Clinical Updates for Gastrointestinal Malignancies

Gastrointestinal (GI) cancers include hepatobiliary tumors, pancreatic cancer (PC), neuroendocrine tumors of the gastrointestinal tract, small bowel carcinomas, gastric cancer (GC), anal canal cancer, primary gastric and intestinal lymphomas, gastrointestinal stromal tumors (GISTs) and the most frequent colorectal cancer (CRC) [...].

Review of Current Systemic Therapy and Novel Systemic Therapy for Pancreatic Ductal Adenocarcinoma

BACKGROUND

This review aims to describe the systemic treatment options for pancreatic ductal adenocarcinoma and includes a summary of the current treatments as well as the ongoing clinical trials which may be efficacious in the treatment of this aggressive malignancy.

METHODS

A literature review was performed using MEDLINE/PubMed between August 1996 and February 2023. The reviewed studies are categorized into these categories: current standard of care treatments, targeted therapies, immunotherapy and clinical trials. The current treatment modality for the treatment of advanced pancreatic cancer is mainly systemic chemotherapy.

RESULTS

The introduction of polychemotherapy regimens including gemcitabine/nab-paclitaxel and FOLFIRINOX (oxaliplatin, irinotecan, folinic acid and fluorouracil) has improved the clinical outcome of advanced pancreatic cancer. For further improvement in clinical outcomes, several novel approaches have been extensively studied in pancreatic cancer. The review discusses the current standard chemotherapy regimen and the novel treatment options in the field.

CONCLUSIONS

While there are novel treatments being explored for metastatic pancreatic, it remains a debilitating and aggressive disease with high mortality that warrants continued efforts to advance therapeutic options.

Strategies for the Management of Patients with Pancreatic Cancer with PARP Inhibitors

A subset of patients with pancreatic adenocarcinomas (PDAC) harbor mutations that are exploitable in the context of DNA-damage response and repair (DDR) inhibitory strategies. Between 8-18% of PDACs harbor specific mutations in the DDR pathway such as BRCA1/2 mutations, and a higher prevalence exists in high-risk populations (e.g., Ashkenazi Jews). Herein, we will review the current trials and data on the treatment of PDAC patients who harbor such mutations and who appear sensitive to platinum and/or poly ADP ribose polymerase inhibitor (PARPi) based therapies due to a concept known as synthetic lethality. Although this current best-in-class precision treatment shows clinical promise, the specter of resistance limits the extent of therapeutic responses. We therefore also evaluate promising pre-clinical and clinical approaches in the pipeline that may either work with existing therapies to break resistance or work separately with combination therapies against this subset of PDACs.

Pathologic complete response following FOLFIRINOX and olaparib treatment for hepatic metastasized pancreatic ductal adenocarcinoma with a germline BRCA mutation

A 47-year-old female who was previously treated for BRCA1 germline mutant breast cancer presented with increasing back pain. Radiological and pathological investigations led to the diagnosis of pancreatic ductal adenocarcinoma with multiple hepatic metastases. Serum carbohydrate antigen 19-9 levels were highly elevated at 14,784 U/mL (normal, < 37 U/mL). After nine cycles of FOLFIRINOX treatment, radiological findings revealed remarkable shrinkage of the primary pancreatic tumor, disappearance of hepatic metastases, and normalized levels of carbohydrate antigen 19-9 levels. Because of increased neuropathy following FOLFIRINOX treatment, the patient was switched to maintenance olaparib treatment. Ten months later, her radiological response and normalized carbohydrate antigen 19-9 levels were stable. After staging laparoscopy, the patient underwent laparoscopic distal pancreatectomy as a conversion surgery. Histopathological examination revealed no signs of residual adenocarcinoma in the resected pancreatic specimens, which was diagnosed as a pathological complete response. The patient recovered without complications. Adjuvant olaparib treatment was administered with no signs of recurrence at 7 months after surgery. In conclusion, a pathologic complete response after FOLFIRINOX and olaparib maintenance treatment in hepatic metastasized pancreatic ductal adenocarcinoma is extremely rare. These bridging treatments may contribute to increased surgical resection rates and improved survival rates.

Current Limitations and Novel Perspectives in Pancreatic Cancer Treatment

Simple Summary

This review article presents a synopsis of the key clinical developments, their limitations, and future perspectives in the treatment of pancreatic cancer. In the first part, we summarize the available treatments for pancreatic cancer patients according to tumor stage, as well as the most relevant clinical trials over the past two decades. Despite this progress, there is still much to be improved in terms of patient survival. Therefore, in the second part, we consider various components of the tumor microenvironment in pancreatic cancer, looking for the key drivers of therapy resistance and tumor progression, which may lead to the discovery of new potential targets. We also discuss the most prominent molecules targeting the stroma and immune compartment that are being investigated in either preclinical or clinical trials. Finally, we also outline interesting venues for further research, such as possible combinations of therapies that may have the potential for clinical application.

