Pre-operative chemo-radiotherapy improves the sphincter preservation rate in patients with rectal cancer located within 3 cm of the anal verge

Local Excision Versus Total Mesorectal Excision After Favourable Response to Neoadjuvant Therapy in Low Rectal Cancer: a Multi-centre Experience

The gold standard surgical management of curable rectal cancer is proctectomy with total mesorectal excision. Adding preoperative radiotherapy improved local control. The promising results of neoadjuvant chemoradiotherapy raised the hopes for conservative, yet oncologically safe management, probably using local excision technique. This study is a prospective comparative phase III study, where 46 rectal cancer patients were recruited from patients attending Oncology Centre of Mansoura University and Queen Alexandra Hospital Portsmouth University Hospital NHS with a median follow-up 36 months. The two recruited groups were as follows: group (A), 18 patients who underwent conventional radical surgery by TME; and group (B), 28 patients who underwent trans-anal endoscopic local excision. Patients of resectable low rectal cancer (below 10 cms from anal verge) with sphincter saving procedures were included: cT1-T3N0. The median operative time for LE was 120 min versus 300 in TME (p < 0.001), and median blood loss was 20 ml versus 100 ml in LE and TME, respectively (p < 0.001). Median hospital stay was 3.5 days versus 6.5 days (p = 0.009). No statistically significant difference in median DFS (64.2 months for LE versus 63.2 months for TME, p = 0.85) and median OS (72.9 months for LE versus 76.3 months for TME, p = 0.43). No statistically significant difference in LARS scores and QoL was observed between LE and TME (p = 0.798, p = 0.799). LE seems a good alternative to radical rectal resection in carefully selected responders to neoadjuvant therapy after thorough pre-operative evaluation, planning and patient counselling.

Effect of pathological complete response after neoadjuvant chemoradiotherapy on postoperative complications of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Standard total mesorectal resection has become an important treatment option for locally advanced or high-risk rectal cancer after neoadjuvant chemo-radiotherapy. 15-27% of patients can achieve pathological complete response (PCR) after neoadjuvant chemo-radiotherapy (nCRT). However, the relationship between PCR and postoperative complications remains an important unsolved problem. The objective of this study was to determine whether PCR was associated with the rate of postoperative complications.

METHODS

This meta-analysis was implemented following the recommendations from Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched electronic literature by PubMed, EMBASE, and Google Scholar. Major outcomes of interest included anastomotic leakage, surgical-site infection, reoperation, and any postoperative complications. Other outcomes comprised postoperative hemorrhage, ileus, and mortality.

RESULTS

Eleven thousand two hundred ninety patients in 9 studies were included in the meta-analysis. The pooled analysis revealed that patients with PCR did not have a higher risk of anastomotic leakage (OR = 1.22, 95% CI 0.92-1.62, p = 0.17), reoperation (OR = 1.13, 95% CI 0.93-1.37, p = 0.22), and any postoperative complications (OR = 1.02, 95% CI 0.91-1.15, p = 0.72) than patients with non-PCR. However, the meta-analysis showed that the PCR group was superior to the non-PCR group in terms of surgical-site infection (9.38% vs. 12.44%OR = 0.68, 95% CI 0.47-0.98; p = 0.04).

CONCLUSION

PCR might not be related to the occurrence of postoperative complications in rectal cancer patients following nCRT. In addition, PCR might be associated with a lower risk of surgical-site infection.

Time interval between the completion of radiotherapy and robotic-assisted surgery among patients with stage I-III rectal cancer undergoing preoperative chemoradiotherapy

BACKGROUND

This aim of this study was to evaluate the effects of time interval between the completion of radiotherapy and robotic-assisted surgery on the outcomes among patients with rectal cancer undergoing preoperative concurrent chemoradiotherapy (CCRT).

METHODS

In total, 116 patients with stage I-III rectal cancer who underwent preoperative CCRT and robotic-assisted surgery between September 2013 and February 2019 were enrolled. Patients were categorized into two groups based on the time interval: group A (10-12 weeks) and group B (≥ 12 weeks).

RESULTS

Among the 116 enrolled patients, 98 (84.5%) had middle and lower rectal cancers. Two (1.7%) patients underwent abdominoperineal resection with a sphincter preservation rate of 98.3%. Thirty-seven (31.9%) patients had a pathologic complete response (pCR). The circumferential resection margin and distal resection margin were positive in 2 (1.7%) and 1 (0.9%) patients, respectively. Therefore, the R0 resection rate was 97.4%. A total of 24 (22.4%) patients experienced postoperative relapse and 12 (10.3%) patients died; these were slightly more common in group B than in group A (28.8% vs 15.8% and 15.3% vs 5.3%, respectively; both P > 0.05); however, this difference was nonsignificant. Three-year disease-free survival (DFS) and overall survival (OS) were 75% and 89%, respectively, among all patients. Non-significant trend of favorable 3-year DFS, 3-year OS, 3-year locoregional control rate and 3-year distant metastasis control rate were observed in group A compared with group B (all P > 0.05).

CONCLUSION

Robotic-assisted surgery after a longer interval is safe and feasible for patients with rectal cancer undergoing preoperative CCRT. The present study's results suggested that the time interval of 10-12 weeks can be considered because comparable clinical and perioperative outcomes and preferable oncological outcomes were observed for interval of this length. However, future prospective randomized clinical trials are required to verify the present finding.

