New Tumor-Node-Metastasis Staging Strategy for Node-Positive (stage III) Rectal Cancer: An Analysis

Primary staging of rectal cancer on MRI: an updated pictorial review with focus on common pitfalls and current controversies

Magnetic resonance imaging (MRI) plays a pivotal role in primary staging of rectal cancer, enabling the determination of appropriate management strategies and prediction of patient outcomes. However, inconsistencies and pitfalls exist in various aspects, including rectal anatomy, MRI protocols and strategies for artifact resolution, as well as in T- and N-staging, all of which limit the diagnostic value of MRI. This narrative and pictorial review offers a comprehensive overview of factors influencing primary staging of rectal cancer and the role of MRI in assessing them. It highlights the significance of the circumferential resection margin and its relationship with the mesorectal fascia, as well as the prognostic role of extramural venous invasion and tumor deposits. Special attention is given to tumors of the lower rectum due to their complex anatomy and the challenges they pose in MRI staging. The review also addresses current controversies in rectal cancer staging and the need for personalized risk stratification. In summary, this review provides valuable insights into the role of MRI in the primary staging of rectal cancer, emphasizing key aspects for accurate assessment to enhance patient outcomes.

Structured and shared MRI staging lexicon and report of rectal cancer: A consensus proposal by the French Radiology Group (GRERCAR) and Surgical Group (GRECCAR) for rectal cancer

PURPOSE

To develop French guidelines by experts to standardize data acquisition, image interpretation, and reporting in rectal cancer staging with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Evidence-based data and opinions of experts of GRERCAR (Groupe de REcherche en Radiologie sur le CAncer du Rectum [i.e., Rectal Cancer Imaging Research Group]) and GRECCAR (Groupe de REcherche en Chirurgie sur le CAncer du Rectum [i.e., Rectal Cancer Surgery Research Group]) were combined using the RAND-UCLA Appropriateness Method to attain consensus guidelines. Experts scoring of reporting template and protocol for data acquisition were collected; responses were analyzed and classified as "Recommended" versus "Not recommended" (when ≥ 80% consensus among experts) or uncertain (when < 80% consensus among experts).

RESULTS

Consensus regarding patient preparation, MRI sequences, staging and reporting was attained using the RAND-UCLA Appropriateness Method. A consensus was reached for each reporting template item among the experts. Tailored MRI protocol and standardized report were proposed.

CONCLUSION

These consensus recommendations should be used as a guide for rectal cancer staging with MRI.

Significance of Lymph Node Resection After Neoadjuvant Therapy in Pancreatic, Gastric, and Rectal Cancers

OBJECTIVE

Gastrointestinal cancers are increasingly being treated with NAT before surgical resection. Currently, quality metrics are linked to the number of LNs resected to determine subsequent treatment and prognosis. We hypothesize that NAT decreases LN metastasis, downstages patients, and decreases overall lymph node yields (LNY) compared to initial surgical resection. With increasing use of NAT, this brings into question the validity of quality metrics.

METHODS

Gastric (stage II/III), pancreatic (stage I/II/III), and rectal cancers (stage II/III) (2010-2015) treated with surgery with/without NAT were identified in National Cancer Database. We evaluated total LNY and LN metastasis with/without NAT and clinical and pathological stage to evaluate rates of downstaging.

RESULTS

A total of 7934 gastric, 15,908 pancreatic, and 21,354 rectal cancer patients were included of which 61.1%, 21.2%, and 85.7% received NAT, respectively. NAT patients were more likely to be downstaged (39.9% vs 11.1% gastric P< 0.001, 30.6% vs 3.2% pancreatic P< 0.001, 52.0% vs 16.3% rectal P< 0.001), have lower LNYs (18.8 vs 19.1 gastric P = 0.239, 18.4 vs 17.5 pancreatic P< 0.001, 15.7 vs 20.0 rectal P< 0.001) and have N0 pathologic disease (43.6% vs 26.7% gastric P< 0.001, 51.1% vs 30.9% pancreatic P< 0.001, 65.9% vs 49.4% rectal P< 0.001) when compared to initial surgical resection.

CONCLUSION

NAT for gastrointestinal cancers results in overall lower LN yields, lower LN metastases, and significant downstaging of tumors. As all patients undergoing NAT receive multimodality therapy, LN yield recommendations may not be true quality metric changing.

Retrospective survival analysis of stage II-III rectal cancer: tumour regression grade, grading and lymphovascular invasion are the only predictors

BACKGROUND

Tumour regression grade is gaining interest as a prognostic factor of patients undergoing neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer.

METHODS

A series of 68 consecutive patients with locally advanced rectal cancer treated by neoadjuvant chemoradiotherapy and surgery between 2010 and 2016 was retrospectively studied. The impact on disease-free survival (DFS) and overall survival (OS) of several criteria was analysed. Univariate analysis was performed through Kaplan-Meier statistics. Multivariate analysis was performed through Cox regression model. Using criteria found to be related to long-term outcomes, a predictive model of patient's OS was calculated.

RESULTS

Poor tumour regression grade - TRG3 (P = 0.010), poor grading - G3 (P = 0.001) and lymphovascular invasion (LVI; P = 0.030) were associated with short OS at univariate analysis. OS was associated with TRG3 and G3 at multivariate analysis (P = 0.016 and P = 0.027, respectively). DFS was associated with LVI (P = 0.001), G3 tumours (P = 0.046) and TRG3 (P = 0.045) at univariate analysis. At multivariate analysis, only LVI was associated with DFS (P = 0.041). A score, pondering the impact of three parameters (2 points for TRG3, 2 for G3 and 1 for LVI), was created and resulted to predict patient OS (P = 0.008), ranging from 94.5 months (score = 0-1) to 32 months (score = 3-5).

CONCLUSION

TRG3 and G3 were associated with poor OS, and LVI was the most significant predictor of DFS. An easy-to-use score may allow for a more accurate prediction of OS.

