A small study has identified several risk factors for developing second primary malignancy (SPM) in patients with either transplant-eligible or -ineligible multiple myeloma, including older age at diagnosis and a history of certain treatments for their disease.1
Overall though, researchers led by Satoshi Yamasaki, MD, PhD, of the National Hospital Organization Kyushu Medical Center, Fukuoka, Japan, concluded that the risk for SPM was small in their study and that the survival benefit of receiving these treatments outweighed the increased risk for SPMs.
“Patients with multiple myeloma are older, with a median age at diagnosis of about 70, which increases the risk of [a} second primary [malignancy],” explained Henry Chi Hang Fung, MD, vice chair, department of hematology/oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania, who was not involved in the study. “In addition, myeloma patients are immunocompromised and their treatment with Revlimid, radiation, chemotherapy, and autologous stem cell transplant all increase [the] risk of second primary.”
To evaluate the incidence and risk factors for SPM, Dr Yamasaki and colleagues looked at data from 211 transplant-eligible and 280 transplant-ineligible patients with myeloma. They identified 17 transplant-eligible and 12 transplant-ineligible patients with SPM.
Among these patients were 7 transplant-eligible and 4 transplant-ineligible patients with hematologic malignancies and 10 transplant-eligible and eight transplant-ineligible patients with nonhematologic cancers.
Median follow-up was at least 4 years. Development of SPM was rare, with a cumulative incidence at 5 years of 5.57% in transplant-eligible patients and 7.05% in transplant-ineligible patients.
Using multivariable analysis, the researchers found that a history of high-dose cyclophosphamide for peripheral blood stem cell harvest was significantly associated with SPM in transplant-eligible patients (P < .001). Among transplant-ineligible patients, aged older than 65, or a history of adriamycin, lenalidomide, or thalidomide was independently associated with risk for SPMs (P < .001).