Abstract

Pancreatic cancer is one of the deadliest cancers worldwide, largely due to its aggressive development. Consequently, treatment options are often palliative, as only one-fifth of patients present with potentially curable tumors. The only available treatment with curative intent is surgery followed by adjuvant chemotherapy. However, even for patients that are eligible for surgery, the 5-year OS remains below 10%. Hence, there is an urgent need to find new therapeutic regimens. In the first part of this review, we discuss the tumor staging method and its impact on the corresponding current standard-of-care treatments for PDAC. We also consider the key clinical trials over the last 20 years that have improved patient survival. In the second part, we provide an overview of the major components and cell types involved in PDAC, as well as their respective roles and interactions with each other. A deeper knowledge of the interactions taking place in the TME may lead to the discovery of potential new therapeutic targets. Finally, we discuss promising treatment strategies targeting specific components of the TME and potential combinations thereof. Overall, this review provides an overview of the current challenges and future perspectives in the treatment of pancreatic cancer.

Prognostic Significance of Disease Control at 12 Weeks in Patients With Advanced Pancreatic Cancer Receiving FOLFIRINOX as First-line Chemotherapy

OBJECTIVES

The POLO (Pancreas Cancer Olaparib Ongoing) trial demonstrated improvement in progression-free survival (PFS) with olaparib maintenance in advanced pancreatic cancer (APC) patients with germline BRCA1/2 mutations who had disease control after 16 weeks of platinum-based first-line therapy. However, in the real-world, the first assessment is usually performed at 12 weeks. Therefore, this study aimed to identify the proportion of real-world patients with APC that have disease control at 12 weeks (DC12) after FOLFIRINOX, assess any associations of baseline variables with DC12, and to determine the effect of DC12 on PFS and overall survival (OS).

METHODS

APC patients treated with first-line FOLFIRINOX from 2011 to 2018 in Alberta, Canada, were identified. We conducted an analysis of baseline characteristics to identify factors associated with DC12 and to compare the PFS and OS of patients with DC12 to those with earlier disease progression.

RESULTS

We identified 165 APC patients treated with FOLFIRINOX with unknown BRCA1/2 status, of which 56% were men, and the median age at diagnosis was 59 years (interquartile range, 38 to 75 y). Of these, 72 (44%) had DC12. Lower serum carbohydrate antigen 19.9 and normal serum albumin were associated with a higher likelihood of DC12. The PFS and OS of patients with DC12 was significantly higher than those with earlier progression (9.3 vs. 2.5 mo; hazard ratio, 0.22; 95% confidence interval, 0.15-0.32; P<0.001; 21.6 vs. 8.9 mo; hazard ratio, 0.35; 95% confidence interval, 0.25-0.49; P<0.0001).

CONCLUSION

Less than half of real-world patients treated with first-line FOLFIRINOX have DC12. Patients with APC who have higher carbohydrate antigen 19.9 and low albumin are less likely to have DC12. DC12 is significantly associated with longer PFS and OS.

Defining the Comprehensive Genomic Landscapes of Pancreatic Ductal Adenocarcinoma Using Real-World Endoscopic Aspiration Samples

PURPOSE

Most patients with pancreatic ductal adenocarcinoma (PDAC) present with surgically unresectable cancer. As a result, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the most common biospecimen source available for diagnosis in treatment-naïve patients. Unfortunately, these limited samples are often not considered adequate for genomic analysis, precluding the opportunity for enrollment on precision medicine trials.

EXPERIMENTAL DESIGN

Applying an epithelial cell adhesion molecule (EpCAM)-enrichment strategy, we show the feasibility of using real-world EUS-FNA for in-depth, molecular-barcoded, whole-exome sequencing (WES) and somatic copy-number alteration (SCNA) analysis in 23 patients with PDAC.

RESULTS

Potentially actionable mutations were identified in >20% of patients. Further, an increased mutational burden and higher aneuploidy in WES data were associated with an adverse prognosis. To identify predictive biomarkers for first-line chemotherapy, we developed an SCNA-based complexity score that was associated with response to platinum-based regimens in this cohort.

CONCLUSIONS

Collectively, these results emphasize the feasibility of real-world cytology samples for in-depth genomic characterization of PDAC and show the prognostic potential of SCNA for PDAC diagnosis.

