State of the Russian Oncology Service: esophageal cancer. Population-based study at the federal district level. Part II. Median survival, observed and relative survival of patients considering disease stage and histological structure of tumors
Esophageal cancer (EC) is the most severe pathology of malignant tumors, with the mortality rate of patients exceeding 70% in the first year of observation. Over the past 19 years, there was a slight improvement in the effectiveness of anticancer measures for this localization of tumors. In February 2019 the Population-based Cancer Registry database (PCRD) of the Northwestern Federal District of the Russian Federation (NWFD RF) was developed with more than 1 million 350 thousand observations which provides insight into the real state of the effectiveness of anti-cancer measures and directs the following development of the database. After a thorough data quality assurance, about 1 million observations were selected for analysis. From 2000 to 2018, 15760 primary EC cases were accumulated in the NWFD RF PCRD. Considering that the levels of standardized morbidity and mortality rates of the population of Russia and the Northwestern Federal District of the Russian Federation are close in terms of the level of indicators, we believe that the data obtained for the first time in Russia on the survival of EC patients in the Northwestern Federal District of the Russian Federation fully reflect the state of the effectiveness of combating EC in Russia. The purpose of the study is to carry out a set of analytical calculations of the survival rates of EC patients in the dynamics over the past 19 years according to the NWFD RF PCRD. All calculations were performed in accordance with the international requirements for such development and, first of all, according to Eurocare standards. The results of our study indicate that the EC median survival rate for both sexes has increased from five to six months. The mortality rate of patients in the first year of follow-up has decreased from 72.4 to 71.4% (both sexes), from 73.9 to 71.6% among men, from 69.3 to 65.1% among women. The five-year survival rate of EC patients in the NWFD RF had slight fluctuations, especially among the female population. Data grouped for three five-year observation cycles has shown an increase in the five-year survival rate of EC patients from 7.3 to 8.1%, and the one-year survival rate has increased over four five-year cycles from 25.3 to 30.8%. For the first time in Russia, at the population level, the effect of treating EC patients has been shown according to the fourth sign of ICD-10. The greatest treatment success has been achieved for Cervical esophagus cancer patients (C15.0) from 23.3 to 35.0% (one-year survival), Thoracic esophagus cancer patients (C15.1) from 29.6 to 35.8%. The most significant improvement has been made for Upper third of esophagus cancer patients (C15.3) - from 18.2 to 34.0%. It is important to note that over the four observation periods, the proportion of Esophagus, unspecified cancer patients (C15.9) has decreased (from 29.3 to 19.8%), which indicates a major diagnosis quality improvement.