Faculty Bibliography

OBJECTIVES/OBJECTIVE:The interaction between the immune system and tumor cells is an important feature for the prognosis and treatment of cancer. Multiplex immunohistochemistry (mIHC) and multiplex immunofluorescence (mIF) analyses are emerging technologies that can be used to help quantify immune cell subsets, their functional state, and their spatial arrangement within the tumor microenvironment. METHODS:The Society for Immunotherapy of Cancer (SITC) convened a task force of pathologists and laboratory leaders from academic centers as well as experts from pharmaceutical and diagnostic companies to develop best practice guidelines for the optimization and validation of mIHC/mIF assays across platforms. RESULTS:Representative outputs and the advantages and disadvantages of mIHC/mIF approaches, such as multiplexed chromogenic IHC, multiplexed immunohistochemical consecutive staining on single slide, mIF (including multispectral approaches), tissue-based mass spectrometry, and digital spatial profiling are discussed. CONCLUSIONS:mIHC/mIF technologies are becoming standard tools for biomarker studies and are likely to enter routine clinical practice in the near future. Careful assay optimization and validation will help ensure outputs are robust and comparable across laboratories as well as potentially across mIHC/mIF platforms. Quantitative image analysis of mIHC/mIF output and data management considerations will be addressed in a complementary manuscript from this task force.

The premise of this book is the importance of the tumor microenvironment (TME). Until recently, most research on and clinical attention to cancer biology, diagnosis, and prognosis were focused on the malignant (or premalignant) cellular compartment that could be readily appreciated using standard morphology-based imaging.

PURPOSE: In patients with chronic myelogenous leukemia (CML), point mutations in the BCR-ABL1 kinase domain are the most common cause of treatment failure with a tyrosine kinase inhibitor (TKI). It is not clear whether the splice variant BCR-ABL135INS is also associated with treatment failure. PATIENTS AND METHODS: We reviewed all CML patients who had BCR-ABL1 kinase mutation analysis performed between August 1, 2007, and January 15, 2014. Patients who had BCR-ABL135INS detected had their medical records reviewed to determine response to TKI therapy. RESULTS: Two hundred and eighty four patients had kinase mutation testing performed; of these, 64 patients (23%) had BCR-ABL135INS detected. Forty-five patients were in chronic phase (70%), 10 were in accelerated phase (16%), 6 were in blastic phase (9%), and 3 were in other settings (5%). Of the 34 chronic phase patients who began therapy with imatinib, 23 patients (68%) failed therapy: 8 patients (24%) had primary refractory disease, 11 patients (32%) progressed, and 4 patients (12%) had disease progression after dose interruption. In contrast to the patients with disease progression or lack of response, none of 23 patients who were responding to imatinib had BCR-ABL135INS detected. DNA sequencing of commonly mutated spliceosomal genes SF3B1, U2AF1, SRSF2, ZRSR2, SFA31, PRPF408, U2A565, and SF1 did not reveal mutations in seven BCR-ABL135INS -positive patients tested. CONCLUSIONS: The splice variant BCR-ABL135INS is frequently found in patients who are resistant to imatinib. Mutations in the commonly mutated spliceosomal proteins do not contribute to this association.

Amplicon-based methods for targeted resequencing of cancer genes have gained traction in the clinic as a strategy for molecular diagnostic testing. An 847-amplicon panel was designed with the RainDance DeepSeq system, covering most exons of 28 genes relevant to acute myeloid leukemia and myeloproliferative neoplasms. We developed a paired-sample analysis pipeline for variant calling and sought to assess its sensitivity and specificity relative to a set of samples with previously identified mutations. Thirty samples with known mutations in JAK2, NPM1, DNMT3A, MPL, IDH1, IDH2, CEBPA, and FLT3, were profiled and sequenced to high depth. Variant calling using an unmatched Hapmap DNA control removed a substantial number of artifactual calls regardless of algorithm used or variant class. The removed calls were nonunique, had lower variant frequencies, and tended to recur in multiple unrelated samples. Analysis of sample replicates revealed that reproducible calls had distinctly higher variant allele depths and frequencies compared to nonreproducible calls. On the basis of these differences, filters on variant frequency were chosen to select for reproducible calls. The analysis pipeline successfully retrieved the associated known variant in all tested samples and uncovered additional mutations in some samples corresponding to well-characterized hotspot mutations in acute myeloid leukemia. We have developed a paired-sample analysis pipeline capable of robust identification of mutations from microdroplet-PCR sequencing data with high sensitivity and specificity.

