There are some genes that cause more than one type of cancer, but you would have to get the medical reports from the relatives to see the specific types of cancer, and see a geneticist or genetic counsellor for further info.

In Victoria, all reports are collected through the Cancer Council of Victoria so it is an easier process to get access to the reports. In NSW, I believe that you have to get access to each person's medical information individually from their doctor, which requires permission from the person or next of kin. (The Genetic Clinic can help with this if it sounds like the cancers may be genetic)

In relation to the breast cancer genes, the criteria for 'potentially high risk' and follow up with a genetics clinic for those women without breast or ovarian cancer are:

Two primary or secondary relatives on one side of the family with breast or ovarian cancers PLUS one or more of these features in same side of family
*another relative with breast or ovarian cancer
*breast cancer diagnosed before age 40
*bilateral breast cancer
*breast and ovarian cancer in the same woman
*Ashkenazi Jewish ancestry
*breast cancer in a male relative

OR

One primary or secondary relative diagnosed with breast cancer at age 45 or younger PLUS another primary or secondary relative on the same side of the family with sarcoma (bone/soft tissue) at age 45 or younger.
Genetic testing through a familial cancer centre does not cost the 'patient' anything. Only those families that meet the criteria, and where the chance of finding a gene mutation is high will have genetic testing.

Other genetic testing can have out of pocket expenses, but you should be informed of this prior to the testing being performed.