Carcinogenesis Advance Access originally published online on August 18, 2008
Carcinogenesis 2008 29(11):2203-2209; doi:10.1093/carcin/bgn196
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Plant foods and oestrogen receptor 
- and β-defined breast cancer: observations from the Malmö Diet and Cancer cohort
Department of Clinical Sciences in Malmö
1 Center of Molecular Pathology, Department of Laboratory Medicine, Lund University, SE-205 02 Malmö, Sweden
2 Department of Clinical Sciences in Lund, Lund University, Lund, SE-22185 Sweden
* To whom correspondence should be addressed. Department of Clinical Sciences in Malmö, Research group in Nutrition Epidemiology, Lund University, Malmö University Hospital, Clinical Research Centre Entrance 72, Building 60, Floor 13, SE-205 02 Malmö, Sweden. Tel: +46 40 39 13 24; Fax: +46 40 39 13 22; Email: emily.sonestedt{at}med.lu.se
The associations between plant foods and breast cancer incidence are inconsistent. The objective of this study was to examine prospectively the association between dietary fibre, plant foods and breast cancer, especially the association between plant food intake and oestrogen receptor (ER) 
- and β-defined breast cancer. Among women without prevalent cancer from the population-based prospective Malmö Diet and Cancer cohort (n = 15 773, 46–75 years at baseline), 544 women were diagnosed with incident invasive breast cancer during a mean follow-up of 10.3 years. Information on dietary habits was collected by a modified diet history method. ER status of the tumours was determined by immunohistochemistry using tissue microarray. Cox proportional hazards regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with fibre and 11 plant food groups. High-fibre bread was significantly associated with a decreased breast cancer incidence (HR, 0.75; 95% CI, 0.57–0.98, for highest compared with lowest quintile). The other plant food groups were not significantly associated with breast cancer incidence. There was a tendency for a negative association for high-fibre bread among ER (+) breast cancer (P for trend = 0.06) and ERβ (+) breast cancer (P for trend = 0.06). Fried potatoes were statistically significantly associated with increased risk of ERβ (–) breast cancer (P = 0.01). This study suggests that different plant foods may be differently associated with breast cancer, with fibre-rich bread showing an inverse association. We did not observe strong evidence for differences in incidence according to the ER and ERβ status of breast cancer.
Abbreviations: CI, confidence interval; ER, oestrogen receptor; HR, hazard ratio; MDC, Malmö Diet and Cancer; MHT, menopausal hormone therapy
Received March 17, 2008; revised August 12, 2008; accepted August 13, 2008.