Abstract 639P
Background
Overall Survival (OS) estimates from diagnosis are important for predicting prognosis and guiding treatment selection in newly diagnosed patients, but do not consider the number of years already survived. Conditional survival (CS) estimates provide updated survival predictions over the disease course. Previous studies suggest that improvement in CS is less pronounced in multiple myeloma (MM) compared to other malignancies. It is unclear whether high-risk (HR) factors in MM retain their prognostic impact over time. This study was conducted to estimate CS at 1 to 5 years from diagnosis and evaluate the impact of baseline prognostic factors on CS over time in newly diagnosed MM patients.
Methods
This is a retrospective study including 2556 MM patients diagnosed between 2004-2019. CS (t|s), defined as the probability of surviving additional t years given survival of s years, was estimated at 1 to 5 years from diagnosis using the conditional Kaplan-Meier method. The impact of baseline characteristics on CS was estimated using conditional Cox proportional hazards model.
Results
The median age was 64 years and 62% were male; >90% received novel-agent based induction; 46% had transplant within 1 year of diagnosis. The median follow-up was 6.2 years, and median OS was 7.5 years. The 5-year CS estimates at s=0, 1, 2, 3, and 5 years were 0.64, 0.61, 0.61, 0.61, and 0.58, respectively. On multivariate analysis, age ≥ 65 and proteasome inhibitor (PI)+Immunomodulatory (IMiD)-based induction retained prognostic significance at 5 years from diagnosis. The adverse impact of HR IgH translocations, 1q gain and ISS 3 was not significant at 5 years. Chromosome 17 abnormality predicted worse CS at 1 year, but not at 3 or 5 years from diagnosis (table). Table: 639P
Multivariate CS
| Variable | Diagnosis | year 1 | year 3 | year 5 | ||||
| HR | P | HR | P | HR | P | HR | P | |
| Age≥65 | 1.60 | <0.01 | 1.57 | <0.01 | 1.48 | <0.01 | 1.95 | <0.01 |
| Calcium ≥11 | 1.59 | <0.01 | 1.63 | <0.01 | 1.05 | NS | 1.05 | NS |
| ISS III | 1.74 | <0.01 | 1.75 | <0.01 | 1.80 | <0.01 | 1.52 | NS |
| Early transplant | 0.57 | <0.01 | 0.64 | <0.01 | 0.61 | <0.01 | 0.69 | NS |
| PI+IMiD induction | 0.59 | <0.01 | 0.63 | 0.01 | 0.66 | 0.04 | 0.53 | 0.04 |
| LDH > 222 | 1.29 | NS | 1.15 | NS | 1.13 | NS | 0.89 | NS |
| Ch17 abnormality | 1.53 | <0.01 | 1.43 | 0.02 | 1.32 | NS | 1.16 | NS |
| HR IgH translocation | 1.90 | <0.01 | 1.97 | <0.01 | 1.55 | 0.04 | 1.51 | NS |
| Monosomy 13 | 1.13 | NS | 1.09 | NS | 1.05 | NS | 0.86 | NS |
| 1q gain | 1.34 | <0.01 | 1.31 | 0.03 | 1.50 | 0.01 | 1.38 | NS |
Significant P values are bolded. NS: not significant.
Conclusions
In a large cohort of MM patients treated with novel agents, CS was stable at 1 to 5 years from diagnosis. The adverse prognostic impact of HR cytogenetic factors and advanced ISS stage decreased over time.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
P. Kapoor: Other, Funding, Research funding: Takeda, Celgene, Amgen. A. Dispenzieri: Other, Funding, Research Funding: Celgene, Millennium Pharmaceuticals, Pfizer, Janssen; Other, Travel grant: Pfizer. M. Gertz: Other, Honoraria: Millennium Pharmaceuticals, Amgen, Ionis Pharmaceuticals, Prothena, GlaxoSmithKline, Novartis, Onyx Pharmaceuticals, Celgene; Other, Consultant: Millennium Pharmaceuticals. S. Kumar: Other, Consultant and Research funding: Onyx Pharmaceuticals, Celgene, Millennium Pharmaceuticals, Janssen, Bristol-Myers Squibb; Other, Research funding: Novartis, AbbVie. All other authors have declared no conflicts of interest.