Neoadjuvant chemoradiotherapy might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer: A retrospective single-institution study with propensity score-matched comparative analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME) are standard treatments of stage II/III locally advanced rectal cancer (LARC), currently. Here, we evaluated the oncological outcomes in LARC patients treated with NACRT compared to TME alone, and determined whether tumor regression grade (TRG) and pathologic response after NACRT was related to prognosis.

METHODS

This is a retrospective comparison of 358 LARC patients treated with either TME alone (non-NACRT group, n = 173) or NACRT plus TME (NACRT group, n = 185) during 2003-2013. Perioperative and oncologic outcomes, like overall survival (OS), disease-free survival (DFS) and recurrence were compared using 1:1 propensity score matching analysis.

RESULTS

A total of 133 patients were matched for the analysis. After a median follow-up of 45 months (8-97 months), the 5-year OS (NACRT vs non-NACRT: 75.42% vs 72.76%; P = 0.594) and 5-year DFS (NACRT vs non-NACRT: 74.25% vs 70.13%; P = 0.224) were comparable between NACRT and non-NACRT, whereas the 5-year DFS rate was higher in the NACRT group when only stage IIIb/IIIc patients were considered (NACRT vs. non-NACRT: 74.79% vs. 62.29%; P = 0.056). In the NACRT group of 185 patients, those with pCR/stage I (vs stage II/stage III disease) or TRG3/TRG4 disease (vs TRG0/TRG1/TRG2) had significantly better prognosis.

CONCLUSION

NACRT might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer.

Surgical treatment following neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Colorectal cancer is a major public health problem worldwide, and locally advanced rectal cancer (LARC) is known for its poor prognosis. A multimodal treatment approach is the only method to achieve satisfactory local recurrence and survival rates in LARC. Determining which therapeutic modality for LARC has the most satisfactory influence on quality of life and disease outcome is still controversial. LARC treatment is subject to continuous advancement due to the development of new and better diagnostic tools, radiotherapy techniques, and chemotherapeutic agents. Herein, we review various therapeutic modalities for LARC from several aspects. In addition to radiotherapy techniques such as neoadjuvant chemoradiotherapy (NCRT), we discuss the progress of chemotherapy, appropriate time interval between NCRT and surgery, relationship between tumor location and NCRT efficacy/safety, wait-and-watch policy, and predictors of treatment response following NCRT. Because of the controversies and unanswered questions regarding NCRT treatments for LARC, additional investigations are required to determine which therapeutic approach is the most feasible for LARC patients.

Neoadjuvant volumetric modulated arc therapy in rectal cancer and the correlation of pathological response with diffusion-weighted MRI and apoptotic markers

PURPOSE

In this prospective observational study, we aimed to report the applicability and tolerability of neoadjuvant volumetric modulated arc therapy with simultaneous integrated boost (SIB-VMAT) and concurrent chemotherapy in patients with locally advanced rectal cancer (LARC), and to evaluate the correlation of pathological response with apparent diffusion coefficient (ADC) measurements on diffusion-weighted magnetic resonance imaging (DW-MRI) and apoptotic markers.

METHODS

The study enrolled 30 patients with T3 to T4 and/or N+ rectal cancer who preoperatively received SIB-VMAT and concurrent chemotherapy. Before and after the neoadjuvant treatment, apoptotic markers including the nucleosomes and cell-free DNA fragments in the serum samples were examined; DNA integrity was assessed by amplifying the ACTB gene; and the ADC measurements on the DW-MRI were analyzed.

RESULTS

No patients had acute or chronic grade III-IV toxicity. Pathologic complete response (pCR) was achieved in 8 patients (27%), while in 10 patients (33%) near-complete pathological response was obtained. Posttreatment ADC was significantly higher in patients with pCR compared with the others (1.28 vs. 1.10, p = 0.017). ROC curve analysis showed that posttreatment ADC values had a sensitivity of 75% and a specificity of 77.3% for distinguishing the patients with pCR from other responders. On the other hand, posttreatment DNA integrity values were revealed lower than the pretreatment values (p = 0.36). Also, the results revealed an insignificant increase in the posttreatment serum level of nucleosomes (p = 0.72).

CONCLUSIONS

Neoadjuvant SIB-VMAT with concurrent chemotherapy was proved to be a feasible treatment regimen in LARC with tolerable side effects, and improved local control rate and pCR rate.

Predictors of Sensitivity to Preoperative Chemoradiotherapy of Rectal Adenocarcinoma

Objectives

The purpose of the study was to identify predictive factors of tumor response to preoperative chemoradiotherapy for rectal adenocarcinoma.

Methods

Ninety-eight patients with nonmetastatic rectal adenocarcinoma received preoperative concurrent chemoradiotherapy and underwent mesorectal excision. After treatment, tumor response according to tumor regression grade were evaluated. The correlation of clinicopathologic factors to tumor response was analyzed.

