Posts Tagged ‘medicine’

Increase seen in use of double mastectomy, although not associated with reduced death

Randomized trials have demonstrated similar survival for patients with early-stage breast cancer treated with breast-conserving surgery and radiation or with mastectomy. However, previous data show increasing use of mastectomy, and particularly bilateral mastectomy (removal of both breasts) among U.S. patients with breast cancer. Evidence for a survival benefit with this procedure appears limited to rare patient subgroups. “Because bilateral mastectomy is an elective procedure for unilateral breast cancer [in one breast] and may have detrimental effects in terms of complications and associated costs as well as body image and sexual function, a better understanding of its use and outcomes is crucial to improving cancer care,” according to background information in the article.

Allison W. Kurian, M.D., M.Sc., of the Stanford University School of Medicine, Stanford, Calif., and colleagues used data from the California Cancer Registry from 1998 through 2011 to compare the use of and rate of death after bilateral mastectomy, breast-conserving therapy with radiation, and unilateral mastectomy (removal of one breast).

The analyses included 189,734 patients. The researchers found that the rate of bilateral mastectomy increased from 2.0 percent in 1998 to 12.3 percent in 2011, an annual increase of 14.3 percent. The increase in bilateral mastectomy rate was greatest among women younger than 40 years: the rate increased from 3.6 percent in 1998 to 33.0 percent in 2011, increasing by 17.6 percent annually. Use of unilateral mastectomy declined in all age groups

Bilateral mastectomy was more often used by non-Hispanic white women, those with private insurance, and those who received care at a National Cancer Institute-designated cancer center; in contrast, unilateral mastectomy was more often used by racial/ethnic minorities and those with public/Medicaid insurance.

Compared with breast-conserving surgery with radiation, bilateral mastectomy was not associated with a mortality difference, whereas unilateral mastectomy was associated with higher mortality.

“In a time of increasing concern about overtreatment, the risk-benefit ratio of bilateral mastectomy warrants careful consideration and raises the larger question of how physicians and society should respond to a patient’s preference for a morbid, costly intervention of dubious effectiveness,” the authors write.

“These results may inform decision-making about the surgical treatment of breast cancer.”

Editorial: Contralateral Prophylactic Mastectomy: Is It a Reasonable Option?

In an accompanying editorial, Lisa A. Newman, M.D., M.P.H., of the University of Michigan, Ann Arbor, discusses the issues involved with the use of contralateral prophylactic mastectomy (risk-reducing mastectomy for the unaffected breast).

“The need for patients to be accurately informed regarding safe and oncologically acceptable treatment options is indisputable. The dense fog of complex emotions that accompanies a new cancer diagnosis can impair the ability to process this information. Patients should be encouraged to allow the intensity of these immediate reactions to subside before committing to mastectomy prematurely. Physicians should not permit excessive treatment delays to compromise outcomes, but the initial few weeks surrounding the diagnosis are more effectively utilized by time invested in patient education and procedures that contribute to comprehensive treatment planning as opposed to hastily coordinating impulsive, irreversible surgical plans.”

source : http://www.sciencedaily.com/releases/2014/09/140902171150.htm

Is the HPV vaccine necessary?

“I often have parents ask me if their child should get the HPV vaccine and what are my thoughts about giving it. Some parents are concerned it will promote sexual activity, others think it is unnecessary and others think their child is too young. If the child falls between the recommended ages given by the American Academy of Pediatrics I strongly recommend the vaccination. It really could be the difference between life and death,” said Hannah Chow-Johnson, MD, pediatrician at Loyola University Health System and assistant professor in the Department of Pediatrics at Loyola University Chicago Stritch School of Medicine.

According to Chow there are only two shots that can prevent cancer. One is hepatitis B and the other is the Human Papilloma Virus (HPV) vaccine. HPV is the most common sexually transmitted disease and is known to cause several different types of cancer, including cervical cancer, which is the second leading cancer-cause of death in women.

“Parents need to take into consideration the anti-cancer benefits when considering if they want their child to receive the HPV vaccine,” said Chow.

