Impact of tumor response on survival after radiochemotherapy in locally advanced rectal carcinoma. Am J Surg Pathol. 2010;34:562-568. [PMID: 20216380 DOI: 10.1097/pas.0b013e3181d438b0]

Prognostic analysis of rectal cancer patients after neoadjuvant chemoradiotherapy: different prognostic factors in patients with different TRGs

PURPOSE

The extent of tumor regression varies widely among locally advanced rectal cancer (LARC) patients who receive neoadjuvant chemoradiotherapy (NCRT) followed by total mesorectal excision (TME). The purpose of this retrospectively study is to assess prognostic factors in LARC patients with NCRT, and further to analyze survival outcomes in patients with different tumor regression grades (TRGs).

METHODS

This study includes LARC patients who underwent NCRT and TME at our institution. We retrospectively analyzed the clinicopathological characteristics and survival of all patients, and performed subgroup analysis for patients with different TRGs. Survival differences were compared using the Kaplan-Meier method and the log rank test. Additionally, a multiple Cox proportional hazard model was used to identify independent prognostic factors.

RESULTS

The study included 393 patients, with 21.1%, 26.5%, 45.5%, and 6.9% achieving TRG 0, TRG 1, TRG 2, and TRG 3, respectively. The overall survival (OS) rate and disease-free survival (DFS) rate for all patients were 89.4% and 70.7%, respectively. Patients who achieved TRG 0-3 had different 5-year OS rates (96.9%, 91.1%, 85.2%, and 68.8%, P = 0.001) and 5-year DFS rates (80.8%, 72.4%, 67.0%, 55.8%, P = 0.031), respectively. Multivariate analyses showed that the neoadjuvant rectal (NAR) score was an independent prognostic indicator for both overall survival (OS) (HR = 4.040, 95% CI = 1.792-9.111, P = 0.001) and disease-free survival (DFS) (HR = 1.971, 95% CI = 1.478-2.628, P ˂ 0.001). In the subgroup analyses, the NAR score was found to be associated with DFS in patients with TRG 1 and TRG 2. After conducting multivariate analysis, it was found that ypT stage was a significant predictor of DFS for TRG 1 patients (HR = 4.384, 95% CI = 1.721-11.168, P = 0.002). On the other hand, ypN stage was identified as the dominant prognostic indicator of DFS for TRG 2 patients (HR = 2.795, 95% CI = 1.535-5.091, P = 0.001). However, none of these characteristics was found to be correlated with survival in patients with TRG 0 or TRG 3.

CONCLUSION

NAR score, in particular, appears to be the most powerful prognostic factor. It is important to consider various prognostic predictors for patients with different TRGs.

Tumor regression and safe distance of distal margin after neoadjuvant therapy for rectal cancer

Neoadjuvant therapy has been widely employed in the treatment of rectal cancer, demonstrating its utility in reducing tumor volume, downstaging tumors, and improving patient prognosis. It has become the standard preoperative treatment modality for locally advanced rectal cancer. However, the efficacy of neoadjuvant therapy varies significantly among patients, with notable differences in tumor regression outcomes. In some cases, patients exhibit substantial tumor regression, even achieving pathological complete response. The assessment of tumor regression outcomes holds crucial significance for determining surgical approaches and establishing safe margins. Nonetheless, current research on tumor regression patterns remains limited, and there is considerable controversy surrounding the determination of a safe margin after neoadjuvant therapy. In light of these factors, this study aims to summarize the primary patterns of tumor regression observed following neoadjuvant therapy for rectal cancer, categorizing them into three types: tumor shrinkage, tumor fragmentation, and mucinous lake formation. Furthermore, a comparison will be made between gross and microscopic tumor regression, highlighting the asynchronous nature of regression in the two contexts. Additionally, this study will analyze the safety of non-surgical treatment in patients who achieve complete clinical response, elucidating the necessity of surgical intervention. Lastly, the study will investigate the optimal range for safe surgical resection margins and explore the concept of a safe margin distance post-neoadjuvant therapy.

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.

A prognostic nomogram for stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy followed by surgical resection

Background

The purpose of this study was to develop a large population-based nomogram incorporating the log odds of positive nodes (LODDS) for predicting the overall survival (OS) of stage II/III rectal cancer patients treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgical resection.

Methods

The Surveillance, Epidemiology, and End Results database was used to collect information on patients diagnosed with stage II/III rectal cancer between 2010 and 2015 and treated with NCRT followed by surgical resection. The Cox regression analyses were performed to determine the independent prognostic factors. In this study, LODDS was employed instead of American Joint Committee on Cancer (AJCC) 7th N stage to determine lymph node status. Then a nomogram integrating independent prognostic factors was developed to predict the 24-, 36-, and 60-month overall survival. The receiver operating characteristic (ROC) curves and calibration curves were used to validate the nomogram. Furthermore, patients were stratified into three risk groups (high-, middle-, and low-risk) based on the total points obtained from the nomogram. And Kaplan–Meier curves were plotted to compare the OS of the three groups.

Results

A total of 3829 patients were included in the study. Race, sex, age, marital status, T stage, tumor grade, tumor size, LODDS, CEA level, and postoperative chemotherapy were identified as independent prognostic factors, based on which the prognostic nomogram was developed. The area under curve values of the nomogram for the 24-, 36-, and 60-month OS in the training cohort were 0.736, 0.720, and 0.688, respectively; and 0.691, 0.696, and 0.694 in the validation cohort, respectively. In both the validation and training cohorts, the calibration curves showed a high degree of consistency between actual and nomogram-predicted survival rates. The Kaplan–Meier curves showed that the three risk groups had significant differences in overall survival (P < 0.001).