Results

The results from a univariate analysis indicated that pretreatment carcinoembryonic antigen level ≤3.0 ng/ml (P = 0.002), non-fixed tumor (P = 0.001), and tumor circumferential extent ≤50% (P = 0.001) were associated significantly with a good tumor response. They also indicated that pretreatment positive lymph nodes (P = 0.032) were associated significantly with a poor tumor response. In multivariate analysis, the results indicated that pretreatment carcinoembryonic antigen level (hazard ratio, 2.930; P = 0.003), tumor mobility (hazard ratio, 2.651; P = 0.002) and circumferential extent of tumor (hazard ratio, 2.394; P = 0.019) independently predicted a good pathologic response rate. Pretreatment positive lymph nodes were not significantly associated with a good response (hazard ratio, 0.361; P = 0.191).

Conclusions

Pretreatment carcinoembryonic antigen level, tumor mobility and circumferential extent of tumor may be helpful in predicting responsiveness in rectal adenocarcinoma to preoperative chemoradiotherapy, although the results should be confirmed in larger, more homogeneous studies.

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.

Locally advanced rectal cancer: post-chemoradiotherapy ADC histogram analysis for predicting a complete response

BACKGROUND

The value of diffusion-weighted imaging (DWI) for reliable differentiation between pathologic complete response (pCR) and residual tumor is still unclear. Recently, a few studies reported that histogram analysis can be helpful to monitor the therapeutic response in various cancer research.

PURPOSE

To investigate whether post-chemoradiotherapy (CRT) apparent diffusion coefficient (ADC) histogram analysis can be helpful to predict a pCR in locally advanced rectal cancer (LARC).

MATERIAL AND METHODS

Fifty patients who underwent preoperative CRT followed by surgery were enrolled in this retrospective study, non-pCR (n = 41) and pCR (n = 9), respectively. ADC histogram analysis encompassing the whole tumor was performed on two post-CRT ADC600 and ADC1000 (b factors 0, 600 vs. 0, 1000 s/mm(2)) maps. Mean, minimum, maximum, SD, mode, 10th, 25th, 50th, 75th, 90th percentile ADCs, skewness, and kurtosis were derived. Diagnostic performance for predicting pCR was evaluated and compared.

RESULTS

On both maps, 10th and 25th ADCs showed better diagnostic performance than that using mean ADC. Tenth percentile ADCs revealed the best diagnostic performance on both ADC600 (AZ 0.841, sensitivity 100%, specificity 70.7%) and ADC1000 (AZ 0.821, sensitivity 77.8%, specificity 87.8%) maps. In comparison between 10th percentile and mean ADC, the specificity was significantly improved on both ADC600 (70.7% vs. 53.7%; P = 0.031) and ADC1000 (87.8% vs. 73.2%; P = 0.039) maps.

CONCLUSION

Post-CRT ADC histogram analysis is helpful for predicting pCR in LARC, especially, in improving the specificity, compared with mean ADC.

Impact of Total Lymph Node Count on Staging and Survival After Neoadjuvant Chemoradiation Therapy for Rectal Cancer

PURPOSE

Current guidelines recommend that a minimum of 12 lymph nodes (LNs) be dissected to accurately stage rectal cancer patients. Neoadjuvant chemoradiation therapy (CRT) decreases the number of LNs retrieved at surgery. The purpose of this study was to assess the impact of the number of LNs dissected on overall survival (OS) for localized rectal cancer patients treated with neoadjuvant CRT.

METHODS

Treatment data were obtained on all patients treated for rectal cancer (2000-2013) in the National Oncology Data Alliance™, a proprietary database of merged tumor registries. Eligible patients were treated with neoadjuvant CRT followed by surgery and had complete data on number of positive LNs, number of LNs examined, and treatment dates (n = 4565).

RESULTS

Hazard ratios for OS decreased sequentially with increasing number of LNs examined until a maximum benefit was achieved with examination of eight LNs. On multivariate analysis, age, sex, race, marital status, grade, ypT stage, ypN stage, type of surgery, margin status, presence of pathologically confirmed metastasis at surgery, and number of LNs examined were significant predictors of OS.

CONCLUSIONS

Examination of eight or more LNs in rectal cancer patients treated with neoadjuvant CRT resulted in accurate staging and assignment into prognostic groups with an ensuing improvement in OS by stage. This study suggests that eight LNs is the threshold for an adequate lymph node dissection after neoadjuvant CRT.

Identification of locally advanced rectal cancer with low risk of local recurrence

Background

The routine application of neoadjuvant chemoradiotherapy for T3N0 rectal cancer remains controversial. The aim of this study was to use clinical, Magnetic resonance imaging, and pathological parameters to identify a subgroup of patients with low risk of local recurrence who might be precluded from neoadjuvant chemoradiotherapy.

Methods

We retrospectively reviewed a prospectively maintained database of consecutive rectal cancer patients who underwent curative resection. 166 pathologic confirmed T3N0 rectal cancer patients with tumor located 5–12cm above the anal verge and preoperative circumferential resection margin>1mm were included in analysis. The primary outcomes measured were3- and 5-year local recurrence rates.

Results

Local recurrence was demonstrated during follow-up in 5 patients; the actuarial overall 3- and 5-year local recurrence rates were 2.5% and 3.4%, respectively. Inadequate sampling of lymph nodes (≤12) was associated with higher local recurrence (P = 0.03) in this group of patients.

Conclusion

For upper and middle T3N0 rectal cancer with preoperative circumferential resection margin>1mm, local recurrence rate after total mesorectal excision is low and surgery alone may be enough for this group of patients.

