Clinical features and treatment outcome of elderly multiple myeloma patients with impaired renal function

Abstract Background Renal impairment (RI) is a most common complication of multiple myeloma (MM), which is associated with an increased risk of early death and worse survival. Methods We retrospectively analyzed clinical features and outcomes of 77 MM patients over 70 years old and compared the differences between with and without RI groups. Results The percentage of elder MM patients with RI was 61%. Hemoglobin level was a protective factor (OR = 0.954, P = 0.033), while creatinine and hypertension were hazards (OR = 1.288, P < 0.001 and OR = 30.12, P = 0.008). And the percentages of patients with mild‐to‐moderate RI and moderate‐to‐severe RI were 40.4% and 59.6%. Complete remission (CR) rate was higher in patients treated with bortezomib (33.3%) than those with non‐bortezomib treatment (3.33%) (P = 0.007). Meanwhile, CRrenal was higher in patients with bortezomib (58.3%) than non‐bortezomib treatment (22.2%) (P = 0.025). The median OS of the patients with RI treated with bortezomib was longer than those with non‐bortezomib regimens (15.0 vs 6.0 months, P = 0.001). The same result was observed in the patients with moderate‐to‐severe RI (13.0 vs 6.0 months, P = 0.007). The median OS of the patients with RI receiving the bortezomib regimens (15 months) was longer than those with non‐bortezomib regimens (6.0 months) (P = 0.001). Conclusion Hemoglobin is a protective factor in elder patients with RI, while creatinine and hypertension were hazards. The median OS of elderly patients with RI was worse, and bortezomib can improve the CR rate in these patients.

Health Organization (WHO) defines "elderly" as older than the age of 65 years, the aging is a evidently heterogeneous phenomenon. 3 The incidence of MM increases steadily with advanced age. 4 Meanwhile, the incidence of various complications in elderly MM patients also is increased. As we all know, renal impairment (RI) is a most common complication of MM that can be present at diagnosis or emerge during therapy. 5,6 RI can be elicited by various factors, such as infections, non-steroidal anti-inflammatory drugs, nephrotoxic antibiotics, iodinated contrast media, hypercalcemia, tumor lysis syndrome, myeloma cell infiltration of the kidney, and renal vein or artery thrombosis, and, frequently, by clonotypic light chains. 7 The presence of RI places the patients at TA B L E 1 The clinical and laboratory characteristics between the patients without RI and with RI (n = 77) higher risk for complications after anti-myeloma treatment and is associated with an increased risk of early death. 8 The MM patients with advanced age are usually excluded from clinical trials due to poor performance status (PS), various complications, and socioeconomic reasons. 9 Therefore, limited scientific data are available regarding the clinical characteristics and treatment outcomes in this group of patients. 10,11 13 ( Table 2 shows the clinical and laboratory characteristics between the patients with mild-to-moderate RI and moderate-to-severe RI, which were 40.4%

| Baseline characteristics
and 59.6%, respectively. There were significant differences in diabetes, BUN, creatinine, GFR, and β2-microglobulin between the two groups.

| Treatment outcome
Fifty-seven patients received chemotherapy, including TD, VAD, and MP (non-bortezomib group, n = 30) or VD, VCD, and VTD (bortezomib group, n = 27, 2 patients had no therapeutic evaluation). Table 3 shows the treatment outcomes of the two groups. CR rate was higher in bortezomib group (non-bortezomib and bortezomib; 3.33% and 33.3%, respectively, P = 0.007). Furthermore, there were 21 patients whose GFR is <50mL/min received chemotherapy. We found that CRrenal was higher in bortezomib group (non-bortezomib and bortezomib; 22.2% and 58.3%, respectively, P = 0.025) ( Table 4). of the group with mild-to-moderate RI and moderate-to-severe RI was 10.0 and 9.0 months, and the median OS of these two groups was 12.0 and 9.0 months. Log-rank analysis indicated that there was no significant difference in PFS and OS between these two groups, while we found PFS and OS of the group with mild-to-moderate RI were longer than those with moderate-to-severe RI. Furthermore, the median OS of the group with RI and with moderate-to-severe RI treating with the bortezomib-containing regimens was longer than those with non-bortezomib-containing regimens, 15.0 vs 6.0 months and 13.0 vs 6.0 months, respectively, P = 0.001 and P = 0.007) (Figure 2). subgroups. 20 The improvement in RI to a near-normal range (CrCL ≥60 mL/min) observed in the majority of MM patients in the current study suggests that bortezomib may be a particularly useful therapy in this setting. In our study, CR rate was higher in patients treated with bortezomib. As the similar result, CRrenal was higher in bortezomib group. Among the patients ≥70 years old, patients without RI showed significantly longer PFS and OS compared to those with RI.

| Progression-free and overall survival
The OS of patients during the treatment of bortezomib-containing regimens in mild-to-moderate RI and moderate-to-severe RI group was longer than those without RI.
In conclusion, we showed that elderly MM patients with RI, using first line of bortezomib-containing regimens treatment, can achieve higher CR and CRrenal rates, and prolong their survival.