Factors associated with local recurrence after neoadjuvant chemoradiation with total mesorectal excision for rectal cancer. World J Surg. 2009;33:1741-1749. [PMID: 19495867 DOI: 10.1007/s00268-009-0077-4]

Multicenter validation of the PREDICT score for prediction of local recurrence after total mesorectal excision of rectal cancer

BACKGROUND

Total mesorectal excision (TME) is the gold standard treatment for rectal cancer. Although TME has managed to decrease the rates of local recurrence after rectal cancer resection, local recurrence is still recorded at varying rates. The present study aimed to validate the PREDICT score in the prediction of local recurrence of rectal cancer after TME with curative intent.

METHODS

This was a retrospective multicenter study on patients with nonmetastatic low or middle rectal cancer who underwent TME. The total PREDICT score was calculated for every patient and related to the onset of local recurrence. According to the final score, patients were allocated to one of three risk groups: low, moderate, and high, and the rates of local recurrence in each group were calculated and compared.

RESULTS

The present study included 262 patients (50.4% males) with a mean age of 47.1 years. The overall local recurrence rate was 12.6%. 29.4% of patients were in the low-risk group, 63.7% in the moderate-risk group, and 6.9% in the high-risk group. The local recurrence rate was 3.9% (95% confidence interval [CI]: 0.8-10.9) in the low-risk group, 13.2% (95% CI: 8.4-19.3) in the moderate risk group, and 44.4% (95% CI: 21.5-69.2) in the high-risk group (p < 0.0001). The sensitivity of the PREDICT score was 72.7%, the specificity was 88.1%, and the accuracy was 86.3%.

CONCLUSIONS

The PREDICT score had good diagnostic accuracy in the prediction of local recurrence after TME and a good discriminatory ability in the differentiation between patients at different risks to develop local recurrence.

Development of the 'PREDICT' score through a systematic review and meta-analysis of the predictive parameters for locoregional recurrence after total mesorectal excision

BACKGROUND

Despite robust management techniques, locoregional recurrence rates of rectal cancer are still significant. Although offering intensive follow-up has been shown to be beneficial in the early detection, it can be resource consuming. Having a robust knowledge of risk factors of locoregional recurrence will help in identification of patients who actually need intensive follow-up programs. This review aimed to identify the factors that can predict locoregional recurrence after Total mesorectal excision (TME).

METHODS

We systematically reviewed PubMed, Scopus and Cochrane for relevant articles with no date restrictions while language was restricted to English. We only included articles that had either provided Hazards ratio (HR)/odds ratio (OR) or provided enough data that allowed calculation of HR/OR specifically for rectal cancer. Articles were deemed eligible if they included patients undergoing (TME).

RESULTS

Seventeen studies (18,605 patients) published between 2002 and 2019 were included. A total of 699 patients developed locoregional recurrence at a median time of 25.2 months after surgery. There were eight significant predictors evaluated by more than one study; T3-T4 stage, circumferential resection margin, lymphovascular invasion, mucinous histology, N1-N2 stage, positive distal resection margin, Tumor < 5 cm from anal verge, and lack of neoadjuvant radiotherapy. A scoring system was developed based on the weight and pooled OR/HR of each predictor.

CONCLUSION

Using predictive factors identified in our review in context of scoring system may help in the early detection of locoregional recurrence after TME. This may help in tailoring the application of intensive follow-up programs.

Early recurrence after neoadjuvant chemoradiation therapy for locally advanced rectal cancer: Characteristics and risk factors

BACKGROUND/OBJECTIVE

Some locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (CRT) prior to total mesorectal excision (TME) show early recurrence with a short disease-free interval. This is unacceptable for patients and their families, necessitating re-evaluation of the treatment process. We aimed to evaluate the risk factors and prognostic impact of early recurrence in patients who received preoperative CRT (pCRT) followed by TME for LARC.

METHODS

Of 714 patients who underwent curative resection after pCRT for LARC from January 2010 to December 2016, we included 139 who developed recurrence after resection. Patients were divided into an early recurrence group, diagnosed <12 months after primary surgery, and a late recurrence group, diagnosed ≥12 months after primary surgery.

RESULTS

Forty-nine patients experienced early recurrence and 90 experienced late recurrence. Multivariate analysis revealed that tumor regression grade (hazard ratio [HR] 2.962, 95% confidence interval [CI] 1.434-6.119, P = 0.003) and positive ypN stage (HR 2.110, 95% CI 1.144-3.892, P = 0.017) correlated with early recurrence. The 5-year overall survival rates for early and late recurrences were not significantly different (P = 0.121).

