Evaluation of Gastrointestinal Complications in Patients Undergoing Auto HSCT Using Melphalan-Based Conditioning Regimen

Abstract

Objective :
The aim of this study is to study the relation ship between Gastrointestinal toxicities secondary to conditioning regimens and transplant outcomes in patients with hematological malignancies unndergoing autologus hematopoietic stem cell transplantation (HSCT) with a focus on understanding the impact of melphalan-based conditioning.
Method:
A prospective cohort study was conducted on 100 patients undergoing auto HSCT from January 2024 to January 2025 with different hematologic malignancies. Patient demographics, disease statistics, conditioning regimens, and gastrointestinal toxicity profiles were collected from electronic medical records and follow-up outpatient department (OPD) visits through non-probability convenience sampling. Gastrointestinal (GI) toxicities were categorized into diarrhea, mucositis, and nausea/vomiting, with severity graded using the Common Terminology Criteria for Adverse Events (CTCAE). Descriptive statistics summarized patient and disease characteristics along with toxicity rates. Univariate analysis was done by using the Chi-square test and independent t-test, while overall survival (OS) and disease-free survival (DFS), and their association with GI toxicities were analyzed using Kaplan-Meier and Log Rank test.
Result:
Out of the 100 patients with a mean age of 44 years undergoing auto-HSCT, 61 (61%) were male and 39% were female, 49 (49%) had Plasma cell disorders (PCD), 45 (45%) had lymphoma, and 3 (3%) had other malignancies, including AML. High-dose melphalan was the conditioning regimen for all PCD, while BEAM (BCNU-Etoposide-high-dose cytarabine and carmustine) was the most common regimen among lymphomas. The mean CD34 count was 5.2 ± 2.6 ×10^6/kg and mean MNC dose was 7.2 ± 2.9 ×10^8/kg. Mean days to neutrophil and platelet engraftment were 11.6 ± 1.7 and 15.5 ± 7.9 days, respectively. Gastrointestinal toxicity was prevalent with all conditioning regimens, with any of the gut toxicities occurring in 77% of patients, diarrhea in 82%, and mucositis in 57%. A significant correlation was identified between the severity of diarrhea and overall survival (P=0.01) and between the severity of diarrhea and weight loss (P=0.00). Vomiting was significantly associated with a patient's diagnosis, specifically lymphoma (P=0.05). The mean hospital stay from infusion was 15 days. The median overall survival (OS) was 21 months with an overall survival rate of 89%; the median disease-free survival (DFS) was 21 months with an overall disease-free survival rate of 90%; non-relapse mortality was 6%.

Conclusion:
Our study highlights a concession in melphalan-based therapy. While higher doses improve overall survival rates, they also significantly increase the risk of severe gastrointestinal toxicity (grade 3–4 mucositis). Clinicians must weigh these risks carefully when planning conditioning regimens.