, Chun-Yu Wu2,3,4
, Yen-Heng Lin2,5
, Yu-Cheng Huang2,5
, Wen-Chi Yang2,6
, Tom Wei-Wu Chen2,7,8
, Wei-Li Ma2,7,8
, Wei-Hsin Lin2,9
, Feng-Ming Hsu2,6,8
, Furen Xiao2,10
, Shih-Hung Yang2,10
, Dar-Ming Lai2,10
, Chang-Mu Chen2,10
, Shin-Yi Chao10
, Fon-Yih Tsuang2,10
1Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu County, Taiwan
2Spine Tumor Center, National Taiwan University Hospital, Taipei City, Taiwan
3Department of Anesthesiology, National Taiwan University Hospital, Taipei City, Taiwan
4Department of Anesthesiology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu County, Taiwan
5Department of Medical Imaging, National Taiwan University Hospital, Taipei City, Taiwan
6Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei City, Taiwan
7Department of Oncology, National Taiwan University Hospital, Taipei City, Taiwan
8Graduate Institute of Oncology, National Taiwan University College of Medicine, Taipei City, Taiwan
9Department of Orthopaedic Surgery, National Taiwan University Hospital, Taipei City, Taiwan
10Division of Neurosurgery, Department of Surgery, National Taiwan University Hospital, Taipei City, Taiwan
Copyright © 2023 by the Korean Spinal Neurosurgery Society
This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Conflict of Interest
The authors have nothing to disclose.
Funding/Support
This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Author Contribution
Conceptualization: CJH, FYT; Formal Analysis: CJH, FYT; Investigation: CJH, CYW, YHL, YCH, WCY, TWWC, WLM, WHL, FMH, FX, SHY, DML, CMC, SYC, FYT; Methodology: CJH, FYT, FX, SHY, DML, CMC; Project Administration: FYT; Writing – Original Draft: CJH; Writing – Review & Editing: FYT.
CI, confidence interval; HR, hazard ratio.
No. of subjects, n=233, no. of events=95, and no. of observations (long-form), m=13,873.
The adjusted generalized R2=0.2694 >0.15, and concordance=0.7397 (se=0.0268) >0.7 indicated an acceptable fit.
As explained in the text, the cutoff values of some continuous covariates were estimated by the smoothed effect plots of Cox model with the “p-spline” option in R.
| Characteristic | Pre-COVID era | Global pandemic | National lock-down in Taiwan | Lifting of lock-down in Taiwan | Total | p-value† |
|---|---|---|---|---|---|---|
| No. of subjects | 85 (33.07) | 100 (38.91) | 14 (5.45) | 34 (13.23) | 233 (100) | |
| Age (yr) | 0.348 | |||||
| Mean ± SD | 60.51 ± 12.48 | 62.93 ± 11.97 | 63.5 ± 7.43 | 64.5 ± 9 | 62.31 ± 11.59 | |
| Range | 23–82 | 31–92 | 52-78 | 45-82 | 23–92 | |
| Sex | 0.377 | |||||
| Female | 45 (52.94) | 45 (45.00) | 5 (35.71) | 13 (38.24) | 108 (46.35) | |
| Male | 40 (47.06) | 55 (55.00) | 9 (64.29) | 21 (61.76) | 125 (53.65) | |
| Body mass index (kg/m2) | 0.917 | |||||
| Mean ± SD | 23.01 ± 3.81 | 22.97 ± 3.86 | 22.05 ± 3.29 | 22.91 ± 3.65 | 22.92 ± 3.77 | |
| Range | 13.83–33.53 | 12.78–35.46 | 16.85–27.85 | 16.20–31.77 | 12.78–35.46 | |
| Emergent operation classification | 0.134 | |||||
| Emergent | 33 (38.82) | 33 (33.00) | 5 (35.71) | 6 (17.65) | 77 (33.05) | |
| Urgent | 18 (21.18) | 31 (31.00) | 1 (7.14) | 12 (35.29) | 62 (26.61) | |
| Elective | 34 (40.00) | 36 (36.00) | 8 (57.14) | 16 (47.06) | 94 (40.34) | |
| Surgical method | 0.014 | |||||
