Citations

Objectives This study sought to better characterize patient characteristics, treatment options, and outcomes for osteoclast-like giant cell carcinoma of the pancreas, a rare subtype of pancreatic adenocarcinoma. Methods This is a retrospective study of all patients with osteoclast-like giant cell carcinoma of pancreatic origin treated at Mayo Clinic from 2000 to present. Baseline patient characteristics, treatment modalities utilized, and outcomes were compiled. Overall survival (OS) and progression-free survival were assessed using Kaplan-Meier analysis with a significance level of P ≤ 0.05. Results Fifteen patients met criteria for inclusion. Four patients had distant metastases at diagnosis, the remaining 11 with locoregional disease. Median OS for the entire cohort was 11 months. Metastatic disease was associated with significantly shorter OS (3.5 vs 14.1 months; P = 0.005). Three patients had no evidence of disease at time of analysis; all 3 were treated with complete resection followed by adjuvant chemotherapy. Conclusions Osteoclast-like giant cell carcinoma of the pancreas is an aggressive malignancy with poor prognosis. For patients with locoregional disease, surgical resection followed by adjuvant chemoradiation may play a role in extended disease-free survival. Metastatic disease presents a challenging entity to treat with little data to support any effective chemotherapy regimens.

Abstract Background:Biliary tract cancers (BTC) are rare, chemo resistant and are associated with a poor prognosis. Preclinical and early clinical work had demonstrated interesting anti-tumor activity from targeting fibroblast growth factor receptor (FGFR) pathway. We hypothesized that ponatinib, a multi-targeted tyrosine kinase inhibitor with activity against FGFR, would be active in BTC patients with FGFR alterations.Methods:This was a multi-center, single institution pilot study of ponatinib in patients with advanced, refractory BTC with FGFR alterations. The primary end point was overall response rate, with secondary points of overall survival (OS), progression-free survival (PFS) and Health Related Quality of Life (HRQoL) assessment. Results:Twelve patients were enrolled prior to early termination of the trial. Clinical benefit (defined as complete/partial response + stable disease) of 45.5% was observed. All observed toxicities were manageable and reversible. Toxicities were mild, with lymphopenia (75%), rash (63%) and fatigue (50%) being the most frequent. No significant detriment in global QoL was observed.Conclusions:Ponatinib as a single agent in FGFR altered BTC is tolerable with very modest clinical activity. This is the first report of prospective assessment of FGFR inhibition in BTC using ponatinib, and the first study to report its effect on HRQoL. Further development of ponatinib will involve correlative studies to better refine patient selection, focus on combinations with other molecular targeted agents, conventional cytotoxic chemotherapy, and studies to better understand mechanisms of treatment resistance.

Abstract Background and Objectives Pancreatic neuroendocrine tumors (pNETs) in patients with hereditary cancer syndromes are typically multifocal. In contrast, sporadic pNETs are usually unifocal and the incidence of multifocal sporadic pNETs is unknown. The primary aim of this study was to investigate the incidence of multifocality in sporadic pNETs and any associated effect on recurrence risk and survival. Methods Patients who underwent resection of pNETs at Mayo Clinic from 2000 to 2019 were identified and clinical data were obtained from medical records. Syndromic disease was defined as pNETs arising in the setting of a hereditary cancer syndrome. Statistical comparisons were made using χ 2 , Fisher's exact, and Kruskal–Wallis tests and survival was assessed using the Kaplan–Meier method. Results Six hundred and sixty‐one patients with sporadic pNETs and fifty‐nine with syndromic pNETs were identified. Multifocal disease was present in 4.8% of sporadic patients and 84.7% of syndromic patients ( p < .001). Within patients with sporadic pNETs, clinicopathologic features and recurrence‐free and overall survival were similar between patients with unifocal and multifocal disease. Conclusions Multifocal sporadic pNETs are rare and multifocality is not associated with worse survival or increased recurrence risk. Patients with multifocal sporadic pNETs can likely be safely managed with a combination of resection and observation as indicated for each tumor.

Abstract Introduction Because of the improved colorectal cancer (CRC) survival in the U.S., patients may live long enough after CRC diagnosis to the point where non–cancer-related comorbidities may considerably impact their overall survival. In this study, we perform a long-term analysis of causes of death (CODs) following nonmetastatic CRC with respect to different demographic and tumor-related criteria. Materials and Methods We gained access to the Surveillance, Epidemiology, and End Results data to review patients diagnosed with nonmetastatic CRC during 2000–2015. We calculated standardized mortality ratios (SMRs) for each COD following CRC. SMRs represented the change of risk of a specific COD following CRC diagnoses when compared with the risk in the general U.S. population. Results We reviewed 302,345 patients, of whom 112,008 died during the study period. More deaths (68.3%) occurred within 5 years following nonmetastatic CRC diagnosis, with 76,486 deaths. CRC was the most common COD (51.4%) within 5 years of diagnosis followed by heart disease (15.2%) and other cancers (8.4%). As time passed after diagnosis, the number of CRC deaths decreased, and other noncancer causes increased to the point that after 10 years only 10.4% of deaths were attributed to CRC, 15.3% were attributed to other cancers, and 34.2% were secondary to heart disease. Conclusion Following nonmetastatic CRC diagnosis, most deaths remain secondary to CRC. Other causes, including other cancers and cardiovascular disease, represent a significant number of deaths, especially in the 5 years following initial CRC diagnosis. Our findings help guide counseling patients with CRC regarding future health risks. Implications for Practice Most common causes of death following nonmetastatic colorectal cancer (CRC) are heart diseases, other cancers, chronic obstructive pulmonary disease, and cerebrovascular diseases. Physicians should counsel patients regarding survivorship with cancer screening and focus on prevention of noncancer deaths. These findings should be considered by physicians who give care for survivors of nonmetastatic CRC.

