Abstract:
PURPOSE : Response assessment of classical Hodgkin lymphoma (cHL) with positron
emission tomography-computerized tomography (PET-CT) is standard of care
in well-resourced settings but unavailable in most African countries. We aimed
to investigate correlations between changes in PET-CT findings at interim
analysis with changes in blood test results in pediatric patients with cHL in 17
South African centers.
METHODS : Changes in ferritin, lactate dehydrogenase (LDH), erythrocyte sedimentation
rate (ESR), albumin, total white cell count (TWC), absolute lymphocyte count
(ALC), and absolute eosinophil count were compared with PET-CT Deauville
scores (DS) after two cycles of doxorubicin, bleomycin, vinblastine, and
dacarbazine in 84 pediatric patients with cHL. DS 1-3 denoted rapid early response
(RER) while DS 4-5 denoted slow early response (SER). Missing values
were imputed using the k-nearest neighbor algorithm. Baseline and follow-up
blood test values were combined into a single difference variable. Data were split
into training and testing sets for analysis using Python scikit-learn 1.2.2 with
logistic regression, random forests, na¨ıve Bayes, and support vector machine
classifiers.
RESULTS : Random forest analysis achieved the best validated test accuracy of 73% when
predicting RER or SER from blood samples. When applied to the full data set, the
optimal model had a predictive accuracy of 80% and a receiver operating
characteristic AUC of 89%. The most predictive variable was the differences in
ALC, contributing 21% to the model. Differences in ferritin, LDH, and TWC
contributed 15%-16%. Differences in ESR, hemoglobin, and albumin contributed 11%-12%.
CONCLUSION : Changes in low-cost, widely available blood tests may predict chemosensitivity
for pediatric cHL without access to PET-CT, identifying patients who may not
require radiotherapy. Changes in these nonspecific blood tests should be
assessed in combination with clinical findings and available imaging to avoid
undertreatment.
Description:
PRIOR PRESENTATION :
Presented at 55th Annual Conference of the International Society of
Pediatric Oncology, Ottawa, Canada, October 11-14, 2023.
DATA SHARING STATEMENT :
The dataset for this study is available on request.
