The state of cancer care for gastric cancer (C16) in Russia: a population-based analysis of survival and treatment effectiveness considering age and sex characteristics. Part 2 (clinical-population study)
The study is devoted to analyzing the dynamics of one-year and five-year survival rates of gastric cancer (GC) patients in the Northwestern Federal District of Russia (NWFD RF) at the population level, taking into account age and sex characteristics, as well as comparing real survival rates with official statistics data. The study used the database of the Population-Based Cancer Registry (PBCR) of the NWFD RF, containing 88,572 verified cases of GC for the period 2000–2022. Observed and relative survival were calculated using a modified Eurocare program. It was found that one-year observed survival of GC patients increased from 37.4% (2000–2004) to 45.8% (2020–2022), an increase of 22.5%. This indicator is higher in women (47.5%) than in men (44.5%). Five-year observed survival (calculated up to 2014) increased from 17.0% to 19.1%. Median survival reached 10.5 months in women and 9.3 months in men. In patients under 50 years of age, one-year survival was 56.3% versus 44.9% in patients aged 50 and older, which refutes the common belief about a more aggressive course of cancer in young people. A significant discrepancy was revealed between official data (Form No. 7) and actual indicators: the reported proportion of early stages (43.2% on average in the Russian Federation) is significantly overestimated, while the actual five-year survival for stage I does not exceed 70% (compared to the expected ≥90%). An improvement in the quality of morphological verification was noted: the proportion of cases without morphological confirmation decreased from 23.3% to 9.2%. In the histological structure, adenocarcinoma without further specification predominates (66.0%). Despite the positive dynamics of survival, the real effectiveness of gastric cancer treatment remains insufficient due to late diagnosis and distortion of reporting data. The necessity of integrating population-based cancer registries into official statistics is substantiated.