Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

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.

Relationships between SMAD3 expression and preoperative fluoropyrimidine-based chemoradiotherapy response in locally advanced rectal cancer patients

BACKGROUND

SMAD3, which is accumulated in the nucleus, transcriptionally regulates TGF-β target genes, playing a significant role in mediating the activities of TGF-β. In this study, we assessed the roles of TGF-β1, SMAD3, and phosphorylated SMAD3 expressions in patients with locally advanced rectal cancer following preoperative fluoropyrimidine-based chemoradiotherapy.

METHODS

Using immunohistochemistry, we examined TGF-β1, SMAD3, and phosphorylated SMAD3 expressions in pre-chemoradiotherapy cancer tissues from 86 locally advanced rectal cancer patients. After chemoradiotherapy, 64 of 86 (74.4 %) locally advanced rectal cancer patients were classified as responders (pathological tumor regression grades of 2-4).

RESULTS

A multivariate analysis showed that phosphorylated SMAD3 overexpression correlated to poor preoperative chemoradiotherapy responses (P = 0.015; OR 7.218; 95 % CI 1.479-35.229). Furthermore, a poor response (pathological tumor regression grades of 0-1) was an independent predictor of postoperative relapse (P = 0.021; OR 5.452; 95 % CI 1.286-23.113). Additionally, patients with phosphorylated SMAD3 overexpression were found to have a worse disease-free survival (P = 0.023).

CONCLUSIONS

Our data suggested that analyzing pre-chemoradiotherapy tumors for phosphorylated SMAD3 overexpression would assist physicians in identifying locally advanced rectal cancer patients who may have a poor response risk to preoperative fluoropyrimidine-based chemoradiotherapy.

Prognostic relevance of stromal CD26 expression in rectal cancer after chemoradiotherapy

BACKGROUND

CD26 is a transmembrane glycoprotein whose role in various types of malignancies, along with the potential therapeutic and diagnostic targets, has been evaluated. Preoperative chemoradiotherapy (CRT) is an effective tool for local control of rectal cancer, but the rate of disease recurrence remains high. The aim of this study was to clarify the association between CD26 expression and rectal cancer after preoperative CRT.

METHODS

A total of 85 patients with rectal cancer who had undergone preoperative CRT were enrolled in this study. We investigated CD26 expression in residual tumors and the surrounding stromal tissue using immunohistochemistry. Additionally, stromal CD26 gene expression was assessed by real-time quantitative polymerase chain reaction.

RESULTS

Patients with high CD26 expression in cancer tissue more frequently had serosal invasion, vascular invasion, and a poor pathological response. High expression of CD26 in the tumor stroma was significantly correlated with histology and tumor recurrence. High CD26 expression in the stroma, but not the tumor itself, was significantly correlated with a poor prognosis. Patients expressing CD26 in the tumor stroma, based on transcriptional analysis, also had a significantly poorer prognosis than those without the expression. In multivariate analysis, lymph node metastasis and high stromal CD26 expression were identified as independent prognostic factors in patients with rectal cancer after neoadjuvant CRT.

CONCLUSION

Stromal CD26 expression after preoperative CRT was significantly associated with tumor recurrence and prognosis in rectal cancer patients. Our data suggest that stromal CD26 plays an important role and is a potential therapeutic target in tumor relapse.

Comparison of oncologic outcomes of metastatic rectal cancer patients with or without neoadjuvant chemoradiotherapy

PURPOSE

The aim of this study is to evaluate the effect of neoadjuvant chemoradiotherapy in stage IV rectal cancer.

METHODS

Primary rectal cancer patients with synchronous distant metastases between September 2001 and August 2011 were enrolled. Of 86 patients, 40 patients underwent neoadjuvant chemoradiotherapy (RTX group) and the remaining 46 patients underwent postoperative systemic chemotherapy without radiotherapy (NRTX group). Sharp mesorectal excision according to tumor location was performed. Oncologic outcomes were compared.

RESULTS

The lower tumor location was more common in RTX group than NRTX group (60.0 vs. 28.3%, P = 0.003). Clinical T and N status and American Society of Anesthesiologist (ASA) score were similar in both groups. The incidence of pathologic LN metastases in the NRTX group was 93.5% compared with 70.0% in RTX group (P = 0.007). Pattern of distant metastasis was similar between groups. However, metastatectomy was frequently performed in RTX group than NRTX group (57.5 vs. 30.4%, P = 0.020). There was no statistical difference in local recurrence rate between groups (10.0% in RTX vs. 15.2% in NRTX, P = 0.470). The median PFS was similar in both groups (12.00 months in RTX vs. 12.00 months in NRTX, P = 0.768). The median OS between groups was also not different (24.00 months in RTX vs. 27.00 months in NRT, P = 0.510).

CONCLUSIONS

Neoadjuvant chemoradiotherapy may not affect local control and overall survival in locally advanced rectal cancer with distant metastasis.

Clinical and prognostic significance of pathological and inflammatory markers in the surgical treatment of locally advanced colorectal cancer

Background

Locally advanced colorectal cancer (CRC) may vary in its clinical and pathological appearance. It is now accepted that progression of disease in patients with locally advanced CRC is determined not only by local tumor characteristics but also by the immune system and inflammatory response in the body.

Methods

We investigated patients with confirmed CRC who were treated in the surgical clinic at the University Hospital Alexandrovska over a 10-year period and retrospectively evaluated the histological features of the preoperative biopsies and operative specimens removed during radical multivisceral resections. We also collected prospective data for serum C-reactive protein levels and Jass-Klintrup score, Petersen Index score, and Glasgow Prognostic Score in patients with locally advanced CRC.

Results

Of 1,105 patients with CRC, 327 (29.6%) were diagnosed with locally advanced disease. In total, 108 combined multivisceral resections (79 for primary tumors and 29 for recurrent tumors) were performed. Overall survival was 34 months for pR0 cases and 12 months for pR1 cases (P<0.05). Our data confirmed that C-reactive protein is a prognostic marker of overall survival. Data for 48 patients with histologically confirmed locally advanced tumors showed significantly increased survival with a higher Jass-Klintrup score (P=0.037). In patients with node-negative disease, 5-year survival was 49%. However, where there were high-risk pathological characteristics according to the Petersen Index, survival was similar to that for node-positive disease (P=0.702). Our data also showed a significant difference in survival between groups divided according to whether they had a modified Glasgow Prognostic Score of 1 or 2 (P=0.031).

Conclusion

In order to maintain a reasonable balance between an aggressive approach and so-called meaningless “surgical exorbitance”, we should focus on certain histopathological and inflammatory markers that can be identified as additional factors for planning the type and volume of surgical treatment.

Early increase in circulating carbonic anhydrase IX during neoadjuvant treatment predicts favourable outcome in locally advanced rectal cancer

Background

Locally advanced rectal cancer (LARC) comprises heterogeneous tumours with predominant hypoxic components. The hypoxia-inducible metabolic shift causes microenvironmental acidification generated by carbonic anhydrase IX (CAIX) and facilitates metastatic progression, the dominant cause of failure in LARC.

Methods

Using a commercially available immunoassay, circulating CAIX was assessed in prospectively archived serial serum samples collected during combined-modality neoadjuvant treatment of LARC patients and correlated to histologic tumour response and progression-free survival (PFS).

Results

Patients who from their individual baseline level displayed serum CAIX increase above a threshold of 224 pg/ml (with 96 % specificity and 39 % sensitivity) after completion of short-course neoadjuvant chemotherapy (NACT) prior to long-course chemoradiotherapy and definitive surgery had significantly better 5-year PFS (94 %) than patients with below-threshold post-NACT versus baseline alteration (PFS rate of 56 %; p < 0.01). This particular CAIX parameter, ΔNACT, was significantly correlated with histologic ypT0–2 and ypN0 outcome (p < 0.01) and remained an independent PFS predictor in multivariate analysis wherein it was entered as continuous variable (p = 0.04).

