Biology and significance of alpha‐fetoprotein in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer‐related deaths globally due, in part, to the majority of patients being diagnosed with intermediate or advanced stage disease. Our increased understanding of the heterogeneous molecular pathogenesis of HCC has led to significant developments in novel targeted therapies. Despite these advances, there remains a high unmet need for new treatment options. HCC is a complex disease with multiple pathogenic mechanisms caused by a variety of risk factors, making it difficult to characterize with a single biomarker. In fact, numerous biomarkers have been studied in HCC, but alpha‐fetoprotein (AFP) remains the most widely used and accepted serum marker since its discovery over 60 years ago. This review summarizes the most relevant studies associated with the regulation of AFP at the gene and protein levels; the pathophysiology of AFP as a pro‐proliferative protein; and the correlation of AFP with molecular HCC subclasses, the vascular endothelial growth factor pathway and angiogenesis. Also described are the historical and current uses of AFP for screening and surveillance, diagnosis, its utility as a prognostic and predictive biomarker and its role as a tumour antigen in HCC. Taken together, these data demonstrate the relevance of AFP for patients with HCC and identify several remaining questions that will benefit from future research.     

Early on-treatment predictions of clinical outcomes using alpha-fetoprotein and des-gamma-carboxy prothrombin responses in patients with advanced hepatocellular carcinoma

Background and Aim: The clinical utility of alpha‐fetoprotein (AFP) and des‐γ‐carboxy prothrombin (DCP) as a predictor of treatment outcome in patients with advanced hepatocellular carcinoma (HCC) receiving hepatic artery infusional chemotherapy (HAIC) or concurrent chemoradiation therapy (CCRT) has been poorly defined. Methods: Between January 2003 and December 2007, we enrolled 127 treatment‐naïve patients who received HAIC (n = 60) or CCRT (n = 67) as an initial treatment modality. An AFP or DCP response was defined as a reduction of more than 20% from the baseline level. Results: AFP responders showed significantly better overall survival (OS) than non‐responders among patients with HAIC (median 17.3 vs 6.4 months, P < 0.001) and with CCRT (median 17.6 vs 8.7 months, P = 0.014). DCP responders in the CCRT group also showed significantly better progression‐free survival (PFS) than non‐responders (median 9.2 vs 3.1 months, P < 0.001). Multivariate Cox regression analyses showed that AFP response was independently predictive of OS in both groups (P = 0.009 in HAIC and P = 0.008 in CCRT) whereas DCP only predicted PFS in patients with CCRT (P = 0.015). Conclusions: Early on‐treatment AFP response was predictive of OS in treatment‐naïve patients with advanced HCC receiving HAIC and CCRT as an initial treatment modality. Furthermore, DCP response was useful for predicting PFS in patients with CCRT.     

不同AFP水平下血清IL-1与肝癌根治术后早期复发和预后的关系

目的研究IL-17在不同AFP水平下的HBV相关肝细胞癌(HCC)中的表达情况以及其与HCC根治术后复发和预后的关系。方法收集新疆医科大学附属肿瘤医院2013年1月-2014年12月收治的HBV相关HCC行根治切除术的连续病例167例,另外选取肝血管瘤患者115例(其中HBV携带者83例)作为对照组。采用ELISA法检测167例HBV相关HCC血清中IL-17表达,采用电化学发光法检测血清AFP浓度,并分析IL-17的表达与不同AFP水平的关联性及其与HBV相关HCC患者根治切除术后复发和生存的关系。计数资料组间比较采用χ2检验,生存分析采用Kaplan-Meier相关性分析、Log-rank检验以及Cox比例风险模型。结果将HBV相关HCC患者以血清AFP水平分为2组,AFP<400 ng/ml组IL-17的阳性表达率为50.9%(58/114),AFP≥400 ng/ml组为34.0%(18/53),2组比较差异有统计学意义(χ~2=8.11,P=0.002)。AFP<400 ng/ml组和AFP≥400 ng/ml组患者术后无瘤生存期(34.1个月vs 13.4个月)、总体生存期(84.2个月vs 57.4个月)、1年内肿瘤复发率(28.9%vs 50.9%)比较差异均有统计学意义(χ~2值分别为10.34、3.13、10.89,P值均<0.05)。Kaplan-Meier分析发现,AFP<400 ng/ml的HBV相关HCC患者,IL-17阳性表达组术后1年复发率高于阴性表达组,无瘤生存期、总生存期均显著低于低表达组(χ2值分别为7.350、3.814、9.744,P值均<0.05)。Cox模型分析结果显示,IL-17阳性表达、血管癌栓、组织分化程度是影响HCC患者预后的相关因素(P值均<0.05)。结论 AFP<400 ng/ml的HBV相关HCC患者中IL-17阳性表达预示着早期复发和预后不良。     

