Prognostic value of Dworak grade of regression (GR) in patients with rectal carcinoma treated with preoperative radiochemotherapy

Relevance of shrinkage versus fragmented response patterns in rectal cancer

AIMS

Partial response to neoadjuvant chemoradiotherapy (CRT) presents with one of two main response patterns: shrinkage or fragmentation. This study investigated the relevance of these response patterns in rectal cancer, correlation with other response indicators, and outcome.

METHODS AND RESULTS

The study included a test (n = 197) and a validation cohort (n = 218) of post-CRT patients with rectal adenocarcinoma not otherwise specified and a partial response. Response patterns were scored by two independent observers using a previously developed three-step flowchart. Tumour regression grading (TRG) was established according to both the College of American Pathologists (CAP) and Dworak classifications. In both cohorts, the predominant response pattern was fragmentation (70% and 74%), and the scoring interobserver agreement was excellent (k = 0.85). Patients with a fragmented pattern presented with significantly higher pathological stage (ypTNM II-IV, 78% versus 35%; P < 0.001), less tumour regression with Dworak (P = 0.004), and CAP TRG (P = 0.005) compared to patients with a shrinkage pattern. As a predictor of prognosis, the shrinkage pattern outperformed the TRG classification and stratified patients better in overall (fragmented pattern, hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.19-3.50, P = 0.008) and disease-free survival (DFS; fragmented pattern, HR 2.50, 95% CI 1.23-5.10, P = 0.011) in the combined cohorts. The multivariable regression analyses revealed pathological stage as the only independent predictor of DFS.

CONCLUSIONS

The heterogeneous nature of tumour response following CRT is reflected in fragmentation and shrinkage. In rectal cancer there is a predominance of the fragmented pattern, which is associated with advanced stage and less tumour regression. While not independently associated with survival, these reproducible patterns give insights into the biology of tumour response.

Lymph node regression grading of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Neoadjuvant chemoradiotherapy (nCRT) and total rectal mesenteric excision are the main standards of treatment for locally advanced rectal cancer (LARC). Lymph node regression grade (LRG) is an indicator of prognosis and response to preoperative nCRT based on postsurgical metastatic lymph node pathology. Common histopathological findings in metastatic lymph nodes after nCRT include necrosis, hemorrhage, nodular fibrosis, foamy histiocytes, cystic cell reactions, areas of hyalinosis, residual cancer cells, and pools of mucin. A number of LRG systems designed to classify the amount of lymph node regression after nCRT is mainly concerned with the relationship between residual cancer cells and regressive fibrosis and with estimating the number of lymph nodes existing with residual cancer cells. LRG offers significant prognostic information, and in most cases, LRG after nCRT correlates with patient outcomes. In this review, we describe the systematic classification of LRG after nCRT, patient prognosis, the correlation with tumor regression grade, and the typical histopathological findings of lymph nodes. This work may serve as a reference to help predict the clinical complete response and determine lymph node regression in patients based on preservation strategies, allowing for the formulation of more accurate treatment strategies for LARC patients, which has important clinical significance and scientific value.

Lymph Node Regression to Neoadjuvant Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer: Prognostic Implication and a Predictive Model

AIM

Currently, few studies have focused on the prognostic impact of lymph node regression to neoadjuvant chemoradiotherapy (NCRT) in rectal cancer. This study aimed to explore the prognostic impact of lymph node regression grade (LRG) in patients with locally advanced rectal cancer (LARC) following NCRT and radical surgery and develop a predictive nomogram for disease-free survival (DFS).

METHODS

LARC patients undergoing NCRT and radical surgery between 2013 and 2014 were enrolled and divided into LRG low (≤ 2), middle (3-9), and high (≥ 10) groups. Clinicopathological characteristics and survival outcomes were compared. Predictors for DFS were identified by Cox regression analysis, and a nomogram was constructed.

RESULTS

A total of 257 LARC patients were eligible, including LRG low (n = 149), middle (n = 59), and high (n = 49) groups. Higher LRG score was associated with higher TRG, more advanced ypT and ypN stages, and poorer OS and DFS (all P < 0.001). Cox regression analysis demonstrated that tumor differentiation (poor and anaplastic, HR = 2.048, P = 0.048), ypTNM stage (HR = 2.389, P = 0.015), and LRG-sum (HR = 1.020, P = 0.029) were independent prognostic determinants for DFS after NCRT. A nomogram for DFS was developed with a C-index of 0.68 (95%CI 0.64-0.72).

CONCLUSION

LRG is an important prognostic indicator for DFS in LARC patients after NCRT. A predictive nomogram based on LRG was developed to guide more tailored adjuvant treatment and surveillance.

Polymorphism of formyl peptide receptor 1 (FPR1) reduces the therapeutic efficiency and antitumor immunity after neoadjuvant chemoradiotherapy (CCRT) treatment in locally advanced rectal cancer

Immunosurveillance and immunoscavenging prompted by preoperative chemoradiotherapy (CCRT) may contribute to improve local control and increase survival outcomes for patients with locally advanced rectal cancer (LARC). In this study, we investigated several genotypes of pattern recognition receptors (PRRs) and their impact on therapeutic efficacy in LARC patients treated with CCRT. We found that homozygosis of formyl peptide receptor 1 (FPR1) (E346A/rs867228) was associated with reduced 5-year overall survival (OS) by Kaplan-Meier analysis (62% vs. 81%, p = 0.014) and multivariate analysis [hazard ratio (HR) = 3.383, 95% CI = 1.374-10.239, p = 0.007]. Moreover, in an animal model, we discovered that the FPR1 antagonist, Boc-MLF (Boc-1), reduced CCRT therapeutic efficacy and decreased cytotoxic T cells and T effector memory cells after chemoradiotherapy treatment. Pharmacologic inhibition of FPR1 by Boc-1 decreased T lymphocyte migration to irradiated tumor cells. Therefore, these results revealed that the FPR1 genotype participates in CCRT-elicited anticancer immunity by reducing T lymphocytes migration and infiltration, and that the FPR1-E346A CC genotype can be considered an independent biomarker for chemo- and radiotherapy outcomes.

Even a partial pathological response is associated with lower relapse rates in patients with operable rectal cancer undergoing neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy to treat locally advanced rectal cancer is an effective therapeutic strategy for the prevention of local recurrence and distant organ metastasis after surgery.

OBJECTIVES

To assess the prognostic significance of histopathological tumor response in rectal cancer patients undergoing neoadjuvant chemotherapy.

METHODS

This study included patients with operable rectal cancer who received neoadjuvant chemotherapy using the FOLFOX regimen (5-fluorouracil, l-leucovorin, and oxaliplatin) in a hospital between February 2012 and November 2017. The main outcome measure was disease-free survival with respect to histopathological response to neoadjuvant chemotherapy in resected specimens.

RESULTS

The median follow-up was 32 months. Of 48 patients treated with neoadjuvant FOLFOX, 24 (50%) were classified as responders, which included two patients with pathological complete response and 22 patients with partial response. The remaining 24 patients (50%) were classified as nonresponders. Responders had a significantly better 3-year disease-free survival than nonresponders (86% vs. 62%, p = .02).

CONCLUSIONS

Patients whose surgical specimens show a pathological complete response or partial response have good oncologic outcomes.

