The incidence of severe oral mucositis in patients undergoing different conditioning regimens in haematopoietic stem cell transplantation.

PURPOSE: Oral mucositis is a common complication during haematopoietic stem cell transplantation (HSCT). This study aimed to assess the incidence of severe mucositis in patients undergoing different HSCT regimens. METHODS: This single-centre retrospective study reviewed daily oral assessment for 467 consecutive patients who underwent different transplant regimens for matched unrelated or related allogeneic HSCT with post-transplant methotrexate, haploidentical or mismatched HSCT with post-transplant cyclophosphamide (PTCy), or autologous HSCT. Oral care and cryotherapy with melphalan were used. Patient demographic data, oral mucositis WHO grade, use of total parenteral nutrition (TPN) and patient-controlled analgesia (PCA) were collected. RESULTS: Grade 3-4 oral mucositis was common in myeloablative total body irradiation (TBI)-based regimens cyclophosphamide/ TBI (CyTBI) (71%) and fludarabine/ TBI (FluTBI) with PTCy (46%), as well as reduced-intensity fludarabine/melphalan (FluMel) (43%) and carmustine/etoposide/cytarabine/melphalan (BEAM) autologous HSCT (41%). In contrast, grade 3-4 oral mucositis was less common in reduced-intensity haploidentical regimen melphalan/fludarabine/TBI with PTCy (19%), all non-myeloablative regimens (0-9%) and high-dose melphalan autologous HSCT (26%). TPN and PCA use were correlated to oral mucositis severity. CONCLUSIONS: Severe oral mucositis was associated with myeloablative TBI, methotrexate and melphalan in combination with methotrexate and in BEAM. Use of PTCy was preferable over methotrexate to prevent oral mucositis.