Jane Starczynski

Mcl-1 expression has in vitro and in vivo significance in chronic lymphocytic leukemia and is associated with other poor prognostic markers

Bcl-2 family proteins play a critical role in the regulation of apoptosis in chronic lymphocytic leukemia (CLL). However, their association with established prognostic markers is unknown. In this study, we analyzed the expression of Bcl-2, Bax, and Mcl-1 in 185 CLL patients and evaluated their relationship with other prognostic markers, in vitro sensitivity to fludarabine, and clinical outcome. Mcl-1 expression was significantly correlated with stage of disease (P < .001), lymphocyte doubling time (P = .01), V(H) gene mutation status (P < .001), CD38 expression (P < .001), and ZAP-70 expression (P = .003). In addition, Mcl-1 and Mcl-1/Bax ratios showed strong correlations with in vitro resistance to fludarabine (P = .005 and P < .001, respectively). Furthermore, elevated Mcl-1 expression and Mcl-1/Bax ratios were predictive of time to first treatment in the whole cohort (P < .001 and P < .001, respectively) and in stage A patients only (P = .002 and P = .001, respectively). Taken together, our data show that Mcl-1 is a key controller of in vitro drug resistance and is an important regulator of disease progression and outcome in CLL. It therefore represents a promising therapeutic target in this incurable condition. The close correlation between Mcl-1 expression and V(H) gene mutation status, CD38 expression, and ZAP-70 expression offers a biologic explanation for their association with adverse prognosis.

An international study to increase concordance in Ki67 scoring

Although an important biomarker in breast cancer, Ki67 lacks scoring standardization, which has limited its clinical use. Our previous study found variability when laboratories used their own scoring methods on centrally stained tissue microarray slides. In this current study, 16 laboratories from eight countries calibrated to a specific Ki67 scoring method and then scored 50 centrally MIB-1 stained tissue microarray cases. Simple instructions prescribed scoring pattern and staining thresholds for determination of the percentage of stained tumor cells. To calibrate, laboratories scored 18 ‘training’ and ‘test’ web-based images. Software tracked object selection and scoring. Success for the calibration was prespecified as Root Mean Square Error of scores compared with reference <0.6 and Maximum Absolute Deviation from reference <1.0 (log2-transformed data). Prespecified success criteria for tissue microarray scoring required intraclass correlation significantly >0.70 but aiming for observed intraclass correlation ≥0.90. Laboratory performance showed non-significant but promising trends of improvement through the calibration exercise (mean Root Mean Square Error decreased from 0.6 to 0.4, Maximum Absolute Deviation from 1.6 to 0.9; paired t-test: P=0.07 for Root Mean Square Error, 0.06 for Maximum Absolute Deviation). For tissue microarray scoring, the intraclass correlation estimate was 0.94 (95% credible interval: 0.90–0.97), markedly and significantly >0.70, the prespecified minimum target for success. Some discrepancies persisted, including around clinically relevant cutoffs. After calibrating to a common scoring method via a web-based tool, laboratories can achieve high inter-laboratory reproducibility in Ki67 scoring on centrally stained tissue microarray slides. Although these data are potentially encouraging, suggesting that it may be possible to standardize scoring of Ki67 among pathology laboratories, clinically important discrepancies persist. Before this biomarker could be recommended for clinical use, future research will need to extend this approach to biopsies and whole sections, account for staining variability, and link to outcomes.

Updated UK Recommendations for HER2 assessment in breast cancer.

