Citations

Objectives: Survival benefit of combination over single-agent chemotherapy for metastatic pancreatic ductal adenocarcinoma (PDAC) was demonstrated in younger patients in clinical trials. The authors aimed to evaluate whether this survival benefit of combination chemotherapy is present in elderly patients with metastatic PDAC. Materials and Methods: The authors identified elderly patients (age 65 y or older) with stage IV PDAC and extracted available clinical information from a prospectively maintained institutional pancreatic cancer registry from 2007 to 2016. The primary endpoint was overall survival. Cox proportional hazards regression was used for multivariable survival analyses. Survival outcomes for the entire cohort and by age group I (elderly, 65 to 75 y) and age group II (very elderly, older than 75 y) were assessed. Results: A total of 606 patients were included with a median age of 73.8 years. Among them, 239 patients (39%) received combination chemotherapy and 152 patients (25.1%) received single-agent chemotherapy as first-line treatment. Combination chemotherapy was associated with significantly longer median overall survival compared with single-agent chemotherapy (10.9 vs. 7.5 mo, P<0.001) with hazard ratio 0.62 (95% confidence interval, 0.47-0.81; P=0.001) after adjusting for age, sex, comorbidity, Eastern Cooperative Oncology Group (ECOG) performance status, and carbohydrate antigen 19-9 level. Analyses by age groups indicated that very elderly patients (age group II) benefited from combination chemotherapy compared with single-agent chemotherapy with hazard ratio 0.56 (95% confidence interval, 0.31-1; P=0.049), comparable with the age group I (P age-treatment interaction=0.81). Conclusion: Elderly patients, even those older than 75 years, with metastatic PDAC benefited from combination chemotherapy.

PURPOSE In prostate cancer, inactivating CDK12 mutations lead to gene fusion–induced neoantigens and possibly sensitivity to immunotherapy. We aimed to clinically, pathologically, and molecularly characterize CDK12-aberrant prostate cancers. METHODS We conducted a retrospective multicenter study to identify patients with advanced prostate cancer who harbored somatic loss-of-function CDK12 mutations. We used descriptive statistics to characterize their clinical features and therapeutic outcomes (prostate-specific antigen [PSA] responses, progression-free survival [PFS]) to various systemic therapies, including sensitivity to poly (ADP-ribose) polymerase and PD-1 inhibitors. RESULTS Sixty men with at least monoallelic (51.7% biallelic) CDK12 alterations were identified across nine centers. Median age at diagnosis was 60.5 years; 71.7% and 28.3% were white and nonwhite, respectively; 93.3% had Gleason grade group 4-5; 15.4% had ductal/intraductal histology; 53.3% had metastases at diagnosis; and median PSA was 24.0 ng/mL. Of those who underwent primary androgen deprivation therapy for metastatic hormone-sensitive disease (n = 59), 79.7% had a PSA response, and median PFS was 12.3 months. Of those who received first-line abiraterone and enzalutamide for metastatic castration-resistant prostate cancer (mCRPC; n = 34), 41.2% had a PSA response, and median PFS was 5.3 months. Of those who received a first taxane chemotherapy for mCRPC (n = 22), 31.8% had a PSA response, and median PFS was 3.8 months. Eleven men received a PARP inhibitor (olaparib [n = 10], rucaparib [n = 1]), and none had a PSA response (median PFS, 3.6 months). Nine men received a PD-1 inhibitor as fourth- to sixth-line systemic therapy (pembrolizumab [n = 5], nivolumab [n = 4]); 33.3% had a PSA response, and median PFS was 5.4 months. CONCLUSION CDK12-altered prostate cancer is an aggressive subtype with poor outcomes to hormonal and taxane therapies as well as to PARP inhibitors. A proportion of these patients may respond favorably to PD-1 inhibitors, which implicates CDK12 deficiency in immunotherapy sensitivity.

