Revised tumor and node categorization for rectal cancer based on surveillance, epidemiology, and end results and rectal pooled analysis outcomes

Proposal of new classification for stage III colon cancer based on the lymph node ratio: analysis of 4,172 patients from multi-institutional database in Japan

BACKGROUND

We retrospectively examined the optimal lymph node ratio (LNR) cutoff value and attempted to construct a new classification using the LNR in stage III colon cancer.

METHODS

The clinical and pathological data of 4,172 patients with histologically proven lymph node metastasis who underwent curative surgery for primary colon cancer at multiple institutions between 1995 and 2004 were derived from the multi-institutional database of the Japanese Society for Cancer of the Colon and Rectum (JSCCR). We determined independent prognostic factors and constructed a new classification using these factors. Finally, we compared the discriminatory ability between the new classification and the TNM seventh edition (TNM 7th) classification.

RESULTS

The optimal LNR cutoff value was 0.18. Multivariate analysis revealed that year of surgery, age, gender, histological type, TNM 7th T category, lymphatic invasion, venous invasion, TNM 7th N category, and LNR were found to be significant independent prognostic factors. We attempted to construct a new classification based on the combination of TNM 7th T category and LNR. As a result, the cancer-specific survivals were well stratified (P < .0001). According to the Akaike's information criteria value, the new classification was judged to be superior to the TNM 7th classification with respect to both a better fit and lower complexity.

CONCLUSIONS

The optimal LNR cutoff value that was found using the Japanese multi-institutional database and the new classification using LNR are considered to be extremely significant. Therefore, these findings strongly support the application of LNR in the stage classification in stage III colon cancer.

Multivariate analysis of prognostic factors for patients with colon carcinoma

AIM: To investigate the prognostic factors for colon carcinoma by analyzing its clinical and pathological characteristics.

METHODS: We retrospectively reviewed the demographic, clinical, histopathological, and laboratory data for consecutive patients with colon cancer who underwent curative surgery alone from July 2007 to May 2010 at Peking University Cancer Hospital. Unvaried and multivariate analyses were conducted to identify prognostic factors for colon carcinoma.

RESULTS: A total of 226 valid cases were reviewed in this study, and their 3-year overall survival rate was 81.9%. Univariate analysis showed that preoperative CEA level > 5 ng/mL, poor differentiation, age < 40, blood transfusion, higher T stage, higher N stage, metastasis and lymphatic vessel invasion were poor prognostic factors for patients with colon cancer (P < 0.05). Multivariate analysis found that preoperative CEA level (P = 0.017), higher N stage (P = 0.005), poor differentiation (P = 0.002), and higher M stage (P = 0.000) were the independent prognostic factors for colon carcinoma.

CONCLUSION: Based on the prognostic risk factors such as preoperative CEA level, poor differentiation, higher N stage and metastasis, more accurate risk stratification can be conducted in patients with colon cancer. Patients with such risk factors should be considered as candidates for receiving more intensive treatment and surveillance.

TNM staging of colorectal cancer should be reconsidered by T stage weighting

AIM: To verify that the T stage has greater weight than the N stage in the staging of colorectal cancer.

METHODS: Open data from the Surveillance, Epidemiology, and End Results program were reviewed and analyzed according to the T stage, N stage, and patients’ observed survival (OS). The relative weights of the T and N stages were calculated by multiple linear regressions based on their impact on survival. Risk scores for 25 TN categories were then calculated from the T and N stage relative weights, and a rearranged tumor node metastasis (TNM) staging system was proposed via a cluster analysis of the TN scores.

RESULTS: Both T and N stages significantly affect the OS of patients with colorectal cancer. Moreover, the T stage has greater weight than the N stage in the TNM staging system of colorectal cancer. For colon cancer, the relative T and N stage weights were 0.58 and 0.42, respectively, and for rectal cancer, the relative T and N stage weights were 0.61 and 0.39, respectively. On the basis of cluster analysis of the TN scores, T1N1a was classified to stage I, and T2N1a-1b and T1N1b-2a were classified to stage II in our revised TNM staging system for both colon and rectal cancer. For colon cancer, T4bN0 was classified to stage IIIa, but for rectal cancer, it was classified to stage IIIb.

CONCLUSION: As the T stage affects colorectal cancer survival more significantly than the N stage, the TNM staging should be revised by relative T stage weight.

Capecitabine and oxaliplatin in the preoperative multimodality treatment of rectal cancer: surgical end points from National Surgical Adjuvant Breast and Bowel Project trial R-04

PURPOSE

The optimal chemotherapy regimen administered concurrently with preoperative radiation therapy (RT) for patients with rectal cancer is unknown. National Surgical Adjuvant Breast and Bowel Project trial R-04 compared four chemotherapy regimens administered concomitantly with RT.

PATIENTS AND METHODS

Patients with clinical stage II or III rectal cancer who were undergoing preoperative RT (45 Gy in 25 fractions over 5 weeks plus a boost of 5.4 Gy to 10.8 Gy in three to six daily fractions) were randomly assigned to one of the following chemotherapy regimens: continuous intravenous infusional fluorouracil (CVI FU; 225 mg/m(2), 5 days per week), with or without intravenous oxaliplatin (50 mg/m(2) once per week for 5 weeks) or oral capecitabine (825 mg/m(2) twice per day, 5 days per week), with or without oxaliplatin (50 mg/m(2) once per week for 5 weeks). Before random assignment, the surgeon indicated whether the patient was eligible for sphincter-sparing surgery based on clinical staging. The surgical end points were complete pathologic response (pCR), sphincter-sparing surgery, and surgical downstaging (conversion to sphincter-sparing surgery).

RESULTS

From September 2004 to August 2010, 1,608 patients were randomly assigned. No significant differences in the rates of pCR, sphincter-sparing surgery, or surgical downstaging were identified between the CVI FU and capecitabine regimens or between the two regimens with or without oxaliplatin. Patients treated with oxaliplatin experienced significantly more grade 3 or 4 diarrhea (P < .001).

CONCLUSION

Administering capecitabine with preoperative RT achieved similar rates of pCR, sphincter-sparing surgery, and surgical downstaging compared with CVI FU. Adding oxaliplatin did not improve surgical outcomes but added significant toxicity. The definitive analysis of local tumor control, disease-free survival, and overall survival will be performed when the protocol-specified number of events has occurred.

