Isabel Portillo
Screening Coordinator at Osakidetza -Basque Health Service, researcher in the Cancer Biomarkers group at the Biobizkaia Health Research Institute, and secretary of the Board of Directors of the Spanish Epidemiology Society
It is an exploratory study. The most important limitation is the comparability of registers and series. It is not a systematic review and the quality of these sources is not analysed. The incidence of these groups is very low and the causes of their increase are certainly not well known; 5% may be related to genetic factors.
At the methodological level I consider that it should be more rigorous given the data sources. In Globocan, CRC incidence and mortality, as the article says, tends to decrease in the population screened 50-74 (which is uneven in different countries).
Further research is needed, especially on risk factors that are increasing (tobacco, obesity, alcohol, consumption of red meat and processed products...), which mainly affect people with a high level of deprivation.
[In terms of limitations] These have been taken into account. Above all because the quality of the registers is the greatest impediment to making comparisons.