On 2016 Nov 18, Daniel Corcos commented:

Welch et al. assume wrongly that breast cancer incidence has been stable after the advent of screening mammography, although they find 132 more cases of BC a year per 100,000 women in the period following screening implementation. To justify this strange assumption they argue: “Those who postulate such substantial increases in underlying incidence, however, must explain why the increase coincides temporally with the introduction of screening, and why the incidence of the most aggressive form of the disease — metastatic breast cancer — remains essentially unchanged”. It is perfectly possible to explain both observations by the fact that early treatment is protective against metastasis, as expected and known for a century, and by the fact that mammography screening induces breast cancer at a much higher rate and with a shorter delay than usually expected.

References

Bleicher RJ, Ruth K, Sigurdson ER, et al. Time to Surgery and Breast Cancer Survival in the United States. JAMA Oncol 2016;2:330-9. Mathews FS. The Ten-Year Survivors of Radical Mastectomy. Ann Surg 1933;98:635-43.

On 2016 Nov 18, Daniel Corcos commented:

Welch et al. assume wrongly that breast cancer incidence has been stable after the advent of screening mammography, although they find 132 more cases of BC a year per 100,000 women in the period following screening implementation. To justify this strange assumption they argue: “Those who postulate such substantial increases in underlying incidence, however, must explain why the increase coincides temporally with the introduction of screening, and why the incidence of the most aggressive form of the disease — metastatic breast cancer — remains essentially unchanged”. It is perfectly possible to explain both observations by the fact that early treatment is protective against metastasis, as expected and known for a century, and by the fact that mammography screening induces breast cancer at a much higher rate and with a shorter delay than usually expected.

References

Bleicher RJ, Ruth K, Sigurdson ER, et al. Time to Surgery and Breast Cancer Survival in the United States. JAMA Oncol 2016;2:330-9. Mathews FS. The Ten-Year Survivors of Radical Mastectomy. Ann Surg 1933;98:635-43.