Hi and welcome to HCm.
Cancer is the last you should think of. This looks like blood clot, and causes of abnormal bleeding in women are various. Most of them arent serious. She should do hormone blood levels and pelvic ultrasounds to rule out ovary disorder
such as cysts or endometriosis
. You didnt mention her age. Different causes are common in different age groups. In peri and postmenopause uterus
cancer is more common and bleedings are usually irregular. In middle aged woman pregnancy
should always be excluded. The last possibility is pelvic infection
which can cause bleeding, disharge and ain in lower abdomen. I suggest to do tests i ve mentioned and then plan further treatment. Wish you good health and good luck Sir.