2. From predisposition to prevention
Mutations of certain genes predispose people to developing certain types of cancer. This is what happens, for example, with certain alterations in the BRCA1 and BRCA2 genes, which increase the chances of developing breast or ovarian cancer and tend to accumulate in some families (which is why Angeline Jolie chose to have these organs removed). The scenario, however, is complex: depending on which mutation a woman has, the risk is higher or lower, there can be interactions with other variants, or lifestyle or hormonal factors, and there are many mutations in other genes that are also being studied to determine their role.
Understanding the markers and risks in depth would help choose the best measures: surgery in some cases or, in many others, personalized periodic monitoring like mammograms for breast cancer. For this type, “in theory, combining everything, we could go from 5% prediction to 45%, but we don’t have those models yet,” explained Antonis Antoniou, a professor at the University of Cambridge who has participated in several international consortia on susceptibility to cancer.
According to Nicoline Hoogerbrugge, professor of Hereditary Cancer at Radboud University Medical Center, in the Netherlands, up to 40% of these patients have a family history of cancer but, in most cases, we do not know which genes are responsible. One that could be behind some cases is NTHL1, a gene that when mutated comes with a higher risk of colon cancer. Her group has also shown it increases the risk of breast cancer as well.
Some of these genes can also be found in a panel Hospital Vall d’Hebron has studied in more than 1,200 patients in recent years. The study, which will be published soon, was presented by Judith Balmaña, of the Vall d’Hebron Institute of Oncology. According to the results, adding a panel of 19 genes on top of those already commonly studied could help improve risk detection.
Preventative treatment would also be related. Really, the end goal, according to Jack Cuzick, director of the Wolfson Institute of Preventive Medicine in London, is to do what cardiologists did years ago: “starting to use risk factors (cholesterol, high blood pressure) as a treatable disease.” Something like this has been achieved with estrogen inhibitors, which are sometimes used to treat or prevent breast cancer. But work is underway to improve them and to find preventative therapies for tumors that these drugs don’t work on.
Cervical cancer deserves a chapter of its own. Mainly caused by infection with one of the different types of human papilloma virus (although infection does not necessarily mean it will develop), there is now a vaccine that is “extraordinarily effective for prevention,” said Francesc Xavier Bosch, senior researcher at IDIBELL Barcelona. Plus, there is a very powerful screening tool for the virus, “which is here to stay and will soon be widespread,” added Bosch.
Regular pap smears are currently used, although they are not that sensitive and cannot always identify lesions, which means they must be repeated often. Bosch is one of the promotors of the HPV-Faster program, which aims to extend the use of the vaccine beyond pre-adolescent girls: the idea is to give it to women under 30, or even 50 in some cases, along with a personalized screening program to consider giving it to men as well.