Browsing by Author "Figueroa, J."
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Item Measured body size and serum estrogen metabolism in postmenopausal women: the Ghana Breast Health Study(Breast Cancer Research, 2022) Geczik, A.M.; Falk, R.T.; Xu, X.; Ansong, D.; Yarney, J.; Wiafe‑Addai, B.; Edusei, L.; Dedey, F.; Vanderpuye, V.; Titiloye, N.; Adjei, E.; Aitpillah, F.; Osei‑Bonsu, E.; Oppong, J.; Biritwum, R.; Nyarko, K.; Wiafe, S.; Awuah, B.; Clegg‑Lamptey, J-N.; Ahearn, T.U.; Figueroa, J.; Garcia‑Closas, M.; Brinton, L.A.; Trabert, B.Background: Several anthropometric measures have been associated with hormone-related cancers, and it has been shown that estrogen metabolism in postmenopausal women plays an important role in these relationships. However, little is known about circulating estrogen levels in African women, and the relevance to breast cancer or breast cancer risk factors. To shed further light on the relationship of anthropometric factors and estrogen levels in African women, we examined whether measured body mass index (BMI), waist-to-hip ratio (WHR), height, and self-reported body size were associated with serum estrogens/estrogen metabolites in a cross-sectional analysis among postmenopausal population-based controls of the Ghana Breast Health Study. Methods: Fifteen estrogens/estrogen metabolites were quantified using liquid chromatography-tandem mass spectrometry in serum samples collected from postmenopausal female controls enrolled in the Ghana Breast Health Study, a population-based case–control study conducted in Accra and Kumasi. Geometric means (GMs) of estrogens/ estrogen metabolites were estimated using linear regression, adjusting for potential confounders. Results: Measured BMI (≥30 vs. 18.5–24.9 kg/m2) was positively associated with parent estrogens (multivariable adjusted GM for unconjugated estrone: 78.90 (66.57–93.53) vs. 50.89 (43.47–59.59), p-value previously noted among White women suggests that estrogens likely explain part of the BMI-postmenopausal breast cancer risk in both groups. These findings merit evaluation in Black women, including prospective studies.Item Measured body size and serum estrogen metabolism in postmenopausal women: the Ghana Breast Health Study(BMC, 2022) Geczik, A.M.; Falk, R.T.; Xu, X.; Ansong, D.; Yarney, J.; Wiafe‑Addai, B.; Edusei, L.; Dedey, F.; Vanderpuye, V.; Titiloye, N.; Adjei, E.; Aitpillah, F.; Osei‑Bonsu, E.; Oppong, J.; Biritwum, R.; Nyarko, K.; Wiafe, S.; Awuah, B.; Clegg‑Lamptey, J.; Ahearn, T.U.; Figueroa, J.; Garcia‑Closas, M.; Brinton, L.A.; Trabert, B.Background: Several anthropometric measures have been associated with hormone-related cancers, and it has been shown that estrogen metabolism in postmenopausal women plays an important role in these relationships. However, little is known about circulating estrogen levels in African women, and the relevance to breast cancer or breast cancer risk factors. To shed further light on the relationship of anthropometric factors and estrogen levels in African women, we examined whether measured body mass index (BMI), waist-to-hip ratio (WHR), height, and selfreported body size were associated with serum estrogens/estrogen metabolites in a cross-sectional analysis among postmenopausal population-based controls of the Ghana Breast Health Study. Methods: Fifteen estrogens/estrogen metabolites were quantified using liquid chromatography-tandem mass spectrometry in serum samples collected from postmenopausal female controls enrolled in the Ghana Breast Health Study, a population-based case–control study conducted in Accra and Kumasi. Geometric means (GMs) of estrogens/ estrogen metabolites were estimated using linear regression, adjusting for potential confounders. Results: Measured BMI (≥ 30 vs. 18.5–24.9 kg/m2) was positively associated with parent estrogens (multivariable adjusted GM for unconjugated estrone: 78.90 (66.57–93.53) vs. 50.89 (43.47–59.59), p-value < 0.0001; and unconjugated estradiol: 27.83 (21.47–36.07) vs. 13.26 (10.37–16.95), p-value < 0.0001). Independent of unconjugated estradiol, measured BMI was associated with lower levels of 2-pathway metabolites and higher levels of 16-ketoestradriol. Similar patterns of association were found with WHR; however, the associations were not entirely independent of BMI. Height was not associated with postmenopausal estrogens/estrogen metabolite levels in African women. Conclusions: We observed strong associations between measured BMI and parent estrogens and estrogen metabolite patterns that largely mirrored relations that have previously been associated with higher breast cancer risk in postmenopausal White women. The consistency of the BMI-estrogen metabolism associations in our study with those previously noted among White women suggests that estrogens likely explain part of the BMI-postmenopausal breast cancer risk in both groups. These findings merit evaluation in Black women, including prospective studies.Item Recruiting population controls for case-control studies in sub-Saharan Africa: The Ghana Breast Health Study(PLoS ONE, 2019-04) Nyante, S.J.; Biritwum, R.; Figueroa, J.; Graubard, B.; Awuah, B.; Addai, B.W.; Yarney, J.; Clegg-Lamptey, J.N.; Ansong, D.et.al.Background In case-control studies, population controls can help ensure generalizability; however, the selection of population controls can be challenging in environments that lack population registries. We developed a population enumeration and sampling strategy to facilitate use of population controls in a breast cancer case-control study conducted in Ghana. Methods Household enumeration was conducted in 110 census-defined geographic areas within Ghana’s Ashanti, Central, Eastern, and Greater Accra Regions. A pool of potential controls (women aged 18 to 74 years, never diagnosed with breast cancer) was selected from the enumeration using systematic random sampling and frequency-matched to the anticipated distributions of age and residence among cases. Multiple attempts were made to contact potential controls to assess eligibility and arrange for study participation. To increase participation, we implemented a refusal conversion protocol in which initial non-participants were re-approached after several months. Results 2,528 women were sampled from the enumeration listing, 2,261 (89%) were successfully contacted, and 2,106 were enrolled (overall recruitment of 83%). 170 women were enrolled through refusal conversion. Compared with women enrolled after being first approached, refusal conversion enrollees were younger and less likely to complete the study interview in the study hospital (13% vs. 23%). The most common reasons for non-participation were lack of interest and lack of time. Conclusions Using household enumeration and repeated contacts, we were able to recruit population controls with a high participation rate. Our approach may provide a blue-print for others undertaking epidemiologic studies in populations that lack accessible population registries.