Conclusions

Our results indicate that low ΔNACT, i.e., a weak increase in serum CAIX level following initial neoadjuvant treatment (in this case two cycles of the Nordic FLOX regimen), might be used as risk-adapted stratification to postoperative therapy or other modes of intensification of the combined-modality protocol in LARC.

Trial registration

ClinicalTrials.gov NCT00278694

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1557-6) contains supplementary material, which is available to authorized users.

Oncologic Impact of Fewer Than 12 Lymph Nodes in Patients Who Underwent Neoadjuvant Chemoradiation Followed by Total Mesorectal Excision for Locally Advanced Rectal Cancer

A minimum of 12 harvested lymph nodes (hLNs) are recommended in colorectal cancer. However, a paucity of hLNs is frequently presented after preoperative chemoradiation (pCRT) in rectal cancer and the significance of this is still uncertain. The aim of this study is to analyze the impact of hLNs on long-term oncologic outcomes. A total of 302 patients with locally advanced rectal cancer who underwent pCRT and curative resection between 1989 and 2009 were reviewed. Patients were categorized into 2 groups according to the number of hLNs: <12 versus ≥12 LN. The 2 groups were compared with respect to 5-year disease-free and overall survival. The optimal number or ratio of hLNs was investigated in subgroup analysis according to LN status. The median follow-up was 57 months. Patient characteristics other than age did not differ between the 2 groups. The group with <12 LNs had more favorable ypTNM and ypN stage than those with ≥12 LNs. However, the long-term oncologic outcomes were not significantly different between the 2 groups. In subgroup analysis of ypN(-), the group with <5 hLNs had the most favorable oncologic outcomes. In ypN(+) cases, a higher LN ratio tended to be associated with poorer 5-year overall survival. The paucity of hLNs in locally advanced rectal cancer after chemoradiation did not imply poor oncologic outcomes in this study. In addition, <5 hLNs in ypN(-) patients could reflect a good tumor response rather than suboptimal radicality.

Surveillance after neoadjuvant therapy in advanced rectal cancer with complete clinical response can have comparable outcomes to total mesorectal excision

PURPOSE

While the standard of care for patients with rectal cancer who sustain a complete clinical response (cCR) to chemoradiotherapy (CRT) remains proctectomy with total mesorectal excision, data suggests that non-operative management may be a safe alternative. The purpose of this study is to compare outcomes between patients treated with CRT that attained a cCR and opted for a vigilant surveillance to those of the patients who had a complete pathologic response (cPR) following proctectomy.

METHOD

This is a retrospective review of patients treated for adenocarcinoma of the rectum who achieved either a cCR or a cPR following CRT. Patients with a cCR were enrolled in an active surveillance program which included regularly scheduled exams, proctoscopy, serum carcinoembryonic antigen (CEA), endorectal ultrasound, and cross-sectional imaging. Outcomes were compared to those patients who underwent proctectomy with a cPR. Our primary outcome measures were post-treatment complications, recurrence, and survival.

RESULTS

We reviewed 18 patients who opted for surveillance after cCR and 30 patients who underwent proctectomy after a cPR. No non-operative patients had a documented treatment complication, while 17 patients with cPR suffered significant morbidity. There were two recurrences in the active surveillance group, one local and once distant, both treated by salvage resection with no associated mortality at 54 and 62 months. In the cPR group, one patient had a distant recurrence 24 months after surgery which was managed non-operatively. This patient died of unrelated causes 35 months after surgery.

CONCLUSIONS

Active surveillance can be a safe option that avoids the morbidity associated with proctectomy and preserves oncologic outcomes.

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.

The Impact of Surgical Diversion Before Neoadjuvant Therapy for Rectal Cancer

Up-front fecal diversion can palliate emergent symptoms related to locally advanced rectal cancer (LARC) allowing patients to receive neoadjuvant chemoradiation therapy (nCRT). We analyzed outcomes of pretreatment-diverted LARC patients relative to nondiverted patients to define the impact of this management strategy. We retrospectively collected data on 103 LARC patients treated with nCRTand surgery. Medical records were reviewed for patient characteristics, staging, treatment plan, and outcomes. Thirteen LARC patients underwent pretreatment diversion for urgent symptoms and 90 LARC patients proceeded directly to nCRT. In all, 50 per cent of diverted patients presented with T4 tumor compared with 14 per cent in the nondiverted patients ( P = 0.003). Diverted patients experienced a delay in time-to-treatment initiation of 12 days, although this difference was not statistically significant. Similar rates of chemoradiation and surgical toxicities were observed. Even though diverted patients demonstrated less pathologic response to nCRT compared with nondiverted patients ( P = 0.04), there was no significant difference in overall survival. In conclusion, our study demonstrates the effectiveness of up-front fecal diversion at managing emergent obstructive symptoms related to advanced rectal cancer without additional complications, allowing patients to proceed with nCRT followed by radical surgery.

The impact of surgical diversion before neoadjuvant therapy for rectal cancer

Up-front fecal diversion can palliate emergent symptoms related to locally advanced rectal cancer (LARC) allowing patients to receive neoadjuvant chemoradiation therapy (nCRT). We analyzed outcomes of pretreatment-diverted LARC patients relative to nondiverted patients to define the impact of this management strategy. We retrospectively collected data on 103 LARC patients treated with nCRT and surgery. Medical records were reviewed for patient characteristics, staging, treatment plan, and outcomes. Thirteen LARC patients underwent pretreatment diversion for urgent symptoms and 90 LARC patients proceeded directly to nCRT. In all, 50 per cent of diverted patients presented with T4 tumor compared with 14 per cent in the nondiverted patients (P = 0.003). Diverted patients experienced a delay in time-to-treatment initiation of 12 days, although this difference was not statistically significant. Similar rates of chemoradiation and surgical toxicities were observed. Even though diverted patients demonstrated less pathologic response to nCRT compared with nondiverted patients (P = 0.04), there was no significant difference in overall survival. In conclusion, our study demonstrates the effectiveness of up-front fecal diversion at managing emergent obstructive symptoms related to advanced rectal cancer without additional complications, allowing patients to proceed with nCRT followed by radical surgery.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The predictive value of 18F-FDG PET/CT for assessing pathological response and survival in locally advanced rectal cancer after neoadjuvant radiochemotherapy

PURPOSE

To evaluate whether metabolic changes in the primary tumour during and after preoperative radiochemotherapy (RCT) can predict the histopathological response in patients with locally advanced rectal cancer as well as disease-free survival (DFS) and overall survival (OS).

METHODS

Consecutive patients with cT2-4 N0-2 rectal adenocarcinoma were included. (18)F-FDG PET/CT was performed at baseline, at the end of the second week of RCT (early PET/CT) and before surgery (late PET/CT). The PET/CT results were compared with histopathological data (ypT0 N0 vs. ypT1-4 N0-2 as well as TRG1 vs.TRG2-5) and survival.

