Improved survival in ovarian cancer, with widening survival gaps of races and socioeconomic status: a period analysis, 1983-2012

Abstract

Introduction: Ovarian cancer is the first leading cause of cancer-related deaths among gynecologic malignancies, and the 7th most common female cancer worldwide. However, previous studies on changes in the long-term survival of ovarian cancer were limited. Methods: Our data were extracted from Surveillance, Epidemiology, and End Results (SEER) registries to assess the incidence and relative survival changes of patients with ovarian cancer during 1983-2012. Patients with ovarian cancer were stratified by age, race, and socioeconomic status (SES). Cox regression analysis and Spearman rank correlation analysis were performed by STATA 12 software. Results: The overall incidence of ovarian cancer per 100,000 decreased from 13.7 to 12.4 to 10.8 over three decades with peak incidence occurring in the 70+ age group at 47.6, 45.7 and 40.2 in each respective decade. Median survival improved from 34 months to 46 months to 52 months over three decades, with the 5-year relative survival rate (RSR) increasing from 39.3% to 43.4% to 45.4% (p < 0.0001). However, Whites showed higher median survival (34 months) than Blacks (27 months) in the first decade, and the survival difference significantly increased to 16 months in the third decade. Additionally, the median survival difference between the low-poverty group and high poverty group increased from 4 months to 12 months in the three decades. Discussion: This study demonstrated the decreasing incidence of ovarian cancer with an observed improvement in relative survival over three decades in a large sample. However, the survival gaps among races and SESs significantly widened over the three decades.

Keywords: Incidence; Ovarian cancer; Period analysis; Race; Relative survival; Socioeconomic status.

Figure 1

Summary incidences of patients diagnosed with ovarian cancer between 1983 and 2012 at the original nine SEER sites. Incidence (a), and number (b) of ovarian cancer cases are shown by age group (total and ages 0-19, 20-39, 40-54, 55-69, and 70+ years) and calendar period. Incidence (c,e) and number (d,f) of ovarian cancer cases are grouped by SES and race, respectively.

Figure 2

Trends in 10-year relative survival rates (a) and Kaplan-Meier survival analysis (b) for patients with ovarian cancer at 18 SEER sites in 1983-1992 (orange), 1993-2002 (blue) and 2003-2012 (black) according to age group (total and ages 0-19, 20-39, 40-54, 55-69, and 70+ years) and calendar period.

Figure 3

1-year, 5-year and 10-year relative survival rates according to race (a) including White (orange), Black (blue) and Others (black), and SES/county-level poverty rates (b), including Low-poverty (orange), Medium-poverty (blue) and High-poverty (black) for patients with ovarian cancer at 18 SEER sites from 1983 to 2012.

Figure 4

Kaplan-Meier survival analysis according to race (a) including White (orange), and Black (blue), and SES/ county-level poverty rates (b) including Low-poverty (orange), Medium-poverty (blue) and High-poverty (black) for patients with ovarian cancer at 18 SEER sites from 1983 to 2012.