Ductal Cancer Research Articles

Abstract B002: Modeling evolutionary therapy for GI malignancies

Abstract Despite development of personalized treatments GI cancer like pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC) remain dismal outcomes. While some patients are potentially curable with surgery and chemotherapy, most unresectable cases are invariably lethal. To advance patient care, we rely on clinical trials to test new therapeutic approaches. Here, we assume that the highest dose of a drug that does not cause severe toxicities is optimal for cancer treatment. However, this treatment strategy, in many cases, may be more harmful for the patient. Adopting principles from the field of evolutionary biology and pest management could offer more effective strategies that can be used for patients with metastatic PDAC and CRC. Resistance mechanisms are assumed to come with an energy cost, making the organism/cell less fit than others in the population. When high doses of treatment are applied, it results in a significant selection gradient by eliminating sensitive populations, freeing resources and facilitating resistant population growth. Such evolutionary dynamics and interactions within the tumor microenvironment can be modeled and exploited, in the form of adaptive strategies, for treatment of CRC and PDAC. It is our central hypothesis that integration of evolutionary dynamics and into PDAC and CRC treatment will delay emergence of resistance, enhance quality of life, and improve clinical outcomes. Our preliminary observations in co-cultured drug sensitive and resistant cell containing spheroids show that a higher proportion of drug sensitive cells inhibits the proliferation of drug resistant cells over time, in the presence of chemotherapeutic agents 5-FU and Oxaliplatin. We also demonstrate a role for the MLL family of histone methyltransferases in the epigenetic regulation of genes involved in chemoresistance. RNA-seq data has shown differential gene expression in metabolic genes regulated by histone methyltransferase KMT2A, KM2TB and KMT2D knockout (KO) cells including Gstt1, CYP26B1 and PYGL. In addition to this, KMT2A, KM2TB and KMT2D KOs show differential sensitivity to chemotherapeutic agents Gemcitabine, SN-38, 5-FU and Oxaliplatin. Further, analysis of KMT2A, KM2TB and KMT2D KO cells will provide mechanistic insight of the epigenetic regulation of metabolic patterns in drug resistant cells. This strategy would provide an approach for reducing exposure to toxic drugs, improving patient quality of life and renewing hope for prolonged control of metastatic PDAC and CRC. This proposal represents a bedside-to-bench-to-bedside project; identifying a shortcoming in how we currently treat PDAC and CRC patients, developing solutions in the lab and ultimately translating such strategies to benefit patients. Citation Format: Glancis Luzeena Raja Arul, Ezequiel Tolosa, Ryan M. Carr, Martin E. Fernandez-Zapico. Modeling evolutionary therapy for GI malignancies [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr B002.

Prognostic Significance of Low HER2 Expression in Patients With Early Hormone Receptor Positive Breast Cancer.

A possible role of antibody-drug conjugates against tumors with low HER2-expression, leads to the emergence of a new "low-HER2" classification in breast cancer, encompassing tumors from the hormonal-receptor-positive and the triple-negative subgroups. There is a need for data (clinical trial data and real-world evidence) that will accurately describe this population, the risk of recurrence and the possible benefit of HER2 targeted therapies. We retrospectively analyzed 949 patients from our Department databases, with hormonal receptor-positive and HER2-negative early breast cancer, for whom detailed data for immunohistochemical HER2-staining could be retrieved. HER2-low expression was detected in 66.6% of patients (472 IHC +1 and 160 IHC +2 and ISH-negative). Lobular, or mixed lobular and ductal cancers had a statistically significantly lower chance of being HER2-low when compared to pure infiltrative ductal carcinomas (53.1% vs. 69.3% respectively). HER2-low status was not prognostic for recurrence-free survival or response to neoadjuvant chemotherapy. There was a non-significant trend for increased risk of recurrence for HER2-low, compared to HER2-0, in patients with lobular or mixed lobular and ductal carcinomas (HR=2.192, 95% CI=0.819-5.912). Low expression of HER2 in hormonal receptor-positive early breast cancer does not affect prognosis but may lead to a shorter progression-free-survival in lobular and mixed ductal and lobular cancers. Despite optimal management, a large proportion of hormonal receptor-positive patients will relapse. Targeting HER2 in HER2-low cancers may offer a potential additional treatment strategy to improve survival of this group.

RNA N6-methyladenosine demethylase FTO promotes pancreatic cancer progression by inducing the autocrine activity of PDGFC in an m6A-YTHDF2-dependent manner

RNA N6-methyladenosine (m6A) is an emerging regulator of mRNA modifications and represents a novel player in tumorigenesis. Although it has functional significance in both pathological and physiological processes, the role of m6A modification in pancreatic ductal cancer (PDAC) remains elusive. Here, we showed that high fat mass and obesity-associated gene (FTO) expression was associated with a poor prognosis in PDAC patients and that suppression of FTO expression inhibited cell proliferation. Here, m6A sequencing (m6A-seq) was performed to screen genes targeted by FTO. The effects of FTO stimulation on the biological characteristics of pancreatic cancer cells, including proliferation and colony formation, were investigated in vitro and in vivo. The results indicate that FTO directly targets platelet-derived growth factor C (PDGFC) and stabilizes its mRNA expression in an m6A-YTHDF2-dependent manner. m6A-methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR), RNA immunoprecipitation (RIP), and luciferase reporter assays were employed to validate the specific binding of FTO to PDGFC. PDGFC upregulation led to reactivation of the Akt signaling pathway, promoting cell growth. Overall, our study reveals that FTO downregulation leads to increased m6A modifications in the 3ʹ UTR of PDGFC and then modulates the degradation of its transcriptional level in an m6A-YTHDF2-dependent manner, highlighting a potential therapeutic target for PDAC treatment and prognostic prediction.