High-resolution analysis of DNA copy number alterations in rectal cancer: correlation with metastasis, survival, and mRNA expression

BACKGROUND AND PURPOSE

This study aimed to determine the candidate genes and chromosomal imbalances capable of predicting occurrences of metastasis in patients with rectal cancer.

PATIENTS AND METHODS

Fresh frozen tumor tissues from 80 patients with rectal cancer were prospectively collected and analyzed using Affymetrix HG-U133 Plus 2.0 gene expression arrays and high-resolution Illumina single-nucleotide polymorphism (SNP) arrays. Endpoints of the study were metastasis-free survival (MFS) and cancer-specific survival (CSS).

RESULTS

The median follow-up was 102 months (1-146). Deletions of 8p and 1p36-35 correlated with worse MFS (p = 0.005 and p = 0.01, respectively) and CSS (p = 0.001 and p = 0.01, respectively). Multivariate analysis identified 8p deletion as an independent prognostic factor for MFS (p = 0.04) and CSS (p = 0.003); 97 genes located on the 8p chromosome were significantly underexpressed in tumors with 8p deletion.

CONCLUSION

This study shows for the first time in rectal cancer an independent correlation of 8p deletion with MFS and CSS and highlights potential new tumor suppressor genes.

Multimodal imaging evaluation in staging of rectal cancer

Rectal cancer is a common cancer and a major cause of mortality in Western countries. Accurate staging is essential for determining the optimal treatment strategies and planning appropriate surgical procedures to control rectal cancer. Endorectal ultrasonography (EUS) is suitable for assessing the extent of tumor invasion, particularly in early-stage or superficial rectal cancer cases. In advanced cases with distant metastases, computed tomography (CT) is the primary approach used to evaluate the disease. Magnetic resonance imaging (MRI) is often used to assess preoperative staging and the circumferential resection margin involvement, which assists in evaluating a patient’s risk of recurrence and their optimal therapeutic strategy. Positron emission tomography (PET)-CT may be useful in detecting occult synchronous tumors or metastases at the time of initial presentation. Restaging after neoadjuvant chemoradiotherapy (CRT) remains a challenge with all modalities because it is difficult to reliably differentiate between the tumor mass and other radiation-induced changes in the images. EUS does not appear to have a useful role in post-therapeutic response assessments. Although CT is most commonly used to evaluate treatment responses, its utility for identifying and following-up metastatic lesions is limited. Preoperative high-resolution MRI in combination with diffusion-weighted imaging, and/or PET-CT could provide valuable prognostic information for rectal cancer patients with locally advanced disease receiving preoperative CRT. Based on these results, we conclude that a combination of multimodal imaging methods should be used to precisely assess the restaging of rectal cancer following CRT.

Role of pelvic exenteration in the management of locally advanced primary and recurrent rectal cancer

AIM

A review of a single-centre experience of pelvic exenteration as a treatment modality for patients with locally advanced primary and recurrent rectal cancer. The perioperative outcomes, morbidity and long term oncological outcomes are reviewed.

MATERIALS & METHODS

Patients undergoing pelvic exenterations for recurrent and locally advanced rectal cancer between 1 January 2006 and 1 August 2012 were identified from a prospective database. All patients underwent pre-operative staging investigations with computed tomography (CT) scan of chest, abdomen and pelvis and pelvic magnetic resonance imaging (MRI). Patients with locally advanced primary rectal cancer were counselled for pre-operative chemoradiation. Structures such as the urinary bladder and female reproductive organs were resected en bloc where indicated with the lesion. Urological or plastic reconstructions were employed where indicated. The primary outcome measured was overall survival and secondary outcomes measured were time to local recurrence (LR) and systemic recurrence. Disease-free survival was examined by the Kaplan-Meier Method (Fig. 1).

RESULTS

Pelvic exenterations were performed in 13 patients with a median age of 59 (range 26-81). The rate of major post-operative complications was 8% (n = 1), where the patient had anastomotic leakage. There were no mortalities in the perioperative period. All patients were operated with curative intent and negative circumferential margins were shown in 9 out of 13 patients (70%). The DFS was 19.4 and the OS was 22.5 months.

CONCLUSION

An aggressive approach with en bloc resection of organs involved provides survival benefit to patients with locally advanced primary and recurrent rectal cancer with an acceptable morbidity profile.

Positron emission tomography/computed tomography for optimized colon cancer staging and follow up

OBJECTIVES

Optimal management of colon cancer (CC) requires detailed assessment of extent of disease. This study prospectively investigates the diagnostic accuracy of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (PET/CT) for staging and detection of recurrence in primary CC.

MATERIAL AND METHODS

PET/CT for preoperative staging was performed in 66 prospectively included patients with primary CC. Diagnostic accuracy for PET/CT and CT was analyzed. In addition to routine follow up, 42 stages I-III CC patients had postoperative PET/CT examinations every 6 months for 2 years. Serological levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), carcinoembryonic antigen, and liberated domain I of urokinase plasminogen activator receptor were analyzed.

RESULTS

Accuracy for tumor, nodal, and metastases staging by PET/CT were 82% (95% confidence interval [CI]: 70; 91), 66% (CI: 51; 78), and 89% (CI: 79; 96); for CT the accuracy was 77% (CI: 64; 87), 60% (CI: 46; 73), and 69% (CI: 57; 80). Cumulative relapse incidences for stages I-III CC at 6, 12, 18, and 24 months were 7.1% (CI: 0; 15); 14.3% (CI: 4; 25); 19% (CI: 7; 31), and 21.4% (CI: 9; 34). PET/CT diagnosed all relapses detected during the first 2 years. High preoperative TIMP-1 levels were associated with significant hazards toward risk of recurrence and shorter overall survival.

CONCLUSIONS

This study indicates PET/CT as a valuable tool for staging and follow up in CC. TIMP-1 provided prognostic information potentially useful in selection of patients for intensive follow up.

The validity of predicting prognosis by the lymph node ratio in node-positive colon cancer

BACKGROUND/AIMS

Because the TNM system disregards the number of lymph nodes dissected and inter-individual differences exist in the number of regional lymph nodes, the lymph node ratio (LNR), which is estimated by dividing the number of metastatic lymph nodes by the number of dissected lymph nodes, has been proposed as a prognostic factor in recent years. The purpose of the present study is to examine the validity of predicting prognosis using the LNR in node-positive colon cancer.

