If you have a strong family risk of contracting cancer you may be available to get a BRCA, or other genetic test done under the Spanish social security system.
Your oncologist will decide if you qualify for the test.
There is also the option to have this done privately.
Having a genetic test has its pros and cons, this website may help you make when it comes to making a decision whether to test or not.
If you decide to go ahead with the testing, but this will not be covered by the social security there are quite a lot of options, the following laboratories have been recommended to us by other members, but there are many more available.