5-fluorouracil and cardiotoxicity: a review

Fluoropyrimidines such as 5-fluorouracil (5-FU) form the foundation of a wide variety of chemotherapy regimens. 5-FU is in fact the third most commonly used chemotherapeutic agent in the treatment of solid malignancies across the world. As with all chemotherapy, balancing the potential benefits of therapy against the risks of drug-related toxicity is crucial when clinicians and patients make shared decisions about treatment. 5-FU is the second most common chemotherapeutic drug associated with cardiotoxicity after anthracyclines, which can manifest as chest pain, acute coronary syndrome/myocardial infarction or death. Nevertheless a widespread appreciation of 5-FU-related cardiotoxicity and its implications is lacking amongst clinicians. In this review, we outline the incidence, possible risk factors, and likely pathophysiological mechanisms that may account for 5-FU-related cardiotoxicity and also highlight potential management strategies for this poorly understood clinical entity.

Early stage colon cancer: Current treatment standards, evolving paradigms, and future directions

Colon cancer continues to be one of the leading causes of mortality and morbidity throughout the world despite the availability of reliable screening tools and effective therapies. The majority of patients with colon cancer are diagnosed at an early stage (stages I to III), which provides an opportunity for cure. The current treatment paradigm of early stage colon cancer consists of surgery followed by adjuvant chemotherapy in a select group of patients, which is directed at the eradication of minimal residual disease to achieve a cure. Surgery alone is curative for the vast majority of colon cancer patients. Currently, surgery and adjuvant chemotherapy can achieve long term survival in about two-thirds of colon cancer patients with nodal involvement. Adjuvant chemotherapy is recommended for all patients with stage III colon cancer, while the benefit in stage II patients is not unequivocally established despite several large clinical trials. Contemporary research in early stage colon cancer is focused on minimally invasive surgical techniques, strategies to limit treatment-related toxicities, precise patient selection for adjuvant therapy, utilization of molecular and clinicopathologic information to personalize therapy and exploration of new therapies exploiting the evolving knowledge of tumor biology. In this review, we will discuss the current standard treatment, evolving treatment paradigms, and the emerging biomarkers, that will likely help improve patient selection and personalization of therapy leading to superior outcomes.

Targeted Therapies in Advanced Biliary Tract Cancer: An Evolving Paradigm

Biliary tract cancers (BTCs) are a heterogeneous group of adenocarcinomas that originate from the epithelial lining of the biliary tree. BTCs are characterized by presentation with advanced disease precluding curative surgery, rising global incidence, and a poor prognosis. Chemotherapy is the mainstay of the current treatment, which results in a median overall survival of less than one year, underscoring the need for novel therapeutic agents and strategies. Next-generation sequencing-based molecular profiling has shed light on the underpinnings of the complex pathophysiology of BTC and has uncovered numerous actionable targets, leading to the discovery of new therapies tailored to the molecular targets. Therapies targeting fibroblast growth factor receptor (FGFR) fusion, isocitrate dehydrogenase (IDH) mutations, the human epidermal growth factor receptor (HER) family, DNA damage repair (DDR) pathways, and BRAF mutations have produced early encouraging results in selected patients. Current clinical trials evaluating targeted therapies, as monotherapies and in combination with other agents, are paving the way for novel treatment options. Genomic profiling of cell-free circulating tumor DNA that can assist in the identification of an actionable target is another exciting area of development. In this review, we provide a contemporaneous appraisal of the evolving targeted therapies and the ongoing clinical trials that will likely transform the therapeutic paradigm of BTC.

Bolus 5-fluorouracil (5-FU) In Combination With Oxaliplatin Is Safe and Well Tolerated in Patients Who Experienced Coronary Vasospasm With Infusional 5-FU or Capecitabine

INTRODUCTION

Coronary vasospasm associated with fluoropyrimidine (FP)-based chemotherapy is a potentially serious complication and reported to occur more often with infusional 5-fluorouracil (5-FU) or capecitabine than with bolus 5-FU. Given the additional benefit of oxaliplatin over FP alone in the management of colorectal cancer, retaining oxaliplatin in the treatment regimen is desirable, but the safety of combining bolus 5-FU with oxaliplatin in patients with FP-induced vasospasm is not well established. We performed a retrospective review to explore the safety of substituting FLOX (bolus 5-FU, oxaliplatin, leucovorin) for FOLFOX (infusional 5-FU, oxaliplatin, leucovorin) and CAPOX (capecitabine, oxaliplatin) in patients who had FP-induced coronary vasospasm.

PATIENTS AND METHODS

The pharmacy database of Mayo Clinic was queried to identify patients who developed coronary vasospasm associated with FOLFOX or CAPOX between January 2011 and January 2018 and were subsequently treated with FLOX. Detailed information was obtained on these patients by retrospective electronic chart review.