IMPORTANCE: Uveal melanoma is characterized by mutations in GNAQ and GNA11, resulting in mitogen-activated protein kinase pathway activation. OBJECTIVE: To assess the efficacy of selumetinib, a selective, non-adenosine triphosphate competitive inhibitor of MEK1 and MEK2, in uveal melanoma. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label, phase 2 clinical trial comparing selumetinib vs chemotherapy conducted from August 2010 through December 2013 among 120 patients with metastatic uveal melanoma at 15 academic oncology centers in the United States and Canada. INTERVENTIONS: One hundred one patients were randomized in a 1:1 ratio to receive selumetinib, 75 mg orally twice daily on a continual basis (n = 50), or chemotherapy (temozolomide, 150 mg/m2 orally daily for 5 of every 28 days, or dacarbazine, 1000 mg/m2 intravenously every 21 days [investigator choice]; n = 51) until disease progression, death, intolerable adverse effects, or withdrawal of consent. After primary outcome analysis, 19 patients were registered and 18 treated with selumetinib without randomization to complete the planned 120-patient enrollment. Patients in the chemotherapy group could receive selumetinib at the time of radiographic progression. MAIN OUTCOMES AND MEASURES: Progression-free survival, the primary end point, was assessed as of April 22, 2013. Additional end points, including overall survival, response rate, and safety/toxicity, were assessed as of December 31, 2013. RESULTS: Median progression-free survival among patients randomized to chemotherapy was 7 weeks (95% CI, 4.3-8.4 weeks; median treatment duration, 8 weeks; interquartile range [IQR], 4.3-16 weeks) and among those randomized to selumetinib was 15.9 weeks (95% CI, 8.4-21.1 weeks; median treatment duration, 16.1 weeks; IQR, 8.1-25.3 weeks) (hazard ratio, 0.46; 95% CI, 0.30-0.71; P < .001). Median overall survival time was 9.1 months (95% CI, 6.1-11.1 months) with chemotherapy and 11.8 months (95% CI, 9.8-15.7 months) with selumetinib (hazard ratio, 0.66; 95% CI, 0.41-1.06; P = .09). No objective responses were observed with chemotherapy. Forty-nine percent of patients treated with selumetinib achieved tumor regression, with 14% achieving an objective radiographic response to therapy. Treatment-related adverse events were observed in 97% of patients treated with selumetinib, with 37% requiring at least 1 dose reduction. CONCLUSIONS AND RELEVANCE: In this hypothesis-generating study of patients with advanced uveal melanoma, selumetinib compared with chemotherapy resulted in a modestly improved progression-free survival and response rate; however, no improvement in overall survival was observed. Improvement in clinical outcomes was accompanied by a high rate of adverse events. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01143402.

The role of the proliferation index (PI) as an outcome predictor in follicular lymphoma (FL) isn't clear. We have previously demonstrated that quantitative image analysis (QIA) is a robust tool for PI determination and the present study aimed to determine the significance of the PI for outcome in low-grade FL. One hundred and twenty-nine patients with grade 1-2 FL were retrospectively analysed. Slides were scanned digitally and follicle/tumour-involved areas were annotated. The intrafollicular PI was estimated by analysing a median of 10 follicles per case. Patients were divided into two groups: PI < 30%, PI >/= 30% and clinical outcome was analysed. Among the 129 patients analysed, intrafollicular PI ranged from 0.6 to 63.2% with a median of 23.3%. Overall survival was not influenced by PI group. Among those patients initially observed, intrafollicular PI < 30% was associated with longer time to first therapy compared to patients with a PI >/= 30%. In the group of patients that were treated at diagnosis, PI was not predictive of time to treatment failure (TTTF). Intrafollicular PI is an important predicator of TTFT for patients who are candidates for observation. Further confirmation in an independent cohort of patients is necessary to determine the clinical validity of the results.

During recent years, it has become increasingly evident that donor leukemia following allogeneic transplant may be more common then realized in the past. We identified five cases of potential donor leukemia cases during past five years. The precise mechanism of the origin of such leukemias, however, remains poorly defined. In this short communication, we report a well documented case of donor-derived de novo acute myeloid leukemia (AML) that developed fourteen years after allogeneic stem cell transplantation for treatment induced AML for his primary malignancy Immunoblastic lymphoma. This case allows us to postulate a possible mechanism of the origin of donor leukemia. The de novo AML clone contained a distinct cytogenetic abnormality, trisomy 11, which was simultaneously detected in preserved peripheral blood obtained at the time of transplantation as well as in the current bone marrow from an otherwise clinically and phenotypically normal donor. The findings from this unique case, provides insight into the process of leukemogenesis, and suggests that the sequence of events leading to leukemogenesis in this patient involved the senescence/apoptosis of normal donor hematopoietic cells due to telomere shortening resulting in the selective proliferation and transformation of this clone with MLL (mixed-lineage leukemia) gene amplification.