Statistical Literacy Among Academic Pathologists: A Survey Study to Gauge Knowledge of Frequently Used Statistical Tests Among Trainees and Faculty.

CONTEXT: -Statistical literacy can be defined as understanding the statistical tests and terminology needed for the design, analysis, and conclusions of original research or laboratory testing. Little is known about the statistical literacy of clinical or anatomic pathologists. OBJECTIVE: -To determine the statistical methods most commonly used in pathology studies from the literature and to assess familiarity and knowledge level of these statistical tests by pathology residents and practicing pathologists. DESIGN: -The most frequently used statistical methods were determined by a review of 1100 research articles published in 11 pathology journals during 2015. Familiarity with statistical methods was determined by a survey of pathology trainees and practicing pathologists at 9 academic institutions in which pathologists were asked to rate their knowledge of the methods identified by the focused review of the literature. RESULTS: -We identified 18 statistical tests that appear frequently in published pathology studies. On average, pathologists reported a knowledge level between "no knowledge" and "basic knowledge" of most statistical tests. Knowledge of tests was higher for more frequently used tests. Greater statistical knowledge was associated with a focus on clinical pathology versus anatomic pathology, having had a statistics course, having an advanced degree other than an MD degree, and publishing research. Statistical knowledge was not associated with length of pathology practice. CONCLUSIONS: -An audit of pathology literature reveals that knowledge of about 12 statistical tests would be sufficient to provide statistical literacy for pathologists. On average, most pathologists report they can interpret commonly used tests but are unable to perform them. Most pathologists indicated that they would benefit from additional statistical training.

Differential expression and clinical significance of tyrosine-phosphorylated STAT3 in ALK+ and ALK- anaplastic large cell lymphoma.

PURPOSE: Recent data suggest that nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) activates signal transducers and activators of transcription 3 (STAT3) directly, and ALK expression correlates with STAT3 activation in non-Hodgkin's lymphomas. In this study, we evaluated comprehensively STAT3 activation status in anaplastic large cell lymphoma (ALCL) cell lines and pretreatment ALCL tumors. EXPERIMENTAL DESIGN: The study included five ALK(+)ALCL cell lines and 80 systemic ALCL tumors (31 ALK(+), 49 ALK(-)) that were formalin fixed and paraffin embedded. All 80 patients with systemic ALCL were treated with doxorubicin-based chemotherapy. The STAT3 activation status in cell lines was determined using Western blots and an antibody that reacts specifically with the phosphorylated tyrosine 705 of STAT3, pSTAT3(tyr705). In ALCL tumors, STAT3 was considered active when > or =20% of neoplastic cells show unequivocal nuclear immunostaining for pSTAT3(tyr705). RESULTS: All five ALK(+)ALCL cell lines showed strong pSTAT3(tyr705) expression on Western blots. In systemic ALCL, STAT3 activation was detected in 49 of 80 (61%) ALCL tumors: 26 of 31 (84%) ALK(+) tumors and 23 of 49 (47%) ALK(-) tumors. ALK expression correlated significantly with STAT3 activation (P < 0.0001). Clinical follow-up data were available for 72 patients. In the ALK(-) group, the lack of STAT3 activation correlated with a favorable 5-year overall survival (P = 0.0076) but not failure-free survival. In the ALK(+) group, patients with inactive STAT3 showed a trend toward longer overall survival (P = 0.09) and failure-free survival (P = 0.19). Importantly, all five ALK(+) ALCL patients with inactive STAT3 survived without treatment failure after a median follow-up of 83 months. CONCLUSIONS: STAT3 activation correlates with but is not strictly dependent on ALK expression in ALCL. Lack of STAT3 activation appears to correlate with a favorable clinical outcome in ALCL.

Bone marrow involvement in patients with nodular lymphocyte predominant Hodgkin lymphoma.

