Janina A. Longtine

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.

Cutaneous b-cell lymphomas of follicular and marginal zone types: use of Bcl-6, CD10, Bcl-2, and CD21 in differential diagnosis and classification.

Cutaneous follicular lymphomas (FLs) and cutaneous B-cell lymphomas of extranodal marginal zone (MZL)/mucosal-associated lymphoid tissue (MALT) type may have morphologic overlap, despite the fact that they are thought to be of distinct derivation (germinal center vs. postgerminal center). The problem is compounded by the reported absence of bcl-2 expression by many cutaneous FLs, leading to speculation that cutaneous FL may be unrelated to nodal FL. The authors analyzed the expression of the germinal center-associated antigens bcl-6 and CD10 and of bcl-2 in 18 cutaneous B-cell lymphomas (10 FLs and eight MZLs), in relationship to CD21+ follicular structures, to clarify the relationship of nodal to cutaneous FLs and to explore the value of these antigens in differential diagnosis. The authors studied 10 cutaneous FLs (seven primary and three secondary) and eight MZLs (six primary and two secondary). The FLs (found in six men and four women age 45–75 years) involved the trunk (n = 3) and scalp, face and neck (n = 7). The MZLs (found in five women and three men age 34–81 years) involved the trunk (n = 4), face and neck (n = 2), and arm (n = 2). Immunostaining for CD21, bcl-6, CD10, and bcl-2 allowed the delineation of compartments within the tumors and yielded distinct patterns of staining in FL and MZL. In both follicular and interfollicular/diffuse areas of FL the neoplastic cells were bcl-6+ (10 of 10), often CD10+ (seven of 10, four of seven primary), and bcl-2+ (nine of 10, six of seven primary). Only three of seven cases (one of five primary) had bcl-2 rearrangement detectable by polymerase chain reaction. In the MZLs, the neoplastic B-cells were bcl-6−, CD10−, and bcl-2+ (eight of eight). Three patterns of CD21+ follicles were identified in MZL: reactive germinal centers, uniformly bcl-6+, CD10+, and bcl-2− (five of eight MZLs); colonized follicles, both bcl-6−, bcl-2+, and L26+ cells, and bcl-6+ and bcl-2− cells (five of eight MZLs); and expanded/colonized follicular dendritic cell meshworks, bcl-6− and bcl-2+ B cells with rare residual bcl-6+ and bcl-2− cells (four of eight MZLs). The authors conclude that cutaneous FLs express bcl-6 uniformly, usually express CD10 and bcl-2, and have a follicular pattern similar to nodal FL and consistent with a germinal center origin. The immunophenotype of cutaneous FL is distinct from that of cutaneous MZL, which is negative for bcl-6 and CD10. Colonized follicles in MZL, identified by CD21+ follicular dendritic cell meshworks, contained numerous bcl-6− and bcl-2+ B cells, and were readily distinguished from neoplastic follicles in FL. Conversely, CD21− interfollicular and diffuse areas in FLs contained bcl-6+ and CD10+ cells, which were not seen in diffuse areas of MZLs. Thus, the combination of bcl-2, bcl-6, and CD21 staining is useful for the distinction of cutaneous MZL from cutaneous FL.

Temozolomide Treatment for Aggressive Pituitary Tumors: Correlation of Clinical Outcome with O6-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.

Telepathology diagnosis by means of digital still images: An international validation study

Telepathology affords the means to provide pathological diagnosis and consultation to remote sites. However, before telepathology can become an acceptable medical tool, it will be vital to determine the diagnostic accuracy of this technology. We report the results of a single-blind study of the accuracy of diagnosis performed using computerized still images obtained from a telepathology workstation used in a French telepathology network. Four pathologists, each working alone, reviewed a total of 200 cases of routine surgical pathology (50 cases each), and performed diagnosis based on both computer CD-ROM still images (CD) and conventional glass slides (GS). Concordance between GS and CD diagnosis, as well as accuracy, were determined. Other factors related to performance were also measured, including diagnostic certainty, reasons for uncertainty, and causes of diagnostic error. Overall, there was good agreement between CS and CD diagnosis. There was 87.5% concordance between CS and CD diagnosis, and comparison to consensus (correct) diagnosis showed accuracy of 95.5% and 88.5% for GS and CD diagnosis, respectively. Marked variability in accuracy of CD diagnosis was observed among the four pathologists, and issues related to image selection and/or quality appeared responsible for 60% of the diagnostic errors. The lack of sufficient images and clinical information were frequently cited as reasons for diagnostic uncertainty, as well as feelings of insufficient expertise. It is likely that the opportunity for interaction with the referring pathologist and the use of subspecialty consultants would likely improve the performance of telepathology.

