A predictive risk-scoring model for survival prognosis of multiple myeloma based on gain/amplification of 1q21: Experience in a tertiary hospital in South-Western China

Background

Chromosomal 1q gains and amplifications (+1q21) are frequently observed in patients with newly diagnosed multiple myeloma (NDMM). However, the interpretation of the high-risk (HR) prognostic implications stemming from 1q21 abnormalities remain challenging to implement effectively.

Methods

In a comprehensive analysis of 367 consecutive patients with symptomatic MM, we assessed the prognostic significance of +1q21 using FISH with a threshold of 7.4%. The patient cohort was randomly divided into a training set (66.5%, n = 244) and a validation set (33.5%, n = 133). A multivariate Cox regression analysis was conducted to identify significant prognostic factors associated with PFS. Weight scores were assigned to each risk factor based on the β-value of the corresponding regression coefficient. A predictive risk-scoring model involving +1q21 was then developed, utilizing the total score derived from these weight scores. The model's discriminative ability was evaluated using the AUC in both the training and validation sets. Finally, we compared the performance of the +1q21-involved risk with the established R-ISS and R2-ISS models.

Results

Upon initial diagnosis, 159 patients (43.32%) exhibited +1q21, with 94 (59.11%) having three copies, referred to as Gain(1q21), and 65 (40.89%) possessing four or more copies, referred to as Amp (1q21). Both were significantly linked to a reduced PFS in myeloma (p < 0.05), which could be effectively mitigated by ASCT. The +1q21-involved risk model, with an AUC of 0.697 in the training set and 0.725 in the validation set, was constructed including Gain(1q21), Amp(1q21), no-ASCT, and TP53 deletion. This model, termed the ultra-high-risk (UHR) model, demonstrated superior performance in predicting shorter PFS compared to the R-ISS stage 3 and R2-ISS stage 4.

Conclusion

The UHR model, which integrates the presence of +1q21 with no-ASCT and TP53 deletion, is designed to identify the early relapse subgroup among patients with +1q21 in NDMM.