e16205 Background: Data about neuroendocrine neoplasms (NENs) patients with SARS-CoV-2 are scanty and specific indications for clinical practice are missing. Our aim is to create an international registry about NENs patients affected by SARS-CoV-2 positivity to give a worldwide representation of the situation. Methods: This is an observational retrospective/prospective multicenter survey based on a direct email invitation. All types of NEN are eligible except SCLC and MiNEN. Patients fulfilling the inclusion criteria from March 1st, 2020 up to the end pf pandemic will be recruited. Electronic CRFs are filled out using the REDCap database. Local Institutional Review Board approval is required before data entry. Results: Eighty-one centers, 24 in and 57 outside Italy, representing 39 countries and 5 continents, were contacted. Fourteen centers did not respond and 15 declined the invitation. Among the remaining 52, 6 centers are currently recruiting and 8 are active but not recruiting yet. As of the current abstract submission deadline, 67 patients have been included, mostly GEP-NET (75%), non-functioning (86%), metastatic (85%) and on active treatment [47% somatostatin analogs (SSAs), 10% everolimus, 12% tirosin-kinase inhibitors (TKIs), 10% peptide receptor radionuclide therapy (PRRT), 15% chemotherapy]. Median age at NEN diagnosis was 57 years whilst the median age at SARS-CoV-2 diagnosis was 62 years. Almost all patients reported COVID-19-related symptoms, more commonly fever (67% of patients), cough (55%) and dyspnea (51%), in 28% of cases exertional and in 22% at rest. More than one third of patients (n, 24) had a pneumonia. The most common therapies for COVID-19 were antibiotics, steroids and hydroxychloroquine. Eleven patients (16%) needed oxygen therapy, three (4%) sub-intensive care and none intensive care. Fifty-six patients (84%) clinically recovered, six (9%) with sequelae, whereas five (7%) died. Among these latter 4 had a NET and 1 a NEC, and no patients have been receiving chemotherapy. With regard to the anti-tumor therapy no change occurred in 66% of patients, temporary interruption in 30%, and definitive discontinuation in 3%, 2% missing. Conclusions: Most of the NEN patients completely recovered from COVID-19, in many cases without any anti-tumor therapy adjustment. No clear correlations were observed with type, primary site and treatment of NEN. The recruitment is ongoing.

4130 Background: Circulating cell-free tumor DNA (ctDNA) genomic profiling is an emerging tool for pancreatic cancer. The impact of detected genomic alterations in tumor response to systemic treatments and outcomes is under investigation. Methods: Patients with advanced pancreatic cancer and ctDNA collected at time of initial diagnosis were retrospectively evaluated. Results of ctDNA analysis were correlated with patients’ demographics, systemic treatment response, progression-free survival (PFS) and overall survival (OS). Results: A total of 104 patients were included in the analysis. The mean age was 70.5 years (SD: 8.3), 50% were male, 37% with locally advanced disease and 63% with metastatic disease. Somatic alterations were detected in 84.6 % of the patients, no genetic alterations were detected in 15.4%, and were associated more with locally advanced pancreatic cancer as opposed to metastatic, p = 0.025. 60.6 % of the cohort had ≥ 2 genomic alterations detected. 28% were treated with FOLFIRINOX and 63% with gemcitabine plus nab-paclitaxel as first-line systemic treatment. Patients with any detectable genomic alterations when compared to patients with no detectable variant had worse median PFS (6.2 versus 15.3 months, p = 0.005) and patients with ≥ 2 detectable genomic alterations had worse median PFS (5.6 versus 11.0 months, p < 0.001) and worse median OS (11.5 versus 24.2 months, p = 0.001). KRAS was detected in 62.5% of the patients and was associated with PD to systemic treatments (80.4% vs 19.6%, p = 0.006), worse median PFS (5.8 versus 13.0 months, p < 0.001) and worse median OS (11.5 versus 26.3 months, p = 0.002). TP53 was detected in 60% of patients and was associated with worse median PFS (5.9 versus 10.9 months, p = 0.02) and worse median OS (13.5 versus 24.2 months, p = 0.001). CCND2 was detected in 14% of the patients and was associated with worse median PFS (3.6 versus 8.2 months, p = 0.004). Conclusions: Our study showed that initial detection of ctDNA may identify different genomic alterations that help predict disease outcomes, confirmation of these findings in larger studies are warranted.

