Association of RAS Mutation Location and Oncologic Outcomes After Resection of Colorectal Liver Metastases

Genetic Clustering of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Patients of Colorectal Origin: KRAS and Not TP53 Cluster Alterations are Associated with Poor Outcomes

BACKGROUND

The prognostic impact of genetic mutations for patients who undergo cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) of colorectal origin (CRC) is not well defined.

OBJECTIVE

We aimed to describe the genetic classifications in an unsupervised fashion, and the outcomes of this patient population.

METHODS

A retrospective, bi-institutional study was performed on patients who underwent CRS-HIPEC with targeted mutation data with a median follow-up time of 61 months. Functional link analysis was performed using STRING v11.5. Genes with similar functional significance were clustered using unsupervised k-means clustering. Chi-square, Kaplan-Meier, and the log-rank test were used for comparative statistics.

RESULTS

Sixty-four patients with peritoneal carcinomatosis from CRC origin underwent CRS-HIPEC between 2007 and 2022 and genetic mutation data were extracted. We identified 19 unique altered genes, with KRAS (56%), TP53 (33%), and APC (22%) being the most commonly altered; 12.5% had co-altered KRAS/TP53. After creating an interactome map, k-means clustering revealed three functional clusters. Reactome Pathway analysis on three clusters showed unique pathways (1): Ras/FGFR3 signaling; (2) p53 signaling; and (3): NOTCH signaling. Seventy-one percent of patients in cluster 1 had KRAS mutations and a median overall survival of 52.3 months (p < 0.05).

CONCLUSIONS

Patients with peritoneal carcinomatosis (PC) of CRC origin who underwent CRS-HIPEC and with tumors that harbored mutations in cluster 1 (Ras/FGFR3 signaling) had worse outcomes. Pathway disruption and a cluster-centric perspective may affect prognosis more than individual genetic alterations in patients with PC of CRC origin.

RAS Mutations Predict Recurrence-Free Survival and Recurrence Patterns in Colon Cancer: A Unicenter Study in Morocco

PURPOSE

To date, only a few studies have investigated the role of molecular alterations in cancer recurrence. This exploratory study aimed to evaluate the impact of molecular alterations on the time and site of recurrence in patients with stage I-IV CRC and to identify the risk factors predicting recurrence-free survival in colon cancer.

METHODS

A total of 270 patients were retrospectively included. We assessed the full RAS status using Sanger and pyrosequencing. MSI status was determined by immunohistochemical analysis. Molecular alterations were correlated with recurrence timing (early or late), recurrence patterns, and recurrence-free survival. Statistical analysis was performed using the Kaplan-Meier method and the log-rank test.

RESULTS

Of the 270 patients, 85 (31%) experienced recurrence, among whom 53% had mutant full RAS status, 48% had KRAS mutations, and 31.4% had KRAS p. G12V mutation subtype. Compared with those with late recurrence, patients with early recurrence were significantly older (P = 0.02) and more likely to have poorly differentiated tumors, a higher rate of positive lymph nodes, KRAS mutations, and especially KRAS p. G12V mutation variant. RAS mutation status, KRAS mutations, and rare mutations are more common in patients with lung cancer recurrence. Multivariate logistic regression analysis revealed that differentiation, perineural invasion, full RAS mutation status, and KRAS codon 13 mutations were independent factors for recurrence-free survival in colon cancer.

CONCLUSION

In this cohort, the timing and patterns of recurrence appeared to be associated with the patient's molecular profile. KRAS codon 12 mutations were the worst predictors of recurrence-free survival at all stages in our population.

Does RAS Status Increase the Prevalence of Positive Resection Margin in Colorectal Liver Metastasis? A Systematic Review and Meta-Analysis

BACKGROUND

Colorectal liver metastasis has a high incidence, and RAS oncogene mutation status carries significant prognostic information. We aimed to assess whether RAS-mutated patients present more or less frequently with positive margins in their hepatic metastasectomy.

