Assessment of long‐term survival of cancer patients using cancer registry data from eastern China: Period analysis is superior to traditional methods

Abstract

We aimed to provide a systematical evaluation of the performance of period analysis compared to traditional cohort and complete methods, using cancer registry data from Taizhou, eastern China. Overall, 5‐year relative survival (RS) estimate was calculated using cohort analysis, complete analysis and period analysis, respectively; further analyses were stratified by sex, region, age at diagnosis and cancer sites. Deviation value (DV), defined as the deviation between the estimated 5‐year RS obtained from each method and the observed actual survival, was calculated to evaluate the accuracy of each method. Overall, 5‐year RS derived by period analysis were much closer to the observed actual survival (51.4%), compared to those by complete and cohort methods, with the estimates of 48.7% (DV: −2.7%), 43.2% (DV: −8.2%) and 36.3% (DV: −15.1%), respectively. Further stratifications by sex, age at diagnosis, region and cancer sites also supported period analysis provided more precise estimates, compared to complete and cohort methods. We found, for first time systematically using cancer registry data from eastern China, period analysis provided more up‐to‐date precise estimates of long‐term survival for overall and stratifications by sex, age at diagnosis, region and cancer sites, compared to traditional cohort and complete methods. Nevertheless, further investigations using large cancer registry data across China are warranted for the widespread use of period analysis in China.

Using Population-Based Cancer Registration Data and Period Analysis to Accurately Assess and Predict 5-Year Relative Survival for Lung Cancer Patients in Eastern China

“…In addition to the reasons mentioned above, the trend of increasing survival in the near future for lung cancer is related to the well-educated population in Taizhou City who are more relatively aware of the importance of being physically fit than other regions ( 21 ). Moreover, Taizhou City located in eastern China, which has fast-growing economy and perfect medical insurance system ( 4 ).…”

“…The 5-year RS of lung cancer patients was calculated, which is defined as the ratio of observed survival in the patient group divided by the expected survival of a comparable group from general population ( 4 ). The expected survival was derived from life-table for the four cities of Taizhou (Luqiao, Yuhuan, Xianju and Wenling) population stratified by age, region, and calendar year, using the Ederer II method ( 10 ).…”

“…Among this formula, represented observed survival, and represented the expected survival. The point estimates of RS and their standard errors (SE) were calculated using the Greenwood method ( 4 ).…”

“…The relative survival (RS) is a key indicator of long-term survival, which reflects the level of cancer prevention and prognosis in a certain area ( 4 , 5 ). There are some methods to calculate 5-year RS by cohort approach, complete analysis and period analysis for cancer patients.…”

“…However, we choose period analysis and not other methods, because compared to traditional methods, the period analysis proposed by Brenner ( 6 ) is a new method and can evaluates the long-term survival more timely and accurately. It is considered as “gold standard” for the assessment of long-term survival of cancer patients using population-based cancer registry data and has been widely used in the western ( 6 , 7 ), and has recently by our group in Chinese population ( 4 ). However, the period analysis cannot reflect the latest survival for cancer patients because the collection of cancer registry data is generally delayed for 1–3 years and a tradeoff between timeliness and precision of survival estimates has to be balanced.…”