Trend in relative survival in squamous cervical cancer by decade from 1983 to 2012: a period analysis

Objective: Squamous cervical cancer (SCC), the predominant histological type, represents approximately 75-80% of all cervical cancers. Although the overall incidence of cervical cancer has declined worldwide, the data describing the changes in the incidence and long-term survival in SCC remain limited.

Methods: The data were extracted from Surveillance, Epidemiology, and End Results (SEER) registries for an evaluation of the changes in the incidence and survival associated with SCC during 1983-2012. In addition, the patients with SCC were stratified by age, race, and socioeconomic status (SES). Stata 12.0 software was used to perform the Cox regression and Spearman's rank correlation analyses.

Results: The overall incidence of SCC constantly declined from 7.3 to 5.6 to 4.3 per 100,000 people; the peak age of incidence was 55-69 years in the first decade, while the 40-54 age group served as another incidence peak in the last 2 decades. Median survival increased from 189 months to 231 months in the first 2 decades and was not reached in the third decade. The 10-year relative survival rates (RSRs) changed from 63.2% to 66.5% to 62.1% across the 3 decades. Additionally, the survival gaps narrowed from 13% to 8% between Whites and Blacks and from 5.4% to 3.5% between low- and medium-poverty groups in the 3 decades.

Conclusion: This study demonstrated a declining incidence over the 3 decades with an improvement in median survival. However, the relative survival associated with SCC did not improve in the last decade. Furthermore, the survival gaps between races and various SESs significantly narrowed over the 3 decades.