Is final TNM staging a predictor for survival in locally advanced rectal cancer after preoperative chemoradiation therapy?

Prognostic analysis of rectal cancer patients after neoadjuvant chemoradiotherapy: different prognostic factors in patients with different TRGs

PURPOSE

The extent of tumor regression varies widely among locally advanced rectal cancer (LARC) patients who receive neoadjuvant chemoradiotherapy (NCRT) followed by total mesorectal excision (TME). The purpose of this retrospectively study is to assess prognostic factors in LARC patients with NCRT, and further to analyze survival outcomes in patients with different tumor regression grades (TRGs).

METHODS

This study includes LARC patients who underwent NCRT and TME at our institution. We retrospectively analyzed the clinicopathological characteristics and survival of all patients, and performed subgroup analysis for patients with different TRGs. Survival differences were compared using the Kaplan-Meier method and the log rank test. Additionally, a multiple Cox proportional hazard model was used to identify independent prognostic factors.

RESULTS

The study included 393 patients, with 21.1%, 26.5%, 45.5%, and 6.9% achieving TRG 0, TRG 1, TRG 2, and TRG 3, respectively. The overall survival (OS) rate and disease-free survival (DFS) rate for all patients were 89.4% and 70.7%, respectively. Patients who achieved TRG 0-3 had different 5-year OS rates (96.9%, 91.1%, 85.2%, and 68.8%, P = 0.001) and 5-year DFS rates (80.8%, 72.4%, 67.0%, 55.8%, P = 0.031), respectively. Multivariate analyses showed that the neoadjuvant rectal (NAR) score was an independent prognostic indicator for both overall survival (OS) (HR = 4.040, 95% CI = 1.792-9.111, P = 0.001) and disease-free survival (DFS) (HR = 1.971, 95% CI = 1.478-2.628, P ˂ 0.001). In the subgroup analyses, the NAR score was found to be associated with DFS in patients with TRG 1 and TRG 2. After conducting multivariate analysis, it was found that ypT stage was a significant predictor of DFS for TRG 1 patients (HR = 4.384, 95% CI = 1.721-11.168, P = 0.002). On the other hand, ypN stage was identified as the dominant prognostic indicator of DFS for TRG 2 patients (HR = 2.795, 95% CI = 1.535-5.091, P = 0.001). However, none of these characteristics was found to be correlated with survival in patients with TRG 0 or TRG 3.

CONCLUSION

NAR score, in particular, appears to be the most powerful prognostic factor. It is important to consider various prognostic predictors for patients with different TRGs.

Predicting survival in locally advanced rectal cancer with effective chemoradiotherapy response

BACKGROUND

Locally advanced rectal cancer patients often display favorable responses and favorable oncologic outcomes. Due to the low recurrence rate, there is scarcity of studies investigating the prognostic factors influencing their survival. Therefore, our study sought to assess the prognostic factors associated with survival in rectal cancer patients who achieved either a pathologic complete response or a pathologic stage I after neoadjuvant chemoradiotherapy combined with radical resection.

METHODS

In this retrospective study, we analyzed data from cohort of 1394 patients diagnosed with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy combined with total mesorectal excision from January 2008 to April 2017. Finally, we selected 474 (34.2 %) who exhibited either a pathologic complete response or attained pathologic stage I following the treatment. Subsequently, we analyzed the prognostic factors influencing disease-free and overall survival.

RESULTS

A total of 161 (34 %) achieved a pathologic complete response. Our analysis revealed that circumferential resection margin and the administration of adjuvant chemotherapy were prognostic factors for disease-free survival (p = 0.011, p = 0.022). Furthermore, factors influencing overall survival included the clinical N stage and administration of adjuvant chemotherapy (p = 0.035, p = 0.015).

CONCLUSION

In conclusion, the circumferential resection margin, clinical N stage, and administration of adjuvant chemotherapy were prognostic factors for survival in patients showing good response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer. For patients with a positive circumferential resection margin and clinical N (+) stage, intensive follow-up might be needed to achieve favorable oncologic outcomes. Also, we recommend considering adjuvant chemotherapy as a beneficial treatment approach for these patients.

