Pham, Anthony

Abstract INTRODUCTION: Adult mature T- and NK-cell neoplasms are a heterogeneous group of aggressive lymphomas comprising approximately 10% to 20% of all non-Hodgkin lymphomas (NHL) with an estimated 5-year overall survival of 40%. Staging and treatment strategies are guided by malignant involvement on PET/CT scan and bone marrow (BM) biopsy. The Lugano Criteria, established in 2014, suggested that focal FDG uptake within the bone marrow was highly sensitive for both Hodgkin (HL) and diffuse large B-cell lymphoma (DLBCL) potentially obviating the need for a bone marrow biopsy if no lesions were seen. Limited data exist regarding the sensitivity of PET for BM involvement in T-cell lymphoma. This study compares PET/CT scans and repeat BM biopsy in patients who have undergone treatment for peripheral T-cell lymphomas (PTCL) by evaluating BM avidity on PET scans. METHODS: This is a single institution study using the Mayo Clinic Lymphoma Database between January 1, 2001 and January 1, 2015. We retrospectively identified all patients with a diagnosis of PTCL, biopsy proven BM involvement at diagnosis, and a concomitant PET for staging. Patients were then reviewed to assess completion of induction therapy and availability of both PET/CT and bone marrow results post-therapy. Evaluation for concordance and discordant BM involvement were then determined using BM biopsy as the gold standard. RESULTS: Sixteen patients had both PET/CT and BM biopsy after completing induction therapy. Median age at diagnosis was 63 years (range 34-72) and 69% were male. PTCL subtype was peripheral T-cell lymphoma, not otherwise specified in seven patients; ALK negative anaplastic large cell lymphoma in one patient; and angioimmunoblastic in 8 patients. Pre-treatment PET/CT scans demonstrated eight patients (50%) with false negative scans. Post-treatment biopsy results demonstrated that ten (62.5%) had biopsy proven residual bone marrow involvement after induction. Eight patients (50%) were found to have BM biopsy proven disease with a negative PET scan. Two patients (12.5%) had both positive BM biopsy and PET scans; 5 patients (31.3%) had negative BM biopsies and PET scans. One patient (6.25%) had a negative BM biopsy, but had a PET scan that revealed positive disease. This patient was considered to have had a false positive PET scan and indeed has remained in remission since April 2009 without any further relapse or treatment. Sensitivity of PET for BM involvement was very poor at 20% (2/10) with a specificity of 50% (2/4) (Table 1 and 2). CONCLUSIONS: This study in PTCL indicates that PET scans at the completion of therapy have a 50% false negative rate. These patients should not be assumed to have negative bone marrow involvement based solely on PET/CT scans. A bone marrow biopsy at the end of therapy is necessary in PTCL patients to confirm complete response. Table 1. Bone Marrow Involvement Pre-Therapy PET Scan Imaging PET Negative PET Positive Total Patients Bone Marrow Negative NA NA NA Bone Marrow Positive 8 8 16 Total Patients 8 (50%) 8 (50%) 16 Abbreviations: NA, not applicable. The study defined that all patients had to have a positive bone marrow at baseline to be eligible for the study. Table 2. Bone Marrow Involvement PET Negative PET Positive Total Patients Bone Marrow Negative 4 2 6 (37.5%) Bone Marrow Positive 8 2 10 (62.5%) Total Patients 12 (75%) 4 (25%) 16 Table 1 and 2. Involvement of bone marrow with peripheral T-cell lymphoma based on evaluation by PET scans versus bone marrow biopsy. Disclosures Maurer: Kite Pharma: Research Funding.

