Preoperative chemoradiotherapy and total mesorectal excision surgery for locally advanced rectal cancer: correlation with rectal cancer regression grade

Stage IV Rectal Cancer and Timing of Surgical Approach

Liver metastases are seen in at least 60% of patients with colorectal cancer at some point during the course of their disease. The management of both primary and liver disease is uniquely challenging in rectal cancer due to competing treatments and complex sequence of treatments depending on the clinical presentation of disease. Recently, several novel concepts are shaping new treatment paradigms, including changes in timing, sequence, and duration of therapies combined with potential deescalation of treatment components. Overall, the treatment of this clinical scenario mandates multidisciplinary evaluation and personalization of care; however, there is still considerable debate regarding the timing of liver metastasectomy in the context of the overall treatment plan. Herein, we will discuss the current literature on management of rectal cancer with synchronous liver metastasis, current treatment approaches with respect to chemotherapy, and role of hepatic artery infusion therapy.

Predictive and Prognostic Value of Oncogene Mutations and Microsatellite Instability in Locally-Advanced Rectal Cancer Treated with Neoadjuvant Radiation-Based Therapy: A Systematic Review and Meta-Analysis

Markers of pathological complete response (pCR) to preoperative radiation-based therapy in locally advanced rectal cancer (LARC) are strongly needed. This meta-analysis aimed at elucidating the predictive/prognostic role of tumor markers in LARC. We systematically reviewed the impact of RAS, TP53, BRAF, PIK3CA, and SMAD4 mutations and MSI status on response (pCR, downstaging) and prognosis (risk of recurrence, survival) in LARC according to PRISMA guidelines and the PICO model. PubMed, Cochrane Library, and Web of Science Core Collection were systematically searched to identify relevant studies published before October 2022. KRAS mutations were significantly associated with the risk of not achieving pCR after preoperative treatment (summary OR = 1.80, 95% CI: 1.23-2.64). This association was even more significant in patients not receiving cetuximab (summary OR = 2.17, 95% CI: 1.41-3.33) than in patients receiving cetuximab (summary OR = 0.89, 95% CI: 0.39-20.05). MSI status was not associated with pCR (summary OR = 0.80, 95% CI: 0.41-1.57). No effect of KRAS mutation or MSI status on downstaging was detected. Meta-analysis of survival outcomes was not possible due to the large heterogeneity among studies in endpoint assessment. The minimum number of eligible studies to assess the predictive/prognostic role of TP53, BRAF, PIK3CA, and SMAD4 mutations was not reached. KRAS mutation, but not MSI status, proved to be a detrimental marker for response to preoperative radiation-based therapy in LARC. Translating this finding into the clinic could improve the management of LARC patients. More data are needed to clarify the clinical impact of TP53, BRAF, PIK3CA, and SMAD4 mutations.

Neoadjuvant Pelvic Radiotherapy in the Management of Rectal Cancer with Synchronous Liver Metastases: Is It Worth It?

BACKGROUND

The use of neoadjuvant pelvic radiotherapy was a major advance in oncologic care for locally advanced rectal cancer in the twentieth century. The extrapolation of the care of locally advanced rectal cancer to the management of rectal cancer with treatable liver metastases is controversial. The aim of this review is to examine the available data on the role of pelvic radiotherapy and chemoradiation in the setting of treatable metastatic liver disease.

METHODS

A systematic search of MEDLINE was performed to report the landmark randomized controlled trials between 1993 and 2021.

RESULTS

Attaining liver clearance and total mesorectal excision with R0 margin remains the mainstay of cure. There is uncertainty regarding the sequencing of treatment. The literature lacks randomized clinical trials comparing the rectal first, liver first, interval strategy, and simultaneous surgical approaches. A multidisciplinary discussion regarding the utility of radiotherapy is emphasized to achieve the goals of treatment. Short-course radiotherapy has proved comparable disease-control outcomes to long-course chemoradiation with a significantly improved cost-performance. The implementation of short-course radiotherapy in the interval strategy and simultaneous surgical approach is promising. Neoadjuvant pelvic radiotherapy can be omitted in patients with metastatic rectal cancer if adequate margin clearance is achievable.

CONCLUSION

The use of radiotherapy in metastatic rectal cancer is popular but is based on limited data. Treatment should be tailored to the local extent of rectal cancer and priority of liver metastasis management. The optimal treatment strategy in patients with rectal cancer and synchronous liver metastatic disease needs to be studied in randomized trials.

Neoadjuvant Capecitabine and Oxaliplatin Before Concurrent Capecitabine and Radiation in Locally Advanced Rectal Cancers: Experience of a Cancer Hospital in Pakistan

To report the toxicity and pathologic response rates after adding neoadjuvant capecitabine and oxaliplatin (CAPOX) followed by concurrent radiation and capecitabine (CAPRT) and surgery in patients with locally advanced rectal cancer.

Evolution and Current Status of the Multidisciplinary Management of Locally Advanced Rectal Cancer

The management of locally advanced rectal cancer has grown in both complexity and quality since the first proctectomy. What once was a malignancy with a fairly consistent treatment algorithm for decades, a recent paradigm shift in the care of these patients has led to a more personalized, multidisciplinary approach with variations in timing, sequence, duration, and potential exclusion of multimodality therapies. This review summarizes the most important evidence behind these developing overarching concepts to provide a context for this paradigm shift.

Intratumoral HLA-DR-/CD33+/CD11b+ Myeloid-Derived Suppressor Cells Predict Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

Capecitabine-based neoadjuvant chemoradiation therapy (nCRT) is currently the mainstay of treatment for locally advanced rectal cancer (LARC), prior to surgical tumor removal. While response to this treatment is partial, it carries significant risk of side effects. As of today, there is no accepted model to predict tumor response, and allow for patient stratification. The level of circulating Myeloid-derived suppressor cells (MDSCs), a subpopulation of early myeloid cells (EMCs), has been shown to correlate with prognosis and response to therapy in advanced colon cancer, but their role in LARC is not clear. We sought to study the effect of intratumoral and circulating levels of different EMCs subpopulations including MDSCs on response to nCRT. We analyzed tumor, normal mucosa, and peripheral blood samples from 25 LARC patients for their different EMCs subpopulation before and after nCRT, and correlated them with degree of pathologic response, as determined postoperatively. In addition, we compared LARC patient to 10 healthy donors and 6 metastatic patients. CD33⁺HLA-DR⁻CD16⁻CD11b⁺EMCs in the circulation of LARC patients were found to inhibit T-cell activation. Furthermore, elevated levels of CD33⁺HLA-DR⁻ myeloid cells were found in the tumor relative to normal mucosa, but not in the circulation when compared to healthy subjects. Moreover, intratumoral, but not circulating levels of MDSCs correlated with clinical stage and response to therapy in patients treated with nCRT, with high levels of MDSCs significantly predicting poor response to nCRT. Importantly, therapy by itself, had significant differential effects on MDSC levels, leading to increased circulating MDSCs, concomitantly with decreasing intratumoral MDSCs. Our results suggest that high levels of intratumoral, but not circulating MDSCs may confer drug resistance due to immunomodulatory effects, and serve as a biomarker for patient stratification and decision-making prior to nCRT.

