Deletions spanning chromosome 5q31.2 are among the most common recurring cytogenetic abnormalities detectable in myelodysplastic syndromes (MDS). Prior genomic studies have suggested that haploinsufficiency of multiple 5q31.2 genes may contribute to MDS pathogenesis. However, this hypothesis has never been formally tested. Therefore, we designed this study to systematically and comprehensively evaluate all 28 chromosome 5q31.2 genes and directly test whether haploinsufficiency of a single 5q31.2 gene may result from a heterozygous nucleotide mutation or microdeletion. We selected paired tumor (bone marrow) and germline (skin) DNA samples from 46 de novo MDS patients (37 without a cytogenetic 5q31.2 deletion) and performed total exonic gene resequencing (479 amplicons) and array comparative genomic hybridization (CGH). We found no somatic nucleotide changes in the 46 MDS samples, and no cytogenetically silent 5q31.2 deletions in 20/20 samples analyzed by array CGH. Twelve novel single nucleotide polymorphisms were discovered. The mRNA levels of 7 genes in the commonly deleted interval were reduced by 50% in CD34+ cells from del(5q) MDS samples, and no gene showed complete loss of expression. Taken together, these data show that small deletions and/or point mutations in individual 5q31.2 genes are not common events in MDS, and implicate haploinsufficiency of multiple genes as the relevant genetic consequence of this common deletion.

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG-IM) or without gemtuzumab ozogamicin (GO) (9 mg/m 2 on Day 8) (FLAG-I) in relapsed/refractory AML. Three-quarters of patients also received concurrent G-CSF. Seventy-one patients were treated, 23 with FLAG-I and 48 with FLAG-IM. The median duration of follow-up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18-70) and 47 years (range 20-68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG-I and FLAG-IM. The complete remission (CR) rate in the FLAG-I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG-IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event-free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG-I over FLAG-IM. The patients who received G-CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P 5 0.026), median EFS (6.2 vs. 3.4 months, P 5 0.010), and OS (8.8 vs. 3.9 months, P 5 0.004) when compared with those who sequentially received G-CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG-I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G-CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol. 84:733-737, 2009. V

The aim of this study was to determine the association between age and stage at diagnosis of breast cancer with the subsequent development of acute myeloid leukemia (AML). The National Cancer Institute’s Surveillance, Epidemiology, and End Results program were analyzed for incidence of second malignancies by age and stage at diagnosis of breast cancer. 420,076 female patients were identified. There was an age dependent risk of a subsequent diagnosis of AML in women younger than 50 years old (RR 4.14; P <0.001) and women 50–64 years old (RR 2.19; P <0.001), but not those 65 and older (RR 1.19; P = 0.123) when compared with the expected incidence of AML. A similar age dependent pattern was observed for second breast and ovarian cancers. There was also a stage dependent increase in risk of subsequent AML in younger women with stage III disease when compared with stage I disease (RR 2.92; P = 0.004), and to a lesser extent in middle age women (RR 2.24; P = 0.029), but not in older women (RR 0.79; P = 0.80).Younger age and stage III disease at the time of breast cancer diagnosis are associated with increased risk of a subsequent diagnosis of AML. This association maybe explained by either greater chemotherapy exposure or an interaction between therapy and genetic predisposition.

