Those Suffering from Certain Types of Leiomyosarcoma Have New Hope

Written by Jeff Meyer on 25 May 2015

According to a new study that was recently published in The Lancet Oncology, those suffering from soft-tissue leiomyosarcoma and uterine leiomyosarcoma may have new hope. If these results can be replicated, then doxorubicin combined with trabectedin may work as a first-line treatment for these types of tumors. Researchers have already announced plans on carrying forward with another study for this very reason.

What Is Leiomyosarcoma?

Leiomyosarcoma is a type of malignant smooth muscle tumor. It’s also referred to as LMS. As a fairly rare form of cancer (though there are many different kinds), leiomyosarcoma only accounts for no more than10% of soft tissue sarcomas. Of course, that’s a fairly rare affliction all by itself.

One of the things that makes leiomyosarcoma so difficult to treat is the fact that it’s often very unpredictable. It can go dormant for extended periods of time and then come back after years. It also tends to be unresponsive to typical cancer treatments like radiation or chemotherapy, which is why this new development is so important.

For the most part, the best chance someone has is if the growth can be addressed early on and surgically removed with wide margins while it remains small.

Soft Tissue Leiomyosarcoma

One type of leiomyosarcoma is soft tissue. This cancer starts in soft tissues, which is where it gets its name, but can spread out of it too.

As your entire body is lined with soft tissue—muscle, tendons, fat, blood vessels, joints, etc.—this type of cancer can form just about anywhere. However, it’s most common in the abdomen and limbs.

There really aren’t any well-known risk factors that result in soft tissue leiomyosarcoma. This, combined with its rarity, makes it very hard to catch this type of cancer early or otherwise prevent it. The only familial syndromes that may mean someone is at risk are:

• Li-fraumeni Syndrome
• Neurofibromatosis
• Retinoblastoma
• Gardner’s Syndrome

Otherwise, there are no screening procedures currently in place, nor are there early warning signs to catch.

Uterine Leiomyosarcoma

This form of cancer is very similar to soft tissue leiomyosarcoma. However, it’s distinct for the fact that it attacks a woman’s uterus. Any type of malignant growth in this area’s cells is technically uterine leiomyosarcoma.

As with the type we just covered, no one knows for sure what causes this type of cancer. However, risk factors are believed to include obesity, endometrial overgrowth, having experienced menses before age 12, never having had children, menopause after 55, taking tamoxifen, estrogen therapy, a family history of it, radiation of the pelvis, and Lynch Syndrome.

A New Hope

In the study mentioned above, researchers were curious about what first-line doxorubicin combined with trabectedin would do when targeted at metastic leiomyosarcoma in soft-tissue or the uterus.

This single-group, multicenter, phase 2 study included 109 patients. They were given 60mg/m2 of doxorubicin and 1.1mg/m² of trabectedin intravenously on the first day. The following day, they were given 6mg of pegfilgrastim subcutaneously. This went on for three weeks for as many as six cycles.

By the end, 74% of those with soft-tissue and 68% of those with uterine leiomyosarcoma took six cycles. Overall, 87.2% of patients reached disease control as a result. 3.3% of the patients with soft-tissue leiomyosarcoma actually reached a complete response, whereas 36.1% reached partial.

It should be noted that there were some side effects to the protocol. Amongst them were neutropenia, anemia and fatigue.

The authors of the study concluded that a phase three version will be necessary in order to further develop this last drug combination. No word yet on what that may entail.

Sources:

http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(15)70070-7/abstract

http://www.cancertherapyadvisor.com/doxorubicin-trabectedin-sarcoma-cancer-treatment/article/404820/

http://www.lmsdr.org/whatis_leiomyosarcoma.php

http://www.mayoclinic.org/diseases-conditions/soft-tissue-sarcoma/basics/definition/con-20033386

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