Association of KRAS Variant Subtypes With Survival and Recurrence in Patients With Surgically Treated Intrahepatic Cholangiocarcinoma

Racial and Sex Differences in Genomic Profiling of Intrahepatic Cholangiocarcinoma

BACKGROUND

Racial and sex disparities in the incidence and outcomes of patients with intrahepatic cholangiocarcinoma (iCCA) exist, yet potential genomic variations of iCCA based on race and sex that might be contributing to disparate outcomes have not been well studied.

METHODS

Data from the American Association for Cancer Research Project GENIE registry (version 15.0) were analyzed to assess genetic variations in iCCA. Adult patients (age >18 years) with histologically confirmed iCCA who underwent next-generation sequencing were included in the analytic cohort. Racial and sex variations in genomic profiling of iCCA were examined.

RESULTS

The study enrolled 1068 patients from 19 centers (White, 71.9%; Black, 5.1%; Asian, 8.4%, other, 14.6%). The male-to-female ratio was 1:1. The majority of the patients had primary tumors (73.7%), whereas 23.0% had metastatic disease sequenced. While IDH1 mutations occurred more frequently in White versus Black patients (20.8% vs. 5.6%; p = 0.021), FGFR2 mutations tended to be more common among Black versus White populations (27.8% vs. 16.1%; p = 0.08). Males were more likely to have TP53 mutations than females (24.3% vs. 18.2%, p = 0.016), whereas females more frequently had IDH1 (23.3% vs 16.0 %), FGFR2 (21.0% vs. 11.3%), and BAP1 (23.4% vs. 14.5%) mutations than males (all p < 0.05). Marked variations in the prevalence of other common genomic alterations in iCCA were noted across different races and sexes.

CONCLUSION

Distinct genomic variations exist in iCCA across race and sex. Differences in mutational profiles of iCCA patients highlight the importance of including a diverse patient population in iCCA clinical trials as well as the importance of recognizing different genetic drivers that may be targetable to treat distinct patient cohorts.

Characterization of tumor microbiome and associations with prognosis in intrahepatic cholangiocarcinoma

BACKGROUND

The tumor microbiome has been characterized in several malignancies; however, no previous studies have investigated its role in intrahepatic cholangiocarcinoma (ICC). Hence, we explored the tumor microbiome and its association with prognosis in ICC.

METHODS

One hundred and twenty-one ICC tumor samples and 89 adjacent normal tissues were profiled by 16S rRNA sequencing. Microbial differences between tumor and adjacent nontumoral liver tissues were assessed. Tumor microbial composition was then evaluated to detect its association with prognosis. Finally, a risk score calculated by the tumor microbiota was accessed by the least absolute shrinkage and selector operator method (Lasso) to predict prognosis of ICC.

RESULTS

The tumor microbiome displayed a greater diversity than that in adjacent nontumoral liver tissues. Tumor samples were characterized by a higher abundance of Firmicutes, Actinobacteria, Bacteroidetes, and Acidobacteriota. Higher tumor microbial α diversity was associated with lymph node metastasis and predicted shortened overall survival (OS) and recurrence-free survival (RFS). A total of 11 bacteria were selected to generate the risk score by Lasso. This score showed potential in predicting OS, and was an independent risk factor for OS.

CONCLUSION

In conclusion, our study characterized the tumor microbiome and revealed its role in predicting prognosis in ICC.

KRAS Allelic Variants in Biliary Tract Cancers

Importance

Biliary tract cancers (BTCs) contain several actionable molecular alterations, including FGFR2, IDH1, ERBB2 (formerly HER2), and KRAS. KRAS allelic variants are found in 20% to 30% of BTCs, and multiple KRAS inhibitors are currently under clinical investigation.

Objectives

To describe the genomic landscape, co-sequence variations, immunophenotype, genomic ancestry, and survival outcomes of KRAS-mutated BTCs and to calculate the median overall survival (mOS) for the most common allelic variants.

Design, Setting, and Participants

This retrospective, multicenter, pooled cohort study obtained clinical and next-generation sequencing data from multiple databases between January 1, 2017, and December 31, 2022. These databases included Princess Margaret Cancer Centre, MD Anderson Cancer Center, Foundation Medicine, American Association for Cancer Research Project GENIE, and cBioPortal for Cancer Genomics. The cohort comprised patients with BTCs who underwent genomic testing.

