Beth Virnig, Ph.D., answers frequently asked questions about cancer screening
We hear a lot of encouragement to get screened for various cancers. Why should we bother?
Cancer screening is based on a simple idea: cancers detected earlier are easier to treat than cancers caught later. If you find cancer when it’s small, you have many more treatment options, and the morbidity rates, both from the disease and the treatments, are lower.
How much can we depend on screening to tell us what’s going on?
A screen isn’t a diagnosis. It finds someone at higher risk for cancer and suggests there’s a need for further workup. No screening test is capable of detecting 100 percent of cancers and occasionally may offer a false negative result. Even if your screening result was normal, you should consult a doctor if you discover a lump in your breast, for example. The other imperfection is a false positive, when a screen says there’s something suspicious that needs further tests, but it turns out not to be cancer at all. There’s a gray area between normal cells and cancer cells, and that intermediary stage can be difficult to detect and categorize from images alone.
Many people have raised concerns about radiation exposure through breast cancer screening. Are there downsides to screening?
Being cautious is a good thing, and it’s important that people ask those kinds of questions. But the amount of radiation in mammograms is very low, much lower than for an X-ray. And the trials all show that the benefits of screening far outweigh any risks.
So we can expect cancer screening to remain part of routine health care?
There’s no doubt about the value of screening. For most cancers, an increase in screening results in fewer cancer deaths.