Are there predictors that can determine neoadjuvant treatment responses in rectal cancer?

BACKGROUND/AIMS

This study aimed to determine a predictive bioindicator that would detect the treatment response of patients diagnosed with rectal cancer and treated with neoadjuvant chemoradiotherapy (nCRT).

MATERIALS AND METHODS

The data collected from 37 patients receiving nCRT were retrospectively evaluated. The p53 score and gene instability in MLH1 and MSH2, which are among the DNA mismatch repair (MMR) genes, were evaluated using immunohistochemical methods. The neutrophils-leukocytes ratio (NLR), carcinoembryonic antigen (CEA), and carbohydrate antigen (CA) 19-9 values were obtained as hematological parameters from computer records. The pathologic analysis of the therapy response after nCRT was classified according to the modified grading system by Ryan et al. Results: The changes in the NLR, CEA, and CA19-9 values before and after treatment were statistically significant (p<0.001 and p=0.005). A near significant effect of the decrease of the CEA value in the 5th week after treatment was detected on the pathological response score (p=0.075). The p53 mutation score in those patients with any residue was higher than the total response. Overall, 89.2% of the patients exhibited MMR positivity (stability), and 10.8% of the cases with MRM negativity (instability) had a macroscopic residue. Cases with pathological total response were MRM positive.

CONCLUSION

Consequently, in most of the patients treated with nCRT, the treatment caused tumor and nodal remission. In the prediction of this therapy response, hematological and genetic parameters, such as NLR, P53, MLH1, and MSH2, play a predictive role.

Rectal cancer sub-clones respond differentially to neoadjuvant therapy

Treatment of locally advanced rectal cancer includes chemotherapy, radiation, and surgery but patient responses to neoadjuvant treatment are variable. We have shown that rectal tumors are comprised of multiple genetically distinct sub-clones. Unique sub-clones within tumors may harbor mutations which contribute to inter-patient variation in response to neoadjuvant chemoradiotherapy (nCRT). Analysis of the influence of nCRT on the extent and nature of intra-tumoral genetic heterogeneity in rectal cancer may provide insights into mechanisms of resistance.

Locally advanced rectal cancer patients underwent pre-treatment biopsies. At the time of surgery, tissue from the treated tumor was obtained and analyzed. Pre- and post-treatment specimens were subjected to whole exome and confirmatory deep sequencing for somatic mutations. Copy number variation was assessed using OncoScan SNP arrays. Genomic data were analyzed using PyClone to identify sub-clonal tumor population following nCRT. Alterations that persisted or were enriched in the post-treatment tumor specimen following nCRT were defined for each patient.

Thirty-two samples were obtained from ten patients. PyClone identified 2 to 10 genetic sub-clones per tumor. Substantial changes in the proportions of individual sub-clones in pre- versus post-treatment tumor material were found in all patients. Resistant sub-clones recurrently contained mutations in TP53, APC, ABCA13, MUC16, and THSD4. Recurrent copy number variation was observed across multiple chromosome regions after nCRT. Pathway analysis including variant alleles and copy number changes associated with resistant sub-clones revealed significantly altered pathways, especially those linked to the APC and TP53 genes, which were the two most frequently mutated genes.

Intra-tumoral heterogeneity is evident in pre-treatment rectal cancer. Following treatment, sub-clonal populations are selectively modified and enrichment of a subset of pre-treatment sub-clones is seen. Further studies are needed to define recurrent alterations at diagnosis that may contribute to resistance to nCRT.

The Krüppel-like factor (KLF5) as a predictive biomarker in preoperative chemoradiation therapy for rectal cancer

Purpose

Preoperative chemoradiation therapy (CRT) has become the standard treatment for patients with locally advanced rectal cancer, 15%–30% of patients still progress while being treated with CRT. The aim of this study was to identify as important biomarker of poor response and evaluate the mechanism associated with CRT resistance.

Methods

This study included 60 human colon tumour pre-irradiation specimens. Expressions of epidermal growth factor receptor (EGFR), p53, Krüppel-like factor 5 (KLF5), C-ern, Ki67 were assessed and correlated with tumor regression grades and complete remission. We added in vitro study with biomarker which has been identified as important biomarker of poor response to evaluate the mechanism associated with CRT resistance.

Results

Pathologic complete remission (pCR) was achieved by 9 patients (18%). EGFR and KLF5 were significantly associated with pCR (P = 0.048, P = 0.023, respectfully). And multivariate analysis showed high KLF5 intensity was worse factor for pCR (P = 0.012). In vitro study, radiation or chemotherapy therapy stabilized KLF5 protein levels in a time- and dose-depended manner in HCT116 and Caco-2 cells. KLF5 overexpression in HCT116 stable cell line showed significantly better cell viability by increasing cyclinD1 and b-catenin compared to control cells in MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, suggesting that KLF5 mediates cell survival.

Conclusion

KLF5 was significantly associated with the presence of KRAS mutations, and KLF5 was an independent poor response predictor of CRT in rectal cancer. Our study is pilot study and more research will be needed in the future.

Image-guided surgery in cancer: A strategy to reduce incidence of positive surgical margins

Primary treatment for many solid cancers includes surgical excision or radiation therapy, with or without the use of adjuvant therapy. This can include the addition of radiation and chemotherapy after primary surgical therapy, or the addition of chemotherapy and salvage surgery to primary radiation therapy. Both primary therapies, surgery and radiation, require precise anatomic localization of tumor. If tumor is not targeted adequately with initial treatment, disease recurrence may ensue, and if targeting is too broad, unnecessary morbidity may occur to nearby structures or remaining normal tissue. Fluorescence imaging using intraoperative contrast agents is a rapidly growing field for improving visualization in cancer surgery to facilitate resection in order to obtain negative margins. There are multiple strategies for tumor visualization based on antibodies against surface markers or ligands for receptors preferentially expressed in cancer. In this article, we review the incidence and clinical implications of positive surgical margins for some of the most common solid tumors. Within this context, we present the ongoing clinical and preclinical studies focused on the use of intraoperative contrast agents to improve surgical margins. This article is categorized under: Laboratory Methods and Technologies > Imaging.

The potential predictive value of DEK expression for neoadjuvant chemoradiotherapy response in locally advanced rectal cancer

BACKGROUND

Limited data are available regarding the ability of biomarkers to predict complete pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer. Complete response translates to better patient survival. DEK is a transcription factor involved not only in development and progression of different types of cancer, but is also associated with treatment response. This study aims to analyze the role of DEK in complete pathological response following chemoradiotherapy for locally advanced rectal cancer.

METHODS

Pre-treated tumour samples from 74 locally advanced rectal-cancer patients who received chemoradiation therapy prior to total mesorectal excision were recruited for construction of a tissue microarray. DEK immunoreactivity from all samples was quantified by immunohistochemistry. Then, association between positive stained tumour cells and pathologic response to neoadjuvant treatment was measured to determine optimal predictive power.

RESULTS

DEK expression was limited to tumour cells located in the rectum. Interestingly, high percentage of tumour cells with DEK positiveness was statistically associated with complete pathological response to neoadjuvant treatment based on radiotherapy and fluoropyrimidine-based chemotherapy and a marked trend toward significance between DEK positiveness and absence of treatment toxicity. Further analysis revealed an association between DEK and the pro-apoptotic factor P38 in the pre-treated rectal cancer biopsies.

