Evolution of Rapid Clonal Dynamics and Non-Cross-Resistance in Response to Alternating Targeted Therapy and Chemotherapy in BRAF-V600E-Mutant Colon Cancer.

Purpose: Combined BRAF, MEK, and EGFR inhibition can induce clinical responses in BRAF-V600E-mutant colon cancer, but rapid resistance often occurs.

Methods: We use serial monitoring of circulating tumor DNA cell-free plasma DNA (cfDNA) in a patient case study in addition to organoids derived from mouse models of BRAF-V600E-mutant intestinal cancer, which emulated the patient's mutational profile to assess drug treatment efficacy.

Results: We demonstrate dynamic evolution of resistance to combined EGFR/BRAF/MEK inhibition in a pediatric patient with metastatic BRAF-V600E-mutant, mismatch repair-stable colon cancer.

In Vitro Organoid-Based Assays Reveal SMAD4 Tumor-Suppressive Mechanisms for Serrated Colorectal Cancer Invasion.

Colon cancer is the third most prominent cancer and second leading cause of cancer-related deaths in the United States. Up to 20% of colon cancers follow the serrated tumor pathway driven by mutations in the MAPK pathway. Loss of SMAD4 function occurs in the majority of late-stage colon cancers and is associated with aggressive cancer progression.