Carcinoembryonic Antigen Improves the Performance of Magnetic Resonance Imaging in the Prediction of Pathologic Response after Neoadjuvant Chemoradiation for Patients with Rectal Cancer

PURPOSE

The purpose of this study was to investigate the role of carcinoembryonic antigen (CEA) levels in improving the performance of magnetic resonance imaging (MRI) for the prediction of pathologic response after the neoadjuvant chemoradiation (NCRT) for patients with rectal cancer.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 524 rectal cancer patients who underwent NCRT and total mesorectal excision between January 2009 and December 2014. The performances of MRI with or without CEA parameters (initial CEA and CEA dynamics) for prediction of pathologic tumor response grade (pTRG) were compared by receiver-operating characteristic analysis with DeLong's method. Cox regression was used to identify the independent factors associated to pTRG and disease-free survival (DFS) after NCRT.

RESULTS

The median follow-up was 64.0 months (range, 3.0 to 113.0 months). On multivariate analysis, poor tumor regression grade on MRI (mrTRG; p < 0.001), initial CEA (p < 0.001) and the mesorectal fascia involvement on MRI before NCRT (mrMFI; p=0.054) showed association with poor pTRG. The mrTRG plus CEA parameters showed significantly improved performances in the prediction of pTRG than mrTRG alone. All of mrTRG, mrMFI, and initial CEA were also identified as independent factors associated with DFS. The initial CEA further discriminated DFS in the subgroups with good mrTRG or that without mrMFI.

CONCLUSION

The CEA parameters significantly improved the performance of MRI in the prediction of pTRG after NCRT for patients with rectal cancer. The DFS was further discriminated by initial CEA level in the groups with favorable MRI parameters.

Non-operative management of rectal cancer: understanding tumor biology

The management of locally-advanced rectal cancer involves a combination of chemotherapy, chemoradiation, and surgical resection to provide excellent local tumor control and overall survival. However, aspects of this multimodality approach are associated with significant morbidity and long-term sequelae. In addition, there is growing evidence that patients with a clinical complete response to chemotherapy and chemoradiation treatments may be safely offered initial non-operative management in a rigorous surveillance program. Weighed against the morbidity and significant sequelae of rectal resection, recognizing how to best optimize non-operative strategies without compromising oncologic outcomes is critical to our understanding and treatment of this disease.

Single nucleotide polymorphism of <italic>GSTP1</italic> and pathological complete response in locally advanced rectal cancer patients treated with neoadjuvant concomitant radiochemotherapy

Purpose

Standard treatment for locally advanced rectal cancer consists of neoadjuvant radiochemotherapy with concomitant fluoropyrimidine or oxaliplatin and surgery with curative intent. Pathological complete response has shown to be predictive for better outcome and survival; nevertheless there are no biological or genetic factors predictive for response to treatment. We explored the correlation between the single nucleotide polymorphisms (SNPs) GSTP1 (A313G) and XRCC1 (G28152A), and the pathological complete response and survival after neoadjuvant radiochemotherapy in locally advanced rectal cancer patients.

Materials and Methods

Genotypes GSTP1 (A313G) and XRCC1 (G28152A) were determined by pyrosequencing technology in 80 patients affected by locally advanced rectal cancer.

Results

The overall rate of pathological complete response in our study population was 18.75%. Patients homozygous AA for GSTP1 (A313G) presented a rate of pathological complete response of 26.6% as compared to 8.5% of the AG+GG population (p = 0.04). The heterozygous comparison (AA vs. AG) showed a significant difference in the rate of pathological complete response (26.6% vs. 6.8%; p = 0.034). GSTP1 AA+AG patients presented a 5- and 8-year cancer-specific survival longer than GSTP1 GG patients (87.7% and 83.3% vs. 44.4% and 44.4%, respectively) (p = 0.014). Overall survival showed only a trend toward significance in favor of the haplotypes GSTP1 AA+AG. No significant correlations were found for XRCC1 (G28152A).

Conclusion

Our results suggest that GSTP1 (A313G) may predict a higher rate of pathological complete response after neoadjuvant radiochemotherapy and a better outcome, and should be considered in a more extensive analysis with the aim of personalization of radiation treatment.

Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis

AIM

The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy; however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature.

METHOD

This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies.

RESULTS

There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97; P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively.

CONCLUSION

In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR.

Predictors of Sensitivity to Preoperative Chemoradiotherapy of Rectal Adenocarcinoma

Objectives

The purpose of the study was to identify predictive factors of tumor response to preoperative chemoradiotherapy for rectal adenocarcinoma.

Methods

Ninety-eight patients with nonmetastatic rectal adenocarcinoma received preoperative concurrent chemoradiotherapy and underwent mesorectal excision. After treatment, tumor response according to tumor regression grade were evaluated. The correlation of clinicopathologic factors to tumor response was analyzed.

Results

The results from a univariate analysis indicated that pretreatment carcinoembryonic antigen level ≤3.0 ng/ml (P = 0.002), non-fixed tumor (P = 0.001), and tumor circumferential extent ≤50% (P = 0.001) were associated significantly with a good tumor response. They also indicated that pretreatment positive lymph nodes (P = 0.032) were associated significantly with a poor tumor response. In multivariate analysis, the results indicated that pretreatment carcinoembryonic antigen level (hazard ratio, 2.930; P = 0.003), tumor mobility (hazard ratio, 2.651; P = 0.002) and circumferential extent of tumor (hazard ratio, 2.394; P = 0.019) independently predicted a good pathologic response rate. Pretreatment positive lymph nodes were not significantly associated with a good response (hazard ratio, 0.361; P = 0.191).

Conclusions

Pretreatment carcinoembryonic antigen level, tumor mobility and circumferential extent of tumor may be helpful in predicting responsiveness in rectal adenocarcinoma to preoperative chemoradiotherapy, although the results should be confirmed in larger, more homogeneous studies.

Associations of tumor regression grade with outcomes in patients with locally advanced rectal cancer treated with preoperative two-week course of radiotherapy

Purpose

Studies concerning tumor regression grade (TRG) after two-week course of radiotherapy (RT) are limited. We tried to assess associations of TRG and outcomes in patients with locally advanced rectal cancer (LARC) treated with preoperative two-week course of RT.

Methods

356 consecutive LARC patients were retrospectively assessed. Patients with complete/intermediate (TRG1-3) and poor (TRG4-5) regressions were compared for overall survival (OS), disease-free survival (DFS) and metastasis-free survival (MFS).

Results

By univariate analysis, pretreatment and postoperative factors including TNM stages, ypT, ypN, surgical procedure, pathological grade, and TRG impacted survival outcomes. Complete/intermediate regressions (TRG1-3) had significantly improved survival outcomes compared with poor ones (TRG4-5) (5y-OS, 85.8% vs. 65.8%, P=0.001; 5y-DFS, 76.0% vs. 53.7%, P<0.001; 5y-MFS, 84.2% vs. 66.7%, P<0.001). Multivariate analysis showed that ypN (P<0.001) and pathological grade (P=0.018) were the most important independent prognostic factors for DFS. ypT (P=0.014) and ypN (P=0.001) were the independent prognostic factors for MFS. Meanwhile, ypT (P=0.009), ypN (P=0.001), surgical procedure (p=0.001), and TRG (p=0.019) were the independent prognostic factors for OS.