CONCLUSIONS

These data suggest DEK as a potential biomarker of complete pathological response to treatment in locally advanced rectal cancer.

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.

Quantitative intravoxel incoherent motion parameters derived from whole-tumor volume for assessing pathological complete response to neoadjuvant chemotherapy in locally advanced rectal cancer

BACKGROUND

Many locally advanced rectal cancer (LARC) patients can benefit from neoadjuvant chemotherapy (NACT), with some achieving a pathological complete response (pCR). However, there is limited research reporting on the value of intravoxel incoherent motion (IVIM) in monitoring pCR in patients with LARC.

PURPOSE

To identify whether IVIM parameters derived from whole-tumor volume (WTV) before and after NACT could accurately assess pCR in patients with LARC.

STUDY TYPE

Prospective patient control study.

POPULATION

Fifty-one patients with LARC before and after NACT, prior to surgery.

FIELD STRENGTH/SEQUENCE

IVIM-diffusion imaging at 3T.

ASSESSMENT

Apparent diffusion coefficient (ADC), slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion-related diffusion fraction (f) values were obtained on diffusion-weighted magnetic resonance images (DW-MRI) using WTV methods and calculated using a biexponential model before and after NACT.

STATISTICAL TESTS

DWI-derived ADC and IVIM-derived parameters and their percentage changes (ΔADC%, ΔD%, ΔD*%, and Δf%) were compared using independent-samples t-test and Mann-Whitney U-test between the pCR and non-pCR groups. The diagnostic performance of IVIM parameters and their percentage changes were evaluated using receiver operating characteristic curves.

RESULTS

Compared with the non-pCR group, the pCR group exhibited significantly lower pre-ADC_mean (P = 0.003) and pre-D values (P = 0.024), and significantly higher post-f (P = 0.002), ΔADC_mean % (P = 0.002), ΔD% (P = 0.001), and Δf% values (P = 0.017). Receiver operating characteristic curves showed that the pre-D value had the best specificity (95.12%) and accuracy (86.27%) in predicting the pCR status, and ΔD% had the highest area under the curve (0.832) in assessing the pCR response to NACT.

DATA CONCLUSIONS

The IVIM-derived D value is a promising tool in predicting the pCR status before therapy. The percentage changes in D values after therapy may help assess the pCR status prior to surgery.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017.

Development and validation of a preoperative prediction model for colorectal cancer T-staging based on MDCT images and clinical information

Objectives

This study aimed to establish and evaluate the efficacy of a prediction model for colorectal cancer T-staging.

Results

T-staging was positively correlated with the level of carcinoembryonic antigen (CEA), expression of carbohydrate antigen 19-9 (CA19-9), wall deformity, blurred outer edges, fat infiltration, infiltration into the surrounding tissue, tumor size and wall thickness. Age, location, enhancement rate and enhancement homogeneity were negatively correlated with T-staging. The predictive results of the model were consistent with the pathological gold standard, and the kappa value was 0.805. The total accuracy of staging improved from 51.04% to 86.98% with the proposed model.

Materials and Methods

The clinical, imaging and pathological data of 611 patients with colorectal cancer (419 patients in the training group and 192 patients in the validation group) were collected. A spearman correlation analysis was used to validate the relationship among these factors and pathological T-staging. A prediction model was trained with the random forest algorithm. T staging of the patients in the validation group was predicted by both prediction model and traditional method. The consistency, accuracy, sensitivity, specificity and area under the curve (AUC) were used to compare the efficacy of the two methods.

Conclusions

The newly established comprehensive model can improve the predictive efficiency of preoperative colorectal cancer T-staging.

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.

Significance of Anemia in Outcomes After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Approximately one quarter of patients receiving neoadjuvant chemoradiotherapy (NCRT) for locally advanced rectal cancer will be anemic at presentation. The outcomes of these anemic patients have historically been less favorable. We assessed the potential of anemia to act as an independent biomarker for a poor prognosis in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

We performed a retrospective, observational study of consecutive patients with locally advanced rectal adenocarcinoma who underwent NCRT from 2004 to 2009 at 3 English National Health Service trusts. The main outcomes were Rectal Cancer Regression Grade, mortality rate, and disease-free survival. These were compared between the anemic and nonanemic patients.

RESULTS

A total of 273 patients were included. Of these patients, 63 (23%) had a hemoglobin level of < 120 g/L (anemic) at presentation. The Rectal Cancer Regression Grades were higher (less regression) in the anemic patients than in the nonanemic patients (χ² = 10.14; P = .006). A subgroup analysis stratified by disease stage at presentation demonstrated less tumor regression in anemic patients with Dukes stage C disease (Dukes stage B, χ² = 4.31, P = .12; Dukes stage C, χ² = 5.36, P = .07). After adjusting for age, gender, and initial Dukes stage, the anemic patients demonstrated greater mortality rates than the nonanemic patients (hazard ratio, 1.73; 95% confidence interval, 1.05-2.86). The consistency with which the 2 independent reviewers were able to generate the rectal cancer regression grades from the historic pathology reports varied. Also, the subgroup analyses in the present study were often limited by low power.

CONCLUSION

The present large UK study examined patients receiving NCRT for magnetic resonance imaging-proven, locally advanced rectal adenocarcinoma. Our findings have demonstrated that patients who were anemic at presentation have higher regression grades (less regression) in response to the treatment than nonanemic patients. This trend appeared to persist despite radiologic disease stage at presentation. Anemia at presentation was also associated with increased mortality rates compared with that of nonanemic patients.

Manometric evaluation of anorectal function in patients treated with neoadjuvant chemoradiotherapy and total mesorectal excision for rectal cancer

BACKGROUND

An altered anorectal function is reported after chemoradiotherapy (CRT) and surgery for rectal cancer.

AIM

The aim of this study was to clarify the relative contribution of neoadjuvant chemoradiation and surgical resection on the impairment of anorectal function as evaluated by anorectal manometry.

METHODS

Thirty-nine patients with rectal cancer, who underwent neoadjuvant CRT and laparoscopic rectal resection, were evaluated with the Pescatori Faecal Incontinence score, and with anorectal manometry: before neoadjuvant therapy (T0), after neoadjuvant therapy and before surgery (T1), 12 months after stoma closure (T2).

RESULTS

Resting and/or maximum squeeze pressure and/or volume thresholds for urgency were below the normal values in 12 (30%) patients at baseline. After CRT the mean resting pressure significantly decreased (p=0.007). Surgery determined a significantly decrease of the resting pressure (p=0.001), of the maximum squeeze pressure (p=0.001) and of the volume threshold for urgency (p=0.001). Impairment of continence was reported by 5, 11 and 18 patients at T0, T1 and T2, with a mean incontinence score of 3, 3.8 and 3.9 respectively.

CONCLUSIONS

CRT is detrimental to the function of the internal anal sphincter. Rectal resection significantly affects both internal and external anal sphincter function and the maximum tolerated volume of the neo-rectum, particularly in patients with low rectal cancer, significantly impairing anal continence.