Rectal cancer MR staging: pearls and pitfalls at baseline examination

In recent years, rectal MRI has become a central diagnostic tool in rectal cancer staging. Indeed, rectal MR has the ability to accurately evaluate a number of important findings that may impact patient management, including distance of the tumor to the mesorectal fascia, presence of extramural vascular invasion (EMVI), presence of lymph nodes, and involvement of the peritoneum/anterior peritoneal reflection. Many of these findings are difficult to assess in nonexpert hands. In this review, we present a practical approach for radiologists to provide high-quality interpretations at initial baseline exams, based on recent guidelines from the Society of Abdominal Radiology, Rectal and Anal Cancer Disease Focused Panel. Practical pearls and pitfalls are discussed, focusing on optimization of technique including, patient preparation and protocol recommendations, interpretation, and essentials of reporting.

Poorer Oncologic Outcome of Good Responders to PCRT With Remnant Lymph Nodes Defies the Oncologic Paradox in Patients With Rectal Cancer

INTRODUCTION

We evaluated the oncologic outcome of (y)pT0-2N+ rectal cancer and investigated the impact of metastatic lymph nodes (LNs) on oncologic outcome in the setting of preoperative chemoradiotherapy (PCRT).

MATERIALS AND METHODS

The records of 1403 patients who underwent surgery for rectal cancer between January 2005 and December 2012 were analyzed. The patients were categorized according to the pathologic stage, including 728 patients with ypT0-2 and 675 with ypT3-4 disease. The oncologic outcomes in terms of the 5-year recurrence-free survival (RFS) and overall survival (OS) were analyzed.

RESULTS

Metastatic LNs were observed in 11.5% (n = 84) of patients with ypT0-2 and 42.9% (n = 290) of patients with ypT3-4 disease. The RFS and OS were stratified according to ypT and ypN stage as ypT0-2N0, T0-2N+, T3-4N0, and T3-4N+. The ypT0-2N+ group had slightly lower RFS and OS than those in the ypT3-4N0 group. LN metastasis was significantly associated with RFS in both ypT0-2 and ypT3-4 disease, with a stronger association for ypT0-2 disease (hazard ratio, 3.473, 95% confidence interval, 2.058-5.261; P < .001 for ypT0-2 and hazard ratio, 2.038; 95% confidence interval, 1.601-2.684; P < .001 for ypT3-4, respectively).

CONCLUSION

The oncologic outcomes of ypT0-2N+ disease were not favorable compared with those of ypT3-4N0 disease. These outcomes dispute the survival paradox traditionally believed for non-PCRT-treated patients with rectal cancer, and highlight the underestimated significance of post-PCRT nodal involvement. The prognostic importance of metastatic LNs should be considered when deciding the surgical strategy after PCRT. Further studies including larger numbers of patients with sufficient follow-up are needed to verify the oncologic impact of metastatic LNs within tumors contained within the bowel wall after PCRT.

The survival and clinicopathological differences between patients with stage IIIA and stage II rectal cancer: An analysis of 12,036 patients in the SEER database

BACKGROUND

Stage IIIA rectal cancer has distinctive oncological features, including limited depth of intestinal wall invasion and early regional lymph node metastasis. We aim to compare survival outcomes and clinicopathological features for stage IIIA rectal cancer with those for stage II rectal cancer.

METHODS

We analyzed patients with stage II or stage IIIA rectal cancer treated with surgery without receiving preoperative radiotherapy based on data from the US Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2003. Survival curves were plotted using the Kaplan-Meier method. Multivariate Cox proportional analyses were utilized to analyze independent prognostic factors for cancer-specific survival (CSS).

RESULTS

We included 12,036 rectal cancer patients (10,132 stage II and 1,904 stage IIIA) from the SEER database. Patients with stage IIIA rectal cancer had smaller tumor size than patients with stage II rectal cancer. A multivariate analysis suggested that compared with patients with stage IIIA rectal cancer, patients with stage II disease were more likely to have more unfavorable CSS (HR 1.195, 95% CI 1.079-1.324, p=0.001). When stage II rectal cancer was further analyzed as stage IIA, IIB and IIC rectal cancer, the multivariate analysis indicated that compared with patients with stage IIIA rectal cancer, patients with stage IIA rectal cancer (HR 1.113, 95% CI 1.003-1.235, p=0.044), stage IIB rectal cancer (HR 1.493, 95% CI 1.267-1.758, p<0.001) and stage IIC rectal cancer (HR 2.712, 95% CI 2.319-3.171, p<0.001) were also more likely to exhibit more unfavorable CSS.

CONCLUSIONS

Patients with stage IIIA rectal cancer had more favorable survival outcomes and smaller tumor size compared with patients with stage II rectal cancer.

Preoperative chemoradiotherapy for clinically diagnosed T3N0 rectal cancer

PURPOSE

This retrospective study compared the recurrence-free survival (RFS) and local recurrence rates of patients who received preoperative chemoradiotherapy (PCRT) for cT3N0 vs. those who did not.

METHODS

We analyzed the records of 593 patients with transrectal ultrasound (TUS) or magnetic resonance image (MRI)-staged cT3N0 mid and low locally advanced rectal cancer, including 255 who received PCRT and 338 who did not. The RFS and cumulative local recurrence rates were compared in the two groups. We also investigated the rates of pathologic complete response (pCR) and mesorectal lymph node (LN) involvement in the PCRT group.

RESULTS

The overall pCR rate was 13.3 %. Of the 338 non-PCRT patients, 125 (37.0 %) had pathologically positive mesorectal LNs. Sphincter-preserving surgery was performed in 431 (72.7 %) of the 593 patients, with similar rates in the two groups. However, the sphincter preservation rate in patients with low rectal cancer was higher among those who received PCRT than among those who did not (64.8 vs. 47 %, P = 0.002). The 5-year RFS (76.4 vs. 75.5 %, P = 0.92) and local recurrence (3.9 vs. 3.0 %, P = 0.97) rates were similar in the PCRT and non-PCRT groups.

