In this report, we examined the relationship between mother's breastfeeding history and her risk of breast cancer, in a case-control study in Tunisia between 2006 and 2009. About 400 breast cancer cases and 400 controls were included. Cases and controls were interviewed using a standardized structured questionnaire to obtain information on breastfeeding and other risk factors. Mean duration of breastfeeding per child was significantly associated with a reduced risk of breast cancer for women who breastfed for > 24 months per child. The OR was 0.46 (95% CI, 0.28-0.76) when compared those who breastfed for < 6 months. The test for trend was significant (p = 0.01). A significantly reduced risk of breast cancer was found for those whose lifetime duration of breastfeeding was 73-108 months (OR = 0.65, 95% CI, 0.36- 1.18) and for those who breastfed for > or = 109 months (OR = 0.42, 95% CI, 0.20-0.84). Stratification by menopausal status showed a reduced risk of breast cancer associated with a longer duration of breastfeeding for both pre- and postmenopausal women. The risk reduction was more consistent for lifetime duration of breastfeeding, the test for trend being significant for both pre- (p = 0.03) and postmenopausal (p = 0.01) women. These results support an inverse association between breastfeeding and breast cancer risk.

In this study, we investigated the associations of polymorphisms in glutathione-S-transferases (GSTs) genes that are GSTM1, GSTT1, and GSTP1, with sporadic colorectal cancer (CRC). Hundred and fifty patients with CRC and 128 healthy controls were genotyped. DNA was isolated from blood samples. Polymorphisms were assessed by polymerase chain reaction-restriction fragment length polymorphism-based methods and polymerase chain reaction multiplex. Logistic regression analyses showed significant risk for CRC associated with GSTP1 homozygotes for Val-105 (OR 4.82; 95 % CI 1.97-11.80) or for individuals who possessed at least one Val-105 allele (OR 2.54; 95 % CI 1.751-3.703). There were no statistically significant differences in the frequency of GSTM1- and GSTT1-null genotypes (p > 0.05). The GSTM1-null was found in 70.47 % of all cases and 70.07 % of controls (OR 0.61; 95 % CI 0.33-1.12). The GSTT1-null genotype was found in 38.77 % of cases and 49.22 % of controls (OR 1.53; 95 % CI 0.94-2.47). No effect of any genotype for GSTM1 and GSTT1 on CRC was detected. But then an association between the polymorphism of the GSTP1 and the CRC susceptibility was detected.

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BACKGROUND AND OBJECTIVES:The number of breast cancer in women has increased dramatically in Tunisia. The cause is perceived to stem from adaptation to a westernized life style which increases body mass index (BMI). This study aimed to investigate the association between BMI and breast cancer among Tunisian women.DESIGN AND SETTING:Hospital-based case control study of breast cancer patients seen between November 2006 and April 2009 at the University College Hospital Farhat Hached in Sousse, Tunisia.PATIENTS AND METHODS:Standardized questionnaires concerning BMI and other anthropometric data were completed on 400 breast cancer cases and 400 controls. The controls were frequency-matched to the cases by age.RESULTS:BMI at diagnosis was positively correlated with the risk of breast cancer among postmenopausal women (P<.001 for trend). When compared with women with a low BMI (<19), women with a BMI of 23-27 and 27-31 had a 1.7-fold (95% CI, 1.1-2.9) and 2.1-fold (95% CI, 1.1-3.9) increased risk of breast cancer, respectively, after adjustment for non-anthropometric risk factors. BMI at diagnosis was not related to the risk of breast cancer among premenopausal women. The odds ratios for premenopausal women with a BMI of 23-27 and 27-31 were 1.5 (95% CI, 0.8-2.8) and 1.3 (95% CI, 0.4-4.5), respectively. Furthermore, present BMI was not associated with breast cancer risk in either pre- and postmenopausal women.CONCLUSIONS:Weight control in obese women may be an effective measure of breast cancer prevention in postmenopausal women.