Akemi T. Wijayabahu

State-Specific Incidence of Endometrial Cancer in the United States by Histologic Subtype Corrected for Hysterectomy Prevalence from 2010 to 2019

Abstract Background: Accurate reporting of state-specific endometrial cancer incidence is important for informing cancer control efforts and may lead to new hypotheses about environmental and/or geographic risk factors. Previous studies have demonstrated the importance of accounting for hysterectomy prevalence when estimating state-level endometrial cancer incidence rates as hysterectomy prevalence varies by geographic region. Methods: We used the Cancer in North America Public Use Dataset produced by the North American Association of Central Cancer Registries to identify incident endometrial cancer cases among women ≥20 years of age diagnosed from 2010 to 2019. We estimated state-specific hysterectomy-corrected, age-adjusted incidence rates overall and by histology. State-specific hysterectomy prevalence data were obtained from the Behavioral Risk Factor Surveillance System. Results: Hysterectomy prevalence was highest in Southern and Midwestern states and lowest in the Northeast. Although uncorrected endometrial cancer incidence rates were highest in the Northeast, hysterectomy-corrected rates were highest in states within the Midwest and Appalachia. Geographic patterns of the hysterectomy-corrected incidence of endometrioid cancer resembled those of endometrial cancer overall. In contrast, corrected rates of non-endometrioid cancer were highest in the South and in certain states within the Northeast and Midwest. There was no overlap in the top 10 states with the highest rates of endometrioid and non-endometrioid cancers, respectively. Conclusions: State-specific, hysterectomy-corrected incidence rates of endometrial cancer vary by histology, suggesting potential differences in behavioral, sociodemographic, and/or environmental exposures at the state level. Impact: This study presents an accurate assessment of US endometrial cancer rates and emphasizes the importance of hysterectomy correction for geographic comparisons.

Uterine cancer incidence trends and 5-year relative survival by race/ethnicity and histology among women under 50 years

Uterine cancers diagnosed before age 50 years are increasing in the U.S., but changes in clinical characteristics and survival over time across racial/ethnic groups have not been previously described. To investigate age-adjusted, hysterectomy corrected incidence rates and trends, and 5-year relative survival rates of uterine cancer in women aged <50 years, overall and stratified by race/ethnicity and histology. We included microscopically confirmed uterine cancer cases (diagnosed 2000-2019) in women aged 20 to 49 years from the Surveillance, Epidemiology, and End Results Program. Age-adjusted incidence and 5-year relative survival rates, and 95% confidence intervals were computed using Surveillance, Epidemiology, and End Results (SEER) ∗Stat and compared across time periods (2000-2009 and 2010-2019). Incidence rates were adjusted for hysterectomy prevalence using Behavioral Risk Factor Surveillance System data, and trends were computed using the Joinpoint regression program. We included 57,128 uterine cancer cases. The incidence of uterine cancer increased from 10.1 per 100,000 in 2000-2009 to 12.0 per 100,000 in 2010-2019, increasing at an annual rate of 1.7%/y for the entire period. Rising trends were more pronounced among women <40 years (3.0%/y and 3.3%/y in 20-29 and 30-39 years, respectively) than in those 40 to 49 years (1.3%/y), and among underrepresented racial/ethnic groups (Hispanic 2.8%/y, non-Hispanic-Black 2.7%, non-Hispanic-Asian/Pacific Islander 2.1%) than in non-Hispanic-White (0.9%/y). Recent (2010-2019) incidence rates were highest for endometrioid (9.6 per 100,000), followed by sarcomas (1.2), and nonendometrioid subtypes (0.9). Rates increased significantly for endometrioid subtypes at 1.9%/y from 2000 to 2019. Recent endometrioid and nonendometrioid rates were highest in non-Hispanic-Native American/Alaska Native (15.2 and 1.4 per 100,000), followed by Hispanic (10.9 and 1.0), non-Hispanic-Asian/Pacific Islander (10.2 and 0.9), non-Hispanic-White (9.4 and 0.8), and lowest in non-Hispanic-Black women (6.4 and 0.8). Sarcoma rates were highest in non-Hispanic-Black women (1.8 per 100,000). The 5-year relative survival remained unchanged over time for women with endometrioid (from 93.4% in 2000-2009 to 93.9% in 2010-2019, P≥.05) and nonendometrioid subtypes (from 73.2% to 73.2%, P≥.05) but decreased for women with sarcoma from 69.8% (2000-2009) to 66.4% (2010-2019, P<.05). Uterine cancer incidence rates in women <50 years have increased from 2000 to 2019 while survival has remained relatively unchanged. Incidence trends can be primarily attributed to increasing rates of cancers with endometrioid histology, with the greatest increases observed among non-Hispanic-Black, Hispanic, and non-Hispanic-Asian/Pacific Islander. Sarcomas, while much rarer, were the second most common type of uterine cancer among women <50 years and have poor prognosis and apparent decreasing survival over time. Rising rates of uterine cancer and the distinct epidemiologic patterns among women <50 years highlight the need for effective prevention and early detection strategies for uterine cancer in this age group.

Hypertension and Risk of Endometrial Cancer: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium (E2C2)

Abstract Background: The incidence rates of endometrial cancer are increasing, which may partly be explained by the rising prevalence of obesity, an established risk factor for endometrial cancer. Hypertension, another component of metabolic syndrome, is also increasing in prevalence, and emerging evidence suggests that it may be associated with the development of certain cancers. The role of hypertension independent of other components of metabolic syndrome in the etiology of endometrial cancer remains unclear. In this study, we evaluated hypertension as an independent risk factor for endometrial cancer and whether this association is modified by other established risk factors. Methods: We included 15,631 endometrial cancer cases and 42,239 controls matched on age, race, and study-specific factors from 29 studies in the Epidemiology of Endometrial Cancer Consortium. We used multivariable unconditional logistic regression models to estimate ORs and 95% confidence intervals (CI) to evaluate the association between hypertension and endometrial cancer and whether this association differed by study design, race/ethnicity, body mass index, diabetes status, smoking status, or reproductive factors. Results: Hypertension was associated with an increased risk of endometrial cancer (OR, 1.14; 95% CI, 1.09–1.19). There was significant heterogeneity by study design (Phet &amp;lt; 0.01), with a stronger magnitude of association observed among case–control versus cohort studies. Stronger associations were also noted for pre-/perimenopausal women and never users of postmenopausal hormone therapy. Conclusions: Hypertension is associated with endometrial cancer risk independently from known risk factors. Future research should focus on biologic mechanisms underlying this association. Impact: This study provides evidence that hypertension may be an independent risk factor for endometrial cancer.