Rchimerism: An R Package for Automated Chimerism Data Analysis.

A quantitative chimerism test monitors engraftment of donor hematopoietic stem cells or relapse of leukemias or lymphomas in hematopoietic stem cell transplantation patients. The most common method used for chimerism testing is PCR amplification of short tandem repeat loci, followed by capillary gel electrophoresis. Manual data analysis is tedious and time consuming, as it involves the selection of informative loci and the repetition of quantifying chimerism percentage for multiple loci from multiple cell types. It is also susceptible to human errors. Currently, there is no free software to fully automate chimerism data analysis. Rchimerism, an R shiny package, was developed to automatically pick informative loci, calculate chimerism percentage, and display the results through a user-friendly interface. The accuracy of the program was compared with manual calculation on 60 patient samples with 100% concordance. Compared with manual calculation, Rchimerism drastically reduces analysis time from 20 to 40 minutes for single donor transplantation samples and from 40 to 80 minutes for double donor transplantation samples to >1 minute. Rchimerism can be downloaded and used freely by noncommercial laboratories.

Association of Broad-Based Genomic Sequencing With Survival Among Patients With Advanced Non-Small Cell Lung Cancer in the Community Oncology Setting.

Importance: Broad-based genomic sequencing is being used more frequently for patients with advanced non-small cell lung cancer (NSCLC). However, little is known about the association between broad-based genomic sequencing and treatment selection or survival among patients with advanced NSCLC in a community oncology setting. Objective: To compare clinical outcomes between patients with advanced NSCLC who received broad-based genomic sequencing vs a control group of patients who received routine testing for EGFR mutations and/or ALK rearrangements alone. Design, Setting, and Participants: Retrospective cohort study of patients with chart-confirmed advanced NSCLC between January 1, 2011, and July 31, 2016, and who received care at 1 of 191 oncology practices across the United States using the Flatiron Health Database. Patients were diagnosed with stage IIIB/IV or unresectable nonsquamous NSCLC who received at least 1 line of antineoplastic treatment. Exposures: Receipt of either broad-based genomic sequencing or routine testing (EGFR and/or ALK only). Broad-based genomic sequencing included any multigene panel sequencing assay examining more than 30 genes prior to third-line treatment. Main Outcomes and Measures: Primary outcomes were 12-month mortality and overall survival from the start of first-line treatment. Secondary outcomes included frequency of genetic alterations and treatments received. Results: Among 5688 individuals with advanced NSCLC (median age, 67 years [interquartile range, 41-85], 63.6% white, 80% with a history of smoking); 875 (15.4%) received broad-based genomic sequencing and 4813 (84.6%) received routine testing. Among patients who received broad-based genomic sequencing, 4.5% received targeted treatment based on testing results, 9.8% received routine EGFR/ALK targeted treatment, and 85.1% received no targeted treatment. Unadjusted mortality rates at 12 months were 49.2% for patients undergoing broad-based genomic sequencing and 35.9% for patients undergoing routine testing. Using an instrumental variable analysis, there was no significant association between broad-based genomic sequencing and 12-month mortality (predicted probability of death at 12 months, 41.1% for broad-based genomic sequencing vs 44.4% for routine testing; difference -3.6% [95% CI, -18.4% to 11.1%]; P = .63). The results were consistent in the propensity score-matched survival analysis (42.0% vs 45.1%; hazard ratio, 0.92 [95% CI, 0.73 to 1.11]; P = .40) vs unmatched cohort (hazard ratio, 0.69 [95% CI, 0.62 to 0.77]; log-rank P < .001). Conclusions and Relevance: Among patients with advanced non-small cell lung cancer receiving care in the community oncology setting, broad-based genomic sequencing directly informed treatment in a minority of patients and was not independently associated with better survival.

Molecular Analysis of Genetic Markers for Non-Hodgkin Lymphomas.

Molecular analysis complements the clinical and histopathologic tools used to diagnose and subclassify hematologic malignancies. The presence of clonal antigen-receptor gene rearrangements can help to confirm the diagnosis of a B or T cell lymphoma and can serve as a fingerprint of that neoplasm to be used in identifying concurrent disease at disparate sites or recurrence at future time points. Certain lymphoid malignancies harbor a characteristic chromosomal translocation, a finding that may have significant implications for an individual's prognosis or response to therapy. The polymerase chain reaction (PCR) is typically used to detect antigen-receptor gene rearrangements as well as specific translocations that can be supplemented by fluorescence in situ hybridization (FISH) and karyotype analysis. © 2017 by John Wiley & Sons, Inc.