METHODS

Three hundred and eleven patients with lymph node metastases who underwent curative surgery for colon cancer at our department between 1992 and 2005 were enrolled. Univariate and multivariate analyses were performed to evaluate the relationship between clinicopathological factors and prognosis.

RESULTS

Among the patients with ≥12 dissected lymph nodes, differentiation, invasion depth and TNM N category were found to be significant independent prognostic factors. On the other hand, among the patients with ≤11 dissected lymph nodes, differentiation and the LNR were found to be significant independent prognostic factors.

CONCLUSION

Among the patients with ≤11 dissected lymph nodes, LNR was a significant independent prognostic factor.

Anal carcinoma: impact of TN category of disease on survival, disease relapse, and colostomy failure in US Gastrointestinal Intergroup RTOG 98-11 phase 3 trial

PURPOSE

The long-term update of US GI Intergroup RTOG 98-11 anal cancer trial found that concurrent chemoradiation (CCRT) with fluorouracil (5-FU) plus mitomycin had a significant impact on disease-free survival (DFS) and overall survival (OS) compared with induction plus concurrent 5-FU plus cisplatin. The intent of the current analysis was to determine the impact of tumor node (TN) category of disease on survival (DFS and OS), colostomy failure (CF), and relapse (local-regional failure [LRF] and distant metastases [DM]) in this patient group.

METHODS AND MATERIALS

DFS and OS were estimated univariately by using the Kaplan-Meier method, and 6 TN categories were compared by the log-rank test (T2N0, T3N0, T4N0, T2N1-3, T3N1-3, and T4N1-3). Time to relapse and colostomy were estimated by the cumulative incidence method, and TN categories were compared using Gray's test.

RESULTS

Of 682 patients, 620 were analyzable for outcomes by TN category. All endpoints showed statistically significant differences among the TN categories of disease (OS, P<.0001; DFS, P<.0001; LRF, P<.0001; DM, P=.0011; CF, P=.01). Patients with the poorest OS, DFS, and LRF outcomes were those with T3-4N-positive (+) disease. CF was lowest for T2N0 and T2N+ (11%, 11%, respectively) and worst for the T4N0, T3N+, and T4N+ categories (26%, 27%, 24%, respectively).

CONCLUSIONS

TN category of disease has a statistically significant impact on OS, DFS, LRF, DM, and CF in patients treated with CCRT and provides excellent prognostic information for outcomes in patients with anal carcinoma. Significant challenges remain for patients with T4N0 and T3-4N+ categories of disease with regard to survival, relapse, and CF and lesser challenges for T2-3N0/T2N+ categories.

A nodal positivity constant: new perspectives in lymph node evaluation and colorectal cancer

PURPOSE

To date, associations between the number of lymph nodes evaluated, staging, and survival have been examined in the context of large population-based studies conducted by a small number of investigators. Therefore, although high-quality data are available, perspective is lacking.

METHODS

Studies for this paper were identified by searches of Medline, Scopus, PubMed, and manual searching of references from articles, using the search terms ''colorectal cancer'', ''nodal status'' and ''lymph node''.

RESULTS

It is clear that survival benefit increases with the increasing number of lymph nodes harvested. Despite this observation, there has been no significant increase in the proportion of node-positive cancers over the past two decades.

CONCLUSION

The nodal positivity rate for colorectal cancer consistently approximates 40 % across a wide range of studies internationally, a phenomenon that has not previously been recognized in the literature. We review the evidence and introduce the concept of a nodal positivity constant.

Future directions in combined modality therapy for rectal cancer: reevaluating the role of total mesorectal excision after chemoradiotherapy

Most patients who develop rectal cancer present with locoregionally advanced (T3 or node-positive) disease. The standard management of locoregionally advanced rectal cancer is neoadjuvant concurrent chemoradiotherapy (nCRT), followed by radical resection (low-anterior resection or abdominoperineal resection with total mesorectal excision). Approximately 15% of patients can have a pathologic complete response (pCR) at the time of surgery, indicating that some patients can have no detectable residual disease after nCRT. The actual benefit of surgery in this group of patients is unclear. It is possible that omission of surgery in these patients, termed selective nonoperative management, can limit the toxicities associated with standard, multimodal combined modality therapy without compromising disease control. In this review, we discuss the clinical experiences to date using selective nonoperative management and various attempts at escalation of nCRT to improve the number of patients who have a pCR. We also explore several clinical, laboratory, imaging, histopathologic, and genetic biomarkers that have been tested as tools to predict which patients are most likely to have a pCR after nCRT.

Selecting patients with locally advanced rectal cancer for neoadjuvant treatment strategies

Rectal cancer remains a significant problem worldwide. Outcomes vary significantly according to the stage of disease and prognostic factors, including the distance of the tumor from the circumferential resection margin. Accurate staging, including high-resolution magnetic resonance imaging, allows stratification of patients into low-, moderate-, and high-risk disease; this information can be used to inform multidisciplinary team decisions regarding the role of neoadjuvant therapy. Both neoadjuvant short-course radiotherapy and long-course chemoradiation reduce the risk of local recurrence compared with surgery alone, but they have little impact on survival. Although there remains a need to reduce overtreatment of those patients at moderate risk, evaluation of intensified regimens for those with high-risk disease is still required to reduce distant failure rates and improve survival in these patients with an otherwise poor prognosis.

Prognostic impact of the metastatic lymph node ratio on survival in rectal cancer

Purpose

Lymph-node metastasis is the most important predictor of survival in stage III rectal cancer. The number of metastatic lymph nodes may vary depending on the level of specimen dissection and the total number of lymph nodes harvested. The aim of this study was to evaluate whether the lymph node ratio (LNR) is a prognostic parameter for patients with rectal cancer.

Methods

A retrospective review of a database of rectal cancer patients was performed to determine the effect of the LNR on the disease-free survival (DFS) and the overall survival. Of the total 228 patients with rectal cancer, 55 patients with stage III cancer were eligible for analysis. Survival curves were estimated using the Kaplan-Meier method. Cox regression analyses, after adjustments for potential confounders, were used to evaluate the relationship between the LNR and survival.

