Maintenance Treatment for Metastatic Pancreatic Cancer: Balancing Therapeutic Intensity with Tolerable Toxicity.

Metastatic pancreatic ductal adenocarcinoma is typically treated with multi-agent chemotherapy until disease progression or intolerable cumulative toxicity. For patients whose disease shows ongoing control or response beyond a certain timeframe (≥3-4 months), options include pausing chemotherapy with close monitoring or de-escalating to maintenance therapy with the goal of prolonging progression-free and overall survival while preserving quality of life. There is currently no universally accepted standard of care and a relative dearth of randomized clinical trials in the maintenance setting. Conceptually, such therapy can entail continuing the least toxic components of a first-line regimen and/or introducing novel agent(s) such as the poly(ADP-ribose) polymerase inhibitor olaparib, which is presently the only approved drug for maintenance treatment and is limited to a genetically defined subset of patients. In addition to identifying new therapeutic candidates and combinations in the maintenance setting, including targeted agents and immunotherapies, future research should focus on better understanding this unique biologic niche and how treatment in the maintenance setting may be distinct from resistant/refractory disease; identifying molecular predictors for more effective pairing of specific treatments with patients most likely to benefit; and establishing patient-reported outcomes in clinical trials to ensure accurate capture of quality of life metrics.

The Additional Diagnostic Benefit of Pancreatic Cancer Molecular Profiling After Germline Testing.

OBJECTIVES: Germline genetic testing is universally recommended for patients with pancreatic cancer to guide therapeutic selection, but tumor molecular profiling (TMP) is not. We aimed to determine the real-world additional diagnostic benefit of TMP after germline testing for detecting therapeutically actionable alterations. METHODS: Medical records and genetic test reports were reviewed for all patients who underwent germline testing and TMP at the University of California San Francisco during January 2016-January 2020. The detection rate of actionable alterations with germline testing alone was compared to that with both germline testing and TMP. RESULTS: Among 738 eligible patients, 144 (20%) met study criteria. Germline testing detected 10 actionable alterations in 10 patients. Tumor molecular profiling identified 3 new therapeutic targets among these 10 patients and 45 targets in 41 additional patients, increasing the number of patients with actionable findings from 10 (7%) to 51 (35%). Most actionable alterations (35/58, 60%) involved genes associated with the Homologous Recombination DNA Damage Repair pathway. CONCLUSIONS: Tumor molecular profiling after germline testing increased the detection of actionable alterations by 5-fold. Tumor molecular profiling is a necessary complement to germline genetic testing to fully inform therapeutic decision making for all patients with pancreatic cancer.

The Gut Microbiome in Colorectal Cancer.

The gut microbiome is important in human health and disease. Recent studies have begun to elucidate its specific role in colorectal cancer. The gut microbiome seems to play an integral role in colorectal cancer initiation and progression, and oncologic drug metabolism and toxicity. This review examines the associations between the gut microbiome and colorectal cancer initiation, progression, and oncologic drug metabolism, highlighting proposed mechanisms and landmark publications in this field. It also discusses potential methods of modulating the gut microbiome, underscoring the gaps in current understanding, and ends with a clinically relevant overview of microbiome research considerations and study design.

Implementation of an Embedded In-Clinic Genetic Testing Station to Optimize Germline Testing for Patients with Pancreatic Adenocarcinoma.

BACKGROUND: Germline genetic testing is universally recommended for patients with pancreatic cancer, but testing remains infrequent. In May 2018, we implemented a systematic patient intake workflow featuring an in-clinic genetic testing station (GTS) at the University of California San Francisco (UCSF) to expedite genetic counseling and facilitate sample collection. We sought to determine the impact of this innovation on rates of genetic counseling and testing. METHODS: Medical records, patient intake records, and genetic test reports were retrospectively reviewed for new patients with pancreatic cancer eligible for germline testing at UCSF from May 2018 to May 2019. Primary outcomes included the rate of offered genetic counseling and confirmed germline testing. Data were compared for periods before and after GTS implementation. Associations between demographic characteristics and testing rates were assessed. RESULTS: Genetic counseling/testing was offered to 209 (94%) of 223 eligible patients, and 158 (71%) completed testing (135 at UCSF, 23 elsewhere). Compared with a traditional referral-based genetic counseling model, confirmed testing increased from 19% to 71%, patient attrition between referral and genetics appointment decreased from 36% to 3%, and rate of pathogenic variant detection increased from 20% to 33%. Patients who were younger, identified as non-Hispanic White, and spoke English as a primary language were more likely to complete testing. CONCLUSIONS: Implementation of a systematic patient intake workflow and in-clinic GTS resulted in the highest reported real-world rate of germline testing for patients with pancreatic cancer. Health care disparities were identified and will guide future innovation. This report provides a model for other centers to create a similar testing infrastructure. IMPLICATIONS FOR PRACTICE: This study demonstrates that a systematic patient intake workflow and associated in-clinic genetic testing station improve delivery of genetic counseling and completion of germline testing for patients with pancreatic cancer. This study achieved, to the authors' knowledge, the highest real-world rate of confirmed genetic testing in this patient population. This article describes this innovation in detail to guide replication at other medical centers and facilitate guideline-concordant care for patients with pancreatic cancer. This infrastructure can also be applied to other cancers for which germline testing is recommended.