Abstract Vascular smooth muscle cells (VSMCs) in the normal arterial media continually express contractile phenotypic markers which are reduced dramatically in response to injury. Tripartite motif‐containing proteins are a family of scaffold proteins shown to regulate gene silencing, cell growth, and differentiation. We here investigated the biological role of tripartite motif‐containing 28 (TRIM28) and tripartite motif‐containing 27 (TRIM27) in VSMCs. We observed that siRNA‐mediated knockdown of TRIM28 and TRIM27 inhibited platelet‐derived growth factor (PDGF)‐induced migration in human VSMCs. Both TRIM28 and TRIM27 can regulate serum response element activity and were required for maintaining the contractile gene expression in human VSMCs. At the same time, TRIM28 and TRIM27 knockdown reduced the expression of PDGF receptor‐β (PDGFRβ) and the phosphorylation of its downstream signaling components. Immunoprecipitation showed that TRIM28 formed complexes with TRIM27 through its N‐terminal RING‐B boxes‐Coiled‐Coil domain. Furthermore, TRIM28 and TRIM27 were shown to be upregulated and mediate the VSMC contractile marker gene and PDGFRβ expression in differentiating human bone marrow mesenchymal stem cells. In conclusion, we identified that TRIM28 and TRIM27 cooperatively maintain the endogenous expression of PDGFRβ and contractile phenotype of human VSMCs.

Background: Bevacizumab (BEV), a monoclonal antibody against vascular endothelial growth factor-A (VEGF-A), is a standard component of medical therapy of metastatic colorectal cancer (mCRC). Activation of alternative angiogenesis pathways has been implicated in resistance to BEV. This phase II study examines the activity of combined vertical blockade of VEGF signaling with sorafenib and BEV as salvage therapy in patients with progressive disease (PD) on all standard therapy in mCRC. Methods: mCRC patients with documented PD on standard therapy, received sorafenib (200 mg orally twice daily, days 1–5 and 8–12) and BEV (5 mg/kg intravenously, day 1) every 2 weeks. Primary endpoint was 3-month progression-free survival (PFS) rate and secondary endpoints were overall survival (OS), response rate (RR), safety, and feasibility. Results: Of the 83 patients enrolled, 79 were evaluable. Of these, 42 (53%) were progression-free at 3 months. Median PFS was 3.5 months and median OS was 8.3 months. One patient had a partial response and 50 patients (63.3%) had at least one stable tumor assessment. Of 79 evaluable patients, 54 (68%) experienced grade 3/4 adverse events (AEs) at least possibly related to treatment. Most frequent grade 3/4 AEs were: fatigue (24.1%), hypertension (16.5%), elevated lipase (8.9%), hand-foot skin reaction (8.9%), diarrhea (7.6%), and proteinuria (7.6%). Reasons for treatment discontinuation were PD (72%), AEs (18%), patient refusal (8%), physician decision (1%), and death (1%). Conclusions: The combination of BEV and sorafenib as salvage therapy in heavily pretreated mCRC patients is tolerable and manageable, with evidence of promising activity. ClinicalTrials.gov identifier: NCT00826540, URL: http://clinicaltrials.gov/ct2/show/NCT00826540

