Is there a link between breast cancer and ovarian cancer?

The doctors think my grandmother may have very advanced ovarian cancer, tests are coming back today. So is ovarian cancer hereditary? And I googled it, and all these things about increased risk of both ovarian and breast cancer are coming up. So is my risk for both cancer increased now? Are they linked in some way?

Cancer is rarely hereditary, and ovarian cancer is no exception.

Only about 10% of ovarian cancer cases are hereditary and caused by an inherited faulty gene. You don't say how old your grandmother is; most cases of ovarian cancer occur in women who have had the menopause, and ovarian (and other) cancers diagnosed after the age of 50 are even less likely to be hereditary.

The rare faulty inherited genes that increase the risk of ovarian cancer include BRCA1 and BRCA2; these genes also increase the risk of breast cancer

The chances are that you're not at increased risk of either cancer.

My best wishes to your grandmother

Yes these two cancers are linked so your grandmother, if she has ovarian cancer, has an increased risk for breast cancer. You however would not have an increased risk for either one unless you had two or more first and second degree relatives with either of these cancers. If you had a rare hereditary type in your family your grandmother would be under 50 years old and your mother or father would have to carry the gene to give you a 50% chance of inheriting it.