CONCLUSION

Although PCRT did not improve the RFS or local recurrence rates, it increased the chance of sphincter preservation in patients with low rectal cancer. The advantages of PCRT for patients with cT3N0 should be re-evaluated considering the limitation of pretreatment staging, oncologic benefits, and improved sphincter preservation.

Lymph node ratio predicts tumor recurrence in stage III colon cancer

OBJECTIVE

To evaluate the lymph node ratio as a predictor for tumor recurrence in stage III colon cancer patients.

METHODS

Patients with stage III colon cancer who underwent curative resection between January 2005 and December 2010 were retrospectively reviewed. The main outcomes were tumor recurrence and death. The impact of lymph node ratio and other clinicopathological factors on disease-free survival were evaluated by uni- and multivariate analysis. Receiver operator characteristic (ROC) analysis was conducted in order to identify the best cutoff value for lymph node ratio to predict tumor recurrence. Disease-free survival was estimated by the Kaplan-Meier method.

RESULTS

Seventy patients were included in the study (50% male). The mean age was 64 years. Univariate analysis identified four factors for tumor recurrence: carcinoembryonic antigen, N stage, number of positive lymph nodes and lymph node ratio. Lymph node ratio was the one with the greatest magnitude of association. Receiver operator characteristic analyzes identified 0.15 as the best cutoff value. Patients with a lymph node ratio < 0.15 had a disease-free survival of 90% in 3 years (versus 64%, p = 0.011).

CONCLUSION

Lymph node ratio is a strong predictor for tumor recurrence in stage III colon cancer.

Cancer staging in outcomes assessment

The T N M staging system created by a surgeon in the 1950s continues to be a major benchmark for assessing long-term outcomes in adult solid tumors. Although several major changes have occurred in this anatomical staging system, the tenets of TNM staging remain constant. Recently molecular markers and biologic modifiers have been added to this anatomical staging system to create a more robust outcomes tool.

Surveillance, epidemiology, and end results-based analysis of the impact of preoperative or postoperative radiotherapy on survival outcomes for T3N0 rectal cancer

PURPOSE

Preoperative chemoradiation has been established as standard of care for T3/T4 node-positive rectal cancer. Recent work, however, has called into question the overall benefit of radiation for tumors with lower risk characteristics, particularly T3N0 rectal cancers. We retrospectively analyzed T3N0 rectal cancer patients and examined how outcomes differed according to the sequence of treatment received.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to analyze T3N0 rectal cancer cases diagnosed between 1998 and 2008. Treatment consisted of surgery alone (No RT), preoperative radiation followed by surgery (Neo-Adjuvant RT), or surgery followed by postoperative radiation (Adjuvant RT). Demographic and tumor characteristics of the three groups were compared using t-tests for the comparison of means. Survival information from the SEER database was utilized to estimate cause-specific survival (CSS) and to generate Kaplan-Meier survival curves. Multivariate analysis (MVA) of features associated with outcomes was conducted using Cox proportional hazards regression models with Adjuvant RT, Neo-Adjuvant RT, No RT, histological grade, tumor size, year of diagnosis, and demographic characteristics as covariates.

RESULTS

10-Year CSS estimates were 66.1% (95% CI 62.3-69.6%; P=0.02), 73.5% (95% CI 68.9-77.5%; P=0.02), and 76.1% (95% CI 72.4-79.4%; P=0.02), for No RT, Neo-Adjuvant RT, and Adjuvant RT, respectively. On MVA, Adjuvant RT (HR=0.688; 95% CI, 0.578-0.819; P<0.001) was associated with significantly decreased risk for cancer death. By contrast, Neo-Adjuvant RT was not significantly associated with improved cancer survival (HR=0.863; 95% CI, 0.715-1.043; P=0.127).

CONCLUSION

Adjuvant RT was associated with significantly higher CSS when compared with surgery alone, while the benefit of Neo-Adjuvant RT was not significant. This indicates that surgery followed by Adjuvant RT may still be an important treatment plan for T3N0 rectal cancer with potentially significant survival advantages over other treatment sequences.

Improvements in 5-year outcomes of stage II/III rectal cancer relative to colon cancer

BACKGROUND

Stage for stage, rectal cancer has historically been associated with inferior survival compared with colon cancer. Randomized trials of rectal cancer have generally demonstrated improvements in locoregional relapse but not survival.

OBJECTIVE

We compared therapy and outcomes of colon versus rectal cancer in 2 time cohorts to determine if relative improvements have occurred.

PATIENTS AND METHODS

Patients with resected stage II/III colorectal cancer referred to the British Columbia Cancer Agency in 1989/1990 and 2001/2002 were identified. The higher of clinical or pathologic stage was used for patients receiving preoperative chemoradiation. Disease-specific survival (DSS) and overall survival (OS) were compared for rectal and colon cancer between the 2 cohorts. Kaplan-Meier method was used for survival analysis.

RESULTS

A total of 1427 patients were included, with 375 from 1989/1990 and 1052 from 2001/2002. Between 1989/1990 and 2001/2002 there were significant increases in the use of perioperative chemotherapy for both rectal and colon cancer (P<0.001) and use of preoperative radiation therapy (P<0.001) and total mesorectal excision (P<0.001) in rectal cancer. DSS significantly improved for rectal (P<0.001) but not colon cancer (P=0.069). Five-year OS was significantly inferior for rectal versus colon cancer in 1989/1990 (46.1% vs. 57.2%, P=0.023) and was similar to that of colon cancer in 2001/2002 (63.7% vs. 66.2%, P=0.454).

CONCLUSIONS

Advances in locoregional and systemic therapy significantly improved survival among patients with rectal cancer. DSS and OS are now similar between colon and rectal cancer for both stage II and III disease.

