Locoregional treatment for colorectal liver metastases aiming for precision medicine

Associations of KRAS Point Mutations with Survival of Patients Who Underwent Curative-Intent Resection of Colorectal Liver Metastases

BACKGROUND

The oncologic significance of specific KRAS point mutations for patients with colorectal liver metastases (CLM) is uncertain. This study aimed to assess the prognostic impact of KRAS point mutations on patients who underwent surgery for CLM.

METHODS

Patients who underwent curative-intent surgery for CLM from 2001 to 2020 were selected for the study. In the study, KRAS point mutations and other clinicopathologic variables were examined for association with survival.

RESULTS

The study classified 798 patients into five groups by KRAS mutation status as follows: wild-type (n = 412, 51.6%), G12D (n = 123, 15.4%), G12V (n = 88, 11.0%), G13D (n = 61, 7.6%), and "Other" mutations (n = 114, 14.3%). For the patients with G12V substitutions, TP53 mutation was associated with worse overall survival (OS) (hazard ratio [HR], 2.64; 95% confidence interval [CI], 1.04-6.66; P = 0.041), but was not associated with a survival difference for the other four groups. The patients with co-occurring KRAS G12V and TP53 had a median OS of 4.4 years and a 5-year OS rate of 39.8%. In contrast, the patients with KRAS G12V mutation and wild-type TP53 had a median OS of 7.3 years and a 5-year OS rate of 75.9%, similar to the corresponding values for the patients with wild-type KRAS. Co-occurring KRAS G12V and TP53 mutations were independently associated with worse OS in the entire cohort (HR, 2.08; 95% CI, 1.15-3.76; P = 0.015).

CONCLUSIONS

This study showed that KRAS G12V mutation is associated with worse OS for patients undergoing curative-intent CLM resection, but only those with co-occurring TP53 mutation. Prognosis after surgery for CLM should not be stratified by KRAS mutation site alone.

Synthetic tumor extracellular volume as a predictive biomarker for colorectal liver metastasis patients prior to curative hepatectomy

OBJECTIVE

This study evaluated the prognostic value of synthetic tumor extracellular volume fraction (ECV) and its association with somatic gene alternations in patients with colorectal liver metastases (CRLM) receiving neoadjuvant chemotherapy.

METHODS

This retrospective single-center study included patients undergoing curative hepatectomy after neoadjuvant chemotherapy for CRLM (2013-2020). Contrast-enhanced computed tomography (CT) studies obtained after neoadjuvant chemotherapy were used to calculate synthetic ECV and synthetic hematocrit by linear regression analysis. Patients were grouped according to synthetic ECV cutoff point based on the Youden index. Multivariate analyses were performed with Cox regression models to analyze the prognostic factors of overall survival (OS) and recurrence-free survival (RFS).

RESULTS

A total of 209 patients (median age 56 years, 119 men) were enrolled. Synthetic ECV correlated well with conventional ECV (r = 0.996, p < 0.0001) with minimal bias, according to the Bland-Altman analysis (bias = 0.007). The optimal synthetic ECV cutoff point was determined to be 21%, with 115 patients having high ECV and 94 low ECV. Multivariable analysis for predicting high ECV demonstrated significant associations with synchronous CRLM, anti-VEGF agent-containing regimen, and RAS-BRAF mutation (p = 0.022, < 0.001, and = 0.003, respectively). OS and RFS were significantly higher in the high ECV group compared to the low ECV group (p = 0.019 and p = 0.015, respectively). High ECV was independently associated with improved OS (HR 0.55, 95% CI 0.34-0.91) and RFS (HR 0.71, 95% CI 0.52-0.97).

CONCLUSIONS

Synthetic ECV can help predict OS and RFS in patients undergoing curative-intent CRLM resection after neoadjuvant chemotherapy and could be a useful imaging biomarker to stratify risk.

KEY POINTS

Question There is a need for a biomarker predictive of treatment response after neoadjuvant chemotherapy, prior to curative-intent colorectal liver metastases. Findings Synthetic extracellular volume fraction can help predict overall and recurrence-free survival and is associated with somatic gene alterations. Clinical relevance Prognostic markers of response to neoadjuvant chemotherapy in curative-intent colorectal liver metastases include extracellular volume fraction. Synthetic extracellular volume fraction obviates the need for hematocrit; a simplification that is expected to streamline routine clinical practice.