RESULTS

The study included 126 patients. Among 124 patients in whom TNM classification was available, 28 (22.6 %) were ypT0 N0, and among all 126 patients, 31 (24.6 %) were TRG1. The areas under the curve of the early response index (RI) for identifying non-complete pathological response (non-cPR) were 0.74 (95 % CI 0.61 - 0.87) for ypT1-4 N0-2 patients and 0.75 (95 % CI 0.62 - 0.88) for TRG2-5 patients. The optimal cut-off for differentiating patients with non-cPR and cPR was found to be a reduction of 61.2 % (83.1 % sensitivity and 65 % specificity in ypT1-4 N0-2 patients; 85.4 % sensitivity and 65.2 % specificity in TRG2-5 patients). The optimal cut-off for late RI could not be found. The qualitative analysis of images obtained after RCT demonstrated 81.5 % sensitivity and 61.3 % specificity in predicting TRG2-5. After a median follow-up of 68 months, the low number of patients with local/distant recurrence or who had died did not allow the value of PET/CT for predicting DFS and OS to be calculated.

CONCLUSION

The early assessment of response to RCT by (18)F-FDG PET/CT can predict non-cPR allowing practical modification of preoperative treatment. Conversely, late RI is not sufficiently accurate for guiding the decision as to whether local excision or even observation is appropriate in an individual patient. Qualitative analysis of late PET/CT images is also not sensitive enough alone to rule out the presence of residual disease.

Efficacy and safety of neoadjuvant intensity-modulated radiotherapy with concurrent capecitabine for locally advanced rectal cancer

BACKGROUND

We previously conducted a prospective phase II clinical trial studying a unique 22-fraction neoadjuvant intensity-modulated radiotherapy with concurrent capecitabine treatment followed by total mesorectal excision for locally advanced rectal cancer.

OBJECTIVE

The objective of this study was to retrospectively review the efficacy, toxicity, and surgical complications following intensity-modulated radiotherapy in patients who have rectal cancer.

DESIGN

This was a retrospective study.

SETTING

Data were gathered from a surgical database.

PATIENTS

This study included patients who underwent intensity-modulated radiotherapy with gross tumor volume/clinical target volume of 50.6/41.8 Gy in 22 fractions with concurrent capecitabine treatment over a period of 30 days, after which the patients underwent surgery for rectal cancer in Peking University Cancer Hospital (2007-2013).

MAIN OUTCOME MEASURES

The primary end points were acute toxicity, postoperative complications, and complete response rate.

RESULTS

A total of 260 patients were included in our analysis. The median age was 55 years (range, 21-87 years), and 68.5% of the patients were male. The yield complete response rate was 18.5% (48/260). There were no grade 4 toxicity and perioperative mortality. The grade 3 toxicity rate was 5.8%, which included diarrhea (4.2%), neutropenia (1.2%), and radiation dermatitis (0.4%). The 30-day postoperative and severe complication (≥grade 3) rates were 23.1% and 2.7%. The anastomotic leakage rate was 3.3% (5/152). Perineal wound complications (29.2%, 28/96) represented the most common problem following abdominoperineal resection. The estimated 3-year local recurrence-free survival, cancer-specific survival, and disease-free survival rates were 94.2% (95% CI, 90.1%-98.3%), 92.2% (95% CI, 87.5%-97.0%), and 81.4% (95% CI, 75.4%-87.4%).

LIMITATION

The retrospective nature and the single-arm design was the limitation of the study.

CONCLUSION

The 22-fraction neoadjuvant intensity-modulated radiotherapy regimen used to treat rectal cancer in this study has a high efficacy rate and a low toxicity rate. Further studies are needed to better define the role of intensity-modulated radiotherapy for rectal cancer treatment in a neoadjuvant setting.

Avoiding radical surgery improves early survival in elderly patients with rectal cancer, demonstrating complete clinical response after neoadjuvant therapy: results of a decision-analytic model

BACKGROUND

In elderly and comorbid patients with rectal cancer, radical surgery is associated with significant perioperative mortality. Data suggest that a watch-and-wait approach where a complete clinical response is obtained after neoadjuvant chemoradiotherapy might be oncologically safe.

OBJECTIVE

This study aimed to determine whether patient age and comorbidity should influence surgeon and patient decision making where a complete clinical response is obtained.

DESIGN

Decision-analytic modeling consisting of a decision tree and Markov chain simulation was used. Modeled outcome parameters were elicited both from comprehensive literature review and from a national patient outcomes database.

SETTINGS

Outcomes for 3 patient cohorts treated with neoadjuvant therapy were modeled after either surgery or watch and wait.

PATIENTS

Patients included 60-year-old and 80-year-old men with mild comorbidities (Charlson score <3) and 80-year-old men with significant comorbidities (Charlson score >3).

MAIN OUTCOME MEASURES

Absolute survival, disease-free survival, and quality-adjusted life years were measured.

RESULTS

The model found that absolute survival was similar in 60-year-old patients but was significantly improved in fit and comorbid 80-year-old patients at 1 year after treatment where watch and wait was implemented instead of radical surgery, with a survival advantage of 10.1% (95% CI, 7.9-12.6) and 13.5% (95% CI, 10.2-16.9). At all of the other time points, absolute survival was equivalent for both techniques. There were no short- or long-term differences among any patient groups managed either by radical surgery or watch and wait in terms of either disease-free survival or quality-adjusted life years.

LIMITATIONS

Oncologic data for the watch-and-wait approach used for this study is derived from only a small number of studies pertaining to a highly selected group of patients. The 90-day postoperative mortality rate derived from the United Kingdom population-based study might be lower in other countries or individual institutions.

CONCLUSIONS

This study suggests competing effects of oncologic and surgical risk when using watch-and-wait management and that elderly and comorbid patients have the most to gain from this approach.

Two-week Course of Preoperative Radiotherapy for Locally Advanced Rectal Adenocarcinoma: 8 Years' Experience in a Single Institute

OBJECTIVES

To evaluate local control and survival in locally advanced rectal adenocarcinoma patients who underwent a preoperative 2-week course of radiotherapy (RT) and to identify prognostic factors influencing the survival rate.

METHODS

We analyzed 377 consecutively treated patients with locally advanced (T3/T4 or node positive) rectal adenocarcinoma. All patients underwent a preoperative 2-week course of RT (30 Gy in 10 fractions) followed by curative surgery. Regression model was used to examine prognostic factors for the disease-free survival (DFS) and overall survival (OS) rates. The Statistical Analysis System software package, version 9.3, was used for analysis.

RESULTS

The median follow-up for all living patients was 63.8 months (range, 5.1 to 131.7). The 5-year DFS and OS rates were 64.5% (95% CI, 59.0-69.4) and 75.6% (95% CI, 70.5-80.0), respectively. The 5-year cumulative incidences of local recurrence and distant metastases were 5.4% (95% CI, 2.9-7.9) and 29.0% (95% CI, 23.9-30.1), respectively. The pathologic complete response rate was achieved in 17 patients (4.5%). The Multivariate Cox Regression model showed that factors affecting DFS were the surgical technique, pre-RT pathologic grade, ypT, ypN, and comorbidity; and factors improving OS were low anterior resection, low pre-RT grade, low ypT, and low ypN.

CONCLUSIONS

Patients treated with preoperative RT with 30 Gy in 10 fractions had similar local control, 5-year DFS and OS to reported long course RT regimen. The surgical technique, pre-RT pathologic grade, ypT, and ypN seemed to affect the OS. Further study on combining a 2-week course of preoperative RT with concurrent chemotherapy would be warranted.