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.

Factors predicting worse prognosis in patients affected by pT3 N0 colon cancer: long-term results of a monocentric series of 137 radically resected patients in a 5-year period

BACKGROUND AND PURPOSE

For patients with Stage II colon cancer, the use of adjuvant chemotherapy remains controversial. The purpose of this study was to identify clinical and/or pathological findings related to a worse prognosis in this category of patients.

PATIENTS AND METHODS

We retrospectively analyzed the data of consecutive patients, extracted by an institutional Tumour Registry, admitted to an affiliated University Hospital in Milan (European Institute of Oncology) for adenocarcinoma of the colon (all sites), between 2000 and 2005, and having a final pT3 N0 pathology staging after curative surgery. Adjuvant chemotherapy was decided as a result of a medical decision within a multidisciplinary Tumor Board.

RESULTS

Data of 137 patients were obtained, with a median follow-up of 77 months (range 6-131). Patients who received chemotherapy were younger than patients who did not. Nine patients out of 137 (6.5 %) died as a consequence of colon cancer recurrence; four of them had received adjuvant chemotherapy. Only histological grade III and mucinous histotype were found to impact on cumulative incidence of colon-related events (p 0.03 and 0.02, respectively); no impact was found on cumulative incidence of colonic neoplasm recurrence-related deaths (p 0.74 and 0.74, respectively). Number of analyzed LNs (lymph nodes) emerged as a factor possibly affecting the cumulative incidence of colon-related events (p 0.09) as well as the cumulative incidence of colonic neoplasm recurrence-related deaths (p 0.10). The risk of events was inversely proportional to the number of dissected LNs, even over 20 up to about 25 LNs. Never-smokers exhibited a lower incidence of colon-related events, although the difference was not statistically significant (p 0.09). All other analyzed variables did not show any impact on survival rate, including age, gender, ASA score, BMI, site of colonic neoplasm, multifocality, perivascular invasion, and use of adjuvant chemotherapy.

CONCLUSIONS

Histology grading G3 and mucinous histotype were predictors of worse outcome. Efforts to improve LN evaluation should result in clinically significant improvements in outcome, and also the quality of care for patients with radically resected stage II colon cancer.

MicroRNA expression profile associated with response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer patients

Background

Rectal cancer accounts for approximately one third of all colorectal cancers (CRC), which belong among leading causes of cancer deaths worldwide. Standard treatment for locally advanced rectal cancer (cT3/4 and/or cN+) includes neoadjuvant chemoradiotherapy with fluoropyrimidines (capecitabine or 5-fluorouracil) followed by radical surgical resection. Unfortunately, a significant proportion of tumors do not respond enough to the neoadjuvant treatment and these patients are at risk of relapse. MicroRNAs (miRNAs) are small non-coding RNAs playing significant roles in the pathogenesis of many cancers including rectal cancer. MiRNAs could present the new predictive biomarkers for rectal cancer patients.

Methods

We selected 20 patients who underwent neoadjuvant chemoradiotherapy for advanced rectal cancer and whose tumors were classified as most sensitive or resistant to the treatment. These two groups were compared using large-scale miRNA expression profiling.

Results

Expression levels of 8 miRNAs significantly differed between two groups. MiR-215, miR-190b and miR-29b-2* have been overexpressed in non-responders, and let-7e, miR-196b, miR-450a, miR-450b-5p and miR-99a* have shown higher expression levels in responders. Using these miRNAs 9 of 10 responders and 9 of 10 non-responders (p < 0.05) have been correctly classified.

Conclusions

Our pilot study suggests that miRNAs are part of the mechanisms that are involved in response of rectal cancer to the chemoradiotherapy and that miRNAs may be promising predictive biomarkers for such patients. In most miRNAs we identified (miR-215, miR-99a*, miR-196b, miR-450b-5p and let-7e), the connection between their expression and radioresistance or chemoresistance to inhibitors of thymidylate synthetase was already established.

Multimodal treatment strategies for locally advanced rectal cancer

This review outlines the important multimodal treatment issues associated with locally advanced rectal cancer. Changes to chemotherapy and radiation schema, as well as modern surgical approaches, have led to a revolution in the management of this disease but the morbidity and mortality remains high. Adequate treatment is dependent on precise preoperative staging modalities. Advances in staging via endorectal ultrasound, computed tomography, MRI and PET have improved pretreatment triage and management. Important prognostic factors and their impact for this disease are under investigation. Here we discuss the different treatment options including modern tumor-related surgical approaches, neoadjuvant as well as adjuvant therapies. Further clinical progress will largely depend on the broader implementation of multidisciplinary treatment strategies following the principles of evidence-based medicine.

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.

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.

Unique considerations in the patient with rectal cancer

In the past two decades, substantial progress has been made in the adjuvant management of colorectal cancer. Chemotherapy has improved overall survival in patients with node-positive (N+) disease. In contrast with colon cancer, which has a low incidence of local recurrence, patients with rectal cancer have a higher incidence requiring the addition of pelvic radiation therapy (chemoradiation). Patients with rectal cancer have a number of unique management considerations: for example, the role of short-course radiation, whether postoperative adjuvant chemotherapy is necessary for all patients, and if the type of surgery following chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation as well as modify the need for pelvic radiation? This review will address these and other controversies specific to patients with rectal cancer.

Effects of postoperative adjuvant radiotherapy on recurrence and survival in stage III rectal cancer

BACKGROUND

The aim of this study is to evaluate whether the addition of radiotherapy to chemotherapy would enhance the benefits obtained with chemotherapy alone, in stage III rectal cancer in the era of preoperative chemoradiotherapy and total mesorectal excision (TME).