PURPOSE Tumor mutational burden (TMB) is a developing biomarker in non–small-cell lung cancer (NSCLC). Little is known regarding differences between TMB and sample location, histology, or other biomarkers. METHODS A total of 3,424 unmatched NSCLC samples, including 2,351 lung adenocarcinomas (LUADs) and 1,073 lung squamous cell carcinomas (LUSCs), underwent profiling, including next-generation sequencing of 592 cancer-related genes, programmed death ligand 1 immunohistochemistry, and TMB. The rate TMB of 10 mutations per megabase (Mb) or greater was compared between primary and metastatic LUAD and LUSC. Molecular alteration frequency was compared at a cutoff of 10 mutations/Mb. RESULTS LUAD metastases were more likely to have a TMB of 10 mutations/Mb or greater compared with primary LUADs (38% v 25%; P < .001), and this difference was most pronounced with brain metastases (61% v 35% for other metastases; P < .001). The median TMB for LUAD brain metastases was 13 mutations/Mb compared with six mutations/Mb for primary LUADs. Variability existed for other LUAD metastasis sites, with adrenal metastases most likely to meet the cutoff of 10 mutations/Mb (51%) and bone metastases least likely to meet the cutoff (19%). TMB was more commonly 10 mutations/Mb or greater for LUSC primary tumors than for LUAD primary tumors (35% v 25%, respectively; P < .001). LUSC metastases were more likely to have a TMB of 10 mutations/Mb or greater than LUSC primary tumors. Poorly differentiated disease was more likely have a TMB of 10 mutations/Mb or greater when stratified by histology and primary tumor or metastasis. Site-specific molecular differences existed at this TMB cutoff including programmed death ligand 1 positivity and STK11 and KRAS mutation rate. CONCLUSION TMB is a site-specific biomarker in NSCLC with important spatial and histologic differences. TMB is more frequently 10 mutations/Mb or greater in LUAD and LUSC metastases and highest in LUAD brain metastases. Along this TMB cutoff, clinically informative distinctions exist in other tumor profiling characteristics. Further investigation is needed to expand on these findings.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of cytokine-driven immune activation. Cardinal features include fever, hemophagocytosis, hepatosplenomegaly, lymphocytic infiltration, and hypercytokinemia that result in multisystem organ dysfunction and failure. Familial HLH is genetically driven, whereas secondary HLH (SHL) is caused by drugs, autoimmune disease, infection, or cancer. SHL is associated with worse outcomes, with a median overall survival typically of less than 1 year. This reflects difficulty in both diagnostic accuracy and in establishing reliable treatments, especially in cases of malignancyinduced SHL, which have significantly worse outcomes. Malignancy-induced HLH is seen almost exclusively with hematologic malignancies, constituting 97% of cases in the literature over the past 2 years. In these situations, the native immune response driven by CD8 T cells produces an overabundance of T helper 1 cytokines, notably interferon-g, tumor necrosis factor-a, and interleukin-6, which establish a positive feedback loop of inflammation, enhancing replication of hematologic malignancies while leaving the host immune system in disarray. In this paper, we present 2 case studies of secondary HLH driven by HM, followed by a review of the literature discussing the cytokines driving HLH, diagnostic criteria, and current treatments used or undergoing investigation. Case 1A previously healthy 34-year-old male presented with progressive malaise, fevers, and abdominal discomfort. He was found to have massive splenomegaly along with pancytopenia and coagulopathy. Initial laboratory studies showed lactate dehydrogenase (LDH) 470 U/L, ferritin 4450 ng/dL, white blood cell count 1.3 3 10 9 /L, platelets 31 3 10 9 /L, hematocrit 22%, and fibrinogen level 130 mg/dL. A bone marrow (BM) biopsy was performed and showed lymphohistiocytic aggregation without hemophagocytosis. The patient underwent splenectomy; pathology showed splenic red pulp congestion and proliferation of sheets of normal histiocytes with marked erythrophagocytosis. No conclusive evidence of B-or T-cell lymphoma was found at that time, although features suggestive of but not diagnostic for T-cell rich diffuse large B-cell lymphoma (DLBCL) were seen in the spleen. The patient subsequently had a positron emission tomography/computed tomography scan and was found to have small hyperactive para-aortic lymph nodes that were not accessible for biopsy. The patient began therapy for HLH with dexamethasone and etoposide for 6 cycles and tolerated it well, with resolution of his laboratory abnormalities and symptoms.A year and a half after initial diagnosis, he presented to the hospital again with back pain and fevers. A computed tomography scan showed multiple retroperitoneal and periaortic lymph nodes along with liver lesions. He was started on dexamethasone and admitted to the hospital. Multiple lymph node biopsies were performed and were inconclusive, possibly from steroid pretreatment. Further evaluation with bilateral BM biopsies reported T-cell rich ...