Ki‐1–positive large cell lymphomas, a heterogenous group of neoplasms. Morphologic, immunophenotypic, genotypic, and clinical features of 24 cases

Clinical and pathologic features of 24 patients with large cell lymphomas that expressed the activation antigen Ki‐1 are described. Phenotypic and/or genotypic studies characterized these neoplasms as T‐cell (16 cases), B‐cell (six cases), or null cell (two cases) type. Males predominantly were affected. Age of patients ranged from 19 to 73 years, with a bimodal distribution, with peaks in the third and seventh decades. Lymphadenopathy was present in nearly all patients. Extranodal involvement, including skin, soft tissue, bone, central nervous system, lung, or small intestine was observed in a total of 54% of the patients, either at presentation or during the course of disease. “Prototypic” features of large cell anaplastic lymphomas were observed for eight T‐cell lymphomas, with morphologic heterogeneity noted for the remainder. Eight patients, all with T‐cell neoplasms (only one with prototypic morphology), have died of lymphoma (median survival, 5 months). An antecedent history of a lymphoproliferative disorder (mycosis fungoides, B‐cell lymphoma, immunoblastic lymphadenopathy) was apparent in seven patients. An 8‐year history of Crohns disease occurred in one patient with a T‐cell lymphoma involving small intestine. Phenotypically, loss of one or more markers was typically noted for T‐cell neoplasms. Leukocyte common antigen was detected in all cases, although partial loss of immunoreactivity was noticed in some cases. Nearly all cases evaluated for Ia antigen or alpha‐1‐antichymotrysin were reactive. Eleven of 16 T‐cell, two of six B‐cell, and two null cell lymphomas expressed epithelial membrane antigen. Ki‐1–positive large cell lymphomas are characterized by clinical, morphologic, and immunophenotypic heterogeneity.

Peripheral T-cell lymphoma with follicular involvement and a CD4+/bcl-6+ phenotype.

A truly follicular pattern is thought to be restricted to B-cell lymphomas. We observed a prominent follicular growth pattern in three cases of nodal peripheral T-cell lymphomas, of which two were initially diagnosed as follicular lymphomas. All three patients were male, ranged in age from 50 to 70 years, and had generalized lymphadenopathy at the time of diagnosis. The follicles were sharply demarcated in two cases and large and vague in one case; in all cases, they contained abundant follicular dendritic cells. Neoplastic cells were small to medium, with irregular cleaved or round nuclei and clear cytoplasm, which was abundant in one case. Lymphoma cells in all cases were CD4+ CD8− CD57− bcl-6, with CD10 coexpression in 2 cases. Clonal rearrangement of the gamma chain of the T-cell receptor gene was demonstrated in each case. These cases expand the differential diagnosis of lymphomas with a follicular growth pattern and suggest that neoplastic T cells may have the capacity to induce or home to follicular structures.

Epidermal Growth Factor Receptor Mutation Testing in the Care of Lung Cancer Patients

As the literature about epidermal growth factor receptor (EGFR) mutations grows and screening for mutations becomes increasingly integrated into clinical care, it is important to examine how best to do somatic mutational analyses and how best to use the test results in clinical decision making. We began offering mutation screening by comprehensive direct sequence analysis of exons 18 to 24 of the tyrosine kinase domain of EGFR in August 2004 as part of clinical cancer care and protocol therapy at our institutions. All identified potential mutations are confirmed with three to five independent PCRs of the original genomic DNA sample and, if not previously noted in the literature, are compared with the patients germ-line DNA to ensure the finding is somatic. We formally analyzed the first 100 patients to undergo EGFR sequence analysis and found that testing was feasible and significantly affected the treatment of patients with non–small cell lung cancer (NSCLC). Patients harboring EGFR mutations were significantly more likely to receive recommendations for therapy with EGFR tyrosine kinase inhibitors (i.e., gefitinib or erlotinib) than patients without mutations. However, negative EGFR test results did not prevent physicians from administering these agents to selected patients. Ideally, a standardized technique for mutation testing could be developed, with demonstrated reproducibility and validity. Clinical trials incorporating molecular diagnostics are ongoing to assess the efficacy of EGFR tyrosine kinase inhibitors as first-line therapy for metastatic NSCLC and as adjuvant therapy for early-stage resected NSCLC. It is likely that mutation testing and other molecular analyses will be most useful in these two clinical situations.

Extended Follow-up of Patients Treated with Imatinib Mesylate (Gleevec) for Chronic Myelogenous Leukemia Relapse after Allogeneic Transplantation: Durable Cytogenetic Remission and Conversion to Complete Donor Chimerism without Graft-versus-Host Disease

