Table 1. Characteristics of robotic-assisted laparoscopic prostatectomy cohort by body mass index (BMI) category.
| Characteristic | All data (n=691) | Underweight/normala (n=101) | Overweightb (n=300) | Obesec (n=290) | p-value |
|---|---|---|---|---|---|
| Follow-up (mo) | 17.8 (4.8–41.6) | 17.6 (3.7–41.8) | 17.0 (4.9–42.3) | 18.6 (4.9–40.4) | 0.95 |
| Missing | 34 | 8 | 16 | 10 | |
| Demographic factors | |||||
| Race/ethnicity | |||||
| White | 676 (97.8) | 98 (97.0) | 296 (98.7) | 282 (97.2) | 0.22 |
| Black | 13 (1.9) | 2 (2.0) | 4 (1.3) | 7 (2.4) | |
| Asian | 1 (0.1) | 1 (1.0) | 0 (0) | 0 (0) | |
| Missing | 1 (0.1) | 0 (0) | 0 (0) | 1 (0.34) | |
| Age (y) | 59.1±6.4 | 59.1±6.94 | 59.6±6.24 | 58.7±6.2 | 0.17 |
| Preoperative: smoking status | |||||
| Never | 303 (43.8) | 46 (45.5) | 128 (42.7) | 129 (44.5) | 0.01 |
| Prior | 273 (39.5) | 26 (25.7) | 123 (41.0) | 124 (42.8) | |
| Current | 94 (13.6) | 23 (22.8) | 40 (13.3) | 31 (10.7) | |
| Missing | 21 (3.0) | 6 (5.9) | 9 (3.0) | 6 (2.1) | |
| Diabetes | 59 (8.5) | 5 (5.0) | 24 (8.0) | 30 (10.3) | 0.22 |
| Coronary artery disease | 40 (5.8) | 3 (3.0) | 15 (5.0) | 22 (7.6) | 0.17 |
| Hypertension | 293 (42.4) | 27 (26.7) | 100 (33.3) | 166 (57.2) | <0.0001 |
| Preoperative factors | |||||
| PSA (ng/dL) | 5.10 (4.05–7.07) | 5.38 (4.19–7.17) | 4.96 (3.80–7.09) | 5.19 (4.17–7.03) | 0.81 |
| Missing | 30 | 5 | 16 | 9 | |
| TRUS volume | 33.04 (26.28–45.42) | 30 (21.49–42.68) | 31.94 (26.05–42.18) | 35.82 (28.40–47.98) | 0.14 |
| Missing | 0299 | 42 | 0136 | 0121 | |
| Intraoperative factors | |||||
| Length of operation (min) | 195.5±46.1 | 190.9±48.89 | 193.0±45.3 | 199.8±45.69 | 0.12 |
| Missing | 20 | 3 | 7 | 10 | |
| Nerve sparing | |||||
| Unilateral | 52 (7.5) | 8 (7.9) | 26 (8.7) | 18 (6.2) | 0.62 |
| Bilateral | 475 (68.7) | 67 (66.3) | 211 (70.3) | 197 (67.9) | |
| No preservation | 95 (13.8) | 14 (13.9) | 34 (11.3) | 47 (16.2) | |
| Not reported | 69 (10.0) | 12 (11.9) | 29 (9.7) | 28 (9.7) | |
| Estimated blood loss (mL) | 150 (100–250) | 150 (100–250) | 150 (100–250) | 200 (100–300) | 0.02 |
| Missing | 20 | 2 | 11 | 7 | |
| Pathologic staging | |||||
| Tumor stage | |||||
| Negative | 6 (0.87) | 0 (0) | 3 (1.0) | 3 (1.0) | 0.32 |
| pT2a | 104 (15.1) | 21 (20.8) | 38 (12.7) | 45 (15.5) | |
| pT2b | 6 (0.87) | 1 (0.99) | 3 (1.0) | 2 (0.69) | |
| pT2c | 479 (69.3) | 62 (61.4) | 224 (74.7) | 193 (66.6) | |
| pT3a | 47 (6.8) | 7 (6.9) | 19 (6.3) | 21 (7.2) | |
| pT3b | 41 (5.9) | 9 (8.9) | 11 (3.7) | 21 (7.2) | |
| Missing | 8 (1.2) | 1 (0.99) | 2 (0.67) | 5 (1.7) | |
| Lymph nodes | |||||
| N0 | 67 (9.7) | 14 (13.9) | 31 (10.3) | 22 (7.6) | 0.14 |
| N1 | 8 (1.2) | 3 (3.0) | 1 (0.33) | 4 (1.4) | |
| NX | 611 (88.4) | 83 (82.2) | 267 (89.0) | 261 (90.0) | |
| Missing | 5 (0.7) | 1 (0.99) | 1 (0.33) | 3 (1.0) | |
| Gleason Score | |||||
| 5 | 5 (0.7) | 1 (0.99) | 2 (0.67) | 2 (0.69) | 0.55 |
| 6 | 308 (44.6) | 43 (42.6) | 138 (46.0) | 127 (43.8) | |
| 7 | 290 (42.0) | 42 (41.6) | 132 (44.0) | 116 (40.0) | |
| 8 | 42 (6.1) | 6 (5.9) | 14 (4.7) | 22 (7.6) | |
| 9 | 33 (4.8) | 7 (6.9) | 8 (2.7) | 18 (6.2) | |
| 10 | 3 (0.4) | 1 (0.99) | 2 (0.67) | 0 (0) | |
| Missing | 10 (1.5) | 1 (0.99) | 4 (1.3) | 5 (1.7) | |
| Margin status | |||||
| Negative | 433 (62.7) | 67 (66.3) | 194 (64.7) | 172 (59.3) | 0.64 |
| Positive | 249 (36.0) | 33 (32.7) | 102 (34.0) | 114 (39.3) | |
| Missing | 9 (1.3) | 1 (0.99) | 4 (1.3) | 4 (1.4) | |
| Year of surgery | |||||
| 2004 | 3 (0.4) | 0 (0) | 1 (0.3) | 2 (0.7) | 0.23 |
| 2005 | 27 (3.9) | 3 (3.0) | 13 (4.3) | 11 (3.8) | |
| 2006 | 55 (8.0) | 5 (5.0) | 21 (7.0) | 29 (10.0) | |
| 2007 | 90 (13.0) | 14 (13.9) | 45 (15.0) | 31 (10.7) | |
| 2008 | 116 (16.8) | 21 (20.8) | 52 (17.3) | 43 (14.8) | |
| 2009 | 75 (10.9) | 16 (15.8) | 31 (10.3) | 28 (9.7) | |
| 2010 | 93 (13.5) | 11 (10.9) | 39 (13.0) | 43 (14.8) | |
| 2011 | 113 (16.4) | 11 (10.9) | 44 (14.7) | 58 (20.0) | |
| 2012 | 58 (8.4) | 8 (7.9) | 26 (8.7) | 24 (8.3) | |
| 2013 | 58 (8.4) | 12 (11.9) | 28 (9.3) | 18 (6.2) | |
| 2014 | 3 (0.4) | 0 (0) | 0 (0) | 3 (1.0) |
Values are presented as median (interquartile range), number (%), or mean±standard deviation.
PSA, prostate-specific antigen; TRUS, transrectal ultrasound.
a:BMI<24.9 kg/m2. b:BMI, 25–29.9 kg/m2. c:BMI>30 kg/m2.