| Palliative surgery | 39 (45.88) | 27 (27.00) | 8 (57.14) | 8 (23.53) | 82 (35.19) | |
| Debulking surgery | 37 (43.53) | 67 (67.00) | 6 (42.86) | 23 (67.65) | 133 (57.08) | |
| En bloc spondylectomy | 9 (10.59) | 6 (6.00) | 0 (0) | 3 (8.82) | 18 (7.73) | |
| Admitted from emergency department | 0.522 | |||||
| Yes | 38 (44.71) | 51 (51.00) | 9 (64.29) | 18 (52.94) | 116 (49.79) | |
| No | 47 (55.29) | 49 (49.00) | 5 (35.71) | 16 (47.06) | 117 (50.21) | |
| Time from symptoms onset to surgeon visit (day) | 0.174 | |||||
| Mean ± SD | 41.48 ± 75.64 | 51.69 ± 113.37 | 48.73 ± 62.78 | 46.24 ± 47.62 | 46.99 ± 90.12 | |
| Range | 0.06–360.00 | 0.06–720.00 | 1.00–180.00 | 2.00–180.00 | 0.06–720.00 | |
| Time from surgeon visit to operation (hr) | 0.011 | |||||
| Mean ± SD | 75.97 ± 76.88 | 86.63 ± 89.11 | 168.79 ± 211.32 | 166.91 ± 276.78 | 99.39 ± 141.98 | 0.134 |
| Range | 1.50–504.00 | 4.50–480.00 | 7.00–720.00 | 19.00–1,632.00 | 1.50–1,632.00 | |
| Mortality | 0.027 | |||||
| Yes | 38 (44.71) | 46 (46.00) | 6 (42.86) | 6 (17.65) | 96 (41.20) | |
| No | 47 (55.29) | 54 (54.00) | 8 (57.14) | 28 (82.35) | 137 (58.80) | |
| Interval between operation and mortality (day) | <0.001 | |||||
| Mean ± SD | 642.96 ± 398.36 | 347.42 ± 244.36 | 174.21 ± 109.14 | 132.32 ± 39.21 | 413.44 ± 346.46 | |
| Range | 10.00–1,168.00 | 0.00–763.00 | 20.00–300.00 | 53.00–108.00 | 0.00–1,168.00 | |
| Metastases | 0.541 | |||||
| Synchronous metastases | 34 (40.00) | 37 (37.00) | 6 (42.86) | 25 (73.53) | 86 (36.91) | |
| Metachronous metastases | 51 (60.00) | 63 (63.00) | 8 (57.14) | 9 (26.47) | 147 (63.09) | |
| Time from diagnosis of primary cancer to diagnosis of spinal metastases (day) | 0.422 | |||||
| Mean ± SD | 765.06 ± 1,055.86 | 886.72 ± 1,409.81 | 739.29 ± 1,986.6 | 1,023.47 ± 1,241.6 | 853.43 ± 1,304.06 | |
| Range | -34.00–4,867.00 | -25.00–9,771.00 | -7.00–7,512.00 | -43.00–4,082.00 | -43.00–9,771.00 | |
| Detail of primary tumor | 0.246 | |||||
| Lung | 29 (34.12) | 29 (29.00) | 4 (28.57) | 8 (23.53) | 70 (30.04) | |
| Hepatocellular carcinoma | 4 (4.71) | 18 (18.00) | 1 (7.14) | 5 (14.71) | 28 (12.02) | |
| Breast | 11 (12.94) | 7 (7.00) | 1 (7.14) | 3 (8.82) | 22 (9.44) | |
| Prostate | 8 (9.41) | 3 (3.00) | 2 (14.29) | 5 (14.71) | 18 (7.73) | |
| Colorectal | 3 (3.53) | 6 (6.00) | 1 (7.14) | 3 (8.82) | 13 (5.58) | |
| Esophagus and gastric | 4 (4.71) | 7 (7.00) | 0 (0) | 1 (2.94) | 12 (5.15) | |
| Biliary | 5 (5.88) | 3 (3.00) | 0 (0) | 4 (11.76) | 12 (5.15) | |
| Hematology | 6 (7.06) | 4 (4.00) | 1 (7.14) | 0 (0) | 11 (4.72) | |
| OBGYN | 5 (5.88) | 2 (2.00) | 0 (0) | 1 (2.94) | 8 (3.43) | |
| Renal cell carcinoma | 2 (2.35) | 2 (2.00) | 1 (7.14) | 2 (5.88) | 7 (3.00) | |
| Others | 2 (2.35) | 3 (3.00) | 1 (7.14) | 0 (0) | 6 (2.58) | |
| Thyroid | 4 (4.71) | 2 (2.00) | 0 (0) | 0 (0) | 6 (2.58) | |
| Soft tissue/smooth muscle | 1 (1.18) | 4 (4.00) | 0 (0) | 1 (2.94) | 6 (2.58) | |
| Urinary tract | 0 (0) | 4 (4.00) | 0 (0) | 1 (2.94) | 5 (2.15) | |
| Head and neck (oral/pharynx) | 0 (0) | 4 (4.00) | 1 (7.14) | 0 (0) | 5 (2.15) | |
| Pancreas | 1 (1.18) | 2 (2.00) | 1 (7.14) | 0 (0) | 4 (1.72) | |
| ESCC scale | 0.003 | |||||
| 0 | 0 (0) | 0 (0) | 0 (0) | 1 (2.94) | 1 (0.43) | |
| 1a | 0 (0) | 1 (1.00) | 1 (7.14) | 2 (5.88) | 4 (1.72) | |
