Comparison of surgical outcomes between post-hepatectomy HCC patients with chronic kidney disease and normal kidney

Abstract

Based on figure from American Association for Cancer Research (2010) & Global Cancer Statistics (2011), Liver cancer (HCC) is the sixth most frequently diagnosed cancer globally and third leading cause of cancer death (Jemal, A. et al., 2011; Jemal, A., Center, M. M., DeSantis, C. et al., 2010). In Hong Kong, Liver Cancer caused 1488 deaths in 2009 in total; it is 2nd and 4th leading killer of cancer death among Hong Kong male and female respectively (Hong Kong Cancer Registry, 2010). However, surgical resection for HCC remains as mainstream treatment modality and extensive studies on post-operative surgical outcomes for different HCC treatment modalities have been published. Nevertheless, the influence of kidney function on surgical outcomes on HCC patient stays novel and it emerges a need to explore on the relation. This study aims to compare the surgical outcomes of post hepatectomy HCC patients between reduced kidney function and normal kidney function in terms of (1) Length of hospital stay, (2) Survival rate, (3) Hospital Mortality and (4) Overall post operative complications. The kidney function can be reflected by the glomerular filtration rate (Thomas, R., Stanley, B. & Datta, S., 2007; Daugirdas, J. T., 2011). The direct measurement of GFR is a complicated and expensive procedure, which is not clinical possible to screen every patient. Thus this study adopted modified Cockcroft- Gault (CG) Formula, one type of creatinine based glomerular filtration rate estimation formulas with normalization to body surface area. Modified CG formula calculate the estimated glomerular filtration rate (eGFR) based on age, body weight, body height, gender and serum creatinine level (Himmelfarb, J. & Sayegh, M. H., 2010; Daugirdas, J. T., 2011; Joanna, Q. H. & Heather A. N., 2011).

The eGFR of 452 HCC patients with major hepatectomy was evaluated and categorized into different kidney function groups according to the chronic kidney disease staging system suggested by K/DOQI, National Kidney Foundation. Hence, the surgical outcomes from different kidney function groups are analyzed and compared. Length of hospital stay was analyzed by Kruskal-Wallis Test. Hospital mortality and incidences of post-op complication are analyzed by Chi-square test. Lastly, the survival rate is analyzed by Kaplan-Meier Log rank test; the result is presented in form of survival curve, then 5-year survival rate of different group of samples are obtained and compared.

Result of the study shows no evidence that patients with chronic kidney disease will have a longer hospital stay and more prone to surgical complications post operatively. However, it is indicated that the hospital mortality is associated with the severity of kidney function reduction and suggested that patients with chronic kidney disease are at higher risk of post-operative death than those with normal kidney. Patient with severe reduction of kidney function should be aware of high foreseeable chance of death after the surgery and special caution need to be taken. Surprisingly, the result revealed that the overall survival improves with the severity of kidney function reduction and the patients with worse kidney function are more likely to have a better survival. Nevertheless, the result on survival rate suspected to be biased by possible confounders and underlying co-morbidities of samples.

In conclusion, eGFR formula is recommended in clinical estimation of kidney function for the patients. Also, it is suggested that HCC patients with reduced kidney function are more susceptible to hospital death after hepatectomy than normal individuals. Thus, cautious consideration and risk analysis before operation is particularly crucial for HCC patient with chronic kidney disease.