Neuroblastoma

By Meg Marinis, Director of Medical Research Jan 19, 2012
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Wes still has his tumor. 

Were you surprised that Derek decided to close? It's not often that Derek Shepherd can't take out a tumor, but let's remember that EIGHT other neurosurgeons had all agreed that Wes' neuroblastoma was "inoperable."

Why was it so inoperable?

Wes' tumor is wrapped around several of the vital (and large) vessels that supply blood flow to the spinal cord. If Derek attempts to dissect the tumor out of Wes' body, he will inevitably cut one of those blood vessels… thus, paralyzing Wes and possibly even killing him in the process. At one point, one has to ask, is it worth it?

As Derek tells Lexie at the end of the episode, "They're not called lost causes because they're fun."

Wes suffers from neuroblastoma, which is a cancer that develops from nerve cells found in several areas of the body.

Known as a childhood cancer, neuroblastoma rarely affects anyone over the age of five (At age eleven, Wes is considered an unusual patient). This type of cancer is most commonly found in and around the adrenal glands – which sit on top of the kidneys – because they have similar origins to nerve cells. However, neuroblastoma may also develop in other areas of the abdomen, chest, neck, and pelvis. In rare and severe cases, the cancer has already spread so extensively by the time of diagnosis that doctors face difficulty in determining where it even began.

According to the American Cancer Society, neuroblastoma is the most common cancer in infants (less than one year old). Check out these other important statistics.

- Neuroblastoma accounts for about 7% of all cancers in children.
- In the U.S., approximately 650 new cases are diagnosed each year.
- The average age of diagnosis is about one to two years old.
- Nearly 90% of all cases are diagnosed by age five.
-In two out of three cases, the disease has already spread to other parts of the body when diagnosed.

The causes of neuroblastoma aren't completely known.

Risk factors for many childhood cancers are harder to determine than adult cancers. When studying adult diseases, one can factor in lifestyle choices such as smoking, diet, exercise, and body weight. These elements take years to develop into symptoms and hardly can contribute to childhood cancer.

In one to two percent of neuroblastoma cases, the children may have inherited an increased risk of developing the disease, but the majority of these cancers do not seem to be genetic at all. These familial forms of neuroblastoma often appear in families with one or more affected relatives who suffered from the disease as infants.

The signs and symptoms of neuroblastoma can greatly vary -- depending on the size and location of the original tumor, if the cancer has spread, and whether or not the tumor cells secrete hormones.

The primary tumor can appear as an unusual lump or mass, usually discovered in the abdomen. In these more widely seen cases, the children may experience swelling in the abdomen, lose their appetite, or complain of uncomfortable fullness. It can also press against or invade the blood and lymph vessels, preventing fluid from circulating back to the heart. The growing tumor's pressure can also affect the bladder or bowel, causing incontinence.

If the tumor initially develops in the chest, it may press on the superior vena cava, causing symptoms such as swelling in the upper chest, neck, face, or arms. Also, the tumor can impinge on nerves in the chest or neck, interfering with feeling or moving the limbs.

Neuroblastoma frequently spreads to the bones. Metastasis in the backbone can press on the spinal cord, causing weakness, numbness, or paralysis in the limbs. Blue or purple bumps may indicate that the disease has spread to the skin. If it infects the bone marrow, neuroblastoma can interfere with the amounts of red blood cells, white blood cells, or blood platelets. These shortages typically result in tiredness, irritability, weakness, infection, and excess bleeding.

Neuroblastoma cells may release hormones that affect other tissues and organs. Symptoms of these "paraneoplastic syndromes" include: constant diarrhea, fever, high blood pressure, rapid heartbeat, sweating, reddening of the skin, and muscle spasms. These secreted hormones are called catecholamines, which can be detected in the urine and blood.

Diagnostic methods for neuroblastoma:

- Complete blood counts.
- Liver and kidney function tests.
- Electrolyte levels.
- Imaging tests such as X-rays, CT Scan, Ultrasound, PET Scan, Bone Scans.
- Biopsies.
- Catecholamines for the paraneoplastic syndromes.

Most cancer centers use the International Neuroblastoma Staging System.

If doctors classify the neuroblastoma as Stage I, the cancer still remains in its original location, only on one side of the body (left or right). All of the visible tumor may be completely removed by surgery, and the lymph nodes outside of the tumor are still free of cancer cells.

Stage IIA also describes a cancer that has not moved beyond its original location, still confined to one side of the body. However, surgery may not be able to remove the tumor in its entirety. Lymph nodes outside of the tumor still appear free of cancer cells.

However, in Stage IIB, the tumor may have spread, but within the same side of the body. Surgery may or may not be successful in resecting the whole tumor, but the lymph nodes on the opposite side of the body still remain cancer-free.

If the neuroblastoma is assigned Stage III, the cancer has not spread too far, but one of the following characteristics applies:

1. The cancer cannot be completely removed by surgery, and it has now crossed the midline (the spine) to the other side of the body. It may or may not have spread to other lymph nodes.

2. The cancer still remains in the part of the body where it began, but distant lymph nodes now have cancer cells.

3. The cancer is in the middle of the body, seems to be growing toward both sides, and usually cannot be removed completely by surgery.

Stage IV neuroblastoma is obviously much more dismal. The cancer has spread to multiple sites in the body – various lymph nodes, the liver, skin, bone, bone marrow, or other organs.

Stage IVS is a special and rare form of neuroblastoma, only affecting children younger than one year old. The cancer remains on one side of the body, but it has spread to other lymph nodes on that particular side. This stage also includes metastases to the liver, skin, and/or bone marrow (though only 10% of bone marrow cells may be cancerous).

Recurrent neuroblastoma, though not formally part of the staging system, describes cancer that has returned after treatment. The cancer may come back in its original location or in another part of the body.

Treatment for neuroblastoma will always remain complex and involve the consultation of many health care professionals. It also depends on the child's age and stage of disease.

Treatment most likely will entail:

- Surgery.
- Chemotherapy.
- Retinoid Therapy.
- Radiation Therapy.
- Immunotherapy.
- High-dose chemotherapy/radiation and stem cell transplant.

Unlike many adult patients, children tend to tolerate chemotherapy better (though exceptions always exist). However, chemotherapy does have long-term side effects, therefore these children will need to be followed up for the rest of their lives.

For more information, please visit:

http://www.nlm.nih.gov/medlineplus/neuroblastoma.html