[Analysis of influencing factors of recurrence after en bloc spondylectomy of spinal tumors].

<b>Objectives:</b> To investigate the survival and tumor recurrence after en bloc spondylectomy of spinal tumor and analyze the risk factors of postoperative tumor recurrence. <b>Methods:</b> This is a retrospective case series study. Data of 101 patients undergoing en bloc spondylectomy of spinal tumors in the Musculoskeletal Tumor Center, Peking University People's Hospital from December 2006 to June 2022 were analyzed. There were 58 males and 43 females, aged (38.2±15.8) years (range: 10 to 79 years) at the time of surgery; the follow-up time was(44.0±36.0) months (range: 12 to 171 months).Among them, there were 25 relapsed patients, with 7 females and 18 males; aged (34.8±16.3) years (range: 12 to 66 years) at the time of surgery. The types of tumors included 5 giant cell tumors of bone, 6 osteosarcomas, 1 chordoma, 5 chondrosarcomas, 1 undifferentiated sarcoma, 1 fibrosarcoma, 2 Ewing sarcomas, 3 metastases and 1 malignant giant cell tumor of bone. Survival analysis of overall and relapsed patients were performed using the Kaplan-Meier curves. A segmented regression model was used to fit the sequence of recurrence rate changes over time since admission and identify change points for further analysis on risk factors. Univariate and multivariate Logistic regression analysis were performed to assess risk factors associated with recurrence rate; results from multivariate regression analysis were presented using a forest plot. <b>Results:</b> The tumor recurrence rate after en bloc spondylectomy was 24.8% (25/101).The overall median recurrence-free survival after en bloc spondylectomy was 161 months (95%<i>CI</i>: 92 months to NA).The median recurrence-free survival of recurrent patients was 13 months (95%<i>CI</i>: 12 to 27 months).Regarding the classification based on tumor malignancy, and relapse-free survival of metastatic tumors was significantly shorter (<i>P</i>=0.007); and among the surgical margin groups, relapse-free survival of R0 group was significantly better than the R1 and R2 groups (<i>P</i><0.01). According to the segmented regression model, the tumor recurrence rate for en bloc spondylectomy showed a significant downward trend over time, with relatively higher recurrence rates before 2009 and a relatively stable trend after 2014. The results of univariate analysis showed that surgical margin and time of admission were the influencing factors of patient recurrence. The results of multivariate analysis showed that the R1 resection(<i>OR</i>=13.453,95%<i>CI</i>:2.897 to 97.941,<i>P</i>=0.002) and R2 resection(<i>OR</i>=11.379,95%<i>CI</i>:2.658 to 79.429,<i>P</i>=0.003) were independent influencing factor affecting patient recurrence. <b>Conclusions:</b> The overall tumor recurrence rate after en bloc spondylectomy was high. The surgical margin of tumor resection is an independent risk factor affecting tumor recurrence. Specifically, R2 and R1 resections significantly increase the risk of tumor recurrence.