In vitro breast cancer model with patient-specific morphological features for personalized medicine

In vitro cancer models that can simulate patient-specific drug responses for personalized medicine have attracted significant attention. However, the technologies used to produce such models can only recapitulate the morphological heterogeneity of human cancer tissue. Here, we developed a novel 3D technique to bioprint an in vitro breast cancer model with patient-specific morphological features. This model can precisely mimic the cellular microstructures of heterogeneous cancer tissues and produce drug responses similar to those of human cancers. We established a bioprinting process for generating cancer cell aggregates with ductal and solid tissue microstructures that reflected the morphology of breast cancer tissues, and applied it to develop breast cancer models. The genotypic and phenotypic characteristics of the ductal and solid cancer aggregates bioprinted with human breast cancer cells (MCF7, SKBR3, MDA-MB-231) were respectively similar to those of early and advanced cancers. The bioprinted solid cancer cell aggregates showed significantly higher hypoxia (>8 times) and mesenchymal (>2–4 times) marker expressions, invasion activity (>15 times), and drug resistance than the bioprinted ductal aggregates. Co-printing the ductal and solid aggregates produced heterogeneous breast cancer tissue models that recapitulated three different stages of breast cancer tissue morphology. The bioprinted cancer tissue models representing advanced cancer were more and less resistant, respectively, to the anthracycline antibiotic doxorubicin and the hypoxia-activated prodrug tirapazamine; these were analogous to the results in human cancer. The present findings showed that cancer cell aggregates can mimic the pathological micromorphology of human breast cancer tissue and they can be bioprinted to produce breast cancer tissue in vitro that can morphologically represent the clinical stage of cancer in individual patients.

Incidence, Treatment and Survival in Pancreatic Cancer- Data of the Nationwide Oncological Quality Conference from a Surgical Perspective

In recent years, there have been changes in the treatment of ductal pancreatic carcinoma with regard to multimodal therapy and also surgical therapy. These changes have not yet been explored in large nationwide studies in Germany. The present work gives an initial overview from a surgical perspective of the developments in diagnosis, therapy and survival of pancreatic cancer within the last 19 years in Germany. In this cohort of 18 clinical cancer registries in Germany, patients with a diagnosis of ductal pancreatic cancer from 2000-2018 were included. The patients were categorised according to the years of diagnosis (2000-2009 vs. 2010-2018) and treatment modalities and compared. In the cohort of approx. 48000 patients with ductal pancreatic cancer, the number of newly diagnosed cases increased from approx. 18000 to 30000 patients in the two ten-year periods. The median overall survival increased slightly but statistically significantly from 7.1 to 7.9 months (p<0.001). The resection rate increased from 25% to 32%, with the proportion of patients for whom no specific therapy was reported decreased by 11%. The rate of palliative chemotherapy and neoadjuvant chemotherapy also increased from 16% to 20% of the patients and from less than 1% to 2% of the patients, respectively. The median survival in the curatively treated subgroups was up to 24 months. The cancer registry data appear to confirm the known increase in the incidence of pancreatic cancer in the western world. Resection rates and the rates of treatment with neoadjuvant and palliative intent also increased. The overall survival of all patients with ductal pancreatic cancer only increased marginally. In the subgroups of patients who were treated with curative intent, however, significantly longer survival times were found.

Abstract PD14-08: Effectiveness of aromatase inhibitors versus tamoxifen in lobular compared to ductal carcinoma: Individual patient data meta-analysis of 9328 women with central histopathology, and 7654 women with e-Cadherin status

