Systematic review and meta-analysis of outcomes following pathological complete response to neoadjuvant chemoradiotherapy for rectal cancer

Abstract

Background: Following neoadjuvant chemoradiotherapy (CRT) and interval proctectomy, 15-20 per cent of patients are found to have a pathological complete response (pCR) to combined multimodal therapy, but controversy persists about whether this yields a survival benefit. This systematic review evaluated current evidence regarding long-term oncological outcomes in patients found to have a pCR to neoadjuvant CRT. Results: A total of 724 studies were identified for screening. After applying inclusion and exclusion criteria, 16 studies involving 3363 patients (1263 with pCR and 2100 without) were included (mean age 60 years, 65·0 per cent men). Some 73·4 per cent had a sphincter-saving procedure. Mean follow-up was 55·5 (range 40-87) months. For patients with a pCR, the weighted mean local recurrence rate was 0·7 (range 0-2·6) per cent. Distant failure was observed in 8·7 per cent. Five-year overall and disease-free survival rates were 90·2 and 87·0 per cent respectively. Compared with non-responders, a pCR was associated with fewer local recurrences (odds ratio (OR) 0·25; P = 0·002) and less frequent distant failure (OR 0·23; P < 0·001), with a greater likelihood of being alive (OR 3·28; P = 0·001) and disease-free (OR 4·33, P < 0·001) at 5 years. Conclusion:A pCR following neoadjuvant CRT is associated with excellent long-term survival, with low rates of local recurrence and distant failure.

Prognostic Significance of Tumor Regression in Locally Advanced Rectal Cancer after Preoperative Radiochemotherapy

“…Meta analysis of 12 larger studies worldwide reports 90.2% 5-year survival rate in pCR patients (p = 0.0001) 15 ; similar percentage (90% or more) is mentioned in various other studies 2,4,16 , while others failed to prove relation between pCR and better survival. 15 In the literature, strong evidence exists that patients with pCR have very few local recurrences (2-5% in 5 years) and that there are statistically significant differences, if groups of patients with pCR are compared to those who failed to respond to preoperative treatment. 4,16 It is important to state that in some no local recurrences at all were found in groups of pCR patients.…”

Complete Clinical Response in Rectal Adenocarcinoma: Review of Treatment Options

“…With LE, mesorectal lymph nodes are not excised, and lymph node status is correlated with prognosis. A systemic review [43] reported that between 2% to 27% of patients with ypT0 have positive nodes on final pathology. In addition, while LE generally tolerated well with low complication rates, the addition of nCRT prior to LE increases complication rates in current studies.…”

Two Cases of Pathological Complete Response to Neoadjuvant Chemoradiation Therapy in Pancreatic Cancer

“…[10][11][12][13]15,20,21 In general, the margin-free resection rate or 6-month progression-free survival is used as an effective surrogate marker of NACRT efficacy in PDA. The pathological response rate is also gaining recognition as an important surrogate.…”

“…8,9 For several different types of carcinoma, in some organs, pathological complete response (pCR) to neoadjuvant therapy is correlated with a lower frequency of local recurrence and better survival. [10][11][12][13][14][15] However, very few studies have analyzed the clinicopathological significance of pCR in patients with PDA who received neoadjuvant therapy. 9,16,17 Here we report two cases of pCR to NACRT in PDA, including detailed pathological findings of resected tissues.…”