Assessment of pathological complete response to preoperative chemoradiotherapy by means of multiple mathematical models of diffusion-weighted MRI in locally advanced rectal cancer: A prospective single-center study

PURPOSE

To assess stretched-exponential, mono-exponential and intravoxel incoherent motion (IVIM) models of diffusion-weighted MRI(DWI) in predicting pathological complete response (pCR) to neoadjuvant chemoradiotherapy (CRT) in rectal cancer patients.

MATERIALS AND METHODS

This prospective study recruited 98 consecutive patients with locally advanced rectal cancer who underwent 3 Tesla MR examination before, during and after CRT. The apparent diffusion coefficient (ADC), IVIM-derived parameters (D, f, and D*), and stretched-exponential model-derived parameters (DDC and α) were measured. The parameters and their corresponding changes during and after CRT were compared between pCR and non-pCR. Receiver-operating characteristic curve analysis was performed to evaluate the diagnostic performance. Coefficient of variations and intraclass correlation coefficient were calculated to assess reliability and agreement.

RESULTS

Nineteen patients achieved pCR while 79 did not. The pCR group had higher ADC and α (ADC₂ and α₂ ), and their changes (ΔADC₂ , and Δα₂ ) at the endpoint than non-pCR group. α₂ and ADC₂ yielded similar AUCs (P = 0.339), Δα₂ and ΔADC₂ yielded similar AUCs (P = 0.263) ADC and α presented substantial agreement, and α presented the minimum CV (5.0-7.0%).

CONCLUSION

ADC and α were useful for assessing pCR after CRT. α might be more useful because it demonstrated better diagnostic performance than IVIM-derived parameters and better reliability than ADC.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:175-183.

Decreased PLK1 expression denotes therapy resistance and unfavourable disease-free survival in rectal cancer patients receiving neoadjuvant chemoradiotherapy

AIM

Polo-like kinase 1 (Plk1) plays a key role in mitotic cell division and DNA damage repair. It has been observed that either up-regulated or down-regulated Plk1 could induce mitotic defects that results in aneuploidy and tumorigenesis, probably depending on the context. Few previous reports have associated Plk1 expression with prognosis and response to radiotherapy in rectal carcinomas. The aim of this study is to investigate the prognostic impact of Plk1 expression and its role in predicting response to neoadjuvant cheomoradiotherapy in rectal cancer.

METHODS AND RESULTS

Immunohistochemical analysis of Plk1 expression was performed in the pre-treatment tumour specimens from 75 rectal cancer patients. We analysed the assocation between Plk1 expression and clinicopathological parameters, pathologic response and outcome. Opposed to previous reports on this issue, low expression of Plk1 was significantly associated with a high grade of differentiation (P=0.0007) and higher rate of distant metastasis (P=0.014). More importantly, decreased levels of Plk1 were associated with absence of response after neoadjuvant therapy (P=0.049). Moreover, low Plk1 expression emerged as an unfavourable prognostic factor for disease-free survival in the non-responder group of patients (P=0.037).

CONCLUSIONS

Decreased Plk1 expression was associated with poor pathologic response and worse disease-free survival in rectal cancer patients receiving neoadjuvant chemoradiotherapy, suggesting Plk1 as a clinically relevant marker to predict chemoradiotherapy response and outcome.

Influence of neoadjuvant chemoradiotherapy on the anal sphincter: ultrastructural damage may be critical

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) in addition to the curative surgery has been the first of treatment for local advanced rectal cancer because of its benefits in local recurrence and sphincter-saving. However, its side effects on anorectal function have been recognized. The histopathological changes on internal anal sphincter (IAS) have been reported, but ultrastructure changes of external anal sphincter (EAS) are unknown. The aim of this study is to detect the alterations on the gross morphology of IAS and ultrastructure of EAS after nCRT.

METHODS

We collected 34 anal canal specimens of patients undergoing abdominoperineal resection (APR) prospectively. The length and thickness of IAS were measured with vernier caliper. The EAS was dissected for observation with transmission electron microscope (TEM).

RESULTS

Ten patients received nCRT (nCRT group) before surgery and 24 underwent APR directly (control group). The length and thickness of IAS in nCRT group were 22.68 ± 3.56 and 5.39 ± 0.74 mm, respectively. These parameters were 21.28 ± 3.62 and 5.35 ± 1.12 mm in control group, respectively. There were no significant differences in the length and thickness of IAS between the two groups (P>0.05). In nCRT group, the sarcomere and myofibril were arranged disorderly and parts of them that were filled with collagenous fiber, triads, and mitochondria were destroyed severely and the glycogenosome also distributed disorderly. Such alterations of EAS did not occur in control group.

CONCLUSIONS

The nCRT cannot change the gross morphology of IAS, while it induces serious damages to the ultrastructures of EAS which may adversely affect the anorectal function.

Local recurrence after curative resection for rectal carcinoma: The role of surgical resection

Local recurrence of rectal cancer is difficult to treat, may cause severe and disabling symptoms, and usually has a fatal outcome. The aim of this study was to document the clinical nature of locally recurrent rectal cancer and to determine the effect of surgical resection on long-term survival.A retrospective review was conducted of the prospectively collected medical records of 2485 patients with primary rectal adenocarcinoma who underwent radical resection between September 1994 and December 2008.In total, 147 (5.9%) patients exhibited local recurrence. The most common type of local recurrence was lateral recurrence, whereas anastomotic recurrence was the most common type in patients without preoperative concurrent chemoradiotherapy (CCRT). Tumor location with respect to the anal verge significantly affected the local recurrence rate (P < 0.001), whereas preoperative CCRT did not affect the local recurrence rate (P = 0.433). Predictive factors for surgical resection of recurrent rectal cancer included less advanced tumor stage (P = 0.017, RR = 3.840, 95% CI = 1.271-11.597), axial recurrence (P < 0.001, RR = 5.772, 95% CI = 2.281-14.609), and isolated local recurrence (P = 0.006, RR = 8.679, 95% CI = 1.846-40.815). Overall survival after diagnosis of local recurrence was negatively influenced by advanced pathologic tumor stage (P = 0.040, RR = 1.867, 95% CI = 1.028-3.389), positive CRM (P = 0.001, RR = 12.939, 95% CI = 2.906-57.604), combined distant metastases (P = 0.001, RR = 2.086, 95% CI = 1.352-3.218), and nonsurgical resection of recurrent tumor (P < 0.001, RR = 4.865, 95% CI = 2.586-9.153).In conclusion, the clinical outcomes of local recurrence after curative resection of rectal cancer are diverse. Surgical resection of locally recurrent rectal cancer should be considered as an initial treatment, especially in patients with less advanced tumors and axial recurrence.

The spectrum of histopathological changes encountered in pancreatectomy specimens after neoadjuvant chemoradiation, including subtle and less-well-recognised changes

Preoperative (neoadjuvant) chemoradiation therapy/treatment (NCRT) is emerging as an important treatment modality in borderline resectable pancreatic ductal adenocarcinoma (PDAC). The constellation of histopathological changes secondary to chemoradiation is diverse and has been well documented, particularly in other gastrointestinal organs such as the oesophagus and colorectum. However, the histological changes specific to the pancreas have not been fully characterised and described. This review aims to provide a detailed catalogue of histological features associated with NCRT-treated PDAC and highlight any subtle, less-recognised changes.