Molecular Analysis of Gene Rearrangements and Mutations in Acute Leukemias and Myeloid Neoplasms.

A subset of acute leukemias and other myeloid neoplasms contains specific genetic alterations, many of which are associated with unique clinical and pathologic features. These alterations include chromosomal rearrangements leading to oncogenic fusion proteins or alteration of gene expression by juxtaposing oncogenes to enhancer elements, as well as mutations leading to aberrant activation of a variety of proteins critical to hematopoietic progenitor cell proliferation and differentiation. Molecular analysis is central to diagnosis and clinical management of leukemias, permitting genetic confirmation of a clinical and histologic impression, providing prognostic and predictive information, and facilitating detection of minimal residual disease. This unit will outline approaches to the molecular diagnosis of the most frequent and clinically relevant genetic alterations in acute leukemias and myeloid neoplasms. © 2017 by John Wiley & Sons, Inc.

Development and clinical application of an integrative genomic approach to personalized cancer therapy.

BACKGROUND: Personalized therapy provides the best outcome of cancer care and its implementation in the clinic has been greatly facilitated by recent convergence of enormous progress in basic cancer research, rapid advancement of new tumor profiling technologies, and an expanding compendium of targeted cancer therapeutics. METHODS: We developed a personalized cancer therapy (PCT) program in a clinical setting, using an integrative genomics approach to fully characterize the complexity of each tumor. We carried out whole exome sequencing (WES) and single-nucleotide polymorphism (SNP) microarray genotyping on DNA from tumor and patient-matched normal specimens, as well as RNA sequencing (RNA-Seq) on available frozen specimens, to identify somatic (tumor-specific) mutations, copy number alterations (CNAs), gene expression changes, gene fusions, and also germline variants. To provide high sensitivity in known cancer mutation hotspots, Ion AmpliSeq Cancer Hotspot Panel v2 (CHPv2) was also employed. We integrated the resulting data with cancer knowledge bases and developed a specific workflow for each cancer type to improve interpretation of genomic data. RESULTS: We returned genomics findings to 46 patients and their physicians describing somatic alterations and predicting drug response, toxicity, and prognosis. Mean 17.3 cancer-relevant somatic mutations per patient were identified, 13.3-fold, 6.9-fold, and 4.7-fold more than could have been detected using CHPv2, Oncomine Cancer Panel (OCP), and FoundationOne, respectively. Our approach delineated the underlying genetic drivers at the pathway level and provided meaningful predictions of therapeutic efficacy and toxicity. Actionable alterations were found in 91 % of patients (mean 4.9 per patient, including somatic mutations, copy number alterations, gene expression alterations, and germline variants), a 7.5-fold, 2.0-fold, and 1.9-fold increase over what could have been uncovered by CHPv2, OCP, and FoundationOne, respectively. The findings altered the course of treatment in four cases. CONCLUSIONS: These results show that a comprehensive, integrative genomic approach as outlined above significantly enhanced genomics-based PCT strategies.

Advocacy and perfect storms: an interview with Janina Longtine, President of the AMP.

Interview with Professor Janina Longtine PhD, by Claire Raison (Commissioning Editor) Janina Longtine is a professor of pathology at the Mount Sinai Hospital (New York, NY, USA) and currently serves as the President of the Association for Molecular Pathology (Bethesda, MD, USA). Prior to this, Professor Longtine was with the Brigham and Women's Hospital (Boston, MA, USA) for 30 years, working on understanding the molecular pathology of cancer and developing diagnostic procedures for cancers. In this interview article to mark 15 years of Expert Review of Molecular Diagnostics, she reflects on her experience as a molecular pathologist in US hospitals, and warns of the regulatory and reimbursement challenges that face laboratory-developed procedures today.

Filter Paper-based Nucleic Acid Storage in High-throughput Solid Tumor Genotyping.

