Tumour regression grading after chemoradiotherapy for locally advanced rectal cancer: A near pathologic complete response does not translate into good clinical outcome

Profiling of rectal cancers MRI in pathological complete remission states after neoadjuvant concurrent chemoradiation therapy

“…This illustrates the importance of standard curative surgery, emphasising that alternative and minimally invasive therapies, such as local excision or watchful waiting, should be adopted with caution. 33 In conjunction with previous reports, the present data show that the vast majority of patients with rectal cancer present post-CCRT with a broad spectrum of imaging features in residual lesions. Not infrequently, unexpected imaging presentations may be extreme and seem incongruous with pCR status.…”

Impact of neoadjuvant therapy on cancer-associated fibroblasts in rectal cancer

“…Rectal cancers undergo tumour regression by disappearance of cancer cells and replacement by fibrous or fibroinflammatory tissue. There is an excellent outcome for patients with a pathological complete response, but in a recent study patients with a near complete response unexpectedly fared poorly, indicating the need for a more thorough understanding of factors predicting metastasis-free survival [35]. Interestingly, foci of residual cancer cells surrounded by a fibrotic-type stroma show a shorter 5-year recurrence-free survival in multivariate analysis compared to residual cancer cells surrounded by a fibroinflammatory response [36].…”

Prediction of tumor response of rectal cancer cells via 3D cell culture and in�vitro cytotoxicity assay before initiating preoperative chemoradiotherapy

“…The current practice of local excision following good clinical response indicated that metastatic lymph nodes may regress at the same level as the primary tumor following preop-CRT, which was supported by the clinical observations (31,32). In contrast, a study reported 28.5% lymph node positivity in patients who exhibited pCR (ypT0) (11). Moreover, Choi et al (33) demonstrated that lymph node regression grade (LRG) following preop-CRT was the only independent factor associated with relapse-free survival in patients with ypN-positive rectal cancer, who underwent preop-CRT.…”

“…There is still some controversy regarding this topic, and one of the main concerns with delaying the surgery or the local excision approach is the difficulty of predicting LNM even in the case of good clinical response. Swellengrebel et al (11) reported that 28.5% of patients with no residual tumor in the rectal wall had persistent regional LNM and 41% of near-complete response patients had ypT3 stage. Although several researchers have investigated predictors of ypN-positive status following preop-CRT, the studies are limited, as the factors used in the nomograms are often difficult to obtain prior to radical resections (12)(13)(14).…”