Conclusions

Complete/intermediate TRG regressions had a more favorable prognosis than the poor group. When treated with preoperative two-week course of RT; ypT, ypN, surgical procedure, and TRG seem to affect OS.

Tumor Regression Grade After Neoadjuvant Chemoradiation and Surgery for Low Rectal Cancer Evaluated by Multiple Correspondence Analysis: Ten Years as Minimum Follow-up

BACKGROUND

The role of Mandard's tumor regression grade (TRG) classification is still controversial in defining the prognostic role of patients who have undergone neoadjuvant chemoradiation (CRT) and total mesorectal excision. The present study evaluated multiple correspondence analysis (MCA) as a tool to better cluster variables, including TRG, for a homogeneous prognosis.

PATIENTS AND METHODS

A total of 174 patients with a minimum follow-up period of 10 years were stratified into 2 groups: group A (TRG 1-3) and group B (TRG 4-5) using Mandard's classification. Overall survival and disease-free survival were analyzed using univariate and multivariate analysis. Subsequently, MCA was used to analyze TRG plus the other prognostic variables.

RESULTS

The overall response to CRT was 55.7%, including 13.2% with a pathologic complete response. TRG group A correlated strictly with pN status (P = .0001) and had better overall and disease-free survival than group B (85.1% and 75.6% vs. 71.1% and 67.3%; P = .06 and P = .04, respectively). The TRG 3 subset (about one third of our series) showed prognostically heterogeneous behavior. In addition to multivariate analysis, MCA separated TRG 1 and TRG 2 versus TRG 4 and TRG 5 well and also allocated TRG 3 patients close to the unfavorable prognostic variables.

CONCLUSION

TRG classification should be used in all pathologic reports after neoadjuvant CRT and radical surgery to enrich the prognostic profile of patients with an intermediate risk of relapse and to identify patients eligible for more conservative treatment. Thus, MCA could provide added value.

Prognostic influence of histopathological regression patterns in rectal adenocarcinoma receiving neoadjuvant therapy

BACKGROUND

Neoadjuvant chemoradiation therapy (CRT) is an important management strategy in rectal carcinoma. Different systems grading response have shown varying prognostic influence.

METHODS

To analyze the prognostic influence of pathological response in a series of 183 patients with rectal carcinoma receiving neoadjuvant therapy. To determine the prognostic significance of the histopathological patterns of response.

RESULTS

A total of 183 patients from two hospitals. The concordance rate between pathologists was good. In total, 18% of the patients showed grade 0 (complete response), 31.7% grade 1, 19.2% grade 2 and 31.1% grade 3 regression. T down-staging was found in 51.9% of the cases. 46 patients recurred and 18 died of disease (median follow-up time: 39 months). We found a statistically significant association between pathological response and pT stage and down-staging. Inflammatory reaction in the tumor bed was significantly associated to regression and prognosis. Cox's multivariate analysis of survival revealed that down-staging and presence of mucin pools in the tumor bed behaved as significant predictors of recurrence and regression grade and mucin pools as significant predictors of survival.

CONCLUSIONS

Pathological response is an important surrogate marker of prognosis in some large series, but results are varying. There are many systems to grade regression and this makes it difficult to compare the results by different groups. It is important to report the specific pattern of response, for some of them may have prognostic relevance. We feel there is an urgent need to develop standarized protocols and employ a universal regression scheme if we intend to use this factor to guide therapy.

Prognostic significance of tumor regression in lymph nodes after neoadjuvant therapy for rectal carcinoma

Neoadjuvant therapy (NAT) is mainly indicated for locally advanced rectal carcinoma. Many reports have shown that regression of the primary tumor is a prognostic factor. However, few reports to date have analyzed the potential prognostic significance of lymph node regression in rectal carcinoma. The aim of the present study is to describe the pattern of tumor regression in lymph nodes after NAT for rectal carcinoma and its potential prognostic significance. We have retrospectively reviewed 106 cases of rectal carcinoma treated at a single institution. We have retrieved data from the patients and reviewed the histopathological slides to evaluate tumor regression both of the primary tumor and of LN metastases. Prognosis has been defined both in terms of disease-free survival (DFS) and disease-specific survival (DSS). Of the patients, 16% showed complete response of the primary tumor, while 24% showed poor response, according to the CAP regression grading system. Absence of lymph node involvement after therapy was found in 80% of the patients (ypN0 cases), while 20% were ypN+. We reviewed 639 LN; 85 were involved by tumor, and 170 showed histological signs of tumor regression. The main pattern of tumor regression in lymph nodes was fibrosis (66.3%), followed by hystiocytosis (29.1%) and mucin pools (4.6%). We found histological signs of regression in 57% of ypN0 cases and 76% of ypN+ cases. We found a significant association between regression grade of the primary tumor and of lymph node metastases. For ypN0 patients with persistence of the primary tumor after NAT, the median DFS was significantly shorter in patients showing tumor regression in the LN. In a Cox multivariate survival model for DFS, this prognostic influence was independent of the regression grade of the primary tumor and also of the ypTNM stage. We found no significant association between any factor and DSS. The pattern of tumor regression in lymph nodes was not significantly associated with prognosis. Tumor regression in lymph nodes is an important prognostic factor in rectal carcinoma after NAT and should be specifically looked for and included in pathology reports.

Pathological Assessment of the AJCC Tumor Regression Grading System After Preoperative Chemoradiotherapy for Chinese Locally Advanced Rectal Cancer

We used American Joint Committee on Cancer (AJCC) Staging Manual system to assess the prognostic significance of tumor regression grading (TRG) for locally advanced rectal cancer (LARC) (T3/4 or N+) patients who were treated with preoperative chemoradiotherapy (CRT).The 4 AJCC-TRG classifications were evaluated on surgical specimens from 295 LARC patients receiving CRT. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were estimated using Kaplan-Meier method and Cox regression model.Classifications of TRG 0, 1, 2, and 3 were found in 27.5%, 19.3%, 45.7%, and 7.5% of the resected specimens, respectively. Three-year OS was 95.5% for TRG0, 91.5% for TRG1, 84.8% for TRG2, and 85.7% for TRG3 (P = 0.035). Three-year DFS was 89.0% for TRG0, 74.4% for TRG1, 70.9% for TRG2, and 62% for TRG3 (P = 0.018). By multivariate analysis, AJCC-TRG (P = 0.033), residual lymph node metastasis (ypN+) (P < 0.001) and pretreatment CA19-9 level (P = 0.035) were significant predictors of OS. Pathological T category (P = 0.006) and nodal status (P < 0.001) after CRT were the most important independent prognostic factors for DFS.AJCC-TRG is a prognostic factor for LARC patients receiving CRT, independent of pathological staging.

MRI tumor volume reduction rate vs tumor regression grade in the pre-operative re-staging of locally advanced rectal cancer after chemo-radiotherapy

OBJECTIVE

To compare tumor volume reduction rate (TVRR) measured by MR volumetry after preoperative chemoradiotherapy (CRT) and pathological tumor regression grade (TRG) in locally advanced rectal cancer (LARC).