Molecular testing of tumors from formalin-fixed paraffin-embedded (FFPE) tissue blocks is central to clinical practice; however, it requires histology support and increases test turnaround time. Prospective fresh frozen tissue collection requires special handling, additional storage space, and may not be feasible for small specimens. Filter paper-based collection of tumor DNA reduces the need for histology support, requires little storage space, and preserves high-quality nucleic acid. We investigated the performance of tumor smears on filter paper in solid tumor genotyping, as compared with paired FFPE samples. Whatman FTA Micro Card (FTA preps) smears were prepared from 21 fresh tumor samples. A corresponding cytology smear was used to assess tumor cellularity and necrosis. DNA was isolated from FTA preps and FFPE core samples using automated methods and quantified using SYBR green dsDNA detection. Samples were genotyped for 471 mutations on a mass spectrophotometry-based platform (Sequenom). DNA concentrations from FTA preps and FFPE correlated for untreated carcinomas but not for mesenchymal tumors (Spearman σ=0.39 and σ=-0.1, respectively). Average DNA concentrations were lower from FTA preps as compared with FFPE, but DNA quality was higher with less fragmentation. Seventy-six percent of FTA preps and 86% of FFPE samples generated adequate DNA for genotyping. FTA preps tended to perform poorly for collection of DNA from pretreated carcinomas and mesenchymal neoplasms. Of the 16 paired DNA samples that were genotyped, 15 (94%) gave entirely concordant results. Filter paper-based sample preservation is a feasible alternative to FFPE for use in automated, high-throughput genotyping of carcinomas.

Prospective enterprise-level molecular genotyping of a cohort of cancer patients.

Ongoing cancer genome characterization studies continue to elucidate the spectrum of genomic abnormalities that drive many cancers, and in the clinical arena assessment of the driver genetic alterations in patients is playing an increasingly important diagnostic and/or prognostic role for many cancer types. However, the landscape of genomic abnormalities is still unknown for less common cancers, and the influence of specific genotypes on clinical behavior is often still unclear. To address some of these deficiencies, we developed Profile, a prospective cohort study to obtain genomic information on all patients at a large tertiary care medical center for cancer-related care. We enrolled patients with any cancer diagnosis, and, for each patient (unselected for cancer site or type) we applied mass spectrometric genotyping (OncoMap) of 471 common recurrent mutations in 41 cancer-related genes. We report the results of the first 5000 patients, of which 26% exhibited potentially actionable somatic mutations. These observations indicate the utility of genotyping in advancing the field of precision oncology.

Human papillomavirus vaccination and cervical cytology in young minority women.

BACKGROUND: Continued surveillance of human papillomavirus (HPV) vaccination is necessary to identify clinical benefits, particularly given the low rate of vaccine uptake and completion and vaccination of many young women after sexual debut. We studied the effect of catch-up HPV vaccination on cervical cytology and HPV infection in sexually active, low-income and minority young women. METHODS: We conducted a cross-sectional study of 235 women aged 21 to 30 years undergoing routine cervical cytology testing. Demographic and behavioral characteristics were self-reported. HPV vaccination status was determined by self-report and verified with electronic medical records. Liquid-based cytology samples were tested for HPV genotypes. Adjusted prevalence ratios between HPV vaccination and (1) abnormal cervical cytology result and (2) HPV genotype were estimated. FINDINGS: At the time of the study, 96 women (41%) had received at least 1 HPV vaccination, 54 of whom had completed the series; 97% of women were vaccinated after sexual debut. Twenty-four (10%) women had an abnormal cervical cytology result. The prevalence of abnormal cytology was 65% lower in women who received at least 1 HPV vaccination versus unvaccinated women (adjusted prevalence ratio, 0.35; 95% confidence interval, 0.14-0.89). Among 232 women with genotype results, 46 (20%; 95% confidence interval, 15%-26%) had HPV infection detected. HPV types 16, 18, 45, 53, and 66 were most prevalent. CONCLUSIONS: The prevalence of abnormal cytology was lower in vaccinated versus unvaccinated women, despite receipt of vaccination after sexual debut. Continued assessment of HPV vaccine effectiveness before and after sexual debut on HPV infection and cervical dysplasia is needed.

Laboratory practice guidelines for detecting and reporting JAK2 and MPL mutations in myeloproliferative neoplasms: a report of the Association for Molecular Pathology.