| 1b | 1 (1.18) | 4 (4.00) | 1 (7.14) | 3 (8.82) | 9 (3.86) | |
| 1c | 4 (4.71) | 3 (3.00) | 3 (21.43) | 5 (14.71) | 15 (6.44) | |
| 2 | 21 (24.71) | 15 (15.00) | 1 (7.14) | 6 (17.65) | 43 (18.45) | |
| 3 | 59 (69.41) | 77 (77.00) | 8 (57.14) | 17 (50.00) | 161 (69.10) | |
| Frankel scale | ||||||
| Preoperative | < 0.001 | |||||
| A | 0 (0) | 1 (1.00) | 2 (14.29) | 0 (0) | 3 (1.29) | |
| B | 2 (2.35) | 3 (3.00) | 0 (0) | 0 (0) | 5 (2.15) | |
| C | 11 (12.94) | 24 (24.00) | 1 (7.14) | 7 (20.59) | 43 (18.45) | |
| D | 58 (68.24) | 56 (56.00) | 5 (35.71) | 17 (50.00) | 136 (58.37) | |
| E | 14 (16.47) | 16 (16.00) | 6 (42.86) | 10 (29.41) | 46 (19.74) | |
| Postoperative (1 mo) | 0.363 | |||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (1.18) | 0 (0) | 0 (0) | 0 (0) | 1 (0.43) | |
| C | 10 (11.76) | 17 (17.00) | 3 (21.43) | 6 (17.65) | 36 (15.45) | |
| D | 51 (60.00) | 49 (49.00) | 8 (57.14) | 20 (58.82) | 128 (54.94) | |
| E | 20 (23.53) | 23 (23.00) | 1 (7.14) | 8 (23.53) | 52 (22.32) | |
| Expired | 3 (3.53) | 11 (11.00) | 2 (14.29) | 0 (0) | 16 (6.87) | |
| Postoperative (3 mo) | 0.171 | |||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (1.18) | 0 (0) | 0 (0) | 0 (0) | 1 (0.43) | |
| C | 7 (8.24) | 14 (14.00) | 0 (0) | 5 (14.71) | 26 (11.16) | |
| D | 33 (38.82) | 36 (36.00) | 7 (50.00) | 18 (52.94) | 94 (40.34) | |
| E | 30 (35.29) | 26 (26.00) | 2 (14.29) | 9 (26.47) | 67 (28.76) | |
| Expired | 14 (16.47) | 24 (24.00) | 5 (35.71) | 2 (5.88) | 45 (19.31) | |
| SINS score | 0.064 | |||||
| Mean ± SD | 11.49 ± 2.29 | 11.9 ± 2.46 | 12.21 ± 2.89 | 10.59 ± 2.83 | 11.58 ± 2.51 | |
| Range | 5–17 | 5–16 | 8–18 | 3–16 | 3–18 | |
| Tomita score | 0.007 | |||||
| Mean ± SD | 6.75 ± 2.21 | 7.63 ± 2.15 | 6.71 ± 2.87 | 6.35 ± 2.25 | 7.07 ± 2.28 | |
| Range | 2–10 | 2–10 | 2–10 | 2–10 | 2–10 | |
| Tokuhashi score | 0.063 | |||||
| Mean ± SD | 8.21 ± 2.59 | 7.31 ± 2.02 | 6.93 ± 2.97 | 7.65 ± 2.68 | 7.67 ± 2.43 | |
| Range | 2–14 | 2–13 | 2–12 | 2–14 | 2–14 | |
| Preoperative radiotherapy | 0.002 | |||||
| Yes | 5 (5.88) | 8 (8.00) | 2 (14.29) | 10 (29.41) | 25 (10.73) | |
| No | 80 (94.12) | 92 (92.00) | 12 (85.71) | 24 (70.59) | 208 (89.27) | |
| Postoperative radiotherapy within 1 month | 0.021 | |||||
| Yes | 53 (62.35) | 61 (61.00) | 4 (28.57) | 14 (41.18) | 132 (56.65) | |
| No | 32 (37.65) | 39 (39.00) | 10 (71.43) | 20 (58.82) | 101 (43.35) | |
| Postoperative chemotherapy within 1 month | 0.048 | |||||
| Yes | 41 (48.24) | 39 (39.00) | 5 (35.71) | 7 (20.59) | 92 (39.48) | |
| No | 44 (51.76) | 61 (61.00) | 9 (64.29) | 27 (79.41) | 141 (60.52) | |
| Time from operation to postoperative radiotherapy (day) | 0.063 | |||||
| Mean ± SD | 40.98 ± 54.72 | 29.66 ± 19.48 | 26.25 ± 13.67 | 42.57 ± 19.2 | 35.47 ± 37.94 | |
| Range | 5–327 | 5–128 | 15–46 | 24-81 | 5–327 | |
| Time from operation to postoperative chemotherapy (day) | 0.672 | |||||
| Mean ± SD | 45.07 ± 41.72 | 38.77 ± 40.88 | 33.6 ± 48.59 | 28.29 ± 13.72 | 40.5 ± 40.05 | |
| Range | 5–153 | 2–180 | 1–119 | 13–50 | 1–180 | |
Values are presented as number (%) or mean±standard deviation.
COVID, coronavirus disease; SD, standard deviation; OBGYN, obstetrics & gynecology; ESCC, epidural spinal cord compression; SINS, spinal instability neoplastic score.