Focal adhesion kinase: predictor of tumour response and risk factor for recurrence after neoadjuvant chemoradiation in rectal cancer

Rectal cancer represents about 30% of colorectal cancers, being around 50% locally advanced at presentation. Chemoradiation (CRT) followed by total mesorectal excision is the standard of care for these locally advanced stages. However, it is not free of adverse effects and toxicity and the complete pathologic response rate is between 10% and 30%. This makes it extremely important to define factors that can predict response to this therapy. Focal adhesion kinase (FAK) expression has been correlated with worse prognosis in several tumours and its possible involvement in cancer radio‐ and chemosensitivity has been suggested; however, its role in rectal cancer has not been analysed yet. To analyse the association of FAK expression with tumour response to CRT in locally advanced rectal cancer. This study includes 73 patients with locally advanced rectal cancer receiving standard neoadjuvant CRT followed by total mesorectal excision. Focal adhesion kinase protein levels were immunohistochemically analysed in the pre‐treatment biopsies of these patients and correlated with tumour response to CRT and patients survival. Low FAK expression was significantly correlated with local and distant recurrence (P = 0.013). Low FAK expression was found to be a predictive marker of tumour response to neoadjuvant therapy (P = 0.007) and patients whose tumours did not express FAK showed a strong association with lower disease‐free survival (P = 0.01). Focal adhesion kinase expression predicts neoadjuvant CRT response in rectal cancer patients and it is a clinically relevant risk factor for local and distant recurrence.

Predictive Response Value of Pre- and Postchemoradiotherapy Variables in Rectal Cancer: An Analysis of Histological Data

Background. Neoadjuvant chemoradiotherapy (nCRT) followed by curative surgery in locally advanced rectal cancer (LARC) improves pelvic disease control. Survival improvement is achieved only if pathological response occurs. Mandard tumor regression grade (TRG) proved to be a valid system to measure nCRT response. Potential predictive factors for Mandard response are analyzed. Materials and Methods. 167 patients with LARC were treated with nCRT and curative surgery. Tumor biopsies and surgical specimens were reviewed and analyzed regarding mitotic count, necrosis, desmoplastic reaction, and inflammatory infiltration grade. Surgical specimens were classified according to Mandard TRG. The patients were divided as "good responders" (Mandard TRG1-2) and "bad responders" (Mandard TRG3-5). According to results from our previous data, good responders have better prognosis than bad responders. We examined predictive factors for Mandard response and performed statistical analysis. Results. In univariate analysis, distance from anal verge and ten other postoperative variables related with nCRT tumor response had predictive value for Mandard response. In multivariable analysis only mitotic count, necrosis, and differentiation grade in surgical specimen had predictive value. Conclusions. There is a lack of clinical and pathological preoperative variables able to predict Mandard response. Only postoperative pathological parameters related with nCRT response have predictive value.

Watch and Wait?--Elevated Pretreatment CEA Is Associated with Decreased Pathological Complete Response in Rectal Cancer

INTRODUCTION

Between 10 and 30% of rectal cancer patients experience pathological complete response after neoadjuvant treatment. However, physiological factors predicting which patients will experience tumor response are largely unknown. Previous single-institution studies have suggested an association between elevated pretreatment carcinoembryonic antigen and decreased pathological complete response.

METHODS

Clinical stage II-III rectal cancer patients undergoing neoadjuvant chemoradiotherapy and surgical resection were selected from the 2006-2011 National Cancer Data Base. Multivariable analysis was used to examine the association between elevated pretreatment carcinoembryonic antigen and pathological complete response, pathological tumor regression, tumor downstaging, and overall survival.

RESULTS

Of the 18,113 patients meeting the inclusion criteria, 47% had elevated pretreatment carcinoembryonic antigen and 13% experienced pathological compete response. Elevated pretreatment carcinoembryonic antigen was independently associated with decreased pathological complete response (OR = 0.65, 95% CI = 0.52-0.77, p < 0.001), pathological tumor regression (OR = 0.74, 95% CI = 0.67-0.70, p < 0.001), tumor downstaging (OR = 0.77, 95% CI = 0.63-0.92, p < 0.001), and overall survival (HR = 1.45, 95% CI = 1.34-1.58, p < 0.001).

CONCLUSION

Rectal cancer patients with elevated pretreatment carcinoembryonic antigen are less likely to experience pathological complete response, pathological tumor regression, and tumor downstaging after neoadjuvant treatment and experience decreased survival. These patients may not be suitable candidates for an observational "watch-and-wait" strategy. Future prospective studies should investigate the relationships between CEA levels, neoadjuvant treatment response, recurrence, and survival.

New Perspectives on Predictive Biomarkers of Tumor Response and Their Clinical Application in Preoperative Chemoradiation Therapy for Rectal Cancer

Preoperative chemoradiation therapy (CRT) is the standard treatment for patients with locally advanced rectal cancer (LARC) and can improve local control and survival outcomes. However, the responses of individual tumors to CRT are not uniform and vary widely, from complete response to disease progression. Patients with resistant tumors can be exposed to irradiation and chemotherapy that are both expensive and at times toxic without benefit. In contrast, about 60% of tumors show tumor regression and T and N down-staging. Furthermore, a pathologic complete response (pCR), which is characterized by sterilization of all tumor cells, leads to an excellent prognosis and is observed in approximately 10-30% of cases. This variety in tumor response has lead to an increased need to develop a model predictive of responses to CRT in order to identify patients who will benefit from this multimodal treatment. Endoscopy, magnetic resonance imaging, positron emission tomography, serum carcinoembryonic antigen, and molecular biomarkers analyzed using immunohistochemistry and gene expression profiling are the most commonly used predictive models in preoperative CRT. Such modalities guide clinicians in choosing the best possible treatment options and the extent of surgery for each individual patient. However, there are still controversies regarding study outcomes, and a nomogram of combined models of future trends is needed to better predict patient response. The aim of this article was to review currently available tools for predicting tumor response after preoperative CRT in rectal cancer and to explore their applicability in clinical practice for tailored treatment.

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.

Extended Intervals after Neoadjuvant Therapy in Locally Advanced Rectal Cancer: The Key to Improved Tumor Response and Potential Organ Preservation

BACKGROUND

Many rectal cancer patients experience tumor downstaging and some are found to achieve a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT). Previous data suggest that there is an association between the time interval from nCRT completion to surgery and tumor response rates, including pCR. However, these studies have been primarily from single institutions with small sample sizes. The aim of this study was to examine the relationship between a longer interval after nCRT and pCR in a nationally representative cohort of rectal cancer patients.

STUDY DESIGN

Clinical stage II to III rectal cancer patients undergoing nCRT with a documented surgical resection were selected from the 2006 to 2011 National Cancer Data Base. Multivariable logistic regression analysis was used to assess the association between the nCRT-surgery interval time (<6 weeks, 6 to 8 weeks, >8 weeks) and the odds of pCR. The relationship between nCRT-surgery interval, surgical morbidity, and tumor downstaging was also examined.

RESULTS

Overall, 17,255 patients met the inclusion criteria. An nCRT-surgery interval time >8 weeks was associated with higher odds of pCR (odds ratio [OR] 1.12, 95% CI 1.01 to 1.25) and tumor downstaging (OR 1.11, 95% CI 1.02 to 1.25). The longer time delay was also associated with lower odds of 30-day readmission (OR 0.82, 95% CI 0.70 to 0.92).

