1.
Manjer, Jonas, et al.
(författare)
Breast cancer incidence in relation to smoking cessation
2000
Ingår i: Breast Cancer Research and Treatment. - 1573-7217. ; 61:2, s. 121-129
Tidskriftsartikel (refereegranskat) abstract
High plasma levels of oestrogens are associated with increased breast cancer risk. If smoking, as has been suggested, have both a tumour initiating mutagenic effect and a protective anti-oestrogenic effect, one would assume that smokers who give up smoking have the highest incidence of breast cancer. This was evaluated in the follow-up of a cohort of 10,902 women of whom 4,359 were premenopausal. Record-linkage with official cancer registries yielded 416 incident cases during an average follow-up of 13.6 years. The adjusted relative risk in all ex-smokers was 1.31 (1.02-1.69), as compared to never smokers, and in premenopausal ex-smokers it was 1.57 (1.07-2.30). Breast cancer incidence in premenopausal ex-smokers was inversely related to time since cessation, (p for trend = 0.01), and was highest among the women who had given-up smoking less than 12 months before screening: 2.76 (1.55-4.91). There was no significant association between current smoking and breast cancer risk. We conclude that incidence of breast cancer in premenopausal women who have given up smoking is higher than it is in smokers and never smokers. To what extent this may be related to endocrine effects associated with smoking cessation remains to be evaluated.
2.
Manjer, Jonas, et al.
(författare)
Intra-urban differences in breast cancer mortality: a study from the city of Malmo in Sweden
2000
Ingår i: Journal of Epidemiology and Community Health. - : BMJ. - 1470-2738 .- 0143-005X. ; 54:4, s. 279-285
Tidskriftsartikel (refereegranskat) abstract
STUDY OBJECTIVE: To assess whether in an urban population stage at breast cancer diagnosis is related to area of living and to what extent intra-urban differences in breast cancer mortality are related to incidence respectively stage at diagnosis. DESIGN: National registries were used to identify cases. Mortality in 17 residential areas was studied in relation to incidence and stage distribution using linear regression analysis. Areas with high and low breast cancer mortality, incidence and proportion of stage II+ tumours at diagnosis were also compared in terms of their sociodemographic profile. SETTING: City of Malmo in southern Sweden. PATIENTS: The 1675 incident breast cancer cases and 448 deaths that occurred in women above 45 years of age in Malmo 1986-96. MAIN RESULTS: Average annual age standardised breast cancer mortality ranged between residential areas, from 35/10(5) to 107/10(5), p = 0.04. Mortality of breast cancer was not correlated to incidence, r = 0.22, p = 0.39. The ratio of stage II+/0-I cancer incidence varied between areas from 0.45 to 1.99 and was significantly correlated to breast cancer mortality, r = 0.53, p = 0.03. Areas with high proportion of stage II+ cancers and high mortality/incidence ratio were characterised by a high proportion of residentials receiving income support, being foreigners and current smokers. CONCLUSIONS: Within this urban population there were marked differences in breast cancer mortality between residential areas. Stage at diagnosis, but not incidence, contributed to the pattern of mortality. Areas with high proportion of stage II+ tumours differed unfavourably in several sociodemographic aspects from the city average.