†The listed p-values of statistical tests were calculated using the Kruskal-Wallis rank-sum test for continuous variables and the Fisher exact test for categorical variables.
| Characteristic | Alive | Dead | Total | p-value† |
|---|---|---|---|---|
| No. of subjects | 137 (58.80) | 96 (41.20) | 233 (100) | |
| Age (yr) | 0.702 | |||
| Mean ± SD | 62.15 ± 12.25 | 62.53 ± 10.62 | 62.31 ± 11.59 | |
| Range | 23–89 | 31–92 | 23–92 | |
| Sex | 0.351 | |||
| Female | 67 (48.91) | 41 (42.71) | 108 (46.35) | |
| Male | 70 (51.09) | 55 (57.29) | 125 (53.65) | |
| Emergent operation classification | < 0.001 | |||
| Emergent | 37 (27.01) | 40 (41.67) | 77 (33.05) | |
| Urgent | 30 (21.90) | 32 (33.33) | 62 (26.61) | |
| Elective | 70 (51.09) | 24 (25.00) | 94 (40.34) | |
| Surgical method | 0.017 | |||
| Palliative surgery | 43 (31.39) | 39 (40.63) | 82 (35.19) | |
| Debulking surgery | 78 (56.93) | 55 (57.29) | 133 (57.08) | |
| En bloc spondylectomy | 16 (11.68) | 2 (2.08) | 18 (7.73) | |
| Time from surgeon visit to operation (hr) | 0.253 | |||
| Mean ± SD | 101.65 ± 110.77 | 96.17 ± 177.88 | 99.39 ± 141.98 | |
| Range | 1.50–720.00 | 4.00–1,632.00 | 1.50–1,632.00 | |
| Metastases | 0.876 | |||
| Synchronous metastases | 50 (36.50) | 36 (37.50) | 86 (36.91) | |
| Metachronous metastases | 87 (63.50) | 60 (62.50) | 147 (63.09) | |
| ESCC scale | 0.046 | |||
| 0 | 1 (0.73) | 0 (0) | 1 (0.43) | |
| 1a | 4 (2.92) | 0 (0) | 4 (1.72) | |
| 1b | 7 (5.11) | 2 (2.08) | 9 (3.86) | |
| 1c | 10 (7.30) | 5 (5.21) | 15 (6.44) | |
| 2 | 31 (22.63) | 12 (12.50) | 43 (18.45) | |
| 3 | 84 (61.31) | 77 (80.21) | 161 (69.10) | |
| Frankel scale | ||||
| Preoperative | 0.075 | |||
| A | 1 (0.73) | 2 (2.08) | 3 (1.29) | |
| B | 2 (1.46) | 3 (3.13) | 5 (2.15) | |
| C | 22 (16.06) | 21 (21.88) | 43 (18.45) | |
| D | 77 (56.20) | 59 (61.46) | 136 (58.37) | |
| E | 35 (56.20) | 11 (11.46) | 46 (19.74) | |
| Postoperative (1 mo) | < 0.001 | |||
| A | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (0.73) | 0 (0) | 1 (0.43) | |
| C | 13 (9.49) | 23 (23.96) | 36 (15.45) | |
| D | 84 (61.31) | 44 (45.83) | 128 (54.94) | |
| E | 39 (28.47) | 13 (13.54) | 52 (22.32) | |
| Expired | 0 (0) | 16 (16.67) | 16 (6.87) | |
| Postoperative (3 mo) | < 0.001 | |||
| A | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (0.73) | 0 (0) | 1 (0.43) | |
| C | 16 (11.68) | 10 (10.42) | 26 (11.16) | |
| D | 66 (48.18) | 28 (29.17) | 94 (40.34) | |
| E | 54 (39.42) | 13 (13.54) | 67 (28.76) | |
| Expired | 0 (0) | 45 (46.88) | 45 (19.31) | |
| SINS score | 0.477 | |||
| Mean ± SD | 11.47 ± 2.65 | 11.74 ± 2.31 | 11.58 ± 2.51 | |
| Range | 3–18 | 5–17 | 3–18 | |
| Tomita score | 0.034 | |||
| Mean ± SD | 6.76 ± 2.43 | 7.51 ± 1.97 | 7.07 ± 2.28 | |
| Range | 2–10 | 2–10 | 2–10 | |
| Tokuhashi score | 0.004 | |||
| Mean ± SD | 8.07 ± 2.50 | 7.08 ± 2.19 | 7.67 ± 2.43 | |
| Range | 2–14 | 2–13 | 2–14 | |
| Preoperative radiotherapy | 0.576 | |||
| Yes | 16 (11.68) | 9 (9.38) | 25 (10.73) | |
| No | 121 (88.32) | 87 (90.63) | 208 (89.27) |
Values are presented as number (%) or mean±standard deviation.
SD, standard deviation; SINS, spinal instability neoplastic score.
