cases (on age, gender, and year of surgery) with microsatellite-stable (MSS), mismatch repair-proficient, or non-LS-associated PDAC cases in a 1:2 ratio. A generalized estimating equation Cox model with a robust sandwich estimator was used to compare overall survival (OS) in the matched cohorts.

RESULTS

Of 936 cases, 18 were included. Eight cases were MSI-H/MMRd, two were MSI/IHC-indeterminate, seven were MSS, and one was not tested for MSI. Nine patients had LS (MLH1 [n = 1], MSH2 [n = 4], MSH6 [n = 1], PMS2 [n = 3]), and nine patients had sporadic pathogenic variants in DNA MMR genes (MLH1 [n = 4], MSH6 [n = 5]). After matching to 36 control patients, the MSI-H/MMRd/LS PDACs had a significantly better OS (hazard ratio [HR], 0.36 [95% confidence interval [CI], 0.18-0.73; p = 0.005]; 5-year OS: MSI-H 77% [95% CI 58-100%] vs. MSS 27% [95% CI 15-51%]).

CONCLUSION

Before routine use of immune checkpoint inhibitors, the patients with MSI-H, MMRd, and LS-associated PDACs displayed significantly better survival than the patients with MSS, MMR-proficient, non-LS-associated PDACs. It is expected that survival for this cohort will further improve with increased availability of immunotherapy.

Clinical Implications of Mismatch Repair Deficiency in Pancreatic Ductal Adenocarcinoma

BACKGROUND

Pancreatic cancer is a highly aggressive and lethal disease, characterized by a limited response to chemotherapy and overall poor prognosis. Pancreatic cancers with a distinct mismatch repair deficiency, although relatively rare, have been shown to be associated with markedly better outcomes in comparison. Furthermore, whereas pancreatic cancers are generally unresponsive to current immunotherapy, this specific group of tumors has been shown to have a notable susceptibility to immune checkpoint inhibitors.

AIMS

In this review, we aim to summarize the relevant literature regarding mismatch-repair associated pancreatic cancers, the impacted biological mechanisms, and the resulting vulnerabilities for potential opportunistic immunotherapeutic treatment approaches. We will also review the current clinical studies assessing survival outcomes of mismatch repair deficient pancreatic cancers and ongoing clinical trials in this emerging field.

RESULTS AND CONCLUSIONS

Patients with dMMR/MSI-H pancreatic cancers harbor a distinct phenotype that has increased immune activation, greater responsiveness to immune checkpoint inhibitor therapy and better overall survival when compared to other pancreatic cancers. Although this molecular subtype makes up a small minority of cases, emerging data suggest immunotherapy may offer benefit to these patients.

Hereditary Pancreatic Cancer: Advances in Genetic Testing, Early Detection Strategies, and Personalized Management

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a five-year survival rate of approximately 13% for advanced stages. While the majority of PDAC cases are sporadic, a significant subset is attributable to hereditary and familial predispositions, accounting for approximately 25% of cases. This article synthesizes recent advancements in the understanding, detection, and management of hereditary pancreatic cancer (PC). Results: Our review highlights the critical role of genetic testing (GT) in identifying high-risk individuals (HRIs), with germline pathogenic variants (PVs) found in up to 20% of hereditary PDAC cases. Since the implementation of next-generation sequencing (NGS) panels in 2014, detection capabilities have been significantly enhanced. HRIs can be included in screening programs that facilitate the early detection of PDAC. Early detection strategies, including the use of microribonucleic acid (miRNAs) signatures and novel imaging techniques like hyperpolarized 13C-magnetic resonance spectroscopy (MRS) have shown promising results. The identification of germline pathogenic variants (PVs) or mutations in homologous recombination (HR) genes plays a predictive role in the response to various treatments, prolonging patient survival. Discussion: Universal germline testing for PDAC, as recommended by the National Comprehensive Cancer Network (NCCN), is now a standard practice, facilitating the identification of at-risk individuals and enabling targeted surveillance and intervention. Multidisciplinary management, integrating genetic counseling, imaging, and gastrointestinal services, is essential for optimizing outcomes. Conclusions: Advances in genetic testing and biomarker research are transforming the landscape of hereditary PC management. Early detection and personalized treatment strategies are pivotal in improving survival rates. Ongoing multi-institutional research efforts are crucial for validating biomarkers and developing preventive measures, ultimately aiming to reduce the burden of this aggressive cancer.

Lynch Syndrome and Somatic Mismatch Repair Variants in Pancreas Cancer

Importance

Microsatellite (MS) instability (MSI-H) occurs frequently in Lynch syndrome (LS)-associated tumors and is associated with response to immune checkpoint blockade (ICB) therapy. MSI-H is conferred by germline or somatic variants in mismatch repair genes. The contribution of somatic oncogenesis to MSI-H in pancreatic cancer (PC) is unknown.

