Megestrol acetate may combat weight loss during radiation treatments

Nov 28 2005

A new study by researchers at Wake Forest University Baptist Medical Center and colleagues shows that a drug originally used to treat breast cancer may help combat the severe weight loss that can plague patients undergoing radiation treatment for lung and head and neck cancer.

"The drug clearly reduced weight loss and improved quality of life in study patients," said Michael Farmer, M.D., who presented the results last month at the American Society for Therapeutic Radiology and Oncology (ASTRO) meeting in Denver.

The research involved megestrol acetate, a synthetic form of the female hormone progesterone. The drug was originally used as an anti-hormonal treatment for breast cancer and was found to induce weight gain as a side effect. Later studies showed the drug's effectiveness as an appetite stimulant for patients with HIV, chronic diseases and cancer cachexia, a "wasting syndrome" in which fat and muscle are lost because of the presence of a cancerous tumor.

Weight loss can also be a problem in patients undergoing radiation treatment for lung cancer and cancers of the head and neck, such as cancer in the mouth or throat. The high doses of radiation used to treat these cancers can cause decreased appetite and weight loss, nausea and painful swallowing. These patients typically receive radiation alone or a combination of radiation and chemotherapy, which can worsen the side effects of treatment, particularly nausea.

"Due to the pain and nausea, it is very difficult for patients to eat sufficient quantities of food and drink proper amounts of fluid during treatment," said Farmer. "It is a critical time to maintain adequate food intake and hydration, yet one of the most frequent complaints from patients during this type of therapy is a decreased appetite."

Farmer said the expected mean weight loss among these patients is about 12 pounds after eight weeks of radiation therapy and that weight loss is a significant predictor of how well patients fare.

"Weight loss is correlated with decreased overall survival, decreased quality of life and decreased response to treatment," he said. "In addition, if the weight loss is severe enough, it can lead to breaks in treatment that may decrease the effectiveness of therapy."

The study involved 38 patients with lung cancer or cancer of the head and neck who were treated at Wake Forest Baptist or through four other centers. Twenty patients received megestrol acetate daily during eight weeks of radiation treatment and for 12 weeks afterwards. The remaining 18 patients received an inactive placebo during the same time period.

The mean weight for patients receiving megestrol acetate did not change significantly. However, the group receiving placebo had a mean weight loss of 11 pounds after 20 weeks.

Previous studies with megestrol acetate in cancer patients focused on patients with advanced cancer who were already receiving radiation or chemotherapy and had already begun to lose weight. In the current study, patients were given megestrol acetate from the start of treatment, to prevent weight loss.

"While we know that weight loss is associated with a poorer outcome, we don't know for certain that preventing weight loss will improve survival," said Farmer. "This issue has not been well studied and warrants more attention," Farmer said.

The safety of megestrol acetate has been well-documented in the previous studies. Farmer said, however, that patients should be screened for a risk of developing blood clots.

"While there is a small increased risk of blood clots in advanced cancer patients who take megestrol acetate, we did not observe this in our study patients," he said.

The research was initially funded by Bristol-Myers Squibb Oncology. It was conducted by the Comprehensive Cancer Center of Wake Forest University Research Base, a National Cancer Institute funded network of 93 community cancer centers in 19 states working with Wake Forest to conduct clinical trials in cancer patients. Wake Forest is one of only six NCI-designated Cancer Center Research Bases in the nation performing community-based cancer clinical trials.

Farmer's co-researchers were Doug Case, Ph.D., Glenn Lesser, M.D., Michelle Naughton, Ph.D., Richard McQuellon, Ph.D., William Blackstock, M.D., Kathryn Greven, M.D., and Edward Shaw, M.D., all with Wake Forest Baptist, Drew Monitto, M.D., from the Gibbs Regional Cancer Center in Spartanburg, S.C. , Sesalie Smathers, M.D., from Mountain Radiation Oncology in Asheville, Byron May, M.D., from Wellmont Holston Valley Hospital in Kingsport, Tenn., and Ron Allison, M.D., from Brody School of Medicine, East Carolina University, in Greenville.