Abstract Background: In post-menopausal women with hormone receptor (HR) positive early breast cancer, aromatase inhibitors (AIs) are more effective than tamoxifen as endocrine therapy. However, some trial reports indicate greater benefit from AIs in lobular than ductal cancers. Invasive lobular cancer can be identified using conventional microscopy and/or immunohistochemistry for e-Cadherin status. We performed an individual patient data meta-analysis to explore possible differential treatment benefits for AI vs tamoxifen in women with lobular vs ductal hormone receptor positive breast cancer. Methods: Individual patient data were collected from three randomised controlled trials (BIG 01-98, TEAM and ATAC) of AI vs tamoxifen for postmenopausal women with estrogen receptor positive breast cancer, as well as results of central pathology review and e-Cadherin expression. Central pathology and e-Cadherin data were available on 9328 and 7654 women. Local pathology data was available for TEAM, BIG 01-98. Data were analysed using the same methodology as the previous EBCTCG meta-analysis of AI vs tamoxifen: results of different methods of diagnosing ductal vs lobular cancer were cross tabulated, and outcomes analysed using log-rank methods, yielding event rate ratios (RR) and confidence intervals. Interactions were evaluated using standard tests for heterogeneity; the primary outcomes were time to any invasive breast cancer recurrence, and time to distant recurrence. Results: Rates of lobular cancer were higher when assessed by central pathology (BIG 01-98 16%; ATAC 16%; TEAM 12%) than e-Cadherin (15% vs 14% vs 9%). Methods agreed in over 80% of cases classified as ductal using either pathology or e-Cadherin, while the agreement rate for lobular cancers was only about 50%. A similar pattern was seen comparing local pathology with either central pathology or e-Cadherin. Consequently, analyses were stratified by pathology and e-Cadherin both separately and together. Consistent with the previous meta-analysis there was a significant reduction in recurrence for AI compared to tamoxifen (RR 0.73 (0.61-0.87) p=0.0004). Exploration of interaction found no evidence of heterogeneity of treatment effect on recurrence by pathology (ductal HR 0.76 (0.64-0.89); lobular HR 0.76 (0.50-1.15) interaction p&amp;gt0.99; nor by e-Cadherin status (interaction p=0.9). No significant interactions were seen on other endpoints. Conclusion: Analyses of three large trials of adjuvant AI vs tamoxifen found discordance in identifying patients with lobular carcinoma by local or central pathology or e-Cadherin status, indicating variability in the consistency of diagnosis. The trials included showed a benefit for AI over tamoxifen in line with the previous meta-analysis, but with no evidence of differential efficacy in lobular compared to ductal carcinomas, however measured. These data cannot rule out smaller quantitative interactions or differences in site of recurrence: however, in contrast to earlier reports, this meta-analysis of the totality of the data does not identify ductal/lobular cancer as a predictive marker for differential endocrine treatment benefit. Citation Format: Robert K Hills, Steffi Oesterreich, Otto Metzger, David Dabbs, Hongchao Pan, Jeremy Braybrooke, Richard Gray, Richard Peto, Rosie Bradley, Ewan Straiton, Richard Berry, Daniel Rea, David Cameron, Jack Cuzick, Meredith Regan, Mitch Dowsett, Ivana Sestak, Jonas Bergh, Sandra M Swain, John Bartlett, Early Breast Cancer Trialists' Collaborative Group. Effectiveness of aromatase inhibitors versus tamoxifen in lobular compared to ductal carcinoma: Individual patient data meta-analysis of 9328 women with central histopathology, and 7654 women with e-Cadherin status [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD14-08.

Abstract P1-18-33: Real-world outcomes with palbociclib, abemaciclib and ribociclib; experience of a tertiary oncology centre in the United Kingdom

Abstract Background 3 CDK4/6 inhibitors (CDKi) were approved 2015-7 and are standard of care for metastatic hormone-positive breast cancer, in first line with letrozole or second with fulvestrant. The Phase III randomised controlled trials (RCTs) show similar hazard ratios (HR) for progression-free survival (PFS) of 0.46-0.58. We compared them head-to-head and examined subgroups for differential response. Methods We retrospectively reviewed all patients who received CDKi up to March 2020 at our Oncology centre and the 4 local hospitals we serve. Kaplan-Meier method was used to generate time-to-event curves and Log-rank test was used to compare differences. Results 208 patients had median age 61 and follow-up 20 months. Palbociclib was most frequently used (128 patients) followed by abemaciclib (60) and ribociclib (20). Overall, median PFS was 20.8 months (95% confidence interval, CI, 17.2-28.0) and median OS was not reached. On the Kaplan-Meier curve there is a visible benefit with ribociclib, but due to the small group size, this did not reach statistical significance (p = 0.143). Patients received CDKi with aromatase inhibitor (176) or fulvestrant (32). Median PFS was 22.8 and 9.5 months respectively; HR 0.32 (95% CI 0.17-0.59). Median OS was not reached in either group; HR 0.22 (95% CI 0.09-0.56). Out of the ER strongly-positive patients (160), those with PR 7-8 did better than those with PR 0-4, with median PFS 28.7 and 14.0 months respectively; HR 0.40 (95% CI 0.22-0.72). Median OS was not reached for PR 7-8, and 31.8 months for PR 0-4. 115 patients received 1 (20%), 2 (13%) or more (12%) subsequent therapies. Patients who received everolimus at any point had better outcomes. Median OS was not reached in the everolimus group, and 28.5 months in the rest; HR 0.22 (95% CI 0.11-0.44). As patients suitable for everolimus may represent a distinct population, a comparison of baseline characteristics is presented [Table 1]. Patients with invasive ductal cancer (IDC) or lobular (ILC) had median PFS 17.1 and 24.2 months respectively; HR 0.69 (95% CI 0.43-1.09). Median OS was not reached in either group; HR 0.54 (95% CI 0.26-1.10). Median number of cycles was 17. Treatment was ongoing in 42% of patients at data cut-off. Dose was reduced in 43% and delayed in 74%. Mean dose intensity was 85%. Reasons for stopping treatment were progressive disease (70%), toxicity (20%) or unrecorded (10%). 60% experienced toxicities of grade 3 or above, or which resulted in dose adjustment. The commonest were neutropenia (38%), diarrhoea (11%) and lethargy (10%). Less frequent were mucositis, nausea, vomiting and anorexia (2% each). Of 68 patients with accessible documentation of radiological response, 41 had partial and 27 had complete response. Conclusions Our outcomes are comparable to those achieved in RCTs, despite poorer baseline characteristics [Table 2]. Our data suggest OS benefit with ribociclib. Predictors of good outcome include subsequent everolimus, strong PR+, strong ER+ and ILC. The prognostic benefit of lobular histology has not been definitively shown elsewhere. Table 1.comparing baseline characteristics between the everolimus subgroup and the restSubsequent therapy included everolimus n=35Subsequent therapy excluded everolimus n=61DemographicsMedian age (range)62 (30-83)58 (34-90)PS 0-1 (%)34 (97%)51 (84%)PS 2-3 (%)1 (3%)8 (13%)Tumour characteristicsLeft-sided breast cancer (%)20 (57%)27 (44%)Right-sided breast cancer (%)10 (29%)25 (41%)Bilateral (%)0 (0%)2 (3%)Data missing (%)5 (14%)7 (11%)Grade 1 (%)1 (3%)1 (2%)Grade 2 (%)17 (49%)24 (39%)Grade 3 (%)10 (29%)24 (39%)Data missing (%)7 (20%)12 (20%)Ductal (%)22 (63%)43 (70%)Lobular (%)8 (23%)7 (11%)Data missing (%)5 (14%)11 (18%)PR 7-817 (49%)18 (30%)ER 7-828 (80%)46 (75%)Visceral disease13 (37%)30 (49%)Metastatic at diagnosis (%)5 (14%)10 (16%)Median metastasis-free interval (range)9.5 years (0-37.7 years)4.6 years (0-36.0 years)Subsequent lines of therapy19 (26%)34 (56%)213 (37%)15 (25%)3 or more13 (37%)12 (20%) Table 2.comparing baseline characteristics between the current study and the key RCTsAuditRCTsMedian age (range)6160PS 0-188%99%PS 2-316%1%Ductal62%38%Lobular16%7%Histology missing22%55%PR 0-418%PR- 12% in 1L, 23% in 2LPR 7-848%PR+ 54% in 1L, 74% in 2LVisceral disease40%49%Bone-only18%23%Metastatic at diagnosis21%34%Not metastatic at diagnosis79%66%Median metastasis-free interval6.9 years51% &amp;gt;12m, 9% &amp;lt;=12m Citation Format: Lei Wang, Muhammad Ibrahim, Anthony Neal. Real-world outcomes with palbociclib, abemaciclib and ribociclib; experience of a tertiary oncology centre in the United Kingdom [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-18-33.

