Adjuvant chemotherapy can prolong recurrence-free survival but did not influence the type of recurrence or subsequent treatment in patients with colorectal liver metastases

Surrogacy of Recurrence-free Survival for Overall Survival as an Endpoint of Clinical Trials of Perioperative Adjuvant Therapy in Hepatobiliary-pancreatic Cancers: A Retrospective Study and Meta-analysis

OBJECTIVE

To assess the correlation between recurrence-free survival (RFS) and overall survival (OS) in the hepatobiliary-pancreatic (HBP) surgical setting to validate RFS as a surrogate endpoint.

BACKGROUND

Reliable surrogate endpoints for OS are still limited in the field of HBP surgery.

METHODS

We analyzed patients who underwent curative resection for HBP disease [986 patients with pancreatic ductal adenocarcinoma (PDAC), 1168 with biliary tract cancer (BTC), 1043 with hepatocellular carcinoma, and 1071 with colorectal liver metastasis] from September 2002 to June 2022. We also conducted meta-analyses of randomized controlled trials of neoadjuvant or adjuvant therapy to validate the surrogacy in PDAC and BTC.

RESULTS

Correlation coefficients between RFS and OS were low for hepatocellular carcinoma ( p = 0.67) and colorectal liver metastasis ( p = 0.53) but strong for PDAC ( p = 0.80) and BTC ( p = 0.75). In a landmark analysis, the concordance rates between survival or death at 5 years postoperatively and the presence or absence of recurrence at each time point (1, 2, 3, and 4 years) were 50%, 70%, 74%, and 77% for PDAC and 54%, 67%, 73%, and 78% for BTC, respectively, both increasing and reaching a plateau at 3 years. In a meta-analysis, the correlation coefficients for the RFS hazard ratio and OS hazard ratio in PDAC and BTC were p = 0.88 ( P < 0.001) and p = 0.87 ( P < 0.001), respectively.

CONCLUSIONS

Three-year RFS can be a reliable surrogate endpoint for OS in clinical trials of neoadjuvant or adjuvant therapy for PDAC and BTC.

Optimal policy tree to assist in adjuvant therapy decision-making after resection of colorectal liver metastases

BACKGROUND

Although systemic postoperative therapy after surgery for colorectal liver metastases is generally recommended, the benefit of adjuvant chemotherapy has been debated. We used machine learning to develop a decision tree and define which patients may benefit from adjuvant chemotherapy after hepatectomy for colorectal liver metastases.

METHODS

Patients who underwent curative-intent resection for colorectal liver metastases between 2000 and 2020 were identified from an international multi-institutional database. An optimal policy tree analysis was used to determine the optimal assignment of the adjuvant chemotherapy to subgroups of patients for overall survival and recurrence-free survival.

RESULTS

Among 1,358 patients who underwent curative-intent resection of colorectal liver metastases, 1,032 (76.0%) received adjuvant chemotherapy. After a median follow-up of 28.7 months (interquartile range 13.7-52.0), 5-year overall survival was 67.5%, and 3-year recurrence-free survival was 52.6%, respectively. Adjuvant chemotherapy was associated with better recurrence-free survival (3-year recurrence-free survival: adjuvant chemotherapy, 54.4% vs no adjuvant chemotherapy, 46.8%; P < .001) but no overall survival significant improvement (5-year overall survival: adjuvant chemotherapy, 68.1% vs no adjuvant chemotherapy, 65.7%; P = .15). Patients were randomly allocated into 2 cohorts (training data set, n = 679, testing data set, n = 679). The random forest model demonstrated good performance in predicting counterfactual probabilities of death and recurrence relative to receipt of adjuvant chemotherapy. According to the optimal policy tree, patient demographics, secondary tumor characteristics, and primary tumor characteristics defined the subpopulation that would benefit from adjuvant chemotherapy.

CONCLUSION

A novel artificial intelligence methodology based on patient, primary tumor, and treatment characteristics may help clinicians tailor adjuvant chemotherapy recommendations after colorectal liver metastases resection.

