Perioperative outcomes and survival of radical cystectomy as a function of body mass index

Table 1 Preoperative patient characteristics

		Normal Weight(BMI 18.5-24.9)	Underweight(BMI < 18.5)	Overweight(BMI 25.0-29.9)	Obese(BMI > 30)	P value
Age at surgery (median, IQR), yr		70 (63-76)	78 (68-79)	70 (61-76)	67 (58-72)	0.126
Gender	Male	74 (66%)	4 (44%)	130 (81%)	106 (75%)	0.005
	Female	39 (35%)	5 (56%)	30 (19%)	36 (25%)
Clinical tumor stage	cT0	1 (1%)	0 (0%)	1 (1%)	1 (1%)	0.05
	cTis	0 (0%)	0 (0%)	8 (5%)	11 (8%)
	cTa	7 (7%)	1 (11%)	9 (6%)	10 (8%)
	cT1	30 (28%)	2 (22%)	26 (17%)	35 (26%)
	cT2	65 (61%)	4 (44%)	103 (67%)	67 (50%)
	cT3	3 (3%)	2 (22%)	4 (3%)	5 (4%)
	cT4	1 (1%)	0 (0%)	3 (2%)	4 (3%)
Prior intravesical therapy	No	86 (78%)	6 (67%)	113 (71%)	83 (59%)	0.018
	Yes	25 (22%)	3 (33%)	47 (29%)	57 (41%)
Prior neoadjuvant chemotherapy	No	100 (90%)	9 (100%)	150 (94%)	129 (92%)	0.478
	Yes	11 (10%)	0 (0%)	9 (6%)	11 (8%)
Race	Caucasian	105 (92%)	9 (100%)	151 (94%)	134 (94%)	0.492
	Hispanic	3 (3%)	0 (0%)	0 (0%)	0 (0%)
	Black	3 (3%)	0 (0%)	6 (4%)	7 (5%)
	Asian	1 (1%)	0 (0%)	2 (1%)	0 (0%)
	Unknown	1 (1%)	0 (0%)	1 (1%)	1 (1%)
Hypertension	No	52 (46%)	2 (22%)	73 (46%)	33 (23%)	< 0.001
	Yes	60 (54%)	7 (78%)	87 (54%)	108 (77%)
Diabetes mellitus, type II	No	99 (88%)	8 (89%)	132 (82%)	100 (71%)	0.006
	Yes	13 (12%)	1 (11%)	28 (18%)	40 (29%)
Coronary artery disease	No	89 (80%)	9 (100%)	125 (78%)	103 (74%)	0.248
	Yes	23 (20%)	0 (0%)	35 (22%)	37 (26%)
Cardiac arrhythmia	No	102 (91%)	7 (78%)	143 (89%)	129 (92%)	0.491
	Yes	10 (9%)	2 (22%)	17 (11%)	11 (8%)
History of coronary vascular accident	No	106 (95%)	8 (89%)	156 (97%)	139 (99%)	0.068
	Yes	6 (5%)	1 (11%)	4 (3%)	1 (1%)
Pulmonary disease	No	94 (84%)	7 (78%)	147 (92%)	115 (82%)	0.063
	Yes	18 (16%)	2 (22%)	13 (8%)	25 (18%)
Liver disease	No	110 (98%)	8 (89%)	159 (99%)	138 (99%)	0.077
	Yes	2 (2%)	1 (11%)	1 (1%)	1 (1%)
Nephrolithiasis	No	101 (91%)	9 (100%)	149 (93%)	126 (90%)	0.606
	Yes	10 (9%)	0 (0%)	11 (7%)	14 (10%)
Preoperative renal function	Normal	58 (72%)	7 (88%)	79 (70%)	70 (71%)	0.652
	CKD stage 3	19 (24%)	1 (12%)	31 (28%)	26 (27%)
	CKD stage 4	2 (2%)	0 (0%)	2 (2%)	2 (2%)
	CKD stage 5	2 (2%)	0 (0%)	0 (0%)	0 (0%)
Smoking history	No	27 (24%)	1 (11%)	42 (27%)	36 (26%)	0.76
	Yes	84 (76%)	8 (89%)	116 (73%)	103 (74%)

BMI: Body mass index; CKD: Chronic kidney disease; IQR: Inter-quartile range.

