[Morphology as the starting point for individualized cancer treatment]

Historically, the histopathological diagnosis has been essential for the proper treatment of cancer. Today, in the new era of individualized cancer treatment, pathologists acquire a new role for identifying therapeutic targets, detection of hereditary syndromes; to select the most suitable molecular technique for each sample or to assess individual response to neoadjuvant therapy. The objective of this review is to show how we must combine and integrate new gross examination, microscopic and immunohistochemical data with molecular pathology, taking the example of colorectal cancer. Immunohistochemistry for DNA repair genes, the study of K-ras mutations and circumferential resection margin in rectal adenocarcinoma are part of this new reality. Therefore, besides making the correct diagnosis and staging of the tumor, we can play a key role in risk stratification of cancer and individualized treatment. Integration of the molecular study with the morphology and clinical data by pathologists may improve the efficiency of genetic tests and save costs. Phenotype precedes genotype in the clinical management algorithm of the disease.