Main Outcome and Measure

The main outcome was mOS, defined as date of diagnosis to date of death, which was measured in months.

Results

A total of 7457 patients (n = 3773 males [50.6%]; mean [SD] age, 63 [5] years) with BTCs and genomic testing were included. Of these patients, 5813 had clinical outcome data available, in whom 1000 KRAS-mutated BTCs were identified. KRAS allelic variants were highly prevalent in perihilar cholangiocarcinoma (28.6%) and extrahepatic cholangiocarcinoma (36.1%). Thirty-six KRAS allelic variants were identified, and the prevalence rates in descending order were G12D (41%), G12V (23%), and Q61H (8%). The variant G12D had the highest mOS of 25.1 (95% CI, 22.0-33.0) months compared with 22.8 (95% CI, 19.6-31.4) months for Q61H and 17.8 (95% CI, 16.3-23.1) months for G12V variants. The majority of KRAS-mutated BTCs (98.9%) were not microsatellite instability-high and had low tumor mutational burden (ranging from a median [IQR] of 1.2 (1.2-2.5) to a mean [SD] of 3.3 [1.3]). Immune profiling through RNA sequencing of KRAS and NRAS-mutated samples showed a pattern toward a more immune-inflamed microenvironment with higher M1 macrophage activation (0.16 vs 0.12; P = .047) and interferon-γ expression compared with wild-type tumors. The G12D variant remained the most common KRAS allelic variant in all patient ancestries. Patients with admixed American ancestry had the highest proportion of G12D variant (45.0%).

Conclusions and Relevance

This cohort study found that KRAS allelic variants were relatively common and may be potentially actionable genomic alterations in patients with BTCs, especially perihilar cholangiocarcinoma and extrahepatic cholangiocarcinoma. The findings add to the growing data on genomic and immune landscapes of KRAS allelic variants in BTCs and are potentially of value to the planning of specific therapies for this heterogeneous patient group.

Reclassification of RAS/BRAF allele mutations predicts the survival benefit of triplet chemotherapy in metastatic colorectal cancer

Background

Different RAS/BRAF allele mutations imply distinct biological properties in various solid tumors. Recently, several studies have focused on the predictive and prognostic roles of various RAS/BRAF allele mutations in colorectal cancer (CRC) but the results remain controversial.

Methods

Between March 2017 and September 2022, the patients diagnosed as stages I-IV CRC with detailed medical records including next-generation sequencing (NGS) data and clinicopathological follow-up information available at our center were enrolled. Survival data were estimated using the Kaplan-Meier method, and the difference was tested in a log-rank test. Multivariate tests were carried out using Cox models.

Results

A total of 1029 CRC patients were included, and the incidence of RAS/BRAF mutation was 58.4%. The hypermutated cohort was defined as patients with microsatellite instability-H or POLE/D mutation. In the non-hypermutational cohort, only KRAS G13D mutation was associated with a higher incidence and inferior disease-free survival in patients with stage I-III CRC. In the cohort of patients with non-hypermutated metastatic colorectal cancer (mCRC), we assessed the risk of various RAS/BRAF allele mutations and subsequently reclassified patients into four groups based on first-line median progression-free survival: wild type (group 1), low-risk RAS/BRAF mutation (group 2, RAS/BRAF mutations other than KRAS G13D/G12V/G12C or BRAF V600E), high-risk RAS mutation (group 3, KRAS G13D/G12V/G12C), and BRAF V600E mutation (group 4). mCRC patients with high-risk RAS mutation could significantly benefit from intensive triplet chemotherapy (hazard ratio, 2.54; 95% confidence interval, 1.36-5.12; p = 0.0091).

Conclusion

In the non-hypermutated CRC cohort, the prognostic risk of various RAS/BRAF allele mutations varied between local and metastatic CRC. KRAS G13D mutation tended to be the only prognostic marker for stages I-III CRC; however, KRAS G13D/G12V/G12C mutations collectively defined a high-risk subgroup of mCRC patients with poor prognosis, who would benefit from intensive triplet chemotherapy.

