hepatocellular carcinoma ( hcc ) is one of the most common cancers worldwide especially in china [ 13 ] .
the high hcc rates in china largely reflect the elevated prevalence of chronic hepatitis b virus ( hbv ) infection . in developed countries such as united states , nonalcoholic fatty liver disease ( nafld ) , associated with obesity ,
less study focused on the effect of obesity on hcc especially in the relationship between bmi and hcc .
no study has focused on the effect of waistline on the surgical outcome of hcc patients .
so , this study is about the influence of body mass index ( bmi ) and waistline on complications , postoperative death and long - time survival in patients undergoing surgery for hcc .
between january 2007 and december 2012 , we retrospectively reviewed the database of 136 patients underwent hepatic resection for hcc at the department of surgery of the fourth affiliated hospital of zhejiang university school of medicine .
this retrospective study had been performed with the approval of the ethics committee of the fourth affiliated hospital of zhejiang university school of medicine and was in compliance with the helsinki declaration . written informed consent was given by participants for their clinical records to be used in this study .
we enrolled 136 patients and divided them into 4 groups : group a , bmi < 25 ; group b , bmi 25 ; group c , waistline < 90 cm in males or waistline < 80 cm in females ; group d , waistline 90 cm in males or waistline 80 cm in females .
there were 61 patients ( 44.9% ) in group a , 75 patients ( 55.1% ) in group b , 58 patients ( 42.6% ) in group c , and 78 patients ( 57.4% ) in group d. all patients followed the same preoperative evaluation protocol , including blood biochemistry , ultrasonography , and computed tomography of the liver .
the criteria for resection included good general condition , absence of essential organ dysfunction and distant metastasis , and liver function ( child a or b , icg r15 < 15% ) .
follow - up data were obtained by direct communication with patients after they underwent hepatic resection .
survival analysis , including overall survival and disease - free survival , was estimated by the kaplan - meier survival method and compared using the log - rank test .
all statistical analyses were performed using statistical software ( spss 13.0 for windows , spss , chicago , il ) at a significant level of p<0.05 .
there were 110 ( 80.9% ) men and 26 ( 19.1% ) women who underwent hepatectomy .
the median age was 43 years ; 118 ( 86.8% ) patients were ages < 60 years and 18 ( 13.2% ) patients were older than 60 years .
there were 61 ( 44.9 ) patients with normal bmi ( < 25 ) and 75 ( 55.1% ) patients were overweight or obese ( bmi 25 ) .
fifty - eight patients ( 42.6% ) belong to group c and 78 patients ( 57.4% ) belong to group d. ninety - seven ( 71.3% ) patients had positive hepatitis b and 39 ( 28.7% ) patients without hbv .
histopathology of the hcc confirmed vascular invasion in 41 patients ( 30.1% ) and liver cirrhosis in 65 ( 47.8% ) patients .
surgical results confirmed capsular formation in 54 ( 39.7% ) patients and 51 ( 37.5% ) patients with solitary hcc ( table 1 ) .
the intraoperative and postoperative data including major complications of 136 patients with hcc are shown in table 2 and supplementary table 1 .
the median hospital stay was 11 days in group a and 12 days in group b , with no significant difference between the 2 groups ( p=0.373 ) .
a , 23 ( 37.7% ) patients had blood loss 1000 ml compared to 29 ( 38.7% ) patients in group b. there was no hospital death in group a and 1 ( 1.3% ) hospital death in group b. however , no significant difference was found between the 2 groups . there were no significant differences in overall postoperative complication rate between group a and group b , although pulmonary infection showed a significant difference between these 2 groups ( p=0.017 ) .
seven ( 11.5% ) patients had complications in group a compared to 9 ( 12% ) patients in group b. the most common complications in group a were ascites and wound infection , while the most common complications in group b were pulmonary infection and wound infection .
variables that might affect overall survival of patients with hcc after hepatic resection were analyzed in this study .
on univariate analysis of the prognostic factors , we found that patients with bmi 25 , waistline 90 cm ( or 80 cm in women ) and vascular invasion had poor overall survival than that without these variables ( p=0.032 , p=0.017 , p=0.009 ) .