Results

According to the cutoff point 0.15 (15%), the 2-year DFS was 95.2% among patients with a LNR < 0.15 compared with 67.6% for those with LNR ≥ 0.15 (P = 0.02). In stratified and multivariate analyses adjusted for age, gender, histology and tumor status, a higher LNR was independently associated with worse DFS.

Conclusion

This study showed the prognostic significance of ratio-based staging for rectal cancer and may help in developing better staging systems. LNR 0.15 (15%) was shown to be a cutoff point for determining survival and prognosis in rectal cancer cases.

Prognostic significance of thymidylate synthase polymorphisms in rectal cancer patients treated with neoadjuvant chemoradiotherapy

AIM

There is a lack of prognostic factors of preoperative chemoradiation for locally advanced rectal cancer. Thymidylate synthase (TS) is the most important target of 5-fluorouracil; three main genetic polymorphisms of TS have been described. We analysed the prognostic value of these in patients with locally advanced rectal cancer treated with fluoropyrimidine-based chemoradiation.

METHOD

Ninety-nine patients treated between November 2001 and March 2009 were included. All were treated by radiotherapy (5040 cGy) and concomitant fluoropyrimidine-based chemotherapy. Three polymorphisms were analysed: (i) a double (2R) or triple (3R) repeat of a 28 base pair (bp) tandem sequence upstream of the ATG codon initiation site in the 5'-terminal regulatory region, (ii) a functional G > C single nucleotide polymorphism present in the second repeat of the 3R alleles and (iii) a 6 bp deletion at nucleotide 1494 in the 3'-untranslated region. DNA was extracted from paraffin-embedded core biopsies taken from the tumour and the genotype was analysed using polymerase chain reaction restriction fragment length polymorphism.

RESULTS

The 6 bp polymorphism was significantly associated with disease-free survival (+ 6 bp/+ 6 bp vs-6 bp/-6 bp, P = 0.032 logistic regression). No differences were found in disease-free survival according to the other polymorphisms studied. No relationship was observed between the different TS genotypes and pathological regression.

CONCLUSION

The study suggests that the TS 6 bp polymorphism may be a predictor of disease-free survival in patients with locally advanced rectal cancer treated with fluoropyrimidine-based chemoradiation.

Is the prediction of prognosis not improved by the seventh edition of the TNM classification for colorectal cancer? Analysis of the surveillance, epidemiology, and end results (SEER) database

BACKGROUND

Whether the 7th edition of American Joint Committee on Cancer (AJCC) TNM staging system (AJCC-7) is a successful revision remains debatable. We aimed to compare the predictive capacity of the AJCC-7 for colorectal cancer with the 6th edition of the AJCC TNM staging system (AJCC-6).

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) dataset consisting of 158,483 records was used in this study. We evaluated the predictive capacity of the two editions of the staging system using Harrell's C index and Bayesian Information Criterion (BIC).

RESULTS

There was a significant prognostic difference between patients at stage IIB and IIC (P < 0.001). Stage III patients with similar prognoses were adequately sub-grouped in the same stage according to AJCC-7. The Harrell's C index revealed a value of 0.7692 for AJCC-7, which was significantly better than 0.7663 for AJCC-6 (P < 0.001). BIC analysis provided consistent results (P < 0.001).

CONCLUSIONS

This study demonstrates that AJCC-7 is superior to the AJCC-6 staging system in predictive capacity.

Should isolated peritoneal carcinomatosis from colorectal cancer be sub-classified into stage IVB in era of modern chemotherapy?

BACKGROUND

According to the 7th edition of the TNM staging system, stage IV metastatic colorectal cancer (CRC) at the time of initial diagnosis is sub-classified into stage IVA or IVB disease. Peritoneal carcinomatosis (PC), considered to have a dismal prognosis, is exclusively sub-classified into stage IVB, even though other metastases to a sole organ are sub-classified into stage IVA, which is considered to be associated with better survival. This retrospective study was undertaken to investigate the overall survival in metastatic CRC patients, focusing on PC patients.

METHODS

We reviewed data on patients with metastatic CRC at initial diagnosis surgically treated between January 2006 and June 2011. A survival analysis was performed paying special attention to PC and sub-classifying patients with PC into three categories according to metastatic sites.

RESULTS

There were 69 stage IVA patients (IVA group) and 83 stage IVB. Among stage IVB patients, 20 had isolated PC (PC-I group), 28 had PC with one or more other sites of metastasis (PC-II group), and 35 had at least 2 metastatic without peritoneal involvement (NPC group). Of 152 stage IV patients, 132 (87 %) underwent resection of the primary tumor and 19 (12 %) underwent radical resection of metastatic disease with microscopic free margins (R0 resection) including 5/20 (25 %) patients in the PC1 group. A total of 139 patients received oxaliplatin-based chemotherapy in a palliative (n = 125), neoadjuvant (n = 3), or adjuvant setting after R0 resection (n = 11). Compared with 36.6 months in the PC-I group, median survival was 32.5 months (P = 0.48) in the IVA group, 14.7 months (P = 0.07) in the PC-II group, and 12.9 months (P < 0.01) in the NPC group.

CONCLUSIONS

The sub-classification of isolated PC into stage IVA instead of IVB might be more appropriate in the era of modern chemotherapy. Further investigation is warranted.

Prognostic significance of apical lymph node metastasis in patients with node-positive rectal cancer

AIM

The aim of this study was to assess the effect of apical lymph node (APN) metastasis in predicting prognosis in curatively treated node-positive rectal cancer. We also investigated the relationship between APN metastasis and the total number of metastatic lymph nodes.

METHOD

A retrospective study was performed of 510 curatively treated patients with node-positive rectal cancer. Clinicopathological variables, including APN status, were assessed in univariate and multivariate analyses. The prognostic significance of APN status in predicting patient outcomes and the relationship between APN status and American Joint Committee on Cancer (AJCC) N stage were analysed.

