Prognostic implications of abnormalities of chromosome 13 and the presence of multiple cytogenetic high-risk abnormalities in newly diagnosed multiple myeloma.

Fluorescence in situ hybridization evaluation is essential for initial risk stratification in multiple myeloma. While the presence of specific cytogenetic high-risk abnormalities (HRA) is known to confer a poor prognosis, less is known about the cumulative effect of multiple HRA. We studied 1181 patients with newly diagnosed multiple myeloma who received novel agents as first-line therapy. High-risk abnormalities were defined as t(4;14), t(14;16), t(14;20) and del(17p). There were 884 patients (75%) without any HRA and 297 patients (25%) with HRA, including 262 (22%) with one HRA and 35 (3%) with two HRA. The presence of one HRA (versus zero, hazard ratio (HR) 1.65, 95% confidence interval (CI) 1.32-2.05, p<0.001) and the presence of two HRA (versus zero, HR 3.15, 95% CI 2.00-4.96, p<0.001) were of prognostic significance after adjusting for other prognostic factors. Abnormalities of chromosome 13 were of prognostic significance independent of the established HRA: Monosomy 13 (HR 1.27, 95% CI 1.04-1.56, P=0.022) and del(13q) (HR 0.48, 95% CI 0.28-0.81, P=0.006) with opposite effects. Patients with HRA experienced worse overall survival suggesting a cumulative adverse effect of multiple HRA. Abnormalities of chromosome 13 were of prognostic significance after adjusting for other prognostic factors.

Adenoid cystic carcinoma of the lacrimal gland is frequently characterized by MYB rearrangement.

PurposeAdenoid cystic carcinoma (ACC) represents ~10-15% of salivary neoplasms and almost universally exhibits a lethal clinical course. ACC is also known to occur in the lacrimal gland. ACC is characterized by its heterogeneous morphology and may demonstrate tubular, cribriform, and/or solid architectural patterns. Unfortunately, these histopathological features are not specific to ACC and can be seen in other salivary gland-type neoplasms, introducing a diagnostic dilemma. The discovery of fusion transcripts has revolutionized the diagnosis, surveillance, and treatment of epithelial malignancies. In several anatomic subsites ACC is frequently characterized by a fusion transcript involving genes MYB and NFIB; more specifically, t(6;9)(q22-23;p23-24). This study explores the incidence of MYB rearrangement in cases of lacrimal gland ACC using fluorescent in situ hybridization.Materials and methodsRetrospective clinical and histopathological review of 12 cases of lacrimal gland ACC seen at Mayo Clinic over a 25-year period (1990-2015) was performed. Demographic and clinical data were obtained from medical records. Surgical pathology archival material including H&E slides and immunostains was re-examined. Formalin-fixed paraffin-embedded material was further evaluated using immunohistochemistry when appropriate. Fluorescent in situ hybridization (FISH) using a MYB break-apart probe was applied to all histologically confirmed cases of ACC and benign salivary gland parenchyma.ResultsThe median patient age was 53.6 years (range 12-64) and distributed equally by gender (six male and six female). Rearrangement of MYB was identified using FISH in seven cases (58%). Twenty-five sections of benign salivary gland parenchyma showed no evidence of MYB rearrangement. Primary surgical resection was most common treatment, and 78% of the patient received adjuvant radiation therapy. Median overall survival (OS) was 11 years. Rearrangement of MYB did not affect OS.ConclusionsIn summary, our results indicate that the MYB rearrangement defines a significant subset of lacrimal gland ACCs. Importantly, FISH for MYB rearrangement may be used as a diagnostic tool during pathological examination of lacrimal gland neoplasms. Our results showed no relationship between rearrangement status and clinical outcome. Lastly, the presence of t(6;9) in ACC may provide a platform for molecular-targeting strategies in the future.