MATERIAL AND METHODS

In total, 20 patients with LARC (cT3-T4) treated with CRT followed by Total Mesorectal Excision (TME) between April 2011 and April 2013 were analyzed retrospectively. Pre- and post- CRT tumor volumes (MR volumetry) were measured on 3D MR sequences. TVRR was determined using the equation TVRR (%)=(pre-CRT tumor volume-post-CRT tumor volume)×100/pre-CRT tumor volume. The downstaging (defined as ypT0-T2) of tumor mass was evaluated and the correlation between TVRR and TRG was calculated with the method proposed by Dworak using the Spearman rank test.

RESULTS

The median TVRR was 77.3% (range, 26.4-99.3%); TVRR was >60% in 18 cases (90%) and in 8 of these patients (44.4 %) it was >80%. Downstaging of tumor lesions was obtained in 15 patients (75%). In 4 cases there was a complete tumor regression (TRG4) at histological examination and in the same patients there was also a TVRR>80% measured by MR volumetry. A statistically significant correlation between TVRR and TRG (r(s)=0.5466, p=0.0126) was observed.

CONCLUSION

TVRR after preoperative CRT correlates with TRG in LARC. The MR volumetry is a prognostic factor to estimate the tumor response after preoperative CRT. TVRR data may be an useful biomarker for tailoring surgery and postoperative adjuvant chemotherapy.

Tumor regression in rectal cancer after intensified neoadjuvant chemoradiation: a morphometric and clinicopathological study

BACKGROUND

High interobserver variation is a well known drawback of conventional tumor regression grading, and reaching consensus among pathologists may require a considerable effort. Therefore, in this study, morphometry was tried to assess tumor regression, and its prognostic role was explored.

METHODS

Tumor regression was quantified by a point counting method to yield tumor area fraction (TAF) as an index of remaining vital tumor.

RESULTS

In a series of 104 patients with clinically advanced rectal cancer treated with neoadjuvant radiochemotherapy, TAFs were distributed continuously towards complete regression which was observed in 8.7% of the cases. Plotting TAFs grouped by a conventional regression grading (Dworak's) revealed considerable overlap between groups. In a control series of untreated cancers, only TAFs of cancers with an expansive invasive border were setoff clearly from TAFs obtained for the study cases, but TAFs of control cases with an infiltrative invasive border and mucinous carcinomas extended well into the range of TAFs recorded for regressing tumors. Locoregional recurrence (N = 10) was significantly associated with perineural tumor infiltration and capsule transgressing lymph node metastasis/tumor deposits but not with the degree of tumor regression. Overall survival was better for patients with major regressions (≤20th percentile by morphometry, or Dworak regression grade (DRG) 4/5), although statistical significance was not reached.

CONCLUSIONS

Morphometry of tumor regression is feasible and explains why conventional regression grading is so difficult to perform. Assessment of tumor regression, by subjective grading or morphometry, does not appear to convey major prognostic information, at least not substantially beyond histopathological tumor staging. This observation discourages expending too much effort on developing this aspect of the pathomorphological workup of the resection specimens.

Prognostic value of tumor shrinkage versus fragmentation following radiochemotherapy and surgery for rectal cancer

Most patients with rectal cancer receive neoadjuvant radiochemotherapy (RCT), causing a variable decrease in tumor mass. We evaluated the prognostic impact of pathologic parameters reflecting tumor response to RCT, either directly or indirectly. Seventy-six rectal cancer patients receiving neoadjuvant RCT between 2006 and 2009 were included. We studied the association between disease-free survival (DFS) and the "classical" clinicopathologic features as well as tumor deposits, circumferential resection margin (CRM), Dworak regression grade, and tumor and nodal downstaging. Patients with tumor downstaging had a longer DFS (p = 0.05), indicating a more favorable prognosis when regression was accompanied by a decrease in tumor infiltrative depth, referred to as tumor shrinkage. Moreover, tumor downstaging was significantly associated with larger CRM and nodal downstaging (p = 0.02), suggesting that shrinkage of the primary tumor was associated with a decreased nodal tumor load. Higher Dworak grade did not correlate with tumor downstaging, nor with higher CRM or prolonged DFS. This implies that tumor mass decrease was sometimes due to fragmentation rather than shrinkage of the primary tumor. Lastly, the presence of tumor deposits was clearly associated with reduced DFS (p = 0.01). Assessment of tumor shrinkage after RCT via tumor downstaging and CRM is a good way of predicting DFS in rectal cancer, and shrinkage of the primary tumor is associated with a decreased nodal tumor load. Assessing regression based on the amount of tumor in relation to stromal fibrosis does not accurately discern tumor fragmentation from tumor shrinkage, which is most likely the reason why Dworak grade had less prognostic relevance.

American Joint Committee on Cancer and College of American Pathologists regression grade: a new prognostic factor in rectal cancer

BACKGROUND

The American Joint Committee on Cancer and the College of American Pathologists provide guidelines for reporting pathologic response to neoadjuvant treatment of rectal cancer. The clinical relevance of these tumor regression grading guidelines is undefined.

OBJECTIVE

This study evaluates the prognostic significance of the American Joint Committee on Cancer/College of American Pathologists regression grading.

DESIGN

This is a retrospective cohort study based on data from a prospectively maintained colorectal cancer database. The cohorts were defined by American Joint Committee on Cancer/College of American Pathologists tumor regression grade.

SETTING

This study was performed at a single tertiary referral center.

PATIENTS

Five hundred thirty-eight patients with primary rectal adenocarcinoma who underwent neoadjuvant therapy between 1992 and 2012 were identified.

MAIN OUTCOME MEASURES

The primary outcome measures were overall and disease-free survival, cancer-specific mortality, and cumulative recurrence rate.

RESULTS

Five hundred thirty-eight patients were included, 105 of whom (19.5%) were American Joint Committee on Cancer/College of American Pathologists grade 0, 153 patients (28.4%) were grade 1, 181 patients (33.6%) were grade 2, and 99 (18.4%) were grade 3. Kaplan-Meier analysis revealed that American Joint Committee on Cancer/College of American Pathologists grade was associated with significant differences in overall survival (p < 0.001), disease-free survival (p < 0.001), and cumulative recurrence (p < 0.001). No local recurrences were observed in American Joint Committee on Cancer/College of American Pathologists grade 0 patients. Five-year overall survival rates were 89%, 74%, 63%, and 40% (p < 0.001); 5-year disease-free survival rates were 85%, 64%, 54%, and 33% (p < 0.001); and 5-year recurrence rates were 7%, 18%, 25%, and 33% (p <0.001) for American Joint Committee on Cancer/College of American Pathologists grades 0, 1, 2, and 3. After adjusting for significant covariates, including pathologic stage, American Joint Committee on Cancer/College of American Pathologists grade remained an independent predictor of overall survival (p < 0.001), disease-free survival (p < 0.001), and cumulative recurrence (p < 0.001) in Cox regression analyses.

LIMITATIONS

This was a retrospective study. There was a low local recurrence rate in our population, limiting the sensitivity of recurrence analyses.

CONCLUSIONS

This is the first study to delineate American Joint Committee on Cancer/College of American Pathologists regression grade as an independent oncologic prognostic factor. This information can be used in discussions with patients who have rectal cancer.