CONCLUSIONS

An nCRT-surgery interval time >8 weeks results in increased odds of pCR, with no evidence of associated increased surgical complications compared with an interval of 6 to 8 weeks. These data support implementation of a lengthened interval after nCRT to optimize the chances of pCR and perhaps add to the possibility of ultimate organ preservation (nonoperative management).

YKL-40/c-Met expression in rectal cancer biopsies predicts tumor regression following neoadjuvant chemoradiotherapy: a multi-institutional study

BACKGROUND

Neoadjuvant chemo-radiotherapy (CRT) followed by surgical resection is the standard treatment for locally advanced rectal cancer, although complete tumor pathological regression is achieved in only up to 30% of cases. A clinicopathological and molecular predictive stratification of patients with advanced rectal cancer is still lacking. Here, c-Met and YKL-40 have been studied as putative predictors of CRT response in rectal cancer, due to their reported involvement in chemoradioresistance in various solid tumors.

MATERIAL AND METHODS

A multicentric study was designed to assess the role of c-Met and YKL-40 expression in predicting chemoradioresistance and to correlate clinical and pathological features with CRT response. Immunohistochemistry and fluorescent in situ hybridization for c-Met were performed on 81 rectal cancer biopsies from patients with locally advanced rectal adenocarcinoma. All patients underwent standard (50.4 gy in 28 fractions + concurrent capecitabine 825 mg/m2) neoadjuvant CRT or the XELOXART protocol. CRT response was documented on surgical resection specimens and recorded as tumor regression grade (TRG) according to the Mandard criteria.

RESULTS

A significant correlation between c-Met and YKL-40 expression was observed (R = 0.43). The expressions of c-Met and YKL-40 were both significantly associated with a lack of complete response (86% and 87% of c-Met and YKL-40 positive cases, p< 0.01 and p = 0.006, respectively). Thirty of the 32 biopsies co-expressing both markers had partial or absent tumor response (TRG 2-5), strengthening their positive predictive value (94%). The exclusive predictive role of YKL-40 and c-Met was confirmed using a multivariate analysis (p = 0.004 and p = 0.007 for YKL-40 and c-Met, respectively). TRG was the sole morphological parameter associated with poor outcome.

CONCLUSION

c-Met and YKL-40 expression is a reliable predictor of partial/absent response to neoadjuvant CRT in rectal cancer. Targeted therapy protocols could take advantage of prior evaluations of c-MET and YKL-40 expression levels to increase therapeutic efficacy.

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.

Predictive markers of response to neoadjuvant therapy in rectal cancer

BACKGROUND

Neoadjuvant therapy followed by radical surgery is the standard treatment in locally advanced rectal cancer. It is important to predict the response because the treatment has side effects and is costly. The aim of this study was to establish the relationship among clinical, pathologic, and molecular biomarkers and the response to neoadjuvant therapy.

METHOD

A total of 130 patients with locally advanced mid and low rectal cancer who underwent long-course radiotherapy with 5-FU based chemotherapy followed by radical surgical resection were included in the study. Clinical and pathologic data were collected. Paraffin-embedded sections obtained in diagnostic biopsies were assessed by immunohistochemical staining for molecular markers and classified using a semiquantitative method. Results were related with T-downstaging and tumor regression grade using Mandard scoring system on surgical specimens.

RESULTS

Pathologic complete response was found in 19 patients (14.6%), while in another 18 (13.8%) only minor residual disease was seen in the rectal wall. T-downstaging was observed in 63 (48.5%). The average of lymph node retrieval in the surgical specimens was 9.4. Regarding predictive markers of response, there was significant correlation between the expression of B-cell lymphoma 2 (P = 0.005), β-catenin (P = 0.03), vascular endothelial growth factor (P = 0.048) and apoptotic protease activating factor 1 (P = 0.03), tumor differentiation grade (P < 0.001), and response in the univariate analysis. T-downstaging was associated with vascular endothelial growth factor expression (P = 0.03) and tumor differentiation grade (P < 0.001). Significant parameters found in the multivariate analysis were tumor differentiation grade and Bcl-2 expression.

CONCLUSIONS

Pathologic and molecular biomarkers in the diagnostic biopsies may help us predict tumor response to chemoradiation in rectal cancer patients.

A circumferential resection margin of 1 mm is a negative prognostic factor in rectal cancer patients with and without neoadjuvant chemoradiotherapy

BACKGROUND

There is ongoing debate about the appropriate criterion for defining a positive circumferential resection margin after radical surgery for rectal cancer.

OBJECTIVE

The purpose of this work was to determine the importance of the extent of the circumferential resection margin with regard to outcomes in patients with rectal cancer who underwent total mesorectal excision with and without neoadjuvant chemoradiotherapy.

DESIGN

This was a retrospective review of prospectively collected data.

SETTINGS

The study was conducted in a tertiary care hospital.

PATIENTS

We reviewed the medical charts of 780 patients with rectal cancer who underwent radical surgery from 2004 to 2009. There were 599 patients (76.8%) who did not receive neoadjuvant chemoradiotherapy and 181 patients (23.2%) who did.

MAIN OUTCOME MEASURES

The relationship between the extent of the circumferential resection margin (0.5, 1.0, 2.0, and 3.0 mm) and recurrence and survival was assessed.

RESULTS

Among circumferential resection margins ≤0.5, ≤1.0, ≤2.0, and ≤3.0 mm, the HR was highest and disease-free survival was longest for a circumferential resection margin ≤1 mm in both the chemoradiotherapy and nonchemoradiotherapy groups. A circumferential resection margin ≤1 mm, lymphatic invasion, histology, pathologic T category, pathologic N category, preoperative CEA, and adjuvant chemotherapy were independent predictors of disease-free survival in the nonchemoradiotherapy group. In the chemoradiotherapy group, a circumferential resection margin ≤1 mm and histology were independent predictors of disease-free survival. Multivariate analysis revealed that a circumferential resection margin ≤1 mm was an independent prognostic factor for overall survival in both of the 2 groups.

LIMITATIONS

This was a single-institution, retrospective study.

CONCLUSIONS

A circumferential resection margin of ≤1 mm had a strong association with disease-free survival compared with circumferential resection margins ≤0.5, ≤2.0, and ≤3 mm. A circumferential resection margin ≤1 mm was an independent predictor of a poor outcome in both the nonchemoradiotherapy and chemoradiotherapy groups.

Abdominoperineal excision following preoperative radiotherapy for rectal cancer: Unfavorable prognosis even with negative circumferential resection margin

AIM: To evaluate whether an abdominoperineal excision (APE) is associated with increased local recurrence (LR) and shortened disease-free survival (DFS) in mid-low rectal cancer with a negative circumferential resection margin (CRM).

METHODS: 283 consecutive cases of mid-low rectal cancer underwent preoperative 30 Gy/10 F radiotherapy and surgery in Peking University Cancer Hospital between August 2003 and August 2009. Patients with positive CRM and intraoperative distant metastasis were precluded according to exclusion criteria. Survival analyses were performed in patients with APE or non-APE procedures.