Sphincter preservation in distal CT2N0 rectal cancer after preoperative chemoradiotherapy

BACKGROUND

Preoperative chemoradiotherapy is usually not indicated for cT2N0 rectal cancer. Abdominoperineal resection is the standard treatment for distal rectal tumors. The aim of the study was to evaluate the actual sphincter-preservation rate in patients with distal cT2N0 rectal cancer given neoadjuvant chemoradiotherapy.

METHODS

Data were retrospectively collected for all patients who were diagnosed with distal cT2N0 rectal cancer at a tertiary medical center in 2000-2008 and received chemoradiotherapy followed by surgery (5-7 weeks later).

RESULTS

Thirty-three patients (22 male) of median age 65 years (range, 32-88) were identified. Tumor distance from the anal verge ranged from 0 to 5 cm. R0 resection with sphincter preservation was accomplished in 22 patients (66%), with a 22% pathological complete response rate. Median follow-up time was 62 months (range 7-120). There were no local failures. Crude disease-free and overall survival were 82% and 86%, respectively. Factors associated with sphincter preservation were tumor location (OR=0.58, p=0.02, 95% CI=0.37-0.91) and pathological downstaging (OR=7.8, p=0.02, 95% CI=1.35-45.85). Chemoradiotherapy was well tolerated.

CONCLUSION

High rates of sphincter preservation can be achieved after preoperative chemoradiotherapy for distal cT2N0 rectal cancer, with tolerable toxicity, without compromising oncological outcome.

Interval to surgery after neoadjuvant treatment for colorectal cancer

The current standard treatment of low-lying locally advanced rectal cancer consists of chemoradiation followed by radical surgery. The interval between chemoradiation and surgery varied for many years until the 1999 Lyon R90-01 trial which compared the effects of a short (2-wk) and long (6-wk) interval. Results showed a better clinical tumor response (71.7% vs 53.1%) and higher rate of positive and pathologic tumor regression (26% vs 10.3%) after the longer interval. Accordingly, a 6-wk interval between chemoradiation and surgery was set to balance the oncological results with the surgical complexity. However, several recent retrospective studies reported that prolonging the interval beyond 8 or even 12 wk may lead to significantly higher rates of tumor downstaging and pathologic complete response. This in turn, according to some reports, may improve overall and disease-free survival, without increasing the surgical difficulty or complications. This work reviews the data on the effect of different intervals, derived mostly from retrospective analyses using a wide variation of treatment protocols. Prospective randomized trials are currently ongoing.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

Clinical impact of fat clearing technique in nodal staging of rectal cancer after preoperative chemoradiotherapy

Purpose

This study was designed to evaluate the efficacy of a fat clearing technique for accurate nodal staging of rectal cancer patients after preoperative chemoradiotherapy (CRT).

Methods

A total of 19 patients with rectal cancer within 10 cm from anal verge were divided into two groups: non-CRT group (n = 10) and CRT group (n = 9). For pathologic assessment, lymph node (LN) harvest was performed using conventional manual dissection followed by a fat clearing technique.

Results

A median of 3.0 additional LNs in non-CRT group and 3.8 LNs in CRT group were identified by the fat clearing technique. When subanalysis was performed in patients with fewer than 12 retrieved LNs, a median of 4.0 extra LNs in non-CRT group and 3.5 extra LNs in CRT group were identified after the fat clearing technique. None of additionally identified nodes were metastatic. In both groups, the median size of retrieved LNs following the fat clearing technique was smaller than that obtained by manual dissection (2.0 mm vs. 3.0 mm, P < 0.001).

Conclusion

The fat clearing technique allowed detection of additional LNs that were missed by the manual method, but these detected LNs were not proven to be metastatic.

Sphincter-preserving surgery after preoperative radiochemotherapy for T3 low rectal cancers

The aim of this study was to evaluate the feasibility and the effectiveness of preoperative radiochemotherapy followed by total mesorectal excision (TME) and sphincter-preserving procedures for T3 low rectal cancer. Patients with rectal cancer and T3 tumors located within 1-6 cm of the dentate line received preoperative radiochemotherapy. Concurrent 5-fluorouracil-based radiochemotherapy was used. Radical resection with TME and sphincter-preserving procedures were performed during the six to eight weeks following radiotherapy. Survival was analyzed using the Kaplan-Meier method. The anal function was evaluated using the Wexner score. The clinical response rate was 83.5%, overall downstaging of T classification was 75.3% and pathological complete response was 15.3%. The anastomotic fistula rate was 4.7%. A median follow-up of 30 months showed the local recurrence rate to be 4.7% and the distant metastasis rate to be 5.9%. The three-year overall survival rate was 87%. The degree of anal incontinence as measured using the Wexner score decreased over time, and the anal sphincter function in the majority of patients gradually improved. Preoperative radiochemotherapy was found to improve tumor downstaging, reduces local recurrence, increase the sphincter preservation rate, and is therefore of benefit to patients with T3 low rectal cancer.

The CARTS study: Chemoradiation therapy for rectal cancer in the distal rectum followed by organ-sparing transanal endoscopic microsurgery

Background

The CARTS study is a multicenter feasibility study, investigating the role of rectum saving surgery for distal rectal cancer.