Adjuvant chemotherapy in rectal cancer: defining subgroups who may benefit after neoadjuvant chemoradiation and resection: a pooled analysis of 3,313 patients

Recent literature suggests that the benefit of adjuvant chemotherapy (aCT) for rectal cancer patients might depend on the response to neoadjuvant chemoradiation (CRT). Aim was to evaluate whether the effect of aCT in rectal cancer is modified by response to CRT and to identify which patients benefit from aCT after CRT, by means of a pooled analysis of individual patient data from 13 datasets. Patients were categorized into three groups: pCR (ypT0N0), ypT1-2 tumour and ypT3-4 tumour. Hazard ratios (HR) for the effect of aCT were derived from multivariable Cox regression analyses. Primary outcome measure was recurrence-free survival (RFS). One thousand seven hundred and twenty three (1723) (52%) of 3,313 included patients received aCT. Eight hundred and ninety eight (898) patients had a pCR, 966 had a ypT1-2 tumour and 1,302 had a ypT3-4 tumour. For 122 patients response, category was missing and 25 patients had ypT0N+. Median follow-up for all patients was 51 (0-219) months. HR for RFS with 95% CI for patients treated with aCT were 1.25(0.68-2.29), 0.58(0.37-0.89) and 0.83(0.66-1.10) for patients with pCR, ypT1-2 and ypT3-4 tumours, respectively. The effect of aCT in rectal cancer patients treated with CRT differs between subgroups. Patients with a pCR after CRT may not benefit from aCT, whereas patients with residual tumour had superior outcomes when aCT was administered. The test for interaction did not reach statistical significance, but the results support further investigation of a more individualized approach to administer aCT after CRT and surgery based on pathologic staging.

Analysis of stage and clinical/prognostic factors for colon and rectal cancer from SEER registries: AJCC and collaborative stage data collection system

BACKGROUND

The Collaborative Stage (CS) Data Collection System enables multiple cancer registration programs to document anatomic and molecular pathology features that contribute to the Tumor (T), Node (N), Metastasis (M) - TNM - system of the American Joint Committee on Cancer (AJCC). This article highlights changes in CS for colon and rectal carcinomas as TNM moved from the AJCC 6th to the 7th editions.

METHODS

Data from 18 Surveillance, Epidemiology, and End Results (SEER) population-based registries were analyzed for the years 2004-2010, which included 191,361colon and 73,341 rectal carcinomas.

RESULTS

Overall, the incidence of colon and rectal cancers declined, with the greatest decrease in stage 0. The AJCC's 7th edition introduction of changes in the subcategorization of T4, N1, and N2 caused shifting within stage groups in 25,577 colon and 10,150 rectal cancers diagnosed in 2010. Several site-specific factors (SSFs) introduced in the 7th edition had interesting findings: 1) approximately 10% of colon and rectal cancers had tumor deposits - about 30%-40% occurred without lymph node metastases, which resulted in 2.5% of colon and 3.3% of rectal cases becoming N1c (stage III A/B) in the AJCC 7th edition; 2) 10% of colon and 12% of rectal cases had circumferential radial margins <1 mm; 3) about 46% of colorectal cases did not have a carcinoembryonic antigen (CEA) testing or documented CEA information; and 4) about 10% of colorectal cases had perineural invasion.

CONCLUSIONS

Adoption of the AJCC 7th edition by the SEER program provides an assessment tool for staging and SSFs on clinical outcomes. This evidence can be used for education and improved treatment for colorectal carcinomas.

Learning curve of laparoscopic low anterior resection in terms of local recurrence

BACKGROUND

Experience in terms of surgical case numbers required to develop proficiency for oncologic adequacy after sphincter-saving laparoscopic rectal cancer surgery has not been established.

METHOD

Three hundred seventeen consecutive patients underwent sphincter-saving laparoscopic rectal cancer surgery with curative intent performed by single surgeon. The learning curve was estimated using risk-adjusted cumulative sum (RA-CUSUM) and the graph of 195 consecutive patients who were treated by another surgeon was used to evaluate inter-surgeon variability in the learning curve.

RESULTS

Overall, the 3-year local recurrence rate was 7.7% (95% confidence interval [CI], 6.4%-9.0%). The RA-CUSUM analysis demonstrated a learning curve of 110 cases for local recurrence for both of surgeons and 50-70 cases for CRM involvement. The 3-year local recurrence-free rate was better during the experienced period than during the learning period (95.1% [95% CI, 91.6%-97.1%] vs. 89.5% [95% CI, 84.4%-93.0%]; P = 0.029). These differences were obvious in subgroup analysis of stage III tumors (93.4% [95% CI, 86.6%-96.8%] vs. 78.6% [95% CI, 68.5%-85.3%]; P = 0.013).

CONCLUSIONS

Local recurrence rates decreased with increasing surgeon experience, as did other short-term outcomes, especially in advanced disease cases.

Pretreatment evaluation of microcirculation by dynamic contrast-enhanced magnetic resonance imaging predicts survival in primary rectal cancer patients

PURPOSE

To investigate the prognostic value of the perfusion index (PI), a microcirculatory parameter estimated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), which integrates information on both flow and permeability, to predict overall survival and disease-free survival in patients with primary rectal cancer.

METHODS AND MATERIALS

A total of 83 patients with stage cT3 rectal cancer requiring neoadjuvant chemoradiation were investigated with DCE-MRI before start of therapy. Contrast-enhanced dynamic T1 mapping was obtained, and a simple data analysis strategy based on the calculation of the maximum slope of the tissue concentration-time curve divided by the maximum of the arterial input function was used as a measure of tumor microcirculation (PI), which integrates information on both flow and permeability.

RESULTS

In 39 patients (47.0%), T downstaging (ypT0-2) was observed. During a mean (±SD) follow-up period of 71 ± 29 months, 58 patients (69.9%) survived, and disease-free survival was achieved in 45 patients (54.2%). The mean PI (PImean) averaged over the group of nonresponders was significantly higher than for responders. Additionally, higher PImean in age- and gender-adjusted analyses was strongly predictive of therapy nonresponse. Most importantly, PImean strongly and significantly predicted disease-free survival (unadjusted hazard ratio [HR], 1.85 [ 95% confidence interval, 1.35-2.54; P<.001)]; HR adjusted for age and sex, 1.81 [1.30-2.51]; P<.001) as well as overall survival (unadjusted HR 1.42 [1.02-1.99], P=.040; HR adjusted for age and sex, 1.43 [1.03-1.98]; P=.034).

CONCLUSIONS

This analysis identifies PImean as a novel biomarker that is predictive for therapy response, disease-free survival, and overall survival in patients with primary locally advanced rectal cancer.

Impact of perineural and lymphovascular invasion on oncological outcomes in rectal cancer treated with neoadjuvant chemoradiotherapy and surgery

BACKGROUND

The prognostic significance of perineural and/or lymphovascular invasion (PLVI) and its relationship with tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT) and surgery.

METHODS

A total of 324 patients with LARC were treated with CRT and operated on between January 1992 and June 2007. Tumors were graded using a quantitative 5-grade TRG classification and the presence of PLVI was histologically studied.

RESULTS

At a median follow-up of 79.0 months (range 3-250 months), a total of 80 patients (24.7%) relapsed. The observed 5- and 10-year overall survival (OS) was 83.2 and 74.9 %, respectively. The 5- and 10-year disease-free survival (DFS) was 75.1 and 71.4%, respectively. A significant correlation was found between the TRG and survival (log rank, p < 0.001). The 10-year OS was 32.7% for grade 1, 63.8% for grade 2, 75.0% for grade 3, 90.4% for grade 3+, and 96.0%,for grade 4. The 10-year DFS was 31.8% for grade 1, 58.6% for grade 2, 70.4% for grade 3, 88.4% for grade 3+, and 97.1% for grade 4. In patients with PLVI, the TRG had no impact on survival. When excluding patients with PLVI, the TRG was an independent prognostic factor for OS and DFS.

CONCLUSIONS

The presence of PLVI is a more powerful prognostic factor than TRG in LARC patients treated with neoadjuvant CRT followed by surgery. PLVI denotes an aggressive phenotype, suggesting that these patients may benefit from adjuvant systemic therapy.

