Unresectable Pancreatic Ductal Adenocarcinoma Research Articles

LOAd703, an oncolytic virus-based immunostimulatory gene therapy, combined with chemotherapy for unresectable or metastatic pancreatic cancer (LOKON001): results from arm 1 of a non-randomised, single-centre, phase 1/2 study

Pancreatic ductal adenocarcinoma is characterised by low immunogenicity and an immunosuppressive tumour microenvironment. LOAd703, an oncolytic adenovirus with transgenes encoding TMZ-CD40L and 4-1BBL, lyses cancer cells selectively, activates cytotoxic T cells, and induces tumour regression in preclinical models. The aim of this study was to evaluate the safety and feasibility of combining LOAd703 with chemotherapy for advanced pancreatic ductal adenocarcinoma. LOKON001 was a non-randomised, phase 1/2 study conducted at the Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA, and consisted of two arms conducted sequentially; the results of arm 1 are presented here. In arm 1, patients 18 years or older with previously treated or treatment-naive unresectable or metastatic pancreatic ductal adenocarcinoma were treated with standard 28-day cycles of intravenous nab-paclitaxel 125 mg/m2 plus gemcitabine 1000 mg/m2 (up to 12 cycles) and intratumoural injections of LOAd703 every 2 weeks. Patients were assigned using Bayesian optimal interval design to receive 500 μL of LOAd703 at 5 × 1010 (dose 1), 1 × 1011 (dose 2), or 5 × 1011 (dose 3) viral particles per injection, injected endoscopically or percutaneously into the pancreatic tumour or a metastasis for six injections. The primary endpoints were safety and treatment-emergent immune response in patients who received at least one dose of LOAd703, and antitumour activity was a secondary endpoint. This study was registered with ClinicalTrials.gov, NCT02705196, arm 2 is ongoing and open to new participants. Between Dec 2, 2016, and Oct 17, 2019, 23 patients were assessed for eligibility, leading to 22 patients being enrolled. One patient withdrew consent, resulting in 21 patients (13 [62%] men and eight [38%] women) assigned to a dose group (three to dose 1, four to dose 2, and 14 to dose 3). 21 patients were evaluable for safety. Median follow-up time was 6 months (IQR 4-10), and data cutoff was Jan 5, 2023. The most common treatment-emergent adverse events overall were anaemia (96 [8%] of 1237 events), lymphopenia (86 [7%] events), hyperglycaemia (70 [6%] events), leukopenia (63 [5%] events), hypertension (62 [5%] events), and hypoalbuminaemia (61 [5%] events). The most common adverse events attributed to LOAd703 were fever (14 [67%] of 21 patients), fatigue (eight [38%]), chills (seven [33%]), and elevated liver enzymes (alanine aminotransferase in five [24%], alkaline phosphatase in four [19%], and aspartate aminotransferase in four [19%]), all of which were grade 1-2, except for a transient grade 3 aminotransferase elevation occurring at dose 3. A maximum tolerated dose was not reached, thereby establishing dose 3 as the highest-evaluated safe dose when combined with nab-paclitaxel plus gemcitabine. Proportions of CD8+ effector memory cells and adenovirus-specific T cells increased after LOAd703 injections in 15 (94%) of 16 patients for whom T-cell assays could be performed. Eight (44%, 95% CI 25-66) of 18 patients evaluable for activity had an objective response. Combining LOAd703 with nab-paclitaxel plus gemcitabine in patients with advanced pancreatic ductal adenocarcinoma was feasible and safe. To build upon this novel chemoimmunotherapeutic approach, arm 2 of LOKON001, which combines LOAd703, nab-paclitaxel plus gemcitabine, and atezolizumab, is ongoing. Lokon Pharma, the Swedish Cancer Society, and the Swedish Research Council.

Assessing Endoscopic Ultrasound-Guided Radiofrequency Ablation in Unresectable Pancreatic Ductal Adenocarcinoma: A Single-Center Historic Cohort Study.

/aims: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has emerged as an alternative for the local treatment of unresectable pancreatic ductal adenocarcinoma (PDAC). We aim to assess the feasibility and safety of EUS-RFA in patients with unresectable PDAC. The following was a historic cohort compounded by locally advanced (LA) and metastatic (m) PDAC naïve patients, who underwent EUS-RFA between October 2019 to March 2022. EUS-RFA was performed with a 19-g needle electrode with a 10 mm active tip for energy delivery. Study primary endpoints were feasibility, safety, and clinical follow-up; secondary endpoints were performance status (PS), local control (LC) and overall survival (OS). Twenty-six patients were selected: 15/26 LA-PDAC and 11/26 mPDAC. Technical success was achieved in all patients with no major adverse events. Six months after EUS-RFA, OS was 11/26 (42.3%), with significant PS improvement (P=.03). LC was achieved, with tumor reduction from 39.5 to 26 mm (P=.04). Post-treatment hypodense necrotic area was observed at six-month follow-up in 11/11 alive cases. Metastatic disease was a significant factor for OS worsening (HR 5.021; IC 95% 1.589 - 15.87; P=.004) CONCLUSIONS: EUS-RFA of pancreatic adenocarcinoma is a minimally invasive and safe technique that may have an important role as targeted therapy for local treatment of unresectable cases, as well as an alternative for poor surgical candidates. Also, RFA may play a role in downstaging cancer with potential OS increase in non-metastatic cases. Large prospective cohorts are required to evaluate this technique in clinical practice.