RESULTS

At a median follow up of 47 months, the 5-year local recurrence (LR) rate, the disease-free survival (DFS) rate and the overall survival (OS) rate were 18.3%, 55.5% and 58.8%, respectively. The 5-year OS rate was 69.6% for patients with no metastasis in APNs (APN(-)) and 40.8% for patients with metastasis in APNs (APN(+)). DFS and OS for patients with undetermined APN status were between those for APN(-) and APN(+). Subgroup analysis gave a 5-year OS rate of 48.7% in Stage N1 patients with APN(+) and 58.8% for Stage N2 patients with APN(-) (P = 0.0004).

CONCLUSION

APN metastasis is an important prognostic factor in node-positive rectal cancer, which provides additional survival-related prognostic classification irrespective of N stage. As the APN is usually outside the radiation field, in the era of multidisciplinary treatment its assessment should be incorporated into prognostic evaluation of rectal cancer.

TNM staging of colorectal carcinoma: issues and caveats

The TNM staging system of the American Joint Committee on Cancer and the Union for International Cancer Control provides the most reliable guidelines for the prognostication and treatment of colorectal carcinoma. However, issues and caveats exist in the application of this system, mostly relating to the definition of the staging parameters and the pathologic interpretation of the gross and microscopic findings of the resected specimens. This article highlights some of the major issues in both areas. First, it assesses the definition of selected staging parameters, including pTis, pT4a versus pT4b, tumor deposits/N1c, ypT/ypN, and the TNM for rectal versus anal carcinoma. Second, it discusses major problematic areas in the pathologic interpretation of "pseudoinvasion" versus true invasion, deep pT2 versus superficial pT3, serosal involvement, radial margin, total mesorectal excision specimens, and postneoadjuvant chemoradiation rectal resections. The article also provides a brief discussion about some of the major adjunct histopathologic prognostic factors, such as medullary-type histology and tumor differentiation.

Examining stage IIB survival in a population-based cohort of patients with colorectal cancer

BACKGROUND

In Nova Scotia, Canada, a previous study of colorectal cancer (CRC) cases diagnosed between January 1, 2001, and December 31, 2005, found that patients with stage IIB CRC had similar 5-year overall survival (OS) to those with stage IIIC cancer. This study sought to examine factors contributing to the observed stage IIB outcome, specifically nodal harvest, receipt of chemotherapy, and use of a new coding system to derive stage.

METHODS

The provincial cancer registry identified all CRC cases diagnosed during the study period and staged this cohort using the Collaborative Stage (CS) Data Collection System. All patients with stage II and III cancer in the cohort were examined. Kaplan-Meier (KM) survival curves compared 5-year OS for patients with stage IIB cancer based on the factors of interest, and compared patients with stage IIB cancer to those with stage IIA and III cancer.

RESULTS

OS for patients with stage IIB cancer (n = 187) was 44.7%, and differed depending on adequacy of nodal harvest (P = .005) and whether pathological or clinical/mixed evidence was used to derive stage (P = .013). Pathologically-staged patients with stage IIB cancer who had adequate nodal harvest had marginally improved OS compared to pathologically-staged patients who had inadequate nodal harvest (P = .07), and improved survival compared to patients with clinical/mixed stage (P = .004). Pathologically-staged patients with stage IIB cancer with adequate nodal harvest demonstrated similar 5-year OS to those with stage IIA and III cancer (P = .52 and P = .25, respectively). Cox proportional hazards models supported these findings.

CONCLUSIONS

The inclusion of clinical/mixed evidence into staging classification and, perhaps to a lesser extent, the adequacy of nodal harvest appear to contribute to the observed worse survival for patients with stage IIB versus stage III cancer.

Gene expression profiles in stages II and III colon cancers: application of a 128-gene signature

PURPOSE

A 128-gene signature has been proposed to predict outcome in patients with stages II and III colorectal cancers. In the present study, we aimed to reproduce and validate the 128-gene signature in external and independent material.

METHODS

Gene expression data from the original material were retrieved from the Gene Expression Omnibus (GEO) (n = 111) in addition to a Danish data set (n = 37). All patients had stages II and III colon cancers. A Prediction Analysis of Microarray classifier, based on the 128-gene signature and the original training set of stage I (n = 65) and stage IV (n = 76) colon cancers, was reproduced. The stages II and III colon cancers were subsequently classified as either stage I-like (good prognosis) or stage IV-like (poor prognosis) and assessed by the 36 months cumulative incidence of relapse.

RESULTS

In the GEO data set, results were reproducible in stage III, as patients predicted to be stage I-like had a significant lower risk of relapse than patients predicted as stage IV-like (P = 0.04, Gray test). Results were not reproducible in stage II patients (P > 0.05, Gray test). In the Danish data set, two of four stage III patients with relapse were correctly predicted as stage IV-like, and the remaining patients were predicted as stage I-like and unclassifiable, respectively. Stage II patients could not be stratified.

CONCLUSIONS

The 128-gene signature showed reproducibility in stage III colon cancer, but could not predict recurrence in stage II. Individual patient predictions in an independent Danish material were unsatisfactory. Additional validation in larger cohorts is warranted.

Towards a "Lyon molecular signature" to individualize the treatment of rectal cancer. Prognostic analysis of a prospective cohort of 94 rectal cancers T1-2-3 Nx MO to be the basis of a molecular signature

PURPOSE

In 1998 a translational research was initiated in Lyon aiming at identifying a prognostic "biomolecular signature" in rectal cancer. This paper presents the clinical outcome of the patients included in this study.

PATIENTS AND METHODS

A total of 94 patients were included between 1998 and 2001. A staging with rectoscopy and biopsies was performed before treatment. In case of surgery, the operative specimen was analysed to evaluate the pathological response. There were two types of treatment: neoadjuvant radiotherapy (with or without concurrent chemotherapy) followed by surgery (76 cases) and radiotherapy alone with 'contactherapy' often associated with external beam radiotherapy (18 patients).

RESULTS

The patients had a mean age of 63years. Stage was T1: 4, T2: 24, T3: 65 and T4: 1. The overall survival of the 94 patients was 62% at 8years with a rate of distant metastases of 29%. Rate of local recurrence at 8years was 6% in the neoadjuvant group and 16% in the radiotherapy group with an overall 8years survival in both groups respectively: 64% and 53%. There was a trend towards more metastases in cT3, tumour diameter above 4cm, circumferential extension. There was a significant increase in the risk of metastases for ypT3, ypN1-2 and Dworak score 1-2-3. In multivariate analysis ypT3 was significantly associated with a high rate of metastases (55%; P=0.0003).

