Survival changes in Patients with Synovial Sarcoma, 1983-2012

Abstract

Background: Synovial sarcoma (SyS) is a rare malignancy that typically invades the extremities and occurs predominantly in adolescents. Studies on incidence and survival in SyS that were based on a large population had not been reported yet. Methods: To evaluate changes in incidence and survival in SyS over three decades, we accessed data on SyS cases in each decade between 1983 and 2012 (1983-1992, 1993-2002, and 2003-2012) from the Surveillance, Epidemiology, and End Results (SEER) database. The survival difference between decades, age groups, sexes, race, pathologic types, sites, stages and socioeconomic status (SES) over three decades were accessed by comparing Kaplan-Meier curves. Results: We located 2,070 SyS cases in 18 SEER registry regions between 1983 and 2012. Our study demonstrated that the incidence of SyS per 1,000,000 continued to increase from 0.906 to 1.348 to 1.548 in the total population and in most age groups and that the age of incidence peak was 15-29 years in three decades. But, the survival of patients with SyS did not significantly improve throughout the three decades, with 5-year survival rates of 69.4%, 61.1% and 60.5% respectively (p > 0.05). Interestingly, the widening survival gaps among races, sexes, pathological types and various SES over time were observed, with narrowing p values. Conclusions: This study demonstrated the increasing incidence and unimproved survival rates across three decades in a large sample, indicating the urgency for further development of diagnosis, improving health care providers' awareness of SyS and lead to the development of novel treatments.

Keywords: incidence; sites and stages; survival; synovial sarcoma.

Figure 1

Summary incidences of patients diagnosed as having SyS between 1983 and 2012 at the original nine SEER sites. Incidence data were categorized by age, decade, stage, and site.

Figure 2

Kaplan-Meier survival analysis for patients with SyS at 18 SEER sites between 1983 and 2012 according to age group (total and ages 0-14, 15-29, 30-44, 45-59, and 60+ years).

Figure 3

Kaplan-Meier survival analysis for patients with SyS at 18 SEER sites between 1983 and 2012 according to sex and calendar period.

Figure 4

Kaplan-Meier survival analysis according to race and SES for patients with SyS at 18 SEER sites across three decades and in each decade.

Figure 5

Kaplan-Meier survival analysis according to stage and site for patients with SyS at 18 SEER sites across three decades and in each decade.

Figure 6

Kaplan-Meier survival analysis according to stage for patients with SyS at 18 SEER sites across three decades.

Figure 7

Kaplan-Meier survival analysis of pathological types according to calendar period (a) and pathological types (b) for patients with SyS at 18 SEER sites across three decades and in each decade.

Figure 8

Changes of the percentage of patients in age (a), stage (b), sex (c), site (d), race (e), and pathological types (f) across three decades.