Dataset Information

The distribution of reproductive risk factors disclosed the heterogeneity of receptor-defined breast cancer subtypes among Tanzanian women.

ABSTRACT:

Background

Recent epidemiological studies suggest that reproductive factors are associated with breast cancer (BC) molecular subtypes. However, these associations have not been thoroughly studied in the African populations. The present study aimed to investigate the prevalence of BC molecular subtypes and assess their association with reproductive factors in Tanzanian BC patients.

Methods

This hospital-based case-only cross-sectional study consisted of 263 histologically confirmed BC patients in Tanzania. Clinico-pathological data, socio-demographic characteristics, anthropometric measurements, and reproductive risk factors were examined using the Chi-square test and one-way ANOVA. The association among reproductive factors and BC molecular subtypes was analyzed using multinomial logistic regression. The heterogeneity of the associations was assessed using the Wald test.

Results

We found evident subtype heterogeneity for reproductive factors. We observed that post-menopausal status was more prevalent in luminal-A subtype, while compared to luminal-A subtype, luminal-B and HER-2 enriched subtypes were less likely to be found in post-menopausal women (OR: 0.21, 95%CI 0.10-0.41, p = 0.001; OR: 0.39, 95%CI 0.17-0.89, p = 0.026, respectively). Also, the luminal-B subtype was more likely to be diagnosed in patients aged ≤ 40 years than the luminal-A subtype (OR: 2.80, 95%CI 1.46-5.32, p = 0.002). Women who had their first full-term pregnancy at < 30 years were more likely to be of luminal-B (OR: 2.71, 95%CI 1.18-4.17, p = 0.018), and triple-negative (OR: 2.28, 95%CI 1.02-4.07, p = 0.044) subtypes relative to luminal-A subtype. Furthermore, we observed that breastfeeding might have reduced odds of developing luminal-A, luminal-B and triple-negative subtypes. Women who never breastfed were more likely to be diagnosed with luminal-B and triple-negative subtypes when compared to luminal-A subtype (OR: 0.46, 95%CI 0.22-0.95, p = 0.035; OR: 0.41, 95%CI 0.20-0.85, p = 0.017, respectively). .

Conclusion

Our results are the first data reporting reproductive factors heterogeneity among BC molecular subtypes in Tanzania. Our findings suggest that breast-feeding may reduce the likelihood of developing luminal-A, luminal-B, and triple-negative subtypes. Meanwhile, the first full-term pregnancy after 30 years of age could increase the chance of developing luminal-A subtype, a highly prevalent subtype in Tanzania. More interventions to promote modifiable risk factors across multiple levels may most successfully reduce BC incidence in Africa.

SUBMITTER: Rweyemamu LP

PROVIDER: S-EPMC8686374 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BACKGROUND:Underweight, overweight, and obesity are major public health challenges among reproductive-age women of lower- and middle-income countries (including Tanzania). In those settings, obesogenic factors (attributes that promote excessive body weight gain) are increasing in the context of an existing high burden of undernutrition. The present study investigated factors associated with underweight, overweight, and obesity among reproductive age women in Tanzania. METHODS:This study used 2015-16 Tanzania Demographic and Health Survey data (n = 11735). To account for the hierarchical nature of the data (i.e., reproductive age women nested within clusters), multilevel multinomial logistic regression models were used to investigate the association between individual-level (socioeconomic, demographic and behavioural) and community-level factors with underweight, overweight, and obesity. RESULTS:Reproductive age women who were informally employed (relative risk ratio [RRR] = 0.79; 95% confidence interval [CI]: 0.64, 0.96), those who were currently married (RRR = 0.59; 95% CI: 0.43, 0.82) and those who used contraceptives (RRR = 0.70; 95% CI: 0.54, 0.90) were less likely to be underweight. Reproductive age women who attained secondary or higher education (RRR = 1.48; 95% CI: 1.11, 1.96), those who resided in wealthier households (RRR = 2.31; 95% CI: 1.78, 3.03) and those who watched the television (RRR = 1.26; 95% CI: 1.06, 1.50) were more likely to be overweight. The risk of experiencing obesity was higher among reproductive age women who attained secondary or higher education (RRR = 1.79; 95% CI: 1.23, 2.61), those who were formally employed (RRR = 1.50; 95% CI: 1.14, 1.98), those who resided in wealthier households (RRR = 4.77; 95% CI: 3.03, 7.50), those who used alcohol (RRR = 1.43; 95% CI: 1.12, 1.82) and/or watched the television (RRR = 1.70; 95% CI: 1.35, 2.13). CONCLUSION:Our study suggests that relevant government jurisdictions need to identify, promote, and implement evidence-based interventions that can simultaneously address underweight and overweight/obesity among reproductive age women in Tanzania.

Project description:Aside from age, sex, and family history, risk of developing breast cancer is largely linked to reproductive factors, which characterize exposure to sex hormones. Given that, molecular testing at the tumor level is currently possible, clinical characterization of tumor subtypes is routinely conducted to guide treatment decisions. However, despite the vast amount of published data from observational studies on reproductive factor associations and breast cancer risk, relatively fewer reports have been published on associations specific to breast tumor subtypes. We conducted a review of the literature and summarized the results of associations between reproductive factors and risk or odds of three distinct tumor subtypes: estrogen receptor/progesterone receptor positive (hormone receptor positive, HR+ tumors), tumors overexpressing the human epidermal receptor 2 protein (HER2+), and triple negative breast cancer (TNBC), which lacks the three markers. Results show that the most consistent evidence for associations with reproductive risk factors exists for HR+ breast cancers, with nulliparity, current use of menopausal hormone therapy, and prolonged interval between menarche and age at first birth being the strongest risk factors; increased age at first birth and decreased age at menarche were fairly consistently associated with HR+ cancers; and though less consistent, older age at menopause was also positively associated, while lactation was inversely associated with HR+ tumors. Fewer consistent associations have been reported for TNBC. The single protective factor most consistently associated with TNBC was longer duration of breastfeeding. Increased parity, younger age at first birth, older age at menarche, and oral contraceptive use were less consistently shown to be associated with TNBC. No remarkable associations for HER2+ breast cancers were evident, although this was based on relatively scarce data. Findings suggest heterogeneity in reproductive risk factors for the distinct subtypes of breast tumors, which may have implications for recommended prevention strategies.