Endometrial cancer in Puerto Rico: incidence, mortality and survival (1992-2003)

Abstract

Background: Endometrial cancer is the most common gynecologic malignancy in Puerto Rico and the United States (US).

Methods: We compare the age-specific and age-adjusted incidence and mortality rates and the survival of endometrial cancer in Puerto Rico with that of non-Hispanic whites (NHW), non-Hispanic blacks (NHB) and Hispanics in the US. Data from the Puerto Rico Central Cancer Registry and the Surveillance, Epidemiology, and End Results program were analyzed from 1992-2003.

Results: Age-standardized incidence rates of endometrial cancer increased significantly (p < 0.05) in Puerto Rico (APC = 2.8%) and among NHB (APC = 1.9%) and remained constant (p > 0.05) for NHW (APC = -0.1%) and Hispanics in the US (APC = 0.4%). Mortality trends remained constant in all racial/ethnic groups (p > 0.05). For 1999-2003, women in Puerto Rico had similar incidence of endometrial cancer as Hispanics (Standardized rate ratio [SRR] = 0.94, 95% CI = 0.87-1.01), although their risk was lower than that of NHW (SRR = 0.56, 95% CI = 0.53-0.59) and NHB (SRR = 0.91, 95% CI = 0.84-0.98). Meanwhile, women in Puerto Rico had 15% higher risk of death than Hispanic women (SRR = 1.15, 95% CI = 1.03-1.30) similar risk than NHW (SRR = 0.93, 95% CI = 0.83-1.03), and lower risk than NHB (SRR = 0.51, 95% CI = 0.46-0.57). Puerto Rico (63.1%) and NHB (56.8%) had a lower 5-year survival than NHW (78.4%) and Hispanics (79.5%). An age-adjusted Cox proportional hazards model showed that compared with women in Puerto Rico, Hispanic women in the United States had 37% lower mortality risk (HR = 0.63, 95% CI = 0.56-0.71) and NHW had 53% lower mortality risk (HR = 0.47, 95% CI = 0.43-0.52) after 5 years of diagnosis; NHB women had 22% higher mortality risk than women in Puerto Rico (HR = 1.22, 95% CI = 1.09-1.36).

Conclusions: The lower burden of endometrial cancer in Puerto Rico suggests the presence of protective factors or lower exposure to risk factors in this population, although increases in incidence suggest changes in the occurrence of lifestyles and environmental risk factors. Meanwhile, the lower five-year survival from endometrial cancer among Puerto Ricans suggests a health disparity for this group in areas such as quality of care and/or differences in terms of stage at diagnosis and associated comorbidities. Assessment of disease risk factors and characteristics, and access and response to treatment is required to further understand these results.

Figure 1

Five-year observed survival of endometrial cancer by racial/ethnic group: 1992-2002. Log-rank test X² = 817.94, p < 0.0001. Age-adjusted Cox proportional Hazards model: Hispanic: HR = 0.63, 95% CI = 0.56-0.71; NHW: HR = 0.47, 95% CI = 0.43-0.52; NHB: HR = 1.22, 95% CI = 1.09-1.36; Puerto Rico: HR = 1.00 (reference).