Multicenter prospective analysis of newly diagnosed hepatocellular carcinoma with respect to the percentage of Lens culinaris agglutinin-reactive alpha-fetoprotein

BACKGROUND AND AIM: The Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein (AFP-L3) has been reported to be a highly useful marker for hepatocellular carcinoma (HCC) compared with a conventional serum AFP concentration, which allows earlier detection of HCC compared with using other imaging modalities and predicting prognosis after therapy. A collaborative prospective study involving nine Japanese hospitals was conducted to analyze the relationships between the tumor characteristics of a HCC patient and the percentage of AFP-L3/AFP total at the initial detection. METHODS: Between 1 October 1996 and 30 September 1997, a total of 388 patients with newly diagnosed HCC were registered. RESULTS: The cut-off level of the percentage of AFP-L3 was altered from 15 to 10%. The AFP-L3-positive HCC patients demonstrated the characteristics of having an advanced tumor, such as the number of tumors, maximum diameter, tumor spread, portal vein invasion, tumor stage, and tumor classification. With the conventional cut-off level of 15% of the percentage of AFP-L3, the malignant characteristics were more definite than that of 10%. However, no significant differences of serum AFP concentration were observed for malignant characteristics such as maximum diameter and histopathological grading. CONCLUSION: Serum AFP concentration does not reveal a malignancy of HCC, however, the AFP-L3-positive HCC has biologically malignant characteristics, especially portal vein invasion and lower tumor classification, and is an advanced tumor regardless of small tumor size and lower serum AFP concentration. As AFP-L3 shows the tumor characteristics, its presence should be an important factor in the determination of therapy and prognosis of patients.     

甲胎蛋白阴性的肝细胞肝癌5例临床病理观察

[目的]探讨甲胎蛋白(AFP)阴性的肝细胞肝癌(hepatocellular carcinoma,HCC)的病理形态特点及鉴别诊断。[方法]观察和分析5例HCC的临床和病理组织学特点及免疫组和染色结果。[结果]5例中女2例,男3例,年龄50~69(中位年龄58.8)岁。临床表现病毒性肝炎、肝硬化及肝部占位并血清AFP检测值阴性。光镜下癌细胞密度增加,肝板细胞层数增多,排列呈条索状、小梁状、实性巢团状,小梁周围为扩张不规则的肝窦,癌细胞大小不一,异型性明显,细胞胞浆嗜酸核分裂像易见。免疫组化:5例AFP、CD10、CK7、CK20、GCDFP15、ER、PR、CK19、CDX-2、CEA均为阴性,CD34、VIllin均为阳性,Hep pax1 3例阳性、1例阴性、1例点灶阳性。[结论]APF阴性的HCC是少见病理类型,结合其临床症状、部位、组织病理特点和免疫组化标记可确定诊断。     

Des-gamma-carboxyprothrombin, alpha-fetoprotein and AFP-L3 in patients with chronic hepatitis, cirrhosis and hepatocellular carcinoma

Background and Aim: Hepatocellular carcinoma (HCC) is a common complication in patients with chronic viral hepatitis. Detection of HCC at an early stage is critical for a favorable clinical outcome. The study aim was to: (i) compare the levels of des‐γ‐carboxyprothrombin (DCP), α‐fetoprotein (AFP) and AFP‐L3 in HCC patients and in chronic viral hepatitis patients without HCC; (ii) define the level of each tumor marker with the best sensitivity and specificity for HCC diagnosis; and (iii) to correlate the levels of these markers with respect to size and tumor burden. Methods: Two hundred and forty patients with either hepatitis B virus (HBV) or hepatitis C virus (HCV) infection were studied. These included 144 with HCC, 47 with chronic hepatitis (fibrosis stage I–III on liver biopsy) and 49 with cirrhosis. Results: Levels of DCP, AFP and AFP L‐3 were significantly higher in patients with HCC than in those without HCC (P ≤ 0.0001). Receiver–operating curves (ROC) indicated that the cut‐off value with the best sensitivity and specificity for each test was ≥84 mAU/mL for DCP, ≥25 ng/mL for AFP and ≥10% for AFP‐L3. The sensitivity, specificity and positive predictive value (PPV) for DCP was 87%, 85% and 86.8%, for AFP 69%, 87% and 69.8%, and for AFP‐L3 56%, 90% and 56.1%, respectively. DCP levels were below the ROC cut‐off in all patients without HCC. In patients with single lesions, there was a direct correlation of DCP to tumor size. High levels of AFP correlated with diffuse type of HCC. All three markers were significantly elevated in the presence of metastatic HCC. No advantage was observed by combining two or three markers for HCC diagnosis. Conclusion: DCP had the highest sensitivity and PPV for HCC diagnosis, had a direct correlation with tumor size, and was not elevated in any patients without HCC. DCP should be used as the main serum test for HCC detection.     