METHODS

From January 1999 to January 2008, 300 stage III rectal cancer patients who underwent TME were prospectively identified; a total of 46 patients who received preoperative chemoradiotherapy or did not receive adjuvant therapy were excluded. Patients who received postoperative chemotherapy alone (n=190) and those who received postoperative chemoradiotherapy (n=64) were compared.

RESULTS

The median follow-up period was 52 (range, 4-129) months. Patients receiving radiotherapy were younger and had a higher percentage of advanced pT category or perineural invasion than patients who did not. The estimated 5-year local recurrence-free survival rate was radiotherapy 92% with radiotherapy and 86% without. The disease-free survival rate was 55% with radiotherapy compared to 57% without and the overall survival rates were similar (63% vs. 68%, all P>0.05). In patients with a positive circumferential resection margin or insufficient distal resection margin, the local recurrence-free, disease-free, and overall survival rates were unaffected by radiotherapy.

CONCLUSIONS

The addition of postoperative radiotherapy to chemotherapy did not reduce the recurrence or mortality in node-positive rectal cancer when compared with chemotherapy alone. Moreover, this approach may not compensate for a positive circumferential resection margin or insufficient distal resection margin following rectal cancer surgery.

Chemoradiation for rectal cancer: rationale, approaches, and controversies

The standard adjuvant treatment of cT3 and/or N+ rectal cancer is preoperative chemoradiation. However, there are many controversies regarding this approach. These controversies include the role of short course radiation, whether postoperative adjuvant chemotherapy is necessary for all patients, and if the type of surgery following chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation, as well as modify the need for pelvic radiation? These questions and others remain active areas of clinical investigation.

Combined modality therapy for rectal cancer

The standard adjuvant treatment for cT3 and/or N+ rectal cancer is preoperative chemoradiation. However, there are many controversies regarding this approach. These include the role of short course radiation, whether postoperative adjuvant chemotherapy necessary for all patients and whether the type of surgery after chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation as well as modify the need for pelvic radiation? These questions and others remain active areas of clinical investigation.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.

Prognostic value of the lymph node ratio in stage III colorectal cancer: a systematic review

BACKGROUND

Although nodal invasion represents one of the most powerful prognostic indicators in colorectal cancer, marked heterogeneity exists within stage III patients. Recently, the lymph node ratio (LNR), defined as the ratio of the number of positive nodes over the total number of examined nodes, was proposed to stratify outcome in stage III patients.

METHODS

A systematic search was performed for studies examining the prognostic significance of the LNR in colon or rectal cancer. Individual studies were assessed for methodological quality and summary data extracted. Hazard ratios from multivariate analyses were entered in a fixed-effects meta-analysis model.

RESULTS

In total, 16 studies were identified including 33,984 patients with stage III colon or rectal cancer. In all identified studies, the LNR was identified as an independent prognostic factor in patients with stage III cancer of the colon or rectum. The prognostic separation obtained by the LNR was superior to that of the number of positive nodes (N stage). The pooled hazard ratios for overall and disease-free survival were 2.36 (95% confidence interval, 2.14-2.61) and 3.71 (95% confidence interval, 2.56-5.38), respectively.

CONCLUSIONS

The LNR allows superior prognostic stratification in stage III colorectal cancer and should be validated in prospective studies.

Staging and survival of rectal cancer in Vila Nova de Gaia, Portugal

INTRODUCTION

In the county of Vila Nova de Gaia (northern Portugal) in the period of 2004-2006, there were an average of 35 new cases of colorectal cancer per 100,000 population, which constitutes one of the highest rates in the world. The latest research has shown that there are many differences between colon and rectal cancers, thereby justifying an independent approach.

PATIENTS AND METHODS

The study pertained to the period 1995-2004, by using the census of 1991 and 2001 for calculating specific rates. The 399 diagnosed cases of rectal cancer were drawn from a specialized and active cancer registry, oncological registry of Gaia. Overall survival was calculated using the Kaplan-Meier method and the curves were compared using a Log Rank test. The effect of topography and histological type on survival was obtained by controlling the stage disease, using a Cox proportional hazards regression model.

RESULTS

There was a slight predominance of males, with a ratio between sexes of 1 : 3. The 50% overall survival rate after 5 years increased over time. The localization of the tumour and the histological type, after adjusting by stage, were not significant factors in the prognosis.

CONCLUSION

Our study shows an increase in the number of cases over time, particularly in elderly women. The cumulative risk of having rectal cancer remains unchanged from 1981 to 2004. Unlike other studies, an increase in early lesions was not observed.

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

PURPOSE

The sixth edition of the American Joint Committee on Cancer (AJCC) rectal cancer staging subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III as a result of improved survival with T1-2N2 versus T3-4N2 and survival of T4N1 more similar to T3-4N2 than T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion interacts with nodal status to affect survival.

METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 35,829 patients with rectal cancer were compared with rectal pooled analysis data (3,791 patients). T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of positive nodes as follows: N1a/N1b (one v two to three nodes) and N2a/N2b (four to six v > or = seven nodes). Five-year observed and relative survival rates were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2, T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2a have similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is better than T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based rectal cancer analysis validates the rectal pooled analyses and supports the shift of T1-2N2 lesions from IIIC to IIIA or IIIB and T4bN1 from IIIB to IIIC. SEER outcomes support subdividing T4, N1, and N2 and revised substaging of stages II and III. Survival by TN category suggests a complex biologic interaction between depth of invasion and nodal status.

Improved patient and regimen selection in locally advanced rectal cancer: who, how, and what next?