†The listed p-values of statistical tests were calculated using the Kruskal-Wallis rank-sum test for continuous variables and the Fisher exact test for categorical variables.
| Covariate | Regression coefficient estimate | Estimated standard error | z test | p-value | Estimated hazard ratio | 95% CI of HR |
|---|---|---|---|---|---|---|
| Elective surgery | -0.5815 | 0.2932 | -1.9833 | 0.0473 | 0.55903373 | 0.314668–0.993171 |
| Lifting of lockdown | -0.9413 | 0.4477 | -2.1026 | 0.0355 | 0.3901235 | 0.162234–0.938129 |
| Tokuhashi score (per point increased) | -0.1409 | 0.0452 | -3.1163 | 0.0018 | 0.8686029 | 0.794957–0.949071 |
| Body mass index ≤ 24.6 (kg/m2) | 0.6371 | 0.2578 | 2.4709 | 0.0135 | 1.89092235 | 1.140804–3.134270 |
| Back to outpatient clinic less than once per month (at event time) | 0.5545 | 0.2338 | 2.3719 | 0.0177 | 1.74110983 | 1.101101–2.753121 |
| Urinary tract cancer | 1.1402 | 0.5432 | 2.0990 | 0.0358 | 3.12747532 | 1.078444–9.069639 |
| Frankel scale A, B, or C vs. D and E (at event time) | 1.3659 | 0.3304 | 4.1341 | < 0.0001 | 3.9191105 | 2.050976–7.488840 |
| Frankel scale A, B, or C vs. D and E × overall survival time in weeks (at event time) | -0.0042 | 0.0019 | -2.1397 | 0.0324 | 0.99581948 | 0.992005–0.999648 |
| Time from patient presentation to operation: > 33 hr in emergent surgery | 0.1874 | 0.3319 | 0.5646 | 0.5724 | 1.20607817 | 0.629322–2.311416 |
| Time from patient presentation to operation: < 59 hr and > 111 hr in urgent surgery | 0.7615 | 0.2830 | 2.6912 | 0.0071 | 2.1414947 | 1.229884–3.728807 |
| Time from patient presentation to operation: > 322 hr in elective surgery | 0.8111 | 0.6242 | 1.2994 | 0.1938 | 2.25046525 | 0.662117–7.649093 |
| Characteristic | Pre-COVID era | Global pandemic | National lock-down in Taiwan | Lifting of lock-down in Taiwan | Total | p-value† |
|---|---|---|---|---|---|---|
| No. of subjects | 85 (33.07) | 100 (38.91) | 14 (5.45) | 34 (13.23) | 233 (100) | |
| Age (yr) | 0.348 | |||||
| Mean ± SD | 60.51 ± 12.48 | 62.93 ± 11.97 | 63.5 ± 7.43 | 64.5 ± 9 | 62.31 ± 11.59 | |
| Range | 23–82 | 31–92 | 52-78 | 45-82 | 23–92 | |
| Sex | 0.377 | |||||
| Female | 45 (52.94) | 45 (45.00) | 5 (35.71) | 13 (38.24) | 108 (46.35) | |
| Male | 40 (47.06) | 55 (55.00) | 9 (64.29) | 21 (61.76) | 125 (53.65) | |
| Body mass index (kg/m2) | 0.917 | |||||
| Mean ± SD | 23.01 ± 3.81 | 22.97 ± 3.86 | 22.05 ± 3.29 | 22.91 ± 3.65 | 22.92 ± 3.77 | |
| Range | 13.83–33.53 | 12.78–35.46 | 16.85–27.85 | 16.20–31.77 | 12.78–35.46 | |
| Emergent operation classification | 0.134 | |||||
| Emergent | 33 (38.82) | 33 (33.00) | 5 (35.71) | 6 (17.65) | 77 (33.05) | |
| Urgent | 18 (21.18) | 31 (31.00) | 1 (7.14) | 12 (35.29) | 62 (26.61) | |
| Elective | 34 (40.00) | 36 (36.00) | 8 (57.14) | 16 (47.06) | 94 (40.34) | |
| Surgical method | 0.014 | |||||
| Palliative surgery | 39 (45.88) | 27 (27.00) | 8 (57.14) | 8 (23.53) | 82 (35.19) | |
| Debulking surgery | 37 (43.53) | 67 (67.00) | 6 (42.86) | 23 (67.65) | 133 (57.08) | |
| En bloc spondylectomy | 9 (10.59) | 6 (6.00) | 0 (0) | 3 (8.82) | 18 (7.73) | |
| Admitted from emergency department | 0.522 | |||||
| Yes | 38 (44.71) | 51 (51.00) | 9 (64.29) | 18 (52.94) | 116 (49.79) | |
| No | 47 (55.29) | 49 (49.00) | 5 (35.71) | 16 (47.06) | 117 (50.21) | |