Pretherapeutic factors predicting conversion surgery in unresectable pancreatic ductal adenocarcinoma: A retrospective study.

Recently, conversion surgery (CS) has been reported to improve the prognosis in patients with unresectable pancreatic ductal adenocarcinoma (UR-PDAC) with a favorable response to intense chemotherapy or chemoradiotherapy. However, few pretherapeutic parameters predict the attainability of CS in patients with UR-PDAC. The present study aimed to explore the pretherapeutic predictors for the attainability of CS in patients with UR-PDAC. The present study retrospectively evaluated 130 patients with UR-PDAC treated at Gifu University Hospital (Gifu, Japan) from January 2015 to December 2021. Survival analysis was performed using the Simon and Makuch-modified Kaplan-Meier method. The hazard ratio (HR) was estimated using a time-varying Cox regression model. The association between each predictor and CS was evaluated using the univariate analysis and age-adjusted Fine-Gray sub-distribution hazard model. The bootstrap bias-corrected area under the receiver operating characteristic curve analysis for predicting CS was used to assess the cut-off values for each predictor. The cumulative incidence rate was calculated with CS as the outcome when divided into two groups based on the cut-off value of each pretherapeutic predictor. Among the 130 patients included in the analysis, only 14 (11%) underwent CS. The median survival time was significantly longer in patients who underwent CS compared with patients without CS (56.3 vs. 14.1 months; P<0.001). The age-adjusted Fine-Gray sub-distribution hazard regression showed that the total protein (TP) [HR 2.81, 95% confidence interval (CI) 1.19-6.65; P=0.018], neutrophil-to-lymphocyte ratio (NLR) (HR 0.53, 95% CI 0.31-0.90; P=0.020), and lymphocyte-to-monocyte ratio (LMR) (HR 1.28, 95% CI 1.07-1.53; P=0.006) were significantly associated with CS. Moreover, TP ≥6.8, NLR <2.84 and LMR ≥3.87 were associated with a higher cumulative incidence of CS. In conclusion, pretherapeutic TP, NLR and LMR are clinically feasible biomarkers for predicting the attainability of CS in patients with UR-PDAC.

New cutoff of CA19-9 values for predicting pancreatic cancer using liquid biopsy.

692 Background: Carbohydrate antigen 19-9 (CA19-9) is the biomarker most commonly used as a diagnostic aid for treatment efficacy and survival prediction for pancreatic ductal adenocarcinoma (PDAC). However, the cutoff value of CA19-9 is still being discussed. Instead, circulating tumor DNA (ctDNA) has been reported as a new biomarker for PDAC. Our previous study showed a correlation between CA19-9 levels and KRAS mutated ctDNA in the blood of PDAC patients. Based on this correlation, we validated an appropriate cutoff value for CA19-9 before surgery. Methods: We monitored continuously CA19-9 values and KRAS-mutated ctDNAs in unresectable PDAC patients (N=22) who underwent chemotherapy in 2015 to 2017. KRAS mutation in tumor tissues and mutated circulating tumor DNA (MctDNA) in plasma was analyzed for mutations by digital polymerase chain reaction (ddPCR) in 22 patients with pancreatic cancer. KRAS point mutation in plasma was analyzed, according to KRAS point mutation in tissue (ex. 12D, 12V). Receiver operating characteristics (ROC) curve analysis was plotted to determine new cutoff of CA19-9 value that emerged KRAS-mutated ctDNA in the longitudinal monitoring. Recurrence-free survival (RFS) and overall survival (OS) of 60 patients who underwent surgery for resectable PDAC in 2005 to 2013 were analyzed according to many survival variables including new cutoff of CA19-9 value and median CA19-9 before operation. Results: Receiver operating characteristic curve analysis identified 949.7 U/mL of CA19-9 as the cutoff value corresponding to the presence of KRAS mutated ctDNA. The median value of CA19-9 was 221.1 U/mL. Subsequently, these values were verified for their prognostic values of RFS and OS in 60 patients who underwent surgery in 2005 to 2013. Multivariate analysis revealed that 949.7 U/mL of CA19-9 was an independent risk factor for RFS and OS in these patients (P = 0.010 and = P = 0.001, respectively), along with lymph node metastasis( P = 0.017 and P = 0.008), unlike the median CA19-9 level (P = 0.210 and P = 0.150). Conclusions: The results of this study demonstrate that preoperative 949.7 U/mL ≥ CA19-9 may be associate with poor prognosis in PDAC. In summary, our study demonstrated, for the first time, that the adjusted cutoff value of CA19-9 was an important biomarker for the prediction of recurrence and prognosis in patients with resected PDAC. Patients with high levels of CA19-9 before surgery had a higher risk of recurrence and poorer prognosis than those with low levels of CA19-9, therefore they may have benefitted more from drug treatment than surgical intervention. Nevertheless, appropriate clinical decision-making for patients with high CA19-9 levels should be confirmed in future clinical trials. Although our study results should be interpreted within the study limitations and further examinations are required to draw a definitive conclusion, we believe that it clarifies the selection of patients with PDAC.