CONCLUSION

The rate of distant metastases is a major prognostic factor. These clinical results will serve as the base line to identify a "biomolecular signature" which could complement the TN(M) classification.

Neoadjuvant chemoradiation followed by interstitial prostate brachytherapy for synchronous prostate and rectal cancer

PURPOSE

To describe outcomes with the use of neoadjuvant pelvic chemoradiation followed by prostate interstitial brachytherapy for the treatment of synchronous prostate and rectal cancers.

METHODS AND MATERIALS

An Internal Review Board approved retrospective review was undertaken of 4 patients with synchronous prostate and rectal cancer treated between 2006 and 2008. Patients underwent pelvic chemoradiation followed by prostate brachytherapy, then low anterior resection of the rectum with diverting loop ileostomy and adjuvant chemotherapy. Follow-up evaluation included imaging and laboratory analysis of cancer markers in addition to routine interval history and physical examination.

RESULTS

At 38-62 months postdiagnosis (24-53 months post-treatment), 6 of 8 cancers remained without evidence of relapse. One patient had rising carcinoembryonic antigen levels but no clinically evident rectal cancer relapse; another developed bony metastasis of his high-risk prostate cancer. Three patients experienced grade 1-2 treatment-related toxicity; one patient had grade 3 gastrointestinal toxicity from radiation and surgery, which precluded his receiving adjuvant chemotherapy and ileostomy reversal.

CONCLUSIONS

Chemoradiation followed by prostate brachytherapy, surgery, and adjuvant chemotherapy may be utilized to manage patients with synchronous prostate and rectal cancers.

Impact and prognostic implications of colon cancers stage II sub-classification through the years

PURPOSE

According to the American Joint Committee on Cancer (AJCC) 7th edition, T4 colon cancers have been sub-divided into T4a and T4b, resulting in a stage II sub-classification (T3N0, T4aN0, and T4bN0). This study was aimed: (a) to investigate the impact of the AJCC 7th edition stage II sub-classification on the overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) of colon cancer patients who underwent surgical resection and (b) to compare the last three AJCC editions for identifying stage II patients with high-risk of progression.

METHODS

One hundred seventy-eight stage II colon cancers out of 682 colorectal cancer patients who underwent surgical resection were selected. T4N0 were sub-divided in accordance with the AJCC 7th edition. Mean follow-up was 41.9 months. Kaplan-Meier method was employed to estimate the survival curves.

RESULTS

OS analysis documented a significant difference between stage-sub-groups using the 6th edition; conversely, this difference was not seen if the 7th edition was applied (p = 0.03 and 0.12, respectively). Stage II DFS analysis reported a significant difference using both the AJCC 6th and 7th editions (p = 0.03 and 0.02, respectively). A significant difference was reported on stage II DSS analysis using the AJCC 6th edition (p = 0.03); however, when the 7th edition was applied, a substantial discrepancy between survival curves was noted with T3N0 and T4aN0 displaying similar outcomes (p = 0.006).

CONCLUSIONS

The AJCC 7th edition is a reliable classification that might implement the identification of those stage II colon cancer patients with high-risk of progression, recurrence, and cancer mortality.

Should quality measures for lymph node dissection in colon cancer be extrapolated to rectal cancer?

BACKGROUND

A minimum of 12 lymph nodes has been endorsed as a quality measure to confirm node-negative colon cancer, but its relevance to early-stage rectal cancer is unclear.

METHODS

Patients with stage I or II rectal cancer from the Surveillance, Epidemiology and End Results tumor registries from 1998 to 2002 were identified. Patients were grouped by the number of lymph nodes sampled. Groups were compared for patient demographics, tumor characteristics, and 5-year overall survival.

RESULTS

Of the 6,214 patients (57% men) identified, only 33% had ≥12 lymph nodes examined in the surgical specimen. Multivariate analysis identified sex, race, age, T stage, and number of lymph nodes examined as independent predictors of 5-year overall survival.

CONCLUSIONS

Five-year overall survival improved as the number of sampled nodes increased. A thorough lymphadenectomy should routinely be performed to optimize staging and to improve survival of patients with early-stage rectal cancer.

Toward the non-surgical management of locally advanced rectal cancer

Neoadjuvant short-course radiotherapy and long-course chemoradiation (CRT) reduce local recurrence rates when compared to surgery alone and remain widely accepted as standard of care for patients with locally advanced rectal cancer. However, surgery is not without complications and a non-surgical approach in carefully selected patients warrants evaluation. A pathological complete response to CRT is associated with a significant improvement in survival and it has been suggested that a longer time interval between the completion of CRT and surgery increases tumor downstaging. Intensification of neoadjuvant treatment regimens to increase tumor downstaging has been evaluated in a number of clinical trials and more recently the introduction of neoadjuvant chemotherapy prior to CRT has demonstrated high rates of radiological tumor regression. Careful selection of patients using high-resolution MRI may allow a non-surgical approach in a subgroup of patients achieving a complete response to neoadjuvant therapies after an adequate time period. Clearly this needs prospective evaluation within a clinical trial setting, incorporating modern imaging techniques, and tissue biomarkers to allow accurate prediction and assessment of response.

Validation of the seventh edition of the American Joint Committee on cancer tumor node-staging system in patients with colorectal carcinoma in comparison with sixth classification

BACKGROUND

The aim of this study was to compare survival rates assessed by the seventh-staging system with those by the sixth classification.

METHODS

This was a retrospective study of 3,377 patients who underwent surgery for colorectal adenocarcinoma from three university hospitals. The overall survival (OS) and cancer-specific survival (CSS) rates were compared between patients whose stages according to the seventh-staging system remained the same and patients whose stages migrated, and between subgroups within each new stage (homogeneity analysis).

RESULTS

In seventh edition, the 5-year OS and CSS rates of patients with T3n2 tumor were significantly greater in the downstaged patients (T3N2a) than in other patients (T3N2b) (OS, P = 0.010; CSS, P = 0.009). The 5-year survival rates for patients with T4a and T4b sub-classifications according to the seventh edition did not differ from those in patients with T4N0-1. Homogeneity analysis of subgroups classified using the new system showed that some subgroups of stage IIIB (T3N2a/T4aN1) had poorer survival rates compared with patients in other sub-categories in the same stage IIIB (P < 0.001).