the other variables such as sex , afp level , and blood loss were not the significant prognostic factors of overall survival .
on multivariate analysis , however , only vascular invasion and waistline were significantly associated with overall survival ( p=0.031 , p=0.039 ) .
the other variables , including bmi , were not independent prognostic factors of overall survival on multivariate analysis ( table 3 ) .
the overall survival curves of hcc patients according to the bmi are shown in figure 1 .
the 1- , 3- , and 5-year overall survival rates of group a were 95% , 81% , and 16% , respectively .
the 1- , 3- , and 5-year disease - free survival rates of these patients were 78% , 38% and 4% , respectively ( figure 1 ) .
however , there was no significant difference between the 2 groups in disease - free survival ( p=0.235 ) .
the overall and disease - free survival curves of hcc patients affected by waistline were shown in figure 2 .
the 1- , 3- , and 5-year overall survival rates of group c were 97% , 88% , respectively , and 15% compared to 96% , 68% , 15% , respectively , in group d. the 1- , 3- , and 5-year disease - free survival rates of group c were 84% , 40% and 6% , respectively .
group c had significant better overall survival and disease - free survival than group d ( p=0.028 , p=0.048 ) .
there were 110 ( 80.9% ) men and 26 ( 19.1% ) women who underwent hepatectomy .
the median age was 43 years ; 118 ( 86.8% ) patients were ages < 60 years and 18 ( 13.2% ) patients were older than 60 years .
there were 61 ( 44.9 ) patients with normal bmi ( < 25 ) and 75 ( 55.1% ) patients were overweight or obese ( bmi 25 ) .
fifty - eight patients ( 42.6% ) belong to group c and 78 patients ( 57.4% ) belong to group d. ninety - seven ( 71.3% ) patients had positive hepatitis b and 39 ( 28.7% ) patients without hbv .
histopathology of the hcc confirmed vascular invasion in 41 patients ( 30.1% ) and liver cirrhosis in 65 ( 47.8% ) patients .
surgical results confirmed capsular formation in 54 ( 39.7% ) patients and 51 ( 37.5% ) patients with solitary hcc ( table 1 ) .
the intraoperative and postoperative data including major complications of 136 patients with hcc are shown in table 2 and supplementary table 1 .
the median hospital stay was 11 days in group a and 12 days in group b , with no significant difference between the 2 groups ( p=0.373 ) .
a , 23 ( 37.7% ) patients had blood loss 1000 ml compared to 29 ( 38.7% ) patients in group b. there was no hospital death in group a and 1 ( 1.3% ) hospital death in group b. however , no significant difference was found between the 2 groups . there were no significant differences in overall postoperative complication rate between group a and group b , although pulmonary infection showed a significant difference between these 2 groups ( p=0.017 ) .
seven ( 11.5% ) patients had complications in group a compared to 9 ( 12% ) patients in group b. the most common complications in group a were ascites and wound infection , while the most common complications in group b were pulmonary infection and wound infection .
variables that might affect overall survival of patients with hcc after hepatic resection were analyzed in this study .
on univariate analysis of the prognostic factors , we found that patients with bmi 25 , waistline 90 cm ( or 80 cm in women ) and vascular invasion had poor overall survival than that without these variables ( p=0.032 , p=0.017 , p=0.009 ) .
the other variables such as sex , afp level , and blood loss were not the significant prognostic factors of overall survival .
on multivariate analysis , however , only vascular invasion and waistline were significantly associated with overall survival ( p=0.031 , p=0.039 ) .
the other variables , including bmi , were not independent prognostic factors of overall survival on multivariate analysis ( table 3 ) .
the overall survival curves of hcc patients according to the bmi are shown in figure 1 .
the 1- , 3- , and 5-year overall survival rates of group a were 95% , 81% , and 16% , respectively .
the 1- , 3- , and 5-year disease - free survival rates of these patients were 78% , 38% and 4% , respectively ( figure 1 ) .
however , there was no significant difference between the 2 groups in disease - free survival ( p=0.235 ) .
the overall and disease - free survival curves of hcc patients affected by waistline were shown in figure 2 .
