Long-term prognostic impact of chromosome 1 abnormalities in newly diagnosed multiple myeloma patients: a monocentric study

The presence of chromosome 1 abnormalities in multiple myeloma (MM) has been included in the more recent prognostic staging system; however, the prognostic role of chromosome 1 abnormalities remains controversial. Thus, in this study we have investigated the prognostic role of chromosome 1 abnormalities in a cohort of newly diagnosed MM (NDMM), performing a retrospective monocentric analysis of 95 patients. Median follow up was 66 months for overall survival (OS) and progression free survival (PFS), and 55 months for time to next treatment (TTNT). Univariate analyses showed that 1q gain or amplification did not significantly affect outcomes (OS p=0.30; PFS p=0.69; TTNT p=0.91). Conversely, del(1p) was associated with inferior OS (p=0.015), PFS (p=0.007), and TTNT (p=0.038), although this effect did not persist in multivariable models. Notably, the co occurrence of del(1p) and del(17p) identified a subgroup with markedly worse prognosis across all endpoints and represented the only combination with a consistent additive adverse effect. Multivariable analyses confirmed that patients harboring both abnormalities had significantly poorer outcomes, including reduced OS (HR 6.97, 95% CI 2.94-16.54), PFS (HR 6.92, 95% confidence interval [CI] 2.89-16.55), and TTNT (HR 5.21, 95% CI 1.69-16.05. In conclusion, our study suggests that among the cytogenetic abnormalities, del(1p) is a significant negative prognostic factor in NDMM patients in combination with the presence of del(17p), in shaping the prognosis of NDMM.