Before the advent of neoadjuvant chemoradiation therapy (NCRT) for locally advanced rectal cancer, local failure represented half of treatment failures. The German Rectal Cancer Study Group trial demonstrated that NCRT along with total mesorectal excision can improve local control and the rate of sphincter-preserving surgery. Thus, the National Comprehensive Cancer Network now recommends NCRT as the standard of care for stage III and IV rectal cancer. Recent trials and analysis have questioned accepted wisdom regarding patient selection for NCRT and methods of administration. EORTC 22921 demonstrated that the addition of chemotherapy to radiation therapy, regardless of timing, improved local control but not overall survival, and subgroup analysis from this study generated the hypothesis that the subgroup of patients with good pathologic response to NCRT would benefit the most from additional chemotherapy following surgery. The prognosis of rectal cancer is stage dependent, and 2 major analyses question whether T1/2 N1 and T3 N0 patients benefit from NCRT. Application of the results from these studies is hindered by imperfections in staging. Future improvement in patient selection might result from biologic analysis of tumor sensitivity. NCRT might be improved with the use of oral fluoropyrimidines and perhaps the addition of a second agent such as oxaliplatin, irinotecan, or cetuximab. Improvements in radiation, such as the use of more conformal techniques, might decrease the toxicity of therapy. Given the success of NCRT in improving local control, distant metastasis now predominates as the cause of treatment failure, and larger gains will likely be made from improvements in adjuvant chemotherapy.

Retrospective Long-Term Results and Prognostic Factors of Postoperative Treatment for UICC Stages II and III Rectal Cancer

Aims

To retrospectively evaluate 5-year local control, disease-free survival, cancer-specific survival and overall survival rates in patients with UICC stages II and III rectal cancer treated with adjuvant therapy and especially to analyze the impact of some prognostic factors on clinical outcome at univariate and multivariate analyses.

Methods and Materials

We retrospectively reviewed 306 patients treated with postoperative 5-fluorouracil-based chemoradiation (278 patients) or radiotherapy alone (28 patients) after curative surgery. The following prognostic factors were considered at univariate and multivariate analyses: age, sex, tumor location, surgery procedure, pathological stage, histology, tumor grade, surgical margins and radiotherapy technique.

Results

The 5-year actuarial rates for local control, disease-free survival, cancer-specific survival and overall survival were respectively 89.7%, 59.7%, 68.6% and 61.4% for the 278 patients (91%) treated with postoperative chemoradiation. Univariate analysis showed that abdominal-perineal resection impacted disease-free survival and that the T4 variable had an impact on cancer-specific survival and disease-free survival. Instead, age ≥70, N2, IIIB (p T3 p N1) and IIIC (pT3 p N2) stage impacted cancer-specific survival, disease-free survival and rate of distant metastases. Multivariate analysis showed as significant variables age ≥70 years, pN1 and pN2 and extraperitoneal tumor location.

Conclusions

Our retrospective study showed a good 5-year local control. Factors such as individual pT4, pN1, pN2, age ≥70 years, abdominal-perineal resection, stages IIIB-IIIC versus II-IIIA and extraperitoneal tumor location negatively influenced disease-free survival, distant metastases and cancer-specific survival. Differences exist between stages II and III rectal cancer and treatment modulation and intensification are required in order to offer the most appropriate and effective adjuvant treatment and to improve survival of rectal cancer patients.

Assessment of K-ras mutation: a step toward personalized medicine for patients with colorectal cancer

Some of the most significant therapeutic advances in the treatment of cancer have occurred in the management of colorectal metastases. The introduction of new cytotoxic chemotherapeutic and biologic agents has changed the approach to these patients from both an oncologic and a surgical perspective. In addition, an understanding of the molecular mechanisms by which these agents affect tumors is developing. This molecular information will be critical in the future in designing therapeutic regimens based on an individual tumor's genetic profile rather than treatment for a specific tumor type. The rapidly evolving treatment of colon cancer has provided several interesting genetic biomarkers/pathways/genes-/kinases that have been targeted or seem to play an important role. Of particular interest is the blockade of epidermal growth factor receptor (EGFR) with monoclonal antibodies. This treatment is efficacious when used alone or combined with chemotherapy. However, recent data revealed that patients with tumors positive for the K-ras mutation do not benefit from EGFR blockade. Compelling evidence has indicated that mutated K-ras is an important oncogene involved at the early stage of the development of colorectal cancer. Furthermore, mutations in the K-ras gene have been associated with aggressive tumor biology. K-ras mutational analysis is an important step in the overarching goal of developing personalized medicine. New treatment strategies are needed to more effectively treat patients with the K-ras mutation.

The influence of the number of retrieved lymph nodes on staging and survival in patients with stage II and III rectal cancer undergoing tumor-specific mesorectal excision

OBJECTIVE

This study was designed to determine whether the number of lymph nodes retrieved influence staging and survival in patients with stage II and III rectal cancer that undergo tumor-specific mesorectal excision.

SUMMARY BACKGROUND DATA

The prognostic impact of the retrieved nodes has been emphasized in patients with colorectal cancer, but few studies have focused on patients with rectal cancer.

METHODS

A total of 900 patients who underwent tumor-specific mesorectal excision with curative intent and adjuvant chemoradiation therapy for stage II and III rectal cancer from January 1989 to December 2006 were analyzed.

RESULTS

Cancer-specific survival (CSS) of stage II patients with less than 15 nodes (25th percentile) was not different from stage III patients, but CSS was better in stage II patients with more than 15 nodes. When using cutoff values of the 25th and 50th percentiles (22 and 31 nodes), recurrence-free survival (RFS) was statistically different among subgroups of stage II and III patients. In multivariate analysis, stage II disease with less than 15 nodes retrieved was an adverse factor for CSS and RFS. In Kaplan-Meier survival analysis, using cutoff values, the difference for CSS was not significant with 22 and more nodes and the difference for RFS was not observed with 23 and more nodes.

CONCLUSIONS

The number of lymph nodes retrieved is closely associated with survival and recurrence in patients with stage II rectal cancer and, for more accurate prognostic stratification, at least 22 and 23 nodes seem to be necessary, respectively, for CSS and for RFS.

Prognostic heterogeneity of endosonographic T3 rectal cancer

PURPOSE

This study aimed to assess the prognostic implications of uT3 rectal carcinomas according to the tumor thickness and to analyze the correlation between this ultrasound-based parameter and other prognostic factors.