CONCLUSION

In patients with early recurrence after pCRT followed by TME, tumor regression grade and ypN stage positivity were independent predictors of the early recurrence.

Prognostic Implication of Negative Lymph Node Count in ypN+ Rectal Cancer after Neoadjuvant Chemoradiotherapy and Construction of a Prediction Nomogram

PURPOSE

This study aimed to investigate the prognostic significance of negative lymph nodes (NLNs) for ypN+ rectal cancer after neoadjuvant chemoradiotherapy (nCRT) and radical surgery and to construct a nomogram predicting disease-free survival (DFS).

METHOD

One hundred fifty-eight eligible patients were included. X-tile analysis was performed to determine cutoff values of NLNs. Clinicopathological and survival outcomes were compared. A Cox regression analysis was performed to identify prognostic factors of DFS. A nomogram was constructed and validated internally.

RESULTS

X-tile analysis identified cutoff values of 4 and 16 in terms of DFS (χ² = 8.129, p = 0.017). The 3-year DFS rates for low (≤ 4), middle (5-16), and high (≥ 17) NLNs group was 15.2, 55.5, and 73.1%, respectively (P = 0.017). NLN count (NLNs ≥ 17, HR = 0.400, P = 0.022), IMA nodal metastasis (HR = 1.944, P = 0.025), tumor differentiation (poor/anaplastic, HR = 1.805, P = 0.021), and ypT4 stage (HR = 7.787, P = 0.047) were independent prognostic factors of DFS. A predicting nomogram incorporating the four significant predictors was developed with a C-index of 0.64.

CONCLUSION

NLN count was an independent prognostic factor of DFS in patients with ypN+ rectal cancer following nCRT. A nomogram incorporating NLN count, IMA nodal metastasis, tumor differentiation, and ypT stage could stratify rectal cancer patients with different DFS and might be helpful during clinical decision-making.

Tumor compactness improves the preoperative volumetry-based prediction of the pathological complete response of rectal cancer after preoperative concurrent chemoradiotherapy

In addition to clinical factors (tumor and node stage) and treatment factors (equivalent radiotherapy dose and chemotherapy regimen), we assessed whether different performances of various tumor volume measurements help predict the pathological complete response (pCR) of locally advanced rectal cancer (LARC) after preoperative concurrent chemoradiotherapy (CCRT). A total of 122 patients with LARC treated with a long course of CCRT, between December 2009 and March 2015, were enrolled in this bi-institutional study. Tumor delineation was based on standard T2-weighted magnetic resonance imaging or contrast-enhanced computed tomography before CCRT. Tumor compactness was defined as the ratio of the volume and the surface area. The tumor compactness-corrected TV (TCTV) was defined as the ratio of the real TV (RTV) and tumor compactness. Twenty-three (18.9%) patients had a pCR. Areas under the curve of the receiver operating characteristic for pCR prediction calculated using the RTV, cylindrical approximated TV (CATV), and TCTV were 0.724, 0.747, and 0.780, respectively. The prediction performance of TCTV was significantly more efficient than that of both RTV (P = 0.0057) and CATV (P = 0.0329). Multivariate logistic regression analysis revealed tumor compactness (P = 0.001), RTV (P = 0.042), and preoperative clinical nodal status (P = 0.044) as significant predictors of a pCR. In addition, poor tumor compactness was closely associated with lymphovascular space invasion (P = 0.008) and pathological nodal status (P = 0.003). For patients with LARC receiving preoperative CCRT, tumor compactness is a useful radiomic parameter for improving the volumetric based prediction model.

Does circumferential tumor location affect the circumferential resection margin status in mid and low rectal cancer?

BACKGROUND/OBJECTIVE

The purpose of this study was to assess the impact of circumferential tumor location on circumferential resection margin (CRM) status and the depth of tumor invasion in mid and low rectal cancer.

METHODS

We retrospectively analyzed whole-mount slides of 58 patients who underwent total mesorectal excision for mid and low rectal cancer. The rate of tumor-positive CRM was compared according to the circumferential tumor location. In 31 patients, morphometric analyses of whole-mount specimens were performed to measure the depth of tumor invasion according to circumferential tumor location.

