Why isn't there a cure for breast cancer?

Posted on Jul 3, 2008 in Cancer

While it is well known that obesity, lack of exercise and alcohol all contribute to an increased risk of breast cancer, people often don’t take these preventive measures seriously, said Dr. Graham Colditz of Washington University in St. Louis.

From MSNBC.com

By Robert Bazell
Chief science and health correspondent

Billions of dollars have been dedicated to breast cancer research in the last decade. Why isn’t there a cure yet?

That was a question that rang out repeatedly in various forms at a panel I recently co-chaired with Fran Visco, president of National Breast Cancer Coalition. The panel was part of the fifth Era of Hope conference, which brought together many of the most committed breast cancer activists with some of the nation‚Äôs top cancer scientists. The conference’s directive is to push researchers to think ‚Äúout of the box‚Äù for potential treatments, methods of detection and prevention in new ways.

Every year the same question is raised: How can the search for breast cancer treatments be improved?

In the early 1990s the National Breast Cancer Coalition lobbied for the federal government to dedicate extra money for breast cancer research. Officials at the National Institutes of Health said they had no interest in spending huge amounts on one specific disease. As a result, the Coalition got the U.S. Congress to appropriate funds through the Department of Defense. Since then the Army has shown its skills at managing the DOD Breast Cancer Research Program. The program, which has spent some $2 billion already, has racked up some impressive accomplishments in high-risk research projects, including new vaccines that could play a big role in treatment and studies of the role of stem cells in breast cancer development.

During the panel, Christine Brunswick, a prominent lawyer and member of the NBCC board, described how she underwent painful and difficult treatments including a mastectomy and chemotherapy 18 years ago. She became “cancer free,” but a few months ago the cancer suddenly returned. How could this happen, she wondered?

‘No cause to apologize’
Confronting an individual’s difficult story is never easy, but Dr. Robert Weinberg, professor of cancer research at Massachusetts Institute of Technology explained that, while progress against breast cancer is not where it should be, there have been significant gains. While the overall decline in cancer death rate has been minimal, the age-adjusted death rate — the only true measure of progress — for breast cancer has plummeted more than 25 percent since 1990. “We could do better, but we have no cause to apologize,” Weinberg said.

Dr. Dennis Slamon, executive vice chair for research for UCLA’s Department of Medicine pointed out that doctors ‚Äúhad wasted 40 years treating breast cancer with a one-size-fits-all approach.‚Äù Slamon ‚Äî who co-discovered Herceptin, one of the most successful breast cancer drugs of the past decade ‚Äî said many new studies show that breast cancer is in fact a ‚Äúcollection of diseases that occur in the breast,‚Äù and much that more tailored therapy will appear within a very few years.

New understandings of genetics will soon transform treatment very soon, Dr. Funmi Olopade, a professor of medicine at the University of Chicago explained. Genetic analysis of both the patient and the tumor will allow doctors to give chemotherapy that works and avoid regimes that cause intensive side effects with little or no benefit.

Known risks
While it is well known that obesity, lack of exercise and alcohol all contribute to an increased risk of breast, people often don’t take these preventive measures seriously, said Dr. Graham Colditz of Washington University in St. Louis. In addition, Tamoxifen and other estrogen-blocking drugs, although they often come with side effects such as blood clots, reduce the risk of breast cancer.

“There are complex reasons why people chose to act or not on this known information,” said Coditz, who spent decades studying the risk factors for breast cancer in the Nurse’s Health Study and similar projects at the Harvard School of Public Health. “But the information is out there.”

Despite a better understanding of some of the causes of breast cancer, there are still a number of key unanswered questions. Weinberg offered a fascinating summary:
# What is it about the normal breast that determines which cells are vulnerable to cancer?
# Which cells in the normal breast are likely to spread to other tissues (metastasize) if they become cancerous?
# Is the ability to metastasize determined early or late in the multi-step process that coverts a normal cell to cancer?
# How do metastatic cells acquire the ability to live in other tissues, essentially a foreign environment?
# Why are breast cancer cells much more sensitive than other tissues to DNA changes that can bring on cancer?
# Why are women with dense breast tissue more susceptible to cancer?

“A few years ago I wouldn’t have even known to ask them,” he explained. The questions build on other findings, illustrating how science — pushed by activists — progresses.