Stereotactic radiotherapy plus anti PD-1 therapy in patients with locally advanced unresectable pancreatic cancer: Results from a phase 1/2 clinical trial (CA209-9KH).

649 Background: The outcomes after the treatment for pancreatic ductal adenocarcinoma (PDAC) are generally disappointing. Except for MSI high tumors, PDAC is considered to be resistant to immune checkpoint inhibitors (ICI). Radiotherapy is thought to be a potential option to foster the effect of ICI. This investigator-initiated trial evaluated safety and efficacy of combining stereotactic radiotherapy (SRT) and ICI. Methods: In this open-label, multicenter phase 1/2 study, patients (pts) aged ≥ 18 years with histologically confirmed locally advanced unresectable PDAC with no distant metastases were enrolled after initial four cycles of induction chemotherapy with FOLFIRINOX. The experimental treatment consisted of SRT (32 Gy in 4 fractions/4 weeks) and sequential nivolumab (N) therapy (3mg/kg every two weeks) administered until disease progression or unacceptable toxicity. After N discontinuation pts could continue treatment with standard chemotherapy regimens. The primary end point was safety (events graded according to NCI CTCAE 4.03 criteria). The secondary objectives were progression free survival (PFS), overall survival (OS), evaluation of selected biomarkers, and quality of life (QoL; EORTC QLQ-C30 questionnaire). The PFS and OS were defined as the time from enrollment to event (i.e., did not include 3-month of ICT and screening). Results: A total of 22 pts. were screened, and 15 pts. were enrolled. Median age was 58 (range 38-74) years, and 53 % were males. All tumors were microsatellite (MS) stable or had unknown MS status. All patients underwent SRT according to the study protocol and all started N. The median number of N cycles was 11 (range 2-17). The toxicity of SRT was low and non-significant. The toxicity of N therapy was expectable. No Grade 4-5 toxicity was observed. Three pts. discontinued therapy because of toxicity (liver test elevation in two cases and unmanageable arthralgia). Median PFS and OS were 8.1 and 13.0 months, resp.; 12-month PFS and OS were 0 % and 66.7%, resp.; and 24-month OS was 8.9 %. The level of selected biomarkers correlated with clinical or radiological disease control. The QoL assessed by pts during the therapy was acceptable, deterioration of QoL in most cases occurred with tumor progression. Conclusions: The toxicity of SRT and N therapy was low and acceptable. There was no unexpected toxicity of combination of SRT of PDAC primary tumor and N, but this regimen did not lead to any long-term treatment responses. Trial registration: EudraCT: 2017-003404-52; ClinicalTrials.gov: NCT04098432. The study was financially supported by Bristol-Meyer-Squibb. Clinical trial information: NCT04098432 .

Survival outcome of different treatment sequences in patients with locally advanced and metastatic pancreatic cancer

BackgroundDespite some therapeutic advances, improvement in survival rates of unresectable and/or metastatic pancreatic ductal adenocarcinoma (PDAC) has been minimal over recent decade. We aimed to evaluate the impact of different treatment sequences on clinical outcomes of advanced PDAC at our academic institution.MethodsIn this single institution retrospective analysis, we assessed characteristics and survival rates of unresectable and/or metastatic pancreatic PDAC patients who started a systemic treatment between 01/2015 and 12/2021. Survival analyses were performed by Kaplan-Meier and Cox proportional hazards model.ResultsThe number of 285 patients received at least two lines of treatment, but only 137 patients were suitable for third-line treatment. Subgroup analysis showed that thirty-seven patients received A line (gemcitabine/nab-paclitaxel or nab-paclitaxel combined therapy to FOLFIRINOX) therapy, 37 patients received B line (nab-paclitaxel combined therapy to gemcitabine combined therapy to FOLFIRINOX) therapy, 21 patients received C line (nab-paclitaxel combined therapy to gemcitabine combined therapy to oxaliplatin or irinotecan combined therapy) therapy. Survival rates for different treatment lines were significantly different and median overall survival (OS) was 14.00, 18.00, and 14.00 months, respectively (p<0.05).ConclusionOur study provides real-world evidence for the effectiveness of different treatment sequences and underscores the treatment sequences on survival outcome when considering the entire management in advanced PDAC.

