News from the world of breast cancer and cancer, as highlighlighted by Google Alerts, for the week ending 23 May 2014.
It seems there’s been a rise in the number of women opting for double mastectomies, because of fear of recurrence, even when there is no genetic basis for breast cancer (i.e. no BRCA1/2 gene mutation].
I can understand and sympathise: After all, who wants to go through the rollercoaster of breast cancer diagnosis and treatment again if it recurs in the other breast? Why not get it all out in one go, with an increased chance that it won’t ever return? There are other reasons women opt for contralateral mastectomies: the need for symmetry is one.
But mastectomies carry risks and psychological consequences. Furthermore, what the surgeons don’t tell patients is that the cancer can still return, mastectomy or no double mastectomy, in the same breast with the tumour. The cancer cells lurk in the scar tissue, which is often the site of a recurrence. This can happen even if patients have had radiotherapy and chemotherapy.
There are no guarantees with a mastectomy or breast cancer treatment. Women may be under the impression that a mastectomy will minimise their chances of getting breast cancer or of it returning, but it’s never as simple or straightforward as that. I’ve had friends who’ve gone through mastectomies only for the cancer to recur in the same breast.
On a more positive note, there are two new developments in HER2 cancer. Also more coverage on dogs sniffing cancer, a favourite topic I’ve covered in other Best of Breast posts. Dogs can now sniff cancer with 90% accuracy. We’re talking ovarian cancer, for which no known early-detection test [like a mammogram] exists. If there is a machine that can do that now, raise your hands. Scientists keep trying to invent machines to replicate the skills of dogs, but these machines are few, and years down the road. But when people’s lives are at stake through accurate and fast diagnosis, waiting is impractical – they’ve proven themselves, let’s get the dogs in now.
1. Contralateral prophylactic [double] mastectomy often used unnecessarily
- Fear of recurrence drove many women with breast cancer to consider or undergo contralateral prophylactic mastectomy even when they were not at significant risk for contralateral occurrence, according to an analysis of SEER data.
- “Women appear to be using worry over cancer recurrence to choose contralateral prophylactic mastectomy,” researcher Sarah Hawley, PhD, MPH, associate professor of internal medicine at the University of Michigan Medical School, said in a press release.
- “This does not make sense, because having a non-affected breast removed will not reduce the risk of recurrence in the affected breast.
- For women who do not have a strong family history or a genetic finding, we would argue it’s probably not appropriate to get the unaffected breast removed.”
- In the UK, leading breast cancer surgeon Professor Kefah Mokbel said in the past ten years there have been increasing requests for double mastectomies and reconstruction from young women diagnosed with cancer in one breast.
- He said: ‘They want to minimise the risk, but the study shows that women who do not have a genetic predisposition or family history are being over-treated.’
- Genetic testing should be used as an objective measure for women considering having a second unaffected breast removed, he said.
- He warned that the procedure carries complications, such as potential psychosexual problems and possible delay in medical treatment of the affected breast, which could reduce chances of survival.
For more information:
- Rosenberg SM. JAMA Surg. 2014;doi:10.1001/jamasurg.2013.5713.
- Hawley ST. JAMA Surg. 2014;doi:10.1001/jamasurg.2013.5689.
2. Virologists harness adenovirus to kill HER-2 breast cancer cells
- The HER2 oncogene is implicated in 20 to 30 percent of breast cancers and has a poor prognosis.
- Current therapy for HER2 cancers (Herceptin and chemotherapy) is not enough to combat this deadly cancer and cannot treat a substantial number of cases.
- The adenovirus is a common virus, and researcher Maurice Green, Ph.D., chair of SLU’s Institute for Molecular Virology, has studied it for years. He hopes to tame the virus’s abilities to kill cancer cells in order to use it as a therapy.
- Now, Green and colleague Paul Loewenstein, assistant research professor in the department, have found that a small region of the E1A protein, an adenovirus gene, is capable of repressing HER2 cell growth.
- Significantly, this function appears to be controlled by the first 80 amino acids (E1A 1-80) of the entire E1A oncogene.
- This is a promising finding, because it means that researchers can focus on this small region of the adenovirus without delving into the rest of the E1A oncogene, which has other functions.
- Remarkably, the expression of these 80 amino acids efficiently represses HER2 transcription and kills breast cancer cells but not normal cells.
- “This is probably due to the need of the tumor cells for continued overexpression of the HER2 oncogene for growth and survival. This phenomenon has been termed ‘oncogene addiction,'” Green said.
- One of the exciting possibilities of E1A 1-80 is that it seems to be effective against cancer cells over-expressing other HER family members, besides HER2.
- Potentially, E1A 1-80 could be used against tumors of the prostate, ovaries, colon, and head and neck, as well as breast cancer.
