Primary liver cancer is the sixth most common cancer and the second leading cause of cancer death worldwide, which poses a huge economic and disease burden worldwide due to its high morbidity and mortality rates (1, 2). China is the country with the highest hepatocellular carcinoma (HCC) occurrence and the overall incidence of HCC is expected to continue to climb (3). HCC occurs most often in the setting of chronic liver inflammation and is mainly induced by hepatitis B virus (HBV) infection (4), which is a key risk factor for liver cirrhosis and HCC, capable of increasing the risk of HCC approximately 20-fold (5–7). For early HCC, surgical resection, liver transplantation, and ablation are recommended treatments. Studies have shown that ablation has similar five-survival rates compared to surgical treatment, and fewer complications than surgery (8, 9). However, the recurrence rate after ablation remains high, with a five-year recurrence rate of 50-70% (10). Transcatheter arterial chemoembolization (TACE) is the only guideline-recommended global standard of care for intermediate-stage HCC, and the median progression-free survival time (mPFS) is only 5 months (11). Therefore, diagnosis and treatment of HCC is an increasingly important public health problem.

The first serologic marker of HBV infection is Hepatitis B surface antigen (HBsAg), which can be detected from 2 to 12 weeks after infection with HBV (12). HBsAg clearance, which is currently regarded as the functional cure of chronic hepatitis (CHB), is associated with improved long-term outcomes and reduced risk of complications (13, 14). The decline in HBsAg during antiviral therapy is relatively slow, and the seroclearance rate is faster at low serum HBsAg expression (<1000U/L) (15, 16). Previous studies revealed that high serum levels of HBsAg increase the risk of developing HCC and have a worse prognosis for patients who have already developed HCC (17). Nevertheless, the prognostic impact of serum HBsAg levels in patients after TACE sequential ablation therapy needs to be further confirmed.

HBV-HCC prognosis is linked to several factors, including tumor burden, AFP, disease stage, ALBI, and NLR (18, 19), and there are also nomograms about HBV-HCC (20–22). However, no nomogram for HCC patients with high HBsAg expression after local treatment has been available to our knowledge. We compared the effects of high levels of HBsAg (≥1000U/L) and low levels of HBsAg (<1000U/L) in HCC patients undergoing TACE and sequential ablation and utilized propensity score matching to minimize selection bias. In addition, we created a nomogram to predict the prognosis of HCC patients with high levels of HBsAg after local treatment to more accurately guide the clinical decision.

A total of 1008 HBV-HCC patients from Beijing Youan Hospital and Beijing Ditan Hospital were screened between January 1, 2014, to December 31, 2021, including 334 patients with low HBsAg levels and 674 patients with high HBsAg levels. After PSM, 293 patients were included in each group ( Figure 1 ). The high levels of HBsAg groups were divided into the training cohort (N=385), internal validation cohort (N=168), and external validation cohort (N=121). The last follow-up until July 1, 2023, and the median follow-up time was 4.05 years (25~75th percentiles, 2.68~7.05 years).

Before PSM, baseline data showed that compared to the low HBsAg level group, the high HBsAg level group had a younger age (55.9 ± 9.03 VS. 58.3 ± 8.34, P<0.001), lower levels of TBIL (18.64 ± 9.42 VS. 20.84 ± 11.37, P=0.002), and shorter TT (15.77 ± 2.12VS. 15.95 ± 2.39, P=0.008). After PSM, all demographic and clinicopathologic data were well balanced between the two groups ( Table 1 ).

The internal validation cohort and the external validation cohort had similar baseline characteristics to the training cohort. In the three cohorts, the majority of the patients were male (81.0%VS. 77.4%VS. 76.9%, p=0.466), and the average age was over 50 years(56.1 ± 9.10 VS. 56.6 ± 8.46 VS. 57.9 ± 8.57, P=0.466). Most patients were Child-Pugh A (76.9%VS. 80.4% VS., P=0.427), suggesting that the patients had good liver function. BCLC A had the highest percentage of patients (51.7% VS. 55.4% VS. 71.7%, P=0.182). Regarding tumor characteristics, most tumors were solitary (70.6% vs.71.4% VS. 67.8%, P=0.780) and tumor size was less than 3cm (70.6% vs. 69.0% VS. 67.8%, P=0.150) ( Table 2 ).

HCC is one of the most common malignant tumors in the world. In China, the major etiology of the HCC is the HBV infection, which can promote the development and metastasis of the HCC (10, 24, 25). With the use of 1:1 PSM, our study found that the high level of HBsAg had a higher risk of recurrence than the low level of HBsAg. Consequently, our study is the first to focus on the high level of HBsAg patients who underwent TACE combined ablation to develop and validate a nomogram, which will hopefully predict the recurrence in H-HBsAg patients (High level of HBsAg). At present, there is a lack of a recurrence prediction model for H-HBsAg. We simultaneously created a nomogram by Lasso-Cox regression to accurately predict the prognosis of H-HBsAg patients.

The nomogram contains seven factors to produce the probability of an individual-specific clinical event, including age, tumor size, BCLC stage, globulin, GGT, and bile acid. The scores of the nomogram were obtained by drawing a vertical line at the location of the corresponding total score so that it intersected the three lines predicting the risk of recurrence, and the values shown at the intersection were predicted RFS at 1, 3, and 5 years. The C-index and AUCs of the training cohort and validation cohorts were similar, demonstrating adequate discrimination ability. The calibration curves presented the good prediction performance of the nomogram. Moreover, the nomogram indicated reliable clinical applicability by DCA curves. Patients were divided into two different risk groups according to the nomogram, and RFS was clearly different(P<0.001), which illustrated that our nomogram had a better ability to distinguish H-HBsAg patients to determine the risk of relapse after ablation therapy.

