I live near Seattle WA. and don't know anything about health care in Houston. I just did a search for Oncologists in Houston and came up with 3 searches. All of the doctor's listed have phone numbers and addresses for their offices and that is how you would make an appointment. Some will have a link that says... "Make An Appointment"
The first "healthgrades" is kind of a popularity contest. It asks patients to rate their doctors. As for the best, this isn't the way you pick THE BEST. It could be based on how they interacted with the patient, how friendly they were, their staff's. This has nothing to do with with his actual skill as an oncologist.
Again, this is another list of oncologist from WebMD
This is a great place...
These lists may help get you going. My regular doctor is an internist. He referred me to an oncologist who he has worked with for several years. He is the oncologist he would send his family or himself to. I am so grateful to have both doctor's treating me.
Remember, some oncologists specialize in certain cancers. Another thing to consider is some breast cancers, depending on type, size, stage, and mets, etc. are common and treatments are well established . If the cancer is late stage, you might consider a facility where you could become involved with drug trials, a teaching facility or true cancer insititute. I would start with your own doctor first, and see what he or she can find out for you. They probably have a better grasp of qualifications and better connections. It is a tough search if you are out there on your own trying to do your own search. My oncologist is connected with several facilities in Seattle. If he had questions, he has a lot of other professionals he could contact. Good luck on your search. Sharon