Reduction in the size of enlarged pelvic lymph nodes after chemoradiation therapy is associated with fewer lymph node metastases in locally advanced rectal carcinoma

PURPOSE

We hypothesized that a reduction in the size of the lymph nodes after neoadjuvant therapy for locally advanced rectal carcinoma would be associated with decreased lymph node metastases and/or a better prognosis.

METHODS

Between March 2006 and April 2012, 71 patients with primary rectal cancer received neoadjuvant chemoradiation therapy (CRT). For all lymph nodes 5 mm or larger in size, the major and minor axes were measured on CT scan images, and the product was calculated. The lymph node size was determined before and after CRT. The patients were divided into three groups based on the lymph node size before and after treatment. Group A exhibited a reduction in size of 60% or more, Group B a reduction of less than 60% and Group C had no lymph node enlargement before treatment.

RESULTS

The incidence of lymph node metastases on pathological examination was 15% in Group A and 50% in Group B (p = 0.006). The five-year disease-free survival in Group A was 84% compared with 78% in Group B (log rank p = 0.34). The five-year overall survival in Group A was 92% compared with 74% in Group B (log rank p = 0.088).

CONCLUSIONS

A reduction in the size of enlarged lymph nodes after neoadjuvant therapy may be a useful prognostic factor for recurrence and survival.

Overexpression of CPS1 is an independent negative prognosticator in rectal cancers receiving concurrent chemoradiotherapy

Locally advanced rectal cancers are currently treated with neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery, but stratification of risk and final outcomes remain suboptimal. In view of the fact that glutamine metabolism is usually altered in cancer, we profiled and validated the significance of genes involved in this pathway in rectal cancers treated with CCRT. From a published transcriptome of rectal cancers (GSE35452), we focused on glutamine metabolic process-related genes (GO:0006541) and found upregulation of carbamoyl phosphate synthetase 1 (CPS1) gene most significantly predicted poor response to CCRT. We evaluated the expression levels of CPS1 using immunohistochemistry to analyze tumor specimens obtained during colonoscopy from 172 rectal cancer patients. Expression levels of CPS1 were further correlated with major clinicopathological features and survivals in this validation cohort. To further confirm CPS1 expression levels, Western blotting was performed for human colon epithelial primary cell (HCoEpiC) and four human colon cancer cells, including HT29, SW480, LoVo, and SW620. CPS1 overexpression was significantly related to advanced posttreatment tumor (T3, T4; P = 0.006) and nodal status (N1, N2; P < 0.001), and inferior tumor regression grade (P = 0.004). In survival analyses, CPS1 overexpression was significantly associated with shorter disease-specific survival (DSS) and metastasis-free survival (MeFS). Furthermore, using multivariate analysis, it was also independently predictive of worse DSS (P = 0.021, hazard ratio = 2.762) and MeFS (P = 0.004, hazard ratio = 3.897). CPS1 protein expression, as detected by Western blotting, is more abundant in colon cancer cells than nonneoplastic HCoEpiC. Overexpression of CPS1 is associated with poor therapeutic response and adverse outcomes among rectal cancer patients receiving CCRT, justifying the potential theranostic value of CPS1 for such patients.

Simple measurements on diffusion-weighted MR imaging for assessment of complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

PURPOSE

To determine diagnostic performance of simple measurements on diffusion-weighted MR imaging (DWI) for assessment of complete tumour response (CR) after neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC) by signal intensity (SI) and apparent diffusion coefficient (ADC) measurements.

MATERIALS AND METHODS

Sixty-five patients with LARC who underwent neoadjuvant CRT and subsequent surgery were included. Patients underwent pre-CRT and post-CRT 3.0 T MRI. Regions of interest of the highest brightness SI were included in the tumour volume on post-CRT DWI to calculate the SIlesion, rSI, ADClesion and rADC; diagnostic performance was compared by using the receiver operating characteristic (ROC) curves. In order to validate the accuracy and reproducibility of the current strategy, the same procedure was reproduced in 80 patients with LARC at 1.5 T MRI.

RESULTS

Areas under the ROC curve for identification of a CR, based on SIlesion, rSI, ADClesion, and rADC, respectively, were 0.86, 0.94, 0.66, and 0.71 at 3.0 T MRI, and 0.92, 0.91, 0.64, and 0.61 at 1.5 T MRI.

CONCLUSION

Post-CRT DWI SIlesion and rSI provided high diagnostic performance in assessing CR and were significantly more accurate than ADClesion, and rADC at 3.0 T MRI and 1.5 T MRI.

KEY POINTS

• Signal intensity (SI lesion ) and rSI are accurate for assessment of complete response. • rSI seems to be superior to SI lesion at 3.0 T MRI. • ADC or rADC measurements are not accurate for assessment of complete response.

Tumour regression grading after chemoradiotherapy for locally advanced rectal cancer: a near pathologic complete response does not translate into good clinical outcome

BACKGROUND

After preoperative chemoradiotherapy (CRT) for rectal cancer, clinically undetectable residual tumour deposits or pathologic lymph nodes may remain in the mesorectum.

AIM

The aim of this study was to report histopathological effects of CRT and factors affecting outcome in a uniformly treated series of locally advanced rectal cancer (LARC) patients.

METHODS

Between 2004 and 2008, 107 patients with cT3 (threatening the mesorectal fascia or <5 cm from the anal verge), cT4 or cN2 rectal cancer were treated with preoperative CRT (25 × 2 Gy with capecitabine) and TME 6-8 weeks later. Central histopathological review followed. Tumour regression grade (TRG) was scored in pCR, near-pCR, response and no response. Cox regression was performed to identify prognosticators.

RESULTS

The 3-year distant metastasis-free interval, disease-free rate and overall survival rate were 82%, 73% and 87% (median 44 months follow-up). TRG consisted of 20% pCR, 11% near-pCR, 55% response and 14% no response. 6/21 pCR patients harboured nodal metastases. 5/12 near-pCR had ypT3 disease, while 6 harboured node metastases. 5/12 near-PCR patients developed distant metastases. ypN and TRG were powerful outcome discriminators.

CONCLUSION

The high number of near-pCR with ypT3 or ypN1/2 and their poor outcome demonstrates that "watch-and-wait" in LARC patients should be applied with care.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

What factors influence 10-year survival after curative resection of a colorectal carcinoma?

BACKGROUND

Ten-year survival rates are only rarely reported and frequently include a large proportion of censored data-that is, most of the patients have not survived the 10 years. We therefore selected patients in a prospectively maintained, hospital-based tumor register who had been operated on for colorectal carcinoma (CRC) more than 10 years earlier and who were classified as long-term survivors.

METHODS

For 589 consecutive CRC patients who underwent R0 resection in the period 1990-1998, we compared prognosis-relevant characteristics and calculated the survival rate as a function of age, sex, location of the tumor, general state of health, urgency of the operation, and pT and pN class. All patients were observed until their death or until at least 10 years after resection. Patients who died of other causes were censored. Overall survival and relative survival (the latter based on tumor-related death) were assessed.

RESULTS

The 10-year survivors were more often female (not significant), younger (p < 0.001), in good general health (p < 0.001), had undergone elective resection (p < 0.001), and had early-stage tumors (p < 0.001). In the univariate analysis emergency operation, impaired general health, invasion beyond the muscularis propria, and lymph-node metastasis were found to reduce relative survival. In the multivariate analysis, location, emergency resection, pT, and pN were found to be statistically independent risk factors.

CONCLUSIONS

Long-term freedom from tumor recurrence, like-short-term, is influenced largely by factors that are beneficially influenced by early recognition. The patient's age at resection is immaterial.

