ASPO Abstracts
Incidence of second primary cancer among survivors of gynecologic cancers in the United States: A population-based study
Category: Survivorship & Health Outcomes/Comparative Effectiveness Research
Conference Year: 2020
Abstract Body:
Introduction: With advances in treatment technology, the population of gynecologic
cancer (GC) cancer survivors is rapidly growing and are at risk for developing second
primary cancers (SPCs). SPCs are the leading causes of morbidity and mortality among
GCs survivors. Identifying and targeting at-risk sites through cancer screening and s
surveillance may help to guide best practices. We examined the incidence of SPCs a
among survivors of GCs and to identify anatomic sites at elevated risks of SPCs.
Methods: Using the Surveillance, Epidemiology and End Results (SEER) cancer
registries, we identified survivors of GCs (cervical, endometrial, ovary, vaginal, and
vulva) between 2000 and 2016. SPC was defined as the first subsequent primary cancer
occurring at least 2 months after first cancer diagnosis. SPC risk was quantified by
calculating standard incidence ratios (SIRs -- defined as observed to expected cases)
and excess absolute risks (EARs -- defined as observed - expected cases) per 10 000
person-years at risk (PYR). SIRs and EARs were calculated for all subsequent cancers s
stratified by each index cancer site and latency interval.
Results: Of 301,210 patients with GCs, 19,005 (6.31%) developed a SPC, which
corresponded to an overall SIR of 1.16 (95% CI, 1.15-1.18) and EAR of 17.2 cases per
10,000 PYR compared to that of the general population. All index cancer sites (except
ovary) were associated with a significant increase in SPC risk (the SIR ranged from 1.06
to 2.16) with greatest risk among survivors of vulvar cancer (SIR=2.16; 95% CI,
2.06-2.27; EAR=139.5 per 10,000 PYR). Secondary vaginal cancer was the most
common SPC among survivors of index cervical, endometrial, ovary, and vulvar. For
survivors of index cervical and vulvar cancers, the majority of the second cancers
survivors developed were tobacco-related such as lung and bronchus, bladder, and oral c
cavity. The increased risk of SPC among survivors was greatest in the first 5 years f
following initial diagnosis for cancers except ovary.
Conclusions: Survivors of GCs are at an increased risk of subsequent SPCs compared to
the general population, particularly in those diagnosed with index vulva cancers. These
findings have the potential to inform surveillance recommendations for survivors of GCs.
Keywords: Gynecologic cancer; second cancers; cancer survivors; surveillance surveillance