As an undergraduate student at the University of California, Berkeley, in the late 1980s, I had the privilege of working in the laboratory of cancer geneticist Mary-Claire King, PhD, as she hunted down and identified mutations in the BRCA1 gene as a driving force in hereditary breast and ovarian cancer.
In those days such research involved lots and lots and lots of Southern blots (anyone remember those?), which required stacks of unfolded paper towels to blot size-separated DNA out of an agarose gel onto a membrane for analysis, and many, many reloadable boxes of fresh, sterilized pipette tips to load the DNA samples onto the gel. Although I was just the designated gel-pourer, paper-towel-unfolder and tip-box-loader, I wasn't immune to the palpable excitement in the lab as they neared their goal and published their landmark paper in Science in 1990.
Since then there have been many more advances in breast cancer screening, diagnosis and treatment that appear to be turning the tide of breast cancer deaths. But are they really helping to lower mortality at a population-wide level? A new study by researchers at Stanford and Georgetown University offers a resounding 'yes.'
Radiologist and biomedical data scientist Sylvia Plevritis, PhD, joined forces with oncologist Jeanne Mandelblatt, MD, from Georgetown University to investigate whether and how advances in breast cancer screening and treatment during the past decade have reduced breast cancer mortality rates. They published their results yesterday in the Journal of the American Medical Association.
From our release:
The researchers found that in 2012, screening and treatment together reduced breast cancer mortality by 49 percent. For all breast cancers together, 37 percent of that reduction was due to screening, and 63 percent was due to treatment.
However, when they looked at some molecular subtypes of cancer, the numbers varied. For ER-positive/ERBB2-positive cancer, the most common type and the type for which the greatest number of new targeted treatments are available, only 31 percent of the mortality decline was associated with screening, with 69 percent associated with treatment. For ER-negative/ERBB2-negative cancer, which has fewer treatment options, 48 percent of the mortality decline was associated with screening and 52 percent with treatment, similar to results from 2000.
Plevritis heads Stanford's Center for Cancer Systems Biology. She, Mandelblatt and the other co-authors of the paper are also part of the National Cancer Institute's Cancer Intervention and Surveillance Modeling Network, which uses statistical methods to model how cancer screening and interventions affect incidence and mortality at a population-wide level.
From our release:
Plevritis said the new results are useful for researchers and policymakers who must make decisions on how to prioritize new efforts to advance breast cancer treatment and screening.
'There have been many investments in screening and treatment; we want to know what impact those investments have had in reducing mortality,' she said. 'It also helps us think about the future and how to make sure technologies and drugs that are making the biggest difference are disseminated most widely.'
Previously: Linking cancer gene expression with survival rates, Stanford researchers bring "big data" into the clinic, Researchers find decline in chemotherapy rates for breast cancers and Why don't more breast cancer patients receive genetic testing or genetic counseling?
Photo by mararie