| Time from symptoms onset to surgeon visit (day) | 0.174 | |||||
| Mean ± SD | 41.48 ± 75.64 | 51.69 ± 113.37 | 48.73 ± 62.78 | 46.24 ± 47.62 | 46.99 ± 90.12 | |
| Range | 0.06–360.00 | 0.06–720.00 | 1.00–180.00 | 2.00–180.00 | 0.06–720.00 | |
| Time from surgeon visit to operation (hr) | 0.011 | |||||
| Mean ± SD | 75.97 ± 76.88 | 86.63 ± 89.11 | 168.79 ± 211.32 | 166.91 ± 276.78 | 99.39 ± 141.98 | 0.134 |
| Range | 1.50–504.00 | 4.50–480.00 | 7.00–720.00 | 19.00–1,632.00 | 1.50–1,632.00 | |
| Mortality | 0.027 | |||||
| Yes | 38 (44.71) | 46 (46.00) | 6 (42.86) | 6 (17.65) | 96 (41.20) | |
| No | 47 (55.29) | 54 (54.00) | 8 (57.14) | 28 (82.35) | 137 (58.80) | |
| Interval between operation and mortality (day) | <0.001 | |||||
| Mean ± SD | 642.96 ± 398.36 | 347.42 ± 244.36 | 174.21 ± 109.14 | 132.32 ± 39.21 | 413.44 ± 346.46 | |
| Range | 10.00–1,168.00 | 0.00–763.00 | 20.00–300.00 | 53.00–108.00 | 0.00–1,168.00 | |
| Metastases | 0.541 | |||||
| Synchronous metastases | 34 (40.00) | 37 (37.00) | 6 (42.86) | 25 (73.53) | 86 (36.91) | |
| Metachronous metastases | 51 (60.00) | 63 (63.00) | 8 (57.14) | 9 (26.47) | 147 (63.09) | |
| Time from diagnosis of primary cancer to diagnosis of spinal metastases (day) | 0.422 | |||||
| Mean ± SD | 765.06 ± 1,055.86 | 886.72 ± 1,409.81 | 739.29 ± 1,986.6 | 1,023.47 ± 1,241.6 | 853.43 ± 1,304.06 | |
| Range | -34.00–4,867.00 | -25.00–9,771.00 | -7.00–7,512.00 | -43.00–4,082.00 | -43.00–9,771.00 | |
| Detail of primary tumor | 0.246 | |||||
| Lung | 29 (34.12) | 29 (29.00) | 4 (28.57) | 8 (23.53) | 70 (30.04) | |
| Hepatocellular carcinoma | 4 (4.71) | 18 (18.00) | 1 (7.14) | 5 (14.71) | 28 (12.02) | |
| Breast | 11 (12.94) | 7 (7.00) | 1 (7.14) | 3 (8.82) | 22 (9.44) | |
| Prostate | 8 (9.41) | 3 (3.00) | 2 (14.29) | 5 (14.71) | 18 (7.73) | |
| Colorectal | 3 (3.53) | 6 (6.00) | 1 (7.14) | 3 (8.82) | 13 (5.58) | |
| Esophagus and gastric | 4 (4.71) | 7 (7.00) | 0 (0) | 1 (2.94) | 12 (5.15) | |
| Biliary | 5 (5.88) | 3 (3.00) | 0 (0) | 4 (11.76) | 12 (5.15) | |
| Hematology | 6 (7.06) | 4 (4.00) | 1 (7.14) | 0 (0) | 11 (4.72) | |
| OBGYN | 5 (5.88) | 2 (2.00) | 0 (0) | 1 (2.94) | 8 (3.43) | |
| Renal cell carcinoma | 2 (2.35) | 2 (2.00) | 1 (7.14) | 2 (5.88) | 7 (3.00) | |
| Others | 2 (2.35) | 3 (3.00) | 1 (7.14) | 0 (0) | 6 (2.58) | |
| Thyroid | 4 (4.71) | 2 (2.00) | 0 (0) | 0 (0) | 6 (2.58) | |
| Soft tissue/smooth muscle | 1 (1.18) | 4 (4.00) | 0 (0) | 1 (2.94) | 6 (2.58) | |
| Urinary tract | 0 (0) | 4 (4.00) | 0 (0) | 1 (2.94) | 5 (2.15) | |
| Head and neck (oral/pharynx) | 0 (0) | 4 (4.00) | 1 (7.14) | 0 (0) | 5 (2.15) | |
| Pancreas | 1 (1.18) | 2 (2.00) | 1 (7.14) | 0 (0) | 4 (1.72) | |
| ESCC scale | 0.003 | |||||
| 0 | 0 (0) | 0 (0) | 0 (0) | 1 (2.94) | 1 (0.43) | |
| 1a | 0 (0) | 1 (1.00) | 1 (7.14) | 2 (5.88) | 4 (1.72) | |
| 1b | 1 (1.18) | 4 (4.00) | 1 (7.14) | 3 (8.82) | 9 (3.86) | |
| 1c | 4 (4.71) | 3 (3.00) | 3 (21.43) | 5 (14.71) | 15 (6.44) | |
| 2 | 21 (24.71) | 15 (15.00) | 1 (7.14) | 6 (17.65) | 43 (18.45) | |
| 3 | 59 (69.41) | 77 (77.00) | 8 (57.14) | 17 (50.00) | 161 (69.10) | |
| Frankel scale | ||||||
| Preoperative | < 0.001 | |||||
| A | 0 (0) | 1 (1.00) | 2 (14.29) | 0 (0) | 3 (1.29) | |
| B | 2 (2.35) | 3 (3.00) | 0 (0) | 0 (0) | 5 (2.15) | |