Comparison of tumor regression grade systems for locally advanced rectal cancer after multimodality treatment

BACKGROUND

Tumor regression grade (TRG) is a measure of histopathological response of rectal cancer to neoadjuvant chemoradiation and is associated with outcomes. Several TRG systems are used: Mandard (5,3-tier), Dowrak/Rödel (5,3-tier), Memorial Sloan Kettering Cancer Center (MSKCC), and American Joint Committee on Cancer (AJCC) Cancer Staging. A single measure of rectal cancer response would assist in comparing results across institutions, and in designing future rectal cancer studies. In this study, the predictive accuracies of the various published classification schemes are compared.

METHODS

Review of a prospective database identified 563 patients with locally advanced rectal cancer (T3/4 and/or N1) treated between 1998 and 2007 with long-course chemoradiation and total mesorectal excision. TRG was determined by measuring proportion of tumor mass replaced by fibrosis. Patients were classified into TRG schemes, which were compared by analyzing association with recurrence and survival using concordance index. Probabilities of recurrence-free survival were estimated using the Kaplan-Meier method. All statistical tests were two-sided.

RESULTS

All TRG systems were predictive of recurrence. Concordance indices of the three-tier Mandard, three-tier Dowrak/Rödel, three-tier MSKCC, and four-tier AJCC systems were: 0.665, 0.653, 0.683, and 0.694, respectively (higher number = better prediction). The AJCC system more accurately predicted recurrence than the three-tier Mandard (P = .002) or Dowrak/Rödel (P = .006) and had a higher concordance index than MSKCC, although this did not reach statistical significance (P = .068).

CONCLUSION

When classifying rectal cancer response to chemoradiation, the AJCC Staging Manual (7(th) edition) system is most accurate and should be adopted as the standard.

Pathological prognostic factors in locally advanced rectal carcinoma after neoadjuvant radiochemotherapy: analysis of 113 cases

AIMS

Neoadjuvant radiochemotherapy (RCT) followed by surgical resection is the treatment for locally advanced mid-rectal or low rectal cancer. The aim of this study was to evaluate postoperative histological prognostic factors in a series of surgical specimens after neoadjuvant RCT.

METHODS AND RESULTS

One hundred and thirteen patients were included. Macroscopic and microscopic examinations were performed according to CAP recommendations, with additional criteria such as tumour budding, the presence of calcifications, and response to neoadjuvant therapy assessed according to Modified Rectal Cancer Regression Grade (m-RCRG). The 3-year disease-free survival (DFS) was 67.6%. In univariate analysis, ypTN stage, tumour budding, circumferential margin, invaded margin and vascular and perineural invasion were prognostic factors. In multivariate analysis, the presence of calcifications (P = 0.04) and an involved circumferential margin (P = 0.03) were the only independent factors for worse DFS. mRCRG was not correlated with DFS. Among the 50 m-RCRG1 tumours, DFS was better in ypT0 patients than in other ypT stages (P = 0.003).

CONCLUSIONS

The presence of calcifications in the tumour bed is described for the first time as a prognostic factor in rectal cancer. The prognostic value of budding was demonstrated in this study after neoadjuvant RCT. ypT stage appears to be a more reliable predictor of oncological outcome than histological tumour regression grade, which needs to be standardized for better reproducibility.

Integrated ¹⁸F-FDG PET/perfusion CT for the monitoring of neoadjuvant chemoradiotherapy in rectal carcinoma: correlation with histopathology

PURPOSE

The aim of this study was to prospectively monitor changes in the flow-metabolic phenotype (ΔFMP) of rectal carcinoma (RC) after neoadjuvant chemoradiotherapy (CRT) and to evaluate whether ΔFMP of RC correlate with histopathological prognostic factors including response to CRT.

METHODS

Sixteen patients with RC (12 men, mean age 60.7 ± 12.8 years) underwent integrated (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/perfusion CT (PET/PCT), followed by neoadjuvant CRT and surgery. In 13 patients, PET/PCT was repeated after CRT. Perfusion [blood flow (BF), blood volume (BV), mean transit time (MTT)] and metabolic [maximum and mean standardized uptake values (SUVmax, SUVmean)] parameters as well as the FMP (BF × SUVmax) were determined before and after CRT by two independent readers and correlated to histopathological prognostic factors of RC (microvessel density, necrosis index, regression index, vascular invasion) derived from resected specimens. The diagnostic performance of ΔFMP for prediction of treatment response was determined.

RESULTS

FMP significantly decreased after CRT (p < 0.001), exploiting higher changes after CRT as compared to changes of perfusion and metabolic parameters alone. Before CRT, no significant correlations were found between integrated PET/PCT and any of the histopathological parameters (all p > 0.05). After CRT, BV and SUVmax correlated positively with the necrosis index (r = 0.67/0.70), SUVmax with the invasion of blood vessels (r = 0.62) and ΔFMP with the regression index (r = 0.88; all p < 0.05). ΔFMP showed high accuracy for prediction of histopathological response to CRT (AUC 0.955, 95 % confidence interval 0.833-1.000, p < 0.01) using a cut-off value of -75%.

CONCLUSION

In RC, ΔFMP derived from integrated (18)F-FDG PET/PCT is useful for monitoring the effects of neoadjuvant CRT and allows prediction of histopathological response to CRT.

Predicting the pathologic response of locally advanced rectal cancer to neoadjuvant concurrent chemoradiation using enzyme-linked immunosorbent assays (ELISAs) for biomarkers

PURPOSE

To investigate the role of biomarkers including serum tissue inhibitor of metalloproteinases-1 (TIMP-1), urokinase plasminogen activator receptor, vascular endothelial growth factor, and epidermal growth factor receptor in predicting pathologic response to neoadjuvant chemoradiation (NACRT) for rectal cancer.

METHODS

Between 2007 and 2009, 50 clinical TNM stage II or III patients were analyzed in this prospective study. Pre- and post-NACRT serum levels of biomarkers were assessed using ELISAs. The primary and secondary endpoints were pathologic complete response (pCR) and Mandard regression grade (MRG).

RESULTS

The pCR was reported in 5 patients (10.0%). According to the MRG, fifteen patients (30.0%) were divided into group A (Grade I-II), the others in group B (Grade III-V). On univariate analysis, post-NACRT TIMP-1 showed notable significance with pCR (P = 0.092) and significant correlation with MRG group A (P = 0.003). Post-NACRT TIMP-1 ≤ 204.5 ng/mL as cut-off value by ROC curve was associated with more pCR and MRG group A patients (P = 0.016 and 0.002). Interval between NACRT and surgery was related to pCR with approached trend levels of significance (P = 0.05) and to MRG group A significantly on univariate analysis of clinical factors (P = 0.031). On multivariate analysis, post-NACRT TIMP-1 was not significantly related to pCR (P = 0.187), while it was significantly associated with MRG (P = 0.009). Among clinical responders, post-NACRT TIMP-1 level ≤ 204.5 ng/mL was significantly associated with pCR (P = 0.021) and MRG group A (P = 0.003).

CONCLUSIONS

Post-NACRT serum TIMP-1 could be used as a predictive marker of pathologic response to NACRT in rectal cancer, even in patients with clinical response.

The prognostic value of tumour regression grade following neoadjuvant chemoradiation therapy for rectal cancer

AIM

To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative.

