mohadeseh Rahbar - cellular and mulcullar, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran
Farshid Aaliazar - cellular and mulcullar, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran

Background: Breast cancer is the most common cancer in women and is the first cause of cancer death in 40-44 year-old women, which, if diagnosed early, is one of the most potent cancers, since determining the risk factors for this cancer can be found in early diagnosis and treatment is very effective. This malignancy accounts for 33% of women s cancers, responsible for 19% of cancer-related deaths. Many previous studies have suggested that this cancer has a relationship with lactation. Diabetes is effective in the development of certain malignant diseases, but its relationship with breast cancer is still not known. Statistics and evidence suggest a steady increase in the incidence of breast cancer. Therefore, the aim of this study was to evaluate the effect of breastfeeding and diabetes on breast cancer. Methods: In this cross-sectional study, the data were obtained by examining breast cancer registration data through Shohada-e-Tajrish Hospital. This study was conducted on 1080 women with breast cancer who referred to the Cancer Research Center of Tehran University of Shahid Beheshti during the years 1994-94. Demographic data, age of breast cancer, type of tumor, stage, grade, recurrence and metastasis of patients through their records and a researcher-made questionnaire (Cronbach s Alpha = 0.91) were collected and the status of relapsing and tumor size of the axillary lymph node was studied. . Data on the expression levels of ER, PR, HER-2 P53 and Ki67 genes were also evaluated by specific techniques. Data analysis was performed using SPSS 16 software using Mann-Whitney and Chi-square tests at a significant level of P ≤ 0.05. Results: The mean age of the patients was 44.51±11.66. In 47% of patients who had at least one lactation period, no recurrence was observed and no significant correlation was found between the numbers of breastfeeding months in patients with relapse (P> 0.05). 39% of patients had at least one lactation period, but metastasis to the lymphatic axillary complex was found. There was no significant relationship between lactation and metastasis (P> 0.05). There was a good correlation between the number of lactation months and tumor size (Correlation coefficient = 0.52, P = 0.01). 53% of patients with diabetes were in stage two but there was no statistically significant relationship between diabetes and stage and grade of disease (P> 0.05). In addition, there was no statistically significant relationship between lactation and diabetes with ER, PR, HER-2 and P53 genes (P> 0.05). Conclusion: Although, in about 65% of patients, ER, PR, HER-2 was negative, but statistically there was no relationship between diabetes and lactation with the incidence of these genes. There was a good and significant correlation between the number of lactation months and tumor size. There was no significant relationship between lactation and relapse and metastasis.

Breastfeeding, Diabetes, Breast cancer, Stage