A population-based study of soft tissue sarcoma incidence and survival in Australia: An analysis of 26,970 cases

Soft tissue sarcomas (STS) are rare, often fatal tumors, but little is known of the epidemiology and survival in the Australian population. This study aims to provide the first epidemiological analysis of incidence and survival rates of STS in the Australian population.

A retrospective population-based observational study was conducted between 1982 and 2009 of all patients with a diagnosis of STS using the Australian Institute of Health and Welfare (AIHW) Australian Cancer Database. Incidence rates per 100,000; incidence rate ratios, age-standardized incidence rates, prevalence and incidence rates of subtypes of STS, median, one-year and 5-year survival rates were examined.

A total of 26,970 patients were identified. Between 1982 and 2009 STS incidence rates significantly increased from 3.99 [95% CI 3.68-4.32] to 6.12 [95% CI 5.80-6.46] per 100,000 Australian population, with a peak incident rate ratio (IRR) of 1.59 [95% CI 1.51-1.69] (p < 0.0001) in 2001. Median age at diagnosis increased from 58 to 63 years. Incidence rates were stable across all 10-year age cohorts, except for people aged over 70 where it increased. Overall, age-standardized incidence rates increased from 4.70 [95% CI 4.42-5.00] in 1982 to 5.87 [95% CI 5.63-6.11] per 100 000 Australians in 2009. Leiomyosarcoma (20.43%), malignant fibrous histiocytoma (16.14%), and soft tissue tumors/sarcomas, not otherwise specified (10.18%) were the most common STS subtypes. Median survival from diagnosis increased from 5.80 years [95% CI 5.06-6.54] in 1985-1989 cohort to 8.18 years [95% CI 7.54-8.81] in the 2000-2004 cohort (log-rank test p < 0.0001).

The incidence of STS is increasing in Australia, most noticeably in those aged over 70 years, with a small but statistically significant increase in overall survival rates.