METHOD

One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection.

RESULTS

Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively).

CONCLUSION

Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.

Tumor regression grades: can they influence rectal cancer therapy decision tree?

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 significance of partial tumor regression after preoperative chemoradiotherapy for rectal cancer: a meta-analysis

BACKGROUND

Complete tumor regression after preoperative chemoradiotherapy for rectal cancer has been associated with better disease-free and overall survival. The survival experience for patients with partial tumor regression is less clear.

OBJECTIVE

The aim of this meta-analysis was to evaluate the prognostic significance of partial response after preoperative chemotherapy on disease-free survival in rectal cancer patients.

DATA SOURCES

Relevant studies were identified by a search of MEDLINE and EMBASE databases with no restrictions to October 31, 2012.

STUDY SELECTION

We included long-course radiotherapy that reported the association between degree of tumor regression and disease-free survival of rectal cancer.

INTERVENTIONS

Direct, indirect, and graph methods were used to extract HRs.

MAIN OUTCOME MEASURES

Study-specific HRs on the disease-free survival were pooled using a random-effects model. Eleven articles in total were selected. Analysis was performed first among the 6 studies that separated partial response from the complete response and later among all 11 of the studies.

RESULTS

Pooled HR was 0.49 (95% CI, 0.28-0.85) for the 6 studies that compared partial response with poor response. It was 0.41 (95% CI, 0.25-0.67) when all 11 of the studies were analyzed together.

LIMITATIONS

The studies were limited by not being prospective, randomized trials, and the tumor regression grades were not uniform.

CONCLUSIONS

Partial tumor response is associated with a 50% improvement in disease-free survival and should be considered as a favorable prognostic factor.

Radiotherapy response in microsatellite instability related rectal cancer

Preoperative radiotherapy may improve the resectability and subsequent local control of rectal cancers. However, the extent of radiation induced regression in these tumours varies widely between individuals. To date no reliable predictive marker of radiation sensitivity in rectal cancer has been identified. At the cellular level, radiation injury initiates a complex molecular network of DNA damage response (DDR) pathways that leads to cell cycle arrest, attempts at re-constituting the damaged DNA and should this fail, then apoptosis. This review presents the details which suggest the roles of DNA mismatch repair proteins, the lack of which define a distinct subset of colorectal cancers with microsatellite instability (MSI), in the DDR pathways. Hence routine assessment of the MSI status in rectal cancers may potentially serve as a predictor of radiotherapy response, thereby improving patient stratification in the administration of this otherwise toxic treatment.

Partial pathologic response and nodal status as most significant prognostic factors for advanced rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

This study evaluated the impact of tumor regression grading (TRG) and other pathologic variates in a cohort of rectal carcinoma patients treated with neoadjuvant chemoradiotherapy (CRT). The value of a grading less than pCR for predicting survival is unknown. Tumor budding has not been systematically studied in rectal cancer after neoadjuvant therapy.

METHODS

Pathologic risk factors for survival were evaluated on surgical specimens of 237 patients with stages I, II, and III rectal cancer treated between 1996 and 2006. All patients underwent preoperative CRT followed by surgical resection 6-8 weeks later. TRG, tumor grade, budding, venous invasion, radial margin, and nodal status were evaluated. The prognostic value of TRG categories was calculated with Cox regression models and validated with resampling methods.

RESULTS

TRG of <25% occurred in 61 (25.7%) and a complete response in 39 (16.4%) of the resected specimens. TRG of <25% was shown to be a statistically significant predictor for cancer-specific survival (CSS) and recurrence-free survival (RFS) compared to TRG ≥25% (P = 0.013). Tumor budding was present in 24 (10.1%) of the patients and was negatively associated with CSS (P = 0.013). Lymph node involvement was observed in 83 (35.0%) patients. TRG and nodal status (P < 0.001) were the most significant predictors associated with outcome.

CONCLUSION

Partial pathologic response ≥25% was a superior predictor compared to pCR for improved survival after preoperative CRT. CSS and RFS were adversely affected by the presence of lymph node metastases.

Hydroxymethylglutaryl-coenzyme a synthase 2 expression is associated with chemoradiotherapy responses in colorectal cancer

BACKGROUND

Preoperative chemoradiotherapy has become a standard treatment modality for locally advanced rectal cancer. Favorable long-term outcomes have been reported for patients with good responses to chemoradiotherapy. Therefore, predictive factors for chemoradiotherapy responses can be useful for their applicability to risk-adaptive therapy in patients with colorectal cancer.

OBJECTIVE

The aim of this study was to investigate whether hydroxymethylglutaryl-coenzyme A synthase 2, a key enzyme in ketogenesis, is associated with the responses of colorectal cancer cells to chemoradiotherapy.

DESIGN

Hydroxymethylglutaryl-coenzyme A synthase 2 was identified by a 2-dimensional gel electrophoresis -based proteome analysis. It was analyzed in 12 colorectal cancer cells for associations with radiation or 5-fluorouracil susceptibility by Western blotting, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium Bromide assay, and small interfering RNA transfection. Then, tumor tissues obtained from 45 patients with rectal cancer before chemoradiotherapy were analyzed by Western blotting for associations with chemoradiotherapy responses.

RESULTS

Expression of hydroxymethylglutaryl-coenzyme A synthase 2 was significantly correlated with intrinsic radiation resistance of 12 cancer cells. Hydroxymethylglutaryl-coenzyme A synthase 2 expression was significantly affected by treatment with either 5-fluorouracil or radiation depending on cell types. The artificial suppression of hydroxymethylglutaryl-coenzyme A synthase 2 did not result in the change of chemoradiation susceptibility in colorectal cancer cells. Nevertheless, in multivariate analyses, hydroxymethylglutaryl-coenzyme A synthase 2 expression in rectal cancer tissues was shown to be a significant predictive factor for chemoradiotherapy responses, as evaluated in terms of tumor regression grade and downstaging.

LIMITATIONS

Overall findings in vitro showed that the expression level of hydroxymethylglutaryl-coenzyme A synthase 2 was highly variable depending on colon cancer cell types, and it cannot directly affect on chemoradiotherapy responses. The molecular mechanism underpinning the association between hydroxymethylglutaryl-coenzyme A synthase expression and chemoradiotherapy responses needs to be elucidated through future research.

CONCLUSIONS

Hydroxymethylglutaryl-coenzyme A synthase 2 was associated with the effects of chemoradiotherapy on human colorectal cancer cells. Pretreatment levels of hydroxymethylglutaryl-coenzyme A synthase 2 in rectal cancer may be useful in predicting the responses to chemoradiotherapy.

Is step section necessary for determination of complete pathological response in rectal cancer patients treated with preoperative chemoradiotherapy?

AIMS

To assess the efficacy of the step section for determination of pathological complete response (pCR) in rectal cancer treated with preoperative chemoradiotherapy (CRT).

