Variables Associated With the Risk of Severe Mucositis During Autologous Transplantation in Multiple Myeloma Patients

Autologous stem cell transplantation (ASCT) with melphalan 200 mg/m² remains a standard treatment for multiple myeloma (MM). We analyzed the incidence and risk factors associated with the development of mucositis in 1,268 MM patients who underwent ASCT between 2017 and 2022 across 13 national centers.

Median age was 60 years (24-77), and 44% were female. Induction therapy included chemotherapy or cyclophosphamide (principally VCD) in 32%, and 21% had creatinine > 1 mg/dL. Melphalan was administered in a single day (Mel1) in 52% and over 2 days (Mel2) in 48%. Prophylaxis measures included cryotherapy (75%), G-CSF (78%) and antibiotics (37%). Mucositis occurred in 84% of patients, with 26% experiencing severe cases (WHO grade III-IV), which were significantly associated with increased intravenous opioids use, parenteral nutrition, and febrile episodes. Severe mucositis was more common in women (32% vs. 22%), patients over 60 (53% vs. 60%), chemotherapy induction (37% vs. 20%), creatinine > 1 mg/dL (34% vs. 24%), those not receiving G-CSF (35% vs. 24%) or antibiotic (36% vs. 16%). It was also more common with single day melphalan (29% vs. 24%). In the multivariable analysis, all factors except chemotherapy-based induction were identified as independent predictors of severe mucositis.

In our population, an increased incidence of severe mucositis was observed in nonmodifiable factors such as sex and renal function. However, the implementation of modifiable factors, including the use of prophylactic G-CSF or antibiotics and administering melphalan over 2 days could diminish the severity of this complication.