Conversion surgery for initially unresectable locally advanced pancreatic ductal adenocarcinoma after chemotherapy followed by carbon-ion radiotherapy: a case report

BackgroundRecent advances in chemotherapy and chemoradiotherapy have enabled conversion surgery (CS) to be performed for selected patients with initially unresectable locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC). Many studies indicate CS might extend the survival of patients with initially unresectable LA PDAC. However, several clinical questions concerning CS remain, such as the optimal preoperative treatment. Carbon-ion radiotherapy (CIRT) is a unique radiotherapy that offers higher biological effectiveness than conventional radiotherapy. Here, we report a long-term survival case with initially unresectable LA PDAC who underwent CS after chemotherapy followed by CIRT.Case presentationThe patient was a 72-year-old Japanese woman with unresectable LA pancreatic head cancer with tumor contact to the superior mesenteric artery (SMA). She underwent four courses of chemotherapy (gemcitabine plus nanoparticle albumin-bound paclitaxel). However, the lesion did not shrink and tumor contact with the SMA did not improve after chemotherapy. Because the probability of achieving curative resection was judged to be low, she underwent radical dose CIRT, and chemotherapy was continued. She complained of vomiting 2 months after CIRT. Although imaging studies showed no tumor growth or metastasis, a duodenal obstruction which was speculated to be an adverse effect of CIRT was observed. She could not eat solid food and a trans-nasal feeding tube was inserted. Therapeutic intervention was required to enable enteral nutrition. We proposed several treatment options. She chose resection with the expectation of an anti-tumor effect of chemotherapy and CIRT rather than course observation with tube feeding or bypass surgery. Therefore, subtotal-stomach-preserving pancreatoduodenectomy with portal vein resection was performed as CS. Pathological examination of the resected specimen revealed an R0 resection with a histological response of Evans grade IIA. Postoperatively, she recovered uneventfully. Adjuvant chemotherapy with tegafur/gimeracil/oteracil (S1) was administrated. At the time of this report, 5 years have passed since the initial consultation and she has experienced no tumor recurrence.ConclusionsThe present case suggests that multidisciplinary treatment consisting of a combination of recent chemotherapy and CIRT may be beneficial for unresectable LA PDAC. However, further studies are required to assess the true efficacy of this treatment strategy.

Phase II study of SOXIRI (S-1/oxaliplatin/irinotecan) chemotherapy in patients with unresectable pancreatic ductal adenocarcinoma

BackgroundTo provide data on the safety and efficacy of a combination chemotherapy regimen consisting of S-1, oxaliplatin, and irinotecan (SOXIRI) as a first-line therapy in unresectable pancreatic ductal adenocarcinoma (UPDA) patients. MethodsPatients with UPDA and no prior treatment chemotherapy in the UPDA setting were enrolled. The primary endpoint was the objective response rate (ORR). Secondary endpoints were overall survival (OS), progression-free survival (PFS) and adverse events. Patients received 80 mg/m2 S-1 twice a day for 2 weeks in an alternate-day administration cycle, 85 mg/m2 oxaliplatin on Day 1, and 150 mg/m2 irinotecan on Day 1 of a 2-week cycle. ResultsIn these 62 enrolled patients, the ORR was 27.4 %, median OS was 12.1 months, and median PFS was 6.5 months. Major grade 3 or 4 toxicity included neutropenia (22.3 %), leucopenia (16.1 %), nausea (9.7 %), vomiting (9.7 %), thrombocytopenia (6.5 %), anorexia (8.5 %), anemia (4.8 %), and diarrhea (1.6 %). No treatment-related deaths occurred. In addition, the analysis of 32 patients suffering pain revealed that the rate of pain relief was 34.4 %. ConclusionSOXIRI might be a standard regimen with an acceptable toxicity profile and favorable efficacy for use as chemotherapy in patients with UPDA.

REV7 is involved in outcomes of platinum-based chemotherapy in pancreatic cancer by controlling the DNA damage response.

REV7 is a multifunctional protein implicated in various biological processes, including DNA damage response. REV7 expression in human cancer cells affects their sensitivity to DNA-damaging agents. In the present study, we investigated the significance of REV7 in pancreatic ductal adenocarcinoma (PDAC). REV7 expression was immunohistochemically examined in 92 resected PDAC specimens and 60 endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) specimens of unresectable PDAC treated with platinum-based chemotherapy, and its association with clinicopathologic features was analyzed. Although REV7 expression was not significantly associated with the progression of primary tumors (T-factor and Stage) in either resected or unresectable PDAC, decreased levels of REV7 expression in EUS-FNAB specimens of unresectable PDAC were significantly associated with better outcomes of platinum-based chemotherapy and a favorable prognosis. REV7-deficient PDAC cell lines showed suppressed cell growth and enhanced sensitivity to cisplatin invitro. Tumor-bearing mice generated using REV7-deficient PDAC cell lines also showed enhanced sensitivity to cisplatin invivo. RNA sequencing analysis using WT and REV7-deficient PDAC cell lines revealed that REV7 inactivation promoted the downregulation of genes involved in the DNA repair and the upregulation of genes involved in apoptosis. Our results indicate that decreased expression of REV7 is associated with better outcomes of platinum-based chemotherapy in PDAC by suppressing the DNA damage response. It is also suggested that REV7 is a useful biomarker for predicting the outcome of platinum-based chemotherapy and the prognosis of unresectable PDAC and is a potential target for PDAC treatment.

