A newly developed compound may allow physicians to completely reverse the spread of breast cancer, illuminating a potential pharmacological strategy against some of the toughest cases of the disease that kills scores of American women every day.

Although many breast cancers come with somber prognoses, so-called metastatic tumors are especially nefarious, as they rapidly spread from the site of origin to surrounding tissue and organs. This makes it exceedingly difficult to deliver cancer-killing drugs without harming healthy tissue. Dr. Richard Clarkson, a researcher at Cardiff University’s European Cancer Stem Cell Research Institute and lead author of the new study, said in a press release that a recently discovered function of the gene Bcl3 may allow physicians to solve this problem altogether by blocking the tumor’s foray into neighboring tissue. "We showed that suppressing this gene reduced the spread of cancer by more than 80%," he said. "Our next goal was to then find a way to suppress Bcl3 pharmacologically.”

Using a computer model, Clarkson and colleagues were able to check potential pharmacological candidates against the characteristic of the gene. They eventually found a chemical capable of suppressing the tumor-driving function of the gene by fitting into a “pocket” on its surface. In experiments with mouse models of metastatic breast cancer, this compound was shown to completely inhibit the development of these tumors.

Reversing Breast Cancer

Today, breast cancer is the second most deadly cancer among U.S. women, affecting over 200,000 and killing nearly 40,000 each year. It is estimated that one in every eight women will develop the disease at some point in their life. While the cause remains unknown, risk factors include early puberty, late menopause, and certain genes. Lifestyle factors like calorie intake and alcohol consumption have also been implicated in higher risk for diagnosis.

The current study is the latest in a growing series of attempts to unravel the mechanics of metastasis — the tremendously complex process whereby cancer invades surrounding tissue and organs. Another example is a 2013 study from Rice University, in which researchers map the genetic “rules” that appear to underpin the process. Scientists hope that these efforts will eventually allow oncologists to prevent, disrupt, and even reverse metastasis.

“Despite great improvements in therapy of early stage breast cancer, the current therapeutic options for patients with late stage metastatic disease are limited,” Clarkson concluded. "There is therefore a clear unmet clinical need to identify new drugs to reverse or at least to slow down disease progression"