Tumor burden affects the progression pattern on the prognosis in patients treated with sorafenib.

The progression pattern of tumors has an impact on the survival of patients with advanced hepatocellular carcinoma (HCC) and has been applied in the design of clinical trials for multiple second-line drugs. Previous research results have been contradictory, and the clinical impact of different progression patterns and their role in survival are still in question. Purpose: The study aims to analyze the impact of different progression patterns and tumor burden size on survival of HCC patients, as well as their interactions, through a retrospective cohort study. Patients and methods: The study involved 538 patients who had undergone treatment with sorafenib and had shown radiographic progression. The progression pattern was analyzed using Cox regression by including an interaction term between progression pattern and tumor burden, which was then visualized through a graphical analysis. Tumor burden was categorized into low, medium, and high subgroups based on the six-and-twelve criteria, allowing for an exploration of the effect of progression pattern on survival in different tumor burden situations. Results: Compared to patients with only intrahepatic progression (NIH/IHG) with an overall survival (OS) of 14.1/19.9 months and post-progression survival (PPS) of 8.1/13.1 months respectively, patients with extrahepatic lesions (NEH/EHG) had worse overall and postprogressive survival (OS: 9.3/9.2 months, PPS: 4.9/5.1 months). The hazard ratio for extrahepatic progression (NEH/EHG) compared to intrahepatic progression (NIH/IHG) at low, medium, and high tumor burden were [HR 2.729, 95%CI 1.189-6.263], [HR 1.755, 95%CI 1.269-2.427], and [HR 1.117, 95%CI 0.832-1.499], respectively. Conclusion: The study concluded that the interaction between the tumor progression patterns and tumor burden significantly affects the prognosis of HCC patients. As the tumor burden increases, the sensitivity of the patient's risk of death to the progression pattern decreases. These findings are valuable in personalized treatment and trial design.

Development and validation of a prognostic score to identify the optimal candidate for preemptive TIPS in patients with cirrhosis and acute variceal bleeding.

BACKGROUND AND AIM: Baveno VII workshop recommends the use of preemptive TIPS (p-TIPS) in patients with cirrhosis and acute variceal bleeding (AVB) at high- risk of treatment failure. However, the criteria defining "high-risk" have low clinical accessibility or include subjective variables. We aimed to develop and externally validate a model for better identification of p-TIPS candidates. APPROACH AND RESULTS: The derivation cohort included 1554 patients with cirrhosis and AVB who were treated with endoscopy plus drug (n = 1264) or p-TIPS (n = 290) from 12 hospitals in China between 2010 and 2017. We first used competing risk regression to develop a score for predicting 6-week and 1-year mortality in patients treated with endoscopy plus drugs, which included age, albumin, bilirubin, international normalized ratio, white blood cell, creatinine, and sodium. The score was internally validated with the bootstrap method, which showed good discrimination (6 wk/1 y concordance-index: 0.766/0.740) and calibration, and outperformed other currently available models. In the second stage, the developed score was combined with treatment and their interaction term to predicate the treatment effect of p-TIPS (mortality risk difference between treatment groups) in the whole derivation cohort. The estimated treatment effect of p-TIPS varied substantially among patients. The prediction model had good discriminative ability (6 wk/1 y c -for-benefit: 0.696/0.665) and was well calibrated. These results were confirmed in the validation dataset of 445 patients with cirrhosis with AVB from 6 hospitals in China between 2017 and 2019 (6-wk/1-y c-for-benefit: 0.675/0.672). CONCLUSIONS: We developed and validated a clinical prediction model that can help to identify individuals who will benefit from p-TIPS, which may guide clinical decision-making.

Pre-emptive TIPS in high-risk acute variceal bleeding. An updated and revised individual patient data meta-analysis.