Methods/Design

Patients with a clinical T1-3 N0 M0 rectal adenocarcinoma below 10 cm from the anal verge will receive neoadjuvant chemoradiation therapy (25 fractions of 2 Gy with concurrent capecitabine). Transanal Endoscopic Microsurgery (TEM) will be performed 8 - 10 weeks after the end of the preoperative treatment depending on the clinical response.

Primary objective is to determine the number of patients with a (near) complete pathological response after chemoradiation therapy and TEM. Secondary objectives are the local recurrence rate and quality of life after this combined therapeutic modality. A three-step analysis will be performed after 20, 33 and 55 patients to ensure the feasibility of this treatment protocol.

Discussion

The CARTS-study is one of the first prospective multicentre trials to investigate the role of a rectum saving treatment modality using chemoradiation therapy and local excision. The CARTS study is registered at clinicaltrials.gov (NCT01273051)

Prognostic value of Smac expression in rectal cancer patients treated with neoadjuvant therapy

The objective was to evaluate expression of second mitochondria-derived activator of caspase (Smac) expression before and after treatment in patients treated with preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer and to correlate the clinicopathological characteristics and level of Smac expression with pathologic response and outcome. Expression of biomarker was evaluated by immunohistochemistry in tumor samples from 98 patients with clinical Stage II and III rectal cancer treated with preoperative pelvic radiotherapy plus concurrent chemotherapy. All patients received a standardized total mesorectal excision procedure after a long interval of 4-6 weeks. For Smac, patients with a good response to neoadjuvant CRT tended to have higher pre-therapy levels (P = 0.007). The level of Smac expression decreased after neoadjuvant therapy (P = 0.016). High expression of Smac before CRT, and high Dworak's tumor regression grade (TRG) were significantly associated with improved 5-year disease-free survival (P < 0.05). Pretreatment nodal status also was significantly associated with 5-year disease-free survival and 5-year local relapse-free survival (P < 0.05). Multivariate analysis confirmed that the pretreatment expression of Smac and Lymph nodal status were independent prognostic factors. Our study suggests that high expression of Smac before neoadjuvant CRT could predict good outcome in locally advanced rectal cancer patients.

Predictive value of Smac, VEGF and Ki-67 in rectal cancer treated with neoadjuvant therapy

The present study aimed to identify whether second mitochondria-derived activator of caspase (Smac), vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (Ki-67) expression in pre-treatment tumor biopsies are useful predictive markers of tumor response in patients with rectal cancer undergoing pre-operative chemoradiotherapy (CRT). Paraffin-embedded tissues obtained before and after therapy were evaluated by immunohistochemical staining for Smac, VEGF and Ki-67. The study evaluated the correlation of Smac, VEGF and Ki-67 immunoreactivity in tumor biopsies before treatment of tumor response to pre-operative CRT. Regarding Smac, patients with a favorable response to neoadjuvant CRT had higher pre-therapy levels (p=0.011). The level of Smac expression decreased after neoadjuvant therapy (p=0.044). However, VEGF expression was found to be negatively and significantly correlated with a favorable tumor response to neoadjuvant CRT (p=0.010). A transient increase in VEGF expression was detected in the resected specimens following neoadjuvant therapy (p=0.030). In addition, tumors with a low Ki-67 labeling index (Ki-67-LI) expression were found to be more sensitive to neoadjuvant therapy than those with a high expression of Ki-67-LI (p=0.034). In contrast to VEGF, the Ki-67 expression level decreased after neoadjuvant therapy. Smac, VEGF and Ki-67 expression levels, assessed immunohistochemically from pre-treatment tumor biopsies, may be useful predictive markers of rectal tumor response to pre-operative CRT.

Cytokeratin staining for complete remission in rectal cancer after chemoradiation

BACKGROUND AND AIMS

Pathologic complete remission (CR) of rectal cancer after neoadjuvant chemoradiation therapy (CRT) is generally confirmed by routine hematoxylin and eosin (H&E) staining. The aim of this study was to identify residual rectal cancer cells in primary lesions of patients with pathologic CR by immunohistochemical staining for cytokeratin.

PATIENTS AND METHODS

The medical records of 358 rectal cancer patients who underwent neoadjuvant CRT prior to radical surgery between October 2002 and August 2007 were reviewed. The authors stained sections of resected specimens of 58 patients (15.9%; 42 males; mean age 54 years) who achieved pathologic CR (as determined originally by H&E staining) with H&E and performed immunohistochemistry (IHC) using monoclonal anti-cytokeratin antibody. These stained sections were reviewed for residual rectal cancer cells by a pathologist.

RESULTS

Of the 58 patients that achieved CR by initial pathologic examinations, eight (13.8%) were found to contain tumor by cytokeratin IHC. H&E staining revealed that six of these were positive for cancer cells, but the remaining two were negative for residual rectal cancer cells.

CONCLUSION

Through better identification of residual rectal cancer cells, cytokeratin IHC offers a means of improving staging accuracy and thus provides useful information for prognosis and treatment decisions for patients with rectal cancer who had a clinical CR after CRT.

Local treatment for rectal cancer

The treatment of rectal cancer includes both radical resection and local therapy. Radical resection remains the standard treatment, but is associated with increased morbidity and mortality, as well as the potential need for a temporary and occasionally, a permanent ostomy. The benefits of local treatment include a less invasive procedure with maintenance of bowel function and avoidance of a stoma. However, the efficacy of local treatment is now being challenged as the rates of recurrence after local excision alone appear to be much higher than previously thought. Although the primary goal of an oncologic resection is disease eradication, each case must be individualized to determine an optimal care plan.

