Methods
This retrospective cohort study evaluated pediatrics patients diagnosed
with HL, ages 4-20 years old at diagnosis, between 1999 and 2018 at
Children’s Hospital Los Angeles (CHLA). Patients were identified by
reviewing an already-existing database of patients maintained for the
purposes of providing direct patient care. All patients who received
ABVD and/or ABVE-PC as initial treatment for newly diagnosed HL were
included. Patients were excluded due to either receiving a different
therapy (e.g. bleomycin, etoposide, doxorubicin,
cyclophosphamide, vincristine, procarbazine and prednisone {BEACOPP}),
incomplete therapy, receiving therapy at an outside institution of CHLA
with incomplete data including pathology reports, treatment
documentation and disease response evaluations.
Demographic information collected included: age at diagnosis as well as
self-reported gender, race, and ethnicity. Prognostic variables
abstracted from the medical record included Ann Arbor staging, presence
of B-symptoms (unexplained weight loss > 10% in the
preceding 6 months, unexplained recurrent fever ≥ 38°C in the preceding
month or recurrent drenching sweats in the preceding month), presence of
splenic involvement, presence of extra-nodal disease, erythrocyte
sedimentation rate at diagnosis, peripheral blood leukocyte count at
diagnosis, and hemoglobin concentration at diagnosis. All chemotherapy
regimens, including changes and deviations, were recorded. Results of
positron emission tomography/computed tomography (PET/CT) were recorded
where available. Total anthracycline doses were recorded in
doxorubicin-equivalent units and reported as mg/m2.
Echocardiogram and pulmonary function testing results were recorded
where available. OS was defined as the time from diagnosis to death of
any cause. EFS was defined as the time from diagnosis to death,
relapse/progression of disease, or diagnosis of a secondary malignancy.
Descriptive analyses were performed using the Student’s t-test or
Fisher’s exact test for continuous or dichotomous variables,
respectively. Survival analysis was performed using the Kaplan-Meier
life table method. All analyses followed an intention-to-treat
principle, guided by the initial therapy chosen. Late effects were
analyzed and including secondary malignancy, pulmonary toxicity and
cardiomyopathy determined by shortening fraction <29%. We
assessed treatment response from the available radiology reports, which
included CT and PET/CT. Disease response was assessed by change in
maximum SUV, change in the size of lymph nodes, and, if available, the
Deauville score. All analyses were carried out on the R Project for
Statistical Computing version 3.
All study protocols were carried out under supervision of the IRB and in
compliance with the Declaration of Helsinki.