3.1 | Osteogenic sarcoma
3.1.1 | Demographic, diagnosis,
disease, and treatment variables
As demonstrated in Table 1 , patients treated at a pediatric
center were statistically significantly younger (15.57 ± 0.85 years vs
17.99 ± 1.50 years, p<0.001) and more likely to have
metastases than those treated at an adult center (36.2% vs 16.7%,
p=0.01). Clinical trial enrollment was significantly more common in
pediatric centers compared to adult centers (55% versus 1%,
p<0.001). The distribution of sex, DIL, socioeconomic
variables, and bone primary site did not differ between pediatric and
adult centers.
There was no difference in the type of local therapy or time to local
therapy in pediatric versus adult centers.
The median cumulative doses of methotrexate, doxorubicin, and the CED
were all significantly and substantially higher in pediatric centers
than adult centers.
3.1.2 | Survival outcomes
The median follow-up time was 8.1
years (Interquartile range [IQR] 2.0 - 17.1 years; range 0.0 -26.7
years). Among patients with
localized disease, EFS was the longest in the patients aged 18 or older
who received care in adult centers followed by pediatric-center patients
and adult-center patients younger than 18 years, respectively (5-year
EFS ± SE: 66% ± 7% vs 53% ± 9% vs 43% ± 9%; p=0.04) (Fig.
1A and 1B ). Females had significantly better survival outcome than
males (5-year EFS ± SE: 76% ± 7%
vs 46% ± 6; p=0.006).Among those with metastatic
disease, higher 5-year EFS rates were observed in the patients who
received higher doses of doxorubicin (36% ± 15% vs 6% ± 6%;
p=0.004), methotrexate (44% ± 17% vs 5% ± 5%; p=0.001), and
cisplatin (31% ± 13% vs 7% ± 6%; p=0.03). None of tumor primary
site, income quintile, rurality, immigration status, DIL, clinical trial
enrollment, or time to local therapy were associated with EFS in
localized or metastatic cohorts.
Table 2 shows the results of univariate and multivariable Cox
proportional hazards survival analyses in both localized and metastatic
OGS cohorts. Multivariable analysis in the localized cohort revealed
only the statistically significant association of sex with EFS; (i.e.,
males had inferior EFS compared to females). In the metastatic cohort,
only the association of higher cumulative doses of
methotrexate, doxorubicin and
cisplatin with better EFS were significant in multivariable analyses.