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.