BACKGROUND AND AIMS: A previous individual patient data meta-analysis (IPD-MA) showed that compared with drugs+endoscopy, the placement of transjugular portosystemic shunt within 72 hours of admission (pre-emptive transjugular intrahepatic portosystemic shunt: p-TIPS) increases the survival of high-risk patients (Child-Pugh B+ active bleeding and Child-Pugh C<14 points) with cirrhosis and acute variceal bleeding. However, the previous IPD-MA was not a two-stage meta-analysis, did not consider the potential risk of selection bias of observational studies, and did not include the most recent randomized clinical trial. We performed an updated and revised IPD-MA to reassess the efficacy of p-TIPS, addressing all previous issues. APPROACH AND RESULTS: We included all studies from the previous IPD-MA and searched for other possible eligible publications until September 2022. We performed a two-stage IPD-MA of data from 8 studies (4 randomized clinical trials and 4 observational). In addition, we performed a sensitivity analysis excluding those patients dying up to the first 72 hours after admission in the Drugs+Endoscopy arms of the 4 observational studies. The primary end point was the effects of p-TIPS versus Drugs+Endoscopy on 1-year survival.We identified 1389 patients (342 p-TIPS and 1047 Drugs+Endoscopy). The two-stage IPD-MA showed that p-TIPS significantly reduced the mortality in the overall population (HR=0·43, 95% CI: 0.32-0.60, p <0.001. This effect was observed in both subgroups of patients with Child-Pugh. The sensitivity analysis confirmed the survival benefit of p-TIPS. CONCLUSIONS: The updated two-stage IPD-MA confirms the significant survival advantage of p-TIPS in high-risk patients with cirrhosis and acute variceal bleeding. As a result, we recommend p-TIPS as the preferred first-choice treatment for these patients.

Guidelines for the Diagnosis and Treatment of Primary Liver Cancer (2022 Edition).

Background: Primary liver cancer, of which around 75-85% is hepatocellular carcinoma in China, is the fourth most common malignancy and the second leading cause of tumor-related death, thereby posing a significant threat to the life and health of the Chinese people. Summary: Since the publication of Guidelines for Diagnosis and Treatment of Primary Liver Cancer in China in June 2017, which were updated by the National Health Commission in December 2019, additional high-quality evidence has emerged from researchers worldwide regarding the diagnosis, staging, and treatment of liver cancer, that requires the guidelines to be updated again. The new edition (2022 Edition) was written by more than 100 experts in the field of liver cancer in China, which not only reflects the real-world situation in China but also may reshape the nationwide diagnosis and treatment of liver cancer. Key Messages: The new guideline aims to encourage the implementation of evidence-based practice and improve the national average 5-year survival rate for patients with liver cancer, as proposed in the "Health China 2030 Blueprint."

Outcome of Children with Transjugular Intrahepatic Portosystemic Shunt: A Meta-Analysis of Individual Patient Data.

PURPOSE: The purpose of the study was to investigate outcome after pediatric transjugular intrahepatic portosystemic shunt (TIPS) with respect to survival MATERIAL AND METHODS: After searching for studies on TIPS in children in Ovid, Medline, Embase, Scopus and Cochrane published between 2000 and 2022, individual patient data were retrieved from five retrospective cohorts. Overall survival (OS) and transplant-free survival (TFS) were calculated using Kaplan-Meier analysis and log-rank test and compared to the indication (ascites vs. variceal bleeding) as well as to the level of obstruction (pre-hepatic vs. hepatic vs. post-hepatic). Additionally, TIPS patency was analyzed. RESULTS: n = 135 pediatric patients were included in the final analysis. Indication for pediatric TIPS creation was heterogeneous among the included studies. TIPS patency decreased from 6 to 24 months, subsequent pediatric liver transplantation was performed in 22/135 (16.3%) of cases. The presence of ascites was related with poorer TFS (HR 2.3, p = 0.023), while variceal bleeding was not associated with impaired survival. Analysis of the level of obstruction (pre-hepatic, hepatic and post-hepatic) failed to prove significantly reduced OS for post-hepatic obstruction (HR 3.2, p = 0.092) and TFS (HR 1.3, p = 0.057). There was no difference in OS and TFS according to age at time of TIPS placement. CONCLUSIONS: The presence of ascites associates with impaired survival after TIPS in children, with no differences in survival according to the age of the child. Interventional shunt procedures can be considered feasible for all ages. LEVEL OF EVIDENCE: Level 2a.

Association of nonmalignant portal vein thrombosis and clinical outcomes in patients with cirrhosis and acute variceal bleeding: a multicenter observational study.

