Influence of body mass index on oncological outcomes in patients with upper urinary tract urothelial carcinoma treated with radical nephroureterectomy.
OBJECTIVE
To investigate the association between body mass index and oncological outcomes in Chinese patients who had undergone radical nephroureterectomy for upper urinary tract urothelial carcinoma.


METHODS
Between August 1998 and October 2009, 236 consecutive Chinese patients underwent radical nephroureterectomy for upper urinary tract urothelial carcinoma at Sun Yat-sen University Cancer Center (Guangzhou, China). Body mass index data were available for 230 (97.5%) of these patients. All 230 patients were classified into three groups according to the body mass index criteria for Asians, issued by the Asia Cohort Consortium: underweight, body mass index <18.5 kg/m(2) (n = 21, 9.1%); normal weight, body mass index ≥18.5 and <25 kg/m(2) (n = 151, 65.7%); and obesity, body mass index ≥25 kg/m(2), (n = 58, 25.2%). Spearman's rank correlation, Kaplan-Meier plots and Cox proportional hazards regression model were used to analyze the data.


RESULTS
Being underweight was significantly associated with lymph node metastasis (P = 0.017) and Eastern Cooperative Oncology Group performance status (P = 0.003). Univariate analysis showed recurrence-free survival and cancer-specific survival were significantly worse in underweight patients than in patients with normal weight or obese patients. After adjustments for other clinicopathological variables, multivariate analysis confirmed that recurrence-free survival and cancer-specific survival were significantly worse in underweight patients than in patients with normal weight or obese patients (recurrence-free survival P = 0.014, cancer-specific survival P = 0.015).


CONCLUSIONS
Preoperative underweight is an independent predictor of unfavorable recurrence-free survival and cancer-specific survival in Chinese patients with upper urinary tract urothelial carcinoma treated by radical nephroureterectomy, whereas obesity is associated with superior recurrence-free survival and cancer-specific survival. Further studies, including a multi-institutional, prospective, Asian cohort study, are required to confirm these findings.
State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China; Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
Jian-Ye
JY
Liu
Yong-Hong
YH
Li
Zhou-Wei
ZW
Liu
Zhi-Ling
ZL
Zhang
Yun-Lin
YL
Ye
Kai
K
Yao
Li-Juan
LJ
Jiang
Hui
H
Han
Zi-Ke
ZK
Qin
Fang-Jian
FJ
Zhou
D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy / Q000379:methods*; D009399:Nephrons / Q000473:pathology / Q000601:surgery; D009765:Obesity / Q000401:mortality*; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D013851:Thinness / Q000401:mortality*; D014513:Ureter / Q000473:pathology / Q000601:surgery; D014516:Ureteral Neoplasms / Q000401:mortality* / Q000556:secondary / Q000601:surgery*; D019459:Urothelium / Q000473:pathology / Q000601:surgery
body mass index; nephroureterectomy; prognosis; survival; upper urinary tract urothelial carcinoma