4118 Background: Germline variations in cancer susceptibility genes have important implications on treatment and family counseling in pancreatic cancer (PC). We report the prevalence and clinical outcomes of unselected PC patients with pathogenic germline variants (PGV) detected using a universal testing approach. Methods: We undertook a prospective multi-site study of germline sequencing using an >80 gene next-generation sequencing platform among 250 PC patients (not selected for age or family cancer history) between April 1, 2018 and March 31, 2020. Demographic, tumor characteristics and clinical outcomes were compared between PGV carriers and non-carriers. Results: Of 250 patients, the mean age was 65 years (SD 8.7), 56% were male, 83.6% were white and 65.6% had advanced disease (Stage III and IV). PGV were found in 15.2% (N=38) of patients, two patients had more than one PGV. Variants of uncertain significance were found in 44.4% (N=111). Family history of cancer (OR 2.36, 95% CI: 1.14-5.19, p=0.025) was associated with a higher risk of PGV. In a median follow up of 16.5 months, median overall survival was 16.8 months in PGV carriers compared with 16.5 months in non-carriers (HR 0.51, 95 %CI, 0.25-1.01, p=0.05). Higher levels of CA 19-9 and advanced stages (III and IV) were associated with worse outcomes in both groups. Overall, 68% of PGV carriers had mutations in homologous recombination repair (HRR) genes, including BRCA1, BRCA2, PALB2, ATM, CHEK2, NBN, RAD51C. In 65% of HRR gene carrier’s systemic therapy with platinum was used. Conclusions: Universal multi-gene panel testing in pancreatic cancer reveals that 1 in 6 patients are carriers of PGV and is associated with improved survival. Multi-gene germline testing should be used to aid in treatment selection, prognostication, and familial cancer counseling. Distribution of the 40 PGV by penetrance status.[Table: see text]

4079 Background: Cell-free circulating tumor DNA (ctDNA) holds significant promise and is being used for clinical decision making in multiple tumors. This study aimed to evaluate the prognostic value of pre-treatment ctDNA in metastatic biliary tract cancers (BTC) treated with platinum based first-line chemotherapy treatment. Methods: We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis we considered the detected gene with highest variant allele frequency (VAF). Results of ctDNA analysis were correlated with patients’ demographics, progression-free survival (PFS) and overall survival (OS). Results: The median age of patients was 67 y/o (27-90). 54 (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma and six gallbladder cancer. 46 (68.6%) of the patients were treated with cisplatin plus gemcitabine, 14 (21%) patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations while 7 (10.4%) patients were treated on a clinical trial with gemcitabine and cisplatin plus additional targeted agents (CX4945 or PEGPH20). TP53, KRAS, APC, FGFR2 and IDH1 were the genes with highest frequency as dominant clone. The median dominant clone allele frequency (DCAF) was 3% (0-97%). DCAF >3% was associated with statistically significant worse PFS (median PFS: 4.05 vs. 7.70 months, p=0.046) and OS (median OS: 10.8 vs. 18.8 months, p=0.056). Each 1% increase in DCAF is associated with a hazard ratio of 26.21 in OS when adjusting for subtypes, age, treatment type, and CA19-9 [Table]. Conclusions: Patients with metastatic BTC with DCAF > 3% at diagnosis have worse PFS and OS compared to patients with low ctDNA when treated with upfront platinum-based chemotherapy.[Table: see text]

Objectives Checkpoint inhibitors (CPIs) for low- and intermediate-grade neuroendocrine tumors (NETs) have been associated with limited efficacy; recent studies suggest CPIs may represent promising treatment for high-grade neuroendocrine neoplasms (NENs). Methods We examined 57 patients with NENs who were treated with CPIs to determine if NETs and neuroendocrine carcinomas (NECs) respond to immunotherapy. Results Patients with poorly differentiated NECs on CPI monotherapy had an objective response rate (ORR) of 0% and median progression-free survival (PFS) of 2.1 months (95% confidence interval [CI], 0.5–4.6). Patients with poorly differentiated NECs on dual CPI therapy had an ORR of 13% and PFS of 3.5 months (95% CI, 1.4–not reached [NR]). Patients with poorly differentiated NECs on CPI and cytotoxic therapy had an ORR of 36% with PFS of 4.2 months (95% CI, 1.6–NR). Well-differentiated grade 1 and 2 NETs on CPI monotherapy had an ORR of 25% with PFS NR. Well-differentiated grade 3 NETs had 0% ORR with a PFS of 2.9 months (95% CI, 1.4–4.2) on CPI monotherapy. Conclusions Checkpoint inhibitor therapy shows limited activity in patients with NENs. Future studies should identify biomarkers that can help identify patients who are likely responders to immunotherapy.