| C | 11 (12.94) | 24 (24.00) | 1 (7.14) | 7 (20.59) | 43 (18.45) | |
| D | 58 (68.24) | 56 (56.00) | 5 (35.71) | 17 (50.00) | 136 (58.37) | |
| E | 14 (16.47) | 16 (16.00) | 6 (42.86) | 10 (29.41) | 46 (19.74) | |
| Postoperative (1 mo) | 0.363 | |||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (1.18) | 0 (0) | 0 (0) | 0 (0) | 1 (0.43) | |
| C | 10 (11.76) | 17 (17.00) | 3 (21.43) | 6 (17.65) | 36 (15.45) | |
| D | 51 (60.00) | 49 (49.00) | 8 (57.14) | 20 (58.82) | 128 (54.94) | |
| E | 20 (23.53) | 23 (23.00) | 1 (7.14) | 8 (23.53) | 52 (22.32) | |
| Expired | 3 (3.53) | 11 (11.00) | 2 (14.29) | 0 (0) | 16 (6.87) | |
| Postoperative (3 mo) | 0.171 | |||||
| A | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (1.18) | 0 (0) | 0 (0) | 0 (0) | 1 (0.43) | |
| C | 7 (8.24) | 14 (14.00) | 0 (0) | 5 (14.71) | 26 (11.16) | |
| D | 33 (38.82) | 36 (36.00) | 7 (50.00) | 18 (52.94) | 94 (40.34) | |
| E | 30 (35.29) | 26 (26.00) | 2 (14.29) | 9 (26.47) | 67 (28.76) | |
| Expired | 14 (16.47) | 24 (24.00) | 5 (35.71) | 2 (5.88) | 45 (19.31) | |
| SINS score | 0.064 | |||||
| Mean ± SD | 11.49 ± 2.29 | 11.9 ± 2.46 | 12.21 ± 2.89 | 10.59 ± 2.83 | 11.58 ± 2.51 | |
| Range | 5–17 | 5–16 | 8–18 | 3–16 | 3–18 | |
| Tomita score | 0.007 | |||||
| Mean ± SD | 6.75 ± 2.21 | 7.63 ± 2.15 | 6.71 ± 2.87 | 6.35 ± 2.25 | 7.07 ± 2.28 | |
| Range | 2–10 | 2–10 | 2–10 | 2–10 | 2–10 | |
| Tokuhashi score | 0.063 | |||||
| Mean ± SD | 8.21 ± 2.59 | 7.31 ± 2.02 | 6.93 ± 2.97 | 7.65 ± 2.68 | 7.67 ± 2.43 | |
| Range | 2–14 | 2–13 | 2–12 | 2–14 | 2–14 | |
| Preoperative radiotherapy | 0.002 | |||||
| Yes | 5 (5.88) | 8 (8.00) | 2 (14.29) | 10 (29.41) | 25 (10.73) | |
| No | 80 (94.12) | 92 (92.00) | 12 (85.71) | 24 (70.59) | 208 (89.27) | |
| Postoperative radiotherapy within 1 month | 0.021 | |||||
| Yes | 53 (62.35) | 61 (61.00) | 4 (28.57) | 14 (41.18) | 132 (56.65) | |
| No | 32 (37.65) | 39 (39.00) | 10 (71.43) | 20 (58.82) | 101 (43.35) | |
| Postoperative chemotherapy within 1 month | 0.048 | |||||
| Yes | 41 (48.24) | 39 (39.00) | 5 (35.71) | 7 (20.59) | 92 (39.48) | |
| No | 44 (51.76) | 61 (61.00) | 9 (64.29) | 27 (79.41) | 141 (60.52) | |
| Time from operation to postoperative radiotherapy (day) | 0.063 | |||||
| Mean ± SD | 40.98 ± 54.72 | 29.66 ± 19.48 | 26.25 ± 13.67 | 42.57 ± 19.2 | 35.47 ± 37.94 | |
| Range | 5–327 | 5–128 | 15–46 | 24-81 | 5–327 | |
| Time from operation to postoperative chemotherapy (day) | 0.672 | |||||
| Mean ± SD | 45.07 ± 41.72 | 38.77 ± 40.88 | 33.6 ± 48.59 | 28.29 ± 13.72 | 40.5 ± 40.05 | |
| Range | 5–153 | 2–180 | 1–119 | 13–50 | 1–180 | |
| Characteristic | Alive | Dead | Total | p-value† |
|---|---|---|---|---|
| No. of subjects | 137 (58.80) | 96 (41.20) | 233 (100) | |
| Age (yr) | 0.702 | |||
| Mean ± SD | 62.15 ± 12.25 | 62.53 ± 10.62 | 62.31 ± 11.59 | |
| Range | 23–89 | 31–92 | 23–92 | |
| Sex | 0.351 | |||
| Female | 67 (48.91) | 41 (42.71) | 108 (46.35) | |
| Male | 70 (51.09) | 55 (57.29) | 125 (53.65) | |
| Emergent operation classification | < 0.001 | |||
| Emergent | 37 (27.01) | 40 (41.67) | 77 (33.05) | |
| Urgent | 30 (21.90) | 32 (33.33) | 62 (26.61) | |
| Elective | 70 (51.09) | 24 (25.00) | 94 (40.34) | |
| Surgical method | 0.017 | |||
| Palliative surgery | 43 (31.39) | 39 (40.63) | 82 (35.19) | |
