Abstract 1189: Association between female breast cancer period prevalence and residential exposure to environmental hazards at Hermosillo municipality, Sonora, Mexico: A retrospective observational study based on clinical databases from years 2013 to 2019 and INEGI census 2010

Background: Breast cancer is the leading cause of female cancer-related deaths in Mexico. Breast cancer risk may increase given residential exposure to environmental hazards, such as industrial-produced air pollutants (HAPs), and residual water sites (RWS). Hermosillo is one municipality with high breast cancer prevalence in Sonora, Mexico. However, the association of environmental hazards with breast cancer remains a matter of debate for this community.

Objectives: This retrospective observational study aims to evaluate associations between breast cancer period prevalence (years 2013 - 2019) and residential exposure to potentially hazardous sites (PHS) in Hermosillo.

Methods: The study collected the data from 912 female breast cancer cases from 6-year old hospital files (2013 to 2019) in Hermosillo. INEGI Census 2010 provided the PHS coordinates, and ArcGIS software (version 10.7.1) projected the data onto a map by conversion to UTM 12 N. Cluster analysis identified regions of high breast cancer period prevalence. Additionally, PHS-proximity is used as a criterion to define subpopulations of interest. The odds ratio (OR) estimated breast cancer risk among the Hermosillo subpopulations to find a difference between them. Age distribution analysis assessed putative residential exposure between PHS-exposed and non-PHS-exposed breast cancer cases.

Results: Findings indicate high-high clusters in six neighborhoods across Hermosillo, and from those, three are contiguous. Significant associations with breast cancer risk were the following: residence in highly-industrialized (≥ 7 industries) vs low-industrialized neighborhoods (≤ 6 industries) with an OR = 1.69 (1.41, 2.02) (p-value < 0.0001); residence within ≤ 4 km to gas power plants (GPP) vs those ≥ 4 km (OR = 1.55, (1.36, 1.77)) (p -value < 0.0001); residence within ≤ 3 km to RWS vs residences ≥ 3 km (OR = 1.45, (1.26, 1.66)) (p-value < 0.0001). In comparison to non-PHS-exposed locations, cumulative residential exposure to highly-industrialized neighborhoods within ≤ 4 km to GPP and RWS (PHS-exposed) had an OR = 2.29 (1.80, 2.91) (p-value < 0.0001). Moreover, older breast cancer patients (≥ 58 years old) are in PHS-exposed subpopulation.

Conclusions: This study shows a difference in breast cancer prevalence for highly industrialized neighborhoods closer to HAPs' sources (GPP) and RWS. Age distribution showed an older population in the PHS-exposed group. Further studies with larger cohorts are needed to confirm or reject these findings.

Citation Format: Diana E. Villa-Guillen, Enrique Avila-Monteverde, Jose H. Gonzalez-Zepeda, Luis F. Munguia-Ibarra, Baldemar Corral-Villegas, Karla Aguilar-Gutierrez, Cynthia Rojas-Camarena, Luis C. Durazo-Cons, Carlos D. Luque-Morales, Wendy B. Aguilar-Peraza, Jorge A. Cordon-Guillen, Leticia Garcia-Rico, Martin Jara-Marini, Ana I. Valenzuela-Quintanar, Graciela Caire-Juvera, Ivan Anduro-Corona, Eduardo Ruiz-Bustos, Jorge A. Villa-Carrillo. Association between female breast cancer period prevalence and residential exposure to environmental hazards at Hermosillo municipality, Sonora, Mexico: A retrospective observational study based on clinical databases from years 2013 to 2019 and INEGI census 2010 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1189.

Abstract P5-08-21: Breast cancer risk and residential exposure to environmental hazards in Hermosillo, Sonora, Mexico

Introduction: Breast cancer is the leading cause of female cancer-related deaths in Mexico. Residential exposure to environmental hazards, like air pollutants produced by industrial activities (HAPs), and contaminated sources of drinking water (CSW) may increase breast cancer risk. There is an interest in assessing environmental pollutants as risk factors, but there is no consensus on such an association. Hermosillo municipality is one of the regions with high breast cancer incidence at Sonora, Mexico. The role of environmental hazards on breast cancer risk in Hermosillo; however, has not been fully explored. This study aims at evaluating associations between breast cancer incidence rates and residential exposure to potentially hazardous sites (PHS). Objective: The aim is to determine breast cancer incidence rates in neighborhoods in the municipality of Hermosillo exposed to HAPs and/or CSW. Methods: Data (744 cases) is being collected from 5-year old clinical files of breast cancer patients residing in Hermosillo, and who were patients in private and public hospitals. Coordinates of PHS were obtained through government databases (INEGI, CONAGUA, SAGARPA) and projected onto a map by conversion to UTM zone 12 N. Cluster analysis was conducted to identify geographic regions of high breast cancer incidence. Neighborhoods were classified by their proximity to PHS, then calculated odds ratio (OR) and 95% confidence interval for breast cancer risk among residentially exposed inhabitants with that for non-exposed tenants. Results: Preliminary findings include high-high breast cancer clusters in five neighborhoods across Hermosillo, and from those, three are contiguous. In order to evaluate the association between neighborhoods with breast cancer cases, and the number of industries, an OR = 1.55 was obtained ((1.26 - 1.90), 95% CI, p-value = 0.00002). The previous comparison involved the location of 6 or more factories and those with less than 6 facilities (gas power industries excluded). We also examined an association between neighborhoods with breast cancer cases and their proximity (radio distance in km) to gas power industries-only. A comparison was made between neighborhoods within a radio of ≤ 2 km with those between a radio 2 - 4 km resulting in an OR = 0.68 ((0.56 - 0.83) CI, p-value = 0.00001). An additional comparison was carried out between residential locations within a radio of ≤ 2 km to those beyond 4 km, estimating an OR = 0.53 ((0.44 - 0.64), 95% CI, p-value < 0.00001). Furthermore, we evaluated associations for neighborhoods potentially exposed to CSW; particularly to residual waters within a radio of <1, between 1 - 2 km, and between 2 - 3 km. OR did not show significant differences for those comparisons. Conclusions: At this point in the study, a difference in breast cancer incidence rates has been observed in more industrialized neighborhoods or which are closer to potential sources of HAPs (gas power facilities). Residential proximity to CSW shows no association with incidence rates. Further studies with larger cohorts are needed to confirm findings.

Citation Format: Diana Evelyn Villa-Guillen, Enrique Avila-Monteverde, Jose H Gonzalez-Zepeda, Luis F Munguia-Ibarra, Baldemar Corral-Villegas, Leticia Garcia-Rico, Martin Jara-Marini, Ana I Valenzuela-Quintanar, Graciela Caire-Juvera, Ivan Anduro-Corona, Eduardo Ruiz-Bustos, Jorge A Villa-Carrillo. Breast cancer risk and residential exposure to environmental hazards in Hermosillo, Sonora, Mexico [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-08-21.