Browsing by Author "Figueroa, J.D."
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Item Circulating tumor DNA is readily detectable among Ghanaian breast cancer patients supporting non-invasive cancer genomic studies in Africa(Springer Nature, 2021) Ahuno, S.T.; Doebley, A-L.; Ahearn, T.U.; Yarney, J.; Titiloye, N.; Hamel, N.; Adjei, E.; Clegg-Lamptey, J-N.; Edusei, L.; Awuah, B.; Song, X.; Vanderpuye, V.; Abubakar, M.; Duggan, M.; Stover, D.G.; Nyarko, K.; Bartlett, J.M.S.; Aitpillah, F.; Ansong, D.; Gardner, K.L.; Boateng, F.A.; Bowcock, A.M.; Caldas, C.; Foulkes, W.D.; Wiafe, S.; Wiafe-Addai, B.; Garcia-Closas, M.; Kwarteng, A.; Ha, G.; Figueroa, J.D.; Polak, P.; Ghana Breast Health Study TeamCirculating tumor DNA (ctDNA) sequencing studies could provide novel insights into the molecular pathology of cancer in sub- Saharan Africa. In 15 patient plasma samples collected at the time of diagnosis as part of the Ghana Breast Health Study and unselected for tumor grade and subtype, ctDNA was detected in a majority of patients based on whole- genome sequencing at high (30×) and low (0.1×) depths. Breast cancer driver copy number alterations were observed in the majority of patients.Item Reproductive factors and risk of breast cancer by tumor subtypes among Ghanaian women: A population-based case–control study(International Journal of Cancer, 2020-02-18) Clegg-Lamptey, J-N.; Figueroa, J.D.; Lynn, B.C.D.; Edusei, L.; Titiloye, N.; Adjei, E.; Yarney, J.; Wiafe-Addai, B.; Awuah, B.; Duggan, M.A.; Wiafe, S.; Nyarko, K.; Aitpillah, F.; Ansong, D.; Hewitt, S.M.; Ahearn, T.; Garcia-Closas, M.; Brinton, L.A.; Ghana Breast Health Study TeamHigher proportions of early-onset and estrogen receptor (ER) negative cancers are observed in women of African ancestry than in women of European ancestry. Differences in risk factor distributions and associations by age at diagnosis and ER status may explain this disparity. We analyzed data from 1,126 cases (aged 18–74 years) with invasive breast cancer and 2,106 controls recruited from a population-based case–control study in Ghana. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for menstrual and reproductive factors using polytomous logistic regression models adjusted for potential confounders. Among controls, medians for age at menarche, parity, age at first birth, and breastfeeding/pregnancy were 15 years, 4 births, 20 years and 18 months, respectively. For women ≥50 years, parity and extended breastfeeding were associated with decreased risks: >5 births vs. nulliparous, OR 0.40 (95% CI 0.20–0.83) and 0.71 (95% CI 0.51–0.98) for ≥19 vs. <13 breastfeeding months/pregnancy, which did not differ by ER. In contrast, for earlier onset cases (<50 years) parity was associated with increased risk for ER-negative tumors (p-heterogeneity by ER = 0.02), which was offset by extended breastfeeding. Similar associations were observed by intrinsic-like subtypes. Less consistent relationships were observed with ages at menarche and first birth. Reproductive risk factor distributions are different from European populations but exhibited etiologic heterogeneity by age at diagnosis and ER status similar to other populations. Differences in reproductive patterns and subtype heterogeneity are consistent with racial disparities in subtype distributions.Item Skin Lighteners and Hair Relaxers as Risk Factors for Breast Cancer: Results from the Ghana Breast Health Study(Carcinogenesis, 2018-01) Brinton, L.A.; Figueroa, J.D.; Ansong, D.; Nyarko, K.M.; Wiafe, S.; Yarney, J.; Biritwum, R.; Brotzman, M.; Thistle, J.E.; Adjei, E.et.al.Skin lighteners and hair relaxers, both common among women of African descent, have been suggested as possibly affecting breast cancer risk. In Accra and Kumasi, Ghana, we collected detailed information on usage patterns of both exposures among 1131 invasive breast cancer cases and 2106 population controls. Multivariate analyses estimated odds ratios (ORs) and 95% confidence intervals (CIs) after adjustment for breast cancer risk factors. Control usage was 25.8% for ever use of skin lighteners and 90.0% for use of hair relaxers for >1 year. The OR for skin lighteners was 1.10 (95% CI 0.93-1.32), with higher risks for former (1.21, 0.98-1.50) than current (0.96, 0.74-1.24) users. No significant dose-response relations were seen by duration, age at first use or frequency of use. In contrast, an OR of 1.58 (95% CI 1.15-2.18) was associated with use of hair relaxers, with higher risks for former (2.22, 1.56-3.16) than current (1.39, 1.00-1.93) users. Although numbers of burns were inconsistently related to risk, associations increased with duration of use, restricted to women who predominately used non-lye products (P for trend < 0.01). This was most pronounced among women with few children and those with smaller tumors, suggesting a possible role for other unmeasured lifestyle factors. This study does not implicate a substantial role for skin lighteners as breast cancer risk factors, but the findings regarding hair relaxers were less reassuring. The effects of skin lighteners and hair relaxers on breast cancer should continue to be monitored, especially given some biologic plausibility for their affecting risk.