Introduction: Hypomethylating agents (HMAs) such as decitabine (DEC) or azacitidine (AZA) are FDA approved therapies for patients with different myeloid malignancies as single agent or in combination with venetoclax. Both DEC and AZA require IV infusion for 1 hour or subcutaneous (SC) injections daily for 5-7 days of every 28-day treatment cycle. They both have limited oral bioavailability due to rapid degradation by cytidine deaminase (CDA) in the gut and liver. An orally bioavailable HMA option could reduce clinic visit frequency and reduce infusions/injections related adverse events and burden. ASTX727 is an oral tablet comprised of a fixed-dose combination (FDC) of CDA inhibitor cedazuridine (C) at 100 mg with DEC at 35 mg. In a phase 2 study, C-DEC (ASTX727) demonstrated pharmacokinetic (PK) AUC exposure similar to IV-DEC at 20mg/m2 with comparable clinical activity and safety (Garcia-Manero, et al, 15th Int'l MDS Symposium, 2019). We describe here the results of a phase 3 study designed to demonstrate exposure bioequivalence of oral C-DEC and IV-DEC and generate clinical data using C-DEC in a larger population (ASCERTAIN study). Methods: The study used a randomized cross over design where patients were randomized 1:1 to either Sequence A: C-DEC (100 mg/35 mg respectively) in Cycle 1 followed by IV-DEC at 20 mg/m2 in Cycle 2, or Sequence B receiving IV-DEC in Cycle 1 followed by C-DEC on Cycle 2 to compare PK (primary endpoint AUC equivalence over 5 days of dosing) and pharmacodynamic (PD) of DNA demethylation using LINE-1 assay. All patients received C-DEC in all subsequent cycles from Cycle 3 onwards until treatment discontinuation to study clinical efficacy and safety of C-DEC. Patients were eligible as per the FDA-approved label (MDS IPSS Intermediate [Int]-1,-2 or high risk[HR] and CMML patients). Clinical responses were assessed by an independent expert panel according to International Working Group (IWG) 2006 response criteria. Adverse events (AEs) were graded by Common Terminology Criteria for Adverse Events (CTCAE) v 4.03. Results: 138 patients were randomized, of whom 133 were treated with median age of 71.0 years (range 44-88), median weight was 83.1 kg (range 45-158), and median BSA was 1.99 m2 (range 1.4-2.9 m2). The IPSS status of the patients were Int-1 in 44%, Int-2 in 20%, and HR in 16%, and 12% of pts had CMML. Patients in the two arms were well balanced regarding cytogenetic risk, baseline hemoglobin, neutrophils, platelets, or red blood cell or platelet transfusion dependence. For the primary end point, the decitabine AUC0-24 (h*ng/mL) 5-Day geometric mean estimate was 856 from the C-DEC and 865 from IV-DEC resulting in an oral/IV AUC ratio of 98.9% (90% CI of 92.7-105.6%). All sensitivity and secondary exposure analyses confirmed the primary results. Comparison of hypomethylating activity as measured by LINE-1 demethylation showed difference between oral C-DEC and IV-DEC demethylation of &lt;1% and the 95% CI of the difference included zero. Safety findings were consistent with those anticipated for IV-DEC (related Grade ≥ 3 AEs in more than 5% were thrombocytopenia, neutropenia, anemia, febrile neutropenia, and leukopenia). As of the data cutoff, median follow up was 5.2 months ( IQR 3.5-8.0) with 101 patients evaluable for response . Preliminary response analysis of all evaluable patients showed best responses of complete response (CR) in 12 patients (11.9%), marrow (m)CR in 46 (45.5%) including 14 patients (13.9%) with mCR + hematological improvement (HI), hematologic improvement (HI) in 7 (6.9%) resulting in an objective response rate (CR+mCR+ HI) in 65 patients (64%). In addition, of all 133 treated patients, 16 patients (12%) underwent hematopoietic cell transplant. Updated response data will be presented at the meeting. Summary/Conclusions: This randomized phase 3 study demonstrates that C-DEC, the oral FDC of cedazuridine/decitabine (100 mg/35 mg) resulted in an equivalent DEC exposure to IV-DEC at 20 mg/m2 over 5 days. Safety findings are consistent with those anticipated with IV-DEC with no clinically significant GI toxicity. Preliminary clinical activity is also consistent with published data from IV-DEC. C-DEC is an oral HMA alternative to IV-DEC. Combination studies with other oral agents are being planned. Disclosures Garcia-Manero: Amphivena: Consultancy, Research Funding; Helsinn: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy, Research Funding; Onconova: Research Funding; H3 Biomedicine: Research Funding; Merck: Research Funding. Griffiths:New Link Genetics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Persimmune: Consultancy; Boston Scientific: Consultancy; Genentech, Inc.: Research Funding; Genentech, Inc.: Research Funding; Novartis Inc.: Consultancy; Novartis Inc.: Consultancy; Partner Therapeutics: Consultancy; Astex Phramaceuticals/Otsuka Pharmaceuticals: Consultancy, Research Funding; Onconova Therapeutics: Other: PI on a clinical trial; Celgene, Inc: Consultancy, Research Funding; Abbvie, Inc.: Consultancy; Celgene, Inc: Consultancy, Research Funding; Persimmune: Consultancy; Partner Therapeutics: Consultancy; Boston Scientific: Consultancy; New Link Genetics: Consultancy; Onconova Therapeutics: Other: PI on a clinical trial; Abbvie, Inc.: Consultancy, PI on a clinical trial; Appelis Pharmaceuticals: Other: PI on a clinical trial; Appelis Pharmaceuticals: Other: PI on a clinical trial. Yee:Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Zeidan:Ariad: Honoraria; Acceleron Pharma: Consultancy, Honoraria, Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Otsuka: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Medimmune/AstraZeneca: Research Funding; Astellas: Honoraria; Seattle Genetics: Honoraria; Cardinal Health: Honoraria; Novartis: Honoraria; Agios: Honoraria; Daiichi Sankyo: Honoraria; BeyondSpring: Honoraria; Boehringer-Ingelheim: Consultancy, Honoraria, Research Funding; Trovagene: Consultancy, Honoraria, Research Funding; Incyte: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Research Funding; Jazz: Honoraria. Al-Kali:Astex Pharmaceuticals, Inc.: Research Funding. Dao:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding. Patel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria; France Foundation: Honoraria. Sabloff:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTX: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi Canada: Research Funding; Actinium Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Pfizer Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma Canada: Honoraria, Membership on an entity's Board of Directors or advisory committees. Keating:Sanofi: Membership on an entity's Board of Directors or advisory committees; Hoffman La Roche: Membership on an entity's Board of Directors or advisory committees; Shire: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria. Fazal:Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Gilead: Consultancy, Honoraria, Speakers Bureau; Pfizer: Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Incyte: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy, Honoraria, Speakers Bureau; Celgene: Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau. Odenike:AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Oncology: Research Funding; Astra Zeneca: Research Funding; Gilead Sciences: Research Funding; Agios: Research Funding; CTI/Baxalta: Research Funding; Astex Pharmaceuticals: Research Funding; Incyte: Research Funding; NS Pharma: Research Funding; Oncotherapy: Research Funding. DeZern:Astex Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy. O'Connell:Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Shionogi: Membership on an entity's Board of Directors or advisory committees. Roboz:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees; Otsuka: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Trovagene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Actinium: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amphivena: Consultancy, Membership on an entity's Board of Directors or advisory committees; Argenx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astex: Consultancy, Membership on an entity's Board of Directors or advisory committees. Oganesian:Astex Pharmaceuticals, Inc.: Employment. Hao:Astex Pharmaceuticals, Inc.: Employment. Keer:Astex Pharmaceuticals, Inc.: Employment. Azab:Astex Pharmaceuticals, Inc.: Employment. Savona:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Patents & Royalties; Sunesis: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; Karyopharm Therapeutics: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