RESULTS

A total of 10 patients (median age, 56.5 years; range, 36-77 years) were identified, 9 with FOLFOX and 1 with CAPOX. Among the patients treated with FOLFOX, 8 patients had chest pain as the presenting complaint that had started within 48 hours of beginning of the 5-FU infusion. In 9 of 10 patients, coronary vasospasm occurred with the first cycle of therapy. All patients made full recovery after discontinuation of infusional 5-FU or capecitabine. All patients subsequently received FLOX with 7 median bolus 5-FU doses (range, 2-22 doses) and 7 median oxaliplatin doses (range, 2-12 doses) at 7 days to 18 months after the event, with 7 patients treated within 4 weeks of the event. FLOX did not cause any cardiovascular adverse events in any of the 10 patients.

CONCLUSION

Bolus 5-FU in combination with oxaliplatin is safe in patients who have experienced coronary vasospasm with infusional 5-FU or capecitabine.

Clinicopathological features and outcomes of fibrolamellar hepatocellular carcinoma

BACKGROUND

Clinicopathological features and the outcomes of patients with fibrolamellar hepatocellular carcinoma (FLHCC) are not clearly defined.

METHODS

Data were collected by retrospective chart review on 42 patients with FLHCC treated between 1990 and 2017 at Mayo Clinic.

RESULTS

Of 42 patients (median age at diagnosis 22 years), 10 patients (23.8%) had stage I disease and 32 patients (76.2%) had stage II to IVB disease. All 10 patients with stage I disease and 21 of 32 patients with stage II-IVB disease underwent resection at presentation. In stage I patient group, 6 patients experienced recurrence with a median time to recurrence of 30.5 months and a 5-year overall survival (OS) of 86%. Patients with stage II to IVB disease who underwent resection (n=21) upfront had a median OS of 32.5 months and 5-year OS of 44%. In the upfront surgery group, 71% of patients experienced recurrence. The median OS of patients with unresectable disease (n=11) was 10 months. Four out of nine patients treated with sorafenib had stable disease and one patient with programmed cell death ligand-1 (PD-L1) expressing tumor had a near complete response after 2 months of therapy with nivolumab.

CONCLUSIONS

In FLHCC, surgical resection was associated with prolonged OS; although most patients had a disease recurrence regardless of disease stage and resection margin status. The response to kinase inhibitor, sorafenib, was variable. In select cases, therapy with a checkpoint inhibitor may provide a viable treatment option.

The Promise of Circulating Tumor DNA (ctDNA) in the Management of Early-Stage Colon Cancer: A Critical Review

The current standard treatment for patients with early-stage colon cancer consists of surgical resection, followed by adjuvant therapy in a select group of patients deemed at risk of cancer recurrence. The decision to administer adjuvant therapy, intended to eradicate the clinically inapparent minimal residual disease (MRD) to achieve a cure, is guided by clinicopathologic characteristics of the tumor. However, the risk stratification based on clinicopathologic characteristics is imprecise and results in under or overtreatment in a substantial number of patients. Emerging research indicates that the circulating tumor DNA (ctDNA), a fraction of cell-free DNA (cfDNA) in the bloodstream that originates from the neoplastic cells and carry tumor-specific genomic alterations, is a promising surrogate marker of MRD. Several recent studies suggest that ctDNA-guided risk stratification for adjuvant therapy outperforms existing clinicopathologic prognostic indicators. Preliminary data also indicate that, aside from being a prognostic indicator, ctDNA can inform on the efficacy of adjuvant therapy, which is the underlying scientific rationale for several ongoing clinical trials evaluating ctDNA-guided therapy escalation or de-escalation. Furthermore, serial monitoring of ctDNA after completion of definitive therapy can potentially detect cancer recurrence much earlier than conventional surveillance methods that may provide a critical window of opportunity for additional curative-intent therapeutic interventions. This article presents a critical overview of published studies that evaluated the clinical utility of ctDNA in the management of patients with early-stage colon cancer, and discusses the potential of ctDNA to transform the adjuvant therapy strategies.

Prognostic variables in low and high risk stage III colon cancers treated in two adjuvant chemotherapy trials

BACKGROUND

Stratification of patients with stage III colon cancer into low (T1-3N1) and high (T4 and/or N2) risk groups is used to guide the duration of adjuvant chemotherapy. We determined the relative contribution of clinical and molecular features to survival by risk group.

MATERIALS & METHODS

Stage III colon cancer (N = 5337) patients from two adjuvant trials of FOLFOX ± cetuximab [N0147 (Alliance), PETACC-8] were risk grouped, then subgrouped by clinical features and molecular variables [KRAS and BRAF/mismatch repair (MMR) combined variable]. Distributions of disease-free survival (DFS), overall survival (OS), and survival after recurrence (SAR) were estimated. In multivariable Cox models, backward elimination was performed for analysis of candidate predictors of outcomes. Relative contributions of model-selected variables to outcomes by risk group were calculated using χ2.