Targeting KRAS-Mutated Gastrointestinal Malignancies with Small-Molecule Inhibitors: A New Generation of Breakthrough Therapies

Kirsten rat sarcoma virus (KRAS) is one of the most important and frequently mutated oncogenes in cancer and the mutational prevalence is especially high in many gastrointestinal malignancies, including colorectal cancer and pancreatic ductal adenocarcinoma. The KRAS protein is a small GTPase that functions as an "on/off" switch to activate downstream signaling, mainly through the mitogen-activated protein kinase pathway. KRAS was previously considered undruggable because of biochemical constraints; however, recent breakthroughs have enabled the development of small-molecule inhibitors of KRAS G12C. These drugs were initially approved in lung cancer and have now shown substantial clinical activity in KRAS G12C-mutated pancreatic ductal adenocarcinoma as well as colorectal cancer when combined with anti-EGFR monoclonal antibodies. Early data are encouraging for other gastrointestinal cancers as well and many other combination strategies are being investigated. Several new KRAS G12C inhibitors and novel inhibitors of other KRAS alterations have recently entered the clinic. These molecules employ a variety of innovative mechanisms and have generated intense interest. These novel drugs are especially important as KRAS G12C is rare in gastrointestinal malignancies compared with other KRAS alterations, representing potentially groundbreaking advances. Soon, the rapidly evolving landscape of novel KRAS inhibitors may substantially shift the therapeutic landscape for gastrointestinal cancers and offer meaningful survival improvements.

Development and validation of a mutation-annotated prognostic score for intrahepatic cholangiocarcinoma after resection: a retrospective cohort study

BACKGROUND

The value of existing prognostic models for intrahepatic cholangiocarcinoma is limited. The inclusion of prognostic gene mutations would enhance the predictive efficacy.

METHODS

In the screening cohorts, univariable Cox regression analysis was applied to investigate the effect of individual mutant genes on overall survival (OS). In the training set, multivariable analysis was performed to evaluate the independent prognostic roles of the clinicopathological and mutational parameters, and a prognostic model was constructed. Internal and external validations were conducted to evaluate the performance of this model.

RESULTS

Among the recurrent mutations, only TP53 and KRASG12 were significantly associated with OS across all three screening cohorts. In the training cohort, TP53 and KRASG12 mutations in combination with seven other clinical parameters (tumor size, tumor number, vascular invasion, lymph node metastasis, adjacent invasion, CA19-9, and CEA), were independent prognostic factors for OS. A mutation-annotated prognostic score (MAPS) was established based on the nine prognosticators. The C-indices of MAPS (0.782 and 0.731 in the internal and external validation cohorts, respectively) were statistically higher than those of other existing models ( P <0.05). Furthermore, the MAPS model also demonstrated significant value in predicting the possible benefits of upfront surgery and adjuvant therapy.

CONCLUSIONS

The MAPS model demonstrated good performance in predicting the OS of intrahepatic cholangiocarcinoma patients. It may also help predict the possible benefits of upfront surgery and adjuvant therapy.

New Era of Immune-Based Therapy in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (CC) accounts for approximately 20% of all biliary tract cancer (BTC) cases and 10-15% of all primary liver cancer cases. Many patients are diagnosed with unresectable BTC, and, even among patients with resectable BTC, the 5-year survival rate is approximately 20%. The BTC incidence rate is high in Southeast and East Asia and has increased worldwide in recent years. Since 2010, cytotoxic chemotherapy, particularly combination gemcitabine + cisplatin (ABC-02 trial), has been the first-line therapy for patients with BTC. In 2022, a multicenter, double-blind, randomized phase 3 trial (TOPAZ-1 trial) examined the addition of programmed death-ligand 1 immunotherapy (durvalumab) to combination gemcitabine + cisplatin for BTC treatment, resulting in significantly improved survival without notable additional toxicity. As a result of this trial, this three-drug combination has become the new standard first-line therapy, leading to notable advances in BTC management for the first time since 2010. The molecular profiling of BTC has continued to drive the development of new targeted therapies for use when first-line therapies fail. Typically, second-line therapy decisions are based on identified genomic alterations in tumor tissue. Mutations in fibroblast growth factor receptor 1/2/3, isocitrate dehydrogenase 1/2, and neurotrophic tyrosine receptor kinase A/B/C are relatively frequent in intrahepatic CC, and precision medicines are available that can target associated pathways. In this review, we suggest strategies for systemic pharmacotherapy with a focus on intrahepatic CC, in addition to presenting the results and safety outcomes of clinical trials evaluating immune checkpoint inhibitor therapies in BTC.

