Posted tagged ‘breast cancer’

Stanford study provides new understanding of breast growth disorders

May 4, 2017

Photo by sasint

Breast underdevelopment at puberty is associated with a shortage of several hormones produced by the pituitary gland, a condition called combined pituitary hormone deficiency (CPHD). This disorder is caused in part by loss-of-function mutations of the GLI2 gene, but the molecular pathways of how CPHD manifests are not fully understood.

Now, researchers at Stanford University School of Medicine have discovered a new way that GLI2 impacts breast development, as recently reported in Science. Led by Philip Beachy, PhD, a Stanford professor of developmental biology and of biochemistry, the research team found that GLI2 activity helps control mammary stem cells in mice.

Stem cells are responsible for the growth, homeostasis and repair of many tissues. The behavior and survival of these stem cells depends on their local microenvironment, called a stem cell niche. During breast growth, the niche must support its associated stem cells while also responding to circulating hormones that trigger the dramatic changes of puberty.

The study showed that this stem cell niche is genetically programmed to produce the signals that control breast development in response to the hormones that regulate puberty. Using mice without a functioning GLI2 gene, the researchers found that a defective stem cell niche environment may lead to the breast growth defects seen in human CPHD. In addition, the research provides insights into a new mechanism to target when developing drugs that may help prevent breast cancer.

The authors conclude:

“Whereas prior studies implicate stem cell defects in human disease, this work shows that niche dysfunction may also cause disease, with possible relevance for human disorders and in particular the breast growth pathogenesis associated with combined pituitary hormone deficiency.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

 

Advertisements

Genomic screening may help predict breast cancer survival

March 21, 2017

Photo by 3dman_eu

Breast cancer patients are often faced with a difficult decision at the end of their primary treatment: Should they get systemic adjuvant therapy, such as the anti-estrogen drug tamoxifen? Such therapies lower the risk that the cancer will come back, but they also carry the risk of potentially serious side effects.

What would be helpful is for physicians to have a way to predict which patients have the best prognosis and might not need adjuvant therapy. Now, researchers from the Lawrence Berkeley National Laboratory may have a solution, according to a study recently published in Oncotarget.

The research team analyzed clinical patient data and large genomic datasets of normal and tumor breast tissues — identifying 381 genes associated with the relapse-free survival of breast cancer patients. With further analysis, they were able to develop a scoring system based on a 12-gene signature that predicts breast cancer survival. Patients with a low score were more likely to live longer.

Senior author Antoine Snijders, PhD, a research scientist at Berkeley Lab, explained in a recent news release:

“Distinguishing patients with good prognosis could potentially spare them the toxic side effects associated with adjuvant therapy. Determining prognosis involves a range of other clinical factors, including tumor size and grade, the degree to which the cancer has spread, and the age and race of the patient. Our scoring system was predictive of survival independent of these other variables.”

The study showed that their 12-gene signature was effective at predicting patient survival for two specific subtypes of breast cancer — luminal-A and HER2 — but it wasn’t effective for other subtypes.

In addition, the researchers identified seven genes as potential tumor suppressors that could be targeted when developing new breast cancer therapies. They hope that their work will help doctors and patients make more informed treatment decisions, as well as help others develop better breast cancer drugs.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Education reduces anxiety about mammography

January 8, 2016
Woman received mammogram (Rhoda Baer)

Woman receives mammogram (Rhoda Baer)

My close childhood friend Kelly died from breast cancer when she was only 32 years old. This inspired me to choose a research position at Berkeley Lab to help develop new breast-imaging scanners to improve early detection. Given my expertise in this field, my friends come to me with their confusion and ask, “At what age and how frequently should I get a mammogram?”

There has been a lot of debate surrounding mammography screening since 2009 when the United States Preventive Services Task Force revised their guidelines for average-risked women, limiting routine screening to biennial mammography for women 50 to 74 years of age.

The task force recommended increasing the screening age in part due to the harmful anxiety caused by false-positive results, which are more common in younger women. The American Cancer Society recently released a new set of guidelines that recommends yearly mammograms starting at age 45, but they also considered the pain, anxiety and other potential side effects of mammography.

A recent article published in the Journal of the American College of Radiology describes a successful intervention to reduce this anxiety. The authors provided interactive one-hour educational sessions on mammography, which were led by a trained breast radiologist.