| Debulking surgery | 78 (56.93) | 55 (57.29) | 133 (57.08) | |
| En bloc spondylectomy | 16 (11.68) | 2 (2.08) | 18 (7.73) | |
| Time from surgeon visit to operation (hr) | 0.253 | |||
| Mean ± SD | 101.65 ± 110.77 | 96.17 ± 177.88 | 99.39 ± 141.98 | |
| Range | 1.50–720.00 | 4.00–1,632.00 | 1.50–1,632.00 | |
| Metastases | 0.876 | |||
| Synchronous metastases | 50 (36.50) | 36 (37.50) | 86 (36.91) | |
| Metachronous metastases | 87 (63.50) | 60 (62.50) | 147 (63.09) | |
| ESCC scale | 0.046 | |||
| 0 | 1 (0.73) | 0 (0) | 1 (0.43) | |
| 1a | 4 (2.92) | 0 (0) | 4 (1.72) | |
| 1b | 7 (5.11) | 2 (2.08) | 9 (3.86) | |
| 1c | 10 (7.30) | 5 (5.21) | 15 (6.44) | |
| 2 | 31 (22.63) | 12 (12.50) | 43 (18.45) | |
| 3 | 84 (61.31) | 77 (80.21) | 161 (69.10) | |
| Frankel scale | ||||
| Preoperative | 0.075 | |||
| A | 1 (0.73) | 2 (2.08) | 3 (1.29) | |
| B | 2 (1.46) | 3 (3.13) | 5 (2.15) | |
| C | 22 (16.06) | 21 (21.88) | 43 (18.45) | |
| D | 77 (56.20) | 59 (61.46) | 136 (58.37) | |
| E | 35 (56.20) | 11 (11.46) | 46 (19.74) | |
| Postoperative (1 mo) | < 0.001 | |||
| A | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (0.73) | 0 (0) | 1 (0.43) | |
| C | 13 (9.49) | 23 (23.96) | 36 (15.45) | |
| D | 84 (61.31) | 44 (45.83) | 128 (54.94) | |
| E | 39 (28.47) | 13 (13.54) | 52 (22.32) | |
| Expired | 0 (0) | 16 (16.67) | 16 (6.87) | |
| Postoperative (3 mo) | < 0.001 | |||
| A | 0 (0) | 0 (0) | 0 (0) | |
| B | 1 (0.73) | 0 (0) | 1 (0.43) | |
| C | 16 (11.68) | 10 (10.42) | 26 (11.16) | |
| D | 66 (48.18) | 28 (29.17) | 94 (40.34) | |
| E | 54 (39.42) | 13 (13.54) | 67 (28.76) | |
| Expired | 0 (0) | 45 (46.88) | 45 (19.31) | |
| SINS score | 0.477 | |||
| Mean ± SD | 11.47 ± 2.65 | 11.74 ± 2.31 | 11.58 ± 2.51 | |
| Range | 3–18 | 5–17 | 3–18 | |
| Tomita score | 0.034 | |||
| Mean ± SD | 6.76 ± 2.43 | 7.51 ± 1.97 | 7.07 ± 2.28 | |
| Range | 2–10 | 2–10 | 2–10 | |
| Tokuhashi score | 0.004 | |||
| Mean ± SD | 8.07 ± 2.50 | 7.08 ± 2.19 | 7.67 ± 2.43 | |
| Range | 2–14 | 2–13 | 2–14 | |
| Preoperative radiotherapy | 0.576 | |||
| Yes | 16 (11.68) | 9 (9.38) | 25 (10.73) | |
| No | 121 (88.32) | 87 (90.63) | 208 (89.27) |
CI, confidence interval; HR, hazard ratio.
No. of subjects, n=233, no. of events=95, and no. of observations (long-form), m=13,873.
The adjusted generalized R2=0.2694 >0.15, and concordance=0.7397 (se=0.0268) >0.7 indicated an acceptable fit.
As explained in the text, the cutoff values of some continuous covariates were estimated by the smoothed effect plots of Cox model with the “p-spline” option in R.
Values are presented as number (%) or mean±standard deviation.
COVID, coronavirus disease; SD, standard deviation; OBGYN, obstetrics & gynecology; ESCC, epidural spinal cord compression; SINS, spinal instability neoplastic score.
The listed p-values of statistical tests were calculated using the Kruskal-Wallis rank-sum test for continuous variables and the Fisher exact test for categorical variables.
Values are presented as number (%) or mean±standard deviation.
SD, standard deviation; SINS, spinal instability neoplastic score.
The listed p-values of statistical tests were calculated using the Kruskal-Wallis rank-sum test for continuous variables and the Fisher exact test for categorical variables.