Neoadjuvant capecitabine and oxaliplatin (XELOX) combined with bevacizumab for high-risk localized rectal cancer

PURPOSE

Chemoradiotherapy followed by total mesorectal excision (TME) is the standard treatment for locally advanced rectal cancer. Although this approach decreases the risk of local recurrence, pelvic radiation is associated with long-term morbidity and delays systemic treatment. We conducted this study to evaluate the feasibility of neoadjuvant capecitabine and oxaliplatin (XELOX) plus bevacizumab as a treatment for high-risk localized rectal cancer.

METHODS

Patients with T4 or lymph node-positive rectal cancer were treated with three cycles of XELOX plus bevacizumab and one additional cycle of XELOX. This was followed by TME performed 3-8 weeks after the last chemotherapy session.

RESULTS

Twenty-five patients were recruited between December 2009 and November 2011. In seven of the patients (28.0 %), grade 3-4 adverse events occurred. After preoperative chemotherapy, the frequency of tumor (T) downstaging was 69.6 %, and that of lymph node (N) downstaging was 78.9 %. Seven patients discontinued the treatment after 2-3 cycles of XELOX plus bevacizumab. The frequency of subsequent surgery was 92 %, and all patients underwent R0 resections. Postoperative complications occurred in six patients (26.1 %). One patient achieved a pathological complete response (pCR) for the primary tumor and lymph nodes, whereas an additional four patients achieved near-pCR. After a median follow-up of 31 months, five patients displayed metastatic progression, including one who suffered local recurrence.

CONCLUSIONS

XELOX plus bevacizumab followed by TME is feasible for high-risk localized rectal cancer, as it achieves good tumor regression and causes manageable toxicity.

Histogenesis and prognostic value of myenteric spread in colorectal cancer: a Japanese multi-institutional study

BACKGROUND

The histogenesis of the pattern of cancer spread along Auerbach's plexus (myenteric spread: MS) remains unclear and its prognostic value in colorectal cancer (CRC) has not been thoroughly investigated.

METHODS

Pathology slides of 2845 pT2/pT3/pT4 CRCs stained with hematoxylin-eosin (H&E) were reviewed at 10 institutions. MS was classified into 2 groups depending on whether it was accompanied by the finding of perineural invasion (PN) within the lesion. In addition, immunohistochemical staining (D2-40, S100, CD56, synaptophysin) was performed for serially sectioned specimens from 50 CRCs diagnosed as having PN-negative MS.

RESULTS

MS was observed in 504 patients (17.7 %); 360 patients were classified as having PN-positive MS and 144 as having PN-negative MS. The 5-year disease-free survival rate of patients with MS was lower than that of patients without MS (63.3 vs 82.7 %, P < 0.0001); however, there was no significant difference in survival outcome according to the presence or absence of intralesion PN in MS. Multivariate analysis showed that the prognostic impact of MS was independent of conventional prognosticators including T and N stages, vascular invasion and extramural PN. In all the tumors having PN-negative MS, remnants of neural tissue were identified within or around cancer nests located at the leading edge of MS.

CONCLUSIONS

MS is an important prognostic factor for CRC. This feature is the result of cancer development with replacement of Auerbach's plexus and can be classified as intramural PN. The clinical significance of "Pn1" in the UICC/AJCC TNM classification could be enhanced by individual assessment both intramurally and extramurally.

Coexistence of perineural invasion and lymph node metastases is a poor prognostic factor in patients with locally advanced rectal cancer after preoperative chemoradiotherapy followed by radical resection and adjuvant chemotherapy

OBJECTIVE

To determine the role of lymph node metastases (ypN) and perineural invasion (PNI) in patients with locally advanced rectal cancer (LARC).

SUBJECTS AND METHODS

Eighty-eight LARC patients receiving preoperative chemoradiotherapy from April 2006 to November 2011 were enrolled in this study. Univariate and multivariate analyses were conducted to determine the association between clinicopathologic features and clinical outcome.

RESULTS

The presence of ypN (p = 0.011) and PNI (p = 0.032) was a significant adverse prognostic factor for disease-free survival (DFS). High histologic grade (p = 0.015), PNI+ (p = 0.043) and ypN+ (p = 0.041) were adverse prognostic factors for overall survival (OS). Positive PNI was significantly associated with a higher risk of distant failure (odds ratio = 6.09; 95% CI: 1.57-27.05; p = 0.008). Moreover, patients with a coexistence of ypN+ and PNI+ had the significantly worst DFS (p < 0.001) and OS rates (p < 0.001) compared with other phenotypes.

CONCLUSIONS

The presence of either PNI or ypN was a significant prognostic factor for predicting poor survival rates in LARC patients, especially those with a coexistence of both factors. Accordingly, we recommend an intensive follow-up and therapeutic programs for LARC patients with simultaneous PNI+ and ypN+.

DPYD, TYMS, TYMP, TK1, and TK2 genetic expressions as response markers in locally advanced rectal cancer patients treated with fluoropyrimidine-based chemoradiotherapy

This study is to investigate multiple chemotherapeutic agent- and radiation-related genetic biomarkers in locally advanced rectal cancer (LARC) patients following fluoropyrimidine-based concurrent chemoradiotherapy (CCRT) for response prediction. We initially selected 6 fluoropyrimidine metabolism-related genes (DPYD, ORPT, TYMS, TYMP, TK1, and TK2) and 3 radiotherapy response-related genes (GLUT1, HIF-1α, and HIF-2α) as targets for gene expression identification in 60 LARC cancer specimens. Subsequently, a high-sensitivity weighted enzymatic chip array was designed and constructed to predict responses following CCRT. After CCRT, 39 of 60 (65%) LARC patients were classified as responders (pathological tumor regression grade 2 ~ 4). Using a panel of multiple genetic biomarkers (chip), including DPYD, TYMS, TYMP, TK1, and TK2, at a cutoff value for 3 positive genes, a sensitivity of 89.7% and a specificity of 81% were obtained (AUC: 0.915; 95% CI: 0.840–0.991). Negative chip results were significantly correlated to poor CCRT responses (TRG 0-1) (P = 0.014, hazard ratio: 22.704, 95% CI: 3.055–235.448 in multivariate analysis). Disease-free survival analysis showed significantly better survival rate in patients with positive chip results (P = 0.0001). We suggest that a chip including DPYD, TYMS, TYMP, TK1, and TK2 genes is a potential tool to predict response in LARC following fluoropyrimidine-based CCRT.

Lack of M30 expression correlates with factors reflecting tumor progression in rectal cancer with preoperative chemoradiotherapy

Preoperative chemoradiotherapy (CRT) is an effective tool for local control that functions by inducing cancer cell apoptosis and inhibiting cell growth. The aim of this study was to evaluate the expression of caspase-cleaved keratin 18 cytoskeletal protein, M30, which is known as an apoptotic marker in residual rectal cancer following preoperative CRT. A total of 72 patients with rectal cancer who had undergone preoperative CRT were enrolled in this study. Immunostaining with M30 cytodeath antibody was performed and the correlation between M30 staining and clinicopathological variables was analyzed. Furthermore, we examined the correlation of M30 staining with the expression of Bax, Bcl-2, Ki67 and PCNA using transcriptional and immunohistochemical analyses. The results showed that 34 (47%) patients were positive for M30 staining. Lack of M30 expression was significantly correlated with advanced T stage, postoperative stage and tumor recurrence (P<0.05). Patients with M30 staining had better recurrence-free survival (RFS) than those without it (P=0.0301). In the immunohistochemical analysis, residual cancer cells with M30 staining lacked Ki67 expression. No significant correlation was observed between M30 positivity and the gene expression of apoptotic and proliferative markers. In conclusion, findings of the present study suggested that the evaluation of M30 expression may be useful in the prediction of tumor recurrence in rectal cancer patients who have been treated with preoperative CRT.

