Tumor Regression Grades: Can They Influence Rectal Cancer Therapy Decision Tree?

Abstract

Background. Evaluating impact of tumor regression grade in prognosis of patients with locally advanced rectal cancer (LARC). Materials and Methods. We identified from our colorectal cancer database 168 patients with LARC who received neoadjuvant therapy followed by complete mesorectum excision surgery between 2003 and 2011: 157 received 5-FU-based chemoradiation (CRT) and 11 short course RT. We excluded 29 patients, the remaining 139 were reassessed for disease recurrence and survival; the slides of surgical specimens were reviewed and classified according to Mandard tumor regression grades (TRG). We compared patients with good response (Mandard TRG1 or TRG2) versus patients with bad response (Mandard TRG3, TRG4, or TRG5). Outcomes evaluated were 5-year overall survival (OS), disease-free survival (DFS), local, distant and mixed recurrence. Results. Mean age was 64.2 years, and median followup was 56 months. No statistically significant survival difference was found when comparing patients with Mandard TRG1 versus Mandard TRG2 (p = .77). Mandard good responders (TRG1 + 2) have significantly better OS and DFS than Mandard bad responders (TRG3 + 4 + 5) (OS p = .013; DFS p = .007). Conclusions. Mandard good responders had a favorable prognosis. Tumor response (TRG) to neoadjuvant chemoradiation should be taken into account when defining the optimal adjuvant chemotherapy regimen for patients with LARC.

Prognostic and Therapeutic Potential Implications of Genetic Variability in Prostaglandin E2 Pathway Genes in Rectal Cancer

“…Concerning assessment of histological tumor response to CRT, we decided to adopt a two-point classification system based on Mandard TRG to split the patients into subgroups with significantly different prognosis, according to previous studies (33,34). This methodology allows us to find prognosis factors with significance in multivariate analysis.…”

Tumor regression grades: Potential outcome predictor of locally advanced rectal adenocarcinoma after preoperative radiotherapy

“…Response to neoadjuvant therapy is outlined in Table 2. Classification of TRG according to the Mandard system allowed us to define two groups as previously described [3] : TRG1/2 and TRG3-5. We verified a good response to 30 Gy/10 fractions pre-RT in 24 patients (ypCR in 5%-12.6%) and a bad response in 166 patients (87.4%).…”

“…Surgery remains the primary therapeutic tool for rectal cancer, and locoregional recurrence has been reduced by total mesorectal excision (TME) of cancers of the middle and lower rectum [3] . Preoperative radiotherapy (pre-RT), including short-or long-term courses, followed by TME can induce tumor regression and facilitate subsequent resection, resulting in improved local control and survival [4] .…”

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

“…Moreover, the rate of lymph node (LN) metastasis that accompanies pathological complete remission (pCR) is low, compared with an increase in the prevalence of LN metastasis with a greater degree of residual disease. 1,4,5 Following CCRT, radical surgical resection remains the standard treatment of locally advanced rectal cancer, although less aggressive approaches (local excision or close observation) may be elected in instances where pCR is reasonably assured. 1 In patients responding well to CCRT, results of local excisions have been encouraging, marked by relatively low risk of local recurrence and long-term survival comparable to radical surgery, with no need of a permanent stoma.…”