Breast Cancer in Argentina: Feasibility for the Implementation of the New TNM Staging System 2018 in A Middle-Income Country

Background: Breast Cancer (BC) is the most commonly diagnosed cancer amongst women worldwide and also in Argentine a “medium human development” and “middle- income” country with an estimated incidence rate of 71, 2 per 100,000 in 2012. The implementation of the new TNM system for the staging of BC proposed by the AJCC and published in the VIII edition (2017) implies a substantial change with respect to the number of parameters and the criteria used until the present. Purpose: Given the importance of BC as a health problem present and future in our country and the need to study, as required, a larger number of parameters for the correct diagnosis and treatment of this pathology, we decided to study the feasibility of applying the new TNM system (2017) to the cases of BC already diagnosed in order to evaluate, with the current health system and medical benefits, what parameters are the most difficult to obtain and why in order to comply with the requirements of this new staging system. Methods: The data of the necessary parameters were extracted from the database of the Collaborative Group for the Study of Female Breast Cancer in Argentine (www.cancerdemama2012. org.ar) a consortium of 64 physicians from 75, public (26) and private (49), health services, reported 1732 case patients studied during the years 2012-2013. The following parameters were recorded: a) anatomical (T, N, and M); b) biological factors (hormone receptors, Her-2-neu overexpression, tumor grade) and c) multigene panel testing performed in 1732 cases (2012- 13); for this data a survey was also carried out on its current realization in 1063 cases (2016-17). Results: Taking together the data of all the parameters required in the new system in 75.2% of the cases they are all present; in the remaining 24.8% cases, one or more of the parameters are missing. Breaking down this result among the 7 parameters that compose it, the anatomical results are: T (84.7%); N (88.8%) and M (94.5%); the study of hormone receptors is of 96.6%, the Her2- neu study of 92.5% and the tumor grade datum is 86.1%. The fulfillment of the gene-expression profile study (in both series) shows low frequencies of performance (0.23% v. 3, 19%). 41, 5% of cases fulfilled the established guidelines for recommendation of adjuvant chemotherapy on the basis of the gene-expression profile study. Conclusion: With the current health system and the medical benefits available it was possible to apply the new staging system in 75% of the total cases already diagnosed. Paradoxically of the BF those that were less studied were the anatomical ones while the HR and the HER2 were studied in values close to 90%. The recommended study of the gene profile shows very low percentages of realization, both in the past series and in the current survey, far from being useful to define the “risk” of patients with early stages breast cancer. In that cases where they could not perform some of the studies it is due to ignorance of the value of the study of certain required parameters and most often to cost problems or lack of recognition or reimbursement by a health system. Until the present time we are able to meet, in a significant percentage of cases, the requirements of the new version and provide good and updated diagnostic procedures and adequate treatment to our breast cancer patients. But with our current infrastructure doubts arise about the possibility of fulfilling future demands, in a mandatory way, of certain parameters (mainly genetic studies) for the staging of BC.