Chemotherapy clinical trials for leiomyosarcoma (LMS) were discussed briefly Oct. 8 at the National Leiomyosarcoma Foundation patient symposium in St. Louis, Mo. This was one of several cancer treatment topics that I am reporting about during the coming weeks.
There are 70 different types of sarcoma, and treatment is moving toward individual types of sarcoma using genetically specific molecular therapy, said Dr. Scott Okuno, Chief Medical Officer in Sarcoma Alliance for Research Through Collaboration, a non-profit research cooperative, and professor of oncology at Mayo Clinic.
“As we get deeper into LMS, we find molecular subtypes of LMS,” he said.
He explained that adjuvant treatment is preventative. Typically a tumor is removed and the patient is given additional treatment to eradicate microscopic metastatic cells.
Neoadjuvant treatment is given prior to removal/ablation of a tumor, and is used to shrink the tumor and eradicate any microscopic metastatic cells.
In determining which path to follow, the physician will look at outcomes. For neoadjuvant treatment, for example, perhaps 33 percent (about three of 10 patients) will have a recurrence.
With adjuvant treatment, there might be another 33 percent reduction in recurrence—which means instead of three out of 10 patients with recurrence, there will be two out of ten patients with recurrence.
Chemotherapy is given when a tumor cannot be surgically removed.
In clinical trials, a tumor has to decrease in size by 30 percent to be considered a partial response.
Progression has to be a greater than a 20 percent increase for the treatment to be considered no longer working.
Sometimes the lump might get bigger but the tumor is dying, so the percent increase in size is allowed. One needs a sarcoma specialist to determine if the growth is from dying cells or from a growing tumor.
Dr. Mohammed Milhelm, director of the Melanoma Program at the University of Iowa, added, “We really don’t know what’s going on inside the tumor.”
Dr. Okuno said Gemzar and Taxotere together aren’t showing much difference beyond just what Gemzar can do. Dacarbazine alone doesn’t make much difference. Yet when Gemzar and dacarbazine are combined, patients tend to have better outcomes. A difference in outcomes also was found in the rate of infusion—for example, infusing the same amount of chemotherapy over a longer period of time can result in better outcomes.