RESULTS

Among 58 patients, 50% of tumors were anterior tumor and 50% were nonanterior. A tumor-positive CRM was more observed frequently in anterior tumors than in nonanterior tumors (41.1% vs. 10.3%, p = 0.007). In a multivariate analysis, anterior tumor was the only independent risk factor for a positive CRM (odds ratio 4.725, 95% confidence interval 1.102-20.261, p = 0.037). In a morphometric analysis of 31 patients, the depth of tumor invasion from the muscularis mucosa was greater (11.9 mm vs. 6.6 mm, p = 0.028) in those with anterior tumors.

CONCLUSION

Anterior tumors are associated with a higher risk of tumor-positive CRM and tend to exhibit deeper invasion in mid and low rectal cancer.

A scoring system basing pathological parameters to predict regional lymph node metastasis after preoperative chemoradiotherapy for locally advanced rectal cancer: implication for local excision

Local excision is an alternative to radical surgery that is indicated in patients with locally advanced rectal cancer (LARC) who have a good response to chemoradiotherapy (CRT). Regional lymph node status is a major uncertainty during local excision of LARC following CRT. We retrospectively reviewed clinicopathologic variables for 244 patients with LARC who were treated at our institute between December 2000 and December 2013 in order to identify independent predictors of regional lymph node metastasis. Multivariate analysis of the training sample demonstrated that histopathologic type, tumor size, and the presence of lymphovascular invasion were significant predictors of regional nodal metastasis. These variables were then incorporated into a scoring system in which the total scores were calculated based on the points assigned for each parameter. The area under the curve in the receiver operating characteristic analysis was 0.750, and the cutoff value for the total score to predict regional nodal metastasis was 7.5. The sensitivity of our system was 73.2% and the specificity was 69.4%. The sensitivity was 77.8% and the specificity was 51.2% when the scoring system was applied to the testing sample. Using this system, we could accurately predict regional nodal metastases in LARC patients following CRT, which may be useful for stratifying patients in clinical trials and selecting potential candidates for organ-sparing surgery following CRT for LARC.

The number of retrieved lymph nodes needed for accurate staging differs based on the presence of preoperative chemoradiation for rectal cancer

The aim of this study is to investigate if retrieval of 12 lymph nodes (LNs) is sufficient to avoid stage migration as well as to evaluate the prognostic impact of insufficient LN retrieval in different treatment settings of rectal cancer, particularly in the case of preoperative chemoradiotherapy (pCRT).The data of all patients with biopsy proven rectal adenocarcinoma who underwent curative surgery between January 2005 and December 2012 were analyzed. Univariate and multivariate analyses for oncologic outcomes were performed in LN metastasis or no LN metastasis (LN-) group. Subgroup analyses were performed according to whether a patient had received pCRT.A total of 1825 patients were enrolled into the study. The maximal Chi-square method revealed the minimum number of harvested LNs required to be 12. Univariate and multivariate analyses found LNs ≥ 12 to be an independent prognostic factor for both overall survival (OS) (hazard ratio [HR] = 0.5, 95% confidence intervals [CIs]: 0.3-0.8; P = 0.002) and disease-free survival (DFS) (HR = 0.6, 95% CI: 0.4-0.7; P < 0.001) in the LN- group. In the LN- group, LNs ≥ 12 continued to be a significant prognostic factor both for OS and DFS in the subgroup of patients who did not undergo pCRT. However, in the subgroup of the LN- patients who underwent pCRT, LN ≥ 8 was significant for DFS and OS.Retrieval of LNs ≥ 12 and LNs ≥ 8 should be achieved to obtain accurate staging and optimal treatment for the non-pCRT and pCRT groups in rectal cancer, respectively.

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.

Multidisciplinary treatment of rectal cancer in 2014: Where are we going?

In the present review we discuss the recent developments and future directions in the multimodal treatment of locally advanced rectal cancer, with respect to staging and re-staging modalities, to the current role of neoadjuvant chemo-radiation and to the conservative and more limited surgical approaches based on tumour response after neoadjuvant combined therapy. When initial tumor staging is considered a high accuracy has been reported for T pre-treatment staging, while preoperative lymph node mapping is still suboptimal. With respect to tumour re-staging, all the current available modalities still present a limited accuracy, in particular in defining a complete response. The role of short vs long-course radiotherapy regimens as well as the optimal time of surgery are still unclear and under investigation by means of ongoing randomized trials. Observational management or local excision following tumour complete response are promising alternatives to total mesorectal excision, but need further evaluation, and their use outside of a clinical trial is not recommended. The preoperative selection of patients who will benefit from neoadjuvant radiotherapy or not, as well as the proper identification of a clinical complete tumour response after combined treatment modalities,will influence the future directions in the treatment of locally advanced rectal cancer.