Durable response after immune checkpoint inhibitor-related diabetes in mismatch repair-deficient pancreatic cancer.

Mismatch repair protein deficiency occurs in 0.8-2% of pancreatic ductal adenocarcinomas and confers susceptibility to immunotherapy. Herein, we report the case of a patient with Lynch syndrome-associated, locally advanced mismatch repair protein deficiency pancreatic ductal adenocarcinomas who demonstrated a sustained response to second-line treatment with pembrolizumab, but eventually developed immune-related diabetic ketoacidosis requiring discontinuation of treatment. He has since remained in remission, off treatment, over the following 3 years, with regular surveillance showing no clinical or radiographic evidence of disease progression. The patient's unusual disease course raises the question of whether this serious immune-related adverse event affecting the organ of malignant involvement may have predicted his remarkable and durable response.

Lay abstract A small subgroup of pancreatic cancers have mutations preventing effective repair of damaged DNA; a condition termed 'mismatch repair protein deficiency'. These tumors are often effectively treated with immunotherapy. Here we describe a patient whose mismatch repair protein deficiency pancreatic cancer responded well to pembrolizumab immunotherapy, but who later developed diabetes as an immunotherapy-related adverse effect. Treatment was stopped, but his tumor remained stable off treatment over the next 3 years. His unique clinical course raises the question of whether the development of diabetes, a pancreas-specific adverse effect, may have predicted the effective treatment of pancreatic cancer.

Anxious, Depressed, and Planning for the Future: Advance Care Planning in Diverse Older Adults.

OBJECTIVES: To determine whether depression and anxiety are associated with advance care planning (ACP) engagement or values concerning future medical care. DESIGN: Cross-sectional. PARTICIPANTS: English- and Spanish-speaking patients, aged 55 years and older, from a San Francisco, CA, county hospital. MEASURES: Depression was measured by the Patient Health Questionnaire 8-item scale, and anxiety was measured by the Generalized Anxiety Disorder 7-item scale, using standardized cutoffs of 10 or more for moderate-to-severe symptoms. ACP engagement was measured using validated surveys of ACP behavior change (e.g., self-efficacy and readiness; mean five-point Likert score) and ACP actions (e.g., ask, discuss, and document wishes; 0- to 25-point scale), with higher scores representing higher engagement. In addition, we asked a question about valuing life extension ("some health situations would make life not worth living"). We used adjusted linear and logistic regression. RESULTS: Mean age of 986 participants was 63 years, 81% were non-White, 39% had limited health literacy, 45% were Spanish speaking, 13% had depression, and 10% had anxiety. After adjustment for demographic and health status variables, participants who were depressed versus not depressed had higher ACP behavior change scores (0.2 points; 95% confidence interval (CI) = 0.06-0.38; P = .007), higher ACP action scores (1.5 points; 95% CI = 0.51-2.57; P = .003), and higher odds of not valuing life extension (odds ratio (OR) = 2.5; 95% CI = 1.5-4.3; P < .001). Results were similar in participants with versus without anxiety (ACP behavior change: 0.2 points; 95% CI = 0.05-0.40; P = .01; ACP action scores: 1.2 points; 95% CI = 0.14-2.32; P = .028; odds of not valuing life extension: OR = 2.3; 95% CI = 1.3-3.9; P = .004). CONCLUSION: Depression and anxiety were associated with greater ACP engagement and not valuing life extension. Although the direction of association between ACP engagement and values with anxiety and depression cannot be determined in this cross-sectional study, these conditions may influence ACP preferences. Future studies should assess whether changes in anxiety or depression affect ACP preferences over time.

Postoperative Exacerbation of Oxaliplatin-induced Neurotoxicity in Gastrointestinal Cancers: A Case Series.

