Impact of Molecular Status on Cytoreductive Surgery for Peritoneal Metastases from Colorectal Cancer

Impact of RAS, BRAF mutations and microsatellite status in peritoneal metastases from colorectal cancer treated with cytoreduction + HIPEC: scoping review

BACKGROUND

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown survival benefits in select patients with peritoneal metastases (PM) from colorectal cancer (CRC). Molecular alterations, particularly RAS/BRAF mutations and Microsatellite Instability (MSI), play crucial roles in prognostic stratification and treatment planning, influencing both disease-free survival (DFS) and overall survival (OS). This scoping review evaluates the prognostic role of MSI and RAS/BRAF mutations in patients with PM-CRC treated with CRS-HIPEC.

DESIGN

A literature search was conducted across several databases to identify papers published between 2000 and September 2024. We selected 18 publications that considered DFS and OS as primary or secondary outcomes in patients with RAS/BRAF mutations and MSI following CRS-HIPEC treatment. Studies involving appendiceal cancer, peritoneal disease from non-CRC, pediatric patients, or subjects not treated with CRS-HIPEC were excluded.

RESULTS

Most studies suggest that RAS and BRAF mutations have a negative influence on survival outcomes. While inconsistencies exist, RAS mutations are generally associated with worse DFS. Specific KRAS subtypes such as KRASMUT2 or KRAS G12V and the BRAF V600 variant correlate with poorer prognosis. MSI status appears to attenuate the adverse effects of RAS/BRAF mutations on survival, although conflicting data persist.

CONCLUSION

RAS and BRAF mutations correlate with poorer outcomes in PM-CRC, underscoring the need for mutation-informed strategies to refine HIPEC and systemic therapies. Recognizing subtypes may improve patient selection for CRS-HIPEC, optimizing both local disease control and long-term survival. Future research should incorporate these molecular profiles to enhance therapeutic decision-making and better address this challenging condition.

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.