9. Mammography screening

*Mammography screening programs have been introduced in the French- and Italian cantons of Switzerland in 1999. Not so in German speaking parts. The below table depicts breast cancer mortality rates in women aged between 50 and 69 years (recommended ages for screening). The periods from 1986 to 1990 and from 2006 to 2010 represent, respectively, the periods before and after the establishment of organized screening programmes in Switzerland (from Vassilakos et al. Swiss Medical Weekly 2014.24;144:w13969).*

\
**What is your explanation for the increased incidence (occurrence) of breast cancer in French- and Italian-speaking Switzerland as compared to German-speaking Switzerland?**

In the period 1986–1990 there is only a slightly higher incidence in French- and Italian-speaking Switzerland, which might be by chance or a different risk profile in these regions, or because of a higher early de- tection rate (routine mammographies outside a standardized screening program). The major difference in incidence for the period 2006–2010 is due to the screening program which detects more cases.

*Mammography screening programs have been introduced in the French- and Italian cantons of Switzerland in 1999. Not so in German speaking parts. The below table depicts breast cancer mortality rates in women aged between 50 and 69 years (recommended ages for screening). The periods from 1986 to 1990 and from 2006 to 2010 represent, respectively, the periods before and after the establishment of organized screening programmes in Switzerland (from Vassilakos et al. Swiss Medical Weekly 2014.24;144:w13969).*

\
**The mortality in the French- and Italian-speaking regions was 80.1 per 100,000 women with an incidence of 229.1 in the period 1986–1990. After the introduction of the screening program, for the period 2006– 2010, the incidence was much higher and the mortality much lower. Can we say that 1) cancer is on the rise; but 2) treatment (and early detection) get better which results in lower mortality?**

1) Incidence might be higher because we more look for it (see question A) and also find more inconsequential cases. 2) Might be. It remains unclear how much of it is attributed to the screening program (see item D) and how much because of good treatment. Tamoxifen (and to a smaller extent Trastuzumab) therapies have certainly brought the mortality down. There is also indication that a change in cause-of- death coding has lead to lower mortality (Lutz et al. The impact of coding process on observed cancer mortality trends in Switzerland. Eur J Cancer Prev 2004).

*Mammography screening programs have been introduced in the French- and Italian cantons of Switzerland in 1999. Not so in German speaking parts. The below table depicts breast cancer mortality rates in women aged between 50 and 69 years (recommended ages for screening). The periods from 1986 to 1990 and from 2006 to 2010 represent, respectively, the periods before and after the establishment of organized screening programmes in Switzerland (from Vassilakos et al. Swiss Medical Weekly 2014.24;144:w13969).*

\
**Could the breast cancer incidence be risen in the later period 2006– 2010, because of ageing? There are more older persons now than back in the 1980ies and cancer is a disease mainly of the old.**

No. The incidence is strictly calculated relative per 100,000 women aged 50 to 69 years old.

*Mammography screening programs have been introduced in the French- and Italian cantons of Switzerland in 1999. Not so in German speaking parts. The below table depicts breast cancer mortality rates in women aged between 50 and 69 years (recommended ages for screening). The periods from 1986 to 1990 and from 2006 to 2010 represent, respectively, the periods before and after the establishment of organized screening programmes in Switzerland (from Vassilakos et al. Swiss Medical Weekly 2014.24;144:w13969).*

\
**What does a comparison of mortality between French- and Italian- speaking Switzerland versus German-speaking Switzerland over time tell us?**

\

Mortality decreased in all regions (see item B for two explanations). There was a similar decrease in the two regions and no difference in mortality between the two major regions of Switzerland despite the increased incidence of diagnosed breast cancer in the French and Italian- speaking regions. To conclude: these results question the effectiveness of the mammography screening program in parts of Switzerland.