Photo by Rhoda Baer
Cancer patient receiving treatment
A retrospective study suggests one in seven patients with newly diagnosed multiple myeloma (MM) who are eligible for transplant may live at least as long as similar individuals in the general population.
The study included more than 7,000 MM patients, and 14.3% of those patients were able to meet or exceed their expected survival based on data from matched subjects in the general population.
Researchers believe that figure may be even higher today, as more than 90% of patients in this study were treated in the era before novel therapies became available.
Saad Z. Usmani, MD, of the Levine Cancer Institute/Atrium Health in Charlotte, North Carolina, and his colleagues described this study in Blood Cancer Journal.
The researchers studied 7,291 patients with newly diagnosed MM who were up to 75 years old and eligible for treatment with high-dose melphalan and autologous stem cell transplant. The patients were treated on clinical trials in 10 countries.
Factors associated with survival
Patients who had achieved a complete response (CR) 1 year after diagnosis had better median progression-free survival (PFS) than patients who did not achieve a CR—3.3 years and 2.6 years, respectively (P<0.0001).
Patients with a CR also had better median overall survival (OS)—8.5 years and 6.3 years, respectively (P<0.0001).
The identification of early CR as a predictor of PFS and OS “underscores the importance of depth of response as we explore novel regimens for newly diagnosed MM along with MRD [minimal residual disease] endpoints,” Dr. Usmani and his colleagues wrote.
They did acknowledge, however, that the patients studied were a selected group eligible for transplant and treated on trials.
Dr. Usmani and his colleagues also performed multivariate analyses to assess clinical variables at diagnosis associated with 10-year survival as compared with 2-year death. The results indicated that patients were less likely to be alive at 10 years if they:
- Were older than 65 (odds ratio [OR]for death, 1.87, P=0.002)
- Had an IgA isotype (OR=1.53; P=0.004)
- Had an albumin level lower than 3.5 g/dL (OR=1.36; P=0.023)
- Had a beta-2 microglobulin level of at least 3.5 mg/dL (OR=1.86; P<0.001)
- Had a serum creatinine level of at least 2 mg/dL (OR=1.77; P=0.005)
- Had a hemoglobin level below 10 g/dL (OR=1.55; P=0.003)
- Had a platelet count below 150,000/μL (OR=2.26; P<0.001).
Cytogenetic abnormalities did not independently predict long-term survival, but these abnormalities were obtained only by conventional band karyotyping and were not available for some patients.
Comparison to general population
Overall, the MM patients had a relative survival of about 0.9 compared with the matched general population. Relative survival was the ratio of observed survival among MM patients to expected survival in a population with comparable characteristics, such as nationality, age, and sex.
With follow-up out to about 20 years, the cure fraction—or the proportion of patients achieving or exceeding expected survival compared with the matched general population—was 14.3%.
The researchers noted that recent therapeutic advances “have re-ignited the debate on possible functional curability of a subset of MM patients. [T]here are perhaps more effective drugs and drug classes in the clinician’s armamentarium than [were] available for MM patients being treated in the 1990s or even early 2000s.”
“This may mean that the depth of response after induction therapy may continue to improve over time, potentially further improving the PFS/OS of [the] biologic subset who previously achieved [a partial response] yet had good long-term survival.”
Dr. Usmani reported relationships with AbbVie, Amgen, BMS, Celgene, Janssen, Takeda, Sanofi, SkylineDx, Array Biopharma, and Pharmacyclics.