PURPOSE: There is a concern that influenza vaccination could increase the incidence of immune-related adverse events (irAEs) in patients with cancer receiving immune checkpoint inhibitors. The aim of our study was to determine the safety of influenza vaccination in this patient population. PATIENTS AND METHODS: We retrospectively identified patients who received at least 1 dose of pembrolizumab during any influenza season from September 2014 to August 2017 and reviewed medical records for irAEs. The primary endpoint was the incidence of irAEs. We used multivariable logistic regression and cumulative incidence curve with competing risks for comparison. RESULTS: Among 162 patients with cancer included in this study, 70 patients (43.2%) received at least 1 influenza vaccination. The vaccinated group was significantly older ( P = .002) and received more cycles of pembrolizumab ( P = .006). The incidence of any grade irAEs in the vaccinated group trended toward being lower (25.7% v 40.2%; P = .07) compared with the nonvaccinated group. Influenza vaccination was independently associated with fewer irAEs, with an odds ratio of 0.4 (95% CI, 0.2 to 0.9; P = .03) in multivariable analyses. The vaccinated group was less likely to have irAEs compared with the nonvaccinated group (24.7% v 34.4% at 12 months; P = .05), with death as a competing risk. The median irAE-free duration in the vaccinated group was longer than the nonvaccinated group (not reached v 28 months; P = .037). CONCLUSION: Influenza vaccination in patients with cancer receiving immune checkpoint inhibitor therapy was not associated with increased irAEs. This supports the safety of influenza vaccination in this patient population.

TPS594 Background: Effective treatment options are very limited for patients with advanced refractory biliary tract cancer (BTC). Fluoropyrimidine-based chemotherapy regimen such as 5-fluorouracil and irinotecan are frequently utilized for these patients after first-line therapy despite lack of FDA approval. Trifluridine/tipiracil (FTD/TPI) is a novel oral nucleoside with antitumor activity in both fluoropyrimidine sensitive and resistant tumors due to its unique mechanisms of action. Given early toxicity and efficacy data from our previous study on single-agent trifluridine/tipiracil (FTD/TPI) in advanced BTC, the clinical evaluation of its combination with irinotecan represents a rational approach for the treatment of advanced refractory BTC. Methods: This is a single-arm phase II trial with a two-stage design to assess the efficacy of trifluridine/tipiracil (FTD/TPI) and irinotecan in advanced refractory BTC. Key eligibility criteria include histologically confirmed advanced, unresectable BTC who have progressed on at least one line of systemic therapy and have measurable disease per RECIST v1.1. Target accrual is 25. Treatment includes trifluridine/tipiracil (FTD/TPI) 25 mg/m2 on days 1-5 and irinotecan 180 mg/m2 on day 1 in 14-day cycles. Patients will be evaluated for response every 4 cycles and in the absence of disease progression, therapy may be given up to 2 years. The primary end point is the progression-free survival rate at 16 weeks. Secondary endpoints include overall response rate, disease control rate, progression-free survival, overall survival, and incidence of adverse events. Correlative biomarker studies include evaluations of circulating tumor DNA and circulating tumor cells at baseline, after 4 cycles and at progression; and development of patient-derived tumor organoids from pre-treatment biopsies for parallel treatments. This study was approved and funded in part by the National Comprehensive Cancer Network (NCCN) Oncology Research Program from general research support provided by Taiho Oncology, Inc. Clinical trial information: NCT 04072445.