Tumor volume reduction rate measured by magnetic resonance volumetry correlated with pathologic tumor response of preoperative chemoradiotherapy for rectal cancer

PURPOSE

To determine whether the tumor volume reduction rate (TVRR) measured using three-dimensional region-of-interest magnetic resonance volumetry correlates with the pathologic tumor response after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer.

METHODS AND MATERIALS

The study included 405 patients with locally advanced rectal cancer (cT3-T4) who had undergone preoperative CRT and radical proctectomy. The tumor volume was measured using three-dimensional region-of-interest magnetic resonance volumetry before and after CRT but before surgery. We analyzed the correlation between the TVRR and the pathologic tumor response in terms of downstaging and tumor regression grade (TRG). Downstaging was defined as ypStage 0-I (ypT0-T2N0M0), and the TRG proposed by Dworak et al. was used.

RESULTS

The mean TVRR was 65.0% +/- 22.3%. Downstaging and complete regression occurred in 167 (41.2%) and 58 (14.3%) patients, respectively. The TVRRs according to ypT classification (ypT0-T2 vs. ypT3-T4), ypN classification (ypN0 vs. ypN1-N2), downstaging (ypStage 0-I vs. ypStage II-III), good regression (TRG 3-4 vs. TRG 1-2), and complete regression (TRG 4 vs. TRG 1-3) were all significantly different (p <.05). When the TVRR was categorized into three groups (<60%, 60-80%, and >80%), the rates of ypT0-T2, ypN0, downstaging, and good regression were all significantly greater for patients with a TVRR of >or=60%, as was the complete regression rate for patients with a TVRR >80% (p <.05).

CONCLUSION

The TVRR measured using three-dimensional region-of-interest magnetic resonance volumetry correlated significantly with the pathologic tumor response in terms of downstaging and TRG after preoperative CRT for locally advanced rectal cancer.

Influence of anemia on tumor response to preoperative chemoradiotherapy for locally advanced rectal cancer

PURPOSE

In rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and curative resection, we evaluated the influence of anemia on tumor response to preoperative CRT.

METHODS

Between August 2001 and July 2007, 490 patients underwent preoperative CRT, followed by curative-intent surgery. Tumor responses were evaluated based on tumor regression grade (TRG), T- and N-level downstaging, and volume reduction rates.

RESULTS

The level of pretreatment hemoglobin (Hb) was 12.9 +/- 1.7 g/dl (range, 7.2-17.6 g/dl). Tumor response rates were significantly different below and above the Hb level of 9.0 g/dl. Specifically, patients with Hb levels >or=9.0 g/dl achieved better tumor responses than those with Hb levels < 9.0 g/dl (rates of TRG 3 or 4-29.0% vs. 0%, p < 0.001). In addition, there is no differences in tumor response between the nontransfusion and transfusion groups of patients with Hb levels >or=9.0 g/dl (rates of TRG 3 or 4-29.1% vs. 23.1%, p = 0.445).

CONCLUSIONS

The serum Hb level could be a one of prognostic factors that influences the pathologic tumor response, and pretreatment anemia (below 9.0 g/dl of Hb) is associated with poor response to preoperative CRT.

Magnetic resonance imaging in locoregional staging of rectal adenocarcinoma

A comprehensive overview of the current status of magnetic resonance imaging (MRI) in the locoregional assessment and management of rectal adenocarcinoma is presented. Staging systems for rectal cancer and treatment strategies in its management are discussed to give the reader the context that shapes MRI acquisition techniques and interpretation. Findings on MRI are detailed and their accuracy reviewed based on currently available evidence. Optimization of MRI acquisition and relevant pelvic anatomy are reviewed. A detailed description of our approach in interpreting MRI for locoregional staging of rectal cancer is given and future directions are also introduced.

Rigid sigmoidoscopy and MRI are not interchangeable in determining the position of rectal cancers

PURPOSE

1) To analyse for interchangeability of rigid sigmoidoscopy and MRI in determining the distance from anus to tumour, and to determine if anterior/posterior location influences this difference. 2) To analyse the effect of preoperative chemo-radiotherapy on the distance from anus to tumour.

METHODS

Retrospective investigation of endoscopy reports and MRI series of 144 consecutive patients operated for rectal cancer.

RESULTS

The mean distance from the anal verge to the tumour measured by sigmoidoscopy was 82mm and by MRI 61mm (p<0.01). For tumours in the anterior quadrant this difference was 30mm and for tumours located in the posterior quadrant only 12mm. The distributions of the cancers as low, middle and high differ by more than 10% between the two methods. The coefficient of correlation between measurements was 0.9 but the variation was not acceptable. The length of the tumours decreased by 16mm after neoadjuvant treatment, but the distance from tumour to anus increased by only 4mm.

CONCLUSION

1) MRI and sigmoidoscopy are not interchangeable in determining the distance from anus to tumour simply by correcting for the length of the anal canal. It has not been determined if measurements from MRI or sigmoidoscopy are more accurate, but current evidence concerning the effect of neoadjuvant irradiation at different positions in the rectum is based upon rigid sigmoidoscopy. 2) The gain in tumour free distance above the anus induced by neoadjuvant treatment is small. Facilitation of sphincter-saving surgery should not be an argument for neoadjuvant treatment.