RESULTS

Among low risk tumours, mutant KRAS and male gender were significantly associated with poorer OS multivariately. In high risk tumours, significantly poorer OS was observed for right sidedness and for mutant KRAS and BRAFV600E/pMMR, subgroups. Specifically, BRAFV600E/pMMR (OS: HR = 1.75; 95% CI: 1.36-2.24; Padj<.0001) and right- versus left-sidedness were associated with significantly poorer DFS, OS (HR = 1.56; 95% CI: 1.31-1.83; Padj<.0001), and SAR (HR = 1.64; 95% CI: 1.37-1.95; Padj<.0001). Poor prognosis of mutant KRAS for DFS and OS was similar among risk groups. BRAF/MMR and sidedness were associated with poorer SAR in both low and high risk tumours. Age, gender, and KRAS were the top three relative contributors to DFS and OS among low risk tumours; sidedness ranked first for DFS and OS, and second to BRAF/MMR for SAR among high risk tumours.

CONCLUSION

Sidedness and BRAF/MMR contributed the most to survival outcomes among high risk tumours and should be interpreted in the context of risk group.

Outcomes on anti-VEGFR-2/paclitaxel treatment after progression on immune checkpoint inhibition in patients with metastatic gastroesophageal adenocarcinoma

Through our involvement in KEYNOTE-059, we unexpectedly observed durable responses in two patients with metastatic gastroesophageal adenocarcinoma (mGEA) who received ramucirumab (anti-VEGFR-2)/paclitaxel after immune checkpoint inhibition (ICI). To assess the reproducibility of this observation, we piloted an approach to administer ramucirumab/paclitaxel after ICI in more patients, and explored changes in the immune microenvironment. Nineteen consecutive patients with mGEA received ICI followed by ramucirumab/paclitaxel. Most (95%) did not respond to ICI, yet after irRECIST-defined progression on ICI, all patients experienced tumor size reduction on ramucirumab/paclitaxel. The objective response rate (ORR) and progression-free survival (PFS) on ramucirumab/paclitaxel after ICI were higher than on the last chemotherapy before ICI in the same group of patients (ORR, 58.8% vs 11.8%; PFS 12.2 vs 3.0 months; respectively). Paired tumor biopsies examined by imaging mass cytometry showed a median 5.5-fold (range 4-121) lower frequency of immunosuppressive forkhead box P3+ regulatory T cells with relatively preserved CD8+ T cells, post-treatment versus pre-treatment (n = 5 pairs). We then compared the outcomes of these 19 patients with a separate group who received ramucirumab/paclitaxel without preceding ICI (n = 68). Median overall survival on ramucirumab/paclitaxel was longer with (vs without) immediately preceding ICI (14.8 vs 7.4 months) including after multivariate analysis, as was PFS. In our small clinical series, outcomes appeared improved on anti-VEGFR-2/paclitaxel treatment when preceded by ICI, in association with alterations in the immune microenvironment. However, further investigation is needed to determine the generalizability of these data. Prospective clinical trials to evaluate sequential treatment with ICI followed by anti-VEGF(R)/taxane are underway.

Local excision for patients with stage I anal canal squamous cell carcinoma can be curative

BACKGROUND

Definitive concurrent chemoradiation is the current standard of care for all stage I anal canal squamous cell carcinoma. Local excision as primary treatment for selected stage I lesions has been reported in the literature but is not currently recommended by major guidelines. We herein compared the oncologic outcomes of patients with stage I anal canal squamous cell carcinoma treated with local excision alone versus chemoradiation to determine if there are any significant differences in outcomes including disease free survival, overall survival (OS) and local failure rate.

METHODS

A retrospective review of all patients treated for stage I anal canal squamous cell carcinoma between 1990 and 2016 was conducted. Data collected included baseline demographics, staging studies, pathology, treatment received, relapse pattern and survival.

RESULTS

A total of 57 patients were treated for stage I anal canal squamous cell carcinoma between 1990 and 2016; 13 were treated with local excision alone and 44 were treated with chemoradiation therapy. Baseline characteristics in both cohorts of patients were comparable. Median follow-up duration of the local excision and the chemoradiation cohorts were 106 and 70 months, respectively. Of the 13 patients in local excision cohort, two patients had disease recurrence, at 21 and 97 months from the diagnosis. Both patients were long term survivors with salvage treatment. In chemoradiation cohort, 1 out of 44 patients had a local recurrence at 1 year who underwent curative resection. Five-year progression free survival (PFS) of subjects in local excision cohort and chemoradiation cohort were 91% and 83%, respectively (P=0.57).

CONCLUSIONS

Local excision as primary treatment may be safe and effective for a selected group of stage I anal canal squamous cell carcinoma patients.

