Ken Gatter

The New Equivocal: Changes to HER2 FISH Results When Applying the 2013 ASCO/CAP Guidelines.

OBJECTIVES Human epidermal growth factor receptor 2 (HER2, ERBB2) testing is an important prognostic/predictive marker in breast cancer management, especially in selecting HER2-targeted treatment. American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines address HER2 status and were recently revised in 2013, replacing the 2007 version. For in situ hybridization interpretation, 2013 guidelines return to the prior threshold of a HER2/CEP17 ratio of 2.0 or greater for positive and eliminate 1.8 to 2.2 as the equivocal range. Also, the HER2 signal/nucleus ratio is accounted for, with 6.0 or greater for positive and 4.0 to less than 6.0 for equivocal, even in cases with a HER2/CEP17 ratio less than 2.0. METHODS With institutional review board approval, we reviewed our 2006 to 2012 HER2 fluorescence in situ hybridization (FISH) results and classified them according to both the 2007 and 2013 guidelines as negative, positive, or equivocal. RESULTS Of 717 HER2 FISH results, 55 (7.7%) changed category when reassessed by 2013 guidelines. Nineteen of 25 results in the 2007 equivocal category were reassigned as positive (n = 13) or negative (n = 6). Thirty-five previously negative cases became equivocal in the 2013 scheme, 12 of these with 1+ immunohistochemistry. The positive category increased from 71 to 85. CONCLUSIONS The 2013 ASCO/CAP guidelines increased the number of HER2 FISH positive and equivocal results. The equivocal group is substantially different, posing a dilemma for clinical management.

Immunophenotypic Variations of Burkitt Lymphoma

Burkitt lymphoma (BL) exhibits a characteristic immunophenotype that is positive for pan-B-cell antigens and CD10 and expresses clonal surface immunoglobulins (SIgs). We evaluated 35 BLs and identified atypical immunophenotypes in 4 including SIg light chain negativity in 4, negativity for B-cell antigens in 2, lack of CD10 in 1, and CD4 expression in 1. All 4 cases showed morphologic features characteristic of BL, and all were confirmed by cytogenetic analysis. The 4 BL cases included 1 girl, 2 men with HIV/AIDS, and a third man with a history of heart transplantation. Two patients died shortly after diagnosis; the other 2 completed hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone with highly active antiretroviral therapy and achieved complete remission. Our study indicates that an unusual immunophenotype is not uncommon in BL. If the immunophenotype is interpreted in isolation, the diagnosis could be missed. Recognizing the variability of immunophenotype is essential for establishing an accurate diagnosis of BL.

Diagnostic pitfalls in syringocystadenocarcinoma papilliferum: case report and review of the literature.

We report the first case, to our knowledge, of syringocystadenocarcinoma papilliferum with p63-verified squamous differentiation and extensive dermal invasion accompanying in situ components. An 86-year-old woman presented with a neoplasm on the neck, and the intralesional heterogeneity typical of these neoplasms led to an initial diagnosis on needle biopsy favoring squamous cell carcinoma. Excision illustrated diverse morphology, raising a broad differential diagnosis, including more common extracutaneous malignancies, such as breast, gastrointestinal, and ovarian primary tumors. Fortuitous sectioning revealed a focal connection to the skin surface with evidence of apocrine differentiation allowing final diagnosis as syringocystadenocarcinoma papilliferum. Our literature review shows the histologic and immunohistochemical features of syringocystadenocarcinoma papilliferum are not well defined outside of their clear morphologic overlap with syringocystadenoma papilliferum. We describe our findings and diagnostic pitfalls to help pathologists encountering this unusual apocrine neoplasm.

Multiplex high-throughput gene mutation analysis in acute myeloid leukemia

Classification of acute myeloid leukemia increasingly depends on genetic analysis. However, the number of known mutations in acute myeloid leukemia is expanding rapidly. Therefore, we tested a high-throughput screening method for acute myeloid leukemia mutation analysis using a multiplex mass spectrometry-based approach. To our knowledge, this is the first reported application of this approach to genotype leukemias in a clinical setting. One hundred seven acute myeloid leukemia cases were screened for mutations using a panel that covers 344 point mutations across 31 genes known to be associated with leukemia. The analysis was performed by multiplex polymerase chain reaction for mutations in genes of interest followed by primer extension reactions. Products were analyzed on a Sequenom MassARRAY system (San Diego, CA). The multiplex panel yielded mutations in 58% of acute myeloid leukemia cases with normal cytogenetics and 21% of cases with abnormal cytogenetics. Cytogenetics and routine polymerase chain reaction-based screening of NPM1, CEBPA, FLT3-ITD, and KIT was also performed on a subset of cases. When combined with the results of these standard polymerase chain reaction-based tests, the mutation frequency reached 78% in cases with normal cytogenetics. Of these, 42% harbored multiple mutations primarily involving NPM1 with NRAS, KRAS, CEBPA, PTPN11, IDH1, or FLT3. In contrast, cases with abnormal cytogenetics rarely harbored more than 1 mutation (1.5%), suggesting different underlying biology. This study demonstrates the feasibility and utility of broad-based mutation profiling of acute myeloid leukemia in a clinical setting. This approach will be helpful in defining prognostic subgroups of acute myeloid leukemia and contribute to the selection of patients for enrollment into trials with novel inhibitors.