CONCLUSION

Overall, the seventh edition provides a more detailed classification of the prognosis than the old system. However, further study would be warranted to evaluate the validity of sub-classification in seventh TNM-staging system, especially for T4a-b and T3N2a tumors.

Number of harvested lymph nodes is the main prognostic factor in Stage IIa colorectal cancer patients

BACKGROUND

Current international guidelines on colorectal cancer (CRC) treatment suggest performing adjuvant chemotherapy only in Stage II patients presenting with high-risk prognostic factors. Aim of the study was to a the impact of these parameters on the survival of Stage IIa CRC patients, focusing on the prognostic value of the number of harvested lymph nodes (NHLN).

PATIENTS AND METHODS

Out of 651 CRC patients undergoing surgical resection, 204 T3-N0-M0 were selected and reviewed. Univariate and multivariate survival analyses were adapted for the evaluation of the prognostic factors.

RESULTS

The 5 years actuarial DFS, DSS, and OS rates of patients with a NHLN >12 were significantly better compared to those of patients with a NHLN <12 (respectively: 72.8% vs. 50.4% P=0.001; 82% vs. 56% P=0.001; 78.5% vs. 53.1% P=0.001). Multivariate analysis revealed that a NHLN >12 was the only independent parameter of statistical significance influencing DFS, DSS, and OS.

CONCLUSIONS

According to our findings, the NHLN is the main predictor of survival in Stage IIa CRC patients. This would appear to suggest the need of a better stratification of Stage IIa CRC patients, sub-dividing patients with more or less than 12 NHLN.

Lymph node harvest in colon and rectal cancer: Current considerations

The prognostic significance of identifying lymph node (LN) metastases following surgical resection for colon and rectal cancer is well recognized and is reflected in accurate staging of the disease. An established body of evidence exists, demonstrating an association between a higher total LN count and improved survival, particularly for node negative colon cancer. In node positive disease, however, the lymph node ratios may represent a better prognostic indicator, although the impact of this on clinical treatment has yet to be universally established. By extension, strategies to increase surgical node harvest and/or laboratory methods to increase LN yield seem logical and might improve cancer staging. However, debate prevails as to whether or not these extrapolations are clinically relevant, particularly when very high LN counts are sought. Current guidelines recommend a minimum of 12 nodes harvested as the standard of care, yet the evidence for such is questionable as it is unclear whether an increasing the LN count results in improved survival. Findings from modern treatments, including down-staging in rectal cancer using pre-operative chemoradiotherapy, paradoxically suggest that lower LN count, or indeed complete absence of LNs, are associated with improved survival; implying that using a specific number of LNs harvested as a measure of surgical quality is not always appropriate. The pursuit of a sufficient LN harvest represents good clinical practice; however, recent evidence shows that the exhaustive searching for very high LN yields may be unnecessary and has little influence on modern approaches to treatment.

Prediction of prognosis is not improved by the seventh and latest edition of the TNM classification for colorectal cancer in a single-center collective

OBJECTIVES

To compare the prognostic value of the sixth and seventh editions of the TNM classification, and of additional prognostic factors, in colorectal cancer.

BACKGROUND

The seventh TNM edition was released in 2009 with the aim of providing a more precise prediction of prognosis.

METHODS

Clinical and histopathological data of 2229 patients with colorectal cancer who underwent tumor resection between 1990 and 2006 were analyzed and compared by using the sixth and seventh editions of the TNM classification and a statistically calculated model of prognostic factors.

RESULTS

With the sixth edition, 5-year survival was 96% for stage I, 90% for IIA, 86% for IIB, 90% for IIIA, 72% for IIIB, 48% for IIIC, and 13% for IV. With the seventh edition, 5-year survival was 96% for stage I, 90% for IIA, 84% for IIB, 87% for IIC, 89% for IIIA, 72% for IIIB, 36% for IIIC, 15% for IVA, and 10% for IVB. The stage shifted for only 155 (7%) patients: from IIB to IIC (2%), from IIIB to IIIC (1%), and from IIIC to IIIA/B (4%). The performance of the seventh edition [concordance index (c-index) 0.83; 95% confidence interval (CI), 0.82-0.85] revealed no relevant improvement compared with the sixth edition (c-index 0.83; 95% CI, 0.82-0.84), or compared to a model based on independent prognostic factors (c-index 0.84; 95% CI, 0.83-0.86).

CONCLUSIONS

The seventh TNM edition did not provide greater accuracy in predicting colorectal cancer patients' prognosis but resulted in a more complex classification for daily clinical use.

Post-therapy pathologic stage and survival in patients with pancreatic ductal adenocarcinoma treated with neoadjuvant chemoradiation

BACKGROUND

Neoadjuvant chemoradiation before surgery is an emerging treatment modality for pancreatic ductal adenocarcinoma (PDAC). However, analysis of prognostic factors is limited for patients with PDAC treated with neoadjuvant chemoradiation and pancreaticoduodenectomy (PD).

METHODS

The study population was comprised of 240 consecutive patients with PDAC who received neoadjuvant chemoradiation and PD and was compared with 60 patients who had no neoadjuvant therapy between 1999 and 2007. Clinicopathologic features were correlated with disease-free survival (DFS) and overall survival (OS).

RESULTS

Among the 240 treated patients, the 1-year and 3-year DFS rates were 52% and 32%, with a median DFS of 15.1 months. The 1-year and 3-year OS rates were 95% and 47%, with a median OS of 33.5 months. By univariate analysis, DFS was associated with age, post-therapy tumor stage (ypT), lymph node status (ypN), number of positive lymph nodes, and American Joint Committee on Cancer (AJCC) stage, whereas OS was associated with intraoperative blood loss, margin status, ypT, ypN, number of positive lymph nodes, and AJCC stage. By multivariate analysis, DFS was independently associated with age, number of positive lymph nodes, and AJCC stage, and OS was independently associated with differentiation, margin status, number of positive lymph nodes, and AJCC stage. In addition, the treated patients had better OS and lower frequency of lymph node metastasis than those who had no neoadjuvant therapy.