Deep learning-derived spatial organization features on histology images predicts prognosis in colorectal liver metastasis patients after hepatectomy

Histopathological images of colorectal liver metastases (CRLM) contain rich morphometric information that may predict patients' outcomes. However, to our knowledge, no study has reported any practical deep learning framework based on the histology images of CRLM, and their direct association with prognosis remains largely unknown. In this study, we developed a deep learning-based framework for fully automated tissue classification and quantification of clinically relevant spatial organization features (SOFs) in H&E-stained images of CRLM. The SOFs based risk-scoring system demonstrated a strong and robust prognostic value that is independent of the current clinical risk score (CRS) system in independent clinical cohorts. Our framework enables fully automated tissue classification of H&E images of CRLM, which could significantly reduce assessment subjectivity and the workload of pathologists. The risk-scoring system provides a time- and cost-efficient tool to assist clinical decision-making for patients with CRLM, which could potentially be implemented in clinical practice.

Posthepatectomy but not prehepatectomy chemotherapy was associated with a longer time to recurrence in patients with resectable colorectal liver metastases: Inverse probability of treatment weighting analysis

BACKGROUND

Patients with resectable colorectal liver metastases (CLM) are treated with surgery alone, surgery and posthepatectomy chemotherapy, or prehepatectomy chemotherapy and surgery. The optimal approach in terms of survival is unclear. We compared survival in the three treatment groups using inverse probability of treatment weighting (IPTW) analysis.

METHODS

Data from patients undergoing initial CLM resection in 2005-2018 were obtained from a prospectively maintained database. Our group treated resectable CLM with surgery alone but gradually adopted post- and prehepatectomy chemotherapy for patients with CLM number ≥5 after 2015. IPTW analysis was employed to adjust the characteristics of the three groups.

RESULTS

Of the 439 patients meeting the inclusion criteria, 175 underwent surgery alone, 135 underwent surgery and posthepatectomy chemotherapy, and 129 underwent prehepatectomy chemotherapy and surgery. After the IPTW adjustment, the demographic and clinicopathological characteristics were well balanced. The IPTW analysis revealed that the recurrence-free survival was better in patients undergoing surgery and posthepatectomy chemotherapy than in patients undergoing surgery alone (median recurrence-free survival, 1.3 years vs 0.7 years; P = .018). Overall survival was not significantly different between the three treatment approaches.

CONCLUSION

Posthepatectomy but not prehepatectomy chemotherapy prolongs the time to recurrence after curative-intent resection of CLM.

Optimizing Adjuvant Therapy after Surgery for Colorectal Cancer Liver Metastases: A Systematic Review

The liver is the most common site of colorectal cancer metastatic spread. Although metastasectomy is the gold standard for fit patients with resectable colorectal cancer liver metastases (CRLMs), their management after surgical treatment remains controversial. The objective of this systematic review was to collate the currently available data of the agents used in the adjuvant setting in order to define the most optimal therapeutic strategy. A systematic review of the literature was conducted by searching PubMed/Medline and Cochrane library databases. We included studies that evaluated the efficacy, the tolerability and the safety profile of various chemotherapeutic agents that are used as adjuvant treatment after surgical resection of CRLMs. The outcomes of interest were regression-free survival (RFS), disease-free survival (DFS), overall survival (OS) and severe toxicities. From 543 initial articles, 29 publications with 7028 patients were finally included. In general, the results of the eligible studies indicated that adjuvant therapy after resection of CRLMs led to improved RFS/DFS rates, but this benefit did not contribute to a statistically significant prolongation of OS. Moreover, the choice of the therapeutic strategy, namely systematic or regional chemotherapy or the combination of both, did not seem to have a differential impact on patient outcomes. However, these results should be interpreted with caution since the majority of the chosen studies are of low or moderate quality. In this context, further high-quality clinical trials conducted on patient sub-populations with modern therapies are required in order to reduce in-study and between-study heterogeneity and determine which patients are expected to derive the maximum benefit from adjuvant therapy after surgery for CRLMs.

