You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Diagnostic Utility of Interleukin-6 (IL-6) for Primary Bile Duct Cancer and Changes in Serum IL-6 Levels Following Photodynamic Therapy
Abstract 1:
OBJECTIVES : Difficult diagnoses and a lack of effective therapy complicate biliary tract malignancies .  Interleukin-6 ( IL-6 ) is a human bile duct epithelium growth factor correlated with tumor burden . We evaluated the usefulness of serum IL-6 in the diagnosis of primary BDC and measured changes in serum IL-6 levels following photodynamic therapy ( PDT ) . METHODS : We prospect ively measured serum IL-6 levels in patients with BDC ( N = 26 : 14 patients treated with PDT , 12 with biliary drainage alone ) , hepatocelluar carcinoma ( HCC , N = 26 ) , and healthy adults ( N = 23 ) .  Serum IL-6 levels were measured by an enzyme-linked immunosorbent assay . Patients with clinical conditions known to increase IL-6 levels were excluded . RESULTS : IL-6 was detected in all patients with BDC and HCC , and in 6 of 23 healthy adults .  Median and mean levels of IL-6 were higher in patients with BDC than in both other groups ( P < 0.001 ) . Using a 25.8 pg/mL cutoff , IL-6 provided a diagnostic sensitivity of 73 % and a specificity of 92 % ; positive and negative predictive values were 83 % and 87 % , respectively . Serum levels of IL-6 were correlated with tumor burden in BDC patients . One month after treatment of BDC with PDT , the mean IL-6 level decreased significantly from 282.1 ± 121.8 to 38.2 ± 9.9 pg/mL ( P = 0.008 ) . CONCLUSIONS : Serum IL-6 concentration is a useful addition to the available tests for the differential diagnosis of BDC , and serves as a marker for monitoring the response to treatment of BDC with PDT


Title 2:
Evaluation of interleukin-6, interleukin-10 and human hepatocyte growth factor as tumor markers for hepatocellular carcinoma.
Abstract 2:
AIM Serum alpha-fetoprotein  ( AFP ) is the most important tumor marker for hepatocellular carcinoma ( HCC ) . Previous reports indicated that HCC was also associated with increased levels of interleukin (IL)-6 , IL-10 and hepatocyte growth factor ( HGF ) . This study investigated the role of these cytokines as tumor markers for HCC . METHOD A total of 128 adults were prospect ively enrolled and categorized into four groups : normal subjects ( n=29 ) , chronic hepatitis B or C ( n=50 ) , non-HCC tumors ( n=23 ) and HCC ( n=26 ) .  Serum AFP , IL-6 , IL-10 and HGF levels were determined in all subjects . RESULTS The expression of IL-6 or IL-10 ( > or =3 pg/ml ) , or high level of HGF ( > 1000 pg/ml ) or AFP ( > 20 ng/ml ) was observed in only 0 - 3 % of normal subjects . Patients with HCC more frequently had higher IL-6 and IL-10 levels ( p<0.05 ) , whereas HGF levels in HCC patients were not significantly elevated compared to patients with chronic hepatitis or non-HCC tumors . Among patients with low ( < 20 ng/ml ) AFP level , IL-6 or IL-10 expression was significantly associated with the existence of HCC ( p<0.05 ) . Patients with large ( > 5 cm ) HCC more often had increased IL-6 , IL-10 or AFP levels ( p values all < 0.05 ) . CONCLUSIONS Serum levels of IL-6 and IL-10 are frequently elevated in patients with HCC but not in benign liver disease or non-HCC tumors . IL-6 and IL-10 may help identify a subset of HCC patients with low AFP level , and may serve as complementary tumor markers in these patients


Title 3:
Assessment of the role of interleukin-6 in diagnosis of hepatocellular carcinoma.
Abstract 3:
Interleukin-6  ( IL-6 )  is a promising tumor marker for hepatocellular carcinoma ; HCC . IL-6 may help to identify a subset of HCC patients with low alpha-fetoprotein ( AFP ) level , and may serve as complementary tumor marker , however , this has to be clarified . This study assesses the value of measuring serum level of interleukin-6 in patients with chronic liver disease and HCC , and evaluates its sensitivity and specificity in comparison to AFP in early diagnosis of HCC . Seventy five patients with chronic liver disease ( CLD ) with or without HCC and 25 healthy controls were included . Patients were divided into Group I : 25 patients with CLD but no evidence of HCC . Group II : 25 patients with HCC on top of post-viral hepatitic with elevation in AFP ( > 200 ng ) ; and Group III : 25 patients with HCC on top of post-viral hepatitic but without elevation in AFP ( < 200 ng ) . Analysis of the mean serum IL-6 levels revealed a statistically significant difference between all groups ( P < 0.01 ) . A significant positive correlation was found between mean levels of IL- 6 & AFP in HCC ( P < 0.05 ) , the mean IL-6 levels in patients with Child classification C was higher than in those with Child A and B.After adjustment using multiple logistic regressions , only loss of weight and AFP were found to be significantly associated with HCC ( P < 0.05 ) . It is concluded that the diagnostic value of IL-6 increased when it is associated with AFP measurement . Combining the two markers can provide a new perspective in the diagnosis of HCC
Conclusions The elevated IL-6 levels in HCC patients compared with hepatitis and cirrhosis patients and healthy controls may show a significant association of this cytokine with increased risk of HCC and its potential as a diagnostic marker for HCC in future diagnostic and therapeutic strategies