Malignant neoplasms of the lip are a rare type of tumor. State reporting provides only a set of data for calculating incidence rates. The Population-Based Cancer Registry (PCR) database developed by us at the level of the Northwestern Federal District of the Russian Federation allowed, for the first time in Russia, to calculate a set of analytical indicators, such as the median survival, one-year and five-year cumulative survival rates of lip cancer patients, taking into account the detailed localization and histological structure. The aim of the study was to investigate the level and trends in survival of lip cancer patients in the Northwestern Federal District of the Russian Federation considering the localization and histological structures and the stage of the disease. The material of the study was the Population-based Cancer Registry of the Northwestern Federal District of the Russian Federation. Data processing was carried out using the methodology recommended by the International Association of Cancer Registries under the EUROCARE program. Unfavorable trends in the lip cancer incidence rate have been established in Russia and the Northwestern Federal District of the Russian Federation. The median survival remained within 68 years. Survival rates of patients have indicated a high level of treatment of patients with malignant lip neoplasms at the level of the Northwestern Federal District. Survival of patients in the first year of observation was: observed 89.3%, relative 93.8%. The five-year observed survival did not reach 50%, the relative exceeded 60%. Detailed localization development of the PCR data has revealed that patients with malignant neoplasms of the outer surface of the lower lip (C00.1) account for 60%. Histological characteristics of the registered patients have been significantly improved.

Malignant neoplasms of the tongue occupy 0.55% in the general structure of the cancer incidence in Russian population. No information on other parameters (the number of deaths, mortality of patients, their distribution by stages of the disease and other analytical indicators) is provided in the official reporting. The opportunity appeared only with the development of Population-based Cancer Registries (PCR) system, but this wealth of material is not used for the official reporting. Tongue cancer is a visual localization with a high mortality rate, which requires special attention. The study was conducted to investigate the state of Russian Oncology Service for tongue cancer patients with the calculations of one-year mortality rate, annual mortality rate, median survival, 1,3,5-year observed and relative survival rates, first time in Russia, at the level of the newly created Population-based Cancer Registry of the Federal District. In Russia, there has been little research on the analysis of the cancer survival rate at the population level. We have been conducting developments for all malignant tumors localizations since 2000 based on the St. Petersburg PCR database. The level of 5-year observed and relative survival rates for tongue cancer patients in Russia (St. Petersburg and the NWFD RF) has been found to be significantly lower than the EU average (Eurocare-4). To carry out this study, 5188 observations from the NWFD RF PCR database were selected. It has been established that during 4 periods of observation, the mortality rate for tongue cancer patients during the first year of observation in the NWFD RF has decreased under the C01 rubric (cancer of the base of the tongue) from 58.5 to 45.8%; and under the C02 rubric (malignant neoplasm of other and unspecified parts of tongue) from 54.5 to 42.7%. The five-year survival rate for tongue cancer patients has increased by 23.3%.

Malignant tongue neoplasms (C01, 02) belong to the group of rare visual tumor localizations. Only data on the primary tongue cancer registration can be obtained by the state statistics, mortality rate data are summarized and presented in the list of 14 headings of ICD-10-C00-14 - malignant neoplasms of lip, oral cavity and pharynx, it is impossible to obtain any analytical characteristics at the All-Russian or regional level (the distribution of patients by stages of the disease, mortality of patients in the first year of observation, accumulated patient population, etc.). This information can be obtained only from the databases created by the Population-based Cancer Registries (PCR) of a country. Aim. The aim is to study the prevalence of tongue cancer and the detailed structure of morbidity, to calculate a number of analytical indicators characterizing tongue cancer at the population level of the Federal District for the first time in Russia. Materials and methods. Based on the materials of the International Agency for Research on Cancer (IARC), statistical reference books of the P. Hertsen Moscow Oncological Research Institute, our own extensive materials and the newly created PCR database at the level of the Northwestern Federal District of Russia, to study all the possible aspects set in the research objectives, using a set of methodological techniques recommended by the IARC, of which we are a member No. 221. Results. The study has shown that tongue cancer morbidity rate of the population (standardized indicator the world standard) in the various countries from 1970 to 2010 has increased slightly or maintained its level. In Russia, such an assessment can be carried out only from 1989 to 2018. During this period, the incidence of tongue cancer among males has increased from 2.2 to 2.43 0/0000, among females from 0.4 to 0.71 0/0000. In the Northwestern Federal District of the Russian Federation, the incidence of males has reached 2.69, females 0.82 0/0000. The mortality rate of patients in the first year of observation (PCR database) has decreased from 2000 to 2018 from 59.5 to 43.1%, but remains significantly above the EU average.

Malignant neoplasms of the lip (C00) are rare types of malignancies. It is ranked 30 in terms of the structure of oncopathology in Russia and the Northwestern Federal District of the Russian Federation. There is a positive trend in the incidence rate as the proportion in the database of the Population-based Cancer Registry (PCR) of the Northwestern Federal Region of the Russian Federation takes modestly 0,4% (both sexes). It should be noted that according to the official reporting (Form No. 7) it is impossible to obtain any other criteria for assessing the effectiveness of combating this tumor in addition to the trends of morbidity. We have presented the estimation on the state of the effectiveness of anticancer measures regarding malignant tumors of the lip (C00) on the basis of the PCR database of Saint Petersburg. As of January 1, 2020 the Northwestern Federal Region of the Russian Federation (NWFD RF) includes 11 subjects with the population of 1 397 727. In February 2019 we created a unified database of malignant neoplasms of the Federal Region. In fact there has been organized the first in Russia Population-based Cancer Registry at the Federal Region level. Total number of registered lip cancer cases includes more than 1 million 350 thousand cases. To develop analytical criteria, only reliable materials with a number of 952791 cases including 2663 cases of malignant tumors of the lip were selected. Aim of the study: to determine the prevalence of malignant neoplasms of the lip, annual mortality, features of localization and histological structure. Materials and methods. The study was based on the reference books on the prevalence of malignant tumors (IARC publication Cancer on Five Continents volume XI, P.A. Herzen Institute of Medical Research, N.N. Petrov National Research Center of Oncology, the Population Cancer Registry database of the Northwestern Federal District of the Russian Federation). Standard research methods recommended by the International Association of Cancer Registries were used. Results of the study. The study has revealed a high level of lip cancer morbidity of the population in Russia and the North-Western Federal District against the background of indicators for economically developed countries, but the incidence rate is gradually decreasing. The highest standardized incidence rate of malignant tumors of the lip in the Northwestern Federal District of the Russian Federation remains among the male population of the Vologda, Pskov regions and the Komi Republic. We have established a special procedure for the death of patients with malignant neoplasms of the lip in the Northwestern Federal District of the Russian Federation. A surge in mortality from lip cancer has been revealed in women in the second, fourth, seventh, ninth and tenth years of follow-up, in men in the fourth, seventh and tenth, which requires fundamental research in search of the causes of the surge in mortality. Unfavorable annual mortality trends in patients with lip cancer in the Northwestern Federal District of the Russian Federation have been revealed. The features of localization and histological structure of malignant tumors of the lip have been established.