Cytogenetics and Revised International Staging System (R-ISS): Risk Stratification in Multiple myeloma - A Retrospective Study in Indian Population

Cytogenetic abnormalities in Multiple myeloma (MM) has emerged as the most important factor that determine the prognosis and survival. Fluorescence in situ hybridization (FISH) can detect a greater number of cytogenetic abnormalities as compared to conventional karyotyping and hence has become the standard test in determining genetic abnormalities in MM. The present study was planned as there is an unmet need to find out various cytogenetic abnormalities and to implement them in prognostic stratification by Revised International Staging System (R-ISS) among Indian population.

A single institution retrospective study was conducted among a total of 117 patients newly diagnosed as Multiple Myeloma. They were analyzed for various cytogenetic abnormalities by using interphase FISH (iFISH) and were staged according to Revised International Staging System (R- ISS).

Out of the 117 patients studied, deletion 17p13 (p53) was present in 16 patients (13.67%).  Thirty patients (25.64%) showed deletion 13q14.3. Three patients (2.56%) were detected to have t(4:14).Two patients (1.7%) had t(11:14) and t(14:16), respectively. Total of 19 patients (16.23%) in our study exhibited high risk cytogenetics and two among them had more than one high risk cytogenetic abnormalities. There was a 66.4% moderate correlation between ISS-III and high-risk cytogenetics which was statistically insignificant. Of the total 117 patients, 37 (31.62%) were staged R-ISS III.

High risk cytogenetics was found in 16.23 % of our study population and del 17p13 was the most common high-risk cytogenetic abnormality. Of the studied subjects, 31.62% had R-ISS III, which is significantly higher compared to western population.