According to the Centers for Disease Control and Prevention there are more than 20 million people in the U.S. infected with HPV and at least half of these are between the ages of 15-25.

HPV is transmitted through intercourse and genital contact. Both men and women can harbor the virus, which can remain in a person for years after the initial infection.

“One of the scary aspects of HPV is that a person can be infected and not even know it. He or she may have no symptoms at all and still be spreading the virus,” Chow said. “This is why I strong believe in vaccinating males and females early, well before any exposure takes place.”

Prevention is critical when it comes to HPV. According to Chow the vaccine’s protection rate is 93 percent when given before any exposure. After exposure the vaccine doesn’t treat pre-exiting viruses but will help protect against future exposure.

“HPV is a very dangerous virus that can lead to death. Since there is no cure, prevention is all the more important. This vaccine could save the life of your child,” Chow said.

source : http://www.sciencedaily.com/releases/2014/08/140828135242.htm

Circulating tumor cell clusters more likely to cause metastasis than single cells

“While CTCs are considered to be precursors of metastasis, the significance of CTC clusters, which are readily detected using devices developed here at MGH, has remained elusive,” says Shyamala Maheswaran, PhD, of the MGH Cancer Center, co-senior author of the Cell paper. “Our findings that the presence of CTC clusters in the blood of cancer patients is associated with poor prognosis may identify a novel and potentially targetable step in the blood-borne spread of cancer.”

In their experiments the team used two versions of a microfluidic device called the CTC-Chip — both developed at the MGH Center for Engineering in Medicine — that captures CTCs from blood samples in ways that make the cells accessible for scientific testing. One version — the HBCTC-Chip — can efficiently capture extremely rare CTCs in a blood sample. Another version, the CTC-iChip, rapidly isolates CTCs in a way that does not rely on preidentified tumor antigens, allowing capture of cells with gene expression patterns that may be missed by the antibodies used in the HBCTC-Chip.

A series of experiments in animal models of breast cancer revealed that:

  • CTC clusters are made up of cells that probably were adjacent to each other in the primary tumor, not cells that proliferated after entering the bloodstream.
  • Although CTC clusters make up only 2 to 5 percent of all CTCs, they contributed to around half of lung metastases resulting from implanted breast tumors, indicating a metastatic potential 23 to 50 times greater than single CTCs.
  • CTC clusters injected into mice survived in greater numbers than did single CTCs, and metastases developing from clusters led to significantly reduced survival.
  • CTC clusters disappear from the animals’ bloodstreams more rapidly than do single CTCs, probably because they become lodged in capillaries where they give rise to metastases.

Analysis of blood samples taken at several points in time from a group of patients with different forms of advanced metastatic breast cancer found CTC clusters in the blood of 35 percent of patients and that the survival of those with more clusters in their blood was significantly reduced. Similar analysis of samples from a group of prostate cancer patients also found an association between the presence of CTC clusters and dramatically reduced survival.

RNA sequencing of both single and clustered CTCs from breast cancer patients identified several genes expressed at elevated levels in CTC clusters, one of which — a protein called plakoglobin — also was overexpressed in the primary tumors of patients with reduced survival. Analysis of blood and tissue samples from one patient revealed that plakoglobin was expressed in CTC clusters but not single CTCs and also was expressed in some portions of both the primary tumor and metastases. Plakoglobin is a component of two important structures involved in cell-to-cell adhesion, and the investigators found that suppressing its expression caused CTC clusters to fall apart, reducing their metastatic potential, and also disrupted cell-to-cell contact between breast cancer cells but not normal breast tissue.

“It is possible that therapeutically targeting plakoglobin or pathways involved in cell-to-cell adhesion within cancer cells could be clinically useful, especially in patients in whom CTC clusters are found,” says Nicola Aceto, PhD, of the MGH Cancer Center and lead author of the Cell paper. “We need to investigate that possibility along with determining whether further characterization of both single CTCs and CTC clusters will provide further insight into differences in their biology, drug responsiveness and their contribution to the process of metastasis.”

source : http://www.sciencedaily.com/releases/2014/08/140828135519.htm