METHODS

We performed a systematic review and meta-analysis of studies from PubMed, Embase, and Lilacs databases. We analyzed liver metastatic colorectal cancer studies, which included information on RAS status and had surgical margin analysis of the liver metastasis. Odds ratios were computed using a random-effect model due to anticipated heterogeneity. We further performed a subanalysis limited to studies that included only patients with KRAS instead of all-RAS mutations.

RESULTS

From the 2,705 studies screened, 19 articles were included in the meta-analysis. There were 7,391 patients. The prevalence of positive resection margin was not significantly different between patients carrier vs non-carrier for the all-RAS mutations (OR .99; 95% CI 0.83-1.18; P = .87), and for only KRAS mutation (OR .93; 95% CI 0.73-1.19; P = .57).

CONCLUSIONS

Despite the strong correlation between colorectal liver metastasis prognosis and RAS mutation status, our meta-analysis's results suggest no correlation between the RAS status and the prevalence of positive resection margins. The findings contribute to a better understanding of the RAS mutation's role in the surgical resections of colorectal liver metastasis.

Implications of RAS Mutations on Oncological Outcomes of Surgical Resection and Thermal Ablation Techniques in the Treatment of Colorectal Liver Metastases

Simple Summary

Modern management of colorectal liver metastases (CRLM) requires a thorough knowledge of tumor biology and oncogenes mutations. RAS mutations are of paramount interest for the indication of targeted therapies and is increasingly considered as a negative prognostic factor for patients undergoing surgical resection or ablation for CRLM. Several studies discussed the results of specific technical considerations according to RAS mutational status on the oncological outcomes after surgical resection/ablation for CRLM. We reviewed the available data on the real impact of RAS mutations on the prognosis with special regard to the need of a tailored surgical (ablation) approach according to tumoral biology.

Abstract

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. More than 50% of patients with CRC will develop liver metastases (CRLM) during their disease. In the era of precision surgery for CRLM, several advances have been made in the multimodal management of this disease. Surgical treatment, combined with a modern chemotherapy regimen and targeted therapies, is the only potential curative treatment. Unfortunately, 70% of patients treated for CRLM experience recurrence. RAS mutations are associated with worse overall and recurrence-free survival. Other mutations such as BRAF, associated RAS /TP53 and APC/PIK3CA mutations are important genetic markers to evaluate tumor biology. Somatic mutations are of paramount interest for tailoring preoperative treatment, defining a surgical resection strategy and the indication for ablation techniques. Herein, the most relevant studies dealing with RAS mutations and the management of CRLM were reviewed. Controversies about the implication of this mutation in surgical and ablative treatments were also discussed.

Molecular Determinants and Other Factors to Guide Selection of Patients for Hepatic Resection of Metastatic Colorectal Cancer

OPINION STATEMENT

Treatment for metastatic colorectal cancer (CRC) has changed significantly over the last few decades as cytotoxic and targeted chemotherapies have evolved and resection of (technically feasible) colorectal liver metastases (CRLM) has become standard of care for eligible patients. Overall, survival for metastatic CRC has considerably improved, but recurrences are common. Numerous clinical risk scores have been suggested to guide patient selection for CRLM resection, but none perfectly predict outcomes; therefore, a personalized approach to metastatic CRC treatment using genetic profiles for risk stratification and prognostication is a critically important advancement. All patients with suspected metastatic CRC should undergo genetic testing for common oncogene mutations (e.g., KRAS, BRAF, and NRAS) in addition to a triphasic CT scan of the chest, abdomen, and pelvis; if hepatectomy may be entertained and there is concern about the future liver remnant (FLR), liver volumetrics should also be performed. MRI and PET are useful adjuncts for cases in which diagnosis or extent of disease is unclear. The decision to operate should be individualized and based on each patient's condition, tumor biology, and technical resectability. Genetic profiles should be used to inform multidisciplinary meetings surrounding topics of chemotherapy and surgical resection, as well as patient discussions concerning the risks and benefits of surgery. In the end, most patients with technically resectable colorectal cancers and adequate cardiopulmonary fitness benefit from surgical resection, as it remains the only chance of long-term survival.