Recurrent mutations in JAK2 and MPL genes are genetic hallmarks of BCR-ABL1-negative myeloproliferative neoplasms. Detection of JAK2 and MPL mutations has been incorporated into routine diagnostic algorithms for these diseases. This Special Article summarizes results from a nationwide laboratory survey of JAK2 and MPL mutation analysis. Based on the current practice pattern and the literature, this Special Article provides recommendations and guidelines for laboratory practice for detection of mutations in the JAK2 and MPL genes, including clinical manifestations for prompting the mutation analysis, current and recommended methodologies for testing the mutations, and standardization for reporting the test results. This Special Article also points to future directions for genomic testing in BCR-ABL1-negative myeloproliferative neoplasms.

Intestinal-type endocervical adenocarcinoma in situ: an immunophenotypically distinct subset of AIS affecting older women.

Conventional endocervical adenocarcinoma in situ (cAIS) is typically strongly and diffusely positive for p16 with a high Ki67 index consistent with its frequent association with high-risk human papillomavirus (HPV) infection. The intestinal variant (iAIS) is less common, and its relationship to HPV infection has not been thoroughly examined. This study compares the clinicopathologic features, frequency of HPV infection, and expression of CDX2 and surrogate biomarkers of HPV infection (p16, Ki67) in cAIS with those of iAIS. A total of 86 cases with a diagnosis of AIS (49 iAIS, 37 cAIS) were identified from our multi-institutional files. Of these, 13 iAIS and 20 cAIS cases had slides and tissue available for histopathologic review, immunohistochemical analysis, and molecular tests. All 86 cases were used to evaluate clinical parameters; however, HPV DNA analysis and immunohistochemical analysis for p16, MIB-1, CDX2, and p53 were performed only on those cases with available slides or paraffin blocks. The average age at diagnosis was significantly higher in iAIS compared with that in cAIS (44.5 vs. 32.6 y) (P=0.0001). All 20 cAIS cases showed moderate to strong and diffuse p16 staining; however, only 9/13 iAIS cases showed this degree of p16 staining, whereas 4/13 (31%) iAIS cases showed weak and patchy distribution (P<0.02). Only 6/9 (67%) iAIS cases were positive for either HPV type 18 (5) or 33 (1), in contrast to 11/11 conventional cAIS (P=0.04). Similarly, 12/14 cAIS, but only 5/13 iAIS, cases showed a high Ki67 proliferative index. CDX2 was positive in all iAIS cases, whereas p53 was negative. Most iAIS cases are positive for high-risk HPV and show moderate to strong and diffuse p16 staining; however, a subset of iAIS shows variable staining with p16 and Ki67, is not associated with HPV, and occurs in a distinctly older age group suggesting an alternative pathogenesis. Awareness that iAIS can show variable staining for p16 and Ki67 is important when resolving problematic endocervical lesions, particularly in small biopsies with unusual p16 staining patterns.

No evidence for interference of h&e staining in DNA testing: usefulness of DNA extraction from H&E-stained archival tissue sections.

Although histochemical staining has been believed to inhibit the DNA amplification reaction, no previous study has systematically evaluated the influence of histochemical staining on downstream molecular assays. To evaluate an influence of H&E staining on DNA testing, we isolated DNA from 10 unstained, 10 hematoxylin-stained, 10 eosin-stained, and 10 H&E-stained tissue sections (ie, 4 groups), from each of 5 colon cancers. Among the 4 groups, we did not observe any significant or appreciable difference in DNA fragmentation by agarose gel electrophoresis, in DNA amplification by real-time polymerase chain reaction (PCR), in microsatellite PCR fragment analyses, or in a PCR-pyrosequencing assay. As a proof-of-principle study, we successfully performed microsatellite instability analysis and sequencing of KRAS and BRAF on more than 1,300 colorectal cancers using DNA extracted from H&E-stained tissue sections. Our data provide no evidence for an interfering effect of H&E staining on DNA testing, suggesting that DNA from H&E-stained sections can be effectively used for routine DNA testing.

Molecular ontogeny of donor-derived follicular lymphomas occurring after hematopoietic cell transplantation.

