Is it possible to detect cancer before it appears? The Pan-Cancer Analysis of Whole Genomes Project (PCAWG) could make this a reality.
In this unprecedented study, published in Nature , more than 1,200 researchers from 37 countries have participated, sequencing the genomes of more than 2,600 cancer samples from 38 types of tumors . The result of this is the creation of the most complete and important genomic map of cancer that exists to date and that allows us to understand the complexity of the disease and how it develops.
Cancer is the second most common cause of death worldwide, killing more than 8 million people each year. In addition, the incidence of this disease is expected to increase by more than 50% in the coming decades.
The disease occurs initially when carcinogens alter the genetic material of a cell (mutation). The mutated cell will need to divide into cancer cells for cancer to occur. The cancer cells will then multiply faster than normal, passing the mutation on to their offspring.
“ Thousands of different combinations of mutations cause cancer ; over 80 different underlying processes generate these mutations, such as aging, causes hereditary or lifestyle , “explains to SINC Peter Campbell, a researcher at the Wellcome Sanger Institute in the UK and author of one of the studies that are part of Pan-Cancer . “However, one of the most interesting themes that has emerged now is that we can begin to discern recurring patterns among all this enormous complexity.” In this sense, researchers have detected at least one causal mutation in 95% of patients. For many tumors they have detected between 5 and 10 causal mutations. Detecting these patterns would help fine-tune diagnosis and treatment.
The Pan-Cancer Project is so important because it has managed to study 99% of the genome of the disease that remained to be investigated. This includes key regions involved in turning genes on and off.
Another of Pan-Cancer’s key findings is to discover how the genome of the disease can differ from patient to patient , which may explain why people with the same type of cancer respond differently to treatment. This discovery opens the door to personalized medicine design.
The investigations carried out within the Pan-Cancer Project represent an advance in the early detection of the disease in the sense that it has been discovered that important mutations for the appearance of cancer can occur in the body and that these appear many years before diagnosis . “This reaffirms us in the idea that it will be important to improve the diagnostic methods to advance the moment of the detection of a tumor as much as possible”, tells us Jose MCTubío, director of the group ‘Genomes and Disease’ of the CiMUS of the University of Santiago de Compostela, who has participated in the project.
“The most important advance of the Pan-Cancer Project is not a specific finding, but the fact that this project will serve as a proof of concept for much larger ones . We have realized, for example, that the project has led much longer than expected, which will lead us to improve logistics and will also require the improvement of faster and more efficient computational methods to be able to perform the analysis of hundreds of thousands of genomes in a reasonable time “, Tubío points out.
And there is more good news … Pan-Cancer scientists have developed a method to find out where cancers come from, that is, to find the cell of origin in those patients in whom it has not been possible using standard diagnostic techniques. So you know what type of cancer they have.
Spain has also participated in this revolutionary project. One of our most outstanding contributions has been the analysis of 95 chronic lymphatic leukemia samples at the Center for Genomic Regulation (CRG) and the study of retrotransposons (part of our genetic material that until recently was considered junk DNA) in development of various types of cancers at the University of Santiago de Compostela.