the 1- , 3- , and 5-year overall survival rates of group c were 97% , 88% , respectively , and 15% compared to 96% , 68% , 15% , respectively , in group d. the 1- , 3- , and 5-year disease - free survival rates of group c were 84% , 40% and 6% , respectively .
group c had significant better overall survival and disease - free survival than group d ( p=0.028 , p=0.048 ) .
there are many reports about the relationship between bmi , the size of waistline , and cancer risk [ 714 ] .
research conducted by the cancer council of victoria , australia shows that a waist measurement of over 100 cm for men and over 85 cm for women can significantly increase the risk of cancer including breast , bowel , and aggressive prostate cancer .
however , there were few reports about the relationship between bmi , waistline , and hcc .
the high hcc rates in china are largely due to the prevalence of chronic hepatitis b virus infection . however , with the increase in prevalence of obesity , nafld , which can progress to cirrhosis and subsequently to the development of hcc , is now recognized as one of the most common liver diseases in china . although many reports had affirmed that patient with higher bmi tend to show a higher incidence of liver cirrhosis , there are few reports about the relationship between the bmi and the surgical outcome of hepatectomy for hcc [ 1517 ] . regarding the relationship between bmi , waistline , and obesity , we hypothesized that waistline might be related to surgical outcome of hepatectomy for hcc , as well . in this study , there were no significant differences in postoperative complication rate and postoperative death between group a and group b. however , pulmonary infection ( 13.3% ) showed a significant difference between the 2 groups ( p=0.017 ) . the observation that the obese patients had more pulmonary infection after hepatectomy for hcc
can be explained by the fact that obesity can reduce pulmonary function through diminishing exercise capacity and lung volume , and increasing the resistance of breathing .
vascular invasion , waistline , and bmi are the independent prognostic factors for long - term survival .
group c had better overall and disease - free survival than group d , and group a had the better overall survival than group b. this result showed that bmi and waistline are both independent prognostic factors for long - term survival .
waistline may be more important than bmi in predicting the prognosis of hcc after hepatectomy .
obesity , which can lead to nafld and finally progress to cirrhosis , is thought to account for the majority of hcc [ 1821 ] . with the increase in prevalence of obesity ,
we recommend that individuals whose bmi or waistline exceeds normal limits should cultivate a healthy lifestyle , such as eating foods that help to lose weight , regular physical exercise , and getting enough sleep .
in conclusion , overweight and obesity have been shown to be significant predictors of an adverse long - time survival after hepatectomy for hcc .
waistline is more important than bmi in predicting the disease - free survival of hcc after hepatectomy .
 backgroundhepatocellular carcinoma ( hcc ) is one of the most common cancers worldwide especially in china . 
 this article aimed to evaluate the influence of body mass index ( bmi ) and waistline on complications , postoperative death , and long - term survival in patients undergoing surgery for hcc.material/methods136 patients were enrolled and divided into 4 groups : group a , bmi < 25 ; group b , bmi 25 ; group c , waistline < 90 cm in males or waistline < 80 cm in females ; group d , waistline 90 cm in males or waistline 80 cm in females . clinical pathological features and surgical outcomes of these patients 
 were analyzed retrospectively.resultsthere were no significant differences in postoperative complication rate and postoperative death between group a and group b , although pulmonary infection showed a significant difference between 2 groups ( p=0.017 ) . 
 vascular invasion , waistline , and bmi are the independent prognostic factors for long - term survival . 
 the disease - free survival curves after hepatectomy showed no statistically significant difference between group a and group b. group c had the better overall survival than group d , and group a had the better overall survival than group b.conclusionsbmi and waistline are both independent prognostic factors for long - term survival of hcc after hepatectomy . 
 waistline is more important than bmi in predicting the disease - free survival of hcc after hepatectomy . 
Background
Material and Methods
Results
Clinicopathologic features of 136 HCC patients underwent hepatectomy
Intraoperative and postoperative data of 136 patients with HCC
Prognostic factors for HCC after hepatic resection
Long-term survival of HCC patients according to the BMI and waistline
Discussion
Conclusions
Supplementary materials