Late Local Recurrence after Neoadjuvant Therapy and Radical Resection for Locally Advanced Rectal Cancer

Neoadjuvant radiochemotherapy (RCT) and lately total neoadjuvant therapy (TNT) improved local recurrence rates of rectal cancer significantly compared to total mesorectal excision (TME) alone. Yet the occurrence and impact of late local recurrences after many years appears to be a distinct biological problem. We included n = 188 patients with rectal cancer after RCT and radical resection in this study; n = 38 of which had recurrent disease (sites: local (8.0%), liver (6.4%), lung (3.7%)). We found that 68% of all recurrences developed within the first two years. Four patients, however, experience recurrence >8 years after surgery. Here, we report and characterize four cases of late local recurrence (10% of patients with recurrent disease), suggesting that neoadjuvant therapy in principle delays local recurrence.

Downstaging after preoperative chemoradiation for locally advanced rectal cancer is associated with better survival than pathologic stage 0-1 disease treated with upfront surgery

BACKGROUND AND OBJECTIVES

It is unknown how patients with locally advanced rectal cancer with significant response to preoperative radiotherapy/chemoradiotherapy fare relative to patients with true pathologic 0-1 disease undergoing upfront surgery. We aimed to determine whether survival is improved in locally advanced rectal cancer downstaged to pathologic stage 0-1 disease compared to true pathologic stage 0-1 tumors.

METHODS

A retrospective review of the National Cancer Database between 2004 and 2016 was conducted. Three groups were identified: (1) clinical stage 2-3 disease downstaged to pathologic stage 0-1 disease after radiotherapy, (2) clinical stage 2-3 disease not downstaged after radiotherapy, and (3) true pathologic 0-1 tumors undergoing upfront surgery. The primary endpoint was overall survival and was compared using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

The study population consisted of 59,884 patients. Of the 40,130 patients with locally advanced rectal cancer treated with preoperative radiation, 12,670 (31.5%) had significant downstaging (group 1), while 27,460 (68.4%) had no significant downstaging (group 2). A total of 19,754 had pathologic 0-1 disease treated with upfront resection (group 3). On Kaplan-Meier analysis, downstaged patients had significantly better overall survival compared to both non-downstaged and true pathologic stage 0-1 patients (median 156 vs. 99 and 136 months, respectively, p < 0.001). On multivariate analysis, downstaged patients had significantly better survival (HR 0.88, p < 0.001) compared to true pathologic 0-1 patients.

CONCLUSIONS

Locally advanced rectal cancer downstaged after preoperative radiotherapy has significantly better survival compared to true pathologic stage 0-1 disease treated with upfront surgery. Response to chemoradiotherapy likely identifies a subset of patients with a particularly good prognosis.

Does neoadjuvant rectal score predict treatment outcomes better than the all grading systems used in neoadjuvantly treated rectal cancer?

BACKGROUND

/Objective: To compare the prognostic value of the yield pathologic (yp) stage, used 4 tumor regression grading (TRG) systems, and neoadjuvant rectal score(NARS) in patients with locally advanced rectal cancer (LARC) who received long-term neoadjuvant chemoradiotherapy (nCRT).

METHODS

Between 2005 and 2017, we included 302 patients with LARC who treated with nCRT. Postoperative pathological responses were graded by using Dworak, American Joint Committee on Cancer, Mandart, Memorial Sloan Kettering Cancer Center, grading systems and NARS([5ypN-3(kT-pT)+12]2/9,61) calculations. Their results were compared in terms of treatment outcomes.

RESULTS

The median follow-up time was 51 months (range 5-136). There was a significant relation between cT stage and the response in used grading systems(p < 0,001). Median overall(OS), local recurrence free(LRFS), and distant metastasis free(MFS) survival rates were 50, 48, and 45 months, respectively. 5-year OS, LRFS, and MFS rates were 71%, 92%, and 72%, respectively. According to the NARS and treatment response grating systems, a significant difference was found between the low risk and high risk groups in terms of OS, LRFS, and MFS rates. While it was not seen any difference in terms of OS and MFS, NARS was found to predict LRFS better than other grading systems. In multivariate analysis, high NARS was found to be correlated with worse OS and worse MFS. On the other hand, pCR was the another important factor affecting treatment outcomes.

CONCLUSIONS

While used systems except NARS group patients according to ypT status in surgical tissue, NARS add the value of ypN status in addition to ypT status. It could be suggested to use NARS to predict LRFS.

Post-Chemoradiation Metastatic, Persistent and Resistant Nodes in Locally Advanced Rectal Cancer: Metrics and Their Impact on Long-Term Outcome

BACKGROUND

The purpose of this study was to evaluate the long-term oncological progression pattern of locally advanced rectal cancer patients with post-neoadjuvant nodal metastatic disease (ypN+) and correlate potential prognostic features associated with proven radiochemoresistant nodal biology.

