Prognostic Role of Pathological Complete Response in Early Stage Epithelial Solid Tumors

Neoadjuvant chemotherapy was originally designed to convert inoperable cancer. Nowadays, this concept has expanded since it can also offer the possibility to evaluate markers of response such as pathological complete response (pCR) with possible implications in long-term prognostic outcomes. A substantial body of literature tried to evaluate the ability of pCR to fulfill the conditions required to establish a preliminary endpoint, such as pCR, as a surrogate for the final endpoint, the overall survival (OS) but no systematic reviews have been performed yet. In this review we systematically analyzed the prognostic role of pCR in various cancers (breast, gastro-oesophageal, rectal, ovarian, bladder, lung) in which neoadjuvant treatment is a standard of care, evaluating articles published in the English language of phase III or phase II randomized controlled trials and meta-analyses. Since the continue development of immunotherapy in earlier stage, it has also been considered the impact of tumor-infiltrating lymphocyte on pCR.