A cancerous tumor in the pelvis ?

My aunt (41 years old) had a cancerous tumor in her pelvis next to her right bladder, and as a consequence she had right leg pain for 6 months but she had no idea it was because of a tumor and so did the doctors. After 6 months they discovered the tumor when she got an MRI and she got it removed, but the cancer didnt spread, nonetheless she removed her right ovary and uterus to avoid any future occurrence of the tumor. The doctor says she is clean now but she is undergoing 3 sessions of chemotherapy and maybe radiology afterwards to reduce the pain in her leg that the tumor has caused. Is anyone familiar with this type of cancer? and her mother had ovarian cancer when she was above 50 years old, so could it be hereditary ?