It means you may have ovarian cancer, very common in breast cancer survivors. You should have been tested for BRCA1, BRCA2 PALB 1&2 and P53 genetic defects with your cancer and if you weren't, you need to be as soon as possible. If you have any other 1st (mother, sister) or 2nd degree (grandmother, 1st cousin) female relatives with breast, ovarian, colon or pancreatic cancer, your need to be tested becomes urgent.
SUV (standardized uptake value) is a semiquantitative measure of metabolic activity on PET (positron emission tomography), an imaging test used in nuclear medicine/radiology typically used to stage or restage cancers. SUV may be influenced by various factors, including but not limited to image noise, low image resolution, and variable user-biased region of interest (ROI) selection, as well as patient sugar/glucose levels. There are some structures in your body that normally exhibit high SUV, such as the urinary collecting system, heart, brain, just to name a few. For other regions that do not normally exhibit high SUV, a high SUV may indicate pathology, such as infection, inflammation, and/or cancer. The cutoff between a benign and malignant lesion is roughly SUV 2.5. In your case, hypermetabolism in your ovary is suspicious for cancer, either primary (i.e., ovarian cancer) or secondary (i.e., metastasis). You should follow up with your oncologist regarding further workup and management.