Cancer experts concerned over drop in mammogram rates

January 03, 2016

Mammograms are a major part of the screening process for breast cancer and current guidelines suggest all women over 40 should be screened regularly.

According to a new study the percentage of women 40 and older saying they had a mammogram within the past two years slipped from 70 percent in 2000 to 66 percent in 2005.

The mammography rate for women past the age of 40 was only 39 percent in 1987.

The study reveals a trend that experts fear may indicate a reversal of progress against the killer disease.

The researchers at the National Cancer Institute say the findings follow previous indications from various parts of the country that the popularity of mammograms was ebbing.

Dr. Nancy Breen who led the study says the results are unusual and disconcerting and come as a surprise because there is no apparent reason for the drop.

Other experts offer a number of possible reasons, including the closure of roughly 10 percent of mammography centers over insurance issues and recent doubts cast on the benefits of mammograms and also the discomfort women experience during a mammogram, as well as a rise in lawsuits.

However the results are puzzling as so much research has shown that the widespread use of mammograms have made early detection of breast cancer more common and reduced death rates from the disease.

The study found declines among groups who traditionally have used mammography at high rates, including higher-income and better-educated women, those in ages 50 to 64 and non-Hispanic whites.

Dr. Breen says the findings were based on a scientific survey of about 10,000 U.S. women 40 and older by the Centers for Disease Control and Prevention.

Cancer charities say the trend could lead to more breast cancer deaths.

Breast cancer is the second leading cause of cancer death in women and in the United States, an estimated 178,000 women will be diagnosed with breast cancer this year and about 40,000 will die from it.

The study appears in the June issue of the journal Cancer.

"Eight significant associations were found between compartment-specific, chromosome-specific loss of heterozygosity [having dissimilar pairs of genes for any hereditary characteristic]/allelic [one of two or more alternative forms of a gene] imbalance [LOH/AI], and clinicopathological features. Although only two markers on chromosome 14 in the epithelium were significantly associated with any clinicopathological feature at all (in this case, progesterone receptor), genomic instability within 7 chromosomes in the stroma of primary invasive breast carcinomas were significantly associated with tumor grade (chromosome 11) and the presence of regional lymph node metastases (chromosomes 1, 2, 5, 18, 20, and 22)," the authors write.

"These results support a model in which genetic changes in both stromal and epithelial compartments occur during tumorigenesis, and progression is codetermined by local interaction between these cell populations within the primary tumor," they write. " as with any patient-oriented study, our data should be validated, perhaps with emerging novel technologies, in larger series especially those with event-free survival data and therapeutic trials with longer follow-up."