METHODS AND RESULTS

Of 709 patients with rectal cancer who received preoperative CRT, 88 were initially diagnosed as having pCR. These 88 patients were re-evaluated after two-level step sections of the entire tumour by using Dworak's regression grade. Additional serial step sections revealed residual tumour cells in seven of 88 patients (7.95%), all of whom were upgraded to regression grade 3 (near total regression) from regression grade 4 (total regression). Of these seven patients, one (14.3%) showed tumour recurrence, compared with 11 of 81 (13.6%) patients with a final regression grade of 4. Neither recurrence rate nor disease-free survival rate differed significantly between these two groups (P > 0.5). Calcification was significantly more frequent in grade 3 than in grade four patients (71.4% versus 32.1%; P = 0.037), and acellular mucin pools were associated with better disease-free survival (P = 0.022).

CONCLUSIONS

Stratifying patient outcome by final regression grade after step section did not yield different outcomes in patients with initial pCR. If residual tumour cells are not identified on initial meticulous examination, further processing of step sections is not necessary.

Usefulness of perfusion CT to assess response to neoadjuvant combined chemoradiotherapy in patients with locally advanced rectal cancer

RATIONALE AND OBJECTIVES

To prospectively evaluate perfusion computed tomography (CT) for assessment of changes in tumor vascularity after chemoradiation therapy (CRT) in locally advanced rectal cancer and to analyze the correlation between baseline perfusion parameters and tumor response.

MATERIALS AND METHODS

Twenty patients with rectal cancer underwent baseline perfusion CT before CRT, and in 11 an examination after CRT was also performed. For each tumor, blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) were quantified. The Mann-Whitney U test compared baseline perfusion parameters of responders and nonresponders and pre- and post-CRT measurements were compared by the Wilcoxon signed-rank test (P < .05 statistically significant for both tests).

RESULTS

Baseline BF was significantly lower (P = .013) and MTT was significantly higher (P = .006) in responders. Both were able to discriminate responders from nonresponders with a sensitivity of 80% and 100% and a specificity of 73.3% and 86.7%, respectively, for BF and MTT. Baseline BV and PS were not significantly different in responders and nonresponders. Perfusion parameters changed significantly in post-CRT scans compared to baseline: BF (P = .003), BV (P = .003), and PS (P = .008) decreased, whereas MTT increased (P = .006).

CONCLUSION

Baseline BF and MTT can discriminate patients with a favorable response from those that fail to respond to CRT, potentially selecting high-risk patients with resistant tumors that may benefit from an aggressive preoperative treatment approach.

Hepatic colorectal cancer metastases showing a distinctive pattern of pathological response after metronomic capecitabine and bevacizumab

A 48-year-old man was referred to our hospital with the diagnosis of colon cancer with multiple hepatic metastases. After right hemicolectomy, the rapid progression of liver disease was treated with metronomic capecitabine and bevacizumab according to a study protocol. A gradual regression of metastatic lesions was observed during a 9-month treatment period. After conversion of liver disease to resectability, the histological examination disclosed the complete necrosis of all lesions, with the exception of small neoplastic foci inside a single nodule. The comparison of this type of histological findings with the classic sclero-hyaline pathological response, as well as its importance as indicator of response to antiangiogenic treatment, is discussed.

Genomic alterations in rectal tumors and response to neoadjuvant chemoradiotherapy: an exploratory study

Background

Neoadjuvant chemoradiotherapy is the treatment of choice in advanced rectal cancer, even though there are many patients who will not benefit from it. There are still no effective methods for predicting which patients will respond or not. The present study aimed to define the genomic profile of rectal tumors and to identify alterations that are predictive of response in order to optimize therapeutic strategies.

Methods

Forty-eight candidates for neoadjuvant chemoradiotherapy were recruited and their pretherapy biopsies analyzed by array Comparative Genomic Hybridization (aCGH). Pathologic response was evaluated by tumor regression grade.

Results

Both Hidden Markov Model and Smoothing approaches identified similar alterations, with a prevalence of DNA gains. Non responsive patients had a different alteration profile from responsive ones, with a higher number of genome changes mainly located on 2q21, 3q29, 7p22-21, 7q21, 7q36, 8q23-24, 10p14-13, 13q12, 13q31-34, 16p13, 17p13-12 and 18q23 chromosomal regions.

Conclusions

This exploratory study suggests that an in depth characterization of chromosomal alterations by aCGH would provide useful predictive information on response to neoadjuvant chemoradiotherapy and could help to optimize therapy in rectal cancer patients.

The data discussed in this study are available on the NCBI Gene Expression Omnibus [GEO: GSE25885].

Histopathological regression grading versus staging of rectal cancer following radiotherapy

AIMS

To compare histological grading of rectal cancer radiotherapy response with pathological staging as a prognostic indicator.

METHODS

Histological tumour regression was five tier graded in 102 rectal cancer patients treated with preoperative radiotherapy [short course (n = 34), long course (n = 68)]. Differences between these grades and between the two radiotherapy regimes were assessed. These variables, pTMN staging and others were correlated with relapse free survival at 3 years.

RESULTS

22 patients suffered disease recurrence and four died during a mean post-operative follow-up of 40.3 months. There were 52 good responders (tumour regression grades 1-3) and 50 poor responders (tumour regression grades 4-5). Regression was greater following the long course regime (p < 0.0001). Otherwise, there were no significant differences between the response groups and between the two regimes, including the number of lymph nodes found in the resected bowel. Only the pN status correlated with relapse free survival on multivariate analysis (p = 0.0004; HR = 4.26, 95%CI = 1.66-10.93 for pN2 versus pN0).

CONCLUSIONS

The number of lymph nodes found for staging was not influenced by either the extent of primary tumour regression or the type of radiotherapy. pN status, but not tumour regression grade, is a reliable predictor of survival.

A combined strategy of SAGE and quantitative PCR Provides a 13-gene signature that predicts preoperative chemoradiotherapy response and outcome in rectal cancer

PURPOSE

Preoperative chemoradiotherapy (CRT) is the treatment of choice for rectal cancer (RC), but half of the patients do not respond, suffer unnecessary toxicities, and surgery delays. We aimed to develop a model that could predict a clinically meaningful response to CRT by using formalin-fixed paraffin-embedded (FFPE) biopsies.

EXPERIMENTAL DESIGN

We first carried out an exploratory screening of candidate genes by using SAGE technology to evaluate dynamic changes in the RC transcriptome in selected refractory patients before and after CRT. Next, 53 genes (24 from SAGE and 29 from the literature) were analyzed by qPCR arrays in FFPE initial biopsies from 94 stage II/III RC patients who were preoperatively treated with CRT. Tumor response was defined by using Dworak's tumor regression grade (2-3-4 vs. 0-1). Multivariate Cox methods and stepwise algorithms were applied to generate an optimized predictor of response and outcome.

RESULTS

In the training cohort (57 patients), a 13-gene signature predicted tumor response with 86% accuracy, 87% sensitivity, and 82% specificity. In a testing cohort (37 patients), the model correctly classified 6 of 7 nonresponders, with an overall accuracy of 76%. A signature-based score identified patients with a higher risk of relapse in univariate (3-year disease-free survival 64% vs. 90%, P = 0.001) and multivariate analysis (HR = 4.35 95% CI: 1.2-15.75, P = 0.02), in which it remained the only statistically significant prognostic factor.

CONCLUSIONS

A basal 13-gene signature efficiently predicted CRT response and outcome. Multicentric validation by the GEMCAD collaborative group is currently ongoing. If confirmed, the predictor could be used to improve patient selection in RC studies.