BACKGROUND/AIM: Oxaliplatin-induced neurotoxicity (OIN) can be severe and dose-limiting with clinically significant symptoms that persist for years. Few published reports have described postoperative exacerbation of OIN and more longitudinal data are needed to better characterize the phenomenon. PATIENTS AND METHODS: We identified 13 patients diagnosed with colon (n=7), rectal (n=4) or pancreatic (n=2) cancer who experienced postoperative OIN exacerbation at our medical center. Charts were reviewed for demographic and clinical data regarding OIN. RESULTS: OIN exacerbation was documented 0.5-7.0 months after the first surgery following oxaliplatin exposure, with a median duration of 10.6 months (range=1.4-86.1 months). OIN exacerbation persisted in 3/13 patients at last follow-up, and improved to pre-operative levels in 6/13 patients (with complete resolution in 4/13) within a median of 3.6 months from initial exacerbation. CONCLUSION: Given the widespread use of oxaliplatin in neoadjuvant and first-line treatment for gastrointestinal cancers, further study is warranted to prospectively and systematically define risks for postoperative OIN exacerbation.

Referral frequency, attrition rate, and outcomes of germline testing in patients with pancreatic adenocarcinoma.

Hereditary predisposition is estimated to account for 10% of all pancreatic cancer cases. However, referral patterns and clinical workflow for germline testing in this disease differ significantly by institution, and many at-risk patients may not undergo appropriate counseling and testing. We undertook an analysis of patients diagnosed with pancreatic cancer (PDAC) who were referred to the Clinical Genetics program of a high-volume academic center over a 3-year period to assess referral frequency, evaluate the yield of germline testing in this selected patient cohort, and elucidate the reasons individuals did not undergo recommended germline testing. Medical records of patients with PDAC referred for genetic counseling between January 2015 and October 2017 were reviewed for demographic, medical/family history, and disease-specific data. If testing did not occur, reasons were documented. Genetic test results were categorized as negative, variants of unknown significance, or established pathogenic mutations. Descriptive statistics included means with standard deviations; associations were analyzed with t test and Fisher's exact test. 32% (137 of 432) of PDAC patients were referred for genetic counseling, but only 64% attended their appointment and 60% ultimately underwent germline testing. Common reasons for attrition included worsening disease severity, lack of patient follow-up, insurance concerns, and logistic/travel challenges. Pathogenic germline mutations were detected in 20% (16 of 82) of patients tested, distributed across races/ethnicities, and significantly associated with younger age and positive family history of breast cancer. PDAC patients frequently do not undergo genetic counseling/germline testing despite appropriate referrals, highlighting a need to develop streamlined processes to engage more patients in testing, especially those with high-risk features.

A Phase I Study of FOLFIRINOX Plus IPI-926, a Hedgehog Pathway Inhibitor, for Advanced Pancreatic Adenocarcinoma.

OBJECTIVES: In mouse models of pancreatic cancer, IPI-926, an oral Hedgehog inhibitor, increases chemotherapy delivery by depleting tumor-associated stroma. This multicenter phase Ib study evaluated IPI-926 in combination with FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, oxaliplatin) in patients with advanced pancreatic cancer. METHODS: Patients were treated with once-daily IPI-926 plus FOLFIRINOX. A 3 + 3 dose escalation design was used, with cohort expansion at the maximum tolerated dose. A subset of patients underwent perfusion computed tomography to assess changes in tumor perfusion. RESULTS: The maximum tolerated dose was identified 1 dose level below standard FOLFIRINOX. Common treatment-related adverse events included liver function test abnormalities, neuropathy, nausea/vomiting, and diarrhea. Objective response rate was high (67%), and patients receiving IPI-926 maintenance showed further declines in CA19-9 levels even after FOLFIRINOX discontinuation. Treatment did not result in consistent increases in tumor perfusion. The study closed early when a separate phase II trial of IPI-926 plus gemcitabine indicated detrimental effects of this combination. CONCLUSIONS: This is the first study to demonstrate the feasibility of using FOLFIRINOX as the chemotherapeutic backbone in a clinical trial design. Although robust antitumor activity and acceptable safety were observed with the addition of IPI-926 to this regimen, future development of Hedgehog inhibitors in pancreatic cancer seems unlikely.

Statin use and risk of pancreatic cancer: results from a large, clinic-based case-control study.

