Geographic trends in rare uterine sarcomas: could environment affect incidence? (403)

Abstract

Objectives: To expand on recently published data by evaluating geographic trends in uterine sarcoma incidence in US women. Methods: Data were obtained from the United States Cancer Statistics (USCS) database from 2001 to 2017. Cancer incidences were described using SEER*Stata 8.3.8. The average annual percent change (AAPC) was calculated using Joinpoint regression. Reported demographic factors included age, race, and geographic region. Results: Using USCS data, we examined geographic trends in the incidence of rare uterine cancers with sarcoma histology. Over this time period, 778,891 cases of uterine cancer were diagnosed; 2.0% were leiomyosarcomas, 1.1% endometrial stromal sarcomas, and 0.5% adenosarcomas. In the most recent year, leiomyosarcoma was the most commonly diagnosed sarcoma, reaching an age-adjusted incidence of 0.53 per 100,000 compared to only 0.27 per 100,000 in endometrial stromal carcinoma and 0.14 per 100,000 in adenosar- coma. Based on geographic region, those residing in the Northeast had the highest incidence of leiomyosarcoma at 0.59 per 100,00, while women in the South had the most rapid increase in incidence at 0.80% annually (p=0.003). However, intersectional analysis of race and region showed that the incidence among Black women in the South was 1.11 per 100,000, more than two-fold higher than the incidence in the general population. This group also had an average annual increase of 2.58% (p<0.001), more than five times faster than the increase seen in the general population. Similar to leiomyosarcomas, endometrial stromal sarcomas had the highest incidence in the Northeast at 0.32 per 100,000. The annual change was also greatest in the Northeast at -1.91% per year (p=0.001). Conversely, adenosar- comas had the highest incidence in the Midwest (0.16 per 100,000) and the most rapid increase in the West (2.22% per year, p=0.006). Conclusions: Incidence of uterine sarcomas varies by geographic region, and intersectional analysis by race and region emphasizes the importance of considering multiple factors in analyzing incidence trends. Further studies are warranted to describe the environmental and socio-behavioral determinants associated with geographic disparities in uterine sarcomas. Objectives: To expand on recently published data by evaluating geographic trends in uterine sarcoma incidence in US women. Methods: Data were obtained from the United States Cancer Statistics (USCS) database from 2001 to 2017. Cancer incidences were described using SEER*Stata 8.3.8. The average annual percent change (AAPC) was calculated using Joinpoint regression. Reported demographic factors included age, race, and geographic region. Results: Using USCS data, we examined geographic trends in the incidence of rare uterine cancers with sarcoma histology. Over this time period, 778,891 cases of uterine cancer were diagnosed; 2.0% were leiomyosarcomas, 1.1% endometrial stromal sarcomas, and 0.5% adenosarcomas. In the most recent year, leiomyosarcoma was the most commonly diagnosed sarcoma, reaching an age-adjusted incidence of 0.53 per 100,000 compared to only 0.27 per 100,000 in endometrial stromal carcinoma and 0.14 per 100,000 in adenosar- coma. Based on geographic region, those residing in the Northeast had the highest incidence of leiomyosarcoma at 0.59 per 100,00, while women in the South had the most rapid increase in incidence at 0.80% annually (p=0.003). However, intersectional analysis of race and region showed that the incidence among Black women in the South was 1.11 per 100,000, more than two-fold higher than the incidence in the general population. This group also had an average annual increase of 2.58% (p<0.001), more than five times faster than the increase seen in the general population. Similar to leiomyosarcomas, endometrial stromal sarcomas had the highest incidence in the Northeast at 0.32 per 100,000. The annual change was also greatest in the Northeast at -1.91% per year (p=0.001). Conversely, adenosar- comas had the highest incidence in the Midwest (0.16 per 100,000) and the most rapid increase in the West (2.22% per year, p=0.006). Conclusions: Incidence of uterine sarcomas varies by geographic region, and intersectional analysis by race and region emphasizes the importance of considering multiple factors in analyzing incidence trends. Further studies are warranted to describe the environmental and socio-behavioral determinants associated with geographic disparities in uterine sarcomas.