Abstract P2-03-01: Changes in breast cancer presentation during Covid-19: Experience in an Urban Academic Center

Abstract Background: The COVID-19 pandemic strained healthcare systems worldwide, delaying breast cancer screening and surgery. In 2019, approximately 80% of breast cancers in the U.S. were diagnosed on screening examinations, with 76.4% of eligible Medicare patients undergoing screening at least every two years. Since the start of the pandemic, many women have been reluctant to seek elective screening mammography, even with the lifting of “lock-down”. We describe the effect of the COVID-19 pandemic on breast cancer presentation at an academic medical center in a city hit hard by the pandemic. Materials and Methods: The institutional IRB-approved Breast Cancer Registry Database was queried for patients enrolled during two time periods, those undergoing first surgical procedure before the start of the pandemic (4/1/2019-3/31/2020) to those the year after the pandemic started (4/1/2020-3/31/2021). Elective cancer surgery was paused for 3 weeks, ending 4/20/2020, and access to routine breast care was limited for 3 months. Variables included age, method of detection, palpability, histologic subtype and staging, neoadjuvant systemic therapy, cancer specific treatments, and radiation uptake. Results: 349 patients were in the 2019 cohort; 246 in the 2020 cohort. No differences in baseline characteristics, including age at presentation, nodal status, or operation type. Fewer cancers were detected on routine mammography post-COVID vs. pre-COVID. Increase in detection of breast cancer through self-exams in 2020 was seen compared to 2019. Palpability on presentation also increased. More patients were treated with neo-adjuvant therapy chemotherapy, and 36 of 45 (80%) eligible early-stage breast cancer patients accepted neoadjuvant hormonal therapy during the period that elective cancer surgery was on hold. Patients received radiation therapy less frequently during the pandemic. The proportion of patients diagnosed with invasive ductal cancers was higher in the 2020 cohort and the proportion of patients diagnosed with ductal carcinoma in situ (DCIS) and for invasive lobular cancers (ILC) was lower. Conclusions: Patients at an academic New York City medical center presented with more palpable and invasive breast cancers during the COVID-19 pandemic compared to the preceding year, and fewer patients with DCIS and ILC, cancers typically detected following screening mammography. While stage migration with an increase in diagnosis of late stage cancers has been described, in our population the stage shift occurred in early stage breast cancer, with decreases in DCIS and increases in Stages I-II, with the higher stages III-IV essentially unchanged. This reflects the effect of delay in our previously highly-screened population, with an average screening delay of 3 + months, and many patients missing their yearly screening altogether. While many medical interactions during COVID-19 were via telemedicine, radiation therapy requires daily office visits, and fear of exposure contributed to the lower rate of radiation. Given the increase in invasiveness and stage of breast cancers diagnosed during the COVID-19 pandemic, this study emphasizes the importance of screening for diagnosis and treatment of breast cancer, even in the face of a concurrent health crisis. Variable2019 Population N=3492020 Population N=246P-ValueMethod of DetectionSelf-Exam19.80%26.0%0.0688Mammography67.0%60.0%Palpability31.50%39.20%0.0533Neoadjuvant Therapy8.30%10.20%0.4384Radiation Therapy65.0%54%&amp;lt;0.0001Age at presentation60.0460.680.6171Type of surgeryBreast Conserving Surgery69%66%&amp;lt;0.8508Mastectomy31%34%HistologyIDC60.70%66.7%0.5822DCIS20.9%16.7%ILC10.6%8.10% Citation Format: Amber Azniv Guth, Brian Diskin, Freya Schnabel, Nakisa Pourkey, Deborah Axelrod, Richard Shapiro. Changes in breast cancer presentation during Covid-19: Experience in an Urban Academic Center [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-03-01.