BACKGROUND: Statins are cholesterol-lowering medications with pleiotropic effects, including alterations in growth signaling, as well as immunomodulatory and anti-inflammatory effects that may alter cancer risk. Evidence from previous epidemiologic studies is inconsistent about whether statin use is associated with a reduced risk of pancreatic cancer (PC). METHODS: Patients with confirmed diagnoses of PC (cases) were recruited from medical and surgical oncology clinics, with controls (frequency-matched by sex and age) recruited from general medicine clinics, at a high-volume academic medical center over a 6-year period (2006-2011). Direct interviews were conducted with an epidemiological risk factor questionnaire covering topics such as medical history, lifestyle factors, and medication usage. Adjusted multivariable logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs) as estimates of the relative risk of PC. RESULTS: Data were obtained from 536 cases and 869 controls. Ever use of statins was associated with a 34% reduced PC risk (OR, 0.66; 95% CI, 0.47-0.92). In sex-stratified analyses, risk was statistically significantly reduced in men only (OR for men, 0.50; 95% CI, 0.32-0.79; OR for women, 0.86; 95% CI, 0.52-1.43). Duration of use was inversely associated with PC risk (>10-year use: overall OR, 0.51; OR for men, 0.41; 95% CI, 0.21-0.80; P(trend) = .006). CONCLUSIONS: This is the largest case-control study to demonstrate an inverse association between statin use and PC risk. Risk reduction in statin users appears to be sex-specific and is more pronounced in long-term users. Further research is warranted to better characterize this association and clarify the roles of underlying biologic mechanisms.

Metformin use among type 2 diabetics and risk of pancreatic cancer in a clinic-based case-control study.

A better understanding of the association between diabetes and pancreatic cancer (PC) may inform prevention and/or early detection strategies. Metformin has been associated with reduced risk of certain cancers, including PC, in some observational clinical studies. We assessed whether metformin use was associated with PC risk among those with type 2 diabetes (DM2), and whether metformin use modulated the association between DM2 and risk of PC. In total, 536 PC cases and 869 frequency-matched controls were recruited predominantly from University of California San Francisco medical clinics from 2006 to 2011. Eligible participants completed direct interviews using a structured risk factor questionnaire. The association between metformin use and PC risk was assessed using propensity score-weighted unconditional logistic regression methods in analyses restricted to diabetics and adjusted multivariable logistic models in the total study population. Ever use of metformin was not associated with PC risk in analyses restricted to DM2 (N = 170) participants (adjusted OR: 1.01, 95% CI: 0.61-1.68). In the total study population (N = 1,405) using nondiabetics as the referent group, PC risk was inversely associated with diabetes duration (ptrend < 0.001). Further, when DM2 participants were grouped by ever/never use of metformin and compared with nondiabetics, metformin use did not affect the association between DM2 and PC risk (never users: OR: 1.44, 95% CI: 0.78-2.67; ever users: OR: 1.19, 95% CI: 0.72-1.99). Results from our clinic-based case-control study suggest that metformin use is not associated with PC risk among those with DM2 and does not alter the association between DM2 and PC risk.

A patient with cholangiocarcinoma demonstrating pathologic complete response to chemotherapy: exploring the role of neoadjuvant therapy in biliary tract cancer.

The role of neoadjuvant chemotherapy and/or radiation for localized or potentially resectable cholangiocarcinoma (CCA) has not been well established. We present here the case of a patient with an extrahepatic CCA who achieved a pathologic complete response after undergoing preoperative gemcitabine-based chemotherapy, without sequential or concurrent use of radiation. Further evaluation of neoadjuvant strategies in CCA, including not only combined-modality therapy but also the use of chemotherapy exclusively, is warranted in prospective study design.

Hepatitis B viral reactivation secondary to imatinib treatment in a patient with gastrointestinal stromal tumor.

Hepatitis B virus (HBV) reactivation is a known risk in cancer patients receiving cytotoxic or immunosuppressive therapy; however, the risk associated with newer molecularly-targeted agents has not been well-quantified. Imatinib, a small molecule inhibitor directed against BCR-ABL, CKIT, and other tyrosine kinases, has been associated with HBV reactivation primarily in patients treated for chronic myelogenous leukemia. Herein we present the first reported case of a patient who developed HBV reactivation while receiving imatinib therapy for a gastrointestinal stromal tumor (GIST) in the adjuvant setting. This eventually resulted in fulminant liver failure and was effectively treated with living-related donor liver transplant and anti-viral medication. Currently, no guidelines exist for HBV screening prior to imatinib therapy. This report emphasizes the need for such guidelines and supports the idea that viral reactivation is a risk in all imatinib-treated patients, regardless of the underlying disease.

Beyond first-line chemotherapy for advanced pancreatic cancer: an expanding array of therapeutic options?