Objective

To evaluate an LS-related PC cohort to define clinicogenomic features, describe somatic MSI-H cases (germline negative), characterize response to ICB, and guide preferred MS testing methods.

Design, Setting, and Participants

This single-institution, retrospective analysis was conducted from March 2012 to July 2023 at Memorial Sloan Kettering Cancer Center and included 55 patients with PC and either an LS germline pathogenic variant (gPV) or somatic mismatch repair (MMR) variant.

Main Outcomes and Measures

Composite MMR and MS status determined using orthogonal methods. An artificial intelligence classifier was used to account for low-cellularity specimens. Demographic and clinical data were abstracted from medical record. Zygosity status and somatic comutation landscape analyzed.

Results

Fifty-five patients (23 women [42%]) had PC and an MMR variant: 32 (58%) had LS (LS cohort) and 23 (42%) had a somatic MMR variant (no germline pathogenic variant, somatic MMR cohort). In the LS cohort, 10 (31%) had gMSH2, 9 (28%) gMSH6, 8 (25%) gPMS2, 4 (13%) gMLH1, 1 (3%) gEPCAM. The median age at diagnosis was 68 years (range, 45-88 years). For composite MS status, 17 (59%) were MSI-H, 12 (41%) MS stable, and 3 MS unknown. Five cases were reclassified as MSI-H by the artificial intelligence classifier. In the somatic MMR cohort, 11 (48%) had MSH6, 7 (30%) MLH1, 3 (13%) MSH2, and 2 (9%) PMS2. The median age at diagnosis was 72 years (range, 66-85 years). For composite MS status, 10 (43%) were MSI-H, 11 (48%) MS stable, and 2 (9%) MS indeterminate. Six cases were reclassified as MSI-H by the artificial intelligence classifier. For the LS and somatic MMR cohorts, 20 received ICB (n = 17 MSI-H). The median ICB duration was 27.7 months (95% CI, 11.5 to not reached); the disease control rate was 80%.

Conclusion

The results of this cross-sectional study suggest that MSI-H occurs due to LS or somatic oncogenesis in PC. Orthogonal MS testing is key in PC; the artificial intelligence classifier reclassified approximately 20% of cases, most of which were low cellularity. ICB for patients with LS or somatic MSI-H PC provided significant benefit.

Upper Gastrointestinal Cancers and the Role of Genetic Testing

Beyond the few established hereditary cancer syndromes with an upper gastrointestinal cancer component, there is increasing recognition of the contribution of novel pathogenic germline variants (gPVs) to upper gastrointestinal carcinogenesis. The detection of gPVs has potential implications for novel treatment approaches of the index cancer patient as well as long-term implications for surveillance and risk-reducing measures for cancer survivors and far-reaching implications for the patients' family. With widespread availability of multigene panel testing, new associations may be identified with germline-somatic integration being critical to determining true causality of novel gPVs. Comprehensive cancer care should incorporate both somatic and germline testing.

Hyperthermia combined with chemotherapy vs chemotherapy in patients with advanced pancreatic cancer: A multicenter retrospective observational comparative study

BACKGROUND

Several studies report the useful therapeutic results of regional hyperthermia in association with chemotherapy (CHT) and radiotherapy for the treatment of pancreatic cancer. Modulated electro-hyperthermia (mEHT) is a new hyperthermia technique that induces immunogenic death or apoptosis of pancreatic cancer cells in laboratory experiments and increases tumor response rate and survival in pancreatic cancer patients, offering beneficial therapeutic effects against this severe type of cancer.

AIM

To assess survival, tumor response and toxicity of mEHT alone or combined with CHT compared with CHT for the treatment of locally advanced or metastatic pancreatic cancer.

METHODS

This was a retrospective data collection on patients affected by locally advanced or metastatic pancreatic cancer (stage III and IV) performed in 9 Italian centers, members of International Clinical Hyperthermia Society-Italian Network. This study included 217 patients, 128 (59%) of them were treated with CHT (no-mEHT) and 89 (41%) patients received mEHT alone or in association with CHT. mEHT treatments were performed applying a power of 60-150 watts for 40-90 min, simultaneously or within 72 h of administration of CHT.

RESULTS

Median patients' age was 67 years (range 31-92 years). mEHT group had a median overall survival greater than non-mEHT group (20 mo, range 1.6-24, vs 9 mo, range 0.4-56.25, P < 0.001). mEHT group showed a higher number of partial responses (45% vs 24%, P = 0.0018) and a lower number of progressions (4% vs 31%, P < 0.001) than the no-mEHT group, at the three months follow-up. Adverse events were observed as mild skin burns in 2.6% of mEHT sessions.

CONCLUSION

mEHT seems safe and has beneficial effects on survival and tumor response of stage III-IV pancreatic tumor treatment. Further randomized studies are warranted to confirm or not these results.