Breast cancer news - (9/10/07)
A while back a study was published in the journal Cancer Epidemiology, Biomarkers & Prevention that showed an association between breast cancer risk and a western style diet in Asian women. Asian women have traditionally had lower rates of breast cancer, but their rates have been increasing. This study revealed two overall diet patterns - one consisting of a high amount of meat and candy, dessert, bread and milk termed ‘meat-sweet’. The other has mostly vegetables, soy-based products and freshwater fish and is called ‘vegetable-soy’. The researchers found that the ‘meat-sweet’ pattern was significantly associated with increased risk of estrogen-receptor-positive (ER+) breast cancer among overweight postmenopausal women.
A new gene was found to be associated with breast cancer by researchers at the University of Michigan Comprehensive Cancer Center. It is called FOXP3 and is located on the X chromosome - one of only 2 genes linked to cancer so far found there. In mice it was discovered that when the FOXP3 gene is silenced 90% of the them spontaneously developed cancerous tumors. In humans it was found that around 80% of the cancer tissues they studied didn’t express FOXP3 at all. They also discovered that FOXP3 represses the HER-2/ErbB2 oncogene which is associated with a more aggressive form of breast cancer.
The President of the International Menopause Society suggests that the connection between breast cancer incidence and use of hormone therapy needs to be looked at more closely in Breast cancer and hormone therapy — A looking-glass mirror?. He concludes with “breast-wise, in women younger than 60, HT (particularly estrogen-alone) is safe”.
In the Journal of the National Cancer Institute there was a study in July from the The Netherlands showing that “breast cancer detection may increase when mammograms are reviewed by both a radiologist and a mammographic technologist“. Specifically they found that “breast cancer detection rate increased 6.8% when the mammograms were read by two technologists and two radiologists”.
July 26, 2007
Breast cancer update - 7/26/07
A few short news bits concerning breast cancer:
Breast cancer and breast feeding
“Breastfeeding can offset the increased risk of invasive breast cancer for women who had their first full-term pregnancy after the age of 25, a study led by researchers at the University of Southern California (USC) suggests.” Read more.
Breast cancer vaccines
Someday vaccines may be developed that can help the body’s immune system to “stimulate an antibody and cellular response against cancer cells”. Some researchers trying to find a vaccine against breast cancer have a new strategy to boost T cells (a type of white blood cell) to fight against cancer cells. They used mice bred to carry the oncogene HER-2/neu and gave them a synthetic peptide vaccine. The vaccine resulted in all “samples either slowing or stopping the progression of breast cancer”. Read more.
Preoperative chemotherapy
A Cochrane Systematic Review indicates that “using chemotherapy to reduce the size of tumours before surgery does not compromise survival rates and enables women to retain better self-image and overall health because of the reduced impact of the surgery.” Read more.
More personalized treatment
A test may someday be available to help identify people who might react badly to radiation. “The research could mean people who might react badly to radiotherapy could be warned in advance or alternative treatments be sought.” Read more.
Abortion / miscarriage
And lastly - no surprises here: “Neither induced abortion nor spontaneous abortion (miscarriage) appears to be associated with breast cancer risk in premenopausal women”. Read more.
July 20, 2007
Breast cancer research update - 7/20/07
A few months ago it was discovered that four specific gene products are closely involved in breast cancer cells spreading (metastasize) into the lung. The work was published in PNAS and Nature.
The researchers took human breast cancer cells and using a technique called RNA interference they blocked the expression of each of these 4 genes individually and in different combinations. They then implanted these cancer cells into mice.
When any of the individual genes were inactivated the primary tumor growth and lung metastasis were inhibited a little. But when all four were inactivated - the tumor growth and spread into the lungs was almost completely stopped!
The four genes are:
- epiregulin - involved in the growth and progression of some cancers
- cyclooxygenase-2 (COX2) - involved in inflammation responses
- matrix metalloproteinase 1 (MMP1) - involved with angiogenesis and tumor cell migration
- matrix metalloproteinase 2 (MMP2) - involved with angiogenesis and tumor cell migration
.
Using drugs already available:
- celecoxib (Celebrex) - an inhibitor of COX2
- cetuximab (Erbitux) - and antibody against EGFR
- GM6001 - a broad MMP inhibitor (still in preclinical trials)
.
they were able to get the same results in the mice - almost all the primary tumor growth and metastasis were eliminated.
Future research will include investigating whether or not these four genes are involved in metastasis into other organs and if multidrug targeting of these gene products will be effective in people.
July 19, 2007
Breast cancer update - 7/16/07
A protein that is necessary for breast cancer to metastasize - or spread to other parts of the body - was recently discovered.
Akt1 is a serine-threonine protein kinase which inhibits apoptosis. Breast and some other cancers cells tend to make too much Akt1. A group of researchers at Thomas Jefferson University genetically engineered some mice so that they would no longer make Akt1.
They then bred these mice with mice that overexpressed the HER2/neu/ErbB2 gene. The HER2/neu/ErbB2 protein is a type of epidermal growth factor receptor. Around 25% or so of breast cancers overexpress this protein.