Advances in the treatment of intrahepatic cholangiocarcinoma: An overview of the current and future therapeutic landscape for clinicians

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver tumor and remains a fatal malignancy in the majority of patients. Approximately 20%-30% of patients are eligible for resection, which is considered the only potentially curative treatment; and, after resection, a median survival of 53 months has been reported when sequenced with adjuvant capecitabine. For the 70%-80% of patients who present with locally unresectable or distant metastatic disease, systemic therapy may delay progression, but survival remains limited to approximately 1 year. For the past decade, doublet chemotherapy with gemcitabine and cisplatin has been considered the most effective first-line regimen, but results from the recent use of triplet regimens and even immunotherapy may shift the paradigm. More effective treatment strategies, including those that combine systemic therapy with locoregional therapies like radioembolization or hepatic artery infusion, have also been developed. Molecular therapies, including those that target fibroblast growth factor receptor and isocitrate dehydrogenase, have recently received US Food and Drug Administration approval for a defined role as second-line treatment for up to 40% of patients harboring these actionable genomic alterations, and whether they should be considered in the first-line setting is under investigation. Furthermore, as the oncology field seeks to expand indications for immunotherapy, recent data demonstrated that combining durvalumab with standard cytotoxic therapy improved survival in patients with ICC. This review focuses on the current and future strategies for ICC treatment, including a summary of the primary literature for each treatment modality and an algorithm that can be used to drive a personalized and multidisciplinary approach for patients with this challenging malignancy.

Association of BRAF Variants With Disease Characteristics, Prognosis, and Targeted Therapy Response in Intrahepatic Cholangiocarcinoma

IMPORTANCE

BRAF variants are associated with tumor progression; however, the prevalence of BRAF variant subtypes and their association with disease characteristics, prognosis, and targeted therapy response in patients with intrahepatic cholangiocarcinoma (ICC) are largely unknown.

OBJECTIVE

To explore the association of BRAF variant subtypes with disease characteristics, prognosis, and targeted therapy response in patients with ICC.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, 1175 patients who underwent curative resection for ICC from January 1, 2009, through December 31, 2017, were evaluated at a single hospital in China. Whole-exome sequencing, targeted sequencing, and Sanger sequencing were performed to identify BRAF variants. The Kaplan-Meier method and log-rank test were used to compare overall survival (OS) and disease-free survival (DFS). Univariate and multivariate analyses were performed using Cox proportional hazards regression. Associations between BRAF variants and targeted therapy response were tested in 6 BRAF-variant, patient-derived organoid lines and in 3 of the patient donors of those lines. Data were analyzed from June 1, 2021, to March 15, 2022.

INTERVENTIONS

Hepatectomy in patients with ICC.

MAIN OUTCOMES AND MEASURES

The association of BRAF variant subtypes with OS and DFS.

RESULTS

Of 1175 patients with ICC, the mean (SD) age was 59.4 (10.4) years and 701 (59.7%) were men. A total of 20 different subtypes of BRAF somatic variance affecting 49 patients (4.2%) were identified; V600E was the most frequent allele in this cohort, accounting for 27% of the identified BRAF variants, followed by K601E (14%), D594G (12%), and N581S (6%). Compared with patients with non-V600E BRAF variants, patients with BRAF V600E variants were more likely to have large tumor size (10 of 13 [77%] vs 12 of 36 [33%]; P = .007), multiple tumors (7 of 13 [54%] vs 8 of 36 [22%]; P = .04), and more vascular/bile duct invasion (7 of 13 [54%] vs 8 of 36 [22%]; P = .04). Multivariate analysis revealed that BRAF V600E variants, but not overall BRAF variants or non-V600E BRAF variants, were associated with poor OS (hazard ratio [HR], 1.87; 95% CI, 1.05-3.33; P = .03) and DFS (HR, 1.66; 95% CI, 1.03-2.97; P = .04). There were also broad differences among organoids with different BRAF variant subtypes in sensitivity to BRAF or MEK inhibitors.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that there are broad differences among organoids with different BRAF variant subtypes in sensitivity to BRAF or MEK inhibitors. Identifying and classifying BRAF variants may be able to help guide precise treatment for patients with ICC.

The clinical implications and molecular features of intrahepatic cholangiocarcinoma with perineural invasion

BACKGROUND

Perineural invasion (PNI) is associated with metastasis in malignancies, including intrahepatic cholangiocarcinoma (ICC), and is correlated with poor prognosis.