UNLABELLED: The relative timing of genetic alterations that contribute to follicular lymphoma remains unknown. We analyzed a donor-recipient pair who both developed grade 2/3A follicular lymphoma 7 years after allogeneic transplantation and donor lymphocyte infusions. Both patients harbored identical BCL2/IGH rearrangements also present in 1 in 2,000 cells in the donor lymphocyte infusion, and the same V(D)J rearrangement, which underwent somatic hypermutation both before and after clonal divergence. Exome sequencing of both follicular lymphomas identified 15 shared mutations, of which 14 (including alterations in EP300 and KLHL6) were recovered from the donor lymphocyte infusion by ultra-deep sequencing (average read coverage, 361,723), indicating acquisition at least 7 years before clinical presentation. Six additional mutations were present in only one follicular lymphoma and not the donor lymphocyte infusion, including an ARID1A premature stop, indicating later acquisition during clonal divergence. Thus, ultrasensitive sequencing can map clonal evolution within rare subpopulations during human lymphomagenesis in vivo. SIGNIFICANCE: For the first time, we define the molecular ontogeny of follicular lymphoma during clonal evolution in vivo. By using ultrasensitive mutation detection, we mapped the time-course of somatic alterations after passage of a malignant ancestor by hematopoietic cell transplantation.

Dosing clopidogrel based on CYP2C19 genotype and the effect on platelet reactivity in patients with stable cardiovascular disease.

CONTEXT: Variants in the CYP2C19 gene influence the pharmacologic and clinical response to the standard 75-mg daily maintenance dose of the antiplatelet drug clopidogrel. OBJECTIVE: To test whether higher doses (up to 300 mg daily) improve the response to clopidogrel in the setting of loss-of-function CYP2C19 genotypes. DESIGN, SETTING, AND PATIENTS: ELEVATE-TIMI 56 was a multicenter, randomized, double-blind trial that enrolled and genotyped 333 patients with cardiovascular disease across 32 sites from October 2010 until September 2011. INTERVENTIONS: Maintenance doses of clopidogrel for 4 treatment periods, each lasting approximately 14 days, based on genotype. In total, 247 noncarriers of a CYP2C19*2 loss-of-function allele were to receive 75 and 150 mg daily of clopidogrel (2 periods each), whereas 86 carriers (80 heterozygotes, 6 homozygotes) were to receive 75, 150, 225, and 300 mg daily. MAIN OUTCOME MEASURES: Platelet function test results (vasodilator-stimulated phosphoprotein [VASP] phosphorylation and VerifyNow P2Y(12) assays) and adverse events. RESULTS: With 75 mg daily, CYP2C19*2 heterozygotes had significantly higher on-treatment platelet reactivity than did noncarriers (VASP platelet reactivity index [PRI]: mean, 70.0%; 95% CI, 66.0%-74.0%, vs 57.5%; 95% CI, 55.1%-59.9%, and VerifyNow P2Y(12) reaction units [PRU]: mean, 225.6; 95% CI, 207.7-243.4, vs 163.6; 95% CI, 154.4-173.9; P < .001 for both comparisons). Among CYP2C19*2 heterozygotes, doses up to 300 mg daily significantly reduced platelet reactivity, with VASP PRI decreasing to 48.9% (95% CI, 44.6%-53.2%) and PRU to 127.5 (95% CI, 109.9-145.2) (P < .001 for trend across doses for both). Whereas 52% of CYP2C19*2 heterozygotes were nonresponders (≥230 PRU) with 75 mg of clopidogrel, only 10% were nonresponders with 225 or 300 mg (P < .001 for both). Clopidogrel, 225 mg daily, reduced platelet reactivity in CYP2C19*2 heterozygotes to levels achieved with standard clopidogrel, 75 mg, in noncarriers (mean ratios of platelet reactivity, VASP PRI, 0.92; 90% CI, 0.85-0.99, and PRU, 0.94; 90% CI, 0.84-1.04). In CYP2C19*2 homozygotes, even with 300 mg daily of clopidogrel, mean VASP PRI was 68.3% (95% CI, 44.9%-91.6%) and mean PRU, 287.0 (95% CI, 170.2-403.8). CONCLUSION: Among patients with stable cardiovascular disease, tripling the maintenance dose of clopidogrel to 225 mg daily in CYP2C19*2 heterozygotes achieved levels of platelet reactivity similar to that seen with the standard 75-mg dose in noncarriers; in contrast, for CYP2C19*2 homozygotes, doses as high as 300 mg daily did not result in comparable degrees of platelet inhibition. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01235351.

Detection of KIAA1549-BRAF fusion transcripts in formalin-fixed paraffin-embedded pediatric low-grade gliomas.