Recurrence-free survival versus overall survival as a primary endpoint for studies of resected colorectal liver metastasis: a retrospective study and meta-analysis

BACKGROUND

Recurrence-free survival has been used as a surrogate endpoint for overall survival in trials involving patients with resected colorectal liver metastases. We aimed to assess the correlation between recurrence-free survival and overall survival after resection of colorectal liver metastases to determine the adequacy of this surrogate endpoint.

METHODS

In this retrospective study and meta-analysis, we compiled an institutional cohort of consecutive patients who had complete resection of colorectal liver metastases from the Memorial Sloan Kettering Cancer Center (New York, NY, USA) prospective database. Patients were eligible for inclusion if they were aged 18 years or older, and underwent hepatectomy, with or without operative ablation, between Jan 1, 1991, and April 30, 2019. We estimated overall survival and recurrence-free survival probabilities at various timepoints using the Kaplan-Meier method, and we assessed pairwise associations between these endpoints using Spearman's rank correlation. We also did a meta-analysis of adjuvant phase 3 clinical trials for colorectal liver metastases to assess the correlation between hazard ratios (HRs) for recurrence-free survival and overall survival. We searched MEDLINE for articles of phase 3 randomised controlled trials analysing adjuvant treatment strategies for resected colorectal metastases from database inception to Jan 1, 2022. The titles and abstracts of identified studies were screened before full-text screening and summary data were either recalculated or extracted manually from the published Kaplan-Meier curves (depending on data availability).

FINDINGS

Data were available for 3299 patients in the institutional database, of whom 2983 were eligible for inclusion in our cohort. Median follow-up was 8·4 years (95% CI 7·9-9·1) , during which time there were 1995 (67%) disease recurrences and 1684 (56%) deaths. Median recurrence-free survival was 1·3 years (95% CI 1·3-1·4) and median overall survival was 5·2 years (95% CI 5·0-5·5). 1428 (85%) of 1684 deaths were preceded by recurrence, and median time from recurrence to death was 2·0 years (IQR 1·0-3·4). Pairwise correlations between recurrence-free survival and overall survival were low to moderate, with a correlation estimate ranging from 0·30 (SD 0·17) to 0·56 (0·13). In the meta-analysis of adjuvant clinical trials, the Spearman's correlation coefficient between recurrence-free survival HR and overall survival HR was r=0·20 (p=0·71).

INTERPRETATION

We found a minimal correlation between recurrence-free survival and overall survival after resection of colorectal liver metastases. Recurrence-free survival is an inadequate surrogate endpoint for overall survival in this disease setting.

FUNDING

US National Cancer Institute.

Repeat Resection for Advanced Colorectal Liver Metastases-Does it have the Potential for Cure?

BACKGROUND

Although surgical resection is the only potential treatment for patients with colorectal liver metastases (CLM), the actual cure is rare in patients with advanced CLM. Repeat resection (RR) is the most effective treatment in patients with recurrence; however, whether patients with initially advanced CLM achieve cure throughout RR or experience repeated recurrence even after RR remains unclear. In this study, we analyzed whether patients with advanced CLM achieve cure after RR.

METHODS

Consecutive patients who underwent initial hepatectomy with curative intent for CLM from January 1999 to August 2007 were included. Patients who were alive at 10 years from the initial hepatectomy without any evidence of recurrence were defined as cured. Cure rates were compared between patients with Fong's clinical risk score (CRS) of ≥ 3 and those with CRS of ≤ 2.

RESULTS

A total of 257 patients were included and followed up. Among them, 93 (36.2%) patients achieved actual cure postoperatively. The cure rate of patients with a CRS of ≥ 3 was 32.4% (33/102), which was not different from that of patients with a CRS of ≤ 2 (38.7% [60/155]; p = 0.299), although former patients had higher recurrence rate after the initial hepatectomy than latter ones (85.3% vs. 72.3%; p = 0.014). The cure rates after the initial, second, and third resections were 23.0% (59/257), 30.0% (24/80), and 22.5% (7/31), respectively. In multivariate analysis, RR was determined as an independent favorable factor of achieving cure.

CONCLUSIONS

RR had a potential to cure patients with advanced CLM, and one-third of them achieved cure.