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Rhabdomysarcoma

Rhabdomyosarcoma is a rare and potentially deadly cancer that affects children. Striking various systems of the body, it can arise from the genitourinary tract. But what are its symptoms? How should it be treated? The following information should help you talk to an urologist about this condition.

What happens under normal conditions?

Under normal circumstances, children do not have large lumps in their abdomens or the area of the genitalia and rectum. They should also be able to urinate without straining and empty their bladders completely, with no sign of blood in the urine.

What is rhabdomyosarcoma?

Rhabdomyosarcoma is a rare cancer that affects only 4.5 out of one million children. Of these children, about 20 percent will have rhabdomyosarcoma in the genitourinary tract. There are two peaks at which rhabdomyosarcoma is found: from ages two to four and then from ages 15 to 19. Symptoms of rhabdomyosarcoma depend on its location. Rhabdomyosarcoma of the genitourinary tract affects the bladder, prostate, vagina and paratesticular areas.

What are the symptoms of rhabdomyosarcoma?

This cancer is usually not painful but can grow to a large size before it is detected. It can cause bleeding, trouble urinating and large lumps. Rhabdomyosarcoma of the bladder or prostate can cause trouble with urination or show as blood in the urine. Rhabdomyosarcoma in the vagina may show symptoms like a lump in the vagina or as foul smelling, bloody discharge. In the paratesticular area, rhabdomyosarcoma causes a swollen, painless scrotum.

How is rhabdomyosarcoma diagnosed?

If your child's physician suspects rhabdomyosarcoma, he or she will order an ultrasound initially to confirm the diagnosis. Additional studies can include a CT scan or MRI, chest X-ray, liver blood tests, bone scan, bone marrow tests and/or biopsy to determine whether or not the cancer has spread elsewhere in the body.

How is rhabdomyosarcoma treated?

The proper treatment of rhabdomyosarcoma consists of surgery, radiation (X-ray treatments) and chemotherapy (cancer-killing drugs given in the hospital intravenously. However, the proper order and extent to which each contributes to treatment and/or cure remain controversial. Since rhabdomyosarcoma is a rare cancer, patients in the United States are usually entered into the Children's Oncology Group (COG) studies by their treating oncologist. The COG conducts studies to optimize the treatment of rhabdomyosarcoma. The COG has taken over responsibility for conducting studies from the Intergroup Rhabdomyosarcoma Study (IRS).

Bladder and prostate tumors are initially treated with chemotherapy after the biopsy reveals rhabdomyosarcoma. There are many drugs effective for chemotherapy of this cancer; common ones are vincristine, dactinomycin, cyclophosphamide or a related three-drug combination. After chemotherapy, reevaluation is carried out to decide if the tumor can be completely removed while still maintaining urine and bowel control. If the cancer is found to be contained in the bladder or prostate, then the affected organ can be removed. However, usually, only a portion of the bladder is removed (partial cystectomy). If the bladder is completely removed, then during the same operation, a new reservoir is usually made out of intestine to allow for storage of urine. In the fourth IRS study, 37 percent of patients were treated with partial cystectomy and another 13 percent had complete removal of their prostate. If significant disease remains during the second-look operation, then another biopsy is taken and radiation is given. At some centers, chemotherapy is continued after the second-look operation and radiation is given only after all visible tumor is surgically removed. If a patient still has signs of rhabdomyosarcoma following chemotherapy and radiation, then the bladder, prostate or rectum is removed. This requires formation of a colostomy (bag for stool) and either a urostomy (bag for urine) or creation of a urinary reservoir.

In 80 percent of cases, vaginal rhabdomyosarcoma is successfully treated with limited surgery followed by chemotherapy. Following chemotherapy, a biopsy is usually obtained to confirm that the cancer has been adequately treated.