A new targeted treatment for patients with a germline BRCA mutation: olaparib in pancreatic cancer

Pancreatic cancer has a poor prognosis. Focused efforts in the development of novel treatments of this disease have led to the approval of new combinations. Improvements in knowledge of the biology of these tumors have been made, and it is now widely accepted that a proportion of patients have potentially targetable altered genes. One such gene is BRCA, which confers sensibility to PARP inhibitors. Olaparib, an oral PARP inhibitor, initially demonstrated activity in Phase II clinical trials including germline BRCA-mutated patients. This was confirmed in a Phase III clinical trial in pancreatic cancer patients with a germline BRCA mutation. After the results of this study, new scenarios have been evoked. We review the development of olaparib in pancreatic cancer.

Increased Rate of Complete Pathologic Response After Neoadjuvant FOLFIRINOX for BRCA Mutation Carriers with Borderline Resectable Pancreatic Cancer

BACKGROUND

Neoadjuvant FOLFIRINOX is a standard-of-care treatment for BRPC patients. Patients with gBRCAm who have demonstrated improved response to platinum-based chemotherapy may have impaired homologous repair deficiency. This study aimed to describe the pathologic complete response rate and long-term survival for patients with germline BRCA1 or BRCA2 mutation (gBRCAm) and borderline resectable pancreatic cancer (BRPC) treated with neoadjuvant FOLFIRINOX.

METHODS

A dual-center retrospective analysis was performed. Patients who had BRPC treated with neoadjuvant FOLFIRINOX followed by curative resection were identified from clinical databases. Pathologic complete response was defined as no viable tumor cells present in the specimen. Common founder Jewish germline BRCA1 or BRCA2 mutation was determined for available patients.

RESULTS

The 61 BRPC patients in this study underwent resection after neoadjuvant FOLFIRINOX. Analysis of BRCA mutation was performed for 39 patients, and 9 patients were found to be BRCA2 germline mutation carriers. The pathologic complete response rate was 44.4% for the gBRCAm patients and 10% for the BRCA non-carriers (p = 0.009). The median disease-free survival was not reached for the gBRCAm patients and was 7 months for the BRCA non-carriers (p = 0.03). The median overall survival was not reached for the gBRCAm patients and was 32 months for the BRCA non-carriers (p = 0.2). After a mean follow-up period of 33.7 months, all eight patients with pathologic complete response were disease-free.

CONCLUSIONS

The study showed that gBRCAm patients with BRPC have an increased chance for pathologic complete response and prolonged survival after neoadjuvant FOLFIRINOX. The results support the benefit of exposing gBRCAm patients to platinum-based chemotherapy early in the course of the disease. Neoadjuvant FOLFIRINOX should be considered for BRCA carriers who have resectable pancreatic cancer.

Maintenance Olaparib for Germline BRCA-Mutated Metastatic Pancreatic Cancer

BACKGROUND

Patients with a germline BRCA1 or BRCA2 mutation make up a small subgroup of those with metastatic pancreatic cancer. The poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor olaparib has had antitumor activity in this population.

METHODS

We conducted a randomized, double-blind, placebo-controlled, phase 3 trial to evaluate the efficacy of olaparib as maintenance therapy in patients who had a germline BRCA1 or BRCA2 mutation and metastatic pancreatic cancer and disease that had not progressed during first-line platinum-based chemotherapy. Patients were randomly assigned, in a 3:2 ratio, to receive maintenance olaparib tablets (300 mg twice daily) or placebo. The primary end point was progression-free survival, which was assessed by blinded independent central review.

RESULTS

Of the 3315 patients who underwent screening, 154 underwent randomization and were assigned to a trial intervention (92 to receive olaparib and 62 to receive placebo). The median progression-free survival was significantly longer in the olaparib group than in the placebo group (7.4 months vs. 3.8 months; hazard ratio for disease progression or death, 0.53; 95% confidence interval [CI], 0.35 to 0.82; P = 0.004). An interim analysis of overall survival, at a data maturity of 46%, showed no difference between the olaparib and placebo groups (median, 18.9 months vs. 18.1 months; hazard ratio for death, 0.91; 95% CI, 0.56 to 1.46; P = 0.68). There was no significant between-group difference in health-related quality of life, as indicated by the overall change from baseline in the global quality-of-life score (on a 100-point scale, with higher scores indicating better quality of life) based on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (between-group difference, -2.47 points; 95% CI, -7.27 to 2.33). The incidence of grade 3 or higher adverse events was 40% in the olaparib group and 23% in the placebo group (between-group difference, 16 percentage points; 95% CI, -0.02 to 31); 5% and 2% of the patients, respectively, discontinued the trial intervention because of an adverse event.

CONCLUSIONS

Among patients with a germline BRCA mutation and metastatic pancreatic cancer, progression-free survival was longer with maintenance olaparib than with placebo. (Funded by AstraZeneca and others; POLO ClinicalTrials.gov number, NCT02184195.).