Abstract INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder caused by the pathologic activation of the immune system. In children, either a molecular diagnosis consistent with HLH or five out of the following eight criteria are considered necessary for a diagnosis of HLH (HLH-04 criteria): 1) fever; 2) splenomegaly; 3) cytopenia in two or more cell lines; 4) hypertriglyceridemia (≥265 mg/dL) or hypofibrinogenemia (≤150 mg/dL); 5) hemophagocytosis in the bone marrow, spleen, or lymph nodes; 6) hyperferritinemia (≥500 mcg/L); 7) impaired NK cell function; and 8) elevated soluble CD25 (sCD25). These criteria have been extrapolated to diagnose HLH in adults; however, it's unclear if these same criteria are applicable in the adult population. METHODS: We reviewed the Mayo Clinic electronic medical record for all adult (≥18 years) hospitalized patients with an admission serum ferritin of ≥500 mcg/L from January 2012 through December 2014. Patients' charts were reviewed and those who met the HLH-04 criteria were considered to have HLH. For the remainder of the patients, the etiology for hyperferritinemia was determined based on chart review and discharge diagnoses. Logistic regression models were used to assess the ability of these values in predicting a diagnosis of HLH. The Mayo Clinic IRB approved this study. RESULTS: We identified 1,329 patients with a serum ferritin ≥500 mcg/L. Of these, HLH was diagnosed in 28 (2.1%) patients (malignancy-associated HLH in 11 patients, infection-associated HLH in 4 patients, autoimmune-associated HLH in 7 patients, and idiopathic HLH in 6 patients). Table 1 describes the etiology of hyperferritinemia in the remaining 1,301 patients. In contrast to pediatric hospitalized patients (Allen, Pediatr Blood Cancer, 2008), adults are more likely to have malignancy (28.1% vs 7%; p<0.05); bacterial infection (21% vs. 13%; p=0.001); liver disease (9.9% vs. 2.7%; p<0.05); and cardiac disease (7.2% vs. 1.5%; p=0.0001) as the etiology of hyperferritinemia during their hospitalization. Among all patients in the study, the following variables were associated with higher odds of having HLH compared to hyperferritinemia due to an alternate cause: elevated ferritin (odds ratio [OR] 35.97, p<0.01); thrombocytopenia (OR 15.22, p<0.01), cytopenias defined by HLH-04 criteria (OR 8.04, p<0.01); elevated admission serum bilirubin (OR 1.05, p=0.02); and peak serum bilirubin (OR 1.05, p<0.01). After stepwise selection in multivariate analysis, serum ferritin ≥2,600 mcg/L and platelets ≤100 x 109/L were independently associated with HLH diagnosis (OR 24.9 and 7.8 respectively; p<0.01 for both). The area under the curve (AUC or c-statistic) ranges from 0.5 for no ability to discriminate, to 1.0 for perfect discrimination; this model has an AUC of 0.91, which shows very good discrimination between cases and controls. An adult hospitalized patient with a combination of serum ferritin ≥2,600 mcg/L and platelets ≤100x109/L predicts a ~200 fold increased likelihood of being diagnosed with HLH as compared to hospitalized adult meeting neither of these criteria (Figures 1 and 2). CONCLUSION: In contrast to hospitalized pediatric patients, the etiology of hyperferritinemia in adults is more likely to be malignancy, bacterial infection, liver disease, and cardiac disease. We conclude that a combination of serum ferritin ≥2,600 mcg/L and platelet count ≤100 x 109/L can be used as screening criteria to help identify adult patients most likely to have HLH. The traditional 5/8 criteria to diagnose HLH in pediatric patients do not appear necessary for establishing a diagnosis of HLH in adult patients. These observations need replication in an independent data set prior to broader applicability. Table 1.Patients with ferritin > 500 mcg/L with underlying cause for elevation.Number Diagnosed (%)Cardiac Disease95 (7.2%)Liver Disease131 (9.9%)Renal Disease87 (6.6%)Infectious343 (25.8%)Malignancy373 (28.1%)Autoimmune118 (8.9%)Solid Organ Transplant34 (2.6%)Stem Cell Transplant16 (1.2%)Bone Marrow Failure9 (0.7%)Shock39 (2.9%)Idiopathic53 (4.0%)Hemoglobinopathies3 (0.2%) Figure 1. ROC curve for the multivariable model with ferritin > 2,600 (yes/no) and platelets below 100,000 (yes/no) in the model with a very good discrimination c-statistic of 0.91. Figure 1. ROC curve for the multivariable model with ferritin > 2,600 (yes/no) and platelets below 100,000 (yes/no) in the model with a very good discrimination c-statistic of 0.91. Figure 2. Figure 2. Disclosures No relevant conflicts of interest to declare.

SummaryHistological transformation (HT) of follicular lymphoma (FL) to an aggressive lymphoma after chemotherapy remains a key issue. The incidence of HT after radioimmunotherapy (RIT) is unknown. This single institution study analysed the risk of HT in FL after treatment with yttrium‐90 ibritumomab tiuxetan in 115 consecutive patients treated during 1987–2012. RIT was administered for progressive FL in 111 (97%) patients and as first‐line therapy in the remaining 4. 28% (n = 32) had HT, occurring at a median of 60 months from diagnosis and 20 months after RIT. 48% (12/25) of patients who received fludarabine developed HT. The estimated 10‐year risk of HT in the fludarabine and non‐fludarabine groups was 67% and 26% respectively (P = 0·015). Only prior fludarabine was significantly associated with predicting the risk of HT after RIT. 8% (9/115) of patients developed therapy‐related myelodysplastic syndrome/acute myeloid leukaemia (tMDS/AML) at a median of 41·4 months (range, 5–89). The estimated 10‐year risk of tMDS/AML in non‐fludarabine treated patients (n = 90) versus fludarabine treated (n = 25) was 13% and 29%, respectively. The estimated overall risk of FL undergoing HT at 10 years without fludarabine exposure appears similar to patients reported in the literature that have not received RIT. Patients with prior purine‐analogue therapy are at significantly higher risk of HT.

Uveal melanoma is a rare type of melanoma, with only five to seven cases per one million persons diagnosed each year. Patients with metastatic melanoma of uveal origin tend to have lower response rates on traditional therapies. Herein we report our experience with 10 patients with metastatic uveal melanoma (MUM) who received pembrolizumab. Eligible patients were more than or equal to 18 years old, had unresectable MUM, progressed on prior ipilimumab therapy, had good performance status (Eastern Cooperative Oncology Group of 0 or 1), and adequate organ and marrow function. Patients could have central nervous system disease, but needed to be clinically stable. Patients were treated with 2 mg/kg pembrolizumab intravenously over 30 min every 3 weeks until disease progression, unacceptable toxicity, or for up to 2 years. Between April 2014 and October 2014, we treated a total of 10 patients with MUM with pembrolizumab. Median age was 65 years, with 70% being female. As of the data cutoff date of 14 May 2015, median progression-free survival was 18 weeks (range 3.14–49.3 weeks), with four patients still currently receiving therapy. Of eight evaluable patients, there was one complete response, two partial responses, and one patient with stable disease. Four patients had rapidly progressive disease. Toxicities were as expected and were usually grade 1/2 in nature. Although this cohort of patients was small, to our knowledge this is the first such report of outcomes in uveal melanoma patients being treated with anti-PD1 therapy. In the absence of a clinical trial, treatment with pembrolizumab appears to be a viable option for patients with MUM.