Conclusion

A large population-based nomogram incorporating LODDS was developed to assist in evaluating the prognosis of stage II/III rectal cancer patients treated with NCRT followed by surgical resection. The nomogram showed a satisfactorily discriminative and stable ability to predict the OS for those patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01710-z.

Impact of Body Composition During Neoadjuvant Chemoradiotherapy on Complications, Survival and Tumor Response in Patients With Locally Advanced Rectal Cancer

Background

To explore the impact of body composition before neoadjuvant chemoradiotherapy (pre-NCRT) and after neoadjuvant chemoradiotherapy (post-NCRT) on complications, survival, and tumor response in patients with locally advanced rectal cancer (LARC).

Methods

Patients with LARC who underwent radical surgery after NCRT between Ja 22nuary 2012 and March 2019 were studied. Body composition parameters, including skeletal muscle area (SMA), muscle density (MD), visceral fat area (VFA), total abdominal fat area (TAFA), and subcutaneous fat area (SFA), was identified at the third lumbar vertebra level on computed tomography (CT). The patients were divided into two groups based on the sex-specific quartile values of SMA, MD, VFA, TAFA, SFA, and body composition change. Patient characteristics, short- and long-term postoperative complications, survival, and tumor response were analyzed.

Results

A total of 122 eligible patients were enrolled. Body composition parameters, except MD, were strongly correlated with BMI (p < 0.001). Pre-NCRT low MD (p = 0.04) and TAFA loss (p = 0.02) were significantly correlated with short- and long-term ileus, respectively. Pre-NCRT low SMA was a significant prognostic factor for both disease-free survival (DFS) (HR 2.611, 95% CI 1.129–6.040, p = 0.025) and cancer-specific survival (CSS) (HR 3.124, 95% CI 1.030–9.472, p = 0.044) in the Cox regression multivariate analysis. Multivariate logistic regression analysis identified post-NCRT SFA (OR 3.425, 95% CI 1.392–8.427, p = 0.007) and SFA loss (OR 3.358, 95% CI 1.214–9.289, p = 0.02) as independent risk factors for tumor regression grade (TRG) and downstaging, respectively.

Conclusion

Pre-NCRT low MD and TAFA loss were related to a high incidence of short- and long-term ileus, respectively. Pre-NCRT low SMA was a significant prognostic factor for CSS and DFS. Post-NCRT SFA and SFA loss were independent risk factors for TRG and downstaging, respectively.

Oncological strategy following R1 sphincter-saving resection in low rectal cancer after chemoradiotherapy

AIM

Sphincter-saving resection (SSR) for low rectal cancer remains challenging due to the high risk of positive resection margin (R1). Long-term outcomes and the dedicated oncological strategy are not well established in this situation. The aim of this study was to define the more appropriate strategy according to the patterns of recurrence.

METHODS

Between 1994 and 2014, patients treated by SSR for low rectal cancer with preoperative chemoradiotherapy were included. Three types of recurrences were defined: local (LR), distant (DR) and mixed (MR). Recurrences and survival after R0 and R1 resection were analysed by Kaplan-Meier and compared with the log-rang test.

RESULTS

Among 394 patients receiving SSR, 42 (10.6%) had R1 resection. Independent factors of R1 resection were EMVI (OR2.24,95%IC1.10-4.53,p = 0.025) and no tumor downstaging (OR8.41,95%IC2.50-8.32,p = 0.001). Both 5-year disease free and overall survival, and 5-year distant and local recurrence, were significantly worse after R1 resection. The overall recurrence after R1 resection was 57% (24/42), 7% had LR, 36% DR and 14% MR. Time to DR was shorter than time to LR (11.1 vs. 34.3) months. In all cases of MR, DR occurred before LR (12.1 vs. 34.3) months, meaning that after R1 resection, the first concern was DR.

CONCLUSION

R1 resection after SSR for low rectal cancer reflects a more aggressive and systemic disease. Prognosis depends on DR in about 90% of cases, suggesting that pelvic control should not be the priority in the oncological strategy after R1. Adjuvant systemic chemotherapy ought to be preferred to salvage abdominoperineal resection.

The impact of sarcopenia on pathologic complete response following neoadjuvant chemoradiation in rectal cancer

PURPOSE

The role of sarcopenia in pathologic complete response (pCR) following neoadjuvant chemoradiotherapy (nCRT) in non-metastatic locally advanced rectal cancer is currently unknown. The present study investigates the association between sarcopenia and post-nCRT pCR.

METHODS

The data of patients operated on following nCRT between January 2013 and January 2020 were collected retrospectively. Sarcopenia was diagnosed based on the calculation of the skeletal muscle index (SMI) from computed tomography carried out at the time of the initial diagnosis. A statistical analysis was then conducted for predictors of pCR.