For more information: Saint Louis University: http://www.slu.edu/x94342.xml
3. New breakthrough in fight against treatment-resistant HER-2 positive cancer
- The drug Herceptin is a treatment of choice for many women with HER2-positive breast cancer, but in most cases, resistance to the treatment develops within several years.
- The prognosis for HER2-positive breast cancer patients is worse than for those with other subtypes of the illness.
- A multi-institution team led by CSHL Professor Nicholas Tonks reported that it has found a means of inhibiting another protein, called PTP1B, whose expression is also upregulated in HER2-positive breast cancer.
- Dr. Tonks discovered PTP1B some 25 years ago. It is an enzyme – one in a “superfamily” of 105 called protein tyrosine phosphatases (PTPs) — that perform the essential biochemical task of removing phosphate groups from amino acids called tyrosines in other proteins.
- Adding and removing phosphate groups is one of the means by which signals are sent among proteins.
- PTP1B has been shown to play a critical role in the development of tumors in which HER2 signaling is aberrant.
For more information: Nature Chemical Biology, doi:10.1038/nchembio.1528, “Targeting the disordered C terminus of PTP1B with an allosteric inhibitor”
4. Dogs’ Cancer-Sniffing Ability Offers 90%-Plus Accuracy
- The largest study ever done on cancer-sniffing dogs found they can detect prostate cancer by smelling urine samples with 98 percent accuracy.
- At least one application is in the works seeking U.S. approval of a kit using breath samples to find breast cancer.
- When dogs sniff for cancer, they are detecting the chemicals emitted by a tumor.
- These chemicals are referred to as volatile organic compounds, or VOCs.
- VOCs have been found in the breath of lung cancer patients and colon cancer patients, as well as in the urine of prostate cancer patients.
- In 2009, Zaphiris, a dog trainer for 25 years with an extensive list of celebrity clients and an education in biology, founded the In Situ Foundation, a nonprofit organization that trains cancer-sniffing dogs and conducts research in the field.
- Her organization is in the process of submitting an FDA application for approval of a canine medical scent detection kit.
- In her system, patients exhale through a tube on to a cloth, which captures molecules, or VOCs, of a malignancy.
- Trained dogs would then sniff the cloths for their presence.
- The dog screening would be an “early warning test,” she said, possibly used in connection with a mammogram for reviewing results before proceeding to a biopsy.
Australian Shepherd, Stewie, the thorough and meticulous cancer detection dog, detecting ovarian cancer
- “You should see the amount of e-mails I get saying ‘I got an unclear mammogram and I don’t know if I want a biopsy so could I have dogs screen my breath sample?’,” Zaphiris said.
- Zaphiris said the medical system shouldn’t wait for the development of technology that can accurately sense cancer with the ability of a dog.
- Her goal is to open canine scent detection centers that will make her animals accessible beyond just their use for research.
- “If there is a machine as accurate as a dog, I say do it,” Zaphiris said. “It’s highly impractical to wait until the machines can catch up.”
5. Yale Cancer Center studies find lifestyle changes improve biomarkers for breast cancer recurrence and mortality
- A pair of Yale Cancer Center interventional studies involving breast cancer survivors found that lifestyle changes in the form of healthy eating and regular exercise can decrease biomarkers related to breast cancer recurrence and mortality.
- The abstracts are scheduled to be presented at the 2014 annual meeting of the American Society of Clinical Oncology in Chicago May 30-June 3rd.
- The abstracts are:
- Effect of weight loss intervention on inflammatory and metabolic markers in breast cancer survivors. The lifestyle, exercise, and nutrition (LEAN) study. (#1505)
- Effect of exercise on weight, body fat, and serum inflammatory biomarkers in breast cancer survivors with aromatase inhibitor arthralgias (joint pain): The hormones and physical exercise (HOPE) study. (#9356)
6. Scientists discover new mechanism which causes breast cancer metastasis
- Scientists at Queen Mary University of London (QMUL) have uncovered a new mechanism which makes breast cancer cells move and invade the body, a discovery which could shed light on how to treat particularly aggressive forms of breast cancer and stop it spreading and recurring.
- The study – published in the journal Nature Communications and led by QMUL’s Barts Cancer Institute – investigated the role of a molecule called ‘c-Met’ which is present in almost a third of breast cancer patients and is known to make breast cancer cells move, and therefore spread, around the body. This process is known as metastasis and is a major cause of treatment failure and cancer death.
- When looking at aggressive breast cancer cells, the researchers found that c-Met acted differently to normal and ‘switched on’ another important molecule (known as ‘Rac’), from a specific location inside the cell, instead of from the cell surface, as previously thought. This signalling inside the cell is necessary to trigger the cancer cells movement.
For more information: “Receptor tyrosine kinase c-Met controls the cytoskeleton from different endosomes via different pathways.” Ludovic Ménard, et al. Nature Communications 5, Article number: 3907 DOI: 10.1038/ncomms4907.