EGFR and COX-2 Dual Inhibitor: The Design, Synthesis, and Biological Evaluation of Novel Chalcones

For most researchers, discovering new anticancer drugs to avoid the adverse effects of current ones, to improve therapeutic benefits and to reduce resistance is essential. Because the COX-2 enzyme plays an important role in various types of cancer leading to malignancy enhancement, inhibition of apoptosis, and tumor-cell metastasis, an indispensable objective is to design new scaffolds or drugs that possess combined action or dual effect, such as kinase and COX-2 inhibition. The start compounds A1 to A6 were prepared through the diazo coupling of 3-aminoacetophenone with a corresponding phenol and then condensed with two new chalcone series, C7–18. The newly synthesized compounds were assessed against both COX-2 and epidermal growth factor receptor (EGFR) for their inhibitory effect. All novel compounds were screened for cytotoxicity against five cancer cell lines. Compounds C9 and G10 exhibited potent EGFR inhibition with IC50 values of 0.8 and 1.1 µM, respectively. Additionally, they also displayed great COX-2 inhibition with IC50 values of 1.27 and 1.88 µM, respectively. Furthermore, the target compounds were assessed for their cytotoxicity against pancreatic ductal cancer (Panc-1), lung cancer (H-460), human colon cancer (HT-29), human malignant melanoma (A375) and pancreatic cancer (PaCa-2) cell lines. Interestingly, compounds C10 and G12 exhibited the strongest cytotoxic effect against PaCa-2 with average IC50 values of 0.9 and 0.8 µM, respectively. To understand the possible binding modes of the compounds under investigation with the receptor cites of EGFR and COX-2, a virtual docking study was conducted.

Double face of cytochrome c in cancers by Raman imaging

Cytochrome c (Cyt c) is a key protein that is needed to maintain life (respiration) and cell death (apoptosis). The dual-function of Cyt c comes from its capability to act as mitochondrial redox carrier that transfers electrons between the membrane-embedded complexes III and IV and to serve as a cytoplasmic apoptosis-triggering agent, activating the caspase cascade. However, the precise roles of Cyt c in mitochondria, cytoplasm and extracellular matrix under normal and pathological conditions are not completely understood. To date, no pathway of Cyt c release that results in caspase activation has been compellingly demonstrated in any invertebrate. The significance of mitochondrial dysfunctionality has not been studied in ductal carcinoma to the best of our knowledge. We used Raman spectroscopy and imaging to monitor changes in the redox state of the mitochondrial cytochromes in ex vivo surgically resected specimens of human breast tissues, and in vitro human breast cells of normal cells (MCF 10A), slightly malignant cells (MCF7) and highly aggressive cells (MDA-MB-231). We showed that Raman imaging provides insight into the biology of human breast ductal cancer. Here we show that proper concentration of monounsaturated fatty acids, saturated fatty acids, cardiolipin and Cyt c is critical in the correct breast ductal functioning and constitutes an important parameter to assess breast epithelial cells integrity and homeostasis. We look inside human breast ducts by Raman imaging answering fundamental questions about location and distribution of various biochemical components inside the lumen, epithelial cells of the duct and the extracellular matrix around the cancer duct during cancer development in situ. Our results show that human breast cancers demonstrate a redox imbalance compared to normal tissue. The reduced cytochrome c is upregulated in all stages of cancers development. The results of the paper shed light on a largely non-investigated issues regarding cytochromes and mitochondrial function in electron transfer chain. We found in histopathologically controlled breast cancer duct that Cyt c, cardiolipin, and palmitic acid are the main components inside the lumen of cancerous duct in situ. The presented results show direct evidence that Cyt c is released to the lumen from the epithelial cells in cancerous duct. In contrast the lumen in normal duct is empty and free of Cyt c. Our results demonstrate how Cyt c is likely to function in cancer development. We anticipate our results to be a starting point for more sophisticated in vitro and in vivo animal models. For example, the correlation between concentration of Cyt c and cancer grade could be tested in various types of cancer. Furthermore, Cyt c is a target of anti-cancer drug development and a well-defined and quantitative Raman based assay for oxidative phosphorylation and apoptosis will be relevant for such developments.

Potential Role of Exosomes in the Chemoresistance to Gemcitabine and Nab-Paclitaxel in Pancreatic Cancer.

In recent years, a growing number of studies have evaluated the role of exosomes in pancreatic ductal adenocarcinoma cancer (PDAC) demonstrating their involvement in a multitude of pathways, including the induction of chemoresistance. The aim of this review is to present an overview of the current knowledge on the role of exosomes in the resistance to gemcitabine and nab-paclitaxel, which are two of the most commonly used drugs for the treatment of PDAC patients. Exosomes are vesicular cargos that transport multiple miRNAs, mRNAs and proteins from one cell to another cell and some of these factors can influence specific determinants of gemcitabine activity, such as the nucleoside transporter hENT1, or multidrug resistance proteins involved in the resistance to paclitaxel. Additional mechanisms underlying exosome-mediated resistance include the modulation of apoptotic pathways, cellular metabolism, or the modulation of oncogenic miRNA, such as miR-21 and miR-155. The current status of studies on circulating exosomal miRNA and their possible role as biomarkers are also discussed. Finally, we integrated the preclinical data with emerging clinical evidence, showing how the study of exosomes could help to predict the resistance of individual tumors, and guide the clinicians in the selection of innovative therapeutic strategies to overcome drug resistance.