RESULTS

The study included 61 patients with an average age of 57.3 years, 28 of whom formed the non-sarcopenic group (NSG) and 33 the sarcopenic group (SG). Of the patients, 32.7% were at clinical stage 2, and 67.3% were at clinical stage 3. Pathologic data following a mesorectal excision revealed a pCR rate of 21.4% in the NSG compared with 3% in the SG, which was a statistically significant difference (p = 0.025). The TNM downstaging rate was higher in the NSG than in the SG, although the difference was not statistically significant (50% vs. 33.3%, p = 0.28). A univariate analysis revealed the factors affecting pCR to be non-sarcopenia (p = 0.025), age < 61 years (p = 0.004), interval to surgery ≥ 8 weeks (p = 0.029), and serum CEA < 2.5 ng/ml (p = 0.035).

CONCLUSION

Sarcopenia was found to be a negative marker of pCR following nCRT in non-metastatic locally advanced rectal cancer.

Evaluation and Comparison of Predictive Value of Tumor Regression Grades according to Mandard and Becker in Locally Advanced Gastric Adenocarcinoma

Purpose

Tumor regression grade (TRG) has been widely used in gastrointestinal carcinoma to assess pathological responses to neoadjuvant chemotherapy (NCT). There are various standards without a consensus, and it is still unclear which kind of system has better predictive value. This study aims to investigate and compare the predictive ability of the Mandard and Becker TRGs in patients with locally advanced gastric cancer.

Materials and Methods

A total of 290 patients with locally advanced gastric adenocarcinoma who underwent NCT and curative surgery were studied. Survival analysis for overall survival (OS) and disease-free survival (DFS) were based on the Kaplan-Meier method and Cox proportional hazards method. Predictive values of TRGs and models were assessed by time-dependent receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), nomogram, and calibration curve.

Results

In multivariable analysis, the Mandard TRG was associated with OS (hazard ratio [HR], 1.806; p=0.026) and DFS (HR, 1.792; p=0.017). The Becker TRG was also related to OS (HR, 1.880; p=0.014) and DFS (HR, 1.919; p=0.006). The Mandard and Becker TRG AUCs for 5-year survival were 0.72 and 0.71, respectively. The whole models showed an increased predictive value, with AUCs of 0.85 and 0.86, respectively. There was no significant difference between the two TRGs and two models.

Conclusion

TRG was an independent predictor for survival, and there was no significant difference between these two systems.

How to measure tumour response in rectal cancer? An explanation of discrepancies and suggestions for improvement

Various methods categorize tumour response after neoadjuvant therapy, including down-staging and tumour regression grading. Response categories allow comparison of different treatments within clinical trials and predict outcome. A reproducible response categorization could identify subgroups with high or low risk for the most appropriate subsequent treatments, like watch and wait. Lack of standardization and interpretation difficulties currently limit the usability of these approaches. In this review we describe these difficulties for the evaluation of chemoradiation in rectal cancer. An alternative approach of tumour response is based on patterns of residual disease, including fragmentation. We summarise the evidence behind this alternative method of response categorisation, which explains a number of very relevant clinical discrepancies. These issues include differences between downstaging and tumour regression, high local regrowth in advanced tumours during watchful waiting procedures, the importance of resection margins, the limited value of post-treatment biopsies and the relatively poor outcome of patients with a near complete pathological response. Recognition of these patterns of response can allow meaningful development of novel biomarkers in the future.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

Comparison of three-dimensional versus two-dimensional laparoscopic surgery for rectal cancer: a meta-analysis

PURPOSE

Three-dimensional (3D) vision technology has recently been validated for the improvement of surgical skills in a simulated setting. This study assessed the current evidence regarding the efficiency and potential advantages of 3D compared with two-dimensional (2D) laparoscopic rectal surgery for rectal cancer.

METHODS

We comprehensively searched PubMed, EMBASE and the Cochrane Library and performed a systematic review and cumulative meta-analysis of all randomized controlled trials (RCTs) and non-randomized controlled trials (nRCTs) assessing the two approaches.

RESULTS

Four trials including a total 331 cases were identified. The positive circumferential resection margins (CRMs) were significantly lower for the 3D group (P = 0.02). The operative time was significantly shorter in the 3D group than in the 2D group (P < 0.00001). There was less estimated blood loss (EBL) in the 3D group than in the 2D group (P = 0.02). Perioperative complication rates, conversion rate, harvested lymph nodes, first flatus, length of stay, pneumonia, wound infection, ileus, anastomotic fistula and urinary retention did not differ significantly between the two groups (P > 0.05).

CONCLUSIONS

In summary, 3D laparoscopic rectal surgery appears to have advantages over 2D laparoscopic rectal surgery in terms of positive CRM and operation time; however, it is not better than 2D laparoscopic rectal surgery in terms of the conversion rate and postoperative complications.

Type of preoperative therapy and stage-specific survival after surgery for rectal cancer: a nationwide population-based cohort study

Preoperative chemoradiation therapy (CRT) may induce downstaging in rectal cancer (RC). Short-course radiation therapy (SC-RT) with immediate surgery does not cause substantial downstaging. However, the TNM classification adds the “y” prefix in both groups to indicate possible treatment effects. We aim to compare stage-specific survival in these patients. RC patients treated with surgery only, preoperative SC-RT followed by surgery within 10 days, or preoperative CRT, and diagnosed between 2008 and 2014 were included in this population-based study. Clinicopathological and outcome characteristics were analyzed. The study included 11,925 patients. Large discrepancies existed between clinical and pathological stages after surgery only. Surgery-only patients were older with more comorbidities compared with SC-RT and CRT and had worse 5-year survival (64%, 76%, and 74%, respectively; p < 0.001). Five-year survival for stage I was similar after CRT and SC-RT (85% vs. 85%; p = 0.167) and comparable between CRT-treated patients with stage I and those reaching a pathological complete response (pCR; 85% vs. 89%; p = 0.113). CRT was independently associated with worse overall survival compared with SC-RT for stage II (HR 1.57 [95%CI 1.27–1.95]; p < 0.001) and stage III (HR 1.43 [95%CI 1.23–1.70]; p < 0.001). Stage I disease after CRT has an excellent prognosis, comparable with pCR and with same-stage SC-RT-treated patients without regression. Stage II or III after CRT has worse prognosis than after SC-RT with immediate surgery. TNM should take the impact of preoperative therapy type on stage-specific survival into account. In addition, clinical stage was a poor predictor of pathological stage.

