Photo by: Mass Communication Specialist 2nd Class Joseph Moon (U.S.Navy) via Wikimedia Commons

Because of lesser chances to detect cancerous breast lumps in overweight or obese women, doctors recommend more frequent mammograms for women with weight problems.A Swedish study found that such women are more likely to have a larger tumor when it is detected during the procedure or between screenings.

The research by the Karolinska Institute had 2,012 women volunteers who were breast cancer patients between 2001 and 2008, BBC reported.They were going through mammograms every 18 months to 24 months, based on Swedish standards.It is every 12 months in the US, Health Day noted.

Large Tumors Tend to Bring a Worse Prognosis

The study examined the size of the tumors at diagnosis and the body mass index of the women which is a measure of obesity.Fredrik Strand, the lead author of the study, explained the tendency of overweight women to have larger tumors – more than two centimeters -- in their bigger mammary glands which made the tumor more difficult to locate.He also did not discount the possibility that their tumors grew at a faster rate.The two-centimeter benchmark is one of the parameters used to separate stage 1 and stage 11 breast cancers, Eureka Alert wrote.

According to the research, a woman with a BMI above 25 who has denser breast tissue was linked to higher odds of having a larger tumor when diagnosed with breast cancer during screening.The researchers linked only BMI with having a large tumor for interval cancers.They have a worse prognosis than thinner women with the possibility of the cancer returning, spreading, or the patient dying from cancer.

He said that based on the study, it suggested that when the doctor presented the pros and cons of breast cancer screening to the patients, their having a high BMI should be an important argument in favor of a mammogram.The research also recommended shorter time intervals between the screenings.

Annual Screening

Health Day pointed out that the study findings might be stronger had the researchers used a US population since American women tend to be heavier than Swedish women.

Women should undergo mammograms every year, Dr.Laurie Margolies, the chief of breast imaging at Mount Sinai Health System in New York, insisted.She said the research provided another piece of evidence to end the confusion over when to have a mammogram.

However, Sophia Lowes, from Cancer Research UK, said the research failed to provide sufficient proof to support its recommendation to change the frequency of breast screening.She pointed out that mammograms have advantages and harms.

Lowes said that while mammograms help detect breast cancer at an early stage, among its harms are it diagnoses some women with cancer which would never have caused them problems in their lifetime.

The study is scheduled for presentation at the yearly meeting of the Radiological Society of North America on November 29 in Chicago.

New Biomarker

Meanwhile, Medical Xpress reported that an oncologist has discovered a biomarker for breast cancer that has a poor prognosis.Thomas Bauernhofer, from the University Hospital in Graz, Austria, said that based on a five-year research effort which he did in close collaboration with the Institutes for Biophysics and Pathology, he found that a higher expression of the GIRK1 protein showed a greater relapse rate and mortality among patients with the hormone-dependent breast cancer subtype after surgery.

He explained that the GIRK1 protein is one of at least two required elements for building functional potassium ion channels in the cell membranes.These ion channels are indispensable in the brain, human heart, brain, or pancreas.It ensures that the heart beats regularly

GIRK1 in breast cancer inspired the research team to study the protein as a potential new biomarker, according to a scientific publication with a smaller number of cases.The current research initially found a large quantity of messenger RNA which is a precursor in the production of GIRK1 protein.It was detected in breast cancer cell lines and tissue.

When the correlating tissue samples and genetic profiles of breast tumors with women's survival statistics were correlated, it became possible to identify patients at special risk of breast cancer.

Bauernhofer said that breast cancer patients with an estrogen-receptive positive tumor usually respond well to anti-hormonal treatment.However, if the ER+ tumor expresses a great amount of GIRK1, these patients have a lower probability of survival, he said.He added that the ER+ tumor subtype is found in about 60 percent of all breast cancer patients.

The Graz team also proved that besides the GIRK 1 gene, there are three more genes that are very active in a tumor.Two are associated with an estrogen receptor and third one with the angiotensin II receptor.Bauernhofer attributed the higher mortality among women with an estrogen-receptor-positive tumor and high GIRK1 expression to a diminished effect of anti-hormonal therapy or an increased ability to form metastases.  

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