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+.

Need for objective and reproducible criteria in histopathological assessment of total mesorectal excision specimens: lessons from a national improvement project

AIM

Data on quality control of the pathologic evaluation of total mesorectal excision (TME) specimens are scarce. We aimed to assess differences between evaluation by local pathologists participating in PROject on CAncer of the REctum (PROCARE; a Belgian improvement project on rectal cancer) and by a review panel of experts.

METHOD

Based on photographic material and histopathology slides, a Review Committee of gastrointestinal expert pathologists re-evaluated the mesorectal plane, the tumour differentiation grade, the (y)pT stage and the tumour regression grade in 444 patients previously routinely assessed by local pathologists.

RESULTS

The surgical plane was reported in 89% of patients and the circumferential resection margin in 88% of patients by the local pathologist. The median number of lymph nodes harvested in patients undergoing neoadjuvant radiochemotherapy was 11 and 14 in the other patients. The Review Committee downgraded the surgical plane from (intra)mesorectal to intramuscular in 17% of patients, and upgraded it from intramuscular to (intra)mesorectal in 27%. Tumour differentiation grade, T stage and tumour regression grade differed between local pathologists and the Review Committee in 15%, 10% and 38%, respectively, of patients. T stage was upgraded, mainly from T2 to T3, in 8% of patients. Tumour regression was judged by the Review Committee to be less advanced in 15% of patients.

CONCLUSION

Acknowledging some shortcomings, this study gives a realistic view of clinical practice. There are differences in interpretation with regard to both macroscopic and microscopic analysis of TME specimens. These findings indicate a need for more objective and reproducible criteria in histopathology. Being aware of this is a first step for improvement.

Prognostic significance of lymph node yield after long-course preoperative radiotherapy in patients with rectal cancer: a systematic review

AIM

A literature review was performed to elucidate whether long-course preoperative radiotherapy for patients with rectal cancer affects lymph node yield, and whether this influences prognosis.

METHOD

Cochrane Database, PubMed/MEDLINE, Scopus, Web of Knowledge, Embase and CINAHL databases and reference lists from published journal articles published between 1 January 1990 and 30 June 2011 were searched. Studies examining lymph node yield and prognosis were selected for review.

RESULTS

One thousand and twenty-nine articles were found, of which 11 met the inclusion criteria. None was a randomized controlled trial and all were cohort studies. Four studies showed that long-course preoperative radiotherapy reduced lymph node yield; however only one demonstrated a statistically significant survival benefit in patients with higher lymph node yields. Five-year survival was 48% in patients with fewer than and 69% in those with more than 11 lymph nodes identified in the operative specimen (P = 0.04).

CONCLUSION

Whilst long-course preoperative radiotherapy appears to reduce lymph node yield in patients with rectal cancer, no causal relationship between lymph node yield and survival can be established in this group of patients.

Evaluation of the impact of implementing the prone jackknife position for the perineal phase of abdominoperineal excision of the rectum

BACKGROUND

Abdominoperineal excision of rectum has been associated with poor oncological specimens and high local recurrence rates in comparison with restorative surgery. The role of recent changes in operative position has yet to be evaluated.

OBJECTIVES

This study aimed to determine whether a change in the perineal phase from the Lloyd-Davies position to the prone jackknife position might improve excision margins and oncological outcomes.

METHODS

A single-institution review of a prospectively maintained database comparing the quality of excision and oncological outcomes after abdominoperineal excision in conventional and prone position was performed. Consecutive abdominoperineal excisions performed for adenocarcinoma of the rectum between January 1999 and April 2008 were included.

RESULTS

Abdominoperineal excision cases were assessed including 63 in the Lloyd-Davies position and 58 in the prone jackknife position. The 5-year local recurrence rate was 5% in the prone jackknife group in comparison with 23% in the Lloyd-Davies group (p = 0.03) by life table analysis. For local recurrence, the most significant and independent risk factors were a favorable effect of having the patient in the prone jackknife position for the perineal phase of abdominoperineal excision (HR 0.2; 95% CI 0.04-0.81) and, unfavorably, a positive circumferential resection margin (HR 7.1; 95% CI 2.4-20). Lymph node involvement (N2) was an independent risk factor for overall survival (HR 4.6; 95% CI 2.1-9.5) and relapse of disease (HR 4.0; 95% CI 0.7-9.4).