Genomic alterations drive metastases formation in pancreatic ductal adenocarcinoma cancer: deciphering the role of CDKN2A and CDKN2B in mediating liver tropism.

Metastases are often the direct cause of death from pancreatic ductal adenocarcinoma (PDAC). The role of genomic alterations (GA) in mediating tropism and metastasis formation by PDAC cells is currently unknown. We aimed to identify GAs predisposing colonization of PDAC cells to the liver and decipher mechanisms enabling this process. In order to reveal specific genes, we studied the frequency of GA in 8,880 local and 7,983 metastatic PDAC samples. We observed differential pattern of GA in the local tumor and specific metastatic sites, with liver metastases characterized by deletion of CDKN2A/B (encoding p16/p15, respectively). The role of CDKN2A/B in promoting liver metastasis was evidenced by enhanced tumorigenic phenotype of p15/p16-deleted PDAC cells when exposed to hepatocytes conditioned media. The liver is characterized by high-ammonia low-glutamine environment and transcriptomic assays indicated unique adaptation of PDAC cells to these conditions, including regulation of genes leading to reduced glutaminolysis, like overexpression of GLUL and reduction in GLS2. Furthermore, metabolic assays indicated an increase in glutamate derived from [U-13C]-glucose in p15/p16-deleted cells. Importantly, these cells thrived under high ammonia condition. These data suggest a unique role for genomic alterations in mediating tropism of PDAC. Among these alterations, p15/16 deletion was identified as a promoter of liver metastases. Further studies indicated a unique role for p15/16 in regulating glutaminolysis. These findings reveal vulnerabilities in PDAC cells, which may pave the way for the development of novel therapeutic strategies aiming at the prevention of liver metastases formation.

Survival analysis in patients with invasive lobular cancer and invasive ductal cancer according to hormone receptor expression status in the Korean population.

BackgroundWe compared the clinicopathological characteristics and survival outcomes of invasive lobular carcinoma (ILC) cases with those of invasive ductal carcinoma (IDC) cases in various hormone receptor expression subgroups.MethodsWe compared clinicopathological characteristics, overall survival (OS), and breast cancer-specific survival (BCSS) between patients with IDC (n = 95,486) and ILC (n = 3,023). In addition, we analyzed the effects of different hormone receptor expression subgroups on survival.ResultsThe ILC group had more instances of advanced stage and hormonal receptor positivity than did the IDC group (p < 0.001), but the IDC group had higher histological grade and nuclear grade, as well as higher frequency of human epidermal growth factor receptor 2 and Ki67 expression than did the ILC group (p < 0.001). The OS and BCSS were not significantly different between the IDC and ILC groups. The 5-year OS of the IDC group was 88.8%, while that of the ILC group was 90.6% (p = 0.113). The 5-year BCSS of the IDC group was 94.8%, while that of the ILC group was 95.0% (p = 0.552). When analyzing each hormone receptor expression subgroup, there were no significant differences in survival between the IDC and ILC groups. However, the estrogen receptor (ER) negative/progesterone receptor (PR) negative subgroup showed differences in survival between the IDC and ILC groups. Moreover, the hazard ratio of ILC in the ER negative/PR negative subgroup was 1.345 (95% confidence interval: 1.012–1.788; p = 0.041).ConclusionsHormone receptor expression should be considered when determining prognosis and treatment regimen for IDC and ILC. Researchers should further study the ER negative/PR negative population to identify treatment and prognostic models that will facilitate the development of individualized therapy for these patients, which is needed for good outcomes.

Optimization of Isolation Method for Extracellular Vesicles from Pancreatic Juice and Impact of Protease Activity.

Pancreatic juice (PJ) is directly associated with pancreatic lesions, including pancreatic ductal cancer and intraductal papillary mucinous neoplasm-derived cancer. Therefore, EVs secreted from these lesions into PJ can be promising biomarkers for early diagnosis. However, there are limited data from analysis of EVs in PJ samples. We aimed to determine the stability of EVs in PJ collected using endoscopic naso-pancreatic drainage (ENPD) tubes as well as catheter during endoscopic retrograde cholangiography (ERCP), with or without the impact of positive protease activity, and optimize the EV isolation method. Size exclusion chromatography was found to be an optimal isolation method for EVs in PJ as it achieved higher recovery and purity of EVs compared with differential ultracentrifugation and polymer-based precipitation. Approximately 40% of the PJ samples collected during ERCP and more than 90% of those collected using ENPD tubes had positive protease activity. In vitro exposure to room temperature for less than 3h was harmless to the structure of double-membrane EVs in PJ and the expression levels of TSG101, even with positive protease activity. We clarified the physiobiological status of EVs in PJ and optimized the EV isolation method using suitable PJ samples; these findings can be utilized to discover biomarkers for cancer diagnosis and elucidate their function.