Efficacy of Immune Checkpoint Inhibition and Cytotoxic Chemotherapy in Mismatch Repair-Deficient and Microsatellite Instability-High Pancreatic Cancer: Mayo Clinic Experience

PURPOSE

Pancreatic cancer (PC) carries a poor prognosis with high rates of unresectable/metastatic disease at diagnosis, recurrence after resection, and few systemic therapy options. Deficient mismatch repair (dMMR)/high microsatellite instability (MSI-H) PCs demonstrated uncharacteristically poor outcomes in KEYNOTE-158, evaluating pembrolizumab in MSI-H solid tumors. Our study aggregates the Mayo Clinic experience with dMMR/MSI-H PCs, characterizing the clinical, molecular, and treatment response patterns with a focus on response to immune checkpoint inhibitors (ICIs).

METHODS

Retrospective data were collected from the electronic medical record from December 2009 to February 2023. Patients were included if they had a pathologically confirmed pancreatic malignancy and had (1) deficient expression of mismatch repair (MMR) proteins by tumor immunohistochemistry, (2) pathogenic mutation of MMR genes on genomic sequencing, and/or (3) MSI-H by polymerase chain reaction.

RESULTS

Thirty-two patients were identified for inclusion, with all stages of disease represented. Sixteen of these patients underwent surgery or chemoradiotherapy. Of these patients, uncharacteristically favorable responses were seen, with a recurrence rate of only 19% (n = 3) despite a median follow-up of 25 months. In the palliative setting, excellent responses to ICI were seen, with overall response rate (ORR) of 75% (20% complete response). Median time to disease progression was not reached. Response rates to cytotoxic chemotherapy in the palliative setting were poor, with 30% ORR and median time to progression of 4 months. We observed a high rate of discrepancy between MMR and MSI testing methods, representing 19% of the entire cohort and 26% of evaluable cases.

CONCLUSION

Our data argue for the preferential use of ICI over cytotoxic chemotherapy in any patient with dMMR/MSI-H PC requiring systemic therapy, including in the metastatic and adjuvant/neoadjuvant settings.

BESPOKE IO protocol: a multicentre, prospective observational study evaluating the utility of ctDNA in guiding immunotherapy in patients with advanced solid tumours

INTRODUCTION

Immunotherapy (IO) has transformed the treatment paradigm for a wide variety of solid tumours. However, assessment of response can be challenging with conventional radiological imaging (eg, iRECIST), which do not precisely capture the unique response patterns of tumours treated with IO. Emerging data suggest that circulating tumour DNA (ctDNA) can aid in response assessment in patients with solid tumours receiving IO. The short half-life of ctDNA puts it in a unique position for early treatment response monitoring. The BESPOKE IO study is designed to investigate the clinical utility of serial ctDNA testing to assess treatment response using a tumour-informed, bespoke ctDNA assay (Signatera) and to determine its impact on clinical decision-making with respect to continuation/discontinuation, or escalation/de-escalation of immunotherapy in patients with advanced solid tumours.

METHODS AND ANALYSIS

The BESPOKE IO is a multicentre, prospective, observational study with a goal to enroll over 1500 patients with solid tumours receiving IO in up to 100 US sites. Patients will be followed for up to 2 years with serial ctDNA analysis, timed with every other treatment cycle. The primary endpoint is to determine the percentage of patients who will have their treatment regimen changed as guided by post-treatment bespoke ctDNA results along with standard response assessment tools. The major secondary endpoints include progression-free survival, overall survival and overall response rate based on the ctDNA dynamics.

ETHICS AND DISSEMINATION

The BESPOKE IO study was approved by the WCG Institutional Review Board (Natera-20-043-NCP BESPOKE Study of ctDNA Guided Immunotherapy (BESPOKE IO)) on 22 February 2021. Data protection and privacy regulations will be strictly observed in the capturing, forwarding, processing and storing patients' data. Natera will approve the publication of any study results in accordance with the site-specific contract.

TRIAL REGISTRATION NUMBER

NCT04761783.

Phase II Trial of Trifluridine/Tipiracil in Patients with Advanced, Refractory Biliary Tract Carcinoma

LESSONS LEARNED

Trifluridine/tipiracil (FTD/TPI) shows promising antitumor activity in heavily pretreated patients with advanced biliary tract carcinoma, including patients with 5-fluorouracil refractory tumors. FTD/TPI has an acceptable safety profile and should be studied further in patients with advanced biliary tract carcinoma after progression on standard first-line therapy.

BACKGROUND

Patients with advanced biliary tract carcinoma (BTC) refractory to first-line therapy lack an established second-line option. Trifluridine/tipiracil (FTD/TPI) has activity in both fluoropyrimidine-sensitive and -resistant tumors, which led us to conduct a single arm phase II trial to evaluate the safety and efficacy of FTD/TPI for patients previously treated for advanced BTC.

