Impact of a programme of mass mammography screening for breast cancer on socio-economic variation in survival: a population-based study.
BACKGROUND
After a systematic mass mammography breast cancer screening programme was implemented between 1991 and 1996 (attendance 80%), we evaluated its impact on survival according to socioeconomic status (SES).


METHODS
We studied survival rates up to 1-1-2005 for all consecutive breast cancer patients aged 50-69 and diagnosed in the period 1983-2002 in the area of the Eindhoven Cancer Registry (n = 4939). Multivariate analyses were performed using Cox regression analysis.


RESULTS
The proportion of breast cancer patients with a low SES decreased from 22% in 1983-1990 to 14% in 1997-2002 when attendance was 85%. The proportion of newly diagnosed patients with stage III or IV disease in 1997-2002 was only 10% compared to 14% in 1991-1996 and 26% in 1983-1989 (P < 0.0001). Stage distribution improved for all socio-economic groups (P = 0.01). Survival was similar for all socio-economic groups in 1983-1990, but after the introduction of the screening programme women with low SES had lower age- and stage-adjusted survival rates (HR 2.0, 95%CI: 1.3-3.0). Survival was better for patients diagnosed in 1997-2002 compared to 1983-1990 for all socioeconomic strata; it was substantially better for the high SES group (HR 0.36, 0.2-0.5) compared to the lowest SES (HR 0.77, 0.6-1.1).


CONCLUSIONS
Although survival improved for women from each of the socio-economic strata, related to the high participation rate of the screening programme, women from lower socio-economic strata clearly benefited less from the breast cancer screening programme. That is also related to the higher prevalence of comorbidity and possibly suboptimal treatment.
Louwman
W J
WJ
Eindhoven Cancer Registry, Comprehensive Cancer Centre South (IKZ), Eindhoven, P.O. Box 231, 5600 AE, Eindhoven, The Netherlands. research@ikz.nl.
van de Poll-Franse
L V
LV
Fracheboud
J
J
Roukema
J A
JA
Coebergh
J W W
JW
D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000191:economics* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008327:Mammography / Q000191:economics*; D008403:Mass Screening / Q000191:economics*; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D012044:Regression Analysis; D012962:Sociology, Medical; D015996:Survival Rate; D013997:Time Factors