BACKGROUND AND AIM: Baveno VII workshop recommends management of acute variceal bleeding (AVB) in cirrhotic patients with nonmalignant portal vein thrombosis (PVT) should be performed according to the guidelines for patients without PVT. Nevertheless, whether PVT affects the outcome of patients with cirrhosis and AVB remains unclear. The aim of this study was to assess the clinical impact of PVT on the outcomes in the pre-emptive TIPSS eligible patients with cirrhosis and AVB. METHODS: From December 2010 to June 2016, 1219 consecutive cirrhotic patients admitted due to AVB with (n = 151; 12.4%) or without PVT (n = 1068; 87.6%), who received drug plus endoscopic treatment (a combination of vasoactive drugs, antibiotics, and endoscopic ligation for AVB, followed by beta-blockers plus variceal ligation for prevention of rebleeding) were retrospectively included. Fine and Gray competing risk regression models were taken to evaluate the impact of PVT on clinical outcomes after adjusting for potential confounders. RESULTS: During follow-up, 211 patients (17.3%) died, 490 (40.2%) experienced further bleeding, and 78 (6.4%) experienced new or worsening ascites within 1 year. Compared with those without PVT, patients with PVT had a similar risk of mortality (PVT vs no-PVT: 19.9% vs 16.7% at 1 year; adjusted HR 0.88, 95%CI 0.51-1.52, p = 0.653), further bleeding (47.0% vs 39.2% at 1 year, adjusted HR 1.19, 95% CI 0.92-1.53, p = 183), and new or worsening ascites (7.9% vs 9.6%, adjusted HR 0.70, 95% CI 0.39-1.28, p = 0.253) after adjusting for confounders in multivariable models. These findings were consistent across different relevant subgroups and confirmed by propensity score matching analysis. CONCLUSIONS: Our study showed no evidence that the PVT was associated with an improved or worsened outcome among cirrhotic patients with AVB who received standard treatment.

TIPS prevents further decompensation and improves survival in patients with cirrhosis and portal hypertension in an individual patient data meta-analysis.

BACKGROUND & AIMS: Further decompensation represents a prognostic stage of cirrhosis associated with higher mortality compared with first decompensation. A transjugular intrahepatic portosystemic shunt (TIPS) is indicated to prevent variceal rebleeding and for refractory ascites, but its overall efficacy to prevent further decompensations is unknown. This study assessed the incidence of further decompensation and mortality after TIPS vs. standard of care (SOC). METHODS: Controlled studies assessing covered TIPS compared with SOC for the indication of refractory ascites and prevention of variceal rebleeding published from 2004 to 2020 were considered. We collected individual patient data (IPD) to perform an IPD meta-analysis and to compare the treatment effect in a propensity score (PS)-matched population. Primary outcome was the incidence of further decompensation and the secondary outcome was overall survival. RESULTS: In total, 3,949 individual patient data sets were extracted from 12 controlled studies and, after PS matching, 2,338 patients with similar characteristics (SOC = 1,749; TIPS = 589) were analysed. The 2-year cumulative incidence function of further decompensation in the PS-matched population was 0.48 (95% CI 0.43-0.52) in the TIPS group vs. 0.63 (95% CI 0.61-0.65) in the SOC group (stratified Gray's test, p <0.0001), considering mortality and liver transplantation as competing events. The lower further decompensation rate with TIPS was confirmed by adjusted IPD meta-analysis (hazard ratio 0.44; 95% CI 0.37-0.54) and was consistent across TIPS indication subgroups. The 2-year cumulative survival probability was higher with TIPS than with SOC (0.71 vs. 0.63; p = 0.0001). CONCLUSIONS: The use of TIPS for refractory ascites and for prevention of variceal rebleeding reduces the incidence of a further decompensation event compared with SOC and increases survival in highly selected patients. IMPACT AND IMPLICATIONS: A further decompensation (new or worsening ascites, variceal bleeding or rebleeding, hepatic encephalopathy, jaundice, hepatorenal syndrome-acute kidney injury and spontaneous bacterial peritonitis) in patients with cirrhosis is associated with a poor prognosis. Besides the known role of TIPS in portal hypertension-related complications, this study shows that TIPS is also able to decrease the overall risk of a further decompensation and increase survival compared with standard of care. These results further support the role of TIPS in the management of patients with cirrhosis and portal hypertension-related complications.

Anticoagulation improves survival in patients with cirrhosis and portal vein thrombosis: The IMPORTAL competing-risk meta-analysis.

