But early stage cancer doesn’t always produce symptoms. There are screening tests for some types of cancer, but not for most.

Scientists at Johns Hopkins Sidney Kimmel Comprehensive Cancer Center are trying to change that. The researchers have developed a blood test that may be a stepping-stone to earlier diagnosis. There’s already some controversy over whether doctors are over-treating cancers that would never become a problem, such as slow-growing forms of breast and prostate cancer.

Wagman said it’s an issue that should be considered.

“It may be that many people get small cancers that go away without treatment. We’ve never been able to study this because we don’t see them when they’re that small. What if a blood test indicated breast cancer, but it’s so small that we couldn’t find it on mammogram, MRI, or PET scan? What would we do with that information? We could be finding things too soon,” he said.

He suggested that the focus should be on high-risk groups, such as those with a genetic risk — BRCA gene mutation carriers, for example, coupled with a disease that has a poor outcome. The researchers included smokers as a group who would benefit from earlier detection.

Read the source article at healthline