Table 2 Postoperative patient characteristics

		Normal weight(BMI 18.5-24.9)	Underweight(BMI < 18.5)	Overweight(BMI 25.0-29.9)	Obese(BMI > 30)	P value
Length of stay (median, IQR), d		8 (7-10)	13 (10-16)	8 (7-11)	9 (7-14)	0.054
Prolonged length of stay (> 7 d)	No	39 (35%)	0 (0%)	61 (38%)	49 (35%)	0.137
	Yes	73 (65%)	9 (100%)	99 (62%)	93 (65%)
Estimated blood loss (median, IQR), mL		500 (400-700)	600 (450-925)	700 (500-1000)	800 (600-1100)	< 0.001
Urinary diversion	Ileal conduit	70 (61.9%)	8 (88.9%)	88 (55%)	68 (47.9%)	0.160
	Orthotopic ileal neobladder	27 (23.9%)	1 (11.1%)	58 (26.2%)	59 (41.5%)
	Continent cutaneous diversion	14 (12.3%)	0 (0%)	12 (7.4%)	11 (7.7%)
	Cutaneous ureterostomy	0 (0%)	0 (0%)	1 (0.6%)	0 (0%)
	None	4 (3.5%)	0 (0%)	2 (1.2%)	1 (0.7%)
Pathologic tumor/nodal stage	No evidence of disease (pT0)	8 (7%)	0 (0%)	2 (1%)	9 (6%)	0.01
	Localized disease (pT0-2bN0)	45 (40%)	2 (22%)	73 (46%)	76 (53%)
	Locally advanced disease (pT3-4bN0)	25 (22%)	6 (67%)	49 (30%)	33 (23%)
	Solitary nodal metastasis (pT × N1)	12 (11%)	0 (0%)	14 (9%)	12 (9%)
	Multiple nodal metastases (pT × N2-3)	23 (20%)	1 (11%)	22 (14%)	12 (9%)
Readmission within 30 d	No	83 (75%)	6 (67%)	113 (71%)	97 (70%)	0.85
	Yes	28 (25%)	3 (33%)	46 (29%)	41 (30%)
Adjuvant chemotherapy	No	74 (67%)	7 (78%)	105 (66%)	93 (67%)	0.907
	Yes	36 (33%)	2 (22%)	54 (34%)	45 (33%)
Recurrence of disease	No	81 (72%)	5 (56%)	113 (71%)	97 (69%)	0.031
	Yes	31 (28%)	4 (44%)	47 (29%)	44 (31%)
Deceased	No	59 (52%)	2 (22%)	95 (59%)	91 (64%)	0.727
	Yes	54 (48%)	7 (78%)	65 (41%)	50 (36%)

BMI: Body mass index; IQR: Inter-quartile range.

Table 3 Pairwise comparison of disease specific survival according to body mass index

	BMI	0		1		2		3
		χ2	Sig.	χ2	Sig.	χ2	Sig.	χ2	Sig.
Log rank (Mantel-cox)	0			1.204	0.272	2.144	0.143	7.160	0.007
	1	1.204	0.272			0.961	0.327	5.838	0.0162
	2	2.144	0.143	0.961	0.327			2.189	0.139
	3	7.160	0.0071	5.838	0.016	2.189	0.139

¹DSS for underweight vs obese: 0.007.

²DSS for obese vs normal: 0.016. BMI: Body mass index; DSS: Disease specific survival; 0: Underweight; 1: Normal; 2: Overweight; 3: Obese.

Table 4 Cox stepwise multivariate regression

		HR (95%CI)	P value
Age at surgery ≥ 65 yr		1.62 (1.15-2.29)	0.006
Gender			0.330
BMI	Normal weight (BMI 18.5-24.9)	Referent	0.015
	Underweight (BMI ≤ 18.5)	3.13 (1.39-7.07)	0.006
	Overweight (BMI 25.0-29.9)	0.94 (0.64-1.38)	0.764
	Obese (BMI ≥ 30)	0.83 (0.56-1.24)	0.370
Coronary artery disease			0.808
Cardiac arrhythmia			0.722
Pulmonary disease			0.192
Hypertension			0.110
Diabetes mellitus, type II			0.217
Smoking history			0.657
Intravesical therapy			0.560
Neoadjuvant chemotherapy		2.02 (1.14-3.56)	0.015
Adjuvant chemotherapy			0.251
Pathologic stage	pT0	Referent	< 0.001
	pT1-2N0	0.78 (0.30-1.99)	0.602
	pT3-4N0	1.47 (0.56-3.80)	0.430
	pT × N1	2.48 (0.91-6.77)	0.076
	pT × N2-3	3.73 (1.43-9.74)	0.007

BMI: Body mass index.