The cyclin-D1 proto-oncogene is an important cell regulator of G1 to S phase progression. The overexpression of cyclin-D1 has been linked to the development and progression of several malignancies. The aim of our study was to evaluate the impact of the immunohistochemical expression of cyclin-D1on the plasma cells of trephine biopsies on survival of newly-diagnosed patients with multiple myeloma (MM) who were treated with novel agents. We evaluated formalin-fixed, paraffin-embedded, bone marrow sections of 130 consecutive patients with newly-diagnosed MM (67M/63F; median age 68 years) before any kind of therapy administration. One hundred and fifteen patients had symptomatic disease that required therapy: 29 (25%) received bortezomib-based regimens and 31 (26%) received thalidomide-based regimens as first line therapy, while all patients received regimens containing bortezomib or an IMiD at some point during the course of their disease. Immunohistochemistry was performed in all trephine biopsies using monoclonal antibodies against cyclin-D1 (Cell Marque Corp., Rocklin, CA, USA), but also against CD56 (Cell Marque Corp., Rocklin, CA, USA), CD27 (Novocastra, Newcastle upon Tyne, UK), CD117 and MUM-1 (DAKO A/S, Glostrup, Denmark), as recommended by the manufacturers. A case was considered positive if there was unequivocal positive staining of at least 20% of the plasma cells for cyclin-D1, CD56 and MUM-1 and a positive staining of at least 10% of the plasma cells for CD117 and CD27. Among patients with symptomatic myeloma (N=115), positive staining for cyclin-D1 was found in 35 (30%) patients, for CD56 in 45 (39%), for CD117 in 94 (81%) and for CD27 in 72 (62%) patients. In patients with asymptomatic myeloma, positive staining for Cyclin-D1 was found only in 1 (7%) patient, for CD56 in 9 (64%), and for CD117 in 6 (43%) (p<0.01 for all comparisons compared to symptomatic patients). There were significant positive correlations between positivity for CD27 and CD56 (p<0.001), between positivity for cyclin-D1 and CD117 (p=0.045) and a negative correlation between positivity for CD117 and CD56 (p=0.001). We also observed significant correlations between CD56 positivity and ISS-1 or ISS-2 (p=0.01) and between CD117 positivity and ISS-3 disease (p=0.002). The median overall survival (OS) for patients with symptomatic MM was 57 months (range 22–120 months). In the univariate analysis, positivity for cyclin-D1 (41 vs. 62 months, p=0.03) and for CD117 (50 vs. 75 months p=0.018) were associated with inferior survival, while positivity for CD56 (47 vs. 62 months, p=0.286), MUM-1 (52.7 vs. 63.8 months, p=0.528) and CD27 (57 vs. 50 months, p=0.445) were not. Other factors associated with inferior OS, in the univariate analysis, included ISS-3 (median OS 37 months, vs. 57 months for ISS-2 and 73 months for ISS-1, p=0.005), Hb <10 g/dl (56 vs. 73 months, p=0.044), corrected serum calcium >11.5 g/dl (29 vs. 62 months, p=0.02), serum LDH above upper normal limit (31 vs. 61 months, p=0.05), serum creatinine >2 mg/dl (26 vs. 64 months, p=0.007), low platelet counts (<100,000/ml) (22 vs. 62 months, p=0.031) and age >65 years (45 months vs. not reached for younger patients, p=0.002). In the multivariate analysis, positivity for cyclin-D1 (HR: 2.6; p=0.001), ISS stage (HR: 1.8; p=0.001) and age >65 (HR 2.7, p=0.003) were independently associated with inferior survival. Immunohistochemistry for cyclin-D1 identified subgroups of patients in ISS-2 and in ISS-3 who had extremely poor outcome. Patients with cyclin-D1 positivity had a median survival of 22 months in ISS-2 (vs. 64 months for the rest of ISS-2 patients, p=0.01) and of 13 months in ISS-3 (vs. 47 months for the rest of ISS-3, p=0.012). Our findings underline that the immunohistochemical expression of cyclin-D1 in the bone marrow trephine biopsies has independent prognostic value in MM patients, even in the era of novel agents. This marker can easily be assessed in patients who undergo a trephine biopsy as part of their initial evaluation and offers significant prognostic information. Furthermore, novel agents targeting cyclin-D1 may be of therapeutic value in MM.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.