Can an ovarian cyst be causing swollen lymph nodes in groin (noticeable, not painful for months) and lower back pain?

Lymph nodes: Lymph nodes associated with ovarian cyst is concerning. Cancer needs to be ruled. Please see an OBGyn

Not typically : A "typical" ovarian cyst should not be associated with lymphadenopathy, although can be associated with back pain. A goid checkup with your medical doctor or gynecologist would probably be a good place to start.

It would: be very unusual for an ovarian cancer to present with inguinal adenopathy. Ovarian malignancy tends to stay intra-abdominal. So it is unlikely that your adenopathy is related to an ovarian cyst or mass, but you still need to get evaluated for the adenopathy.