RESULTS: 256 of the 283 (90.5%) cases were enrolled in the analysis, including 78 (30.5%) and 178 (69.5%) cases who received APE and non-APE procedures. Fewer female patients (P = 0.016), lower level of tumor (P = 0.000) and higher body mass index (P = 0.006) were found in the APE group. On univariate analysis, the APE group had a higher LR rate (5.1% vs 1.1%, P = 0.036) and decreased DFS (73.1% vs 83.4%, P = 0.021). On multivariate analysis, APE procedure was also an independent risk factor for LR (HR = 5.960, 1.085-32.728, P = 0.040) and decreased DFS (HR = 2.304, 1.298-4.092, P = 0.004). In stratified analysis for lower rectal cancer, APE procedure was still an independent risk factor for higher LR rate (5.6% vs 0%, P = 0.024) and shortened DFS (91.5% vs 73.6%, P = 0.002).

CONCLUSION: Following preoperative 30 Gy/10 F radiotherapy, APE procedure was still a predictor for LR and decreased DFS even with negative CRM. More intensive preoperative treatment should be planned for the candidates who are scheduled to receive APE with optimal imaging assessment.

Adjuvant treatment for locally advanced rectal cancer patients after preoperative chemoradiotherapy: when, and for whom?

BACKGROUND

The standard treatment for patients with locally advanced rectal cancer (clinical tumor, node, metastases [TNM] stage II or III) is radiotherapy before surgery (with or without concomitant fluoropyrimidine-based chemotherapy) followed by surgery. The role of adjuvant chemotherapy in this setting of patients is controversial in terms of the overall benefit on survival, the subgroup of patients who might not need it, and the best regimen (combination regimens vs. fluoropyrimidine alone).

PATIENTS AND METHODS

Based on the retrospective analysis of the clinical outcome of all patients with locally advanced rectal adenocarcinoma treated at our institute during the past 9 years, we comment on prognostic factors for local and distant metastases of patients who received neoadjuvant treatment followed by surgery, and the scientific evidence that can help to decide the adjuvant chemotherapy.

RESULTS

We conclude that pathological TNM stage after neoadjuvant chemoradiation (ypTNM) stage after surgery significantly affects disease-free and overall survival. In particular, patients with pathologically positive lymph nodes (ypN+) after surgery have a high probability of developing distant metastases.

CONCLUSION

ypN+ patients are candidate for intensified adjuvant chemotherapy.

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.

Intraoperative radiation therapy reduces local recurrence rates in patients with microscopically involved circumferential resection margins after resection of locally advanced rectal cancer

PURPOSE

Intraoperative radiation therapy (IORT) is advocated by some for patients with locally advanced rectal cancer (LARC) who have involved or narrow circumferential resection margins (CRM) after rectal surgery. This study evaluates the potentially beneficial effect of IORT on local control.

METHODS AND MATERIALS

All surgically treated patients with LARC treated in a tertiary referral center between 1996 and 2012 were analyzed retrospectively. The outcome in patients treated with IORT with a clear but narrow CRM (≤2 mm) or a microscopically involved CRM was compared with the outcome in patients who were not treated with IORT.

RESULTS

A total of 409 patients underwent resection of LARC, and 95 patients (23%) had a CRM ≤ 2 mm. Four patients were excluded from further analysis because of a macroscopically involved resection margin. In 43 patients with clear but narrow CRMs, there was no difference in the cumulative 5-year local recurrence-free survival of patients treated with (n=21) or without (n=22) IORT (70% vs 79%, P=.63). In 48 patients with a microscopically involved CRM, there was a significant difference in the cumulative 5-year local recurrence-free survival in favor of the patients treated with IORT (n=31) compared with patients treated without IORT (n=17) (84 vs 41%, P=.01). Multivariable analysis confirmed that IORT was independently associated with a decreased local recurrence rate (hazard ratio 0.24, 95% confidence interval 0.07-0.86). There was no significant difference in complication rate of patients treated with or without IORT (65% vs 52%, P=.18) CONCLUSION: The current study suggests that IORT reduces local recurrence rates in patients with LARC with a microscopically involved CRM.

Can a biomarker-based scoring system predict pathologic complete response after preoperative chemoradiotherapy for rectal cancer?

BACKGROUND

Numerous molecular markers have been investigated as potential predictors of tumor responses to preoperative chemoradiotherapy (preCRT) for rectal cancer.

OBJECTIVE

To develop a system in which biomarkers are used to predict the likelihood of a pathologic complete response (pCR) to preCRT.

DESIGN & SETTING

This is a retrospective analysis of tumor specimens collected prior to preCRT from 81 patients who underwent curative resection for primary rectal adenocarcinoma between June 2008 and February 2012.

MAIN OUTCOME MEASURES

Using tissue microarrays and immunohistochemistry, expression levels of twelve candidate biomarkers (p53, p21, Bcl2, Bax, EGFR, Cox-2, MLH-1, MSH-2, Ku70, VEGF, TS, Ki-67) were evaluated in paraffin-embedded tumor samples collected before preCRT. The correlation between biomarker expression levels and the pathologic response to preCRT was assessed based on histopathological staging (pTNM) and tumor regression grade (TRG).

RESULTS

Expression levels of 4 biomarkers (p53, VEGF, p21, Ki67) correlated with pCR. Patients showing low expression of p53 and/or high expression of VEGF, p21, and Ki67 exhibited a significantly greater pCR rate. A scoring system devised so that one point was given for each biomarker whose expression level correlated with pCR (score range: 0-4) showed that 1 of 26 patients with scores of 0 to 1 achieved pCR, whereas 26 of 55 patients with scores of 2 to 4 achieved pCR (3.8% vs. 47.3%, p < 0.001). For prediction of pCR, the scoring system showed 96.3% sensitivity, 46.3% specificity, a 47.3% positive predictive value, and a 96.2% negative predictive value.

LIMITATIONS

Immunohistochemistry has limitations related to reproducibility and the ability to provide quantitative information. In addition, this study lacks test and validation sets.

CONCLUSIONS

Expression levels of 4 biomarkers correlated with pCR after preCRT for rectal cancer. A scoring system based on levels of biomarker expression showed good sensitivity and negative predictive value for pCR.

Prognostic value of mandard and dworak tumor regression grading in rectal cancer: study of a single tertiary center

Goal. To evaluate the prognostic value of Mandard and Dworak grading systems regarding neoadjuvant chemoradiotherapy (CRT) response on rectal cancer. Materials and Methods. We queried our center's database for patients with colo rectal cancer with locally advanced rectal cancer (LARC) who received neoadjuvant CRT followed by total mesorectum excision (TME) between 2003 and 2011. After excluding 18 patients from the initial query the remaining 139 were reassessed for disease recurrence and survival; the specimens' slides were reviewed and classified according to two tumor regression grading (TRG) systems: Mandard and Dworak. Based on these TRG scores, two patient groups were created: patients with good response versus patients with bad response (Mandard TRG1+2 versus Mandard TRG3+4+5 and Dworak TRG4+3 versus Dworak TRG2+1+0). Overall survival (OS), disease-free survival (DFS), and disease recurrence were then evaluated. Results. Mean age was 64.2 years and median follow up was 56 months. No significant survival difference was found when comparing patients with Dworak TRG 4+3 versus Dworak TRG2+1+0 (P = 0.10). Mandard TRG1+2 presented with significantly better OS and DFS than Mandard TRG3+4+5 (OS P = 0.013; DFS P = 0.007). Conclusions. Mandard system provides higher accuracy over Dworak system in predicting rectal cancer prognosis when neoadjuvant CRT is applied for tumor regression.

