Reproductive risk factors in breast cancer and genetic hormonal pathways: a gene-environment interaction in the MCC-Spain project Dierssen-Sotos, Trinidad Palazuelos-Calderón, Camilo Jiménez Moleón, José Juan Aragonés, Nuria Altzibar, Jone M. Castaño-Vinyals, Gemma Martín-Sanchez, Vicente Gómez-Acebo, Inés Guevara, Marcela Tardón, Adonina Pérez-Gómez, Beatriz Amiano, Pilar Moreno, Victor Molina, Antonio J. Alonso-Molero, Jéssica Moreno-Iribas, Conchi Kogevinas, Manolis Pollán, Marina Llorca, Javier Breast cancer Genetic interactions Reproductive factors Samples: Biological samples were stored at the biobanks supported by Instituto de Salud Carlos III- FEDER: Parc de Salut MAR Biobank (MARBiobanc) (RD09/0076/00036), “Biobanco La Fe” (RD 09 0076/00021) and FISABIO Biobank (RD09 0076/00058), and also at the Public Health Laboratory from Gipuzkoa, the Basque Biobank, the ICOBIOBANC (sponsored by the Catalan Institute of Oncology), the IUOPA Biobank from the University of Oviedo and the ISCIII Biobank. Genotyping: SNP genotyping services were provided by the Spanish “Centro Nacional de Genotipado” (CEGEN-ISCIII)”. Background: Reproductive factors are well known risk factors for breast cancer; however, little is known about how genetic variants in hormonal pathways interact with that relationship. Methods: One thousand one hundred thirty nine cases of breast cancer in women and 1322 frequency-matched controls were compared. Genetic variants in hormonal pathways (identified in the Kyoto Encyclopedia of Genes and Genomes) were screened according to their relationship with breast cancer using the Cochran-Armitage statistic. Information on reproductive factors was obtained using a face-to-face questionnaire. The interaction among the selected genetic variants and reproductive factors was tested with logistic regression. Results: Concerning C allele in rs2229712, compared to nulliparity in non-carriers the ORs for 1–2 and > 2 deliveries were 0.48 (0.28–0.81) and 0.34 (0.19–0.59), and in C carriers they were 0.92 (0.42–1.98) and 0.71 (0.31–1.61). Similar results were found in women carrying the C allele in rs1269851. Carriers of Allele T in rs35652107 and allele C in rs6018027 had the delivery number effect more pronounced. Conclusions: The number of deliveries had a dose-response protective effect on breast cancer; women carrying C allele in rs2229712 did not benefit from this protective effect. 2018-06-05T09:41:15Z 2018-06-05T09:41:15Z 2018-03-12 info:eu-repo/semantics/article Dierssen-Sotos, Trinidad; et al. Reproductive risk factors in breast cancer and genetic hormonal pathways: a gene-environment interaction in the MCC-Spain project. BMC Cancer (2018) 18:280 [http://hdl.handle.net/10481/51253] http://hdl.handle.net/10481/51253 10.1186/s12885-018-4182-3 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España BioMed Central