BACKGROUND & AIMS: Previous meta-analyses demonstrated the safety and efficacy of anticoagulation in the recanalization of portal vein thrombosis in patients with cirrhosis. Whether this benefit translates into improved survival is unknown. We conducted an individual patient data (IPD) meta-analysis to assess the effect of anticoagulation on all-cause mortality in patients with cirrhosis and portal vein thrombosis. METHODS: In this IPD meta-analysis, we selected studies comparing anticoagulation vs. no treatment in patients with cirrhosis and portal vein thrombosis from PubMed, Embase, and Cochrane databases (until June 2020) (PROSPERO no.: CRD42020140026). IPD were subsequently requested from authors. The primary outcome - the effect of anticoagulation on all-cause mortality - was assessed by a one-step meta-analysis based on a competing-risk model with liver transplantation as the competing event. The model was adjusted for clinically relevant confounders. A multilevel mixed-effects logistic regression model was used to determine the effect of anticoagulation on recanalization. RESULTS: Individual data on 500 patients from five studies were included; 205 (41%) received anticoagulation and 295 did not. Anticoagulation reduced all-cause mortality (adjusted subdistribution hazard ratio 0.59; 95% CI 0.49-0.70), independently of thrombosis severity and recanalization. The effect of anticoagulation on all-cause mortality was consistent with a reduction in liver-related mortality. The recanalization rate was higher in the anticoagulation arm (adjusted odds ratio 3.45; 95% CI 2.22-5.36). The non-portal-hypertension-related bleeding rate was significantly greater in the anticoagulation group. CONCLUSIONS: Anticoagulation reduces all-cause mortality in patients with cirrhosis and portal vein thrombosis independently of recanalization, but at the expense of increasing non-portal hypertension-related bleeding. PROSPERO REGISTRATION NUMBER: CRD42020140026. IMPACT AND IMPLICATIONS: Anticoagulation is effective in promoting recanalization of portal vein thrombosis in patients with cirrhosis, but whether this benefit translates into improved survival is controversial. Our individual patient data meta-analysis based on a competing-risk model with liver transplantation as the competing event shows that anticoagulation reduces all-cause mortality in patients with cirrhosis and portal vein thrombosis independently of recanalization. According to our findings, portal vein thrombosis may identify a group of patients with cirrhosis that benefit from long-term anticoagulation.

'Potentially curative therapies' for hepatocellular carcinoma: how many patients can actually be cured?

BACKGROUND: Treatment of hepatocellular carcinoma (HCC) is predicated on early diagnosis such that 'curative therapies' can be successfully applied. The term 'curative' is, however, poorly quantitated. We aimed to complement our previous work by developing a statistical model to predict cure after ablation and to use this analysis to compare the true curative potential of the various 'curative' therapies. METHODS: We accessed data from 1571 HCC patients treated in 5 centres receiving radiofrequency (RFA) or microwave (MWA) ablation and used flexible parametric modelling to determine the curative fraction. The results of this analysis were then combined with our previous estimations to provide a simple calculator applicable to all patients undergoing potentially curative therapies. RESULTS: The cure fraction was 18.3% rising to about 40% in patients with good liver function and very small tumours. CONCLUSION: Cure for HCC treated with ablation occurs in the order of 20% to 30%, similar to that achievable by resection but much inferior to transplantation where the analogous figure is >70%. We provide a 'calculator' that permits clinicians to estimate the chance of cure for any individual patient, based on readily available clinical features.

Transjugular intrahepatic portosystemic shunt for portal hypertension: 30 years experience from China.

Liver diseases are a major cause of illness and death worldwide. In China, liver diseases, primarily viral hepatitis, affect approximately 300 million people, thus having a major impact on the global burden of liver diseases. Portal hypertension is the most severe complication of chronic liver diseases, including ascites, hepatic encephalopathy and bleeding from gastroesophageal varices. Transjugular intrahepatic portosystemic shunt (TIPS) represents a very effective treatment of these complications. Since its introduction 30 years ago in China, the use of TIPS has evolved and has played an increasingly important role in the management of the complications of portal hypertension. This review will focus on the history, current application and management of complications of TIPS in China.

CLIF-C AD score predicts survival benefit from pre-emptive TIPS in individuals with Child-Pugh B cirrhosis and acute variceal bleeding.

