title: Increased Incidence of Breast Cancer in Postmenopausal Women with High Body Mass Index at the Modena Screening Program.
abstract: OBJECTIVE
  We conducted a study to evaluate the relationship between body mass index (BMI) and the risk of breast cancer (BC) and outcome in a population of 14,684 women aged 55 to 69 years eligible to participate in the Mammography Screening Program (MSP) in the Province of Modena, Italy.
  
  
  METHODS
  The study population was drawn from women who underwent mammography screening between 2004 and 2006 in the Province of Modena. Women were subdivided into obese, overweight, and normal-weight categories according to BMI and followed until July 31, 2010, to evaluate the BC incidence. The clinicopathological characteristics of BC were also evaluated in different groups of patients classified according to BMI. After BC diagnosis, patients were followed for a median period of 65 (range, 2-104) months. Second events (recurrences and second tumors) were recorded, and the 5-year event-free survival (EFS) was calculated.
  
  
  RESULTS
  After a period of 73 months, 366 cases of BC were diagnosed. Compared with normal-weight women, obese women had a significantly higher incidence of BC (relative risk [RR], 1.32;p=0.040) (RR=1), larger tumors (27% of tumors were larger than T2 size), and more nodal involvement (38.5% of tumors were node-positive). Furthermore, a significantly higher rate of total events was seen in obese women compared with overweight and normal-weight patients, respectively (17.9% vs. 11.4% vs. 10.8%,p=0.032). The 5-year EFS was 89.0%, 89.0%, and 80.0% for normal-weight, overweight, and obese patients, respectively.
  
  
  CONCLUSIONS
  We observed a significantly higher risk of BC in obese women among those eligible to participate in the MSP in the Province of Modena. Finally, obese women had more second events and poorer EFS compared to nono bese women.
authors.affiliation: Department of Diagnostic and Clinical Medicine and Public Health, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Sebastiani
authors.affiliation: Department of Oncology, Hematology, and Respiratory Diseases, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Cortesi
authors.affiliation: Department of Preventive and Predictive Medicine, National Tumor Institute, Milan, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Sant
authors.affiliation: Department of Oncology, Hematology, and Respiratory Diseases, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Lucarini
authors.affiliation: Department of Oncology, Hematology, and Respiratory Diseases, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cirilli
authors.affiliation: Department of Oncology, Hematology, and Respiratory Diseases, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: De Matteis
authors.affiliation: Department of Oncology, Hematology, and Respiratory Diseases, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Marchi
authors.affiliation: Department of Radiology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Negri
authors.affiliation: Department of Radiology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Ennio
authors.initials: E
authors.lastname: Gallo
authors.affiliation: Department of Diagnostic and Clinical Medicine and Public Health, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Federico
keywords: Body mass index; Breast neoplasms; Mammography; Mass screening; Outcome assessment