Neuroendocrine tumor treatments

Using special needles to heat or freeze tumors can destroy them. We may recommend tumor ablation for small metastatic tumors, particularly in the lungs, liver and bones.

Radiation therapy delivered by a machine from outside the body can relieve symptoms and treat confined tumors. Many programs just use it for paragangliomas in the head and neck or for cancer that has spread to bones. At Penn, we may consider radiation more often, including for some lung NETs and after certain surgeries to target remaining cancer cells. We may also use it if a metastatic spot appears after other treatment. We offer the latest approaches, including proton therapy, with the expertise to get good results.

When NETs spread to the liver, treating them is a priority because of the organ’s critical role. Therapies destroy tumors or slow their growth, using needles or catheters (thin tubes). Our team recommends when to treat the liver, and which options to use.

When making treatment recommendations for a neuroendocrine tumor, we determine early on if we can completely and safely remove it. Surgeons call this removal of tissue resection, and it may sometimes require removing an organ or a gland.

Looking to surgical removal first provides the best possibility of a cure, assuming the tumor is localized (not yet spread beyond nearby lymph nodes). Remaining NET cells may cause disease to eventually return. This is a possibility we watch for. Surgery also relieves symptoms and stops hormone release, a feature of many NETs. It may provide all the treatment you need.

Even if tumors have turned cancerous and spread, removing all the disease may still be possible. For example, if a pancreatic NET has spread to a limited number of spots in the liver, we may still operate on both the pancreas and the liver. This approach differs from many other cancers — it’s not usually the approach when more common pancreatic cancers spread, for example.

Our approach to surgery also includes:

• Minimally invasive techniques: When possible, our surgeons take a minimally invasive approach, with smaller incisions. This method usually means a shorter hospital stay and faster recovery. For lung NETs, we remove as little tissue as safely possible, to protect lung function. For pheochromocytoma, some uncommon genetic changes can lead to tumors in both adrenal glands. We can perform surgery to spare gland tissue (cortical sparing adrenalectomy).
• Follow-up therapies: Removable NETs typically don’t require additional treatment right after surgery. However, we may follow up with chemotherapy, radiation therapy or both for tumors that are poorly differentiated. That distinction means their cells look very different than normal cells.
• Alternatives: Some paragangliomas sit too close to head and neck nerves for removal. We can use radiation therapy to treat such tumors while protecting those nerves. For other tumors, we occasionally combine treatments, such as surgery for the main tumor and ablation for metastatic spots. Ablation burns or freezes tumors.

Even when we can’t remove all the disease, surgery can still play an important role. With a single large tumor, we can reduce its size as much as we can. With multiple tumors, we take out as many as we can. This approach can reduce hormone release, provide better long-term disease control and lessen symptoms. It can also prevent complications and make other treatments more effective and easier to tolerate.

We commonly use debulking on the liver when tumors have metastasized there; we also occasionally use it in other locations. If we can remove most of the disease in the liver, we can set the clock back significantly in how cancer has progressed. We can also potentially put off therapies that could prove harder on the liver.

Even when metastatic disease is not removable, taking out the original tumor can still provide benefits, especially in the GI tract. If safely possible, we’re committed to finding and removing these primary tumors, a step not all programs take. If primary intestinal tumors are left in place, over time they can block the GI tract, continue releasing hormones, form additional metastases or (less often) cause bleeding.

We may wait to take out the primary tumor until we have met other, more pressing needs, such as treating the liver. While we mainly take out primary tumors in the intestines, we may occasionally recommend doing so in other areas, such as the pancreas.

We may sometimes recommend additional surgeries, even when there is no disease present:

• With some pheochromocytomas driven by inherited genetic mutations, we may also recommend taking out the thyroid gland because of the risk of other tumors.
• Somatostatin analogs, a common NET drug therapy, can cause gallstones to form. We may recommend taking out the gallbladder as a precaution if you’re undergoing other surgery.

As with other operations, you may experience some pain or nausea after a NET surgery.

Other possible side effects include:

• Diarrhea and vitamin deficiency if we remove a portion of the GI tract
• Too little digestive enzymes or insulin if we take out some of the pancreas

Our team can help relieve any side effects of surgery. For example, we can provide medications to control diarrhea and support pancreatic function.

We have a range of options for medications, with more in clinical trials. One class of drugs mimics a particular hormone, to relieve symptoms and control tumor growth. A newer approach, targeted therapy, aims at features tumor cells use to grow. And chemotherapy can shrink cancer that has spread further and aggressive NETs.

This newer form of treatment delivers internal, targeted radiation therapy to control tumors. It combines radioactive isotopes with molecules that many NETs take in. We led the national trials for the current options, peptide receptor radionuclide therapy (PRRT) and metaiodobenzylguanidine (MIBG) therapy.