Cancer is a multifactorial disease that occurs due to the combined effect of genetic and environmental factors. It is estimated that between 5 and 10% of cancers are hereditary. However, it is not the cancer itself that can be inherited, but rather the genetic predisposition or susceptibility to suffer from a specific type of cancer.
When we speak of hereditary cancer, we are referring to mutations in specific genes that occur in germ cells, which are inherited from parents to children. Therefore, the disease is not being inherited, but these cells with the mutation in their genes.
Currently, there are many mutations identified in cancer. If a person has a genetic test, he can find out if he has any of the mutations studied. The fact of having a genetic mutation does not ensure that you will suffer from cancer, but that you have a greater probability of suffering from that particular type of cancer.
In the case of breast cancer, the genes studied are BRCA1 and BRCA2, among others. If you have affected relatives in different generations, it is important to carry out early detection tests to be able to act in time. To find out whether or not one has mutations in BRCA1 and/or BRCA2, a DNA test can be performed. If the mutations are present, it means that there is a greater susceptibility to breast cancer and, furthermore, that you can pass it on to your offspring.
However, the fact of not having the mutation does not indicate that you will not suffer from cancer, and the fact of having the mutation does not indicate that you will suffer from cancer; but it does indicate a greater predisposition and, therefore, it is important to have early controls in order to act in time.
On the other hand, colorectal cancer can be caused by a hereditary genetic condition called Lynch Syndrome or hereditary colorectal cancer not associated with polyposis (HNPCC). This syndrome is hereditary because it is caused by mutations or genetic changes that are passed from one generation to the next. These mutations occur in genes related to the development of colon cancer and can be studied with a genetic test. People with Lynch syndrome are much more likely to develop colorectal cancer.
It is estimated that Lynch syndrome causes between 2 and 7% of all colon and rectal cancers that are diagnosed. Colon cancer is the third most common form of cancer. Early diagnosis may be the key to its cure or treatment. However, once again, colon cancer is not inherited from parent to child, but rather a greater predisposition to colon cancer.
The role played by genetics in each particular cancer continues to be studied. In recent years, some mutations have been linked to certain genes that are involved in the development of lung cancer. Specifically, it is estimated that certain mutations in the EGFR gene and in the KRAS gene are responsible for half of all lung cancers. Several mutations have been identified in other genes that could also be involved in the development of this cancer. So these genetic relationships would explain why some non-smokers get lung cancer.
If a person has a greater genetic predisposition to develop this cancer, at the slightest suspicion he or she should see a specialist. In lung cancer, early diagnosis is the main condition for successful treatment. Although smoking remains the most important trigger for lung cancer, the role played by genetics should not be forgotten.
If there is a suspicion that the cancer detected may be hereditary, the quickest and most reliable thing to do is to perform a genetic test; however, there are some characteristics that can be related to hereditary cancer. For example: the presence of the same type of cancer in several members of a family, the appearance of cancer at an earlier age than usual, the appearance of several cancers in the same person, the appearance of a cancer typical of one sex (female and breast cancer) in a person of the opposite sex, etc. If you have these characteristics, the most advisable thing to do is to have a genetic analysis and see if you have mutations in the genes studied in order to be able to take preventive measures.
In short, hereditary cancer is an increasingly common occurrence in many families. In spite of this, more advanced and more precise technologies are becoming available that allow us to genetically analyze cancers. If we know our genetic predisposition, we can influence the interaction with the environment to prevent, as far as possible, the appearance of hereditary cancer.