Fibroids and Cancer Risk

Fibroids are benign tumours that originate from the muscle layer of the uterus. They are the most common uterine tumour among women. As we mentioned in our previous articles, certain changes occur in these fibroids over time, and this is called ‘degeneration’. Although there are many types of degeneration, the most important of them is sarcomatous degeneration.

Sarcomatous degeneration indicates that the fibroid has now become a malignant tumour. Normally, because fibroids are benign tumours, they are not regarded as cancer. However, when sarcomatous changes are seen, the fibroid is then called cancer.

So how often are these sarcomatous changes seen?

Although the many studies carried out on this subject give different rates, the rate of sarcoma occurring in a fibroid (the probability of it being cancer) is stated to be on average 1 in 500 women. This probability increases as the age of the patient increases. In other words, in young patients the probability that a fibroid is malignant is lower.

It is very difficult to tell whether a fibroid is benign or malignant without operating. Although some methods are used today, this diagnosis is generally made after the fibroid has been removed and examined pathologically. If the pathological examination returns a diagnosis of sarcoma, the patient should be operated on again and the uterus, the ovaries and the lymph nodes in the groin region should also be removed. Chemotherapy is required after the operation.

If the fibroid is malignant and the operation has been performed laparoscopically or with the robot, because the fibroid is taken out of the abdomen with a morcellator (breaking the fibroid into pieces with an electrical device and removing it from the abdomen), it may also spread to the other organs inside the abdomen. To prevent this, today this procedure is performed inside durable bags. Because the fibroid is broken up inside the bag, spread to other organs in the event of possible cancer is prevented.