Colorectal cancer is one of the most common cancers worldwide, affecting up to 1.2 billion people a year, causing around 600,000 deaths. Its progression is usually asymptomatic, which often means that the diagnosis is made when metastasis has already developed. The choice of treatment to combat this type of cancer takes into account the characteristics of the tumor, however, obtaining biopsies of the metastatic tissue is usually complicated, and the choice of treatment is finally made based on the analysis of the primary tumor. So, is the characteristics of the primary tumor sufficient to determine treatment?

The teams of Dr. Ramon Salazar and Dr. Alberto Villanueva, from the Bellvitge Biomedical Research Institute (IDIBELL) and the Catalan Institute of Oncology (ICO), have participated in a study, published in the International Journal of Cancer, which has analyzed and compared the gene expression patterns of primary tumors and their respective liver metastases. This type of classification divides tumors into molecular subtypes based on the activation of different biological processes. Up to 82 pairs of tumors have been analyzed, and the results validate the molecular analysis of the primary tumors as an indicator for the choice of treatment. In conclusion, this study highlights that the origin of the tissue may have greater consequences for the precision medicine of colorectal cancer.