METHODS

The study included three large cohorts: ZS-ICC and TMA cohorts from our team, MSK cohort from a public database, and a small cohort named cohort 4. Prognostic implications of PNI were investigated in MSK cohort and TMA cohort. PNI-related genomic and transcriptomic profiles were analyzed in MSK and ZS-ICC cohorts. GO, KEGG, and ssGSEA analyses were performed. Immunohistochemistry was used to investigate the relationship between PNI and markers of neurons, hydrolases, and immune cells. The efficacy of adjuvant therapy in ICC patients with PNI was also assessed.

RESULTS

A total of 30.6% and 20.7% ICC patients had PNI in MSK and TMA cohorts respectively. Patients with PNI presented with malignant phenotypes such as high CA19-9, the large bile duct type, lymph node invasion, and shortened overall survival (OS) and relapse-free survival (RFS). Nerves involved in PNI positively express tyrosine hydroxylase (TH), a marker of sympathetic nerves. Patients with PNI showed high mutation frequency of KRAS and an immune suppressive metastasis prone niche of decreased NK cell, increased neutrophil, and elevated PD-L1, CD80, and CD86 expression. Patients with PNI had an extended OS after adjuvant therapy with TEGIO, GEMOX, or capecitabine.

CONCLUSION

Our study deciphered the genomic features and the immune suppressive metastasis-prone niche in ICC with PNI. Patients with PNI showed a poor prognosis after surgery but a good response to adjuvant chemotherapy.

Label-Free Imaging Analysis of Patient-Derived Cholangiocarcinoma Organoids after Sorafenib Treatment

Monitoring tumor growth dynamics is crucial for understanding cancer. To establish an in vitro method for the continuous assessment of patient-specific tumor growth, tumor organoids were generated from patients with intrahepatic CCA (iCCA). Organoid growth was monitored for 48 h by label-free live brightfield imaging. Growth kinetics were calculated and validated by MTS assay as well as immunohistochemistry of Ki67 to determine proliferation rates. We exposed iCCA organoids (iCCAOs) and non-tumor intrahepatic cholangiocyte organoids (ICOs) to sub-therapeutic concentrations of sorafenib. Monitoring the expansion rate of iCCAOs and ICOs revealed that iCCAO growth was inhibited by sorafenib in a time- and dose-dependent fashion, while ICOs were unaffected. Quantification of the proliferation marker Ki67 confirmed inhibition of iCCAO growth by roughly 50% after 48 h of treatment with 4 µM sorafenib. We established a robust analysis pipeline combining brightfield microscopy and a straightforward image processing approach for the label-free growth monitoring of patient-derived iCCAOs. Combined with bioanalytical validation, this approach is suitable for a fast and efficient high-throughput drug screening in tumor organoids to develop patient-specific systemic treatment options.

Identification of macrophage correlated biomarkers to predict the prognosis in patients with intrahepatic cholangiocarcinoma

Background

It has been shown that tumor-associated immune cells, particularly macrophages, play a fundamental role in the development and treatment response of intrahepatic cholangiocarcinoma (ICC). However, little is known about macrophages at the single cellular level of ICC patients.

Methods

ScRNA-seq from Zhang et al. was used in the present study to identify the genes differentially expressed in ICCs. Furthermore, transcriptomic data from TCGA datasets, IHC and flowcytometry from our cohort were used to confirm the findings. Kaplan-Meier and TIDE scores were also used for prognostic analysis and ICB responses.

Results

A significant number of macrophages were found in ICCs as compared to adjacent tissues. We then extracted, processed, and classified the macrophages from the ICCs and adjacent tissues into 12 clusters. Significantly, the macrophages from the ICC exhibited an immunosuppressed state in terms of both signature gene expression and functional enrichment. Furthermore, our results indicate that, of the 10 selective tumor-promoting genes of macrophages, only MMP19 and SIRPα can predict ICB responses in ICCs. Although a higher expression of MMP19 and SIRPα predict a poor prognosis for ICCs without immunotherapy after surgery, patients with high SIRPα expression were more sensitive to immunotherapy, whereas those with high MMP19 expression were not sensitive to immunotherapy. To define the mechanisms, we found that SIRPα^hi ICCs exhibited an increased enrichment KEGG pathway of leukocyte transendothelial migration and neutrophil extracellular trap formation. The increased immune cell infiltration will increase sensitivity to immunotherapy.