Propensity Score-Matched Analysis of Liver Venous Deprivation and Portal Vein Embolization Before Planned Hepatectomy in Patients with Extensive Colorectal Liver Metastases and High-Risk Factors for Inadequate Regeneration

BACKGROUND

Liver venous deprivation (LVD) is known to induce better future liver remnant (FLR) hypertrophy than portal vein embolization (PVE). The role of LVD, compared with PVE, in inducing FLR hypertrophy and allowing safe hepatectomy for patients with extensive colorectal liver metastases (CLM) and high-risk factors for inadequate hypertrophy remains unclear.

METHODS

Patients undergoing LVD (n = 22) were matched to patients undergoing PVE (n = 279) in a 1:3 ratio based on propensity scores, prior to planned hepatectomy for CLM at a single center (1998-2023). The propensity scores accounted for high-risk factors for inadequate hypertrophy, namely pre-procedure standardized FLR (sFLR), body mass index, number of systemic therapy cycles, an extension of PVE to segment IV portal vein branches, prior resection, and chemotherapy-associated liver injury.

RESULTS

The matched cohort included 78 patients (LVD, n = 22; PVE, n = 56). Baseline characteristics were comparable. The number of tumors in the whole liver was similar but more LVD patients had five or more tumors in the left liver (32% vs. 11%; p = 0.024). Post-procedure sFLR was similar but LVD patients had a significantly higher degree of hypertrophy (16% vs. 11%; p = 0.017) and kinetic growth rate (3.9 vs. 2.4% per week; p = 0.006). More LVD patients underwent extended right hepatectomy (93% vs. 55%; p = 0.008). Only one patient had postoperative hepatic insufficiency after PVE, and no patients died within 90 days of hepatectomy.

CONCLUSION

In patients with extensive CLM and high-risk factors, LVD is associated with better FLR hypertrophy compared with PVE and allows for safely performing curative-intent extended major hepatectomy.

RAS-Beppu Classification: A New Recurrence Risk Classification System Incorporating the Beppu Score and RAS Status for Colorectal Liver Metastases

Background: Preoperative recurrence risk stratification for colorectal liver metastases (CRLM) undergoing hepatectomy is essential when designing a treatment strategy. We developed a Beppu classification system consisting of three risk groups and found that the RAS mutation increased risk in low- and moderate-risk patients. Methods: A total of 173 patients undergoing initial hepatectomy for CRLM between 2004 and 2020 were analyzed. Disease-free survival (DFS) and overall survival (OS) were assessed. Patients in the low- and moderate-risk groups of the Beppu classification with RAS mutations were moved into the moderate- and high-risk groups, respectively, in the RAS-Beppu classification. Results: The DFS curves of the three risk groups in the Beppu and RAS-Beppu classification were significantly different. Five-year DFS rates were 57%, 31%, and 16% in the RAS-Beppu classification of low-, moderate-, and high-risk groups, respectively. With multivariate analysis, Beppu classifications (p = 0.0017) and RAS-Beppu classifications (p = 0.0002) were independent prognostic factors for DFS. The RAS-Beppu classification showed higher hazard ratios than the Beppu classification, as well as the genetic and morphological evaluation score and the modified clinical risk score, which include the RAS status. The hazard ratios in the RAS-Beppu classification were significant in all two-group comparisons (2.22 for moderate vs. low, 3.48 for high vs. low, and 1.70 for high vs. moderate). The multivariate analysis of OS showed benefits of the RAS-Beppu classification in the high- vs. low-risk and high- vs. moderate-risk comparisons. Conclusions: The RAS-Beppu classification using standard parameters is a novel suitable tool for predicting recurrence risk before liver resection.

CEA Rebound After Discontinuation of Pre-Hepatectomy Chemotherapy Predicts Worse Outcomes After Resection of Colorectal Cancer Liver Metastases

BACKGROUND

Carcinoembryonic antigen (CEA) levels may vary with administration and discontinuation of pre-hepatectomy chemotherapy in patients undergoing resection of colorectal cancer liver metastases (CLM). The prognostic significance of these changes, termed CEA dynamics, is unclear.