Prognostic Value of Clinical vs Pathologic Stage in Rectal Cancer Patients Receiving Neoadjuvant Therapy

Background

Neoadjuvant chemoradiation is currently standard of care in stage II-III rectal cancer, resulting in tumor downstaging for patients with treatment-responsive disease. However, the prognosis of the downstaged patient remains controversial. This work critically analyzes the relative contribution of pre- and post-therapy staging to the anticipated survival of downstaged patients.

Methods

The National Cancer Database (NCDB) was queried for patients with rectal cancer treated with transabdominal resection between 2004 and 2014. Stage II-III patients downstaged with neoadjuvant radiation were compared with stage I patients treated with definitive resection alone. Patients with positive surgical margins were excluded. Overall survival was evaluated using both Kaplan-Meier analyses and Cox proportional hazards models. All statistical tests were two-sided.

Results

A total of 44 320 patients were eligible for analysis. Survival was equivalent for patients presenting with cT1N0 disease undergoing resection (mean survival = 113.0 months, 95% confidence interval [CI] = 110.8 to 115.3 months) compared with those downstaged to pT1N0 from both cT3N0 (mean survival = 114.9 months, 95% CI = 110.4 to 119.3 months, P = .12) and cT3N1 disease (mean survival = 115.4 months, 95% CI = 110.1 to 120.7 months, P = .22). Survival statistically significantly improved in patients downstaged to pT2N0 from cT3N0 disease (mean survival = 109.0 months, 95% CI = 106.7 to 111.2 months, P < .001) and cT3N1 (mean survival = 112.8 months, 95% CI = 110.0 to 115.7 months, P < .001), compared with cT2N0 patients undergoing resection alone (mean survival = 100.0 months, 95% CI = 97.5 to 102.5 months). Multiple survival analysis confirmed that final pathologic stage dictated long-term outcomes in patients undergoing neoadjuvant radiation (hazard ratio [HR] of pT2 = 1.24, 95% CI = 1.10 to 1.41; HR of pT3 = 1.81, 95% CI = 1.61 to 2.05; HR of pT4 = 2.72, 95% CI = 2.28 to 3.25, all P ≤ .001 vs pT1; HR of pN1 = 1.50, 95% CI = 1.41 to 1.59; HR of pN2 = 2.17, 95% CI = 2.00 to 2.35, both P < .001 vs pN0); while clinical stage at presentation had little to no predictive value (HR of cT2 = 0.81, 95% CI = 0.69 to 0.95, P = .008; HR of cT3 = 0.83, 95% CI = 0.72 to 0.96, P = .009; HR of cT4 = 1.02, 95% CI = 0.85 to 1.21, P = .87 vs cT1; HR of cN1 = 0.96, 95% CI = 0.91 to 1.02, P = .19; HR of cN2 = 0.96, 95% CI = 0.86 to 1.08, P = .48 vs cN0).

Conclusions

Survival in patients with rectal cancer undergoing neoadjuvant radiation is driven by post-therapy pathologic stage, regardless of pretherapy clinical stage. These data will further inform prognostic discussions with patients.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy?

Background

We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).

Methods

Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.

Results

The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).

Conclusion

CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

Tumor regression grade as a clinically useful outcome predictor in patients with rectal cancer after preoperative chemoradiotherapy

BACKGROUND

The prognostic role of tumor regression grade is not clear. This study evaluated the prognostic significance of tumor regression grade in patients with rectal cancer after preoperative chemoradiotherapy.

METHODS

A total of 639 patients with confirmed rectal cancer who had undergone preoperative chemoradiotherapy and radical resection during the period October 2002 through December 2011 were included in this study. The tumor regression grade was graded: TRG0 (complete response), TRG1 (moderate), TRG2 (minimal), and TRG3 (poor). The prognostic significance of tumor regression grade was evaluated.

RESULTS

With a median follow-up of 56.7 months, the rates of 5-year overall survival, disease-free survival, and local recurrence-free survival among the TRG groups differed significantly (all P < .001). For patients with TRG0, TRG1, and TRG2-3, disease-free survivals were different between the ypStage (P < .001, P < .001, and P = .043). Multivariate analysis revealed findings to substantiate that the tumor regression grade represents a valuable and independent prognostic factor for long-term, disease-free survival (P = .041). Independent predictors of TRG2-3 consisted of lymphovascular invasion, tumor budding, and the pretreatment serum level of carcinoembryonic antigen in multivariate regression analysis. Clinical risk grouping, using 3 predictors for TRG2-3 was different (P < .001).

CONCLUSION

The tumor regression grade may represent a useful prognostic variable to better individualize the prognosis and potentially further therapy for each rectal cancer patient who underwent chemoradiotherapy.

