Utility and Impact of Early t(15:17) Identification by Fluorescence In Situ Hybridization (FISH) in Clinical Decision Making for Referral Patients in Acute Promyelocytic Leukemia (APML)
Ravindra Kolhe, Amyn Rojiani, Anand Jillella, Vamsi Kota, Lora Walczak, Jennifer Shaw, Barbara DuPont. Georgia Health Sciences University, Augusta, GA
Background: SEER data analysis from 13 population based cancer registries with 1400 APML patients in the US showed that 17% of all & 24% of patients >55 years of age die within 1 month of diagnosis. Early initiation of treatment is critical in improving outcomes. The key point in this algorithm is early detection of t(15:17). This is especially true for patient's referred to a cancer center from rural areas. The aim of this project was to validate shorter hybridization times for the use of the Abbott Molecular Vysis LSI PML/RARA FISH probe(ASR 6-16 hrs.).
Design: 6 patients (AML-M0,M1, Leukocytosis, NHL, pregnancy loss, & APML) were selected for validating various hybridization (hybe) times. All manufacture's guidelines and standard protocol for FISH were followed. 200 cells with robust signals were identified & recorded. Hybe efficiency was graded as acceptable, intermediate & unacceptable. Expected normal signal pattern was 2 red and 2 green signals (2R2G), & the expected most common abnormal signal pattern were 2F1R1G &/or 1F1R1G.
Results: The specificity of probe remained 100% for all incubation times, but the sensitivity increased from 95% at 2hrs to 98% overnight hybe which was expected.
Conclusions: In patients with co-morbid conditions the use of All-Trans Retinoic acid (ATRA) is cautioned, arsenic is the treatment of choice pending confirmation of the diagnosis.This delay in diagnosis may increase the risk of early mortality in patients with high risk(HR) and with co-morbid conditions. The uitility of early t(15:17) detection by FISH helped in intiating ATRA /chemotherapy early, especially in the HR group. From 11/10- 12/11, we treated 5 patients at GHSU and helped manage 5 patients at 3 outreach sites. There were no deaths during induction and all patients proceeded to consolidation treatment. Early identification of t(15:17) will lead to improvement in outcomes with earlier initiation of treatments. Based on the validation studies the current recommendations are to read the FISH results at 4 hour incubation with a preliminary diagnosis and confirmation by with overnight hybe.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 230, Wednesday Morning