There is but it is very small. Importantly, women need to know that the overall risk of developing ovarian cancer is very low. It's clear that there is a slight increase in ovarian cancer in patients with endometriosis, but it is still very very small. Having endometriosis increases this risk minimally.
Also, there are 22 studies that we looked at and the risk ratio is 1.93. But it is difficult to combine the results as the individual studies were often very differently designed. This is called study heterogeneity. It is a problem.
They have found evidence of publication bias because, obviously, we talk about these cases when you find ovarian cancer and endometriosis at the same time, but the vast majority of women don't have it.