Background & Aims: Among individuals with Child-Pugh B cirrhosis and acute variceal bleeding (AVB), the Baveno VII workshop recommended pre-emptive TIPS in those with a Child-Pugh score of 8-9 and active bleeding at initial endoscopy (Child B8-9 + AB criteria). Nevertheless, whether this criterion is superior to the CLIF-Consortium acute decompensation score (CLIF-C ADs) remains unclear. Methods: Data on 1,021 consecutive individuals with Child-Pugh B cirrhosis and AVB from 13 university hospitals in China who were treated with pre-emptive TIPS (n = 297) or drug plus endoscopic treatment (n = 724) between 2010 to 2019 were retrospectively analysed. A competing risk regression model was used to compare the outcomes between the two groups after adjusting for confounders. The concordance-statistic for benefit (c-for-benefit) was used to evaluate a models' ability to predict treatment benefit (risk difference between treatment groups). Results: Pre-emptive TIPS was associated with reduced mortality compared to drug plus endoscopic treatment (adjusted hazard ratio 0.62, 95% CI 0.44 to 0.88). A higher baseline CLIF-C AD score was associated with greater survival benefit (i.e., larger absolute mortality risk reduction). After adjusting for confounders, a survival benefit was observed in individuals with CLIF-C ADs ≥48 or Child-Pugh B8-9 with active bleeding, but not in those with CILF-C ADs <48, no active bleeding or Child-Pugh B7 with active bleeding. The c-for-benefit of CILF-C ADs for predicting survival benefit was higher than that of Child B8-9+AB criteria. Conclusions: In individuals with Child-Pugh B cirrhosis and AVB, CLIF-C ADs predicts survival benefit from pre-emptive TIPS and outperforms the Child B8-9+AB criteria. Prospective validation should be performed to confirm this result, especially for other aetiologies of cirrhosis. Impact and implications: In this study, among individuals with Child-Pugh B cirrhosis and acute variceal bleeding, the CLIF-Consortium acute decompensation (CLIF-C AD) score could predict the survival benefit from pre-emptive TIPS, with patients with higher CLIF-C AD scores benefiting more from pre-emptive TIPS. Furthermore, the CLIF-C AD score outperformed the Child B8-9 plus active bleeding criteria in terms of discriminating between those who obtained more benefit vs. less benefit from pre-emptive TIPS. Depending on prospective validation, the CLIF-C AD score could be used as the model of choice to determine who should undergo pre-emptive TIPS.

Lenvatinib with or without Concurrent Drug-Eluting Beads Transarterial Chemoembolization in Patients with Unresectable, Advanced Hepatocellular Carcinoma: A Real-World, Multicenter, Retrospective Study.

Introduction: Lenvatinib is the first-line treatment for advanced hepatocellular carcinoma (HCC). We aimed to compare the clinical outcomes of lenvatinib plus drug-eluting beads transarterial chemoembolization (DEB-TACE) versus lenvatinib alone in real-world practice. Methods: This retrospective analysis included 142 consecutive patients who received lenvatinib plus DEB-TACE and 69 patients who received lenvatinib alone as first-line treatment from 15 Chinese academic centers from November 2018 to November 2019. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR) were evaluated by modified Response Evaluation Criteria in Solid Tumors criteria, and safety profiles were compared between the two groups. Results: The median OS and PFS were significantly longer in the combined therapy group than in the monotherapy group in whole cohort (median OS, 15.9 vs. 8.6 months, p = 0.0022; median PFS, 8.6 vs. 4.4 months, p < 0.001) and after propensity score matching analysis (median OS, 13.8 vs. 7.8 months, p = 0.03; median PFS, 7.8 vs. 4.5 months, p = 0.009). Moreover, the treatment option was an independent prognostic factor for OS and PFS with adjustment based upon baseline characteristics (adjusted hazard ratio [HR]: 0.53, 95% confidence interval [CI]: 0.36-0.78, p = 0.001, and adjusted HR: 0.42, 95% CI: 0.30-0.60, p < 0.001, respectively) and propensity score (adjusted HR: 0.52, 95% CI: 0.36-0.76, p = 0.001, and adjusted HR: 0.46, 95% CI: 0.33-0.64, p < 0.001, respectively). Moreover, a greater ORR was observed in the combined group (ORR: 46.48% vs. 13.05%, p < 0.001). Furthermore, the most common adverse events (AEs) were elevated aspartate aminotransferase (54.9%) and fatigue (46.4%) in the lenvatinib plus DEB-TACE group and lenvatinib group, respectively. Most AEs were mild-to-moderate and manageable. Conclusions: With well-tolerated safety, lenvatinib plus DEB-TACE was more effective than lenvatinib monotherapy in improving OS, PFS, and ORR. Thus, it may be a promising treatment for advanced HCC. Future prospective studies confirming these findings are warranted.

Transjugular intrahepatic portosystemic shunt with or without gastro-oesophageal variceal embolisation for the prevention of variceal rebleeding: a randomised controlled trial.