Applicability of American Joint Committee on Cancer and College of American Pathologists Regression Grading System in Rectal Cancer

BACKGROUND

Different tumor grading systems have been proposed to predict the association between tumor response and clinical outcome after preoperative chemoradiotherapy in patients with rectal cancer. The American Joint Committee on Cancer and College of American Pathologists regression grading system was recommended as the standard tumor regression grading system for rectal adenocarcinoma.

OBJECTIVE

This study evaluated the clinical applicability of the American Joint Committee on Cancer and College of American Pathologists regression grading system in neoadjuvant-treated patients with rectal cancer.

DESIGN

This is a retrospective cohort study based on clinical data from a prospectively maintained colorectal cancer database.

SETTINGS

This study was performed at a single tertiary referral center.

PATIENTS

A total of 144 patients with primary locally advanced mid-to-low rectal adenocarcinoma who underwent preoperative long-course chemoradiotherapy and total mesorectal excision between 2003 and 2012 were included.

MAIN OUTCOMES MEASURES

The primary outcome measures were the 5-year overall survival rate, the relapse-free survival rate, the cancer-specific survival rate, and cumulative recurrence rates.

RESULTS

Of the 144 patients, 16 (11%) were diagnosed as American Joint Committee on Cancer and College of American Pathologists regression grade 0, 43 patients (30%) as grade 1, 61 patients (42%) as grade 2, and 25 patients (17%) as grade 3.After a median follow-up time of 83 months (range, 3 to 147 mo), 5-year survival estimates for grades 0, 1, 2, and 3, were 93%, 77%, 81%, and 54% for overall survival (p = 0.006); 93%, 82%, 75%, and 55% for relapse-free survival (p = 0.03); and 100%, 86%, 89%, and 63% for cancer-specific survival (p = 0.006). The multivariate Cox regression analyses confirmed the American Joint Committee on Cancer and College of American Pathologists regression grading system as a prognostic factor for overall (p = 0.04), relapse-free (p = 0.02), and cancer-specific survival (p = 0.04).

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

Our study findings confirm the clinical relevance and applicability of the American Joint Committee on Cancer and College of American Pathologists regression grade system as a predictive factor for patients with rectal cancer. See Video Abstract at http://links.lww.com/DCR/A320.

Oncological results of extended resection for locally advanced rectal cancer: the value of postirradiation MRI in predicting local recurrence

AIM

The primary purpose of this study was to analyse the overall survival and local recurrence rate after extended resection of locally advanced rectal cancer. The second aim was to determine the ability of the response to radiological irradiation to predict R0 resection.

METHOD

A retrospective study was performed of 94 consecutive patients with locally advanced rectal cancer operated on at the Helsinki University Hospital, Helsinki, Finland between 2005 and 2013. Data were collected from patient records. All patients were treated with an en bloc resection. Sixty-two patients received preoperative long-term chemoradiotherapy.

RESULTS

The 30-day mortality was 3.2%. Local recurrence occurred in 10 (10.6%) patients. The cumulative 1-, 3- and 5-year overall survival to each year was 89.4%, 68.3% and 51.8%. The most important prognostic factor for both local recurrence (P = 0.006) and survival (P = 0.003) was an R0 resection. A poor or no response seen on posttreatment MRI predicted local recurrence (P = 0.045) and decreased disease-free survival in patients treated curatively (P = 0.052). The histological tumour regression grade was not associated with local recurrence or survival.

CONCLUSION

Multivisceral resection offers a 5-year survival of over 50% and local control of advanced rectal cancer in nearly 90% of carefully selected patients.

Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales

AIM

To define good and poor regression using pathology and magnetic resonance imaging (MRI) regression scales after neo-adjuvant chemotherapy for rectal cancer.

METHODS

A systematic review was performed on all studies up to December 2015, without language restriction, that were identified from MEDLINE, Cochrane Controlled Trials Register (1960-2015), and EMBASE (1991-2015). Searches were performed of article bibliographies and conference abstracts. MeSH and text words used included “tumour regression”, “mrTRG”, “poor response” and “colorectal cancers”. Clinical studies using either MRI or histopathological tumour regression grade (TRG) scales to define good and poor responders were included in relation to outcomes [local recurrence (LR), distant recurrence (DR), disease-free survival (DFS), and overall survival (OS)]. There was no age restriction or stage of cancer restriction for patient inclusion. Data were extracted by two authors working independently and using pre-defined outcome measures.

RESULTS

Quantitative data (prevalence) were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. Qualitative data (LR, DR, DFS and OS) were presented as ranges. The overall proportion of poor responders after neo-adjuvant chemo-radiotherapy (CRT) was 37.7% (95%CI: 30.1-45.8). There were 19 different reported histopathological scales and one MRI regression scale (mrTRG). Clinical studies used nine and six histopathological scales for poor and good responders, respectively. All studies using MRI to define good and poor response used one scale. The most common histopathological definition for good response was the Mandard grades 1 and 2 or Dworak grades 3 and 4; Mandard 3, 4 and 5 and Dworak 0, 1 and 2 were used for poor response. For histopathological grades, the 5-year outcomes for poor responders were LR 3.4%-4.3%, DR 14.3%-20.3%, DFS 61.7%-68.1% and OS 60.7-69.1. Good pathological response 5-year outcomes were LR 0%-1.8%, DR 0%-11.6%, DFS 78.4%-86.7%, and OS 77.4%-88.2%. A poor response on MRI (mrTRG 4,5) resulted in 5-year LR 4%-29%, DR 9%, DFS 31%-59% and OS 27%-68%. The 5-year outcomes with a good response on MRI (mrTRG 1,2 and 3) were LR 1%-14%, DR 3%, DFS 64%-83% and OS 72%-90%.