Human epidermal growth factor receptor 2 (HER2) overexpression is present in approximately 15% of early invasive breast cancers, and is an important predictive and prognostic marker. The substantial benefits achieved with anti-HER2 targeted therapies in patients with HER2-positive breast cancer have emphasised the need for accurate assessment of HER2 status. Current data indicate that HER2 test accuracy improved following previous publication of guidelines and the implementation of an external quality assessment scheme with a decline in false-positive and false-negative rates. This paper provides an update of the guidelines for HER2 testing in the UK. The aim is to further improve the analytical validity and clinical utility of HER2 testing by providing guidelines of test performance parameters, and recommendations on the postanalytical interpretation of test results. HER2 status should be determined in all newly diagnosed and recurrent breast cancers. Testing involves immunohistochemistry with >10% complete strong membrane staining defining a positive status. In situ hybridisation, either fluorescent or bright field chromogenic, is used either upfront or in immunohistochemistry borderline cases to detect the presence of HER2 gene amplification. Situations where repeat HER2 testing is advised are outlined and the impact of genetic heterogeneity is discussed. Strict quality control and external quality assurance of validated assays are essential. Testing laboratories should perform ongoing competency assessment and proficiency tests and ensure the reliability and accuracy of the assay. Pathologists, oncologists and surgeons involved in test interpretation and clinical use should adhere to published guidelines and maintain accurate performance and consistent interpretation of test results.

Common polymorphism G(-248)A in the promoter region of the bax gene results in significantly shorter survival in patients with chronic lymphocytic Leukemia once treatment is initiated.

PURPOSE Chronic lymphocytic leukemia (CLL) is characterized by the development of drug resistance. The underlying biologic and genetic reasons for this resistance are complex, but the bcl-2 gene family seems to play a critical role. This retrospective study assessed the clinical impact of a common single nucleotide polymorphism of the pro-apoptotic bax gene in patients with chronic lymphocytic leukemia. PATIENTS AND METHODS The frequency of the novel polymorphism, G(-248)A, in the promoter region of the bax gene and bax protein expression was assessed in 203 CLL patients. The results were correlated with clinical outcome. RESULTS The polymorphism was found in 23% of the CLL cohort and 15% of normal controls with no significant difference in allele frequency between the two groups (P = .15). It was associated with lower Bax protein expression and a shorter overall survival, especially in the treated patient group (P = .03). Furthermore, the adverse impact of the polymorphism was accentuated when comparing survival from the date of first treatment rather than diagnosis (P = .012). No significant difference in age at diagnosis, stage of disease at presentation, lymphocyte doubling time, time to first treatment, or progression-free survival were observed. CONCLUSION The presence of this single nucleotide polymorphism in CLL critically influences the response to treatment and overall survival. Given the relatively high prevalence of this polymorphism in the normal population, further prospective studies in CLL and other human malignancies are indicated.

The effect of immunoglobulin VH gene mutation status and other prognostic factors on the incidence of major infections in patients with chronic lymphocytic leukemia

Infections are a major factor in the clinical course of chronic lymphocytic leukemia (CLL) and account for 30% to 50% of all deaths. The pathogenesis of infections in CLL is related to hypo‐γ‐globulinemia, T‐cell immune dysfunction, and the immunosuppressive effect of treatment.

HER2 testing in the UK: recommendations for breast and gastric in-situ hybridisation methods

These guidelines supplement existing guidelines on HER2 testing by immunohistochemistry and in-situ hybridisation(ISH) methods in the UK. They provide a specific focus on aspects of guidance relevant to HER2 ISH testing methods, both fluorescent and chromogenic. They are formulated to give advice on methodology, interpretation and quality control for ISH-based testing of HER2 status in common tumour types, including both breast and gastric tumours. The aim is to ensure that all ISH-based testing is accurate, reliable and timely.

Highly purified CD38+ and CD38- sub-clones derived from the same chronic lymphocytic leukemia patient have distinct gene expression signatures despite their monoclonal origin.