High overall copy number variation burden by genome-wide methylation profiling holds negative prognostic value in surgically treated pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of cancer with an overall 5-year survival of around 10 %. New prognostic tools to stratify patients are needed. Our main aim was to evaluate the prognostic value of overall copy number variation (CNV) burden in surgically treated PDAC. DNA extracted from 108 surgical PDAC specimens was examined to collect data on the genome-wide DNA methylation status of >850,000 CpG sites in promoter, gene body, and enhancer regions (Illumina Infinium Methylation EPIC BeadChip Kit). CNV profiles were obtained and all PDACs were stratified into one of three groups: Low, moderate, or high overall CNV burden. Tumors histologically showing a dominant conventional and/or tubulopapillary pattern in 60 %–100 % and 0–59 % were categorized as Group A and Group B as per Kalimuthu. We also performed targeted next-generation sequencing (NGS) and immunohistochemistry. High overall CNV burden held independent negative prognostic value with poor survival (HR 4.01 (95%CI 1.96–8.19), p = 0.00014) and was more frequent in Group B (p = 0.0003). Most frequent chromosomal arm-level aberrations were gains of 8q (29 %) and 1q (19 %) and losses of 17p (55 %), 18q (43 %), 6q (37 %), 9p (36 %), 6p (26 %), 19p (26 %), and 8p (25 %). Most frequent mutations found were in KRAS (95 %), TP53 (62 %), CDKN2A (24 %), SMAD4 (23 %), ATM (9 %), ARID1A (7 %), RNF43 (7 %), GNAS (6 %), and KDM6A (6 %). Group A PDACs showed more frequently KRAS variants other than Gly12Val and Gly12Asp (p = 0.012). Our data indicate that overall CNV burden using genome-wide methylation profiling may be a useful prognostic tool in surgically treated PDAC. Importantly, our approach, using data from genome-wide methylation profiling for analysis of overall CNV burden, can be performed on formalin-fixed and paraffin embedded PDAC tissues. Future studies should examine the prognostic value of overall CNV burden in unresectable PDAC.

Implication of Skeletal Muscle Loss in the Prognosis of Patients with Pancreatic Ductal Adenocarcinoma Receiving Chemotherapy.

Objective The effect of sarcopenia on the prognosis of patients undergoing chemotherapy for unresectable pancreatic ductal adenocarcinoma remains largely unexplored. In this retrospective study, we investigated the relationship between sarcopenia and the prognosis of patients receiving first-line nanoparticle albumin-bound paclitaxel plus gemcitabine for unresectable pancreatic ductal adenocarcinoma. Patients and Methods We enrolled 251 patients with unresectable metastatic or locally advanced pancreatic ductal adenocarcinoma who had received chemotherapy between January 2015 and December 2020 at Kitasato University Hospital. Univariate and multivariate analyses were performed using the stratified Cox proportional hazards model to determine variables significantly associated with the progression-free and overall survival. Propensity score matching was performed to mitigate selection bias effects. Results In the propensity score-matched cohort, the progression-free and overall survival were not significantly different between the sarcopenia and non-sarcopenia groups (p=0.335, and 0.679 respectively). The skeletal muscle index decreased by 4.4% and 6.5% in the sarcopenia and non-sarcopenia groups, respectively, during the early treatment phase (p=0.084). There were no significant differences between groups with regard to major adverse events or drug toxicity occurrences. Both the progression-free and overall survival were significantly shorter in the skeletal muscle index loss group than in the non-skeletal muscle index loss group (p=0.026 and 0.045, respectively). Conclusions Skeletal muscle index loss during the initial treatment phase may be an early marker for the long-term prognosis of patients receiving nanoparticle albumin-bound paclitaxel plus gemcitabine as first-line treatment for unresectable pancreatic ductal adenocarcinoma.

