Gastrointestinal cancers (GIC), encompassing colonic, rectal, and gastric malignancies, rank among the most prevalent cancer types globally, contributing significantly to cancer-related mortality. In the scientific literature, various syndromes associated with colorectal and gastric cancers have been elucidated, highlighting the intricate interplay between genetic factors and disease manifestation. The primary objective of this study was to conduct a genetic exploration aimed at elucidating these associations and identifying shared genetic determinants across these cancer types. Notably, considerable research has focused on the KRAS gene mutations, polymorphisms in nucleic acids, the Wnt signaling pathway, and the role of chemokine ligands in tumorigenesis. While investigations into natural plant extracts as potential therapeutic agents are still in their nascent stages, they represent a promising avenue for future research. Ongoing studies are essential to uncover suitable biomarkers that could facilitate the identification and understanding of the genetic links between these GIC. This exploration not only seeks to enhance our comprehension of the underlying genetic architecture but also aims to inform the development of targeted therapies and preventive strategies.