METHODS

Seventy-four patients with uT3(pM0) rectal tumors underwent primary surgery from 1996 to 2003. Preoperative endorectal ultrasound was used to assess uN stage, maximum tumor perimeter, and maximum tumor thickness. An ultrasound maximum tumor thickness cutoff point for local recurrence subdividing T3 tumors into uT3a and uT3b was established.

RESULTS

Median follow-up was 41 months (range, 24-59). The 5-year actuarial local and overall recurrence rates were 9.82 percent (n = 7) and 42.46 percent (n = 23), respectively. uN stage(P = 0.05), circumferential resection margin involvement (P = 0.002), an ultrasound maximum tumor thickness (P = 0.01), and locally advanced tumors (P = 0.001) were related to a significantly increased risk of local recurrence. An ultrasound maximum tumor thickness (hazard ratio, 1.15; 95 percent confidence interval, 1.0-1.2) and locally advanced tumor (hazard ratio, 17.21; 95 percent confidence interval, 2.99-98.84) were preoperative independent variables for predicting local recurrence. Locally advanced tumor was the only preoperative independent prognostic factor for overall recurrence (P = 0.004; hazard ratio, 1.09; 95 percent confidence interval, 1.0-1.1). An ultrasound maximum tumor thickness with a 19-mm cutoff point, subdividing the T3 tumors into uT3a and uT3b, can be used to predict local recurrence. Locally advanced tumors (P = 0.02) and circumferential resection margin involvement (P = 0.005) showed a significant association with an ultrasound maximum tumor thickness >19 mm.

CONCLUSIONS

A maximum tumor thickness measured by endorectal ultrasound in pT3 rectal cancer is an independent prognostic factor for local and overall recurrence. An ultrasound maximum tumor thickness cutoff point of 19 mm may be useful to classify patients preoperatively and to select them for primary surgery or neoadjuvant therapy.

Postoperative radiotherapy for stage IIIA rectal cancer: is it justified?

PURPOSE

Adjuvant radiotherapy is currently recommended for all node-positive rectal cancers to reduce local recurrence. This study evaluated if an adequate mesorectal excision can obviate the need for radiotherapy in early node-positive cancer.

METHODS

Stage IIIA rectal cancer patients were identified in a prospectively maintained database. Patients who received postoperative radiotherapy (radiotherapy) and those who did not (no radiotherapy) were compared for recurrence, survival, bowel function, and quality of life. Quality of life was assessed using the Short Form-36 Medical Outcomes Survey.

RESULTS

Eighty-six patients underwent proctectomy for T1-T2,N1 rectal cancers from 1978 to 2004. Patients receiving radiotherapy (n = 34) were younger and had a higher percentage of T1 tumors than patients who did not receive radiotherapy (n = 52). Other tumor characteristics, type of surgery, and number of involved lymph nodes were comparable. Estimated 5-year local recurrence was radiotherapy 3.4 percent and no radiotherapy 4.7 percent; distant recurrence was radiotherapy 13.5 percent and no radiotherapy 16.5 percent; and disease-specific mortality rates were similar 13.5 vs. 11.3 percent, for radiotherapy and no radiotherapy (all P > .05). Patients receiving radiotherapy had higher frequency of daytime bowel movements, urgency, and usage of pads and antidiarrheal medications. Age adjusted quality of life parameters were comparable between treatments.

CONCLUSION

Postoperative radiotherapy did not reduce recurrence or mortality. Function but not quality of life was adversely affected. Routine postoperative radiotherapy for Stage IIIA rectal cancer should be reconsidered.

Getting adequate information across to colorectal cancer screening subjects can be difficult

Objectives

Participation in screening should be the outcome of an informed decision. We evaluated whether invitees in the first Dutch colorectal cancer (CRC) screening programme were adequately informed after having received a detailed information leaflet.

Methods

A total of 20,623 subjects aged 50–75 years were invited to the fecal occult blood test (FOBT) screening programme. All received a detailed information leaflet by mail between May 2006 and January 2007. After two weeks, a reminder letter was sent to all invitees, accompanied by a survey on CRC and screening.

Results

The survey was completed by 9594 invitees (47%). Almost all responders (99%) found the leaflet clear and readable. Almost all indicated that CRC can be treated better if found early (99%). Only 20% of the responders answered all knowledge-related answers correctly. Almost half of the responders (47%) believed that a negative FOBT excludes the presence of CRC. Older age and having a positive family member for CRC were correctly identified as risk factors by 80%.

Conclusion

This study demonstrates that although an information leaflet was reported as being clear and readable, the information provided in it was not always understood well. This suggests that other educational options should be investigated in order to improve general knowledge of CRC in screening invitees.

Systemic treatment of colorectal cancer

Colorectal cancer is the fourth most common noncutaneous malignancy in the United States and the second most frequent cause of cancer-related death. Over the past 12 years, significant progress has been made in the systemic treatment of this malignant condition. Six new chemotherapeutic agents have been introduced, increasing median overall survival for patients with metastatic colorectal cancer from less than 9 months with no treatment to approximately 24 months. For patients with stage III (lymph node positive) colon cancer, an overall survival benefit for fluorouracil-based chemotherapy has been firmly established, and recent data have shown further efficacy for the inclusion of oxaliplatin in such adjuvant treatment programs. For patients with stage II colon cancer, the use of adjuvant chemotherapy remains controversial, but may be appropriate in a subset of individuals at higher risk for disease recurrence. Ongoing randomized clinical trials are evaluating how best to combine currently available therapies, while smaller studies are evaluating new agents, with the goal of continued progress in prolonging life among patients with metastatic colorectal cancer and increasing cure rates among those with resectable disease.