Hepatocellular carcinoma in patients with chronic hepatitis C and cirrhosis in Denmark: A nationwide cohort study

Cirrhosis in patients with chronic hepatitis C increases the risk of hepatocellular carcinoma (HCC ), and surveillance with ultrasound (US ) and alpha‐fetoprotein (AFP ) is recommended. This study aimed to estimate changes in the HCC incidence rate (IR ) over time, HCC stage and prognosis, and AFP and US performed in patients with hepatitis C and cirrhosis. Eligible patients were identified in the Danish Database for Hepatitis B and C, and data from national health registries and patient charts were obtained. Tumour stage was based on Barcelona‐Clinic Liver Cancer stage, TNM classification and size and number of lesions combined into stages 0‐3. We included 1075 patients with hepatitis C and cirrhosis, free of HCC and liver transplant at baseline. During 4988 person years (PY ), 115 HCC cases were diagnosed. The HCC incidence rate increased from 0.8/100 PY [CI 95% 0.4‐1.5] in 2002‐2003 to 2.9/100 PY [2.4‐3.4] in 2012‐2013. One‐year cumulative incidence of at least one AFP or US was 53% among all patients. The positive predictive value of an AFP  ≥ 20 ng mL^?1 was 17%. Twenty‐three (21%) patients were diagnosed with early‐stage HCC (stage 0/1) and 84 (79%) with late stage. Median survival after HCC for early‐stage HCC disease was 30.1 months and 7.4 months for advanced HCC (stage 2/3). The incidence rate of HCC increased over time among patients with hepatitis C and cirrhosis in Denmark. Application of AFP and US was suboptimal, and most patients were diagnosed with advanced HCC with a poor prognosis.     

Low alpha‐fetoprotein hepatocellular carcinoma

Background and Aim: A large proportion of hepatocellular carcinoma (HCC) patients do not secrete elevated levels of the tumor marker alpha‐fetoprotein (AFP). There is little published guide to prognostic features of this patient subset. Methods: We interrogated a large HCC database in which all patients had been followed until death, to examine which features might be prognostically useful. Results: We found 413 biopsy‐proven unresectable HCC patients with low serum AFP values. Serum gamma glutamyl transpeptidase (GGTP) levels were one of the most significant factors for survival. This dichotomization into low and high GGTP levels separated the patients into distinctive survival ranges. Patients with GGTP levels < 110 U/100 mL and small tumors had longest survival > 795 days. Patients with GGTP ≥ 110 U/mL and large tumors with the presence of portal vein thrombosis had the shortest survival range of 300–560 days. Conclusions: Serum levels of the onco‐fetal protein GGTP represent a useful prognostic parameter in HCC patients with low AFP levels.     

DR-70 immunoassay for the surveillance of hepatocellular carcinoma

Background and Aim: Although alpha‐fetoprotein (AFP) is a widely used serological marker for hepatocellular carcinoma (HCC), its utility is limited due to its unsatisfactory sensitivity. Meanwhile, a newly developed immunoassay—DR‐70—has been reported to have a good sensitivity for HCC in a small‐scale study. The aim of this study was to determine the clinical value of DR‐70 for the surveillance of HCC. Methods: Serum levels of DR‐70 and AFP were measured in 103 patients with HCC, 50 healthy volunteers, and 33 patients with chronic liver disease. In addition, we investigated the prognostic value of DR‐70 in patients with HCC correlating with the clinical staging—Cancer of the Liver Italian Program (CLIP) score and Barcelona Clinic Liver Cancer (BCLC) classification. Results: Based on the receiver operating characteristic curve with area under the curve of 0.836, the DR‐70 cut‐off value for detecting HCC was determined to be 0.75 µg/mL. DR‐70 provided a sensitivity of 81.6% and a specificity of 77.1%, and correlated well with the CLIP score and BCLC classification. The combination of DR‐70 and AFP increased the sensitivity to 91.2%. The prognosis for patients with HCC with DR‐70 level > 0.75 µg/mL was worse than that for those with DR‐70 ≤ 0.75 µg/mL. Among the patients with early stage HCC (CLIP score 0–2), DR‐70 > 0.75 µg/mL independently predicted a poor survival. Conclusions: DR‐70 immunoassay is complementary to AFP for the detection of HCC and has a good correlation with clinical staging and prognosis.     