The Expression and Prognostic Significance of Major MicroRNA Genes in Breast Cancer Based on Bioinformatics Analysis

Objective: Breast Cancer (BC) is characterized by high complexity and heterogeneity, and microRNA (miRNA) is bound up with the occurrence and development of BC. In this study, we evaluated the prognostic value of miRNA in BC. Background: Breast ductal and lobular cancers are the most common types of Breast Carcinomas (BC) and indicate the high complexity heterogeneity in this disease. Each BC patient has unique morphological and molecular features. MicroRNAs (miRNAs) play a critical role in human oncogenesis, progression, and prognosis. Our study aimed to identify potential prognostic biomarkers of breast ductal and lobular cancers to predict the overall survival outcome. Methods: All analyzed miRNA sequencing and clinical data were obtained from the Genomic Data Commons Data Porta. edgeR package in R software was used to analyze the differential miRNA expression profiles. Complete survival information and differentially expressed miRNA expression were obtained and the Caret package was used for random division of the samples along with their profiles into two groups (training group and test group). We performed univariate Cox regression analyses for miRNAs in the training group. We utilized three different web-based tools to identify the target genes of miRNAs and used the Perl language to evaluate the target genes for miRNA signature. STRING database was used to assess PPIs. Results: A total of 304 differentially expressed miRNAs were identified (213 were upregulated and 91 were downregulated). Among these, nine (hsa-miR-204-5p, hsa-miR-7706, hsa-miR-1247-3p, hsa-miR-20b-3p, hsa-miR-605-5p, hsa-miR-615-3p, hsa-miR-4652-5p, hsa-miR-9-5p, hsa-miR-2115-5p) miRNAs which remarkably correlated with overall survival rate of BC were performed by Cox regression analysis and miRNA signature risk score built. And then we performed the model of BC patients for three years survival risk, the AUCs of ROC were 0.804, 0.667, and 0.739 in the training, test, and entire groups, respectively. miRNAs were differentially expressed in tumor-related biological processes and pathways by functional enrichment and bioinformatic analysis. Conclusion: The current study provided novel insights into the miRNA-based mRNA network in BC. The nine miRNA and ten hub genes may be independent prognostic signatures for survival prediction in BC patients.

The role of Jagged1 as a dynamic switch of cancer cell plasticity in PDAC assembloids.

Background: Pancreatic ductal adenocarcinoma (PDAC), which commonly relapses due to chemotherapy resistance, has a poor 5-year survival rate (< 10%). The ability of PDAC to dynamically switch between cancer-initiating cell (CIC) and non-CIC states, which is influenced by both internal and external events, has been suggested as a reason for the low drug efficacy. However, cancer cell plasticity using patient-derived PDAC organoids remains poorly understood.Methods: First, we successfully differentiated CICs, which were the main components of PDAC organoids, toward epithelial ductal carcinomas. We further established PDAC assembloids of organoid-derived differentiated ductal cancer cells with endothelial cells (ECs) and autologous immune cells. To investigate the mechanism for PDAC plasticity, we performed single-cell RNA sequencing analysis after culturing the assembloids for 7 days.Results: In the PDAC assembloids, the ECs and immune cells acted as tumor-supporting cells and induced plasticity in the differentiated ductal carcinomas. We also observed that the transcriptome dynamics during PDAC re-programming were related to the WNT/beta-catenin pathway and apoptotic process. Interestingly, we found that WNT5B in the ECs was highly expressed by trans interaction with a JAG1. Furthermore, JAG1 was highly expressed on PDAC during differentiation, and NOTCH1/NOTCH2 were expressed on the ECs at the same time. The WNT5B expression level correlated positively with those of JAG1, NOTCH1, and NOTCH2, and high JAG1 expression correlated with poor survival. Additionally, we experimentally demonstrated that neutralizing JAG1 inhibited cancer cell plasticity.Conclusions: Our results indicate that JAG1 on PDAC plays a critical role in cancer cell plasticity and maintenance of tumor heterogeneity.

Diagnostic performance of breast imaging with ultrasonography, magnetic resonance and mammography in the assessment of residual tumor after neoadjuvant chemotherapy in breast cancer patients

Background/Aim: Following the administration of neoadjuvant chemotherapy (NAC), a complete pathological response (pCR) is seen at rates of up to 50-70% in breast cancer patients, especially in triple-negative (TNBC) and HER-2 enriched subgroups and related to increased pCR rates, studies to predict the pathological response with preoperative evaluation are ongoing. The aim of this study was to investigate the correlation of preoperative imaging in breast cancer patients receiving NAC with the pathological response. Methods: The study, organized as a retrospective cohort study, included 129 breast patients who underwent surgery after NAC between April 2014 and February 2020. The demographic data of the patients, the clinical and radiological findings before and after NAC, operation findings, and the histopathological evaluation results were collected retrospectively from the patient files. The radiological images of the patients were examined by separating into groups of patients with ultrasonography (US), magnetic resonance imaging (MRI), US+MRI, and mammography (MG)+US. The NAC response on preoperative breast US and MG was evaluated according to the RECIST-1.1 system, and the NAC response on MRI with the Goorts et al grading system. In the histopathological examination of operation material, the Miller Payne grading system for breast tissue was used in the determination of NAC response. Results: The mean age of the patients in the study was 49.17 (11.00) years. The vast majority of the patients (87.6%) were diagnosed with invasive ductal cancer, with 27.13% in luminal A, 35.65% in luminal B, 31.0% in HER-2 enriched, and 6.2% in TNBC subgroups. A statistically significant correlation was determined between the pathological response and the US+MRI, MRI, and US+MG groups, with agreement at a moderate level (Kappa: 0.653, P<0.001; Kappa:0.443, P<0.001; Kappa:0.481, P=0.005, respectively). Within all the groups, the group with the highest sensitivity and accuracy were seen to be the patients evaluated with US+MRI (66.67%, 90.91%, respectively). Conclusion: The results of this study demonstrated that there is a correlation between the pathological response and US+MRI, MRI, and US+MG evaluation after NAC. The US+MRI group was found to have the highest sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. When possible, the use of these two imaging methods together in the preoperative evaluation of patients is a successful method in the prediction of pathological response.