CONCLUSIONS

In patients with PDAC who received neoadjuvant chemoradiation and subsequent PD, post-therapy pathologic AJCC stage and number of positive lymph nodes are independent prognostic factors.

Salvage colectomy for endoscopically removed malignant colon polyps: is it possible to determine the optimal number of lymph nodes that need to be harvested?

AIM

The total number of lymph nodes examined after salvage colectomy for endoscopically removed malignant polyps was evaluated and an attempt was made to determine whether there was an optimal number of lymph nodes that should be harvested.

METHOD

From 2000 to 2009, 531 patients underwent segmental resection for non-metastatic colon cancer. Of these, 22 underwent a salvage colectomy for an endoscopically removed malignant polyp, the main indication for which was a resection margin of < 1 mm. The surgical procedure was identical to that used for all colon cancers.

RESULTS

The mean number of lymph nodes examined was 11.6 ± 7.6 for the 22 patients with an endoscopically removed malignant polyp and 26.2 ± 13.9 for the remaining 509 patients (P = 0.0006). Fewer than 12 lymph nodes were examined in 62 (12%) of the 509 patients and in 13 (59%) of the 22 patients with an endoscopically removed malignant polyp (P < 0.0001). In the group of 22 patients who underwent a salvage colectomy, the total number of lymph nodes examined ranged from 2 to 33. At a mean follow up of 41 ± 15.6 months, no local or distant recurrence was observed in the 22 patients.

CONCLUSION

The total number of lymph nodes examined after colectomy for endoscopically removed malignant polyps varies and is less than the recommended number of 12 in most cases: this does not appear to have long-term prognostic significance. There is no biological reason to explain this clinical observation.

Prognostic Significance of Lymph Node Ratio in Stage III Rectal Cancer

Purpose

Although nodal metastasis is the most powerful prognostic factor in rectal cancer, marked heterogeneity exists within stage III rectal cancer. Recent studies of rectal cancer have shown a prognostic superiority of the lymph node ratio (LNR) compared with N stage. The purpose of this study was to investigate the prognostic value of the LNR in the era of the 7th edition of the TNM classification.

Methods

We included 190 patients who underwent a curative resection for rectal cancer with nodal metastasis. The patients were divided into four groups on the basis of statistically calculated cut-off values as 0.21, 0.32, and 0.61.

Results

The LNR was an independent risk factor for overall survival (OS; P = 0.008) and for systemic recurrence-free survival (SRFS; P = 0.002). However, the LNR was not a predictive factor for local recurrence. When the N stage of the sixth TNM staging system was separately analyzed as a covariate, the LNR was also found to be a predictive factor for both OS and SRFS (P = 0.012 and P = 0.004, respectively). A LNR value of 0.21 offered the best cut off to separate patients into two prognostic groups.

Conclusion

The defined cut-off values of the LNR were an independent risk factor for OS and distant metastasis-free survival in patients with rectal cancer, irrespective of the sixth or the seventh version of the TNM classification, and the LNR should be considered as a prognostic variable in any future staging system.

Has the new TNM classification for colorectal cancer improved care?

In 2009, the Union for International Cancer Control issued the seventh edition of the well-used T (tumor), N (node), and M (metastasis) classification guidelines. There has been a continual refinement of the staging for colorectal cancer since this system for assessing tumor stage was initially adopted and it has been used to guide treatment decisions for over 50 years. However, the outcome after therapy for patients with colorectal cancer is very variable, even when patients are assigned to the same TNM category. This article assesses the changes that have been made since the sixth edition and discusses whether they are, in fact, informative improvements for a practicing clinician.

Neoadjuvant chemotherapy alone for early-stage rectal cancer: an evolving paradigm?

Current management of early-stage rectal cancer comprises combinations of surgery, radiotherapy, and chemotherapy, with the presence or absence of several validated high-risk features determining which treatment modalities will be used and the order of administration. In high-risk individuals, most centers have adopted neoadjuvant combined chemotherapy and radiotherapy followed by surgery as the initial approach. However, long-term toxicity, limited survival gains, and high rates of distant failure have called this approach into question, with early data suggesting that neoadjuvant chemotherapy alone may be feasible in selected patient groups. This review discusses the current data and feasibility of managing early stage rectal cancer with neoadjuvant chemotherapy before surgical resection.

Magnetic resonance imaging-detected tumor response for locally advanced rectal cancer predicts survival outcomes: MERCURY experience

PURPOSE

To assess magnetic resonance imaging (MRI) and pathologic staging after neoadjuvant therapy for rectal cancer in a prospectively enrolled, multicenter study.

METHODS

In a prospective cohort study, 111 patients who had rectal cancer treated by neoadjuvant therapy were assessed for response by MRI and pathology staging by T, N and circumferential resection margin (CRM) status. Tumor regression grade (TRG) was also assessed by MRI. Overall survival (OS) was estimated by using the Kaplan-Meier product-limit method, and Cox proportional hazards models were used to determine associations between staging of good and poor responders on MRI or pathology and survival outcomes after controlling for patient characteristics.

RESULTS

On multivariate analysis, the MRI-assessed TRG (mrTRG) hazard ratios (HRs) were independently significant for survival (HR, 4.40; 95% CI, 1.65 to 11.7) and disease-free survival (DFS; HR, 3.28; 95% CI, 1.22 to 8.80). Five-year survival for poor mrTRG was 27% versus 72% (P = .001), and DFS for poor mrTRG was 31% versus 64% (P = .007). Preoperative MRI-predicted CRM independently predicted local recurrence (LR; HR, 4.25; 95% CI, 1.45 to 12.51). Five-year survival for poor post-treatment pathologic T stage (ypT) was 39% versus 76% (P = .001); DFS for the same was 38% versus 84% (P = .001); and LR for the same was 27% versus 6% (P = .018). The 5-year survival for involved pCRM was 30% versus 59% (P = .001); DFS, 28 versus 62% (P = .02); and LR, 56% versus 10% (P = .001). Pathology node status did not predict outcomes.

CONCLUSION

MRI assessment of TRG and CRM are imaging markers that predict survival outcomes for good and poor responders and provide an opportunity for the multidisciplinary team to offer additional treatment options before planning definitive surgery. Postoperative histopathology assessment of ypT and CRM but not post-treatment N status were important postsurgical predictors of outcome.