Neither FDG-PET Nor CT can distinguish between a pathological complete response and an incomplete response after neoadjuvant chemoradiation in locally advanced rectal cancer: a prospective study

OBJECTIVE

To prospectively compare the ability of flourodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) to identify a pathological complete response (pCR) in patients with rectal cancer treated by chemoradiation.

BACKGROUND

A major obstacle in pursuing nonoperative management in patients with rectal cancer after chemoradiation is the inability to identify a pCR preoperatively.

METHODS

A total of 121 patients with rectal cancer were prospectively enrolled. FDG-PET scans and helical CT scans were obtained before and after neoadjuvant chemoradiation. Consensus readings of PET and CT scans were used to classify certainty of disease (5-point confidence rating scale). The ability of PET and CT scans to accurately distinguish a pCR (ypT0) from an incomplete response (ypT1-4) was estimated using the area under the receiver operating characteristic curve (AUC).

RESULTS

Of the 121 patients, 26 (21%) had a pCR. PET and CT scans were equally inadequate at distinguishing a pCR from an incomplete response (AUC = 0.64 for both, P = 0.97). Among the 26 patients with a pCR, 14 (54%) and 5 (19%) were classified as complete responders on PET and CT scans, respectively. Among the 95 patients with an incomplete pathological response, 63 (66%) and 90 (95%) were classified as incomplete responders on PET and CT scans, respectively. None of the individual PET parameters, including visual response score, mean standard uptake value (SUVmean), maximum SUV (SUVmax), and total lesion glycolysis, accurately distinguished a pCR (AUCs = 0.57-0.73).

CONCLUSIONS

Neither PET nor CT scans have adequate predictive value to be clinically useful in distinguishing a pCR from an incomplete response and, therefore, should not be obtained for the purpose of attempting to predict a pCR after neoadjuvant chemoradiation for rectal cancer.

Predictive value of (18)FDG PET-CT for tumour response in patients with locally advanced rectal cancer treated by preoperative chemoradiotherapy

PURPOSE

Although (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)FDG PET-CT) is considered a reliable modality for determining tumour response after neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC), the role of (18)FDG PET-CT for predicting pathologic complete response (pCR) remains unclear. The aim of this study was to evaluate whether (18)FDG PET-CT can predict tumour response after CRT in patients with LARC, in terms of downstaging and pCR.

METHODS

Between March 2009 and February 2012, 151 patients with LARC treated with neoadjuvant CRT followed by radical surgery were reviewed retrospectively. Pre-CRT SUVmax (maximum standardized uptake value), post-CRT SUVmax, ΔSUVmax (difference between pre- and post-CRT SUVmax), and RI-SUV (response index) were measured before and after CRT. Univariate and multivariate analyses were used to analyse the association of PET-CT-related parameters and clinical variables, to assess downstaging and pCR.

RESULTS

Downstaging occurred in 48 patients (31.7 %) and pCR in 19 patients (12.5 %). Univariate and multivariate analysis revealed post-CRT SUVmax as a significant factor for prediction of downstaging, with sensitivity of 60.4 %, specificity of 65.0 %, and accuracy of 55.9 %, for a cutoff value of 3.70. Regarding pCR, post-CRT SUVmax was again found as a significant parameter by univariate and multivariate analysis, with sensitivity of 73.7 %, specificity of 63.7 %, and accuracy of 64.9 %, for a cutoff value of 3.55.

CONCLUSIONS

The results indicate that post-CRT SUVmax independently predicts downstaging and pCR. However, the predictive values of post-CRT SUVmax for tumour response after neoadjuvant CRT are too low in sensitivity and specificity to change the treatment plan for 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.

Slug expression inhibits calcitriol-mediated sensitivity to radiation in colorectal cancer

Recently, a reciprocal relationship between calcitriol and epithelial-to-mesenchymal transition has been described. Therefore, we hypothesized that calcitriol (1α,25-dihydroxyvitamin D₃) would enhance radiation sensitivity in colorectal cancer regulated by epithelial mesenchymal transition. Vitamin-D receptor, E-cadherin and vimentin protein as well as E-cadherin, Snail and Slug mRNA levels were assessed in a panel of human colorectal cancer cell lines at baseline and in response calcitriol. We defined cell lines as calcitriol sensitive based on demonstrating an enhanced epithelial phenotype with increased E-cadherin, reduced vimentin and decreased expression of Snail and Slug as well as decreased cellular migration in response to calcitriol. In calcitriol sensitive cells, including DLD-1 and HCT116, 24 h calcitriol pre-treatment enhanced the radiation sensitivity by 2.3- and 2.6-fold, respectively, at 4 Gy (P < 0.05). In contrast, SW620 cells with high baseline mesenchymal features including high Slug and vimentin expression with low E-cadherin expression demonstrated no significant radiation sensitizing response to calcitriol treatment. Similarly, transfection of Slug in the calcitriol sensitive colon cancer cell lines, DLD-1 and HCT 116, completely inhibited the radiation sensitizing effect of calcitriol. Collectively, we demonstrate that calcitriol can enhance the therapeutic effects of radiation in colon cancer cells and Slug expression mitigates this observed effect potentially representing an effective biomarker for calcitriol therapy.

Timing of surgery after long-course neoadjuvant chemoradiotherapy for rectal cancer: a systematic review of the literature

BACKGROUND

Neoadjuvant long-course chemoradiotherapy is commonly used to improve the local control and resectability of locally advanced rectal cancer, with surgery performed after an interval of a number of weeks.

OBJECTIVE

We report an evidence-based systematic review of published data supporting the optimal time to perform surgical resection after long-course neoadjuvant therapy.

DATA SOURCES

A systematic literature search was undertaken of the MEDLINE and Embase electronic databases from 1995 to 2012.

STUDY SELECTION

English language articles were included that compared outcomes following rectal cancer surgery performed at different times after a long course of neoadjuvant radiation-based therapy.

INTERVENTIONS

: Patients received a long course of neoadjuvant therapy followed by radical surgical resection after an interval period.

MAIN OUTCOME MEASURES

The rates of tumor response, R0 resection, sphincter preservation, surgical complications, and disease recurrence were the primary outcomes measured.

RESULTS

Fifteen studies were identified: 1 randomized controlled trial, 1 prospective nonrandomized interventional study, and 13 observational studies. Studies compared time intervals that varied between <5 days and >12 weeks, with a large degree of variation in what the standard interval length was considered to be. Four of the 7 studies that reported rates of pathological complete response identified significantly higher rates with an extended interval between chemoradiotherapy and surgery; 3 of 8 studies demonstrated increased primary tumor downstaging with a longer interval. No significant differences have been consistently demonstrated in rates of surgical complications, sphincter preservation, or long-term recurrence and survival.

LIMITATIONS

Neoadjuvant regimes, indications for neoadjuvant therapy, and time intervals after chemoradiotherapy were heterogeneous between studies; consequently, meta-analysis could not be performed.

CONCLUSIONS

There is limited evidence to support decisions regarding when to resect rectal cancer following chemoradiotherapy. There may be benefits in prolonging the interval between chemoradiotherapy and surgery beyond the 6 to 8 weeks that is commonly practiced. However, outcomes need to be studied further in robust randomized studies.

Locally advanced rectal cancer: diffusion-weighted MR tumour volumetry and the apparent diffusion coefficient for evaluating complete remission after preoperative chemoradiation therapy

OBJECTIVE

To evaluate DW MR tumour volumetry and post-CRT ADC in rectal cancer as predicting factors of CR using high b values to eliminate perfusion effects.