Diagnostic usefulness of aberrant CD22 expression in differentiating neoplastic cells of B-cell chronic lymphoproliferative disorders from admixed benign B cells in four-color multiparameter flow cytometry

The diagnosis of B-cell chronic lymphoproliferative disorders is a great challenge when made in a background of polyclonal B cells. We studied the diagnostic usefulness of aberrant CD22 expression for differentiating neoplastic from benign B cells by 4-color flow cytometry. Of 56 cases of B-cell chronic lymphoproliferative disorders, we found that neoplastic cells showed aberrant CD22 expression in 39 (70%) of 56 cases, including chronic lymphocytic leukemia, mantle cell lymphoma, marginal zone lymphoma, hairy cell leukemia, and follicular lymphoma. In 4 cases, monoclonality was detected definitively only by evaluating the immunoglobulin light chain restriction in B cells with aberrant CD22 expression because numerous polyclonal B cells were present. Aberrant CD22 expression is a useful marker for detection of monoclonal B cells admixed with numerous benign polyclonal B cells.

Significant understaging is seen in clinically staged T2N0 esophageal cancer patients undergoing esophagectomy

This study aimed to determine the impact of preoperative staging on the treatment of clinical T2N0 (cT2N0) esophageal cancer patients undergoing esophagectomy. We reviewed a retrospective cohort of 27 patients treated at a single institution between 1999 and 2011. Clinical staging was performed with computed tomography, positron emission tomography, and endoscopic ultrasound. Patients were separated into two groups: neoadjuvant therapy followed by surgery (NEOSURG) and surgery alone (SURG). There were 11 patients (41%) in the NEOSURG group and 16 patients (59%) in the SURG group. In the NEOSURG group, three of 11 patients (27%) had a pathological complete response and eight (73%) were partial or nonresponders after neoadjuvant therapy. In the SURG group, nine of 16 patients (56%) were understaged, 6 (38%) were overstaged, and 1 (6%) was correctly staged. In the entire cohort, despite being clinically node negative, 14 of 27 patients (52%) had node-positive disease (5/11 [45%] in the NEOSURG group, and 9/16 [56%] in the SURG group). Overall survival rate was not statistically significant between the two groups (P = 0.96). Many cT2N0 patients are clinically understaged and show no preoperative evidence of node-positive disease. Consequently, neoadjuvant therapy may have a beneficial role in treatment.

Immunophenotypic Correlation Between Skin Biopsy and Peripheral Blood Findings in Mycosis Fungoides

In mycosis fungoides (MF) with blood involvement, T-cell immunophenotypes in skin and blood have not been compared. Our aim was to evaluate T-cell immunophenotypes in skin by immunohistochemical analysis and compare results with flow cytometric (FC) findings in blood. Of 20 patients with MF with blood involvement, the immunophenotype was discrepant in 11 (55%). Compared with FC findings in blood, immunohistochemical analysis of skin samples failed to detect partial deletion of CD2 (5/11 [45%]), CD3 (3/11 [27%]), and CD5 (3/11 [27%]) and overrepresented deletion of CD7 in 2 (18%) of 11 patients. In addition, CD8+ MF was missed by immunohistochemical analysis in 2 (18%) of 11 patients. Identical T-cell populations were demonstrated by T-cell gene polymerase chain reaction in skin and blood in 8 of the 11 patients who had a discrepant immunophenotype. Awareness of the limitations of immunohistochemical analysis of skin samples is of practical value for pathologists interpreting skin biopsies in MF patients. In addition, our findings suggest CD8+ MF to be more common than previously reported.

