Isolated del(5q) in Patients Following Therapies for Various Malignancies May Not All Be Clinically Significant

• Published in: American journal of clinical pathology 2015-07, Vol.144 (1), p.78-86
• Main Authors: Tang, Guilin, Goswami, Rashmi Shivani, Liang, Cynthia S., Bueso-Ramos, Carlos E., Hu, Shimin, DiNardo, Courtney, Medeiros, L. Jeffrey
• Format: Article
• Language: English
• Subjects: Aged; Antineoplastic Agents - adverse effects; Chromosome Deletion; Chromosomes, Human, Pair 5 - genetics; Female; Hematologic Neoplasms - genetics; Humans; In Situ Hybridization, Fluorescence; Male; Middle Aged; Neoplasms - therapy; Neoplasms, Second Primary - genetics; Neoplasms, Second Primary - pathology
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1309/AJCPBADO22WXOFHJ

Objectives: Deletion 5q is a common chromosomal abnormality in both de novo and therapy-related myeloid neoplasms (t-MNs). The detection of isolated del(5q) in patients following therapies for various malignancies raises serious concern for an emerging t-MN. Methods: We identified 25 patients who developed isolated del(5q) following cytotoxic therapy (n = 21) or tyrosine kinase inhibitor (TKI; n = 4) therapy. Twenty-four patients had an interstitial and one had a terminal 5q deletion. The 5q31/EGR1 gene was deleted in 20 patients and intact in five patients. The clone size as assessed by metaphase analysis was minor (10%–30%) in 12 patients and large (45%–100%) in 13 patients. After a median follow-up of 17 months, none of the 12 patients with a minor del(5q) clone developed t-MN; del(5q) disappeared in four patients and persisted in eight patients. By contrast, 12 of 13 patients with a large del(5q) clone developed t-MN, and del(5q) was persistent in all patients who had follow-up cytogenetic testing. Conclusions: Development of del(5q) in patients following cytotoxic therapies or TKI may not always be associated with t-MN. A close follow-up seems an appropriate approach for patients who had a minor del(5q) clone.