CONCLUSION

For histopathology regression assessment, Mandard 1, 2/Dworak 3, 4 should be used for good response and Mandard 3, 4, 5/Dworak 0, 1, 2 for poor response. MRI indicates good and poor response by mrTRG1-3 and mrTRG4-5, respectively.

What Is the Ideal Tumor Regression Grading System in Rectal Cancer Patients after Preoperative Chemoradiotherapy?

Purpose

Tumor regression grade (TRG) is predictive of therapeutic response in rectal cancer patients after chemoradiotherapy (CRT) followed by curative resection. However, various TRG systems have been suggested, with subjective categorization, resulting in interobserver variability. This study compared the prognostic validity of four different TRG systems in order to identify the most ideal TRG system.

Materials and Methods

This study included 933 patients who underwent preoperative CRT and curative resection. Primary tumors alone were graded according to the American Joint Committee on Cancer (AJCC), Dworak, and Ryan TRG systems, and both primary tumors and regional lymph nodes were graded according to a modified Dworak TRG system. The ability of each TRG system to predict recurrence-free survival (RFS) and overall survival (OS) was analyzed using chi-square and C statistics.

Results

All four TRG systems were significantly predictive of both RFS and OS (p < 0.001 each), however none was a better predictor of prognosis than ypStage. Among the four TRGs, the mDworak TRG system was a better predictor of RFS and OS than the AJCC, Dworak, and Ryan TRG systems, and both the chi-square and C statistics were higher for the former, although the differences were not statistically significant. The combination of ypStage and the modified Dworak TRG better predicted RFS and OS than ypStage alone.

Conclusion

The modified Dworak TRG system for evaluation of entire tumors including regional lymph nodes is a better predictor of survival than current TRG systems for evaluation of the primary tumor alone.

Pathologic Assessment of Rectal Carcinoma after Neoadjuvant Radio(chemo)therapy: Prognostic Implications

Neoadjuvant radio(chemo)therapy is increasingly used in rectal cancer and induces a number of morphologic changes that affect prognostication after curative surgery, thereby creating new challenges for surgical pathologists, particularly in evaluating morphologic changes and tumour response to preoperative treatment. Surgical pathologists play an important role in determining the many facets of rectal carcinoma patient care after neoadjuvant treatment. These range from proper handling of macroscopic specimens to accurate microscopic evaluation of pathological features associated with patients' prognosis. This review presents the well-established pathological prognostic indicators and discusses challenging features in order to provide both surgical pathologists and treating physicians with a checklist that is useful in a neoadjuvant setting.

Predictive and prognostic biomarkers for neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Locally advanced rectal cancer is regularly treated with trimodality therapy consisting of neoadjuvant chemoradiation, surgery and adjuvant chemotherapy. There is a need for biomarkers to assess treatment response, and aid in stratification of patient risk to adapt and personalise components of the therapy. Currently, pathological stage and tumour regression grade are used to assess response. Experimental markers include proteins involved in cell proliferation, apoptosis, angiogenesis, the epithelial to mesenchymal transition and microsatellite instability. As yet, no single marker is sufficiently robust to have clinical utility. Microarrays that screen a tumour for multiple promising candidate markers, gene expression and microRNA profiling will likely have higher yield and it is expected that a combination or panel of markers would prove most useful. Moving forward, utilising serial samples of circulating tumour cells or circulating nucleic acids can potentially allow us to demonstrate tumour heterogeneity, document mutational changes and subsequently measure treatment response.

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.

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.

Pathology is a necessary and informative tool in oncology clinical trials

Clinical trials are essential for the improvement of cancer care. The complexity of modern cancer care and research require careful design, for which input from all disciplines is necessary. Pathologists should play a key role in the design and execution of modern cancer trials, with special attention to the eligibility, stratification and evaluation of response to therapy. In the current review all these aspects are discussed, with examples from colorectal cancer trials. We describe critical issues in biomarker evaluation and development and emphasize the importance of the role of the pathologist in quality control of cancer treatment.

MRI predictive factors for tumor response in rectal cancer following neoadjuvant chemoradiation therapy--implications for induction chemotherapy?

PURPOSE

Clinical and magnetic resonance imaging (MRI) characteristics at baseline and following chemoradiation therapy (CRT) most strongly associated with histopathologic response were investigated and survival outcomes evaluated in accordance with imaging and pathological response.

METHODS AND MATERIALS

Responders were defined as mrT3c/d-4 downstaged to ypT0-2 on pathology or low at risk mrT2 downstaged to ypT1 or T0. Multivariate logistic regression of baseline and posttreatment MRI: T, N, extramural venous invasion (EMVI), circumferential resection margin, craniocaudal length <5 cm, and MRI tumor height ≤5 cm were used to identify independent predictor(s) for response. An association between induction chemotherapy and EMVI status was analyzed. Survival outcomes for pathologic and MRI responders and nonresponders were analyzed.