Clinical utility of serum fucosylated hemopexin in Japanese patients with hepatocellular carcinoma

Aim: Hepatocellular carcinoma (HCC) is a common clinical problem all over the world. Fucosylated hemopexin (Fuc-Hpx) is a newly reported glycoprotein for the diagnosis of HCC, however, its clinical implications are unclear. The aim of this study was to elucidate the clinical utility of Fuc-Hpx in Japanese patients with HCC. Methods: The sera from 331 HCC patients, 45 with liver cirrhosis (LC), 85 with chronic hepatitis (CH) and 22 healthy people were examined for the expression of Fuc-Hpx; the level was compared with clinical parameters as well as hemopexin (Hpx) expression. The expressions of Fuc-Hpx in 12 HCC tissues and corresponding adjacent non-cancerous liver tissues were also examined. Results: No correlation was observed between Hpx and Fuc-Hpx level. The median Fuc-Hpx levels in healthy people and CH, LC and HCC patients were 3.8, 3.7, 6.1 and 7.6 AU/mL, respectively (CH vs LC, P = 0.002; CH vs HCC, P < 0.001; LC vs HCC, P = 0.02). Multivariate analysis revealed that low albumin, low prothrombin time and the presence of HCC were significantly correlated with high Fuc-Hpx (P = 0.013, =0.001 and <0.001, respectively). Among the HCC patients, albumin was correlated with high Fuc-Hpx; however, none of the tumor factors, such as tumor size, tumor number and tumor stage, was correlated with Fuc-Hpx level. The expression of Fuc-Hpx in cancer tissue was not different from that in non-cancerous tissue. Conclusion: Fuc-Hpx is a valuable biomarker for HCC but it might be a marker for hypercarcinogenic liver rather than a marker for tumor-bearing liver.     

Relationship between Lens culinaris agglutinin-reactive alpha-fetoprotein and pathologic features of hepatocellular carcinoma.

AIM: We investigated pathological features of Lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3)-positive hepatocellular carcinoma (HCC) in order to seek a pathological basis of poor prognosis of HCC patients with elevated AFP-L3. METHODS: A total of 111 patients with HCC < or =5 cm in diameter who underwent hepatic resection were studied. Serum AFP-L3 concentration was measured within a month prior to surgery by lectin-affinity electrophoresis coupled with antibody-affinity blotting, and expressed as AFP-L3 percentage of total AFP. AFP-L3 of 10% or higher was judged to be positive. Pathologic features of resected HCC specimens were evaluated and classified concerning growth pattern (expansive or infiltrative growth), capsule formation, capsule infiltration, septal formation, portal vein invasion, hepatic vein invasion, bile duct invasion, and intrahepatic metastasis. These macroscopic and microscopic findings were compared between AFP-L3-positive and negative HCC specimens. RESULTS: Thirty-three (29.7%) were positive for AFP-L3. The prevalence of HCC with infiltrative growth, with capsule infiltration, with septum formation, with portal vein invasion, and with hepatic vein invasion was significantly higher in AFP-L3-positive group (P=0.0121, 0.0290, 0.0442, 0.0314, and 0.0433, respectively). These pathologic features reportedly indicate the progression of the tumor. CONCLUSIONS: AFP-L3-positive HCC had several pathologic features of progressed state of HCC, which accounted for the AFP-L3 as an indicator of poor prognosis of HCC.     

HBsAg及AFP在肝细胞癌组织中的表达及其相关性

目的进一步探讨HBV感染在肝细胞癌（HCC）发病中的作用。方法选择40份HCC、癌旁肝组织标本及6份正常肝组织标本,用免疫组化SP法检测其HBsAg与甲胎蛋白（AFP）表达。结果正常肝组织中HBsAg及AFP表达均为阴性;HCC和癌旁肝组织中HBsAg及AFP表达阳性率分别为70%、90%（P〈0.05）,HCC和癌旁肝组织AFP表达阳性率分别为87.5%、82.5%（P〉0.05）;HCC及癌旁肝组织中HBsAg阳性者AFP表达阳性率明显高于HBsAg阴性者（P〈0.05）。结论 HBV感染可能通过诱发肝细胞产生AFP参与HCC发病,具体机制有待进一步研究。     

Effect of antiviral treatment on alfa‐fetoprotein levels in HBV‐related cirrhotic patients: early detection of hepatocellular carcinoma