571 Background: Tumor-induced generation of splenic erythroblast- like cells (Ter-cells) has been shown to promote tumor progression. These Ter-cells produce the glial-line derived neurotropic factor, ARTN. We investigated the association of pre-operative serum ARTN and the risk of recurrence in HCC patients (pts) undergoing curative resection. Methods: Blood samples were collected prior to surgery as part of an institutional molecular epidemiologic study. Serum ARTN concentration was measured using an enzyme-linked immunosorbent assay (ELISA). Demographics, pathological variables known to be associated with outcomes and clinical outcomes were collected. Uni- and multi-variate analysis were conducted. The optimal cutpoint method was used to define high and low ARTN concentrations. Cox models (hazard ratios, HR) were used to compare progression-free (PFS, primary endpoint), and overall survival (OS) of pts with high vs low serum ARTN. Results: Pre-operative blood samples were available for 58 pts. Median age was 63 years (range: 25-85 years); 74% were male and 50% were Asian. Etiology of liver disease was hepatitis B (43%) and hepatitis C (22%); 43% of tumors were ≤5cm, and vascular invasion was seen in 62%. A baseline alpha-fetoprotein (AFP) of > 100 mcg/L was observed in 36% pts. Median follow-up was 18.9 months. Median ARTN concentration was 0.322 ng/mL. The optimal ARTN concentration cut-off was 0.206 ng/mL. Median PFS for pts with high ( > 0.206 ng/mL) vs low (≤0.206 ng/mL) ARTN was 15.7 vs 55 months (p = 0.04) respectively. Three year PFS was 34% vs 55%, and three year OS 54% vs 91% for high vs low groups. Univariate analysis found that high ARTN concentration (HR 2.44, p = 0.05) and multifocal tumors were associated with a worse PFS. In a multivariate analysis adjusted for AFP > 100mcg/L, vascular invasion, hepatitis status and multifocal tumors, high ARTN remained a negative prognostic factor for PFS, aHR 3.32 (95% CI: 1.22-9.05, p = 0.02). Conclusions: A high pre-surgery serum ARTN is associated with earlier recurrence in HCC pts undergoing curative resection. ARTN should be further studied in HCC to determine its value as a prognostic marker.

Context.— Pulmonary carcinoids are classified as typical or atypical by assessing necrosis and mitoses, which usually cannot be adequately assessed on small biopsies. Ki-67 is not currently used to grade pulmonary carcinoids, but it may be helpful to determine preliminary grade in biopsies. However, the rate at which Ki-67 could underestimate or overestimate grade on small biopsies has not been well studied. Objective.— To compare Ki-67 labeling obtained on small biopsies to subsequent resection. Design.— Ki-67 was performed on paired biopsy and resection specimens from 55 patients. Slides were scanned using Aperio ScanScope. Labeling index was determined using automated hot spot and tumor tracing methods. Results.— The study included 41 typical and 14 atypical carcinoids. Atypical carcinoids were larger and had more distant metastases. Death from disease occurred in 3 patients (all had atypical carcinoids). Median hot spot Ki-67 labeling index was greater in resection compared with biopsy by 0.7% (P = .02). Median tumor tracing Ki-67 was lower in resection compared with biopsy by 0.5% (P &lt; .001). Receiver-operating characteristic analysis showed similar hot spot Ki-67 cutoffs to predict atypical histology (3.5% for biopsy, 3.6% for resection; area under the curve [AUC], 0.75 and 0.74, respectively). Different optimal cutoffs were needed for tracing method based on biopsy (2.1%; AUC, 0.75) compared with resection (1.0%; AUC, 0.67). Conclusions.— Hot spot Ki-67 tends to underestimate grade on small biopsies, whereas grade is overestimated by tumor tracing. Hot spot Ki-67 cutoff of 3.5% predicted atypical histology for both biopsy and resection. Different biopsy and resection cutoffs were necessary for tumor tracing, which would make clinical implementation more difficult.