Carcinoembryonic antigen as a predictor of pathologic response and a prognostic factor in locally advanced rectal cancer patients treated with preoperative chemoradiotherapy and surgery

PURPOSE

To evaluate the role of serum carcinoembryonic antigen (CEA) as a predictor of response to preoperative chemoradiotherapy (CRT) and prognostic factor for rectal cancer.

MATERIALS AND METHODS

The study retrospectively evaluated 352 locally advanced rectal cancer patients who underwent preoperative CRT followed by surgery. Serum CEA levels were determined before CRT administration (pre-CRT CEA) and before surgery (post-CRT CEA). Correlations between pre-CRT CEA levels and rates of good response (Tumor regression grade 3/4) were explored. Patients were categorized into three CEA groups according to their pre-/post-CRT CEA levels (ng/mL) (Group A: pre-CRT CEA <or= 3; B: pre-CRT CEA >3, post-CRT CEA <or=3; C: pre- and post-CRT CEA >3 ng/mL), and their oncologic outcomes were compared.

RESULTS

Of 352 patients, good responses were achieved in 94 patients (26.7%). The rates of good response decreased significantly as the pre-CRT CEA levels became more elevated (CEA [ng/mL]: <or=3, 36.4%; 3-6, 23.6%; 6-9, 15.6%; >9, 7.8%; p < 0.001). The rates of good response were significantly higher in Group A than in Groups B and C (36.4% vs. 17.3% and 14.3%, respectively; p < 0.001). The 3-year disease-free survival rate was significantly better in Groups A and B than in Group C (82% and 79% vs. 57%, respectively; p = 0.005); the CEA grouping was identified as an independent prognostic factor (p = 0.025).

CONCLUSIONS

In locally advanced rectal cancer patients, CEA levels could be of clinical value as a predictor of response to preoperative CRT and as an independent prognostic factor after preoperative CRT and curative surgery.

Optimal surgery time after preoperative chemoradiotherapy for locally advanced rectal cancers

OBJECTIVE

To evaluate the effect of the time interval between chemoradiotherapy (CRT) and surgery on CRT response and surgical outcomes.

SUMMARY BACKGROUND DATA

Although preoperative CRT is a standard component of multimodal treatment for locally advanced rectal cancers, the optimal time for surgery after CRT has yet to be established. This study analyzed outcomes in 397 prospectively enrolled patients with locally advanced rectal cancer who underwent fractionated CRT involving 50.4 Gy radiotherapy followed by surgical resection between 4 and 8 weeks later.

METHODS

Patients were divided into 2 groups according to the time that elapsed between CRT and surgery: group A (28-41 day interval) and group B (42-56 day interval). CRT responses and surgical outcomes were analyzed.

RESULTS

Of the 397 patients, 217 (54.7%) were in group A and 180 (45.3%) in group B. The 2 groups were similar in terms of pretreatment characteristics other than a slight difference in mean age (A: 55.3 years vs. B: 57.5 years, P = 0.042). Analysis of CRT responses showed that the 2 groups were similar in terms of T-level downstaging rate (A: 47.5% vs. B: 44.4%, P = 0.548), volume reduction rate (A: 34.6% vs. B: 34.2%, P = 0.870) and complete response rate (A: 13.8% vs. B: 15.0%, P = 0.740). Analysis of surgical outcomes showed that the 2 groups were also similar in terms of sphincter-preservation rate (A: 83.9% vs. B: 82.2%, P = 0.688) and anastomosis-related complication rate (A: 5.5% vs. B: 3.9%, P = 0.453). The median follow-up period was 31 months (range, 5-63), and both groups showed similar local recurrence-free survival rates (P = 0.1165).

CONCLUSION

The present findings suggest that compared with a 4 to 6 week interval, delaying surgery for 6 to 8 weeks after completion of fractionated radiotherapy with concurrent chemotherapy does not improve CRT response or the sphincter-preservation rate, and does not decrease morbidity or local recurrence.

Analysis of anal sphincter preservation rate according to tumor level and neoadjuvant chemoradiotherapy in rectal cancer patients

The anal sphincter preservation rate (ASPR) according to tumor level and neoadjuvant chemoradiotherpy (CRT) has not been fully evaluated. Therefore, the aim of this study was to evaluate the correlation between the tumor level, neoadjuvant CRT, and the ASPR in rectal cancer patients. We studied 544 patients (tumor level, 0-6 cm) who underwent curative resection for rectal cancer between 1991 and 2005. Patients were divided six into groups according to tumor level over 1-cm intervals, and the ASPR was evaluated in patients with and without neoadjuvant CRT according to tumor level. Sphincter preservation surgery was performed in 191 patients, and 86 patents underwent neoadjuvant CRT. The overall ASPR was 43.0% (37/86) in patients with neoadjuvant CRT and 33.6% (154/458) in patients without neoadjuvant CRT (P=0.094). In an analysis according to tumor level, the ASPR was 0.0 vs 0.0% in <or=1 cm, 0.0 vs 2.1% in 1<or=2 cm (P=0.589), 11.8 vs 16.8% in 2<or=3 cm (P=0.599), 55.6 vs 20.2% in 3<or=4 cm (P=0.001), 57.7 vs 45.9% in 4<or=5 cm (P=0.227), and 66.7 vs 69.5% in 5<or=6 cm (P=0.827). Neoadjuvant CRT did not increase the ASPR in tumor level within <or=6 cm. However, for the tumor level (3<or=4 cm), neoadjuvant CRT significantly increased the ASPR.

