Objectives: Several TNM staging system editions were published over the years for renal cell carcinoma (RCC). Using a search strategy similar to the one used by the TNM process Subcommittee for "literature watch", we searched MEDLINE with the intent to critically analyze literature concerning the different TNM editions and the data regarding the optimal breakpoints to substratify localized RCC.
Material and methods: The electronic search was conducted as follows: "Neoplasm staging" [MeSH] AND "Carcinoma, Renal Cell" [MeSH]. At the end of a process of abstract analysis performed separately by three of the authors, 34 papers were included in the systematic review.
Results: All the 34 selected papers were retrospective studies. According to the 1987 version of TNM classification, no paper showed statistically significant cancer-specific survival probability differences between stage I and stage II RCC. According to the 1997 TNM version, the results were controversial. While a few papers found significantly different cancer-specific survival rates between stage I and stage II RCC, several others failed to do so. With the aim to stratify patients with localized RCC, most of the papers proposed an ideal breakpoint ranging from 4.5 to 5.5 cm.
Conclusion: This literature review highlighted that a correct definition of the staging of organ-confined RCC was far from being achieved and provided an appropriate synopsis of the available data for further update of the TNM staging system.