Instrumental clinical restaging, pathological evaluation, and tumor regression grading: how to assess the response to neoadjuvant chemoradiotherapy for rectal cancer

Abstract

Our results lead us to consider only pathologic evaluation to determine the response to neoadjuvant treatment: the application of tumor regression grading on the specimens obtained after combined neoadjuvant chemoradiotherapy and surgery is useful to plan a better therapeutic strategy on the ground of a quantitative evaluation of the response to neoadjuvant treatment; it shows it is an important comparable pathological feature, useful in comparing different protocols' results and differences between patient's response as well as prognostic factors.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients’ Prognosis

“…In fact, early-stage tumors (ie, T1/T2) have excellent prognosis and are suitably treated by surgery alone. 75 In contrast, locally advanced disease, defined as tumor with transmural extension (ie, T3/T4) or tumor involving the locoregional lymph nodes (ie, N1/N2), has been associated with a high rate of local recurrence of about 25% in patients treated with surgery alone. 76 In 1982, Heald et al 77 introduced TME, reducing the local relapse rate to 7% and increasing the anal sphincter preservation rate by more than 20%.…”

Predictors of tumor response after preoperative chemoradiotherapy for rectal adenocarcinomas

“…Some authors showed that both 5-year overall and diseasefree survival rates were lower in patients with neoplastic mesorectal microfoci [24]. In the same way, several studies showed that a pCR was associated with lower rates of local recurrence [25][26][27]. It can be hypothesized that this better oncological outcome could be explained by the lower rate of vascular and/or perineural invasion observed in the mesorectum of responder patients.…”

Utility of rectoscopy in the assessment of response to neoadjuvant treatment for locally advanced rectal cancer

“…As reported in other studies publications, when the rectoscopy strictly fulfils the criteria of a cCR and a negative biopsy is obtained, we can predict the probability of encountering a pCR. [ 24 25 26 ] Suzuki et al demonstrated that morphological changes on rectoscopy were significantly related to the degree of tumor shrinkage, but they only had a 2% pCR and failed to establish a statistically significant relationship between cCR and pCR. García-Aguilar et al[ 27 ] present similar data among patients with cT2N0 undergoing CRT where >90% cCR corresponded to ypT0 after local excision.…”