Conclusion

Collectively, macrophages are critical to the immune status of ICCs, and MMP19 and SIRPα can predict prognosis and ICB responses for ICCs.

Clinical relevance of biomarkers in cholangiocarcinoma: critical revision and future directions

Cholangiocarcinoma (CCA) is a malignant tumour arising from the biliary system. In Europe, this tumour frequently presents as a sporadic cancer in patients without defined risk factors and is usually diagnosed at advanced stages with a consequent poor prognosis. Therefore, the identification of biomarkers represents an utmost need for patients with CCA. Numerous studies proposed a wide spectrum of biomarkers at tissue and molecular levels. With the present paper, a multidisciplinary group of experts within the European Network for the Study of Cholangiocarcinoma discusses the clinical role of tissue biomarkers and provides a selection based on their current relevance and potential applications in the framework of CCA. Recent advances are proposed by dividing biomarkers based on their potential role in diagnosis, prognosis and therapy response. Limitations of current biomarkers are also identified, together with specific promising areas (ie, artificial intelligence, patient-derived organoids, targeted therapy) where research should be focused to develop future biomarkers.

The path to personalized treatment in advanced and metastatic biliary tract cancers: a review of new targeted therapies and immunotherapy

PURPOSE OF REVIEW

To summarize targeted therapies and immunotherapy as treatment for advanced/metastatic biliary tract cancers and discuss ongoing clinical trials.

RECENT FINDINGS

For the first time since gemcitabine-cisplatin was set as the standard of care in first-line advanced/metastatic biliary tract cancers in the ABC-02 trial, the combination of durvalumab and gemcitabine-cisplatin has demonstrated a statistically significant improvement of median overall survival in the TOPAZ-1 phase 3 trial. The ABC-06 trial showed a significant increase of median overall survival for FOLFOX and active symptom control compared with active symptom control alone in second-line regardless of molecular and genetic alterations. However, faced with a heterogeneous cancer, patient prognosis remains poor, leaving room for new, personalized, treatment options such as targeted therapies. Efficacy of fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors has been demonstrated in different phase 2 trials for previously treated intrahepatic cholangiocarcinomas harboring FGFR2 fusions. Ivosidenib increases significantly median progression-free survival in previously treated cholangiocarcinomas with isocitrate dehydrogenase-1 (IDH-1) mutation. Other targeted therapies are tested for tumors with HER2 amplifications/mutations, BRAFV600E mutations or KRASG12C mutations.

SUMMARY

In this review, we aim to follow the changes in the treatment of these tumors, moving from very few chemotherapy options to immunotherapy and targeted therapies in the context of molecular selection of biliary tract cancers subtypes.

The impact of molecular and mismatch repair status on the survival outcomes of surgically treated patients with colorectal peritoneal metastases

BACKGROUND

Stratification of patients with colorectal peritoneal metastases (CRPM) using RAS/BRAF mutational status may refine patient selection for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). This study aimed to analyse the association of RAS/BRAF status and their variants, with clinicopathological variables and survival outcomes in patients who have undergone CRS ± HIPEC.

METHODS

A single centre, peritonectomy database was interrogated for patients with CRPM who underwent peritonectomy procedures between 2010 and 2020.

RESULTS

During the study period, 174 patients were included. Molecular status was obtained on 169 patients, with 68 (40.5%) KRAS, 25 (14.8%) BRAF and 6 (3.6%) NRAS mutations detected. Patients with BRAF mutations were more likely to be mismatch repair deficient (dMMR) (BRAF 20%, KRAS 4.4%, wild type 8.6%, p = 0.015). Most common BRAF and KRAS variants were, V600E (80%) and G12D (39.7%), respectively. BRAF V600E was independently associated with worse overall (median: 28 months, multivariate: HR 2.29, p = 0.026) and disease-free survival (median: 8 months, multivariate: HR 1.8, p = 0.047). KRAS G12V was a strong prognostic factor associated with disease-free survival (median: 9 months, HR 2.63, p = 0.016). dMMR patients (14/161, 8.7%) exhibited worse median overall survival compared to those with proficient MMR (dMMR 27 months, pMMR 29 months p = 0.025).

CONCLUSION

This study highlights the importance of molecular analysis in CRPM stratification. BRAF V600E mutations predict poor outcomes post CRS and HIPEC and may help refine patient selection for this procedure. Molecular analysis should be performed preoperatively to characterise prognosis and guide perioperative therapeutic options.