Pathologic response to neoadjuvant treatment in locally advanced rectal cancer and impact on outcome

Abstract

.Background: Downstaging and pathologic complete response (pCR) after chemoradiotherapy (CRT) may improve progression-free survival and overall survival (OS) after curative therapy of locally advanced adenocarcinoma of rectum. The purpose of this study is to evaluate the pathologic response subsequent to neoadjuvant chemoradiation in locally advanced rectal adenocarcinoma and any impact of response on oncological outcome [disease-free survival (DFS), OS].Methods: A total of 127 patients with histologically-proven rectal adenocarcinoma, locally advanced, were treated with preoperative radiotherapy and concurrent 5-fluorouracil (5 FU), and followed by curative surgery. Pathologic response to neoadjuvant treatment was evaluated by comparing pathologic TN (tumour and nodal) staging (yp) with pre-treatment clinical staging. DFS and OS were compared in patients with:pCR, partial pathologic response and no response to neoadjuvant therapy. showed distant metastasis, none showed local recurrence. In the downstaged group, nine developed distant failure and two had local recurrence (14.86%). Distant failure was seen in 26.47% [9] of those with no response to neoadjuvant treatment. DFS and OS rates for all groups were 82.67% and 88.97% respectively. ResultsPatients with pCR showed 89.47% DFS and 94.7% OS. In partial responders, DFS was 85.1% and OS was 90.5%. In non-responders, DFS and OS were 73.5% and 82.3% respectively. Patients with pCR had a significantly greater probability of DFS and OS than non-responders. Rectal cancer-related death was 11.02% [14]: one patient (5.26%) with pCR, 9.47% [7] in the downstaged group and 17.64% [6] of nonresponders. Conclusions:The majority of patients showed some response to neoadjuvant treatment. Findings of this study indicate tumour response to neoadjuvant CRT improves the long-term outcome, with a better result in patients with pCR.

Lack of Pathological Response of Rectal Cancer to Neoadjuvant Chemoradiotherapy is Associated with Poorer Long-Term Oncological Outcomes

“…To conclude, the primary finding of this study is that rectal cancer patients with poor or no response to neoadjuvant treatment based on the Modified Ryan Scheme for Tumor Regression Score demonstrate increased risk for non-curative resection (R1, R2 resection), conversion to open surgery, and poor long term, oncologic outcomes (recurrence and DRM), as compared with patients with any better level of response (TRS 0-2). The systemic mode of recurrence of TRS 3 tumors found in this study and others, suggests that these tumors have an inherently aggressive, malignant biologic phenotype that makes them less responsive to CRT and also increases their propensity to metastasize [24,33,34].…”

“…The uniqueness of this study lies in its focus on the long-term oncological outcomes of the non-responder TRS 3 patients. Other studies reached the same conclusions regarding the poor prognosis and high recurrence rate among non-responder patients [33][34][35][36]. The major limitation of this study is its retrospective nature and the relatively small sample size, which was probably the reason for our inability to demonstrate statistically significant differences in distant recurrence and DRM rates between the groups.…”

“…Also noteworthy is this patient did not receive adjuvant chemotherapy. Despite the particulars of this case, other studies have reported that in the rare cases of recurrence among patients with pCR, the pattern of failure was systemic [33,34]. Conversion from laparoscopic to open surgery was another differentiating factor.…”

Prognostic significance of tumour regression grade after neoadjuvant chemoradiotherapy for a cohort of patients with locally advanced rectal cancer: an 8‐year retrospective single‐institutional study

“…Using a prospectively maintained rectal cancer database, we identified 185 consecutive patients who had received NACRT prior to TME between February 2005 and June 2013. The following inclusion criteria were adopted: (1) a histological diagnosis confirmed in all cases by an experienced gastrointestinal pathologist; (2) Stage II and III confirmed by endoscopic ultrasonography (EUS); (3) tumours less than 10 cm from the anal verge classified as low (0-5 cm from the anal verge), mid (5-8 cm from the anal verge) or high (8-10 cm from the anal verge); (4) received treatment and followup at the PUMCH.…”

LINC00152 is a potential biomarker involved in the modulation of biological characteristics of residual colorectal cancer cells following chemoradiotherapy

“…The prognosis of patients with locally advanced rectal cancer who underwent neoadjuvant radiotherapy and chemotherapy and achieved a pCR was revealed to be significantly improved compared with patients who did not achieve a pCR ( 12 ). However, the rate of pCR following neoadjuvant chemoradiotherapy is only ~10% ( 13 ).…”