CD38 expression is an important prognostic marker in chronic lymphocytic leukemia (CLL) with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38+ and CD38− chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38+ and CD38− CLL cells derived from the same patient were shown to be monoclonal by VH gene sequencing but despite this, CD38+ CLL cells possessed a distinct gene expression profile when compared with their CD38− sub-clones. Importantly, CD38+ CLL cells relatively over expressed vascular endothelial growth factor (VEGF) and appeared to preferentially utilize an internal autocrine VEGF survival loop. Elevated VEGF expression was associated with increased expression of the anti-apoptotic protein Mcl-1. Inhibition of VEGF receptor signaling also resulted in a reduction in cell viability. In contrast, exogenous VEGF caused a significant increase in CD38− CLL cell viability and a marked induction of Mcl-1; both effects were less obvious in CD38+ CLL cells. Taken together, our data provide a biological rationale for the poor prognosis of CD38+ CLL and indicate that both VEGF and Mcl-1 may prove to be useful therapeutic targets.

The P2X7 receptor gene polymorphism 1513 A→C has no effect on clinical prognostic markers, in vitro sensitivity to fludarabine, Bcl‐2 family protein expression or survival in B‐cell chronic lymphocytic leukaemia

Summary. A cohort of 121 patients with B‐cell chronic lymphocytic leukaemia (B‐CLL) was investigated for a single nucleotide polymorphism in the P2X7 receptor gene (1513 A→C), and the findings were correlated with clinical prognostic markers, in vitro sensitivity to fludarabine, expression of Bcl‐2 family proteins and overall survival. The frequency of the polymorphism in B‐CLL samples was not significantly different from that found in normal healthy controls (P = 0·27; Fishers exact test). Furthermore, when the B‐CLL patients were analysed according to P2X7 genotype (1513 A/A versus 1513 A/C), there was no significant difference in age at diagnosis, stage at diagnosis, lymphocyte doubling time, time to first treatment, progression‐free survival and overall survival, and neither was there any evidence of bias in terms of VH gene mutational status, CD38 expression, in vitro sensitivity to fludarabine or expression of Bcl‐2, Bax or Mcl‐1 between the two groups. These results indicate that the 1513 A→C polymorphism of the P2X7 gene is unlikely to play a significant role in the pathogenesis or disease progression of B‐CLL.

The updated ASCO/CAP guideline recommendations for HER2 testing in the management of invasive breast cancer: a critical review of their implications for routine practice

The American Society of Clinical Oncology and the College of American Pathologists have issued joint updated comprehensive guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer. The update not only provides guidelines for the test performance parameters, with the aim of improving test accuracy, reproducibility, and precision, but also provides comprehensive recommendations on the post‐analytical interpretation of the results, and requires improved communication among healthcare providers. The updated guidelines are targeted at testing laboratories, pathologists, oncologists, surgeons, and, indirectly, other healthcare providers. Although the guidelines contribute to the improved analytical validity and clinical utility of laboratory assays required for successful molecularly targeted therapy in the era of personalized medicine, the implications of such recommendations have to be acknowledged. Certain recommendations, particularly those related to repeating the test and pathological concordance, have lower levels of supportive evidence than existing key recommendations, and the associated workload implications will be challenging to support in most healthcare systems. In this commentary, we critically address the key updated recommendations and their impact on service provision and patient care.

Chromogenic In Situ Hybridization A Multicenter Study Comparing Silver In Situ Hybridization With FISH

Our purposes were to perform a robust assessment of a new HER2 chromogenic in situ hybridization test and report on concordance of silver in situ hybridization (SISH) data with fluorescence in situ hybridization (FISH) data and on intraobserver and interlaboratory scoring consistency. HER2 results were scored from 45 breast cancers in 7 laboratories using the Ventana (Tucson, AZ) INFORM HER-2 SISH assay and in 1 central laboratory using a standard FISH assay. Overall, 94.8% of cases were successfully analyzed by SISH across the 6 participating laboratories that reported data. Concordance for diagnosis of HER2 amplification by SISH compared with FISH was high (96.0% overall). Intraobserver variability (8.0%) and intersite variability (12.66%) of absolute HER2/chromosome 17 ratios appear to be tightly controlled across all 6 participating laboratories. The Ventana INFORM HER-2 SISH assay is robust and reproducible, shows good concordance with a standard FISH assay, and complies with requirements in national guidelines for performance of diagnostic tests.