The researchers found mice that ended up with only one copy of the Akt1 gene developed only small and slow growing tumors. But those with 2 copies developed metastatic cancer.
They also found that Akt1 causes cancer cells to release a protein called CXCL16, a cytokine. CXCL16 helps breast cancer cells to migrate to other regions of the body.
These results - published in Proceedings of the National Academy of Sciences - may help in developing drugs that block Akt1 to prevent breast cancer metastases in the future.
July 12, 2007
Breast cancer update - 7/12/07
I’ll do some updates on breast cancer research next - there is lot of research out there, and with being so behind it will take a few postings to get caught up.
Treatment and Survival
According to the Journal of the National Cancer Institute the survival of women with early breast cancer is increased when chemotherapy is used along with tamoxifen although preventing the ovaries from releasing estrogen does not help.
A study in International Journal of Sports Medicine suggests that women who survived breast cancer and participated in an supervised cardiovascular and strength training program improved their cardiorespiratory fitness and strength and muscle function. All but the increases in cardiorespiratory fitness were retained another 8 weeks after the initial 8 week program concluded.
New Research
Transforming growth factor beta (TGF-beta) is a protein that is involved in proliferation and differentiation of cells. Radiation and chemotherapy treatments can increase circulating levels of TGF-beta as well as circulating cancer cells in mice. Research in a mouse model of breast cancer that was published in the Journal of Clinical Investigation shows that blocking TGF-beta could prevent metastases of a tumor. The researchers blocked TGF-beta with antibodies directed against it resulting in the prevention of tumor metastases. There are currently some early stage clinical trials involving TGF-beta inhibitors being added to the treatment regimen. Read more: Treatment-induced growth factor causes cancer progression
Prevention
Eating a lot of red and processed meats may increase the chances of women developing breast cancer according to some researchers in Great Britain. In this study the diets of over 35,000 women between 35 and 69 were analyzed and it was found that the postmenopausal women who ate the most red meat were 56% more likely to develop breast cancer and those who ate the most processed meat had a 64% increase. Why this is the case is not known but it may involve the saturated fat in meat or the heterocyclic amines and polycyclic aromatic hydrocarbons produced in grilled meat. This research was published in the British Journal of Cancer.
Angiogenesis is the process of new blood vessel development which can lead to the increase in growth of tumors by bringing them more nutrients. A protein called VEGF (vascular endothelial growth factor) is involved in this process. It has long been known that drinking alcohol by women increases their risk for breast cancer. A recent study by Dr. Jian-Wei Gu from the University of Mississippi Medical Center in mice showed that alcohol increased breast tumor size as well as increased blood vessel growth near the tumor. They also found evidence of an increase in VEGF levels.
That’s all for now! More breast cancer news coming soon.
March 29, 2007
Breast cancer - detection and treatment updates
New detection method being developed
Researchers at Harvard Medical School are working on a method to distinguish between malignant tumors and benign masses in breast tissue. Malignant breast tumors have a higher percent of a calcium salt called hydroxyapatite, while in benign tumors there is more calcium oxalate. The researchers are developing a contrast agent that binds just to the calcium salt in the malignant tumors and then using optical tomography they can “reconstruct a three-dimensional image of tissues deep inside the breast”. Unfortunately human trials are still a few years away but when or if it becomes available for use it will be especially helpful for women with more dense breasts whose cancer is difficult to detect with mammograms.
New recommendations for women with cancer found in one breast
A big story this week has been the new recommendation that women with a recent diagnosis of cancer in one breast should have an MRI of their other breast. In their study 3.1% of women with cancer in one breast were found to have cancer in their other breast even though a mammogram didn’t previously detect it.
Other News
Women whose breast cancer is negative for the three significant markers - 1) estrogen receptor (ER), 2) human epidermal growth factor receptor 2 (HER2), and 3) progesterone receptor (PR) - sometimes referred to as “triple negative” cancers are more likely to be African American or Hispanic, under 40 years old, with a lower socioeconomic status. These types of tumors are more likely to be aggressive and deadly.
A study at the University of Michigan Comprehensive Cancer Center shows that 44% surgeons “do not refer the majority of their breast cancer patients to a plastic surgeon prior to the initial surgery”. Older women in the UK may not be getting the best treatment for breast cancer according to a study in the British Journal of Cancer. They seem to have a lower chance of receiving primary surgery, undergoing axillary node surgery and undergoing steroid receptor tests, lowering their odds of survival.
March 19, 2007
Recent developments in breast cancer research
According to research by Mary Ann Gilligan and published in the American Journal of Public Health women who have surgery for breast cancer in a hospital that has done a lot of them are 20% less likely to die from breast cancer within 5 years
Women who had radiation for breast cancer in the 1970’s and 80’s have a 35-40% greater chance of having heart disease within 20 years. Women who smoked had a even greater risk of heart attack. In addition women who had chemotherapy along with the radiation had a even higher risk of heart disease.
The FDA recently approved the use of GlaxoSmithKline’s Tykerb for women with HER-2 positive advanced breast cancer in combination with the oral chemotherapy drug, Xeloda (capecitabine) who are not responding to Herceptin anymore.
