Functional Tumors--The Challenge of Hormonal Imbalances

A certain proportion of NET patients will have to adjust to living with symptoms that the cancer is actively causing. NETs can upset your normal hormone balance; your doctor can help discern if your symptoms result from your tumors and, if so, how best to address them. It can take a long time to sort this out, which can be frustrating, but keep at it.

NETs that actively produce and release excess hormones into the body are called functional tumors. It is generally understood that about 20 to 35% of all patients may have some level of functional disease. This causes imbalances that affect your body and how it functions and may create dangerous, health threatening issues.

Non-functional tumors do not cause imbalances, either because they do not release hormones or they release such small amounts. However, it has been observed that some tumors that are originally non-functional can change after a while and begin to produce and release hormones.

Excess hormones can cause a myriad of symptoms referred to as a syndrome. Symptoms will differ depending upon where the tumor arises and which hormone is overproduced. The most common is carcinoid syndrome caused by excess serotonin. Patients will differ in the frequency and intensity of symptoms they experience. Some may require constant management of their symptoms while others may experience symptoms only occasionally. If you have any of the syndromes that can be caused by a functional NET, you may need the attention and care of a knowledgeable endocrinologist (a specialist in the endocrine, or hormone-releasing system) to help your oncologist sort out, treat and monitor your symptoms.

A typical treatment for the syndromes caused by functional NETS is prescribing somatostatin analogues (SSAs). Your doctor can discuss all the available variations of these medications with you. A medication called telotristat ethyl can be given along with SSAs to help control carcinoid syndrome diarrhea that is not managed by SSAs alone. In some cases, surgery to remove as much of the tumor load as possible is recommended. This is referred to as de-bulking surgery, and this can help reduce the effects of functional tumors.