Estimation of lead time and overdiagnosis in breast cancer screening
2009

Lead Time and Overdiagnosis in Breast Cancer Screening

publication Evidence: moderate

Author Information

Author(s): Gøtzsche P C, Jørgensen K J, Mæhlen J, Zahl P-H

Primary Institution: Norwegian Institute of Public Health

Hypothesis

What is the impact of lead time adjustments on the estimation of overdiagnosis in breast cancer screening?

Conclusion

The study suggests that the overdiagnosis rate in organized mammography screening is likely around 51%, indicating significant harm to women from screening.

Supporting Evidence

  • After adjusting for lead time and other factors, the study found a 36% overdiagnosis of invasive breast cancer.
  • The authors argue that many detected cancers would not have caused problems if not for screening.
  • Previous estimates of overdiagnosis were likely too low due to flawed models.

Takeaway

When women get screened for breast cancer, some cancers that are found might not have caused any problems, and this study says that about one in three detected cancers might be overdiagnosed.

Methodology

The authors conducted a systematic review of incidence trends in countries with organized mammography screening.

Potential Biases

There may be biases in the estimates due to variations in screening practices and the definition of overdiagnosis.

Limitations

The study relies on data from various countries, which may have different screening practices and population characteristics.

Participant Demographics

Data included information from countries like the United Kingdom, Canada, Australia, Sweden, and Norway.

Digital Object Identifier (DOI)

10.1038/sj.bjc.6604762

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