The relative survival and cure fraction of gastric cancer estimated through flexible parametric models using data from population‐based cancer registration during 2003‐2012 in Linzhou, China

PURPOSE: The proportion of cured gastric cancer patients has drawn the attention of patients, physicians, and healthcare providers after comprehensive prevention and control measures were carried out for several years. Therefore, the relative survival and cure fraction were estimated in our study. METHODS: Population‐based cancer registration data were used to estimate survival and cure fraction. A total of 7585 gastric cancer cases (ICD10:C16.0 ~ C16.9) were extracted and included in the final analysis. Cases were diagnosed in 2003‐2012 and followed until the end of 2017. Relative survival was calculated as the ratio between the observed survival through the life‐table method. The expected survival was estimated by the Ederer II method. The cure fraction was estimated using flexible parametric cure models stratified by age and calendar period when the cases were diagnosed. RESULTS: The 5‐year relative survival of cardia gastric cancer increased with the calendar period of 2003‐2004, 2005‐2006, 2007‐2008, 2009‐2010, and 2011‐2012 (27.5%, 28.3%, 33.5%, 38.2%, and 46.8%, respectively). The increasing trend along with the calendar periods was also observed in cure proportion of cardia gastric cancer (24.8%, 25.2%, 31.7%, 36.0%, and 43.1%, respectively). Notable improvement of cure proportion was observed in the period of 2011‐2012, compared with the initial period of 2003‐2004. There was an improvement of 79.8% among all gastric cancer subjects, and it was 74.1% and 55.7% in cardia gastric and noncardia gastric cancer subjects, respectively. The median survival of “uncured” patients showed no significant improvement along with the calendar periods in all age groups. CONCLUSIONS: Notable improvement of gastric cancer relative survival and cure proportion was observed in Linzhou during 2003‐2012.