Leiomyosarcoma of the uterine corpus (ULMS) is a rare tumor that arises from the smooth muscle cells of the uterus..

Leiomyoma, unlike leiomyosarcoma, is a very common benign tumor that also originates from smooth muscle cells..

Leiomyosarcoma of the uterus develops somewhat differently than leiomyosarcomas of other organs..

Epidemiology.

Leiomyosarcoma of the uterus is a very rare disease.. In the United States, only 6 women in 1,000,000 are diagnosed with this type of cancer each year.. The average age of the patients is 51 years.

At first, the disease may not manifest itself in any way, so it is extremely important to undergo periodic examinations.. Leiomyosarcoma is often found during a hysterectomy (removal of the uterus) in women with fibroids..

Diagnosis of uterine leiomyosarcoma.

Sudden-changing, rapidly growing benign uterine tumors in menopausal women should always be a concern.. It is very difficult to accurately diagnose leiomyosarcoma before surgery or tissue biopsy..

Magnetic resonance imaging (MRI) provides some information, but it is not enough. Some researchers report that a combination of MRI and a special blood test for serum lactate dehydrogenase (LDH) helps to accurately diagnose uterine leiomyosarcoma.. MRI-guided biopsy is considered an accurate method.

Treatment prognosis.

Surgery to remove the uterus is the main treatment for patients who are newly diagnosed with uterine leiomyosarcoma.. Initially, in 70-75% of patients, the cancer does not spread beyond the body of the uterus (stages I and II).

The 5-year survival rate in this case is 50% (data from the Sarcoma Foundation of America), while for most other types of gynecological cancer it exceeds 90% if the tumor has not spread beyond one organ. If leiomyosarcoma has spread to the cervix and outside the organ, the prognosis is very poor.

The tumor can grow very large and often recurs.. The prognosis is influenced by various characteristics of the tumor, such as the size of the tumor, the characteristics of its DNA, the status of hormone receptors, the characteristics of cell division, etc.. However, SFA experts say none of these factors currently provide a reliable predictor of disease progression.. Since these factors are not yet well understood, they may not influence treatment decisions..

Surgical treatment, unfortunately, does not prevent hematogenous metastasis of the tumor.. Despite surgical removal of the tumor and the use of the best available methods of treatment, 70% of patients recur within 8-16 months after diagnosis.. With this course, the disease is much more difficult to control.. Leiomyosarcoma of the uterus has a tendency to metastasize to the liver and lungs.

Available options include surgery, chemotherapy and radiation therapy.

Treatment for leiomyosarcoma of the body of the uterus I and II stage.

Surgical removal of the tumor is the main method. Sarcoma Foundation of America experts say that in stage I and II ULMS, a total abdominal hysterectomy (complete removal of the uterus) should be performed as soon as possible. Removal of the ovaries and fallopian tubes (bilateral salpingo-oophorectomy, BSO) is recommended for patients who are menopausal or have metastatic cancer.

Microscopic ovarian metastases occur in 3% of women with uterine leiomyosarcoma, which is why some doctors advise even young patients to remove the ovaries. The situation is aggravated by the fact that the growth of leiomyosarcoma can be stimulated by hormones produced by the ovaries..

Theoretically, this is the correct approach.. However, American researchers have not yet received enough reports that the number of relapses in young women after BSO is less than in women who did not undergo this procedure.. This may be due to the fact that estrogen and progesterone receptors are not found in all cases of leiomyosarcoma..

To date, according to the SFA, there is no evidence of an overall benefit of chemotherapy or radiation therapy after surgical removal of uterine leiomyosarcoma.. Chemotherapy and radiotherapy given after surgery are called " Adjuvant pelvic irradiation may reduce the likelihood of cancer recurrence in this area, but it does not statistically affect the risk of tumor occurrence in other organs (lungs, liver), namely, 80% of tumors form in other organs if a recurrence does occur..

Adjuvant chemotherapy has also not shown any clear benefit to date.. The largest clinical trial of adjuvant chemotherapy in ULMS using the most active drug, doxorubicin, showed that the recurrence rate and survival are almost independent of the administration of this drug after surgery.

Today, American experts do not recommend the routine use of adjuvant chemotherapy, except for participation in clinical trials of promising new drugs.. A combination of two drugs, gemcitabine and docetaxel, has recently been shown to be highly effective and is currently being actively studied in the United States..

After the operation, constant monitoring is recommended.. American doctors advise to undergo examinations at least once every 3 months during the first 3 years, and also to do a CT scan every 6 months.

Treatment of stage III and IV leiomyosarcoma and recurrent leiomyosarcoma.

Treatment in such cases is purely individual.. Surgical removal of all tumors is the best option, but this is not always possible.. Radiation therapy can be used to shrink the tumor and increase the chance of a successful surgery.. Response to conservative therapy alone is usually mild.

The most effective drugs in the past, doxorubicin and isophosphamide (ifosfamide), in combination gave a good result in 30% of patients. A recent clinical trial showed a 55% response rate to the combination of gemcitabine and docetaxel. Other drugs such as vincristine, cyclophosphamide, dacarbazine, topotecan, paclitaxel, etoposide, and hydroxyurea do not give encouraging results..

According to SFA experts, even with the use of the most effective of these drugs, the period without disease progression (relapse) is less than 1 year.

Targeted Therapy.

New targeted drugs against uterine leiomyosarcoma are still under study. In America, patients with this type of cancer in the advanced stages are recommended to take part in clinical trials of new drugs..

Organizations in the United States that are involved in the study of uterine leiomyosarcoma:.

• Information Center for Genetic and Rare Diseases.

• Sarcoma Foundation of America (Damascus, Maryland).

• American Cancer Society (Atlanta, Georgia).

• BeatSarcoma Organization (San Francisco, CA).

• Lance Armstrong Foundation (Austin, Texas).

• Northwest Sarcoma Foundation (Portland, Oregon).

• Rare Cancer Alliance (Green Valley, Arizona).

• Sarcoma Research Alliance (Mill Valley, California).

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