CT-Guided Online Adaptive Stereotactic Body Radiotherapy for Pancreas Ductal Adenocarcinoma: Dosimetric and Initial Clinical Experience

Retrospective analysis suggests that dose escalation to a biologically effective dose of more than 70 Gy may improve overall survival in patients with pancreatic ductal adenocarcinoma (PDAC), but such treatments in practice are limited by proximity of organs at risk (OARs). We hypothesized that CT-guided online adaptive radiotherapy (OART) can account for interfraction movement of OARs, reduce dose to OARs, and improve coverage of targets. This is a single institution retrospective analysis of patients with PDAC treated with OART on a CBCT-based OART platform. All patients were treated to 40 Gy in 5 fractions. PTV overlapping with a 5 mm planning risk volume expansion on the stomach, duodenum and bowel received 25 Gy. Initial treatment plans were created conventionally. For each fraction, PTV and OAR volumes were recontoured with AI assistance after initial cone beam CT (CBCT). The adapted plan was calculated, underwent QA, and then compared to the scheduled plan. A second CBCT was obtained prior to delivery of the selected plan. Total treatment time (first CBCT to end of radiation delivery) and active physician time (first to second CBCT) were recorded. PTV_4000 V95%, PTV_2500 V95%, and D0.03 cc to stomach, duodenum and bowel were reported for scheduled (S) and adapted (A) plans. CTCAEv5.0 toxicities were recorded. Statistical analysis was performed using a two-sided T test and α of 0.05. Seven patients with unresectable or locally-recurrent PDAC were analyzed, with a total of 35 fractions. Average total time was 33:00 minutes (22:25-49:40) and average active time was 22:48 minutes (14:15-39:34). All fractions were treated with adapted plans. All adapted plans met PTV_4000 V95.0% > 95.0% coverage goal and OAR dose constraints. Dosimetric data for scheduled and adapted plans per fraction are in Table 1. Median follow up was 1.7 months. 5 (71%) patients experienced either Grade 1 or 2 toxicities. No patients experienced Grade 3+ toxicities. Daily OART significantly reduced dose OARs while achieving superior PTV coverage. Treatment was generally well tolerated with no grade 3+ acute toxicity, and required only 22:48 minutes on average of active physician time. Our initial clinical experience demonstrates OART allows for safe dose escalation in the treatment of PDAC.

Persister cell phenotypes contribute to poor patient outcomes after neoadjuvant chemotherapy in PDAC

Neoadjuvant chemotherapy can improve the survival of individuals with borderline and unresectable pancreatic ductal adenocarcinoma; however, heterogeneous responses to chemotherapy remain a significant clinical challenge. Here, we performed RNA sequencing (n = 97) and multiplexed immunofluorescence (n = 122) on chemo-naive and postchemotherapy (post-CTX) resected patient samples (chemoradiotherapy excluded) to define the impact of neoadjuvant chemotherapy. Transcriptome analysis combined with high-resolution mapping of whole-tissue sections identified GATA6 (classical), KRT17 (basal-like) and cytochrome P450 3A (CYP3A) coexpressing cells that were preferentially enriched in post-CTX resected samples. The persistence of GATA6hi and KRT17hi cells post-CTX was significantly associated with poor survival after mFOLFIRINOX (mFFX), but not gemcitabine (GEM), treatment. Analysis of organoid models derived from chemo-naive and post-CTX samples demonstrated that CYP3A expression is a predictor of chemotherapy response and that CYP3A-expressing drug detoxification pathways can metabolize the prodrug irinotecan, a constituent of mFFX. These findings identify CYP3A-expressing drug-tolerant cell phenotypes in residual disease that may ultimately inform adjuvant treatment selection.

EUS-guided radiofrequency ablation plus chemotherapy versus chemotherapy alone for pancreatic cancer (ERAP): An observational open-label pilot study.

No study has compared EUS-guided radiofrequency ablation (EUS-RFA) plus systemic chemotherapy (CMT) with CMT alone for unresectable pancreatic ductal adenocarcinoma. This study compared the results of treatment in patients receiving EUS-RFA plus concomitant CMT (group A; n = 14) with those receiving CMT (group B; n = 14) as a pilot study. From July 2017 to August 2018, 4 and 2 patients from groups A and B, respectively, withdrew from the study because of progression of the disease. In total, 10 and 12 patients from groups A and B, respectively, completed the study. All 30 EUS-RFA procedures were successful. Mean maximal tumor diameter before treatment of group A (n = 10) versus B (n = 12) was 62.2 ± 21.0 versus 50.5 ± 22.0 mm, respectively (P = not significant). After treatment, no statistically significant difference in mean maximal tumor diameter was found between both groups. However, in group B, mean maximal tumor diameter was significantly increased from 50.5 ± 22.0 to 56.3 ± 18.7 mm, respectively (P = 0.017). Tumor necrosis occurred in group A versus B at 10 of 10 (100%) versus 6 of 12 (50%) patients, respectively (P = 0.014). After treatment, group A patients could reduce the mean narcotic pain drug dosage at 26.5 mg of morphine equivalent per day (from 63.6 to 37.1 mg, P = 0.022), whereas group B patients could not reduce the dosage of pain-controlled medication. No statistically significant difference in 6-month mortality rate was found. In group A, 1 procedure-related nonsevere adverse event (n = 1 of 30 [3.3%]) occurred in 1 patient (n = 1 of 14 [7.1%]). In this study, the mean tumor diameter of group B was significantly increased after the treatment. Group A had a significantly higher rate of necrosis of tumor and required less narcotic.