Summary. Alpha‐fetoprotein (AFP) is a marker of the presence of hepatocellular carcinoma (HCC), but is also elevated in advanced chronic hepatitis B. The detection and usage of AFP tests need to be improved. A cohort of 101 patients with advanced chronic hepatitis B and elevated AFP values was treated with entecavir (ETV) or peginterferon‐α2a. ETV was more effective in reducing AFP levels; mean time to AFP normalization was 11.9 weeks after ETV treatment initiation vs 22.3 weeks in peginterferon treated patients (P = 0.000). An additional cohort of 93 hepatitis B virus (HBV) cirrhotic patients with elevated AFP were treated with ETV prospectively and maintained under intensive surveillance. HCC developed in 16 (17.2%) patients in whom the strongest independent predictor was a continued AFP rise in spite of ongoing treatment. In this context, nodules of sizes 10–14 mm and 15–20 mm were detected in 40% of patients each. In conclusion, HBV cirrhotic patients with rising AFP levels were at very high risk of HCC development. Early detection of minute lesions may be possible by monitoring AFP levels, whilst patients are on treatment in conjunction with enhanced computed tomography examination.     

Reappraisal of the diagnostic value of alpha‐fetoprotein for surveillance of HBV‐related hepatocellular carcinoma in the era of antiviral therapy

This study was designed to explore if antiviral treatment influences the performance of serum alpha‐fetoprotein (AFP) for hepatocellular carcinoma (HCC) among the high‐risk chronic HBV‐infected patients. A total of 5936 patients who had evidence of chronic HBV infection were enrolled from four independent centres in this retrospective study, including 1721 chronic hepatitis B (CHB), 2286 liver cirrhosis (LC), 798 HCC within Milan criteria and 1131 HCC beyond Milan criteria patients. Stratified by whether they received treatment or not, the patients were further divided into antiviral and non‐antiviral groups. Then, the performance of AFP for discriminating HCC was evaluated. Patients receiving antivirals had significantly lower median levels of AFP compared with the non‐antiviral patients (P < .001), and there were significantly less patients with abnormal AFP levels in antiviral groups (P < .001). Antiviral therapy improved the AUROCs of AFP for discriminating HCC within Milan criteria. When setting the cut‐off values at 20 ng/mL and 100 ng/mL as surveillance and confirmatory tests respectively for HCC among patients receiving antiviral treatment, AFP exhibited a significantly higher sensitivity than those of 200 ng/mL and 400 ng/mL, which are currently recommended by some guidelines, without compromising specificity. Further analysis in antiviral patients revealed that serum AFP had better performance for discriminating HCC within Milan criteria in ALT ≤ 1ULN patients than that in ALT > 1ULN patients. In conclusion, in the era of antiviral therapy, serum AFP's surveillance performance was substantially improved for HCC within Milan criteria among the high‐risk population of CHB and LC patients.     

Comparison of clinicopathological features of patients with hepatocellular carcinoma seropositive for alpha-fetoprotein alone and those seropositive for des-gamma-carboxy prothrombin alone

BACKGROUND: There has been no comparative study of the clinicopathological features of HCC patients who are seropositive for alpha-fetoprotein (AFP) alone and those who are seropositive for des-gamma-carboxy prothrombin (DCP) alone. The authors, thus, performed this comparative study. METHODS: The clinicopathological features of patients with solitary hepatocellular carcinoma (HCC), who underwent a hepatectomy were compared among the four below groups according to the seropositivity of AFP and DCP: group A, seronegative for both AFP below 20 ng/mL and DCP below 40 mAU/mL; group B, seropositive for AFP above 100 ng/mL and seronegative for DCP; group C, seronegative for AFP and seropositive for DCP above 100 mAU/mL; and group D, seropositive for both AFP and DCP. RESULTS: Group B patients showed a higher incidence of HCC with an indistinct margin, and a somewhat higher incidence of small HCC less than 2 cm in greatest dimension compared with group C patients. By contrast, group C patients had a higher frequency of HCC with a distinct margin compared with that of an indistinct margin, large tumors more than 3 cm compared with that of small tumors less than 2 cm, and a somewhat higher frequency of moderately to poorly differentiated HCC compared with that of well-differentiated HCC. Our HCC cases showed advanced clinicopathological features in the order of group C, group B and group A. Groups C and D patients showed similar characteristics. CONCLUSIONS: Hepatocellular carcinoma patients who were seropositive for AFP alone demonstrated clinicopathological features of less advanced HCC compared with those who were seropositive for DCP alone.