Patient characteristics.
This study consisted of 54 osteosarcoma patients with complete clinical data, including 30 men and 24 women. The mean age was 28 [range, 8-93] years old, and tumors were located at the appendicular skeleton in 41 patients, axial skeleton in 10 patients, and other sites in 3 patients. All of the patients were diagnosed with primary osteosarcoma pathologically by a biopsy at our department, and 93% of the patients (50/54) received chemotherapy. All but seven patients underwent surgery. Radiotherapy, including carbon-ion radiotherapy, was performed in seven patients because of their unresectable lesions. The mean follow-up period was 72 (Interquartile range [IQR]: 48-147) months. The number of patients suffering from distant metastasis during the follow-up periods was 27 (50%), including 6 (11%) at the first visit.
The optimal cut off value for inflammatory-based scores.
We compared the significance of CRP, LMR, NLR, PLR, NC, LC, and MC for discriminating between metastasis and non-metastasis using ROC curves. The optimal cut-off points of CRP, LMR, NLR, PLR, NC, LC, and MC were 0.60, 5.68, 2.82, 116, 4087, 1973, and 360, respectively. The areas under the curve (AUCs) of CRP, LMR, NLR, PLR, NC, LC, and MC were 0.59, 0.58, 0.52, 0.69, 0.66, 0.59, and 0.62, respectively (Table 1). Of the 54 patients, 36 had a GPS of 0, while 17 and 1 showed a GPS of 1 and 2, respectively. The patient numbers with an NPS of 0, 1, and 2 were 49, 3, and 2, respectively. The patient numbers in the high groups of CRP, NLR, MNR, LMR, and PLR were 13, 15, 19, and 25, respectively, and the patient numbers in the high groups of NC, LC, and MC were 23, 25, and 23, respectively.
Survival analysis and multivariate analysis for prognostic factors of metastasis.
High values of CRP, PLR, MNR, NPS, and a low NC were significantly associated with distant metastasis in the univariate analysis. Among them, a multivariate Cox regression analysis revealed that a high level of CRP (>0.6mg/dL) (hazard ratio [HR]=9.7, 95% confidence interval [CI]=3.0-30.9; p=0.0001) and low NC (<4087/µL)) (HR=0.13, 95%CI=0.04-0.42 ; p=0.0008) were risk factors significantly associated with metastasis of osteosarcoma patients (Table 2). The survival curve revealed that the 5-year distant metastasis-free survival of patients with a high level of CRP was 29%, while the 5-year distant metastasis-free survival of patients with a low level of CRP was 61% (p=0.02) (Fig.1a). In addition, the 5-year distant metastasis-free survival of patients with a low NC was 42%, while the 5-year distant metastasis-free survival of patients with a high NC was 73% (p=0.04) (Fig.1b). Furthermore, among patients who had both a low level of CRP and a high NC (n=13), the 5-year distant metastasis-free survival was 100% until metastasis of only one patient in the group was first detected at 114 months (p=0.004) (Fig.1c).
Patients characteristics in each group according to the values of CRP and NC
The patient characteristics in each group according to the values of CRP and NC are shown in Table 3. There were no significant differences in the groups with higher and lower CRP (Table 3a). In the group with a low NC, radiation therapy including carbon ion radiotherapy, was performed more often than in the group with a high NC, instead of surgery (Table 3b). However, the rate of chemotherapy did not differ significantly between the groups with low and high NC.