Researchers at the University of British Columbia recently announced in the Public Library of Science the discovery that a protein called podocalyxin changes the shape and adhesive quality of tumor cells. Further research may designing antibodies to block the function of the protein to help fight metastasizing cancer.
February 12, 2007
Breast cancer - genes, tests and drugs
A team led by Angela Cox of Sheffield University Medical School in the UK recently published in Nature Genetics the discovery of a gene that appears to decrease the chance of getting breast cancer in women of European descent by around 13%. The utilized data collected from 14 studies involving around 33,000 women. The gene is called CASP8 and is a member of the cysteine-aspartic acid protease family of genes also known as caspases. Caspases are involved in apoptosis, which is the programmed death of certain cells. Many cancers involve mutations in genes that are involved with apoptosis resulting in cancerous cells remaining alive despite having mutations that should have resulted in their dying through apoptosis.
Recently the FDA approved a test that can help predict whether or not women who have had breast cancer before are likely to have it return. The test is called MammaPrint and uses a sample from the person’s breast cancer. DNA from the sample is then analyzed and the activity of about 70 different genes are measured.
A report in Cancer finds that some newer breast cancer drugs called aromatase inhibitors are safer and have less side effects than tamoxifen and their users tend to live longer. They only for women who are post-menopausal however. Aromatase inhibitors block the activity of the enzyme aromatase thereby preventing the conversion of androgens into estrogens.
(Technorati Tags: breast cancer, apoptosis, cancer, tamoxifen, aromatase inhibitors)
January 23, 2007
Breast cancer - exercise, obesity and tamoxifen
A study published a while back in Archives of Internal Medicine presented evidence that women who exercise regularly may have a reduced risk of developing breast cancer, especially the most aggressive types. Data collected from over 36,000 women from the Iowa Women’s Health Study over an 18 year period showed that women who were the most active had a 14% less chance of developing breast cancer. And their chance of developing estrogen only receptor postitive (no progesterone receptors) cancer went down 33%.
If that’s not reason enough to exercise regularly a different study in the Journal of Clinical Oncology suggests that women who have breast cancer and are obese (or less well educated) are less likely to get an optimal dose of chemotherapy. It was found that 21% of the women who were obese only got 85% or less of the regular dose of chemotherapy based on their weight. Also women who did not graduate from high school also got a lower dose than they should have.
The same issue also reports that women who choose their breast cancer surgeon themselves tend to pick more experienced surgeons than women whose doctor is picked by another doctor or by their health insurance. In general patients who have doctors with more experience tend to do better.
More recently in the New England Journal of Medicine some Canadian researchers discovered that women who have more dense breasts - and more difficult to get accurate mammograms from - had a greater chance of getting cancer. And a more aggressive type of cancer yet. There is not yet a way to test how dense a person’s breasts are.
Tamoxifen is a drug used to fight estrogen receptor postitive breast cancers. The journal Cancer reports that many women stop taking it before the recommended 5 years are over. Apparently 22% stopped before one year, 28% by two years and 35% by three and a half years. The women who were most likely to stop taking it were the youngest and oldest in the group.
(Technorati Tags: breast cancer, tamoxifen, exercise, estrogen)
January 2, 2007
More breast cancer news
It hasn’t been that long since I posted an update about breast cancer - but there is already a lot more to post about!
A paper in the Archives of Internal Medicine presents data from 116,000 women shows that those who have infertility issues due to an ovulation disorder also have a lower incidence of breast cancer - 25% less. Of course it is just a correlation, but indicates that there may be no long term consequences to infertility treatment as the risk was lowest in the women who had been treated for infertility with induced ovulation.
Another correlational study supports the previous evidence that weight gain increases the risk of breast cancer. This one was published in the International Journal of Cancer and states that there is around a 70% increase in the chance of developing breast cancer in women who gained more than 60 lbs between ages 20 and menopause. This is in contrast to women who gained no more than 20 lbs. over the same period.
The Journal of the National Cancer Institute has a report on 2437 women who have survived breast cancer - those who decreased their fat intake after treatment by around 40% had a lower return of cancer than those who didn’t. The effect may be due to the weight loss that went along with the fat intake reduction rather than the reduced fat level itself. Also, women with estrogen receptor-negative breast cancer may see the effect more than women with estrogen receptor-positive cancers.
Along those same lines, another study published in the Archives of Internal Medicine suggests that women who eat more red meat have a greater chance of developing estrogen receptor-positive breast cancer. Specifically, those who ate greater than 1.5 servings of red meat on an average day had nearly twice the chance of getting cancer than women who only had 3 or less servings in a week. This effect could be due to either hormone residues, iron or other carcinogens in the meat.
A few weeks ago Science published a report that shows that one of the active ingredients in the pill RU-486 may also help to stop the formation of breast cancer in mice with the BRCA-1 mutation. Progesterone can stimulate the development of breast cancer since it accelerates cell division. However, mifepristone (one of the ingredients in RU-486) blocks the action of progesterone.
There is lots more research out there - but I’m out of time today! I’ll try to keep my blog updated as much as possible with new research.
(Technorati Tags: breast cancer, brca-1, red meat, fat)
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