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We analyzed 44 patients with newly diagnosed systemic light-chain amyloidosis (AL) and del 17p, a rare finding in AL. Predictors of overall and progression-free survival were cardiac involvement at diagnosis and hematologic response to therapy, respectively. Median survivals of patients with > 50% and ≤ 50% del 17p plasma cells were 28 and 52 months (P = .08). Introduction: Deletion 17p (del 17p) portends a poor prognosis in myeloma, but its significance in light-chain amyloidosis is unknown. Patients and Methods: We identified patients with light-chain amyloidosis and del 17p at diagnosis, and analyzed presenting characteristics, treatments, and clinical outcomes. All had baseline biopsy results showing amyloid and serologic and marrow studies, including standard fluorescence in-situ hybridization determinations of del 17p using commercial probes. Consensus criteria for hematologic and organ involvement, progression, and response were used. Kaplan-Meier (log rank) analyses and Cox regression analysis of baseline variables were used to identify predictors of overall and progression-free survival (PFS). Six-month landmark analyses were performed to assess the impact of treatment-related variables. Results: We identified 44 patients from 7 countries with median marrow and del 17p plasma cells of 22% (range, 3%–100%) and 30% (2%–93%). Ninety-five percent had cardiac involvement, including 44% stage III. Two-thirds of the patients initially received bortezomib-based therapy. Forty-nine percent of patients experienced complete response or very good partial response, with median time to best response of 4 months (range, 1–28 months). Median overall survival and PFS were 49 and 32 months. Cardiac stage and hematologic response were the key predictors of outcomes. Patients with > 50% and ≤ 50% del 17p in clonal plasma cells had median survivals of 28 and 52 months, respectively (P = .08). In landmark analyses, only hematologic response predicted both overall survival and PFS. Conclusion: Cardiac stage, hematologic response, and del 17p percentage impact outcomes in these cases. Emphasis should be placed on optimizing supportive care and achieving a deep hematologic response.

Within a prospective protocol, the incidence and impact of achievement of molecular remission (mCR) and high-risk cytogenetics was investigated in 73 patients with multiple myeloma (MM) after autologous (auto)–allogeneic (allo) tandem stem cell transplantation (SCT). After induction chemotherapy, patients received melphalan 200 mg/m2 before undergoing auto-SCT, followed 3 months later by melphalan 140 mg/m2 and fludarabine 180 mg/m2 before allo-SCT. Sixteen patients had high-risk cytogenetic features, defined by positive FISH for del(17p13) and/or t(4;14). Overall, 66% of the patients achieved CR or near-CR, and 41% achieved mCR, which was sustained negative (at least 4 consecutive samples negative) in 15 patients (21%), with no significant difference in incidence between the patients with high-risk cytogenetics and others (P = .70). After a median follow-up of 6 years, overall 5-year progression-free survival was 29%, with no significant difference between del 17p13/t(4;14)-harboring patients and others (24% versus 30%; P = .70). The 5-year progression-free survival differed substantially according to the achieved remission: 17% for partial remission, 41% for CR, 57% for mCR, and 85% for sustained mCR. These results suggest that auto–allo tandem SCT may overcome the negative prognostic effect of del(17p13) and/or t(4;14) and that achievement of molecular remission resulted in long-term freedom from disease.