Paratesticular rhabdomyosarcoma occurs most often in three to four month old infants and in teenagers. Since it can be confused with testis tumors in the teenager, blood tests for testis cancer should be obtained. A CT scan is obtained to determine if the cancer has spread to the lymph nodes around the aorta and kidneys (retroperitoneal lymph nodes). The current COG study recommends that all boys under 10 who do not have suspicious lymph nodes on a CT scan be treated with less intense chemotherapy. Removal of retroperitoneal lymph nodes is recommended for boys under 10 with suspicious lymph nodes. It is recommended that boys over 10 should have the affected lymph nodes removed regardless of what the CT scan shows, since about 30 percent of these patients who did not have suspicious lymph nodes on CT scan eventually needed treatment for cancer in those lymph nodes. The intensity of the chemotherapy is then based on whether the pathologist finds cancer in the lymph nodes. If cancer is found, then cyclophosphamide is added to the treatment.

What can be expected after treatment for rhabdomyosarcoma?

Removing any part of the bladder can cause frequent urination because the organ's size is then decreased. The addition of radiation to the pelvis can damage the nerves that supply the bladder and prostate, leading to incontinence by damaging the urinary sphincter, which holds urine in the bladder. In the last IRS study, 40 percent of patients stated that they had normal urinary control.

Removal of the prostate can lead to incontinence and impotence. By using the techniques developed for prostate cancer, these risks can be decreased. However, since patients undergoing this surgery are teenagers, there must be long-term follow-up to determine how successful these procedures are. Likewise, data on sexual function of girls treated with partial removal of their vaginas are not yet available.

Treatment of the paratesticular rhabdomyosarcoma may require removal of the retroperitoneal lymph nodes, which can lead to loss of ejaculation and subsequent problems with infertility. Again, borrowing the techniques developed for adult testis cancer, this risk can be decreased. Whether or not a teenager should be banking sperm prior to surgery depends on the maturity level of the teenager and should be carefully discussed with the family.

In any case, patients will need frequent CT scans and biopsies to determine whether the cancer is responding since failure to respond to treatment, rather than recurrence, is the more concerning issue. Careful review of biopsies obtained during a second-look operation is necessary to determine if remaining masses are truly cancer. While there are no known preventive measures, some research indicates that genetic changes are responsible for high-risk cancer.

Frequently asked questions:

Are there any long-term risks with chemotherapy and radiation, particularly in treating paratesticular rhabdomyosarcoma?

Patients who undergo chemotherapy or radiation, particularly higher dosages, are also at a somewhat higher risk for other malignancies, such as lymphoma, leukemia and, on occasion, sarcoma. Statistics show that they occur in 1.7 percent to 6 percent of patients who survive 10 years after initial treatment. Since the testes are usually out of the area treated with radiation, they are usually not affected. However, chemotherapy can result in small testes and low sperm counts. The testosterone-producing cells are less affected so testosterone replacement is not usually needed.

What have previous studies taught physicians about the treatment of rhabdomyosarcoma?

Scientists have learned that radical surgical removal of internal organs and tissues is not necessary. These rates have improved up to 85 percent by combining surgery, chemotherapy and radiation. Thus, surgeons have moved toward a combination therapy to lessen the risks of urinary and stool incontinence as well as sexual dysfunction. The current COG study is concentrated on reducing the chemotherapy dosage for low-risk patients and increasing chemotherapy for high-risk patients while maintaining a high quality of life for all patients.

What are the current controversies in rhabdomyosarcoma?

Chemotherapy, radiation therapy and surgery have proven their worth in the treatment of rhabdomyosarcoma. But scientists and oncologists have yet to determine the exact role of each type of treatment. Researchers are currently addressing a variety of questions such as:

Is radiation in addition to complete surgical removal of an organ helpful in increasing survival? If so, how much?
Should chemotherapy or radiation be applied after a second-look surgery during which residual disease is found?
Should boys with paratesticular rhabdomyosarcoma over age 10 have their retroperitoneal lymph nodes surgically removed, followed by chemotherapy, or should they have chemotherapy first with possible surgical removal of the nodes?

Can paratesticular rhabdomyosarcoma appear later in life?

Paratesticular rhabdomyosarcoma can show up in adult men. Unfortunately, research has revealed that CT scanning is correct only 40 percent of the time in determining whether the retroperitoneal lymph nodes were involved. The largest experience from Indiana University suggests that all of these adult patients should undergo removal of the lymph nodes followed by chemotherapy.

If rhabdomyosarcoma affects the vagina, will treatment alter sexual function?

Since only part of the vagina is removed during surgery, the uterus and ovaries are left intact and so the possibility of normal sexual function still exists.