The number and size of tumors suggested strong tumor aggressiveness and poor prognosis of HCC, which was currently uncontroversial and needed not to be described here. Liver weight and portal blood flow velocity are reduced in the elderly, resulting in less reparability of the young body. Elderly people have lower immunity and faster tumor progression after treatment, leading to higher recurrence rates and worse prognosis (26, 27). At present, the BCLC system is regarded as an optimal staging system for tumor stage, treatment regimens, and expected survival. The expected survival rate is 50-70% for patients who are BCLC A at 5 years (28, 29). When we combined BCLC with other independent prognostic factors, the predictive value for prognosis could improve. GGT may be involved in the balance of oxidant and anti-oxidation, leading to sustained oxidative stress in tumor cells, which can contribute to the process of cancer (30, 31). Various proinflammatory proteins, including immunoglobulins, C-reactive protein, α2 macroglobulin, and fibrinogen are globulins (32, 33). Since human immunoglobulins are mainly metabolized by the liver, patients with severe hepatic dysfunction have a reduced ability to clear immunoglobulins, causing hyperglobulinemia (34, 35). Bile acid synthesis occurs in liver cells and is the end product of cholesterol metabolism (36). The Systemic homeostasis of bile acid mainly depends on its enterohepatic circulation process, which is of great significance for nutrient absorption and distribution, metabolic regulation, and homeostasis (37). Bile acid metabolism is implicated in tumor progression and hydrophobic bile acids are promoters of HCC (38, 39). Besides, reduced Farnesoid X (FXR) receptor signaling during hepatic inflammation induces to decrease in bile acid transporter proteins, resulting in elevated bile acids and persistent hepatic inflammation, which promote the development of HCC (40, 41).

The presence of HBsAg is a serologic marker of HBV infection and is used in clinical diagnosis (42, 43). HBsAg appears 1-2 weeks after exposure to HBV and precedes the onset of clinical symptoms and other serologic biochemical indicators of infection. There are still 257 million carriers of HBsAg despite the availability of antiviral therapeutics (44, 45). Many studies showed that the spontaneous HBsAg seroconversion rate was 1% and the presence of persistent HBsAg was associated with a high risk of HCC and a worse prognosis (46, 47). Previous studies by our team have also reported that the prognosis of HCC patients with negative HBsAg expression was better than that with positive HBsAg expression (48). In our study, we investigated the role of HBsAg levels in the recurrence of HCC after local treatment and used PSM to reduce bias. The results revealed that HBV-HCC patients with high HBsAg levels have worse prognosis than those with low HBsAg levels.

In the BCLC Guideline, TACE is recommended for BCLC intermediate stage B HCC. For early-stage HCC, TACE can mark the tumor and achieve tumor downstaging, thereby declining the time and increasing the success rate of ablation (49). Foreign and domestic studies have suggested that combination therapy by TACE and ablation improved overall and progression-free survival compared with TACE alone (50, 51). Unlike the conventional univariate analysis, the LASSO regression that we used aimed to select variables for Cox regression to avoid overfitting. Also, the nomogram can be validated by both internal and external validation because our study was a multicenter retrospective study. Simultaneous examination of comprehensive patient features covering demographics, liver function, tumor load, tumor markers, and inflammatory markers was a major strength of our study. The consists of our nomogram are simple and easy to obtain so that the clinicians are able to evaluate the patient’s condition in a timely and effective manner.

Several limitations of our study should be addressed. The first one of them is the retrospective nature and it is necessary to strengthen the conclusions by further validations in large prospective studies. Because as a retrospective study, there is inevitable selection bias. Although internal and external validations were conducted by a larger multicenter sample, external validations from other centers are still required in the future. Besides, the patients included in our study all received TACE combined with ablation. Whether the nomogram would be suitable for other treatments such as surgery and liver transplantation requires further investigation. Lastly, the study was conducted only in China, where hepatitis B virus is the principal cause of HCC. Thus, generalizing to other populations in which HBV is not a major causative factor for HCC must be carried out with caution. Nevertheless, we used up to eight years of follow-up to create an accurate and reliable nomogram to better guide clinical practice for this group of HCC patients with high levels of HBsAg. In general, high-risk patients needed more frequent clinical surveillance and appropriate interventions to prevent recurrence and progression.

In summary, high levels of HBsAg were associated with tumor progression and poor prognosis. For high levels of HBsAg patients, we created an accurate and reliable nomogram to predict recurrence based on the Lasso-Cox regression analysis. The nomogram, including age, BCLC stage, tumor size, globulin, GGT, and bile acids, demonstrated adequate discrimination ability, which could better guide the clinical decisions.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethical approval was not required for the study involving humans in accordance with the local legislation and institutional requirements. Written informed consent to participate in this study was not required from the participants or the participants’ legal guardians/next of kin in accordance with the national legislation and the institutional requirements.

YX: Data curation, Writing – original draft, Writing – review & editing. WQ: Validation, Visualization, Writing – review & editing. QW: Data curation, Writing – review & editing. KL: Supervision, Writing – review & editing. RJ: Resources, Supervision, Writing – review & editing. YZ: Resources, Writing – review & editing.