BACKGROUND: The role of variceal embolisation at the time of transjugular intrahepatic portosystemic shunt (TIPS) creation for the prevention of gastro-oesophageal variceal rebleeding remains controversial. This study aimed to evaluate whether adding variceal embolisation to TIPS placement could reduce the incidence of rebleeding after TIPS in patients with cirrhosis. METHODS: We did an open-label, randomised controlled trial at one university hospital in China. Eligible patients were aged 18-75 years with cirrhosis and had variceal bleeding in the past 6 weeks, and they were randomly assigned (1:1) to receive TIPS (with a covered stent in both groups) plus variceal embolisation (TIPS plus embolisation group) or TIPS alone (TIPS group) to prevent variceal rebleeding. Randomisation was done using a web-based randomisation system using a Pocock and Simon's minimisation method, stratified by Child-Pugh class (A vs B vs C). Clinicians and patients were not masked to treatment allocation; individuals involved in data analysis were masked to treatment assignment. The primary endpoint was the 2-year cumulative incidence of variceal rebleeding after randomisation, and analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, NCT02119988. FINDINGS: Between June 16, 2014, and Feb 3, 2016, 205 patients were screened, of whom 134 were randomly allocated to the TIPS plus embolisation group (n=69) and the TIPS group (n=65). TIPS placement and variceal embolisation was successful in all 134 patients, all were included in the analysis. There was no significant difference in the 2-year cumulative incidence of variceal rebleeding between the two groups (TIPS plus embolisation 11·6% [95% CI 4·0-19·1] vs TIPS 13·8% [5·4-22·2]; hazard ratio 0·82 [95% CI 0·42-1·61]; p=0·566). Adverse events were similar between the two groups; the most common adverse events were peptic ulcer or gastritis (12 [17%] of patients in the TIPS plus embolisation group vs 13 [20%] of patients in the TIPS group), new or worsening ascites (ten [14%] vs six [9%]), and hepatocellular carcinoma (four [6%] vs six [9%]). The numbers of deaths were also similar between groups (24 [35%] vs 25 [38%]) INTERPRETATION: Adding variceal embolisation to TIPS did not significantly reduce the incidence of variceal rebleeding in patients with cirrhosis. Our findings do not support concomitant variceal embolisation during TIPS for the prevention of variceal rebleeding. FUNDING: National Key Technology R&D Program, Boost Program of Xijing Hospital, and China Postdoctoral Science Foundation.

Optimal time point of response assessment for predicting survival is associated with tumor burden in hepatocellular carcinoma receiving repeated transarterial chemoembolization.

OBJECTIVES: Objective response rate (ORR) under mRECIST criteria after transarterial chemoembolization (TACE) is a well-perceived surrogate endpoint of overall survival (OS). However, its optimal time point remains controversial and may be influenced by tumor burden. We aim to investigate the surrogacy of initial/best ORR in relation to tumor burden. METHODS: A total of 1549 eligible treatment-naïve patients with unresectable hepatocellular carcinoma (HCC), Child-Pugh score ≤ 7, and performance status score ≤ 1 undergoing TACE between January 2010 and May 2016 from 17 academic hospitals were retrospectively analyzed. Based on "six-and-twelve" criteria, tumor burden was graded as low, intermediate, and high if the sum of the maximum tumor diameter and tumor number was ≤ 6, > 6 but ≤ 12, and > 12, respectively. RESULTS: Both initial and best ORRs interacted with tumor burden. Initial and best ORRs could equivalently predict and correlate with OS in low (adjusted HR, 2.55 and 2.95, respectively, both p < 0.001; R = 0.84, p = 0.035, and R = 0.97, p = 0.002, respectively) and intermediate strata (adjusted HR, 1.81 and 2.22, respectively, both p < 0.001; R = 0.74, p = 0.023, and R = 0.9, p = 0.002, respectively). For high strata, only best ORR exhibited qualified surrogacy (adjusted HR, 2.61, p < 0.001; R = 0.70, p = 0.035), whereas initial ORR was not significant (adjusted HR, 1.08, p = 0.357; R = 0.22, p = 0.54). CONCLUSIONS: ORR as surrogacy of OS is associated with tumor burden. For patients with low/intermediate tumor burden, initial ORR should be preferred in its early availability upon similar sensitivity, whereas for patients with high tumor burden, best ORR has optimal sensitivity. Timing of OR assessment should be tailored according to tumor burden. KEY POINTS: • This is the first study utilizing individual patient data to comprehensively analyze the surrogacy of ORR with a long follow-up period. • Optimal timing of ORR assessment for predicting survival should be tailored according to tumor burden. • For patients with low and intermediate tumor burden, initial ORR is optimal for its timeliness upon similar sensitivity with best ORR. For patients with high tumor burden, best ORR has optimal sensitivity.