RESULTS

Two hundred eighty-one patients were eligible; 114 (41%) patients were pathology responders. Baseline MRI negative EMVI (odds ratio 2.94, P=.007), tumor height ≤5 cm (OR 1.96, P=.02), and mrEMVI status change (positive to negative) following CRT (OR 3.09, P<.001) were the only predictors for response. There was a strong association detected between induction chemotherapy and ymrEMVI status change after CRT (OR 9.0, P<.003). ymrT0-2 gave a positive predictive value of 80% and OR of 9.1 for ypT0-2. ymrN stage accuracy of ypN stage was 75%. Three-year disease-free survival for pathology and MRI responders were similar at 80% and 79% and significantly better than poor responders.

CONCLUSIONS

Tumor height and mrEMVI status are more important than baseline size and stage of the tumor as predictors of response to CRT. Both MRI- and pathologic-defined responders have significantly improved survival. "Good response" to CRT in locally advanced rectal cancer with ypT0-2 carries significantly better 3-year overall survival and disease-free survival. Use of induction chemotherapy for improving mrEMVI status and knowledge of MRI predictive factors could be taken into account in the pursuit of individualized neoadjuvant treatments for patients with rectal cancer.

Comparison between preoperative and postoperative concurrent chemoradiotherapy for rectal cancer: an institutional analysis

PURPOSE

To evaluate the treatment outcomes of preoperative versus postoperative concurrent chemoradiotherapy (CRT) on locally advanced rectal cancer.

MATERIALS AND METHODS

Medical data of 114 patients with locally advanced rectal cancer treated with CRT preoperatively (54 patients) or postoperatively (60 patients) from June 2003 to April 2011 was analyzed retrospectively. 5-Fluorouracil (5-FU) or a precursor of 5-FU-based concurrent CRT (median, 50.4 Gy) and total mesorectal excision were conducted for all patients. The median follow-up duration was 43 months (range, 16 to 118 months). The primary end point was disease-free survival (DFS). The secondary end points were overall survival (OS), locoregional control, toxicity, and sphincter preservation rate.

RESULTS

The 5-year DFS rate was 72.1% and 48.6% for the preoperative and postoperative CRT group, respectively (p = 0.05, the univariate analysis; p = 0.10, the multivariate analysis). The 5-year OS rate was not significantly different between the groups (76.2% vs. 69.0%, p = 0.23). The 5-year locoregional control rate was 85.2% and 84.7% for the preoperative and postoperative CRT groups (p = 0.98). The sphincter preservation rate of low-lying tumor showed significant difference between both groups (58.1% vs. 25.0%, p = 0.02). Pathologic tumor and nodal down-classification occurred after the preoperative CRT (53.7% and 77.8%, both p < 0.001). Acute and chronic toxicities were not significantly different between both groups (p = 0.10 and p = 0.62, respectively).

CONCLUSION

The results confirm that preoperative CRT can be advantageous for improving down-classification rate and the sphincter preservation rate of low-lying tumor in 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.

Assessment of Histopathological Response in Gastric and Gastro-Oesophageal Junction Adenocarcinoma following Neoadjuvant Chemotherapy: Which Scoring System to Use?

Background. The standard of care for patients with operable gastric and gastro-oesophageal junction (GOJ) tumours involves neoadjuvant chemotherapy. This improves survival and reduces risk of tumour recurrence following surgery. The various grading criteria published to assess histological response to neoadjuvant treatments have never been compared in terms of their reproducibility and ability to predict survival. Methods. A study was carried out of 66 patients with gastric and GOJ (types II and III) adenocarcinoma treated with neoadjuvant chemotherapy according to the MAGIC protocol. Histology slides were reviewed independently by two histopathologists using three published grading systems (Mandard, Japanese, and Becker). Histological, demographic, and survival data were collected. The kappa statistic was used to assess interobserver reproducibility. Results. Three (5%) patients had a complete pathological response. There was reasonable interobserver agreement for the grading systems: κ-scores = 0.44 (Mandard), 0.28 (Japanese), and 0.51 (Becker). Only Mandard and Becker scores provided prognostic information: 5-year overall survival rates of 100% for complete or near complete responders versus 35% for nonresponders () for both. Positive lymph nodes () and resection margins () were associated with poor survival. Conclusion. Becker’s score is most reproducible for the evaluation of histological response. Furthermore, lymph node and resection margins status provides prognostic information.

A observational study of the efficacy and safety of capecitabine versus bolus infusional 5-fluorouracil in pre-operative chemoradiotherapy for locally advanced rectal cancer

BACKGROUND AND OBJECTIVES

This study is to evaluate the safety and efficacy of preoperative radiotherapy (RT) combined with bolus infusional 5-fluorouracil (5-FU) or oral capecitabine in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Seventy-four patients were retrospectively analyzed. Twenty-seven patients were treated with 5-FU (350 mg/m(2) i.v. bolus) and leucovorin (20 mg/m(2) i.v. bolus) for 5 days/week during week 1 and 5 of RT. Forty-seven patients were treated with capecitabine (850 mg/m(2), twice daily for 5 days/week). Both groups received the same RT course (45-50.4 Gy/25 fractions, 5 days/week, for 5 weeks). Patients underwent surgery in 6 weeks after completion of the chemoradiotherapy. Data of the observational study were collected.

