ABSTRACT

DESCRIPTIVE EPIDEMIOLOGY OF ADULT LIPOSARCOMA: A POPULATION-BASED STUDY USING SEER AND THE COMBINED SEER/NPCR DATABASES,

2001-2016

SUZANNE BOCK

November 12, 2019

INTRODUCTION:

Rare cancers, affecting 1 in 5 cancer patients, disproportionally contribute to cancer mortality. This research focused on liposarcoma, an understudied rare cancer with unknown risk factors and limited treatment options.

METHODS:

Liposarcoma incident cases were identified from the Surveillance, Epidemiology, and End Result (SEER) program and the combined SEER-National Program of Cancer Registries (CNPCR) for 2001-2016. Incidence rates (age-adjusted and age-specific) and 5-year survival were calculated using SEER*stat. Time trends were determined using Joinpoint.

RESULTS:

SEER liposarcoma cases represented ~30% (n=11,162) of the nationwide pool (n=37,499). Males accounted for ~60% of the cases, 82% cases were identified among whites. Age-adjusted incidence was greater among males vs. females and whites vs. blacks, whereas survival did not differ by sex and race (~80%). The dedifferentiated (57.2%), pleomorphic (64.1%) and retroperitoneal (63.9%) tumors had the worse survival. Liposarcoma rates increased nationwide by 19% in 2001-2016, with the annual percent increase (APC) of 1.43% (95% CI: 1.12-1.47). The APC was greater for males vs. females (1.67% vs. 0.89%) and retroperitoneal vs. extremity tumors (1.96% vs. 0.58%). The SEER generally overestimated the rates and time trends compared to nationwide data.

CONCLUSIONS:

The comprehensive description of liposarcoma epidemiology reveals increasing incidence of this understudied rare cancer, with greater increases among males, the high-risk subgroup and retroperitoneal tumors, the low-survival subgroup. The time trends suggest an environmental component, which if discovered, may help to prevent liposarcoma. Differences between SEER and CNPCR findings emphasize the need for nationwide cancer surveillance.