MOJ often occurs in the advanced stage of locally invasive, malignant neoplasms, which directly invade or compress the biliary tree either by the primary tumor or via nodal metastases. The resultant obstructive jaundice further leads to the failure of liver function. The aim of our study was to investigate the prognostic factors of MOJ and the effect of drainage and follow-up treatment on survival time. Our results demonstrated: 1). The median OS in the functionally successful group was statistically significantly greater than in the non-functionally successful group (243 vs 95 days); 2). the median survival time of the group able to undergo follow-up treatment group was also greater than the no follow-up treatment group (356 vs 100 days); 3). anemia, increased serum bilirubin before and persistently after PTBD tumor size, and ALBI grade were poor prognostic factors; and 4. patients with a proportional decrease in total serum bilirubin level after drainage of > 44.4% had a better clinical prognosis. The ROC curve and AUC showed the predictive ability of a proportional decreased in total serum bilirubin. Indeed, an AUC of 0.768 could predict mortality in 77% of patients with MOJ.
In our study, while the technical success rate was 96.7%, which was similar to some previous findings, the clinical success rate of only 50.6% as defined by a decrease to normal or a > 50% decrease was less than that observed in the study of Zhang et al (76.5%) [10]. In the Zhang study, however, clinical success was defined as a 20% decrease in serum bilirubin, which was considerably less than our definition (50%). Moreover, our relatively lower clinical success rate may be explained by the baseline bilirubin levels in our patients which were relatively greater and in our study more patients had advanced cancer, most of whom had hilar invasion, which leads to a high failure rate of biliary drainage.
Univariate statistical analysis revealed the significant variables responsible for poor survival, including anemia, poor liver function, and tumor-related factors. The ALBI grade was statistically significant, with a higher grade being indicative of a worse prognosis. In another study of patients with hepatocellular cancer, the Child–Pugh class was included and showed that Child–Pugh C liver function was a factor affecting survival [3]; however, there was no comparison of the effect of two liver function classifications on survival time in obstructive jaundice. In our study, multivariate statistics showed that after biliary drainage, the resultant total bilirubin was an independent prognostic factor for poor survival despite the pre-drainage serum bilirubin levels were generally not associated with clinical success similar to the findings of a previous study [10].
Our study and several others have demonstrated that successful drainage of obstructive jaundice followed by the ability to provide local therapy, such as TACE, chemotherapy, radiotherapy, or radiofrequency or systemic chemotherapy significantly prolongs survival time and improves the quality of life of patients [2, 11, 12, 13]. The results of our multivariate analysis showed that functional clinical success and post-drainage treatment were independent factors of better survival and improved patient outcomes in these patients with advanced tumors. The overall median survival time in our study was 135 days, which was slightly greater than the intervals of 79–104 days reported in previous studies [2, 11, 13], but OS varies with the patient population studied. What is important is that the median survival time of 243 days in the patients with a functionally successful drainage was significantly greater than in the non-successful group (95 d). In the functionally successful group, patients who received chemotherapy, radiofrequency ablation, or TACE had a greater survival rate than those in the group with no follow-up treatment. Although other studies of patients with colorectal cancer [14] have not shown a relationship between biliary drainage and survival, such differing results might be related to different prognostic factors and patient characteristics. However, our study demonstrated that survival was closely associated with functionally successful drainage and follow-up treatment. However, different results might be generated in different studies due to different prognostic factors and patient characteristics. We maintain that the proportional decrease in post drainage total serum bilirubin level is an important prognostic factor, because the ROC curve and AUC showed its predictive ability.
As in multiple other studies, common complications of biliary drainage include cholangitis, hemorrhage, pancreatitis, pleural injury, biliary-heart reflex, and displacement of the biliary drainage tube after PTBD. Among them, infection and hemorrhage are the main causes of PTBD-related death. In our study, although postoperative infection occurred in 28% of patients, after antibiotic treatment, body temperature and leukocytes returned to normal. No patient died due to infection, and the 30-day mortality rate was 5%, compared to 2–19.8% in previous studies [15.16].
Our study has several limitations that warrant discussion. First, this study was retrospective and included multiple different sites of the primary neoplasm, with the resultant expected heterogeneity in the response to treatment. Second, no subgroup analysis of stenting alone was performed due to the small number of stent-related cases. Third, we only evaluated the outcomes of PTBD patients and did not compare those patients who underwent the somewhat less invasive means of internal biliary drainage like ERCP/endoprosthesis. Fourth, because clinical symptoms such as itching, weakness, nausea, and nutritional status were excluded from our study, we did not analyze the patients’ quality of life. Fifth, no data on general PS were analyzed in this study, which may lead to selection bias between groups. This imbalance of clinical background may have influenced the difference in survival between patients who received successful drainage and those whose PTBD and post-drainage further treatment was unsuccessful. Therefore, randomized controlled trials are needed to support our findings, and possibly focused on specific patient groups like hepatic cancer, cholangiocarcinoma, periampullary and pancreatic cancers, and metastases from colon cancer.
In conclusion, PTBD can be used successfully in selected patients with MOJ to prolong the survival time of patients. Indeed, palliative care after biliary drainage can prolong patients’ survival and improve their quality of life. The proportional decrease in total serum bilirubin level of > 44.4% can be used to expect a greater survival advantage in patients with MOJ.