Alterations of BRAF are the most common known genetic aberrations in pediatric gliomas. They frequently are found in pilocytic astrocytomas, where genomic duplications involving BRAF and the poorly characterized gene KIAA1549 create fusion proteins with constitutive B-Raf kinase activity. BRAF V600E point mutations are less common and generally occur in nonpilocytic tumors. The development of BRAF inhibitors as drugs has created an urgent need for robust clinical assays to identify activating lesions in BRAF. KIAA1549-BRAF fusion transcripts have been detected in frozen tissue, however, methods for FFPE tissue have not been reported. We developed a panel of FFPE-compatible quantitative RT-PCR assays for the most common KIAA1549-BRAF fusion transcripts. Application of these assays to a collection of 51 low-grade pediatric gliomas showed 97% sensitivity and 91% specificity compared with fluorescence in situ hybridization or array comparative genomic hybridization. In parallel, we assayed samples for the presence of the BRAF V600E mutation by PCR pyrosequencing. The data further support previous observations that these two alterations of the BRAF, KIAA1549 fusions and V600E point mutations, are associated primarily with pilocytic astrocytomas and nonpilocytic gliomas, respectively. These results show that fusion transcripts and mutations can be detected reliably in standard FFPE specimens and may be useful for incorporation into future studies of pediatric gliomas in basic science or clinical trials.

Translocation t(1;9) is a recurrent cytogenetic abnormality associated with progression of essential thrombocythemia patients displaying the JAK2 V617F mutation.

A cohort of 338 patients diagnosed with myeloproliferative neoplasms was investigated by conventional cytogenetics and evaluated for the presence of the JAK2 V617F mutation. A t(1;9)(p10;q10) in addition to two extra der(1;9)(q10;p10) chromosomes was observed in two patients of essential thrombocythemia that transformed to acute myelogenous leukemia or to myelofibrosis. These findings suggest that the presence of extra derivative chromosomes der(1q;9p) in combination with the JAK2 V617F mutation may play a role in the progression of myeloproliferative neoplasms and supports the use of cytogenetics in the follow-up of the disease.

Molecular analysis of gene rearrangements and mutations in acute leukemias and myeloproliferative neoplasms.

A large subset of acute leukemias and other myeloproliferative neoplasms contain specific genetic alterations, many of which are associated with unique clinical and pathologic features. These alterations include chromosomal translocations leading to oncogenic fusion genes, as well as mutations leading to aberrant activation of a variety of proteins critical to hematopoietic progenitor cell proliferation and differentiation. Molecular analysis is central to diagnosis and clinical management of leukemias, permitting genetic confirmation of a clinical and histologic impression, providing prognostic and predictive information, and facilitating detection of minimal residual disease. This unit will outline approaches to the molecular diagnosis of the most frequent and clinically relevant genetic alterations in acute leukemias and myeloproliferative neoplasms.

Temozolomide treatment for aggressive pituitary tumors: correlation of clinical outcome with O(6)-methylguanine methyltransferase (MGMT) promoter methylation and expression.

CONTEXT: The typically indolent behavior of pituitary tumors is juxtaposed with high rates of tumor cell invasion into adjacent dural structures, and occasional aggressive behavior. Although clinically significant invasion and malignant transformation remain uncommon, there are limited treatment options available for the management of these aggressive tumors. Recently, case reports have described efficacy of temozolomide for the treatment of aggressive pituitary tumors. DESIGN: Seven patients with aggressive pituitary tumors have been treated with temozolomide. We compared O(6)-methylguanine methyltransferase (MGMT) promoter methylation and MGMT expression in 14 surgical specimens from these seven patients and correlated these molecular features with the clinical response to temozolomide. RESULTS: Significant tumor regression was seen in two patients (29%), a 20% reduction in tumor volume with subsequent stable tumor size was noted in one patient, arrest of tumor growth occurred in three patients, and progressive metastatic disease developed during treatment in one patient. The DNA promoter site for MGMT was unmethylated in all 14 adequate specimens, and variable MGMT expression was seen in all 14 cases. There was no correlation between MGMT expression and clinical outcomes. CONCLUSIONS: We conclude that medical therapy with temozolomide can be helpful in the management of life-threatening pituitary tumors that have failed to respond to conventional treatments. The optimal duration of treatment in patients with stabilization or reduction of tumor size has not been established, and long-term follow up studies are needed.