cR and pR: The Residual Tumor Classification Revisited

Excerpt

Introduced by the American Joint Committee on Cancer (AJCC) in 1978 [1] and subsequently established in the 4th edition of the Tumor, Node, Metastasis (TNM) system the definition and interpretation of the R Classification has significantly changed over time. R describes residual tumor following antitumor therapies and thus reflects therapy effects. Every report on a tumor specimen should include a statement concerning the R status [2]. The intention of the initial R Classification was a feedback to the surgeon concerning the completeness of the resection [3, 4]. For specific entities, e.g. colorectal cancer [5], the R Classification was further developed into a prognostic parameter [2]. In the following years it was extended from the locoregional tumor to metastases, thus shifting its meaning to a systemic residual tumor burden following any primary therapy [6‐9]. …