PATIENTS AND METHODS

Consecutive patients undergoing hepatectomy for CLM (2001-2021) at a comprehensive cancer center were included. CEA dynamics were classified as CEA normal (CEA < 5 ng/mL before, during, and after chemotherapy), CEA decrease (elevated CEA levels that drop during and after chemotherapy), and CEA rebound (elevated CEA levels that drop during chemotherapy but rebound upon discontinuation). Recurrence-free (RFS), hepatic-specific disease-free (hDFS), and overall survival (OS) were compared across CEA dynamics groups.

RESULTS

Of 903 patients, 254 (28%) were CEA normal, 423 (47%) were CEA decrease, and 226 (25%) were CEA rebound. Median RFS was 15.9 months, median hDFS was not reached, and median OS was 11.9 years for CEA normal patients. By comparison, CEA decrease and CEA rebound patients had shorter median RFS (12.2 months, P = 0.002 and 7.4 months, P < 0.001, respectively), shorter median hDFS (29.1 months, P = 0.003 and 14.8 months, P < 0.001, respectively), and shorter median OS (7.1 years, P = 0.131, and 4.9 years, P < 0.001, respectively). On multivariable analysis, CEA rebound was an independent predictor of worse RFS [hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.16-1.93], hDFS (HR 1.39, 95% CI 1.03-1.88), and OS (HR 1.79, 95% CI 1.18-2.73). Among patients with CEA rebound, RAS-BRAF/TP53 comutation and multiple tumors predicted worse OS while APC mutation predicted improved OS.

CONCLUSION

CEA rebound between pre-hepatectomy chemotherapy discontinuation and CLM resection is associated with worse oncologic outcomes, particularly in patients with aggressive tumor biology, and may help frame patient and surgeon expectations ahead of CLM resection.

Circulating Tumor DNA Predicts Early Recurrence Following Locoregional Therapy for Oligometastatic Colorectal Cancer

(1) Background: Local therapies offer a potentially curative approach for patients with oligometastatic colorectal cancer (CRC). An evidence-based consensus recommendation for systemic therapy following definitive locoregional therapy is lacking. Tumor-informed circulating tumor DNA (ctDNA) might provide information to help guide management in this setting. (2) Methods: A multi-institutional retrospective study was conducted, including patients with CRC that underwent curative-intent locoregional therapy to an isolated site of metastatic disease, followed by tumor-informed ctDNA assessment. The Kaplan-Meier method and log-rank tests were used to compare disease-free survival based on ctDNA results. ctDNA test performance was compared to carcinoembryonic antigen (CEA) test results using McNemar's test. (3) Results: Our study cohort consisted of 87 patients treated with locoregional interventions who underwent ctDNA testing. The initial ctDNA test post-intervention was positive in 28 patients and negative in 59 patients. The median follow-up time was 14.0 months. Detectable ctDNA post-intervention was significantly associated with early disease recurrence, with a median disease-free survival (DFS) of 6.63 months compared to 21.30 months in ctDNA-negative patients (p < 0.001). ctDNA detected a numerically higher proportion of recurrences than CEA (p < 0.097). Post-intervention systemic therapy was not associated with improved DFS (p = 0.745). (4) Conclusions: ctDNA results are prognostically important in oligometastatic CRC, and further prospective studies are urgently needed to define its role in guiding clinical decisions.

Evolving survival gains in patients with young-onset colorectal cancer and synchronous resectable liver metastases

We aimed to evaluate the practice and the associated outcomes of surgical treatment for young-onset colorectal cancer (YOCRC) patients presenting with synchronous liver metastases. The study cohort was divided into two groups according to surgery date: 131 patients in the early era (EE, 1998-2011) and 179 in the contemporary era (CE, 2012-2020). The CE had a higher rate of node-positive primary tumors, higher carcinoembryonic antigen level, and lower rate of RAS/BRAF mutations. The CE had higher rates of reverse or combined resection, multi-drug prehepatectomy chemotherapy, and two-stage hepatectomy. The median survival was 8.4 years in the CE and 4.3 years in the EE (p = 0.011). On multivariate analysis, hepatectomy in the CE was independently associated with improved overall survival (HR 0.48, p = 0.001). With a combination of perioperative systemic therapy, careful selection of treatment approach, and coordinated resections, durable cure can be achieved in YOCRC patients.