Investigators in France have identified a profile that predicts longer survival for one in five patients with newly diagnosed multiple myeloma, according to a study published online April 30 in the Journal of Clinical Oncology.
The absence of three key chromosomal abnormalities in malignant plasma-cell samples, together with a low beta-2 microglobulin level, was seen in this subgroup of patients. In addition, patients younger than 55 years had longer progression-free and overall survival in a relatively young population that was limited to patients less than age 66 years.
The finding favoring younger age was unexpected and "to our knowledge, it has not been reported before," said Dr. Hervé Avet-Loiseau of the hematology laboratory, Biology Institute, University of Nantes (France), and his associates.
Whereas most prognostic studies are designed to identify myeloma patients with poorer outcomes, the researchers sought to identify patients with longer life expectancy. To that end, they updated and reanalyzed the data of patients treated in the IFM (Intergroupe Francophone du Myelome) 99-02 and 99-04 trials.
Sixty percent of the 520 patients studied did not carry any of the three high-risk genetic abnormalities. Those who also were younger than age 55 years and had beta-2 microglobulin levels less than 5.5 mg/l had an 8-year probability of survival of 75%. "This subgroup represented 20% of the entire patient population," the investigators noted.
Two of the chromosomal abnormalities – t(4;14) translocation and loss of the short arm of chromosome 17, or del(17p) – are known to be associated with a poor outcome and usually are assessed as part of risk stratification in patients with multiple myeloma. The third abnormality – a gain in chromosome 1q – has recently been recognized as a prognostic indicator but has not yet been added to the typical panel of genetic probes used to assess patient prognosis.
To determine which prognostic indicators can be used to define shorter or longer survival, rather than just "poor outcome" or "better outcome," Dr. Avet-Loiseau and his colleagues included the assessment of 1q gains along with t(4:14) translocations and deletions of 17p in this large series.
For their study, Dr. Avet-Loiseau and his associates analyzed stored bone marrow and plasma samples of 520 patients who had all received the same induction regimen of vincristine, Adriamycin, and dexamethasone followed by high-dose melphalan. All the study subjects were younger than age 66 years. Median overall survival was 7.5 years.
A total of 11% of the cohort had t(4;14) translocations, 5.4% had del(17p), and 33% had 1q gains (J. Clin. Oncol. 2012 [doi:10.1200/JCO.2011.36.5726]).
In contrast, patients who had two or more of these prognostic factors had a median overall survival of only 33 months. The findings indicate that assessment of 1q gains should be added to the panel of probes used routinely in determining prognosis in patients with multiple myeloma, the researchers said.
"The question now concerns the role of novel drugs in this prognostication," the authors wrote. None of the patients received bortezomib (Velcade) in first-line treatment, although most were given novel drugs upon progression.
As bortezomib may help to overcome the poor prognosis associated with t(4;14), long-term analysis of first-line trials are warranted, they said, noting, "However, such analyses will not be possible for 4-5 years, because the first trials testing this drug started in 2005."
Dr. Avet-Loiseau reported no financial conflicts of interest; one of his associates reported ties to Celgene and Janssen-Cilag.