METHODS

Patients with advanced BTC previously treated with at least one line of chemotherapy were enrolled and treated with FTD/TPI until disease progression or unacceptable toxicity. The primary endpoint target was to have at least 6 patients who were progression free and alive at 16 weeks among 25 evaluable patients. Secondary endpoints included overall survival (OS), overall response rate (ORR), progression-free survival (PFS), and toxicity.

RESULTS

Of 27 evaluable patients, 59.3% received at least three prior lines of therapy, and 81.5% had previous exposure to fluoropyrimidine. Eight (32%, 95% confidence interval [CI], 14.9%-53.5%) patients were progression free at 16 weeks in the primary analysis population (n = 25), which met the predefined efficacy criteria. Median PFS and OS were 3.8 (95% CI, 2-5.8 months) and 6.1 (95% CI, 4.4-11.4 months) months, respectively. No objective responses were seen. There were no unexpected safety signals noted.

CONCLUSION

FTD/TPI demonstrated promising antitumor activity, with acceptable toxicity, in heavily pretreated patients with advanced BTC.

First Report of Dramatic Tumor Responses with Ramucirumab and Paclitaxel After Progression on Pembrolizumab in Two Cases of Metastatic Gastroesophageal Adenocarcinoma

Checkpoint inhibitors targeted at programmed cell death-1 receptor (PD-1) and its ligand (PD-L1) can result in significant benefit to a small proportion of patients with cancer, including those with tumors of the stomach and gastroesophageal junction. These drugs are now approved for several solid tumors, including the recent accelerated approval of pembrolizumab for gastroesophageal adenocarcinomas in the third-line setting and beyond based on the KEYNOTE-059 phase II trial. Data are lacking on the efficacy of chemotherapy after progression on PD-1 blockade in metastatic gastroesophageal adenocarcinoma. This report describes the exceptional response of two patients who received ramucirumab plus paclitaxel after progressive disease on pembrolizumab. This early clinical observation suggests that the sequence of administration of PD-1 blockade and chemotherapy may be important in this disease.

Finding Waldo: The Evolving Paradigm of Circulating Tumor DNA (ctDNA)-Guided Minimal Residual Disease (MRD) Assessment in Colorectal Cancer (CRC)

Circulating tumor DNA (ctDNA), the tumor-derived cell-free DNA fragments in the bloodstream carrying tumor-specific genetic and epigenetic alterations, represents an emerging novel tool for minimal residual disease (MRD) assessment in patients with resected colorectal cancer (CRC). For many decades, precise risk-stratification following curative-intent colorectal surgery has remained an enduring challenge. The current risk stratification strategy relies on clinicopathologic characteristics of the tumors that lacks precision and results in over-and undertreatment in a significant proportion of patients. Consequently, a biomarker that can reliably identify patients harboring MRD would be of critical importance in refining patient selection for adjuvant therapy. Several prospective cohort studies have provided compelling data suggesting that ctDNA could be a robust biomarker for MRD that outperforms all existing clinicopathologic criteria. Numerous clinical trials are currently underway to validate the ctDNA-guided MRD assessment and adjuvant treatment strategies. Once validated, the ctDNA technology will likely transform the adjuvant therapy paradigm of colorectal cancer, supporting ctDNA-guided treatment escalation and de-escalation. The current article presents a comprehensive overview of the published studies supporting the utility of ctDNA for MRD assessment in patients with CRC. We also discuss ongoing ctDNA-guided adjuvant clinical trials that will likely shape future adjuvant therapy strategies for patients with CRC.

Systemic Therapy of Metastatic Pancreatic Adenocarcinoma: Current Status, Challenges, and Opportunities

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by nonspecific presenting symptoms, lack of a screening test, rapidly progressive clinical course, and presentation with an advanced-stage disease in the majority of patients. PDAC is essentially a systemic disease irrespective of the initial stage, as most patients with non-metastatic PDAC undergoing curative-intent treatment eventually experience metastatic relapse. Currently, cytotoxic chemotherapy remains the cornerstone of treatment in patients with advanced disease. However, the current standard treatment with multiagent chemotherapy has modest efficacy and results in median overall survival (OS) of less than a year and a 5-year OS of about 10%. The pathobiology of PDAC poses many challenges, including a unique tumor microenvironment interfering with drug delivery, intratumoral heterogeneity, and a strongly immunosuppressive microenvironment that supports cancer growth. Recent research is exploring a wide range of novel therapeutic targets, including genomic alterations, tumor microenvironment, and tumor metabolism. The rapid evolution of tumor genome sequencing technologies paves the way for personalized, targeted therapies. The present review summarizes the current chemotherapeutic treatment paradigm of advanced PDAC and discusses the evolving novel targets that are being investigated in a myriad of clinical trials.