Prognostic impact of circumferential resection margin in rectal cancer treated with preoperative chemoradiotherapy

BACKGROUND

The circumferential resection margin (CRM) is a strong prognostic factor in rectal cancer. The purpose of this study was to investigate the relationship between CRM distance and recurrence in patients with locally advanced rectal cancer who received preoperative chemoradiotherapy (CRT).

METHODS

We analyzed data for 561 patients who underwent preoperative CRT and curative surgery for locally advanced rectal cancer between August 2001 and December 2008. CRM was divided into four groups: group 1, CRM > 2 mm; group 2, 1.1-2.0 mm; group 3, 0.1-1.0 mm; and group 4, 0 mm. We assessed the associations of CRM with local recurrence and disease-free survival.

RESULTS

Groups 1, 2, 3, and 4 comprised 487, 36, 20, and 18 patients, respectively. The local recurrence rate was highest and the disease-free survival rate was lowest in group 4, followed by groups 3, 2, and 1. Survival was similar between groups 2 and 1. Local recurrence rates were lower in groups 3, 2, and 1 than in group 4 [hazard ratio (HR) 0.28, 95 % confidence interval (CI) 0.09-0.91, P = 0.035; HR 0.11, 95 % CI 0.03-0.46, P = 0.002; HR 0.18, 95 % CI 0.08-0.42, P < 0.0001, respectively]. Disease-free survival rates were higher in groups 3, 2, and 1 than in group 4 (HR 0.32, 95 % CI 0.13-0.75, P = 0.009; HR 0.24, 95 % CI 0.10-0.54, P = 0.001; HR 0.26, 95 % CI 0.14-0.48, P < 0.0001, respectively).

CONCLUSIONS

After preoperative CRT, CRM distance provides useful information for risk stratification in the recurrence of 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.

Risk factors for local recurrence following neoadjuvant chemoradiotherapy for rectal cancers

Local recurrence (LR) has an adverse impact on rectal cancer treatment. Neoadjuvant chemoradiotherapy (nCRT) is increasingly administered to patients with progressive cancers to improve the prognosis. However, LR still remains a problem and its pattern can alter. Correspondingly, new risk factors have emerged in the context of nCRT in addition to the traditional risk factors in patients receiving non-neoadjuvant therapies. These risk factors are decisive when reviewing treatment options. This review aims to elucidate the distinctive risk factors related to LR of rectal cancers in patients receiving nCRT and to clarify their clinical significance. A search was conducted on PubMed to identify original studies investigating patients with rectal cancer receiving nCRT. Outcomes of interest, especially potential risk factors for LR in patients with nCRT, were then analyzed. The clinical importance of these risk factors is discussed. Remnant cancer cells, lymph-nodes and tumor response were found to be major risk factors. Remnant cancer cells decide the status of resection margins. Local excision following nCRT is promising in ypT0-1N0M0 cases. Dissection of lateral lymph nodes should be considered in advanced low-lying cancers. Although better tumor response resulted in a relatively lower recurrence rate, the evidence available is insufficient to justify a non-operative approach in clinical complete responders to nCRT. LR cannot be totally avoided by current multidisciplinary approaches. The related risk factors resulting from nCRT should be considered when making decisions regarding treatment selection.

An individualized conditional survival calculator for patients with rectal cancer

BACKGROUND

Conditional survival estimates account for time survived since diagnosis to provide prognostic information for long-term cancer survivors. For rectal cancer, stage-related treatment (eg, neoadjuvant radiotherapy) affects pathologic stage and therefore stage-associated survival estimates.

OBJECTIVES

The aim of this study is to estimate conditional survival for patients who have rectal cancer and to develop an interactive calculator to use for individualized patient counseling.

PATIENTS

Patients with rectal adenocarcinoma were identified by using the Surveillance Epidemiology and End Results registry (1988-2002, N = 22,610).

DESIGN

Cox regression models were developed to determine adjusted survival estimates (years 1-10) and used to calculate 5-year adjusted conditional survival. Models were built separately for no radiotherapy, preoperative radiotherapy, postoperative radiotherapy, and patients with stage IV disease. Covariates included age, sex, race, tumor grade, and type of surgery. An Internet-based conditional survival calculator was developed.

RESULTS

Radiotherapy was given to 42.6% of patients (14.1% preoperative, 28.4% postoperative). Significant improvements in 5-year conditional survival were observed for all stages, with the exception of stage I because of the initial high survival probability at diagnosis. Patients with advanced stage had the greatest improvements in conditional survival, with 5-year absolute increases of 33% (stage IIIC) and 54% (IV). Other factors associated with conditional survival included sequence of radiotherapy and surgery, age, race, and tumor grade. The Internet-based conditional survival calculator can be accessed at www.mdanderson.org/rectalcalculator.

LIMITATIONS

The data source used does not include information on chemotherapy treatment, change in staging after neoadjuvant treatment, or patient comorbidities.

CONCLUSION

Conditional survival estimates improve over 5 years in patients who have rectal cancer; the greatest improvements are observed among patients with advanced stage disease. The conditional survival calculator is an individualized decision support tool that informs patients, who must make non-treatment-related life decisions, and their clinicians planning follow-up and surveillance.

Prevalence and significance of anaemia in patients receiving long-course neoadjuvant chemoradiotherapy for rectal carcinoma

AIM

The study aimed to assess the prevalence and significance of anaemia during long-course neoadjuvant radiotherapy for rectal cancer at our centre.

METHOD

Hospital coding and a prospective oncology database were used to identify all patients undergoing long-course neoadjuvant radiotherapy for rectal cancer at our centre between 2004 and 2009. A retrospective review of computerized records was used to extract individual patient data. Anaemia was defined as a haemoglobin level of < 11.5 g/dl for women and of < 13 g/dl for men. Downstaging was assessed by comparing radiological stage (rTNM) with histological stage (ypTNM). Tumour regression after radiotherapy was assessed using the Rectal Cancer Regression Group (RCRG) scores of 1-3. The results were analysed using Gnu PSPP statistical software.

RESULTS

There were 70 patients (51 men) of median age 66 (interquartile range 60-72.75) years. Of these, 24 were anaemic. Two (3%) had no haemoglobin level recorded and were excluded. Forty-two per cent of anaemic patients demonstrated mural (T) downstaging compared with 68% of nonanaemic patients (P = 0.03). There was no difference in nodal downstaging between the groups. The RCRG scores showed more tumour regression in nonanaemic patients than in anaemic patients, as follows: RCRG 1, 59%vs 30%; RCRG 2, 11%vs 17%; and RCRG 3, 38%vs 46% (P < 0.001).

CONCLUSION

The prevalence of anaemia in patients undergoing long-course neoadjuvant radiotherapy was 35%. Anaemia during long-course neoadjuvant radiotherapy was associated with significant reductions in tumour downstaging and regression.