New type of drug shrinks primary breast cancer tumors significantly in just 6 weeks

April 17, 2008

A drug that targets the cell surface receptors that play an important role in many types of cancer can bring about significant tumour regression in breast cancer after only six weeks of use, a scientist told the 6th European Breast Cancer Conference (EBCC-6) today. Dr. Angel Rodriguez, from the Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, USA, said that the work demonstrated for the first time that the tyrosine kinase inhibitor lapatinib could decrease tumour-causing breast cancer stem cells in the primary breast cancers of women receiving neoadjuvant treatment (treatment given before the primary surgery for the disease).

Dr. Rodriguez and colleagues studied 45 patients with locally advanced breast cancer in which the gene HER-2 was over-expressed. The patients received lapatinib for six weeks, followed by a combination of weekly trastuzumab and three-weekly docetaxel, given over 12 weeks, before primary surgery. Biopsies were performed at the time of diagnosis and also after six weeks of lapatinib and cells from the tumours were obtained and analyzed.

“We saw significant tumour regression after six weeks of single agent lapatinib,” said Dr. Rodriguez. “Bi-dimensional tumour measurements showed a median decrease of minus 60.8%. We had previously showed that tumour-causing breast cancer stem cells were resistant to conventional preoperative chemotherapy; indeed, residual cancers that were exposed to such chemotherapy showed an increase in tumour-causing cells and enhanced tumour initiation by the formation of mammospheres, small tumours that form when tumour-causing cells are cultured in a test tube, which reflect the capacity of the cells to self-renew. So we were excited to see that the results with lapatinib were different.”

Dr. Rodriguez’s results suggest that specific signalling inhibitors of the pathways responsible for stem cell self-renewal could provide a possible therapy for eliminating tumour-causing cells in order to achieve the long-term eradication of cancer.

Cancer stem cells help maintain the malignant tissue in the tumour by regenerating the tumour after attack from chemotherapy drugs. “This indicates that the stem cells themselves should be the specific target of chemotherapy drugs,” said Dr: Rodriguez. “Rather than the broad brush approach, in which cells are killed indiscriminately, targeting the stem cells may be more effective and also prevent some of the unpleasant side effects associated with conventional chemotherapy treatment.”

Scientists believe that cancer stem cells come into being through damage to their own DNA, which affects the regulation of their self-renewal. Other cells divide into two ‘daughter’ cells, but a stem cell can divide into a new stem cell and a ‘progenitor’ cell. The progenitor cell loses the power of self-renewal, but can still change into the cell type of the tissue served by the stem cell. The stem cell population then continues to renew itself as it generates new cells for the tissue. “This means that, unlike other cells, the stem cell has lost control over its own population size,” said Dr. Rodriguez.

Lapatinib has few side effects, and those that exist are minimal, including diarrhoea and acne. But it is expensive. “In the US it costs between $2000 and $3000 a month,” he said.


“This is an exciting finding, and we will be starting further studies on stem cells in order to confirm it. We will also look into its applicability in testing novel agents targeting tumour-initiating cells. This finding should also apply to other types of cancers and research of tumour-initiating stem cells in other cancers is ongoing,” said Dr. Rodriguez.

“International studies are currently underway looking at the effect of lapatinib in lung, colon, head and neck, gastric, oesophageal, and bladder cancer and lymphoma, among others,” he said.

Source: ECCO-the European CanCer Organisation

Explore further: New findings explain how UV rays trigger skin cancer

Related Stories

New findings explain how UV rays trigger skin cancer

October 18, 2017
Melanoma, a cancer of skin pigment cells called melanocytes, will strike an estimated 87,110 people in the U.S. in 2017, according to the Centers for Disease Control and Prevention. A fraction of those melanomas come from ...

German research advances in cancer and blood disorders reported in human gene therapy

October 18, 2017
Virotherapy capable of destroying tumor cells and activating anti-tumor immune reactions, and the use of engineered hematopoietic stem cells (HSCs) to deliver replacement genes that have the potential to cure blood diseases ...

Inflammation trains the skin to heal faster

October 18, 2017
Scars may fade, but the skin remembers. New research from The Rockefeller University reveals that wounds or other harmful, inflammation-provoking experiences impart long-lasting memories to stem cells residing in the skin, ...

Team finds a potentially better way to treat liver cancer

October 12, 2017
A Keck School of Medicine of USC research team has identified how cancer stem cells survive. This finding may one day lead to new therapies for liver cancer, one of the few cancers in the United States with an incidence rate ...

Scientists pinpoint surprising origin of melanoma

October 12, 2017
Led by Jean-Christophe Marine (VIB-KU Leuven), a team of researchers has tracked down the cellular origin of cutaneous melanoma, the deadliest form of skin cancer. The team was surprised to observe that these very aggressive ...

Bolstering fat cells offers potential new leukemia treatment

October 16, 2017
Killing cancer cells indirectly by powering up fat cells in the bone marrow could help acute myeloid leukemia patients, according to a new study from McMaster University.

Recommended for you

Drug yields high response rates for lung cancer patients with harsh mutation

October 18, 2017
A targeted therapy resurrected by the Moon Shots Program at The University of Texas MD Anderson Cancer Center has produced unprecedented response rates among patients with metastatic non-small cell lung cancer that carries ...

Possible new immune therapy target in lung cancer

October 18, 2017
A study from Bern University Hospital in collaboration with the University of Bern shows that so-called perivascular-like cells from lung tumors behave abnormally. They not only inadequately support vascular structures, but ...

Many pelvic tumors in women may have common origin—fallopian tubes

October 17, 2017
Most—and possibly all—ovarian cancers start, not in ovaries, but instead in the fallopian tubes attached to them.

Researchers find novel mechanism of resistance to anti-cancer drugs

October 17, 2017
The targeted anti-cancer therapies cetuximab and panitumumab are mainstays of treatment for advanced colorectal cancer, the second leading cause of cancer-related deaths in the United States. However, many patients have tumors ...

New bowel cancer drug target discovered

October 17, 2017
Researchers at the Francis Crick Institute have discovered a new drug target for bowel cancer that is specific to tumour cells and therefore less toxic than conventional therapies.

Using artificial intelligence to improve early breast cancer detection

October 17, 2017
Every year 40,000 women die from breast cancer in the U.S. alone. When cancers are found early, they can often be cured. Mammograms are the best test available, but they're still imperfect and often result in false positive ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.