MATERIAL AND METHODS
Design and study population
A retrospective observational study was performed including patients
diagnosed with hepatoblastoma and treated in our center between 2006 and
2021. Patients who met any of the following criteria were excluded:
- Patients younger than 12 months of age at diagnosis, since the
reference values established for PMA are only validated in patients
older than 12 months.
- Patients with unavailable radiological examinations (CT and/or MR)
performed at diagnosis.
- Patients whose treatment or follow-up was carried out in another
center.
The selected patients were divided according to the presence or absence
of sarcopenia at diagnosis into two groups: those with sarcopenia (SP
group) and those without sarcopenia (NSP group).
As the retrospective study described is within the bounds of regular
clinical practice and written informed consent to participate in this
study was provided by the participants’ legal guardian, ethical review
and approval was not required in accordance with the local legislation
and national guidelines.
Study variables:
All variables of interest for this study were obtained and recorded
anonymously from the patient’s clinical reports, including:
- Demographic data : sex, age, weight and body mass index (BMI) at
diagnosis. The BMI z-score values were calculated using the
anthropometric tables developed by the World Health Organization
(WHO)15.
- Tumor characteristics : PRETEXT classification, tumor volume
(calculated in cm3 from the measurements of the
radiological examinations), patient risk group (according to the
criteria established by the Children’s Hepatic tumors International
Collaboration)4, laboratory data (α-fetoprotein,
serum albumin and serum total proteins), surgical treatment (liver
resection or liver transplant) and extension of the disease at
diagnosis.
- Sarcopenia status : in order to determine the presence of
sarcopenia at diagnosis, the radiological examinations performed at
the time disease diagnosis before starting any medical or surgical
treatment (CT or MR) were reviewed. The total PMA (tPMA) was
calculated by the sum of the left and right PMA
(mm2). Each PMA was measured individually in the
axial plane, at L4-L5 intervertebral disc space (Figure 1). The
analysis was performed by a single pediatric radiologist of our
center, blinded for the final clinical outcome of the patients. The
tPMA z-score values was calculated using reference tables according to
age and gender14. The presence of sarcopenia was
defined as those z-score values <-2.
- Surgical outcomes : the presence of postoperative complications
(biliary leakage, bleeding, cholestasis, etc.), infectious
complications, length of Intensive Care Unit (ICU) stay after surgery
and length of overall hospital stay (from surgery to discharge).
Postoperative complications were classified according to the
Clavien-Dindo classification16. Only postoperative
complications grade III or IV were taken into account, due to their
clinical significance.
- Survival outcomes : events (tumor relapse and/or mortality) were
recorded and EFS and OS were analyzed.
Statistical analysis:
The variables studied in this work were analyzed using the IBM SPSS
Statistic 22.0 statistical package. For descriptive analysis,
quantitative variables were expressed as mean ± standard deviation (SD)
or median and interquartile range (IQR), while qualitative variables
were expressed as percentages.
To compare qualitative variables, the Chi-square test or Fisher’s Exact
Test was used as appropriate. To compare quantitative variables, the
Student’s t-test (for normal variables) or the Mann-Whitney U test
(variables that did not follow a normal distribution) were used. The
Odds ratio (OR) was calculated using the Baptista-Pike method. The study
of correlation between quantitative variables was performed using
Pearson’s or Spearman’s correlation test as appropriate, expressing the
strength and direction of the association with the r statistic (p
value). Survival curves were obtained by the Kapplan-Meyer method, using
the Log-rank test for comparisons.
All differences with a p-value <0.05 were considered
statistically significant. All confidence intervals (CI) were calculated
at 95%.