Survival benefits and trends in use of adjuvant therapy among elderly stage II and III rectal cancer patients in the general population

BACKGROUND

This study examined elderly stage II and III rectal cancer patients' adjuvant chemoradiation therapy adherence, trends in adherence over time, and the relation of levels of adherence to mortality.

METHODS

The authors studied 2886 stage II and III rectal cancer patients who had surgical resection and who appeared in 1992-1999 linked SEER-Medicare claims data. The authors compared measures of adjuvant radiation and chemotherapy receipt and completion between stage II and III patients. Adjusted risk of cancer-related 5-year mortality was calculated by multivariate logistic regression for different levels of chemoradiation adherence among stage II and III patients.

RESULTS

Of the 2886 patients, 45.4% received both adjuvant radiation and chemotherapy. Stage III patients were more likely to receive chemoradiation than stage II patients. The receipt of chemoradiation by stage II patients increased significantly from 1992 to 1999. Stage III patients were more likely to complete radiation therapy (96.6%), chemotherapy (68.2%), and both modalities (67.5%) than stage II patients (91.5%, 49.8%, 47.6%, respectively). Only a complete course of both radiation and chemotherapy for both stage II (relative risk [RR] 0.74; 95% CI, 0.54, 0.97) and III (RR 0.80; 95% CI, 0.65, 0.96) decreased the adjusted 5-year cancer mortality risk compared with counterparts with no adjuvant therapy.

CONCLUSIONS

Even though stage II rectal cancer patients were less likely than stage III patients to receive and complete adjuvant chemoradiation, both patient groups in the general population had lower cancer-related mortality if they completed chemoradiation. These patients deserve support and encouragement to complete treatment.

Adjuvant and neoadjuvant chemoradiation or radiotherapy in rectal cancer--a review focusing on open questions

BACKGROUND

The therapy of rectal cancer has been a matter of debate since decades, especially with regard to the benefits of neoadjuvant or adjuvant therapies. Principles of additional therapies have been established nearly two decades ago and are questioned nowadays on the basis of more recently modified operative techniques. Benefits and sequelae of therapies have to be balanced against each other, and it seems somewhat likely that a more differentiated strategy than simply stating that every patient with stage II and III rectal cancer needs chemoradiation or radiotherapy will, in long term, be recommended.

CONCLUSION

It should be kept in mind that results of centers of excellence and of phase-III studies with their positively selected patient populations are not representative for all the patients with rectal cancer and physicians treating them.

cT3N0 rectal cancer: potential overtreatment with preoperative chemoradiotherapy is warranted

PURPOSE

Although combined-modality therapy (CMT) is the preferred treatment for T3 and/or lymph node (LN)-positive rectal cancer, the German rectal cancer study published in 2004 demonstrated that 18% of patients deemed suitable for preoperative CMT by endorectal ultrasound (ERUS) may be overstaged. Because data also suggest that LN-negative rectal cancer after total mesorectal excision may not require radiotherapy, it is reasonable to consider omitting radiotherapy for the cT3N0 subset. We therefore determined the accuracy of pre-CMT ERUS or magnetic resonance imaging (MRI) staging, to explore the validity of a nonpreoperative CMT approach for cT3N0 disease.

PATIENTS AND METHODS

One hundred eighty-eight ERUS-/MRI-staged T3N0 rectal cancer patients received preoperative CMT (fluorouracil based and 45-50.4 Gy) followed by radical resection. Rates of pathologic complete response (pCR) and mesorectal LN involvement were determined.

RESULTS

Tumors were located a median of 5 cm from the anal verge. Sphincter-preserving surgery was performed in 143 patients (76%). Overall pCR was 20%, and 41 patients (22%) had pathologically positive mesorectal LNs. The incidence of positive LNs significantly increased with T stage: ypT0, 3%; ypT1, 7%; ypT2, 20%; ypT3-4, 36% (P = .001).

CONCLUSION

The accuracy of preoperative ERUS/MRI for staging mid to distal cT3N0 rectal cancer is limited because 22% of patients have undetected mesorectal LN involvement despite CMT. Therefore, ERUS-/MRI-staged T3N0 rectal cancer patients should continue to receive preoperative CMT. Although 18% may be overstaged and therefore overtreated, our data suggest that an even larger number would be understaged and require postoperative CMT, which is associated with significantly inferior local control, higher toxicity, and worse functional outcome.

No prognostic impact of isolated lymphovascular invasion after radical resection of rectal cancer--results of a multicenter observational study

BACKGROUND

The prognostic impact of isolated lymphovascular invasion (LVI) after radical resection of rectal cancer is controversially discussed. However, it could be relevant to decide for an adjuvant treatment.

AIM

The aim of the analysis was, based on the data of an observational study, to determine the prognostic relevance of the isolated LVI.

MATERIALS AND METHODS

Patients after radical resection of rectal cancer with no hemangioinvasion were subdivided in three groups: I-no LVI, no lymph node metastases (LNM); II-positive LVI, no LNM; III-positive LNM. Five-year local recurrence rate, distant metastases-free and disease-free survival were determined uni- and multivariate.

RESULTS

Patients, n = 846, were studied (I, n = 471; II, n = 75; III, n = 300). The univariate comparison between the groups revealed the following 5-year results: local recurrence rate: 9.4 vs 10.0 vs 14.0%; distant metastases-free survival: 84.1 vs 82.5 vs 49.3%; disease-free survival: 83.2 vs 80.7 vs 45.5%. The differences between groups I and III were significant, but not between groups I and II. The determined higher disease-free survival rate in group II vs group III was significant (P = 0.041), but the differences in local recurrence rate and rate of distant metastases did not reach statistical significance. The multivariate analysis revealed no impact of the isolated LVI on the oncological outcome.

CONCLUSION

The isolated LVI has no independent prognostic impact on the local recurrence rate and long-term survival after radical resection of rectal cancer. Based on this finding, no indication for an adjuvant treatment in these patients can be derived.