TAS-102: A resurrected novel Fluoropyrimidine with expanding role in the treatment of gastrointestinal malignancies

TAS-102 is an orally administered fixed-dose formulation consisting of trifluorothymidine (TFT), a fluoropyrimidine antimetabolite, and tipiracil (TPI), an inhibitor of thymidine phosphorylase (TP) that prevents rapid degradation of TFT and ensures its bioavailability. The novelty of TAS-102 lies in its antitumor activity against 5-fluorouracil (5-FU) resistant tumors, demonstrated both in the in vitro models and xenografts. The cytotoxic activity of TFT relies primarily on extensive incorporation of the TFT metabolite into the cellular DNA inducing DNA dysfunction and cell death. In contrast, 5-fluorouracil (5-FU) interferes with DNA biosynthesis by inhibiting thymidylate synthase(TS), which partly explains the absence of cross-resistance between TAS-102 and 5-FU. TAS-102 is currently approved in the third-line setting for patients with metastatic colorectal and gastric cancer based on phase III randomized clinical trial data confirming an overall survival benefit with TAS-102. The preliminary data from recently reported studies suggest a potential expanding role of TAS-102 in a variety of gastrointestinal (GI) cancers. The current article presents an overview of the pharmacology, clinical development of TAS-102, and its emerging role in the treatment of GI cancers. In addition, we discussed the rationale underlying the ongoing clinical trials investigating various combinations of TAS-102 with other anticancer agents, including targeted therapies, in a wide range of GI tumors.

Tumor Mutational Burden in Real-World Patients With Pancreatic Cancer: Genomic Alterations and Predictive Value for Immune Checkpoint Inhibitor Effectiveness

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is largely considered a nonimmunogenic malignancy; however, approximately 1%, of patients may have tumors with deficient mismatch repair, high microsatellite instability, or high tumor mutational burden (TMB ≥10 mutations/Mb), which may be predictive of response to immune checkpoint inhibitor (ICI) therapy. We sought to analyze outcomes of patients with high-TMB and pathogenic genomic alterations observed in this population.

METHODS

This study included patients with PDAC who underwent comprehensive genomic profiling (CGP) at Foundation Medicine (Cambridge, MA). Clinical data were obtained from a US-wide real-world clinicogenomic pancreatic database. We report genomic alterations in those with high and low TMB, and compare outcomes on the basis of receipt of single-agent ICI or therapy regimens not containing ICI.

RESULTS

We evaluated 21,932 patients with PDAC who had tissue CGP data available, including 21,639 (98.7%) with low-TMB and 293 (1.3%) with high-TMB. Among patients with high-TMB, a greater number of alterations were observed in BRCA2, BRAF, PALB2, and genes of the mismatch repair pathway, whereas fewer alterations were observed in KRAS. Among patients who received an ICI (n = 51), those with high-TMB had more favorable median overall survival when compared with the low-TMB subset (25.7 v 5.2 months; hazard ratio, 0.32; 95% CI, 0.11 to 0.91; P = .034).

CONCLUSION

Longer survival was observed in patients with high-TMB receiving ICI compared with those with low-TMB. This supports the role of high-TMB as a predictive biomarker for efficacy of ICI therapy in PDAC. Additionally, we report higher rates of BRAF and BRCA2 mutations and lower rates of KRAS mutation among patients with PDAC and high-TMB, which to our knowledge, is a novel finding.

Fibroblast growth factor receptor (FGFR) inhibitors in cholangiocarcinoma: current status, insight on resistance mechanisms and toxicity management

INTRODUCTION

Cholangiocarcinoma (CCA) frequently presents with an advanced disease precluding curative surgery and shows modest response to chemotherapy. Advancements in genomic profiling have unfolded critical pathophysiologic underpinnings of CCA, leading to the development of targeted therapies with encouraging early results. Of the targetable genomic alterations, fibroblast growth factor receptor-2 (FGFR-2) fusions or rearrangements are present in 10-15% of patients with intrahepatic CCA. Clinical trials demonstrating significant antitumor activity of FGFR inhibitors in FGFR-2 fusion or rearrangement enriched chemotherapy-refractory patients led to FDA approval of FGFR inhibitors, pemigatinib and infigratinib, in the second-line setting. We identified peer-reviewed articles on FGFR inhibitors utilizing the PubMed database published between 2015 and 2021.

AREAS COVERED

This article provides an overview of clinical and biological characteristics of FGFR-driven CCA, pharmacology and antitumor activity of currently available FGFR inhibitors, and the evolving knowledge of drug resistance mechanisms. Additionally, toxicities associated with FGFR inhibitor use and their management have been described.

EXPERT OPINION

The development of FGFR inhibitors is a significant advancement in the therapeutic paradigm of advanced CCA. Ongoing research utilizing FGFR inhibitors in treatment-naïve patients, elucidation of resistance mechanisms to harness future trials, and exploration of combination strategies will transform the treatment landscape of CCA.