While an increasing number of therapeutic options are now available for the first-line treatment of locally advanced or metastatic pancreatic cancer, the optimal choice for treatment in the second-line setting and beyond is less well defined. A variety of cytotoxic agents, either alone or in combination, have been evaluated, although primarily in the context of small single-arm or retrospective studies. Most regimens have been associated with median progression-free survival rates in the range of 2-4 mo and overall survival rates between 4-8 mo, highlighting the very poor prognosis of patients who are candidates for such treatment. Targeted therapies studied in this chemotherapy-refractory setting, meanwhile, have produced even worse efficacy results. In the current article, we review the clinical evidence for treatment of refractory disease, primarily in patients who have progressed on front-line gemcitabine-based chemotherapy. In the process, we highlight the limitations of the available data to date as well as some of the challenges in designing appropriate clinical trials in this salvage setting, including how to select an appropriate control arm given the absence of a well-established reference standard, and the importance of incorporating predictive biomarkers and quality of life measures whenever possible into study design.

Loss of the SxxSS motif in a human T-cell factor-4 isoform confers hypoxia resistance to liver cancer: an oncogenic switch in Wnt signaling.

PURPOSE: Aberrantly activated Wnt/ß-catenin signaling is important in hepatocellular carcinoma (HCC) development. Downstream gene expressions involving the Wnt/ß-catenin cascade occur through T-cell factor (TCF) proteins. Here, we show the oncogenic potential of human TCF-4 isoforms based on the expression of a single conserved SxxSS motif. METHODS: We investigated the TCF-4J and K isoform pair characterized by the presence (K) or absence (J) of the SxxSS motif. The mRNA expression profiles were examined in 47 pairs of human HCCs and adjacent non-cancerous liver tissues by RT-PCR. Proliferation, sphere assays and immunoblot analysis were performed under normoxia and hypoxia conditions. The ability of HCC cells overexpressing TCF-4J (J cells) and K (K cells) to grow as solid tumors in nude mice was explored. RESULTS: TCF-4J expression was significantly upregulated in HCC tumors compared to corresponding peritumor and normal liver and was preferentially expressed in poorly differentiated HCCs. In contrast, TCF-4K was downregulated in those same HCC tumors. TCF-4J-overexpressing HCC cells (J cells) revealed a survival advantage under hypoxic conditions, high proliferation rate and formation of aggregates/spheres compared to overexpression of TCF-4K (K cells). The hypoxic J cells had high expression levels of HIF-2α and EGFR as possible mechanisms to promote tumorigenesis. Increased stability of HIF-2α under hypoxia in J cells was associated with a decreased level of von Hippel-Lindau (VHL) protein, a known E3 ligase for HIF-αs. In a xenograft model, the J cells rapidly developed tumors compared to K cells. Tumor tissues derived from J cells exhibited high expression levels of HIF-2α and EGFR compared to the slow developing and small K cell derived tumors. CONCLUSIONS: Our results suggest that the specific TCF-4J isoform, which lacks a regulatory SxxSS motif, has robust tumor-initiating potential under hypoxic conditions.

Role of Raf Kinase Inhibitor Protein in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) accounts for 80-90% of primary liver tumors and is one of the most common and devastating malignant diseases worldwide. The MAPK signaling pathway is activated in over 90% of HCCs, and RKIP has been identified as an inhibitor of the MAPK pathway. It has been observed that downregulation of RKIP expression in HCC tumors contributes to constitutive activation of the ERK/MAPK pathway and promotes proliferation and migration of HCC cells. More important, activation of IGF-I/ERK/MAPK pathways can be blocked by restoration of RKIP levels. The protein levels of RKIP are significantly reduced in HCC, whereas mRNA levels only decreased in 41% of HCC samples studied, suggesting that the downregulation of RKIP in HCC may be influenced through multiple mechanisms both at the mRNA and protein levels. In this context, mTOR inhibitor, insulin, and proteasome inhibitors were found to modulate RKIP expression in FOCUS HCC cells. A better understating of mechanisms by which RKIP expression is downregulated in HCC may be critical to develop a possible target for therapeutic intervention of HCC.

Low density contrast agents for x-ray phase contrast imaging: the use of ambient air for x-ray angiography of excised murine liver tissue.

We report a new preparative method for providing contrast through reduction in electron density that is uniquely suited for propagation-based differential x-ray phase contrast imaging. The method, which results in an air or fluid filled vasculature, makes possible visualization of the smallest microvessels, roughly down to 15 microm, in an excised murine liver, while preserving the tissue for subsequent histological workup. We show the utility of spatial frequency filtering for increasing the visibility of minute features characteristic of phase contrast imaging, and the capability of tomographic reconstruction to reveal microvessel structure and three-dimensional visualization of the sample. The effect of water evaporation from livers during x-ray imaging on the visibility of blood vessels is delineated. The deformed vascular tree in a cancerous murine liver is imaged.