Photodynamic Stromal Depletion in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest solid malignancies, with a five-year survival of less than 10%. The resistance of the disease and the associated lack of therapeutic response is attributed primarily to its dense, fibrotic stroma, which acts as a barrier to drug perfusion and permits tumour survival and invasion. As clinical trials of chemotherapy (CT), radiotherapy (RT), and targeted agents have not been successful, improving the survival rate in unresectable PDAC remains an urgent clinical need. Photodynamic stromal depletion (PSD) is a recent approach that uses visible or near-infrared light to destroy the desmoplastic tissue. Preclinical evidence suggests this can resensitise tumour cells to subsequent therapies whilst averting the tumorigenic effects of tumour-stromal cell interactions. So far, the pre-clinical studies have suggested that PDT can successfully mediate the destruction of various stromal elements without increasing the aggressiveness of the tumour. However, the complexity of this interplay, including the combined tumour promoting and suppressing effects, poses unknowns for the clinical application of photodynamic stromal depletion in PDAC.

Optimization of laser dosimetry based on patient-specific anatomical models for the ablation of pancreatic ductal adenocarcinoma tumor

Laser-induced thermotherapy has shown promising potential for the treatment of unresectable primary pancreatic ductal adenocarcinoma tumors. Nevertheless, heterogeneous tumor environment and complex thermal interaction phenomena that are established under hyperthermic conditions can lead to under/over estimation of laser thermotherapy efficacy. Using numerical modeling, this paper presents an optimized laser setting for Nd:YAG laser delivered by a bare optical fiber (300 µm in diameter) at 1064 nm working in continuous mode within a power range of 2–10 W. For the thermal analysis, patient-specific 3D models were used, consisting of tumors in different portions of the pancreas. The optimized laser power and time for ablating the tumor completely and producing thermal toxic effects on the possible residual tumor cells beyond the tumor margins were found to be 5 W for 550 s, 7 W for 550 s, and 8 W for 550 s for the pancreatic tail, body, and head tumors, respectively. Based on the results, during the laser irradiation at the optimized doses, thermal injury was not evident either in the 15 mm lateral distances from the optical fiber or in the nearby healthy organs. The present computational-based predictions are also in line with the previous ex vivo and in vivo studies, hence, they can assist in the estimation of the therapeutic outcome of laser ablation for pancreatic neoplasms prior to clinical trials.

Simultaneous Delivery of Dual Inhibitors of DNA Damage Repair Sensitizes Pancreatic Cancer Response to Irreversible Electroporation.

Pancreatic ductal adenocarcinoma (PDAC) is an abysmal disease refractory to most standard therapies. Irreversible electroporation (IRE) is a local ablative technique for the clinical treatment of solid tumors, including locally advanced and unresectable PDAC, by intratumorally delivering high-intensity electric pulses to permanently disrupt cell membranes and induce cell death. But the distribution of electric field is uneven within the tumor, and in some regions, tumor cells only experience temporary perturbation to their cell membrane, a phenomenon denoted as reversible electroporation (RE). These tumor cells may survive and therefore are the main culprit of tumor relapse after IRE. We herein showed that RE, although not killing tumor cells, induced DNA double-strand breaks and activated DNA damage repair (DDR) responses. Using reactive oxygen species-sensitive polymeric micelles coloaded with Olaparib, an inhibitor of poly(ADP-ribose) polymerase (PARP), and AZD0156, an inhibitor of ataxia telangiectasia mutated (ATM), the resultant nanoformulation (M-TK-OA) disrupted both homologous recombination and nonhomologous end joining signaling of the DDR response and impaired colony formation in pancreatic cancer cells after RE. The combination of IRE and M-TK-OA significantly prolonged animal survival in both subcutaneous and orthotopic murine PDAC models and elicited CD8+ T cell-mediated antitumor immunity with a sustained antitumor memory. The efficacy of combined IRE and M-TK-OA treatments was partially attributed to the activation of cyclic GMP-AMP synthase-stimulator of interferon genes innate immune responses. Our study suggests that dual inhibition of PARP and ATM with nanomedicine is a promising strategy to enhance the pancreatic cancer response to IRE.