The significance of bone marrow involvement in patients with nodular lymphocyte predominant Hodgkin lymphoma is unknown. Of 275 patients diagnosed as lymphocyte predominant Hodgkin lymphoma at our institution (1983-2003), we identified 7 patients with purely nodular disease in the diagnostic lymph node biopsy specimen who also had bone marrow involvement. The latter was detected at the time of initial diagnosis in four patients, after one cycle of chemotherapy in one patient, and at relapse in two patients. There were six men and one woman with a median age of 37 years (range, 25-47 years). In all cases, the bone marrow was involved by large B cells, representing <10% of all cells, associated with a prominent T-cell and histiocytic background. All patients had laboratory, radiologic, and/or morphologic evidence of aggressive disease at the time of detection of bone marrow involvement. At last follow-up, four patients had died of their disease and three were alive following therapy. In conclusion, a small subset of patients in whom lymph node biopsy shows nodular lymphocyte predominant Hodgkin lymphoma with a purely nodular pattern also may have lymphoma in the bone marrow. Bone marrow involvement is associated with laboratory, radiologic, or morphologic evidence of aggressive disease and poor prognosis. Although the best terminology for these bone marrow lymphomas is uncertain, the aggressive clinical behavior of these neoplasms supports the need for intensive therapy.

Activation status of the JAK/STAT3 pathway in mantle cell lymphoma.

CONTEXT: Signal transducer and activator of transcription 3 (STAT3) is oncogenic, and we previously found evidence of constitutive STAT3 activation in a relatively small number of frozen mantle cell lymphoma (MCL) cell tumors. OBJECTIVES: To comprehensively survey the activation and phosphorylation status of STAT3 in MCL and to assess if STAT3 activation in these tumors is due to cytokine stimulation by examining the phosphorylation and activation status of Janus kinase (JAK), the physiologic activator of STAT3. DESIGN: We evaluated 43 formalin-fixed, paraffin-embedded MCL tumors using immunohistochemistry and phospho-specific antibodies against STAT3 and JAK. RESULTS: There were 37 small cell and 6 blastoid cases. There was heterogeneous expression of phospho-STAT3 (pSTAT3), with 23 negative cases (53%), 12 weakly positive cases (28%), and 8 strongly positive cases (19%). JAK3 was the only member detectable in 3 MCL cell lines, and immunoprecipitation data showed a relatively low level of tyrosine phosphorylation of JAK3 in these cells. Using immunohistochemistry, phospho-JAK3 (pJAK3) was detectable in 18 (44%) of 41 MCL tumors examined, and pJAK3 expression correlated with that of pSTAT3 (P = .008). A notable exception to this correlation was seen in the blastoid variant, since 4 (67%) of 6 blastoid cases were pSTAT3 positive but pJAK3 negative. CONCLUSIONS: We have confirmed our previous finding that STAT3 is constitutively activated in MCL tumors, with an overall frequency of 47% in this series. STAT3 activation in the small cell but not the blastoid variant of MCL is likely mediated by JAK3.

Expression of c-kit proto-oncogene product in breast tissue.

The proto-oncogene c-kit encodes a transmembrane tyrosine kinase growth factor receptor. Stem cell factor, the receptor ligand, plays an important role in the development of certain neoplasms. c-kit is selectively and competitively bound by STI-571, a newly developed tyrosine kinase inhibitor. Several investigators report conflicting results concerning its expression, especially in malignant breast lesions. The objective of this study was to better characterize the expression of c-kit within the spectrum of breast epithelium (normal breast epithelium, nonneoplastic lesions, and breast carcinoma). Seventy-seven randomly selected breast tissue samples, each containing normal breast epithelium (21), invasive breast carcinoma (41), in situ breast carcinoma (29), papilloma (8), fibroadenoma (5), fibrocystic change (11), and/or metastatic breast carcinoma (4), were immunostained with polyclonal rabbit antihuman c-kit (Dako, Carpenteria, CA) at a dilution of 1:200. The staining was interpreted as negative if no cells were immunoreactive, weak positive if 5% of the cells were immunoreactive, and positive if more than 5% of the cells were immunoreactive. Appropriate positive and negative controls were used. The observed staining was cytoplasmic, with highlighting of the nuclear membrane. Normal breast epithelium was positive in all cases. More than half of the cases of hyperplastic changes and benign neoplasms (fibroadenoma and papilloma) were positive. Only 10% of invasive and in situ carcinomas showed positivity for c-kit. c-kit is consistently expressed in normal breast epithelium, variably expressed in benign breast lesions, and poorly expressed in breast carcinoma. These data suggest that c-kit may play a role in breast tumor progression and may therefore have diagnostic, prognostic, and therapeutic implications.