Most cancers are caused by genetic changes or mutations in cells. Sometimes the mutation is a minor change in a nonfunctioning area and does not significantly change the protein or new cells, but other times the mutation causes a normal cell to become a cancer cell. Research has identified some of the environmental factors that will cause a normal cell to mutate into a cancer cell, such as tobacco use, alcohol abuse or sun exposure. Less commonly, the damage to DNA is not from environmental sources, but rather it is inherited from a parent at the time of conception. Research has been able to identify inheritable DNA mutations that put families at increased risk for developing cancer.


Kathy Sieu, RN, MS, ANP-c, AOCNP and our genetic staffing continue to stay at the forefront of genetic testing and counseling with completion of programs like the Oncology Nurses Society and City of Hope’s intensive course for Cancer Genetic Risk Assessment. Genetic doctors and nurses with specialty training in cancer genetic risk assessment at Contra Costa Oncology, can examine a person’s family history to identify persons who should be offered genetic testing. Genetic counseling is an essential part of genetic testing because it helps identify and remedy emotional, financial and health related issues caused by the discovery of a cancer causing, inheritable, genetic mutation.


Genetic Counseling Services at CCO allow us to give specific recommendations to patients before they have cancer, or find it at a curable stage. Knowing if a person has a genetic mutation that predisposes them to cancer development, allows our team to advise a person regarding advanced screening practices, preventive medicines or cancer preventing surgery. New screening strategies for selected individuals at risk include: advanced screening procedures using techniques such as breast MRIs and early colonoscopy, plus life-saving interventions such as mastectomy, hysterectomy with oophorectomy, colectomy or prostatectomy.