Prognostic importance of Mandard tumour regression grade following pre-operative chemo/radiotherapy for locally advanced rectal cancer

PURPOSE

To assess the prognostic value of the Mandard tumour regression score (TRG) following pre-operative chemo/radiotherapy in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

The study involved 158 patients with locally advanced rectal cancer treated with pre-operative long course chemo/radiotherapy at Nottingham University Hospital between April 2001 and December 2008. Patients were treated with radiotherapy to a dose of 50 Gy in 25 fractions over 5 weeks with or without concurrent capecitabine chemotherapy at a dose of 1650 mg/m(2)/day. Surgery was normally performed after an interval of 6-10 weeks. The response to pre-operative treatment was carefully graded by a single pathologist using the five point Mandard score. The median follow-up was 40 months (range 3-90 months).

RESULTS

Of the 158 patients 14% were TRG1, 41% were TRG2, 31% were TRG3, 13% were TRG4 and 1% were TRG5. The groups were combined into TRG1, TRG2 and TRG3-5 to simplify further analysis. The Mandard score was clearly related to both disease-free (p < 0.001) and overall survival (p = 0.012). On multivariate analysis perineural invasion, nodal status, TRG and circumferential resection margin status were the most powerful predictors of disease-free survival.

CONCLUSIONS

The Mandard tumour regression score is an independent prognostic factor and predicts for long-term outcome following pre-operative chemo/radiotherapy in rectal cancer.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.

Tumour regression grading in patients with residual rectal cancer after preoperative chemoradiation

BACKGROUND AND PURPOSE

To explore the utility of tumour regression grading (TRG, the amount of residual tumour cells in relation to extension of fibrosis) after chemoradiation of rectal cancer.

MATERIALS AND METHODS

Of 131 patients who received preoperative chemoradiation in the frame of the randomized trial, pathological complete response (pCR, TRG0), good regression (TRG1), moderate regression (TRG2), and poor regression (TRG3) were recorded in 17%, 31%, 31%, and 22% of patients, respectively.

RESULTS

The rates of ypN-positive category for TRG0, TRG1, TRG2, and TRG3 groups were 5%, 23%, 45%, and 46%, respectively, p=0.001. When ypT-category and TRG were evaluated by the logistic regression analysis, only ypT-category remained significant for independent prediction of the risk for mesorectal nodal metastases, p=0.006. The 4-year (median follow-up) disease-free survival (DFS) for TRG0, TRG1, TRG2, and TRG3 groups were 91%, 67%, 54%, and 47%. When patients with persistent disease (TRG1 vs. TRG2 vs. TRG3) were analyzed separately, TRG had no prognostic value for DFS, p=0.402.

CONCLUSIONS

TRG in patients with residual cancer had no prognostic value for the incidence of nodal disease and for DFS. Our findings and literature data question the need for the inclusion of TRG assessment into a routine pathological report.

Complete pathological response in a patient with multiple liver metastases from colon cancer treated with Folfox-6 chemotherapy plus bevacizumab: a case report

The complete pathological response after primary chemotherapy could represent an important prognostic factor in patients affected by colorectal liver metastases. In recent studies, increasing complete pathological response seems to be correlated with longer overall survival periods and it is recognized as an important prognostic factor in patients treated with pre-operative chemotherapy. The correlation of radiological information on residual neoplastic disease after neoadjuvant treatment, obtained with CT and PET, has to be evaluated; in fact the complete disappearance of liver metastasis on radiological imaging does not always mean a complete disappearance of tumor tissue on histological examination; when it is documented with surgical procedures and confirmed by pathologist's examination, we can consider the complete pathological response. In recent years the addition of monoclonal antibodies to conventional chemotherapy may further increase the proportion of patients referred for surgery; bevacizumab before surgery has been shown to be feasible and safe, although concerns still exist regarding possible post-surgical and wound healing complications or bleeding. The limitation of the radiologic assessment of response as a surrogate for pathological response is even more relevant when antiangiogenic treatments are used. Excellent responses to bevacizumab-containing regimens do occur and referral to surgical oncology is a crucial step for documentation of complete pathological response.

Prognostic value of carcinoembryonic antigen level in rectal cancer treated with neoadjuvant chemoradiotherapy

BACKGROUND

The purpose of this study was to identify clinical and pathological parameters to improve prediction of disease-free survival (DFS) and overall survival (OS) in patients treated with neoadjuvant chemoradiotherapy for rectal cancer.

METHODS

Between July 1995 and May 2007, 148 patients with primary rectal adenocarcinoma received neoadjuvant chemoradiotherapy followed by mesorectal excision. Preoperative treatment included various protocols, UFT and leucovorin (28%) and oxaliplatin-based chemotherapy (72%). Clinical and pathological variables were evaluated in relation to patient outcomes.

RESULTS

Thirteen percent of patients achieved a complete pathologic response. No response or minimal response as defined by Dworak (Tumor Regression Grade 0/1) was observed in 30 patients (20%). At a median follow-up of 37 months, the 3-year DFS and OS were 64% and 83%, respectively. Pre-treatment serum carcinoembryonic antigen (CEA) level </= 2.5 ng/ml was associated with higher DFS (74 vs. 53%; p = 0.018), higher complete pathologic responses (21 vs. 9%; p = 0.05), and less recurrences (24 vs. 44%; p = 0.014).

CONCLUSION

The data suggest that a CEA level </= 2.5 ng/ml might be a predictor not only of tumor response, as has been suggested before, but also of DFS. This finding could be useful in the future to predict individual risk and to develop more aggressive or alternative strategies.

The correlation between tumour regression grade and lymph node status after chemoradiation in rectal cancer

OBJECTIVE

To determine the correlation between tumour response to preoperative RCTX and lymph node status, an established parameter of clinical outcome.

METHOD

After IRB approval, 86 consecutive rectal cancer patients who received preoperative RCTX were identified. Fifty seven were males. Mean age 62 years. Preoperative staging by ultrasound was available in 60 patients. Radiotherapy consisted of (40-60 g) and chemotherapy of 5-FU infusion (1500 mg/m(2) week), assessed using Dworak's system.

RESULTS

Tumour response according to Tumor regression grade (TRG) were: TRG 0: 8 (9.3%); TRG 1: 15 (17.4%); TRG 2: 14 (16.2%); TRG 3: 31 (36%); TRG 4: 18 (20%). Eighteen patients had tumour stage 0 (20.9%); while 8 (9.2%), 28 (32.1%), 30 (34.5%) and three had tumours stages 1, 2, 3 and 4 respectively. Evaluation of nodal status revealed no involvement in 65 patients (N0), and positive nodes in 21 (14 N1, 7 N2). Response to RCTX was significantly associated with node stage, hence individuals without node involvement (N0) had 66% of positive tumour response (TRG 4), while individuals with node metastasis had less response to RCTX (TRG 0, 1 and 2) 35% N1 and 14% for N2 (P = 0.007). Node status was independently associated to poor response to preoperative RCTX, even after adjusting for tumour stage, age and gender (OR 0.02, 95% CI 0.0009-0.67).

CONCLUSION

Tumour shrinkage by preoperative RCTX appears to correlate with lymph node metastasis suggesting that neoadjuvant RCTX may have a positive impact in overall patient survival.