Research matters

zoom

News from the Harvard Medical School research community.

Oncology

Drug combination shrinks breast cancer metastases in brain

A combination of a 'targeted' therapy and chemotherapy shrank metastatic brain tumours by at least 50% in one-fifth of patients with aggressive HER2-positive breast cancer, according to data presented by Dana-Farber Cancer Institute investigators at the San Antonio Breast Cancer Symposium.

Lapatinib (Tykerb) and capecitabine (Xeloda) were paired in an extension of a Phase 2 clinical trial in which lapatinib given alone shrank brain metastases significantly in 6% of 241 patients.

In the extension trial, capecitabine was added to lapatinib in 49 patients whose metastases - cancerous colonies in the brain spread from their primary cancer - had progressed while on treatment.

With the combination therapy, brain metastases shrank by 20% or more in 18 patients (37%) and shrank by at least 50% in 10 patients (20%), reported Nancy Lin, MD, of Dana-Farber's Breast Oncology Center.

"Very few medications have shown activity in the treatment of brain metastases, particularly in HER-2-positive metastatic breast cancer patients," said Lin, who led the study with Eric Winer, MD, director of the Dana-Farber Breast Oncology Center.

"Therefore, these data are quite encouraging, and further studies are warranted."

Lapatinib is an oral small-molecule drug from GlaxoSmithKline that is approved along with capecitabine for treating patients with advanced or metastatic breast cancer whose tumours are driven by the abnormal growth signal, HER-2, and who have already undergone therapy including trastuzumab (Herceptin), a taxane drug, and an anthracycline compound. Lapatinib, like trastuzumab, blocks the HER-2 signal.

Up to one-third of women with advanced, HER-2-positive breast cancer may develop metastases to the brain.

"Although radiation treatment is often effective, as women live longer with metastatic cancer, some develop worsening of brain metastases despite radiation," said Lin.

"Because cancer in the brain can have a major impact on quality of life, it is important to have treatment options to address this problem."

Neurobiology

Neurons in the frontal lobe may be responsible for rational decision-making

Scientists have found that when monkeys choose between different options, the value neurons assign to each option does not depend on the menu of choices.

You study the menu at a restaurant and decide to order the steak rather than the salmon. But when the waiter tells you about the lobster special, you decide lobster trumps steak

Without reconsidering the salmon, you place your order-all because of a trait called 'transitivit'y.

"Transitivity is the hallmark of rational economic choice," says Camillo Padoa-Schioppa, a postdoctoral researcher in HMS Professor of Neurobiology John Assad's lab.

According to transitivity, if you prefer A to B and B to C, then you ought to prefer A to C. Or, if you prefer lobster to steak, and steak to salmon, then you will prefer lobster to salmon.

Padoa-Schioppa is lead author on a paper that suggests this trait might be encoded at the level of individual neurons.

The study, which appeared online Dec. 9 in Nature Neuroscience, shows that some neurons in a part of the brain called the orbitofrontal cortex encode economic value in a "menu invariant" way.

That is, the neurons respond the same to steak regardless if it's offered against salmon or lobster.

"People make choices by assigning values to different options. If the values are menu invariant preferences will be transitive."

"The activity of these neurons does not vary with the menu options, suggesting that these neurons could be responsible for transitivity," Padoa-Schioppa explains.

"This study provides a key insight into the biology of our frontal lobes and the neural circuits that underlie decision-making," Assad adds.

"Despite the maxim, we in fact can compare apples to oranges, and we do it all the time. Camillo's research sheds light on how we make these types of choices."

Print | Email | Discuss this article |

USER COMMENTS (0 COMMENTS)

POST A COMMENT

CLICK HERE TO POST A COMMENT

Add your Comment All posts are sent to the administrator for review and are published only after approval. ArabianBusiness.com reserves the right to remove any comment at any time for any reason. Please keep your responses appropriate and on topic.
Name *
Remember me on this computer
Email *	(Your email address will not be published)
City
Country
Subject *
Comment *
Notify me of further comments
Security Code *
Please click post only once - your comment will not be published immediately.