Microarray gene expression profiling for predicting complete response to preoperative chemoradiotherapy in patients with advanced rectal cancer

PURPOSE

Preoperative chemoradiotherapy is widely used to improve local control and sphincter preservation in patients with locally advanced rectal cancer. In the present study, we investigated whether microarray gene expression analysis could predict complete response to preoperative chemoradiotherapy in rectal cancer.

METHODS

Tumor tissues were obtained from 46 patients with rectal cancer (31 for training and 15 for validation testing). All patients underwent preoperative chemoradiotherapy involving 50.4 gray radiotherapy, followed by surgical excision 6 weeks later. Response to chemoradiotherapy was evaluated according to Dworak's tumor regression grade. Tumor regression Grades 1, 2, and 3 were considered partial responses, and tumor regression Grade 4 was considered a complete response. By using the 31 training samples, genes differentially expressed between partial response and complete response were identified, and clustering analysis was performed. Prediction analysis of response to chemoradiotherapy was performed on the 31 training samples by using a selected set of 95 "predictor" genes. Those findings were validated by independent analysis of the 15 test samples.

RESULTS

The 31 training samples comprised 20 partial response and 11 complete response cases. A primary set of 261 genes was identified as differentiating between partial response and complete response. By supervised clustering using these 261 genes, 30 of 31 training samples were clustered correctly according to tumor response. A gene set comprising the top-ranked 95 genes displaying differential expression between partial response and complete response was applied to predict response to chemoradiotherapy. Complete response and partial response were accurately predicted in 84 percent (26/31) of training samples and 87 percent (13/15) of validation samples.

CONCLUSIONS

Microarray gene expression analysis was successfully used to predict complete responses to preoperative chemoradiotherapy in patients with advanced rectal cancer.

Organ preservation for rectal cancer

Organ preservation with maintenance of function in the treatment of rectal cancer is highly valued by patients. Although most patients with resectable rectal cancer can undergo a sphincter-sparing radical procedure, there are patient, tumor, surgeon, and treatment factors that influence the ability to restore intestinal continuity after radical resection. Although population-based data suggest that the rate of sphincter preservation is lower than could be obtained at expert centers, there are patients in whom low anterior resection with colo-anal anastomosis is not technically feasible and/or oncologically sound. Additionally, resection with ultralow anastomosis results in functional compromise in many patients. Local treatment of rectal cancer aims to decrease the morbidity and the functional sequelae associated with radical resection; however, local excision is associated with a higher rate of local recurrence than is radical resection. Strict selection criteria are essential when considering local excision, and patients should be informed of the risk of local recurrence. The use of adjuvant therapy with local excision, particularly in patients with T2 lesions, has promise but should be considered only as part of a clinical trial.

Comparison of 5-fluorouracil/leucovorin and capecitabine in preoperative chemoradiotherapy for locally advanced rectal cancer

PURPOSE

To describe our experience with a bolus injection of 5-fluorouracil and leucovorin (FL) vs. capecitabine in terms of radiologic and pathologic findings in preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer.

METHODS

The study enrolled 278 patients scheduled for preoperative CRT using two protocols with different chemotherapeutic regimens. Pelvic radiotherapy (50.4 Gy) was delivered concurrently with FL (n = 145) or capecitabine (n = 133). Surgery was performed 6 weeks after CRT completion. Tumor responses to CRT were measured using both radiologic and pathologic examination. Magnetic resonance volumetry was performed at the initial workup and just before surgery after completion of preoperative CRT. Post-CRT pathology tests were used to determine tumor stage and regression.

RESULTS

Radiologic examination showed that tumor volume decreased by 68.2% +/- 20.5% in the FL group and 68.3% +/- 22.3% in the capecitabine group (p = 0.970). Postoperative pathologic T stage determination showed that downstaging occurred in 44.3% of FL and 49.9% of capecitabine patients (p = 0.571). The tumor regression grades after CRT were Grade 1 (minimal response) in 22.6% and 21.0%, Grade 2 (moderate response) in 53.2% and 50.0%, Grade 3 (near-complete response) in 12.9% and 12.9%, and Grade 4 (complete response) in 11.3% and 16.1% of the FL and capecitabine groups, respectively (p = 0.758).

CONCLUSION

In the present study, the radiologic and pathologic findings did not reveal significant differences in short-term tumor responses between preoperative FL and capecitabine CRT for locally advanced rectal cancer. Long-term results and a prospective randomized trial are needed.

Impact des traitements préopératoires (radiothérapie et chimiothérapie) dans la conservation sphinctérienne des cancers du très bas rectum

Sphincter preservation for low rectal carcinoma must be evaluated with a plurifactoriel approach. Multicentric randomised studies are unable to demonstrate a relationship between complete tumoral response and conservative sphincteric rate. Intersphincteric resection technique is becoming a main factor to transform conservative indication. Complete tumoral response should not be the only purpose of future trials.