Purpose: Over the last several years, donor lymphocyte infusions have become the standard approach for patients with chronic myelogenous leukemia (CML) who relapse after allogeneic stem cell transplantation (SCT). Recent reports indicate that imatinib mesylate (Gleevec) can induce remissions in these patients as well. Less is known about the extent and durability of these responses. Experimental Design: We studied 15 patients treated with imatinib for recurrent CML after SCT, 10 patients with stable phase CML (SP-CML), 1 with accelerated phase (AP-CML), and 4 with blast phase (BP-CML). The dose of imatinib was 600 mg (n = 10) or 400 mg (n = 5) daily. Patients were followed for hematological, cytogenetic, and molecular response. A susbset of responders was followed for changes in donor-derived hematopoietic chimerism. Results: Of the 10 patients with SP-CML, all achieved a hematological response. Within 3 months, five of these patients had achieved a complete cytogenetic response (CCR). By six months, 9 of 10 patients had achieved CCR. The BCR-ABL transcript could not be detected by reverse transcription-PCR in 7 of these 9 patients. Patients who achieved CCR showed evidence of conversion to complete donor chimerism. No patient developed graft-versus-host disease. With a median follow up of 25 months, all patients are alive and 9 of 10 patients remain in CCR. Only one of the 5 patients with AP/BP-CML achieved a complete cytogenetic response. Conclusions: We find that imatinib is well tolerated in patients with SP-CML who relapse after SCT. Responses were rapid, durable, and associated with conversion to full donor chimerism without graft-versus-host disease. Imantinib was far less effective in patients who relapsed with AP/BP-CML. Imatinib should be evaluated as either an alternative or as an adjunct to donor lymphocyte infusions for patients with SP-CML who relapse after SCT.

CD20+ T-cell lymphoma: clinicopathologic analysis of 9 cases and a review of the literature.

Rare cases of CD20+ T-cell lymphoma (TCL) have been reported, but the clinicopathologic spectrum of this disorder is not known. We identified 9 cases of CD20+ TCL diagnosed at our institution and 26 additional cases through a search of the English language literature. Among current cases, there were 7 men (ages 71 to 81, median 75 y) and 2 women (ages 36 and 37 y). Five patients presented with predominantly nodal disease (localized in 3 and widespread in 2 cases) and 4 patients presented with purely extranodal disease involving the parotid glands, skin, or small intestine. CD20 was uniformly and strongly expressed in 5 cases and dimly expressed or present on a subset of neoplastic cells in 4 cases. The proportion of CD20+ T cells changed over time in 3 cases. Three cases fulfilled diagnostic criteria for clinicopathologically defined subtypes of TCL (2 mycosis fungoides; 1 enteropathy-type TCL), whereas 6 were peripheral TCL unspecified with variable cytomorphology, T-cell immunophenotype, and sites of involvement. In 8 of 9 cases, a clonal T-cell population was identified by molecular genetic analysis. Among 8 cases with clinical follow-up, 5 behaved aggressively with death from disease within 3 years of diagnosis in 4 cases (median survival: 11 mo, range: 1 to 35 mo), and recurrent disease at 10 months in 1 case; 1 patient died of an EBV+ B-cell lymphoma (BCL) 66 months after the original diagnosis; in the remaining 2 cases, patients were alive and undergoing treatment (follow-up: 4 and 18 mo). Historical cases showed similar clinicopathologic variability. CD20+ TCL is rare, and clinically and pathologically heterogeneous. When CD20 expression is present in TCL, it may be dimmer than that of normal B cells, suggesting neoplastic transformation of a normal CD20dim+ T-cell subset. Cases of CD20+ TCL in which the proportion of CD20+ cells changes over time may reflect aberrant expression of CD20, possibly as an activation marker, by neoplastic T cells. CD20+ TCL may cause diagnostic difficulty, particularly in cases that clinically and pathologically mimic BCL. Knowledge of the unusual phenomenon of CD20 expression in TCL, in conjunction with careful morphologic analysis, the use of a panel of antibodies, and molecular genetic studies, is important in avoiding a misdiagnosis of BCL.

Phase II study of temozolomide, thalidomide, and celecoxib for newly diagnosed glioblastoma in adults

We conducted a phase II study of the combination of temozolomide and angiogenesis inhibitors for treating adult patients with newly diagnosed glioblastoma. Patients who had stable disease following standard radiation therapy received temozolomide for 5 days in 28-day cycles, in combination with daily thalidomide and celecoxib. Patients were treated until tumor progression or development of unacceptable toxicity. Four-month progression-free survival (PFS) from study enrollment was the primary end point, and overall survival (OS) was the secondary end point. In addition, we sought to correlate response with O(6)-methylguanine-DNA methyltransferase promoter methylation status and serum levels of angiogenic peptides. Fifty patients with glioblastoma were enrolled (18 women, 32 men). Median age was 54 years (range, 29-78) and median KPS score was 90 (range, 70-100). From study enrollment, median PFS was 5.9 months (95% confidence interval [CI]: 4.2-8.0) and 4-month PFS was 63% (95% CI: 46%-75%). Median OS was 12.6 months (95% CI: 8.5-16.4) and 1-year OS was 47%. Of the 47 patients evaluable for best response, none had a complete response, five (11%) had partial response, four (9%) had minor response, 22 (47%) had stable disease, and 16 (34%) had progressive disease. Analysis of serial serum samples obtained from 47 patients for four angiogenic peptides failed to show a significant correlation with response or survival for three of the peptides; higher vascular endothelial growth factor levels showed a trend toward correlation with decreased OS (p=0.07) and PFS (p=0.09). The addition of celecoxib and thalidomide to adjuvant temozolomide was well tolerated but did not meet the primary end point of improvement of 4-month PFS from study enrollment.