I'd look more at the worry/argument aspect of this explanation. The miscarriage which could spark a "loss conflict" would have resulted in ovarian cancer, as the cell proliferation in your ovaries has the biological purpose of making you more attractive and fertile in order to conceive another child.

A 10-year period is hard to account for and recall. Did you get multiple opinions from different histologists at different times? I only ask because sometimes they declare "malignant" when in fact the tissue had stopped proliferating. If you had two opinions and both came back as malignant, then the worry/argument conflict you had running was still active at that time. In other words, it is something you had not yet resolved. And in fact, it may still be unresolved now as we speak, if you're still receiving conventional treatment.

Sometimes you have to really step back, relax and allow the answer for some of these things to arise in your awareness. Often times we bury certain situations from our day-to-day awareness. And these can also be tricky as women, especially mothers, are biologically-wired to worry, especially for their children. But the key here is an ongoing worry that you've had for a long period of time that was at least active up until the time of your diagnosis, and perhaps still ongoing.

If the worry/argument situation doesn't jump straight to mind now, drop it into your inner-self and simply ask for clarity (from God/Jesus/Holy-Spirit if you're a Christian - from the universe if not - or from whatever higher power you believe in) when the time is right for you. It may take days/weeks even months for something to bubble up. It's a very individual situation. Just look for a long-running, nagging worry you've had surrounding someone you love that is either still unresolved or was only recently resolved (after your diagnosis).