Before the lecture, a questionnaire was administered to the participants to identify their anxiety and previous mammography experience — 117 responded. Those respondents who reported having anxiety about mammography screening indicated “unknown results” and “anticipation of pain” as the primary sources of their anxiety.

A follow-up questionnaire measured the effectiveness of the informational sessions. Virtually all participants were able to correctly answer key facts that were covered in the lecture, such as recognizing that it is important to have your prior mammogram available to the radiologist for comparison.

The journal article concludes:

Attendees of these sessions reported high levels of satisfaction in their participation, with a strongly favorable impact on increased knowledge and decreased anxiety (“harm”). Education can enable women to share in informed decision making regarding if, when, and how often to attend screening mammography. Attendees also reported encouragement to attend screening mammography.

The authors hope to encourage other radiologists to provide similar proactive, public outreach education.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Why Don’t We Get Cancer More Often?

April 9, 2012

See my KQED Quest blog on Dr. Mina Bissell’s pivotal breast cancer research at Lawrence Berkeley National Lab. She will be part of a free public lecture, Science at the Theater: Health Detectives. It will be held on April 23 at 7 pm at the Berkeley Repertory Theater.

science at the theater health detectives

Image courtesy of Friends of Berkeley Lab.

Risk of Invasive Breast Cancer Predicted

May 4, 2010

Way too many of my women friends have suffered through breast cancer diagnosis, starting with a close friend who died of breast cancer in her early 30s. Her death inspired me to change careers, in hopes of developing better ways to detect and stage breast cancer. Although the focus of my work has now moved on to other medical imaging areas, I still pay particular attention to new breast cancer research.

It seems like there are reports on breast cancer research in the news daily. But my eye was particularly caught by an article published online on April 28, 2010 in the Journal of the National Cancer Institute. A group of researchers, from UCSF Helen Diller Family Comprehensive Cancer Center, are now able to predict whether women with ductal carcinoma in situ are at high or low risk of developing subsequent invasive cancer.

Ductal carcinoma in situ (DCIS) is the most common type of non-invasive breast cancer. The American Cancer Society estimates that about 60,000 women are diagnosed with DCIS in the U.S. each year. This cancer starts in the milk ducts. It is called non-invasive because it hasn’t spread beyond the milk ducts into any normal surrounding breast tissue. DCIS isn’t life-threatening and it rarely leads to death from breast cancer, but having DCIS can increase your risk of developing an invasive breast cancer in the future. Approximately 11 out of 100 women diagnosed with DCIS and treated with a lumpectomy only go on to develop invasive cancer within 8 years, and about the same number go on to develop subsequent DCIS within 8 years. That means that the majority of such women have no further tumors, but these women typically still go through some form of aggressive treatment.

So we really need a way to predict which women with DCIS have a high risk of developing subsequent tumors. The UCSF scientists report that they’ve discovered a method to do just that. They collected and analyzed data for 1162 women aged 40 years or older, who were diagnosed with DCIS and treated with a lumpectomy alone in the San Francisco Bay Area. They followed and measured clinical, histopathologic, and molecular characteristics of subsequent tumors for this large population (from 63 hospitals) for 8 years.

They found that the risk of subsequent invasive cancer was significantly increased among women whose initial DCIS was detected by palpation compared with those detected by mammography. They also found that DCIS lesions that were “triple positive” for the expression of biomarkers p16COX-2and Ki67 had an even higher risk of subsequent invasive cancer. However, these factors were not associated with increased risk of subsequent DCIS. An independent set of biomarker expression and conditions was identified for increased risk of subsequent DCIS, with the lowest risk group having disease-free surgical margins of 10 mm or larger.

Based on their findings, the UCSF scientist were able to stratify the women into 4 categories for risk of subsequent invasive cancer — Lowest (17%), Low (27%), Intermediate (28%) and High (28%). The lowest risk group had only a 4% risk of developing invasive cancer within 8 years, whereas the high risk group had a 20% risk. A similar stratification was performed for risk of subsequent DCIS with similar results.

Hopefully this new method of predicting risk for subsequent cancers will help women with DCIS chose the proper treatment. Karla Kerlikowske, the lead author, states “It will lead to a more personalized approach to treatment. As many as 44 percent of the patients (i.e., lowest and low risk groups) with DCIS may not require any further treatment, and can rely on surveillance.”


%d bloggers like this: