Tuesday, March 17, 2009

Changing trends in breast cancer biology

According to a new research by Scottish researchers, lifestyle changes and increased awareness towards screening have resulted in a marked shift in the types of breast cancers.The results of the research show that women are likely to have hormone-dependent and slow-growing tumors, as suggested by a comparative study of tissue samples from 1980s and 1990s.The findings of the study in the British Journal of Cancerdefine reveal a significant improved survival among breast cancer patients.Breast cancer is the most common types of cancer in women, especially younger women. Every year, at least 40,000 women are diagnosed with breast cancer in the United Kingdom alone.Lifestyle changes are playing a vital role in increasing the incidence of hormone-dependent tumors in the young women. Current trends reveal an increase in the estrogen-receptor positive cancers as it has been found that these tumors respond well to show good response to hormone therapy and prevent the disease from re-occurring. Over the last decade, estrogen-receptor positive cancers showed a rise from 64.2 percent to 71.5 percent.The exposure to estrogen increases breast cancer risk. In fact, most known risk factors for breast cancer can be attributed to some form of excess estrogen exposure.Also, there has been an increase in grade one slow-growing tumors but a decline in the number of grade three fast-growing tumors, as per the findings of the study.However, there has been no significant change in the numbers of progesterone or Her-2 positive cancers, the researchers maintained.“It's plausible that lifestyle changes could be influencing the types of breast cancers that women are developing but we will need much larger studies to find out whether this trend is real,” states Dr. Alison Ross, Cancer Research UK's senior science information officer.The researchers at the Crosshouse Hospital in Aryshire pointed out that it could be quite possible that an increasing awareness towards screening was detecting more cases of estrogen-receptor positive cancers.However, the role played by changing lifestyle factors could not be ruled out. Lifestyle changes including change in hormone levels, late marriage, postponement of childbearing, late menopause resulting in obesity and use of hormone replacement therapy after menopause are well known risk factors for developing hormone-dependent tumors. “There is evidence that the percentage of all children being born to mothers aged 35 years and over is increasing in Scotland and that means BMI and prevalence of obesity are increasing,” the researchers, led by Dr Sylvia Brown at Crosshouse Hospital in Ayrshire stated. Results from the previous studies, too, have pointed towards an increase in the incidence of hormone-dependent breast cancers, as compared to the past. However, it has been unclear whether there has been an actual increase in the number of breast cancer cases, considering the fact that increased awareness might have led to detection of these types of tumors in the recent times.“And it's also not clear whether these results reflect a shift in breast cancer biology or indicate that screening is better at detecting certain cancers,” wrote Dr Alison Ross.“If the trend identified in this interesting study is confirmed and continues, it could have an impact on the way doctors apply results from breast cancer studies done decades ago to the treatments in use today,” she clarified.
By Harleen Kaur
www.themedguru.com

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