LIMITATIONS

This study has some limitations because it is a retrospective review of a prospective database.

CONCLUSION

These data suggest that the rate of local recurrence after abdominoperineal excision may be lowered by adaptation of the prone jackknife position.

Number of lymph nodes after neoadjuvant therapy for rectal cancer: How many are needed?

Dear readers,

In the February 2012 issue of the World J Gastrointest Surg (4(2):32-35) Scabini and Ferrando published an editorial entitled “Number of lymph nodes after neoadjuvant therapy for rectal cancer: how many are needed?”.It has been brought to our attention that segments of the editorial are identical or closely resemble the essential parts of the discussion of the original article “Preoperative chemoradiotherapy does not necessarily reduce lymph node retrieval in rectal cancer specimens ¨C Results from a prospective evaluation with extensive pathological work-up” that was published in the Journal of Gastrointestinal Surgery in 2009. Given the striking similarities of the two works, the World J Gastrointest Surg has decided to retract the editorial by Scabini and Ferrando.

Timothy M. Pawlik, MD, MPH, PhD

Editor-in-Chief, World Journal of Gastrointestinal Surgery

The surgical significance of residual mucosal abnormalities in rectal cancer following neoadjuvant chemoradiotherapy

BACKGROUND

Local excision of rectal cancer after neoadjuvant chemoradiotherapy (CRT) has been proposed as an alternative to radical surgery in selected patients. However, little is known about the significance of the morphological and histological features of residual tumour.

METHODS

Patients who had undergone CRT at the authors' institution between 1997 and 2010 were identified. Multiple features were assessed as putative markers of pathological response. These included: gross residual disease, diameter of residual mucosal abnormalities, tumour differentiation, presence of lymphovascular/perineural invasion and lymph node ratio.

RESULTS

Data from 220 of 276 patients were suitable for analysis. Diameter of residual mucosal abnormalities correlated strongly with pathological tumour category after CRT (ypT) (P < 0·001). Forty of 42 tumours downstaged to ypT0/1 had residual mucosal abnormalities of 2·99 cm or less after CRT. Importantly, 19 of 31 patients with a complete pathological response had evidence of a residual mucosal abnormality consistent with an incomplete clinical response. The ypT category was associated with both pathological node status after CRT (P < 0·001) and lymph node ratio (P < 0·001). Positive nodes were found in only one of 42 patients downstaged to ypT0/1. The risk of nodal metastases was associated with poor differentiation (P = 0·027) and lymphovascular invasion (P < 0·001).

CONCLUSION

In this series, the majority of patients with a complete pathological response did not have a complete clinical response. In tumours downstaged to ypT0/1 after CRT, residual mucosal abnormalities were predominantly small and had a 2 per cent risk of positive nodes, thus potentially facilitating transanal excision. The presence of adverse histological characteristics risk stratified tumours for nodal metastases.

Oncologic outcomes of primary and post-irradiated early stage rectal cancer: A retrospective cohort study

AIM: To evaluate the oncologic outcomes of primary and post-irradiated early stage rectal cancer and the effectiveness of adjuvant chemotherapy for rectal cancer patients.

METHODS: Eighty-four patients with stage I rectal cancer after radical surgery were studied retrospectively and divided into ypstage I group (n = 45) and pstage I group (n = 39), according to their preoperative radiation, and compared by univariate and multivariate analysis.

RESULTS: The median follow-up time of patients was 70 mo. No significant difference was observed in disease progression between the two groups. The 5-year disease-free survival rate was 84.4% and 92.3%, respectively (P = 0.327) and the 5-year overall survival rate was 88.9% and 92.3%, respectively, for the two groups (P = 0.692). The disease progression was not significantly associated with the pretreatment clinical stage in ypstage I group. The 5-year disease progression rate was 10.5% and 19.2%, respectively, for the patients who received adjuvant chemotherapy and for those who rejected chemotherapy in the ypstage I group (P = 0.681).

CONCLUSION: The oncologic outcomes of primary and post-irradiated early stage rectal cancer are similar. Patients with ypstage I rectal cancer may slightly benefit from adjuvant chemotherapy.