RESULTS

Grade 3 or 4 toxicities occurred in 40.7% (5-FU) and 19.1% (capecitabine) of the patients (P = 0.044). Six patients in the 5-FU group (22.2%) and six patients in the capecitabine group (14%) achieved complete response. Primary tumor (T) downstaging were achieved in 51.9% (5-FU) and 69.8% (capecitabine) of the patients. The pathological ypT0-2 stage was 40.7% (5-FU) and 67.4% (capecitabine) (P = 0.028).

CONCLUSIONS

In consideration of the better ypT0-2 downstaging rate, less severe toxicities, and no need for indwelling intravenous device on oral capecitabine regimen, the administration of oral capecitabine with RT may be a more favorable option in the neoadjuvant treatment for LARC.

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.

Primary staging and response assessment postchemoradiotherapy in rectal cancer

SUMMARY Initial assessment of newly diagnosed patients with rectal cancer includes clinical examination, colonoscopy, pelvic MRI and CT scan of the thorax, abdomen and pelvis. Radiological staging can objectively evaluate both surgical and biological prognostic features of rectal cancer. MRI has emerged to be the most useful preoperative prognostic staging tool and it can predict the risk of tumor involvement of surgical circumferential resection margin. An agreed definition of favorable tumor response to chemoradiotherapy is controversial. The importance of detecting and assessing good versus poor responders to chemoradiotherapy is of increasing relevance. MRI has been found to be useful in assessing tumor response postchemoradiotherapy, especially the assessment of potential circumferential resection margin and magnetic resonance tumor regression grade. These imaging markers predict survival outcomes for good and poor responders and provide an opportunity for clinicians to offer additional neoadjuvant and adjuvant treatments to reduce local or distance failure for the poor responders.

[Locally advanced rectal cancer management: which role for the pathologist in 2011?]

Locally advanced rectal cancers mainly correspond to lieberkünhien adenocarcinomas and are defined by T3-T4 lesions with or without regional metastatic lymph nodes. Such tumors benefit from neoadjuvant treatment combining chemotherapy and radiotherapy, followed by surgery with total mesorectum excision. Such a strategy can decrease the rate of local relapse and lead to an easier complementary surgery. The pathologist plays an important role in the management of locally advanced rectal cancer. Indeed, he is involved in the gross examination of the mesorectum excision quality and in the exhaustive sampling of the most informative areas. He also has to perform a precise histopathological analysis, including the determination of the circumferential margin or clearance and the evaluation of tumor regression. All these parameters are major prognostic factors which have to be clearly included in the pathology report. Moreover, the next challenge for the pathologist will be to determine and validate new prognostic and predictive markers, notably by using pre-therapeutic biopsies. The goal of this mini-review is to emphasize the pathologist's role in the different steps of the management of locally advanced rectal cancers and to underline its implication in the determination of potential biomarkers of aggressiveness and response.

The prognostic value of grade of regression and oncocytic change in rectal adenocarcinoma treated with neo-adjuvant chemoradiotherapy

BACKGROUND

Pathological staging and regression grading may affect the clinical outcome in rectal carcinoma patients treated with neoadjuvant chemoradiation (NACRT). Oncocytic change (OC) has also been described in the residual tumor. This study assesses the correlation of degree of pathological response and OC with clinical outcome.

METHODS

Seventy-five cases of rectal adenocarcinoma undergoing NACRT followed by surgery were retrospectively analyzed for preoperative and post-operative staging, degree of tumor response to NACRT using the Dworak Regression score (DR) and Tumor Regression Grading (TRG) systems, as well as the proportion of cells showing OC. These parameters were correlated with overall survival (OS) and disease-free survival (DFS).

RESULTS

Significant correlation was found between post-operative T and N stage and OS (P = 0.005 and 0.002, respectively); and post-operative and preoperative T stage with DFS (P = 0.002 and 0.02, respectively). Grouping patients by TRG scores (TRG1-3 vs TRG4-5) also proved to be a significant independent prognosticator for DFS (P < 0.001). The DR score groups and OC (<35% vs. >35%) were not statistically significant predictors of clinical outcome.

CONCLUSIONS

Post-NACRT T and N staging and the TRG system are important prognostic indicators. The presence and extent of OC needs to be better understood and further investigated.

Neoadjuvant vs adjuvant pelvic radiotherapy for locally advanced rectal cancer: Which is superior?

The treatment of locally advanced rectal cancer including timing and dosage of radiotherapy, degree of sphincter preservation with neoadjuvant radiotherapy, and short and long term effects of radiotherapy are controversial topics. The MEDLINE, Cochrane Library databases, and meeting proceedings from the American Society of Clinical Oncology, were searched for reports of randomized controlled trials and meta-analyses comparing neoadjuvant and adjuvant radiotherapy with surgery to surgery alone for rectal cancer. Neoadjuvant radiotherapy shows superior results in terms of local control compared to adjuvant radiotherapy. Neither adjuvant or neoadjuvant radiotherapy impacts overall survival. Short course versus long course neoadjuvant radiotherapy remains controversial. There is insufficient data to conclude that neoadjuvant therapy improves rates of sphincter preserving surgery. Radiation significantly impacts anorectal and sexual function and includes both acute and long term toxicity. Data demonstrate that neoadjuvant radiation causes less toxicity compared to adjuvant radiotherapy, and specifically short course neoadjuvant radiation results in less toxicity than long course neoadjuvant radiation. Neoadjuvant radiotherapy is the preferred modality for administering radiation in locally advanced rectal cancer. There are significant side effects from radiation, including anorectal and sexual dysfunction, which may be less with short course neoadjuvant radiation.