Routine breast cancer screening has boosted survival – but overdiagnosis, too?

22 June 2017 (Last Updated June 22nd, 2017 03:30)

Since the implementation of routine mammograms, breast cancer can be detected before symptoms present.

Routine breast cancer screening has boosted survival – but overdiagnosis, too?

Since the implementation of routine mammograms, breast cancer can be detected before symptoms present. Larger malignancies have seemingly decreased as a result of early detection; however, recent studies have shown evidence of overdiagnosis as a result of routine screening and can impact both individuals and societies.

The goal of breast cancer screening is to detect small malignancies before they grow large enough to cause symptoms. A recent study from the New England Journal of Medicine  showed an increased detection of 162 small malignancies per 100,000 women since the start of routine screening; however, only 30 of those diagnosed cases were expected to progress to become a large tumor. These results suggests that the remaining 132 cases were overdiagnosed, meaning the cases detected on screening that would not lead to experiencing symptoms or early death.

Furthermore, the study shows rather than a substantial decrease in large tumors, there was a substantial increase in small tumors and women were more likely to have breast cancer overdiagnosis than tumors expected to become large.

Overdiagnosis can lead to many implications at the individual and societal level. With only a small number of tumors leading to clinical symptoms, individuals who screen positive for small malignancies will undergo many unneeded tests and therapy sessions. These tests, in combination with multiple screening procedures and diagnostics, not only induces large amounts of stress but takes away from other areas such as work, education, and social interactions, dramatically decreasing the patient’s quality of life.

At the societal level, the unneeded tests and further screening procedures lead to wasted resources in the health care system. Where money is being spent on cases that will not progress to experiencing symptoms, less money is available to spend on patients that currently have cancer, as well as other areas in the health system.

In order to make screening more effective, research has shown that the focus should be placed on gene expression rather than an anatomy-based search, only targeting the at-risk population.