Impact of perioperative chemotherapy on survival in patients with cholangiocarcinoma undergoing curative resection

BACKGROUND

Most patients with localized cholangiocarcinoma (CCA) endure cancer relapse after curative resection underscoring the importance of systemic therapy. The current study attempts to determine the impact of perioperative chemotherapy (PC) on survival in patients with CCA undergoing resection.

METHODS

Patients diagnosed with CCA undergoing curative-intent resection between January 1, 2000, and December 31, 2019, in a tertiary care center were included. Cox proportional hazard modeling was used to determine the impact of PC on disease-free survival (DFS) and overall survival (OS). In addition, a nomogram was constructed to estimate 3-year DFS.

RESULTS

Among the 182 patients included in the analysis, 102 underwent surgery alone, and 80 received surgery plus PC. Forty-two patients received neoadjuvant therapy, and 38 patients received adjuvant therapy. On multivariate analysis, PC was significantly associated with an improved DFS (HR, 95% CI: 0.63, 0.41-0.98; p = 0.04) and OS (HR, 95% CI: 0.46, 0.27-0.78; p < 0.01). In the interaction analysis, the survival benefit was especially seen in patients with positive resection margins and tumor size > 5 cm.

CONCLUSION

In patients with CCA undergoing curative resection, receipt of PC was associated with improved DFS and OS. The nomogram constructed from this database provides an estimate of 3-year DFS after surgical resection. Randomized trials are needed to define the optimal regimen and sequence.

Outcome of Patients With Early-Stage Mismatch Repair Deficient Colorectal Cancer Receiving Neoadjuvant Immunotherapy: A Systematic Review

PURPOSE

We conducted a systematic review to evaluate the outcome of patients with early-stage (stages I-III) mismatch repair deficient (dMMR) colorectal cancer (CRC) receiving neoadjuvant immunotherapy (NIT) with immune checkpoint inhibitor (ICI)-based regimens.

METHODS

MEDLINE, Scopus, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched for publications reporting the outcome of patients with early-stage dMMR CRC receiving NIT. The primary outcome measures were the complete response (CR) rate (clinical CR [cCR] or pathologic CR [pCR]) and the incidence of grade 3 or higher toxicities.

RESULTS

The search identified 37 publications that included 423 patients with colon (n = 326, 77%) and rectal (n = 97,23%) cancers aged 19-82 years; most patients had stage III CRC (88%). Approximately 67% of patients received monotherapy with anti-PD-1 agents; the rest received dual ICIs (ipilimumab plus nivolumab). The CR rate (pCR + cCR) in the overall population was 72% (305 of 423). The R0 resection and pCR rates were 99.3% and 70% among the patients undergoing surgery, respectively. Only four (0.9%) patients had primary resistance to NIT. After median follow-up periods ranging from 4 to 27 months, 3 (0.7%) patients progressed after an initial response. Grade 3 or higher toxicities were uncommon (6.3%), rarely delaying planned surgery.

CONCLUSION

NIT in patients with early-stage dMMR CRC is associated with a high response rate, low primary resistance to immunotherapy and cancer recurrence rate, and an excellent safety profile. The findings of the present systematic review support further investigation of NIT in patients with early-stage dMMR CRC, with a particular emphasis on the organ-preserving potential of this strategy.

A glimpse into the future of esophageal carcinoma in the United States: predicting the future incidence until 2040 based on the current epidemiological data

BACKGROUND

Esophageal carcinoma is the sixth most common cause of death worldwide. With the changing paradigm of esophageal carcinoma, we sought to estimate the future burden of esophageal carcinoma by histology, age, sex, and race, which could help plan prevention, control, and treatment strategies for this cancer.

METHODS

Surveillance, Epidemiology, and End Results (SEER) 14 registries were utilized to obtain incidence data from 2000 to 2016. We applied age-period-cohort models to estimate future esophageal carcinoma incidence rates and the estimated disease burden by multiplying incidence forecasts by corresponding US Census population projections.

RESULTS

Our forecasting study suggests that the incidence (per 100,000 persons) of esophageal adenocarcinoma for the age group 40-65 years will increase from 2.12 in 2021 to 3.86 in 2040, which corresponds to an 82% increase over the course of 19 years (3.2% per year, 95% CI: -2.3% to 9.1%). In addition, we found a considerable decrease in the incidence of esophageal squamous cell carcinoma in the current age groups 40-65 years (-2.7% per year) and >65 years (-4.6% per year).

CONCLUSIONS

Preventive efforts of esophageal adenocarcinoma should primarily target males of age up to 65 years and females of current age 40 to 65 years who will make up the older age group (>65 years) in 2040.