Abstract P063: Novel prodrugs coupled with albumin nanoparticle encapsulation improves antitumor effects of the nucleoside analog gemcitabine

Abstract Nucleoside analogs such as gemcitabine have been widely used to treat many solid tumors. Despite their near universal use and well understood mechanisms of action, this class of chemotherapeutic agents has notable shortcomings including rapid metabolism, limited systemic exposure, acquired resistance, and dose-limiting toxicities. Albumin-based nanoparticles offer several advantages for drug delivery including direct tumor targeting, low risk of immunogenicity, and ease of synthesis and manufacturing. We have modified numerous nucleoside drugs of clinical significance to form new prodrugs and use nanoparticle encapsulation in an attempt to improve the therapeutic index of the parent drugs. Different prodrugs of gemcitabine were designed to evade drug resistance mechanisms, and methods were developed to form stable lyophilized nanoparticle formulations. Nanoparticles were characterized by particle size (~40-65 nm) and polydispersity, and dose-dependent effects on the proliferation of human tumor cell lines were compared to the response to the parent drug gemcitabine. To evaluate effects in vivo, nanoparticle formulations were dosed intravenously (IV) to immunocompromised mice bearing patient-derived xenografts (PDx). The prodrug JTX-836 (IC50=0.46 nM) was ~10x more potent against BxPC-3 pancreatic adenocarcinoma cells than the parent gemcitabine (IC50 = 5.2 nM) in vitro. IV dosing of JTX-836 albumin nanoparticle formulation improved tumor growth inhibition in PDx models of both pancreatic ductal adenocarcinoma (CTG-0282 TumorGraft, Champions Oncology) and ovarian cancer (CTG-1180, Champions Oncology) when compared to IV gemcitabine dosing. These results demonstrate the potential for nanoparticle encapsulation of prodrugs to improve the antitumor activity of existing nucleoside analog therapeutics and support continued development of albumin-based delivery of gemcitabine for the treatment of human cancer. Citation Format: Neil Raheja, Jason Kahana, Robin Jackman, Curtis Monnig. Novel prodrugs coupled with albumin nanoparticle encapsulation improves antitumor effects of the nucleoside analog gemcitabine [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P063.

Circulating tumor DNA correlates with tumor burden and predicts outcome in pancreatic cancer irrespective of tumor stage

IntroductionCirculating tumor DNA (ctDNA) represents a promising tool for diagnosis, prognosis and treatment monitoring of several malignancies. Its association with tumor burden in pancreatic ductal cancer (PDAC), especially in localized disease, is not fully explored yet. We aimed to investigate the association of pretherapeutic ctDNA levels in localized and metastatic PDAC with tumor volume and clinical outcomes. Material and methodsLiquid biopsy for ctDNA detection was prospectively obtained from patients with localized or disseminated PDAC prior to either resection or systemic treatment. Detection rates and levels of ctDNA (digital droplet PCR) were correlated to tumor volume, relapse rate and survival. Results60 patients with localized and 47 patients with metastatic PDAC were included. ctDNA was detected in 10% of localized and 57.4% of metastasized PDAC samples. In localized disease, ctDNA detection significantly correlated with the numbers of involved locoregional lymph nodes (p = 0.030). Primary tumor volume did not correlate with ctDNA levels in neither localized (p = 0.573) nor metastasized disease (p = 0.878). In disseminated disease, ctDNA levels correlated with total tumor volume (p = 0.026) and especially with liver metastases volume (p = 0.004), but not with other metastases. Detection of pretherapeutic ctDNA was associated with shorter DFS in localized (3.3 vs. 18.1 months, p = 0.000), whereas ctDNA levels were associated with worse survival in metastatic PDAC (5.7 vs. 7.8 months, p = 0.036). ConclusionctDNA positivity indicates major nodal involvement or even presence of undetected distant metastases associated with early recurrence in localized PDAC. Moreover, it predicts worse clinical outcome in both localized and metastatic disease.

The patient's perspective: a qualitative study of individual experience with decision-making, treatment, and recovery for resectable pancreatic cancer.

Pancreatic ductal adenocarcinoma cancer (PDAC) remains a challenging diagnosis. The likelihood of long-term survival is limited even for patients who undergo maximal medical therapy with systemic chemotherapy and surgical resection. Within this intensive process, there remains limited understanding of patients' pretreatment expectations of PDAC treatment experience and their decision-making process. PDAC patients who underwent chemotherapy and surgical resection were retrospectively identified. Semi-structured phone interviews were completed regarding patient experience with therapy. Qualitative descriptive analysis was performed, and categories, subcategories, and themes were determined. Fifteen patients were interviewed regarding their experience with PDAC treatment. An overall personal disease trajectory experience was identified with two phases. The first phase encompassed the patients' treatment. In this phase, patients expressed a choice, non-choice regarding therapy decisions, viewing therapy as the only option. Misconceptions about the roles of therapies and expected experience of treatment were observed. The second phase focused on life after therapy. Patients reported persistent physical changes secondary to therapy. An overall realistic understanding of the patient's limited prognosis was observed, with patients expressing appreciation of the life time gained as a benefit of treatment. There remains critical areas for improvement in communication and care of patients with PDAC. Physicians should continue to ensure that patient's goals and wishes are respected when making treatment decisions and confirm that patients understand the roles and limitations of prescribed therapies. Additionally, patients continue to have significant physical changes post treatment which should be assessed for and managed as appropriate to maintain quality of life.