Clinical significance of pre- to post-chemoradiotherapy s-CEA reduction ratio in rectal cancer patients treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the clinical significance of a reduction in serum carcinoembryonic antigen (s-CEA) concentration ratio from before to after preoperative chemoradiotherapy (CRT) in terms of recurrence and prognostic factors in rectal cancer patients.

METHODS

We retrospectively evaluated 333 rectal cancer patients who received preoperative CRT followed by surgery with curative intent between January 2000 and December 2006. Patients were divided into three groups: those with pre-CRT s-CEA≤6 ng/mL (group 1), those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA≥70% lower than pre-CRT s-CEA (group 2), and those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA<70% lower or higher than pre-CRT s-CEA (group 3).

RESULTS

The 5-year disease-free survival rate was similar in group 1 (76.0%) and group 2 (66.0%), but significantly lower in group 3 (39.5%) (p<0.001). Multivariate analysis showed that CEA group 3, ypT stage, ypN stage, and type of surgery were independent prognostic factors for disease-free survival.

CONCLUSIONS

The reduction ratio of pre- to post-CRT s-CEA concentration may be an independent prognostic factor for disease-free survival following preoperative CRT and surgery in rectal cancer patients with initial s-CEA>6 ng/mL.

The prognostic value of lymph node ratio after neoadjuvant chemoradiation and rectal cancer surgery

BACKGROUND

Neoadjuvant chemotherapy decreases total lymph nodes harvested and possibly affects lymph node staging after total mesorectal excision in patients with rectal cancer.

OBJECTIVE

This study aimed to compare staging by lymph node ratio with staging by absolute number of positive lymph nodes.

DESIGN

This study is a retrospective cohort review.

SETTING

: A tertiary care referral center was the setting for this investigation.

PATIENTS

A total of 281 consecutive patients who underwent neoadjuvant chemoradiation and total mesorectal excision after histologically confirmed rectal cancer between January 1, 1998 and December 31, 2008 were included in this study.

MAIN OUTCOME MEASURES

Lymph node ratio is the number of positive lymph nodes divided by the total number of lymph nodes within one sample. Risk categories of low (0 to < 0.09); medium (0.09 to < 0.36); and high (≥ 0.36) for lymph node ratio were chosen by significance with the use of Cox proportional hazards models. These categories were then used in a reclassification table and compared with positive lymph node stage: low (0 positive nodes), medium (1-3 nodes), and high (> 3) by 5-year mortality rates.

RESULTS

The majority (87%) of patients were concordant in risk assessment. Thirty patients were downstaged to lower risk lymph node ratio categories without showing actual lower mortality rates. Seven patients were upstaged to a high-risk lymph node ratio category with a supporting higher 5-year mortality rate. When limiting the analysis to those with fewer than 12 nodes, 136 (95%) patients were concordant in risk assessment; all 30 incorrectly downstaged patients were removed, but the 7 correctly upstaged patients remained.

CONCLUSIONS

Patients who undergo neoadjuvant chemoradiation before rectal cancer surgery frequently have fewer than 12 lymph nodes harvested despite maintaining vigorous surgical standards. Lymph node ratios may provide excellent prognostic value and are possibly a better independent staging method than absolute positive lymph node counts when less than 12 lymph nodes are harvested after neoadjuvant treatment.

Magnetic resonance imaging-detected lymph nodes close to the mesorectal fascia are rarely a cause of margin involvement after total mesorectal excision

BACKGROUND

In rectal cancer the management of suspicious magnetic resonance imaging (MRI)-detected lymph nodes lying close to the mesorectal fascia poses an ongoing dilemma. Key decisions in treatment planning are commonly based on the prediction of margin status. However, it is unclear whether a lymph node that appears to contain tumour close to the mesorectal fascia will result in a positive margin.

METHODS

Some 396 patients with rectal cancer were included. MRI assessment of mesorectal nodes, the pathologically involved circumferential resection margin (CRM) rate and causes of margin involvement were analysed to establish the clinical significance of MRI-detected suspicious lymph nodes at the resection margin.

RESULTS

Fifty (12.6 per cent) of 396 patients had a positive CRM on histopathological analysis, five (10 per cent) solely due to an involved lymph node. Four of the five malignant nodes were not predicted on MRI. Thirty-one of the 396 MRI studies had suspicious nodes 1 mm or less from the CRM. None of these patients had a positive CRM owing to nodal involvement.

CONCLUSION

Involvement of the CRM by lymph node metastases alone is uncommon.