METHODS

One hundred rectal cancer patients who underwent 1.5-T rectal MR and DW imaging using three b factors (0, 150, and 1,000 s/mm(2)) were enrolled. The tumour volumes of T2-weighted MR and DW images and pre- and post-CRT ADC150-1000 were measured. The diagnostic accuracy of post-CRT ADC, T2-weighted MR, and DW tumour volumetry was compared using ROC analysis.

RESULTS

DW MR tumour volumetry was superior to T2-weighted MR volumetry comparing the CR and non-CR groups (P < 0.001). Post-CRT ADC showed a significant difference between the CR and non-CR groups (P = 0.001). The accuracy of DW tumour volumetry (Az = 0.910) was superior to that of T2-weighed MR tumour volumetry (Az = 0.792) and post-CRT ADC (Az = 0.705) in determining CR (P = 0.015). Using a cutoff value for the tumour volume reduction rate of more than 86.8 % on DW MR images, the sensitivity and specificity for predicting CR were 91.4 % and 80 %, respectively.

CONCLUSION

DW MR tumour volumetry after CRT showed significant superiority in predicting CR compared with T2-weighted MR images and post-CRT ADC.

Optimal timing of surgery after neoadjuvant chemoradiation therapy in locally advanced rectal cancer

PURPOSE

The optimal time between neoadjuvant chemoradiotherapy (CRT) and surgery for rectal cancer has been debated. This study evaluated the influence of this interval on oncological outcomes.

METHODS

We compared postoperative complications, pathological downstaging, disease recurrence, and survival in patients with locally advanced rectal cancer who underwent surgical resection <8 weeks (group A, n = 105) to those who had surgery ≥8 weeks (group B, n = 48) after neoadjuvant CRT.

RESULTS

Of 153 patients, 117 (76.5%) were male and 36 (23.5%) were female. Mean age was 57.8 years (range, 28 to 79 years). There was no difference in the rate of sphincter preserving surgery between the two groups (group A, 82.7% vs. group B, 77.6%; P = 0.509). The longer interval group had decreased postoperative complications, although statistical significance was not reached (group A, 28.8% vs. group B, 14.3%; P = 0.068). A total of 111 (group A, 75 [71.4%] and group B, 36 [75%]) patients were downstaged and 26 (group A, 17 [16.2%] and group B, 9 [18%]) achieved pathological complete response (pCR). There was no significant difference in the pCR rate (P = 0.817). The longer interval group experienced significant improvement in the nodal (N) downstaging rate (group A, 46.7% vs. group B, 66.7%; P = 0.024). The local recurrence (P = 0.279), distant recurrence (P = 0.427), disease-free survival (P = 0.967), and overall survival (P = 0.825) rates were not significantly different.

CONCLUSION

It is worth delaying surgical resection for 8 weeks or more after completion of CRT as it is safe and is associated with higher nodal downstaging rates.

Phase II trial of preoperative radiochemotherapy with concurrent bevacizumab, capecitabine and oxaliplatin in patients with locally advanced rectal cancer

BACKGROUND

Preoperative radiochemotherapy (RCT) with 5-FU or capecitabine is the standard of care for patients with locally advanced rectal cancer (LARC). Preoperative RCT achieves pathological complete response rates (pCR) of 10-15%. We conducted a single arm phase II study to investigate the feasibility and efficacy of addition of bevacizumab and oxaliplatin to preoperative standard RCT with capecitabine.

METHODS

Eligible patients had LARC (cT3-4; N0/1/2, M0/1) and were treated with preoperative RCT prior to planned surgery. Patients received conventionally fractionated radiotherapy (50.4 Gy in 1.8 Gy fractions) and simultaneous chemotherapy with capecitabine 825 mg/m2 bid (d1-14, d22-35) and oxaliplatin 50 mg/m2 (d1, d8, d22, d29). Bevacizumab 5 mg/kg was added on days 1, 15, and 29. The primary study objective was the pCR rate.

RESULTS

70 patients with LARC (cT3-4; N0/1, M0/1), ECOG < 2, were enrolled at 6 sites from 07/2008 through 02/2010 (median age 61 years [range 39-89], 68% male). At initial diagnosis, 84% of patients had clinical stage T3, 62% of patients had nodal involvement and 83% of patients were M0. Mean tumor distance from anal verge was 5.92 cm (± 3.68). 58 patients received the complete RCT (full dose RT and full dose of all chemotherapy). During preoperative treatment, grade 3 or 4 toxicities were experienced by 6 and 2 patients, respectively: grade 4 diarrhea and nausea in one patient (1.4%), respectively, grade 3 diarrhea in 2 patients (3%), grade 3 obstipation, anal abscess, anaphylactic reaction, leucopenia and neutropenia in one patient (1.4%), respectively. In total, 30 patients (46%) developed postoperative complications of any grade including one gastrointestinal perforation in one patient (2%), wound-healing problems in 7 patients (11%) and bleedings in 2 patients (3%). pCR was observed in 12/69 (17.4%) patients. Pathological downstaging (ypT < cT and ypN ≤ cN) was achieved in 31 of 69 patients (44.9%). All of the 66 operated patients had a R0 resection. 47 patients (68.1%) underwent sphincter preserving surgery.

CONCLUSIONS

The addition of bevacizumab and oxaliplatin to RCT with capecitabine was well tolerated and did not increase perioperative morbidity or mortality. However, the pCR rate was not improved in comparison to other trials that used capecitabine or capecitabine/oxaliplatin in preoperative radiochemotherapy.

Prognosis factors for recurrence in patients with locally advanced rectal cancer preoperatively treated with chemoradiotherapy and adjuvant chemotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision has improved the outcome of locally advanced rectal carcinoma.

OBJECTIVE

The aim of this study was to identify independent prognosis factors of disease recurrence in a group of patients treated with this approach.

DESIGN AND PATIENTS

This study was retrospective in design. Data from patients with locally advanced rectal cancer who had completed treatment from 2000 to 2010 were reviewed.

SETTINGS

The analysis was performed in a tertiary referral center.

MAIN OUTCOME MEASURES

The primary outcomes measured were the recurrence risk factors.

RESULTS

The cohort consisted of 228 patients; 69.3% of them were men, and median age was 59 years. Stage III rectal cancer was found in 64.9% of patients. The most frequently administered therapy was concurrent capecitabine, oxaliplatin, and 7-field radiotherapy, followed by 3-field radiotherapy and fluoropyrimidines. After a median follow-up of 49 months, 23.7% of the patients experienced disease recurrence: 2.6% had local recurrence, 21.1% had distant metastases, and 0.5% had both. Factors significantly correlated with recurrence risk in multivariate logistic regression were y-pathological stage (III vs I/II: OR = 2.51), tumor regression grade (1/2 vs 3+/4: OR = 3.34; 3 vs 3+/4: OR = 1.20), and low rectal location (OR = 2.36). The only independent prognosis factor for liver metastases was tumor regression grade (1/2 vs 3+/4: OR = 4.67; 3 vs 3+/4: OR = 1.41), whereas tumor regression grade (1-2 vs 3+/4: OR = 5.5; 3 vs 3+/4: OR = 1.84), low rectal location (OR = 3.23), and previous liver metastasis (OR = 7.73) predicted lung recurrence.

LIMITATIONS

This is a single institutional experience, neoadjuvant combined therapy is not homogeneous, and the analysis has been performed in a retrospective manner.

CONCLUSIONS

Patients with low third locally advanced rectal cancer with a poor response to neoadjuvant chemoradiotherapy (high y-pathological stage or low tumor regression grade) are at high risk of recurrence. Intense surveillance and the design of alternative therapeutic approaches aimed to lower the distant failure rate seem warranted.