Evolution of Systemic Therapy in Metastatic Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma is characterized by early systemic dissemination, a complex tumor microenvironment, as well as significant intratumoral and intertumoral heterogeneity. Treatment options and survival in pancreatic ductal adenocarcinoma have improved steadily over the last 3 decades. Although cytotoxic chemotherapy is currently the mainstay of treatment for pancreatic ductal adenocarcinoma, evolving therapeutic strategies are aimed at targeting the tumor microenvironment, metabolism, and the tumor-host immune balance.

Circulating Tumor DNA as a Minimal Residual Disease Assessment and Recurrence Risk in Patients Undergoing Curative-Intent Resection with or without Adjuvant Chemotherapy in Colorectal Cancer: A Systematic Review and Meta-Analysis

Emerging data have suggested that circulating tumor DNA (ctDNA) can be a reliable biomarker for minimal residual disease (MRD) in CRC patients. Recent studies have shown that the ability to detect MRD using ctDNA assay after curative-intent surgery will change how to assess the recurrence risk and patient selection for adjuvant chemotherapy. We performed a meta-analysis of post-operative ctDNA in stage I-IV (oligometastatic) CRC patients after curative-intent resection. We included 23 studies representing 3568 patients with evaluable ctDNA in CRC patient post-curative-intent surgery. Data were extracted from each study to perform a meta-analysis using RevMan 5.4. software. Subsequent subgroup analysis was performed for stages I-III and oligometastatic stage IV CRC patients. Results showed that the pooled hazard ratio (HR) for recurrence-free survival (RFS) in post-surgical ctDNA-positive versus -negative patients in all stages was 7.27 (95% CI 5.49-9.62), p < 0.00001. Subgroup analysis revealed pooled HRs of 8.14 (95% CI 5.60-11.82) and 4.83 (95% CI 3.64-6.39) for stages I-III and IV CRC, respectively. The pooled HR for RFS in post-adjuvant chemotherapy ctDNA-positive versus -negative patients in all stages was 10.59 (95% CI 5.59-20.06), p < 0.00001. Circulating tumor DNA (ctDNA) analysis has revolutionized non-invasive cancer diagnostics and monitoring, with two primary forms of analysis emerging: tumor-informed techniques and tumor-agnostic or tumor-naive techniques. Tumor-informed methods involve the initial identification of somatic mutations in tumor tissue, followed by the targeted sequencing of plasma DNA using a personalized assay. In contrast, the tumor-agnostic approach performs ctDNA analysis without prior knowledge of the patient's tumor tissue molecular profile. This review highlights the distinctive features and implications of each approach. Tumor-informed techniques enable the precise monitoring of known tumor-specific mutations, leveraging the sensitivity and specificity of ctDNA detection. Conversely, the tumor-agnostic approach allows for a broader genetic and epigenetic analysis, potentially revealing novel alterations and enhancing our understanding of tumor heterogeneity. Both approaches have significant implications for personalized medicine and improved patient outcomes in the field of oncology. The subgroup analysis based on the ctDNA method showed pooled HRs of 8.66 (95% CI 6.38-11.75) and 3.76 (95% CI 2.58-5.48) for tumor-informed and tumor-agnostic, respectively. Our analysis emphasizes that post-operative ctDNA is a strong prognostic marker of RFS. Based on our results, ctDNA can be a significant and independent predictor of RFS. This real-time assessment of treatment benefits using ctDNA can be used as a surrogate endpoint for the development of novel drugs in the adjuvant setting.

A Patient With Locally Advanced Mismatch-Repair-Deficient Pancreatic Ductal Adenocarcinoma Successfully Treated With Neoadjuvant Immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a dismal prognosis. Approximately 30% of patients present with locally advanced disease, defined as pancreatic tumor with invasion to adjacent structures, including the vasculatures that preclude an upfront surgical resection. Emerging data suggest that neoadjuvant therapy, typically consisting of systemic chemotherapy followed by concurrent chemoradiation, increases the likelihood of potentially curative R0 resection by downstaging the tumor and improves survival in patients with locally advanced PDAC. PDAC with deficient DNA mismatch repair (dMMR)/microsatellite instability-high molecular signature is exceedingly rare. The role of immunotherapy is emerging in various dMMR gastrointestinal tumors, both in the metastatic and neoadjuvant settings. However, the efficacy of immunotherapy in the neoadjuvant setting in patients with dMMR locally advanced PDAC remains unknown. Herein, we describe a patient who presented with unresectable dMMR locally advanced PDAC and underwent neoadjuvant immunotherapy with pembrolizumab that resulted in a remarkable reduction of the tumor size, rendering the tumor resectable. Furthermore, the presence of dMMR signature in the tumor was detected by circulating tumor DNA analysis. This is the first report, to our knowledge, of the successful use of neoadjuvant immunotherapy in a patient with locally advanced PDAC.