Understanding of the genetic basis and molecular pathogenesis of cancer has evolved substantially over the past century. The advent of high-throughput gene sequencing methods has unraveled hundreds of recurrent somatic genetic alterations in various malignancies, either causative or harboring major prognostic and/or predictive implications. Knowledge of these specific changes has dramatically altered diagnostic and therapeutic approaches to cancer, enabling personalized molecular therapies. This article shares approaches to adopting and fine-tuning the practice of molecular diagnostics as an essential component of diagnostic pathology in a tertiary care cancer hospital and proposes methods by which genetic testing in cancer can become standard of care in pathology departments across the nation.
Sanam Loghavi, Mark J. Routbort, Keyur P. Patel, Rajyalakshmi Luthra, Wei-Lien Wang, Russell R. Broaddus, Michael A. Davies, and Alexander J. Lazar
C. Cameron Yin, Nitin Jain, Meenakshi Mehrotra, Jianhua Zhagn, Alexei Protopopov, Zhuang Zuo, Naveen Pemmaraju, Courtney DiNardo, Cheryl Hirsch-Ginsberg, Sa A. Wang, L. Jeffrey Medeiros, Lynda Chin, Keyur P. Patel, Farhad Ravandi, Andrew Futreal, and Carlos E. Bueso-Ramos
Acute promyelocytic leukemia (APL) is characterized by the fusion of retinoic acid receptor alpha (RARA) with promyelocytic leukemia (PML) or, rarely, other gene partners. This report presents a patient with APL with a novel fusion between RARA and the interferon regulatory factor 2 binding protein 2 (IRF2BP2) genes. A bone marrow examination in a 19-year-old woman who presented with ecchymoses and epistaxis showed morphologic and immunophenotypic features consistent with APL. PML oncogenic domain antibody was positive. Results of fluorescence in situ hybridization, conventional cytogenetics, reverse transcription–polymerase chain reaction (RT-PCR), and oligonucleotide microarray for PML-RARA and common APL variant translocations were negative. Next-generation RNA-sequencing analysis followed by RT-PCR and direct sequencing revealed distinct breakpoints within IRF2BP2 exon 2 and RARA intron 2. The patient received all-trans retinoic acid, arsenic, and gemtuzumab ozogamicin, and achieved complete remission. However, the disease relapsed 10 months later, 2 months after consolidation therapy. This is the first report showing involvement of IRF2BP2 in APL, and it expands the list of novel RARA partners identified in APL.
Sanjeev Kumar Gupta, Nitin Jain, Guilin Tang, Andrew Futreal, Sa A. Wang, Joseph D. Khoury, Richard K. Yang, Hong Fang, Keyur P. Patel, Rajyalakshmi Luthra, Mark Routbort, Bedia A. Barkoh, Wei Chen, Xizeng Mao, Jianhua Zhang, L. Jeffrey Medeiros, Carlos E. Bueso-Ramos, and Sanam Loghavi
RNA-seq was used to identify the partner gene and confirm the presence of a BCR-PDGFRB fusion. Identification of this fusion product resulted in successful treatment and long-term remission of this myeloid neoplasm. Based on our results, we suggest that despite current WHO recommendations, screening for PDGFRB rearrangement in cases of leukocytosis with eosinophilia and no other etiologic explanation is necessary, even if the karyotype is normal.