Prognostic impact and risk factors of early recurrence after conversion surgery following neoadjuvant therapy in patients with initially unresectable pancreatic ductal adenocarcinoma

Prognostic impact and risk factors of early recurrence after conversion surgery following neoadjuvant therapy in patients with initially unresectable pancreatic ductal adenocarcinoma

Clinical outcomes of patients who are frail and elderly with unresectable pancreatic ductal adenocarcinoma (PDAC) treated with chemotherapy.

e16281 Background: Gemcitabine plus nab-paclitaxel and fluorouracil (5-FU)-based chemotherapy, such as FOLFIRINOX and FOLFOX, are standard treatment for unresectable PDAC. While older age and poor performance status (PS) are established negative prognostic factors, most clinical trials exclude these vulnerable populations. We aimed to assess the impact of older age and reduced PS in a real-world cohort of patients with PDAC who received chemotherapy. Methods: We retrospectively reviewed patients with unresectable or metastatic PDAC treated with first line (1L) therapy at Mount Sinai Health System from 1/2012 to 12/2021. We evaluated the association between age (≥ 75 vs. &lt; 75) and PS (ECOG PS ≥ 2 vs. &lt; 2) on overall survival (OS) and progression-free survival (PFS) using Kaplan-Meier estimates and multivariable Cox proportional hazards regression models. Chemotherapy tolerability was compared between these vulnerable and non-vulnerable populations using Chi-squared and Mann-Whitney tests. Results: 254 patients were evaluable. The median age of the full cohort was 66 years, and 130 (51.2%) patients were male. All patients had locally advanced (29.8%) or metastatic disease (70.2%). 47.6% of patients received gemcitabine-based and 49.6% received 5-FU-based 1L therapy. 41 patients (16.1%) had ECOG PS ≥ 2, and 60 (23.6%) were 75 or older. The type of 1L chemotherapy and rate of adverse events (AEs) requiring dose change or discontinuation did not differ significantly between patients with ECOG PS ≥ 2 and PS &lt; 2. However, patients with ECOG PS ≥ 2 received a shorter duration of therapy (median 2.6 vs. 3.4 months, P = 0.018), and the reason for discontinuation was more often due to clinical deterioration (56.1% vs. 29.6%, P = 0.004). As a result, fewer continued on to second-line (2L) therapy (29.3% vs. 51.2%, P = 0.016). ECOG PS ≥ 2 was associated with worse OS (HR 1.6, 95% CI 1.1-2.4, P = 0.016) in univariate analysis but not in multivariate analysis. ECOG PS ≥ 2 correlated with worse PFS in both univariate and multivariate analyses (HR 1.6, 95% CI 1.1-2.3, P = 0.009; HR 1.5, 95% CI 1.1-2.2, P = 0.023). Patients older than 75 were more likely to receive gemcitabine-based therapy (83.3% vs. 40.2%, P &lt; 0.001). While no significant differences in duration of therapy, rate of AEs, or reasons for discontinuation were observed based on age, older patients were less likely to receive 2L therapy (28.3% vs. 53.6%, P = 0.001). Age ≥ 75 was associated with worse OS (HR 1.6, 95% CI 1.19-2.25, P = 0.003) and worse PFS (HR 1.4, 95% CI 1.05-1.89, P = 0.024) in univariate but not multivariate analyses. Objective response rates did not differ based on PS or age. Conclusions: Reduced PS was associated with worse clinical outcomes and poor chemotherapy tolerance, but older patients appeared to tolerate gemcitabine-based regimens. Future studies should more specifically address the treatment needs of frail and elderly patients.

The Prognostic Utility of a Geriatric Assessment for Patients with Pancreatic Cancer Receiving Gemcitabine-based Chemotherapy: A Prospective Observational Study.

Objective To evaluate the effect of a pretreatment geriatric assessment on the clinical outcomes in older patients with unresectable or recurrent pancreatic ductal adenocarcinoma (PDAC) scheduled to receive gemcitabine (GEM)/GEM+nab-paclitaxel (GnP). Patients Older patients with unresectable PDAC scheduled to receive GEM/GnP who visited Kyorin University Hospital and cooperating institutions were enrolled and followed from April 2015 to March 2020. The maximum observation period was two years. All patients underwent a cancer-specific geriatric assessment (CSGA) and optional geriatric assessment (GA) before treatment initiation and two months after the start of treatment. The patients' background characteristics, tumor progression, tumor site, and regimen (GEM/GnP) were examined in a Cox proportional hazards model. The relationship between the overall survival (OS) and GA score was also determined. Eligible patients (age ≥70 years old with histopathologically confirmed unresectable or recurrent PDAC) were scheduled to receive first-line chemotherapy. Results The performance status (PS) and activities of daily living (ADL)/instrumental ADL (IADL) scores at baseline correlated with the OS. Furthermore, even in cases with normal baseline values, lower Frontal Assessment Battery scores and higher Geriatric Depression Scale-Short Form scores after treatment initiation were significantly correlated with OS. Conclusion The baseline PS, ADL, and IADL may be prognostic factors in older PDAC patients. In addition, a normal frontal lobe function and depression scores prior to treatment initiation that rapidly worsened during treatment were independently associated with a reduced OS. Selecting appropriate interventions and improving the therapeutic environment may prolong the OS in such patients.