Association of JAK2 Mutation Status and Cytogenetic Abnormalities in Myeloproliferative Neoplasms and Myelodysplastic/Myeloproliferative Neoplasms

Myeloproliferative neoplasms and myelodysplastic/myeloproliferative neoplasms are heterogeneous disorders. JAK2 mutation testing and karyotyping are routinely used for diagnosis but have not been incorporated into risk stratification in Philadelphia chromosome-negative myeloproliferative neoplasms. This study correlated cytogenetic abnormalities with disease stage and JAK2 status. A total of 179 cases were analyzed for the JAK2 mutation. Among them, cytogenetic data were available for 97 cases-45 of 106 JAK2+ and 52 of 73 JAK2-. The JAK2+ group showed a higher frequency of cytogenetic anomalies than the JAK2- group (23/45 [51%] vs 14/52 [27%]). Chromosome 9, chromosome 7, and 20q- were recurrent abnormalities in the JAK2+ group, whereas 13q- and trisomy 21 were common in the JAK2- group. In the JAK2+ group, chromosome 7 and complex cytogenetic abnormalities were associated with excess blasts/blastic transformation (P < .05), whereas no cases with 20q- underwent blastic transformation. Our results suggest that incorporation of JAK2 mutation testing and karyotyping allows for monitoring of disease progression with prognostic and therapeutic implications.

Association of Intervals Between Neoadjuvant Chemoradiation and Surgical Resection With Pathologic Complete Response and Survival in Patients With Esophageal Cancer.

Importance Pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (CRT) may be a clinical prognostic marker of superior outcomes. In patients with esophageal cancer, pCR is associated with increased survival. While mechanisms for increasing the likelihood of pCR remain unknown, in other solid tumors, higher rates of pCR have been associated with longer time intervals between CRT completion and surgical procedures. Objective To determine the association between time intervals from the completion of CRT to surgical procedure with rates of pCR in patients with esophageal cancer. Design, Setting, and Participants A prospectively maintained multidisciplinary foregut database was reviewed for consecutively enrolled patients with esophageal cancer from January 2000 to July 2015 presenting for surgical evaluation at a single National Cancer Institute-designated cancer center within a quaternary academic medical center. Interventions Included patients successfully completed neoadjuvant CRT followed by esophagectomy. Main Outcomes and Measures Rate of pCR by logistic regression based on a categorized time interval (ie, 0 to 42, 43 to 56, 57 to 70, 71 to 84, 85 to 98, and 99 or more days) from the completion of CRT to surgical resection, adjusted for clinical stage, demographic information, and CRT regimen. Results Of the 234 patients who met inclusion criteria, 191 (81.6%) were male, and the median (range) age was 64 (58-70) years; 206 (88.0%) were diagnosed as having adenocarcinoma, and 65 (27.9%) had a pCR. Patients in the 85 to 98-day group had significantly increased odds of a pCR compared with other groups (odds ratio, 5.46; 95% CI, 1.16-25.68; P = .03). No significant differences in survival were seen between time groups overall or among patients with residual tumor. Conclusions and Relevance This study suggests that a time interval of 85 to 98 days between CRT completion and surgical resection is associated with significantly increased odds of a pCR in patients with esophageal cancer. No adverse association with survival was detected as a result of delaying resection, even in patients with residual tumor.

Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios can Predict Treatment Response to Neoadjuvant Therapy in Esophageal Cancer.

IntroductionWe hypothesized that serum neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios may predict pathologic complete response to neoadjuvant chemoradiotherapy in esophageal cancer patients. The ability to predict favorable treatment response to therapy may aid in determining optimal treatment regimens.Materials and MethodsA retrospective review of a prospective esophageal disease registry was conducted. Neutrophil-to-lymphocyte ratio was defined as the pre-chemoradiotherapy serum neutrophil count divided by lymphocyte count. Platelet-to-lymphocyte ratio was similarly defined. Logistic regression was applied to analyze these ratios and their effect on pathologic complete response. A Cox proportional-hazards model was used to analyze survival.ResultsSixty patients were included. Elevated neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were both negative predictors of pathologic complete response (odds ratio: 0.62; 95% confidence interval: 0.37–0.89, P = 0.037 and odds ratio: 0.91; 95% confidence interval: 0.82–0.98, P = 0.028, respectively). Only platelet-to-lymphocyte ratio was predictive of decreased overall survival (hazard ratio: 1.05, 95% confidence interval: 0.94–1.16, P = 0.40).ConclusionElevated neutrophil and platelet-to-lymphocyte ratios were significant predictors of a poor treatment response to neoadjuvant therapy. Only elevated platelet-to-lymphocyte ratio was predictive of worse overall survival. Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios may offer a simple serum test to assess the likelihood of a pathologic complete response after neoadjuvant therapy in esophageal cancer.