Analysis Of Prognostic Risk Factors For Newly Diagnosed Multiple Myeloma:Construction And Validation Of Prognostic Model

Objective:To explore the prognostic risk factors of patients with newly diagnosed multiple myeloma and to construct and validate a nomogram prognostic model.Methods:1.152 newly diagnosed patients with multiple myeloma who were treated in the First Hospital of Lanzhou University from January 2017 to July 2022 were included.2.To analyze the differences in clinical characteristics and survival between patients with high and low hematopoietic cell transplantation-comorbidity index（HCT-CI）scores.3.Cox univariate and multivariate regression analysis were performed.A predictive model in the form of a nomogram was developed to estimate the survival and prognosis of individuals with newly diagnosed multiple myeloma（NDMM）,utilizing the results obtained from a multivariate Cox regression analysis.4.The nomogram was assessed and validated using various statistical measures such as concordance index（C-index）,receiver operating characteristic（ROC）curve,area under the ROC curve（AUC）,calibration curve,and decision curve analysis（DCA）.Patients were finally risk stratified according to the total model score and validated in combination with ISS/R-ISS stage,age,and gender.Results:1.According to the HCT-CI score,the patients can be divided into high and low score groups.Overall survival was better in the low score group than in the high score group（P=0.003）.There are statistically significant differences in red blood cell count,hemoglobin,serum creatinine,β₂-microglobulin,and the proportion of bone marrow plasma cells（P<0.05）,which are indicators of high tumor burden.At the same time,The ISS stage was found to be significantly later in the high HCT-CI score group compared to those in low score group（P<0.01）.2.Cox multivariate analysis showed that the age at diagnosis was≥65 years old,the HCT-CI score was>1 point,and the LDH was higher than the normal（>240U/L）and the proportion of bone marrow plasma cells>21.25%are independent adverse prognostic factors of Overall survival（OS）in patients with newly diagnosed multiple myeloma.3.Age at diagnosis,HCT-CI score,LDH and the proportion of bone marrow plasma cells were included to construct a nomogram prediction model.The C-index of the Nomogram prediction model for OS was 0.651,which was superior than that of the ISS staging system（C-index=0.551）.The ROC curve showed that the nomogram showed good discrimination,and the areas under the ROC curve at 1,3,and 5 years were 0.690,0.767,and 0.758,respectively.The calibration curve and DCA also demonstrated that the nomogram prediction model had good consistency and clinical practicability.4.The model effectively stratified patients into low-risk group and high-risk group.The median OS is 994 days and 625 days respectively（P<0.001）.Risk stratification survival analysis with further risk stratification among ISS stage,R-ISS stage and different age and gender was statistically significant（P<0.05）.Conclusion:1.HCT-CI score,age at diagnosis,LDH,and bone marrow plasma cell ratio are independent adverse prognostic factors for OS of NDMM patients.2.Patients with a high HCT-CI score differed from patients with a low HCT-CI score in several measures of high tumor burden and ISS stage.The overall survival of the low HCT-CI score group was better than that of the high HCT-CI score group.3.It is confirmed that the nomogram prognostic model constructed on the basis of HCT-CI to predict the 1-year,3-year,and 5-year OS rate of NDMM patients could predict the survival prognosis well.The risk stratification of the model was able to discriminate the high-risk patients well.