Demographic and clinicopathologic characteristicsof patients with chordoma
According to the inclusion and exclusion criteria in Figure 1, our study included a total of 1,080 eligible patients with chordoma from 1975 to 2017. The number of married, divorced/separated, widowed and single group were 700 (64.8%), 88 (8.1%), 78 (7.2%) and 214 (19.8%), respectively. Table 1 shows the clinical characteristics and demographic of all adult patients with chordoma. The chi-square test showed that there were significant differences in the five variables of diagnosis year (p=0.014), age at diagnosis (p<0.001), sex (p<0.001), primary site (p=0.019) and surgery (p<0.001). With the increase in years, the proportion of patients with chordoma also increased. In the whole cohort, the majority of patients were male (59.9%), the primary site was bones of the skull and face and associated joints (40.4%), and localized stage predominated (40.9%). In addition, the percentages of older (>60 years, 94.9%), female (73.1%) and non-surgery (37.2%) patients in the widowed group were also the highest.
Survival of patients with chordoma
By analysing the Kaplan-Meier curve with a log-rank test, we found that age at diagnosis (p<0.001), marital status (p<0.001), primary site (p<0.001), disease stage (p<0.001), tumour size (p<0.001), histological type (p=0.002), surgery (p<0.001) and chemotherapy (p=0.001) were associated with OS (Table 2). The 5-year OS and 10-year OS of married, divorced/separated, widowed and single patients were 73.7% and 51.5%, 69.5% and 42.8%, 45.2% and 12.5%, and 75.6% and 57.0%, respectively, and the median survival times of married, divorced/separated, widowed and single patients were 125.0 months, 103.0 months, 56.0 months and 157.0 months, respectively (Figure 2). Widowed patients had the lowest 5-year OS, 10-year OS and median overall survival time, while single patients had the highest 5-year OS, 10-year OS and median overall survival time. After stratifying the primary site and disease stage, we still observed similar results (Table 3 and Figure 3).
Identification of prognostic factors of the OS of patients with chordoma
Univariate and multivariate Cox regression were used to analyse the prognostic factors associated with the OS of patients with chordoma (Table 4). Univariate Cox regression analysis showed that age at diagnosis, marital status, primary site, disease stage, tumour size, histological type, surgery and chemotherapy were factors (all p<0.05) related to OS in patients with chordoma (Figure 4). Moreover, after all factors were included in the multivariate analysis, primary site, histological type, radiotherapy and chemotherapy were not independent risk factors for patients with chordoma (Figure 5). In addition, multivariate analysis showed that widowed patients had the worst OS (HR: 1.71; 95% CI: 1.25–2.33, p < 0.001) compared with married patients.
In the stratification of primary site and disease stages (Table 5), univariate analysis showed that marital status was a risk factor for OS in the primary site of “Bones of the skull and face and associated joints”, “Vertebral column”, and “Localized”, “Regional”, and “Distant” disease stages. In addition, multivariate analysis showed that marital status was an independent risk factor for the primary site of “Bones of skull and face and associated joints” and “Vertebral column”. Moreover, although marital status was not an independent risk factor for the prognosis of patients with chordoma at the disease stages of “Localized”, “Regional”, and “Distant”, widowed patients were at higher risk of survival compared with married, divorced/separated or single patients.