Question: Does ovarian cancer increase colon cancer risk?
Women sometimes wonder if a personal (or family) history of ovarian cancer means they have to be extra concerned about colon cancer, too. Whether a woman with a history of ovarian cancer is at increased risk for colon cancer depends on why she (or her family member) developed ovarian cancer in the first place.
Answer: No one knows what causes ovarian cancer for sure, but certain genetic mutations increase a woman's chances of developing ovarian cancer. For example, you've probably heard of the "breast cancer genes," BRCA 1 and BRCA 2. The average woman has less than a two percent chance of developing ovarian cancer; women with BRCA 1 or BRCA 2 mutations have a 40-50% of developing ovarian cancer by age 70. So genetic mutations play a big part here. Now, how is that relevant to ovarian cancer and colon cancer risk?
There's another mutation that causes a condition called hereditary non-polyposis colorectal cancer (HNPCC). People with HNPCC have about an 80% chance of developing colorectal cancer at some point in their lives. They also have about a 10% risk of developing ovarian cancer.
So, the answer to whether ovarian cancer increases colon cancer risk isn't particularly straightforward. Unless you've had genetic testing, you need to look at the big picture to get a better idea of what's going on. If your family history includes colon cancer, you're already at greater risk for colon cancer so that's a no-brainer. But if it includes breast cancer and/or ovarian cancer, it'd probably be a good idea to write down who's had what and have a long conversation with your doctor about what that history may mean for you.