The predictive value of systemic immune-inflammation index for bone metastasis in patients newly diagnosed with prostate cancer / 中华泌尿外科杂志

ABSTRACT

Objective:To explore the predictive value of the systemic immune inflammation index (SII) for the risk of bone metastases in patients with newly diagnosed prostate cancer (PCa).Methods:From Jun. 2012 to Jul. 2019, the clinical features of 308 patients were retrospectively analyzed. For the baseline clinical data of the patients with newly diagnosed PCa, the median age was 71(65-76) years, there were 59(19.2%) patients with a positive digital rectal examination (DRE). In addition, the median serum total prostate-specific antigen (tPSA), prostate volume (PV) and prostate-specific antigen density(PSAD)were 60.55(23.55-100.00) ng/ml, 39.35(28.29-56.66)ml and 1.27(0.58-2.52)ng/(ml·cm 3), respectively. There were 33(10.7%)patients with prostate biopsy Gleason score≤6, 115(37.3%)patients with a Gleason score=7 and 160(52.0%)patients with a Gleason score≥8. The T clinical stage also obtained, including 21(6.8%)diagnosed as T 1 stage, 87(28.2%)T 2 stage, 65(21.1%)T 3stage, 135(43.9%)T 4 stage. SII was calculated by the formula platelet×neutrophil/lymphocyte, and the median(interquartile range)of SII was 458.60(300.42-727.11)/L. According to the results of bone scanning, the patients were divided into bone metastasis(146, 47.4%)and a non-bone metastasis groups(162, 52.6%). The differences in the baseline clinical characteristics between the two groups were analyzed. The risk factors of bone metastasis were analyzed by univariate and multivariate logistic regression analysis. The diagnostic efficiency of the risk factors were evaluated by receiver operating characteristic(ROC)curve. Results:The median(interquartile range)of SII was 564.78/L(333.85-961.93/L)in patients with bone metastasis which were higher than those without bone metastasis 413.01(267.63-601.79)/L( P<0.001). The median(interquartile range)of tPSA were 97.79(48.20-119.10)ng/ml in bone metastasis group and 32.56(17.89-72.70)ng/ml in non-bone metastasis group ( P<0.001). The median(interquartile range)of PSAD were 1.91(0.97-3.55)ng/(ml·cm 3)and 0.90(0.45-1.77)ng/(ml·cm 3)in these two groups( P<0.001), respectively. In bone metastasis group, there were 132(90.4%)patients with a positive DRE, yet there were only 117(72.2%) patients with a positive DRE in the other group ( P<0.001). There were 7(4.8%)patients with prostate biopsy Gleason score≤6, 50(34.2%)patients with a Gleason score=7 and 89(61.0%)patients with a Gleason score≥8 in bone metastasis group. There were 26(16.1%)patients with prostate biopsy Gleason score≤6, 65(40.1%)patients with a Gleason score=7 and 71(43.8%)patients with a Gleason score≥8 in non-bone metastasis group ( P<0.001). There were statistically significant difference between the two groups in T clinical stage( P<0.001). In bone metastasis group, there were 2(1.4%)T 1 stage, and 19(13.0%)T 2 stage, 25(17.1%)T 3stage, and 100(68.5%)T 4 stage. Comparatively, there were 19(11.7%)T 1 stage, 68(42.0%)T 2 stage, 40(24.7%)T 3stage, and 35(21.6%)T 4 stage in the other group. There were no statistically significant difference between the two groups in term of age( P=0.057) and TPV( P=0.222). Univariate and multivariate logistic regression analysis showed that tPSA( P=0.003), SII( P<0.001), T clinical stage( P<0.001)could be regarded as independent risk factors of bone metastasis of PCa. Area under the curve of SII+ tPSA was 0.770, which was higher than SII(0.653)or tPSA(0.729) alone( P<0.05). When the cut-off value was 727.72/L, the sensitivity and specificity of the diagnosis of SII alone were 38.4% and 87.7%. The sensitivity and specificity of tPSA alone were 67.1%and 75.9% when the cut-off value was 73.02ng/ml. The sensitivity was 72.6% and the specificity was 71.6% when SII and tPSA was combined. Conclusions:SII is an independent predictor of bone metastasis of newly diagnosed with PCa. , and the patients were at high risk when SII exceeded 727.72/L. The combination of SII and tPSA can improve its predictive validity for the risk of bone metastasis.