METHODS

Individual patient data (100 variables) from a 20-year consecutive single-institution multidisciplinary experience (1995-2015), delivering multimodal therapy to rectal cancer patient candidates for radical treatment, including a neoadjuvant component and surgical resection with or without intraoperative radiotherapy followed by optional adjuvant chemotherapy. The ypN+ disease data was registered in the context of initial staging categories post-neoadjuvant T status (ypT).

RESULTS

Data on 487 patients showed histologically confirmed diagnoses of metastatic nodal disease in 108 specimens (ypN+, 22.1). There was a significant age difference (p = 0.009) between the ypN groups: age ≥ 65 was 57.6% in pN0 and 43.5% in ypN+ and patients aged < 65 constituted 42.4% of pN0 and 56.5% of ypN+. According to the clinical stage there were statistically significant differences (p = 0.001) in the categories' distribution: ypN+ patients 10.8% were stage II and 89.2% were stage III. Univariant analysis on outcome variables showed statistically significant differences in overall survival at 7 years (63.8% vs. 55.7%, p = 0.016) disease-free survival (DFS) (78% vs. 53.8%, p = 0.000) and local recurrence-free survival (LRFS) (93.6% vs. 84%, p = 0.002).

CONCLUSIONS

The presence of nodal metastases (ypN+) after neoadjuvant therapy containing long-course pelvic irradiation severely impacts the long-term outcome for patients with locally advanced rectal cancer and correlates with multiple clinical and therapeutic variable metrics. Implementation of local and systemic therapies should be adapted and intensified in relation to the finding of ypN+ category in surgical specimens.

A good preoperative immune prognostic index is precits a better prognosis for locally advanced rectal cancer patients with ypTNM stage II who underwent radical resection after neoadjuvant chemoradiotherapy

BACKGROUND

No studies have investigated the role of IPI in assessing the prognosis of locally advanced rectal cancer (LARC) patients undergoing nCRT.

OBJECTIVE

We attempted to combine neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (sLDH) to generate a new rectal immune prognostic index (RIPI) to explore whether RIPI is associated with LARC prognosis. We aimed to identify whether there is a population that might benefit from RIPI in LARC.

METHODS

LARC patients who underwent radical surgery after Neoadjuvant chemoradiotherapy (nCRT) were enrolled between February 2012 and May 2017. Based on the best cut-off points of NLR and sLDH, we developed RIPI. The patients were grouped as follows: (1) good, RIPI = 0, good, 0 factors; (2) poor, RIPI = 1, 1 or 2 factors.

RESULTS

This study enrolled 642 patients. In yp TNM stage II patients, 5-year disease-free survival (DFS) differed significantly between the RIPI = 1 and RIPI = 0 groups (p = 0.03). Five-year DFS did not differ significantly between IPI = 0 and IPI = 1 groups in ypCR, stage I, stage II, and stage III. In multivariate analysis, the significant factor predicting DFS was pre-nCRT RIPI score (p = 0.035).

CONCLUSION

The pre-nCRT RIPI was closely related to the prognosis of LARC patients undergoing nCRT. Particularly, RIPI is significant in evaluating the prognosis of ypTNM stage II LARC patients who underwent radical resection after nCRT.

External validation and comparison of MR-based radiomics models for predicting pathological complete response in locally advanced rectal cancer: a two-centre, multi-vendor study

OBJECTIVES

The aim of this study was two-fold: (1) to develop and externally validate a multiparameter MR-based machine learning model to predict the pathological complete response (pCR) in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT), and (2) to compare different classifiers' discriminative performance for pCR prediction.

METHODS

This retrospective study includes 151 LARC patients divided into internal (centre A, n = 100) and external validation set (centre B, n = 51). The clinical and MR radiomics features were derived to construct clinical, radiomics, and clinical-radiomics model. Random forest (RF), support vector machine (SVM), logistic regression (LR), K-nearest neighbor (KNN), naive Bayes (NB), and extreme gradient boosting (XGBoost) were used as classifiers. The predictive performance was assessed using the receiver operating characteristic (ROC) curve.

RESULTS

Eleven radiomics and four clinical features were chosen as pCR-related signatures. In the radiomics model, the RF algorithm achieved 74.0% accuracy (an AUC of 0.863) and 84.4% (an AUC of 0.829) in the internal and external validation sets. In the clinical-radiomics model, RF algorithm exhibited high and stable predictive performance in the internal and external validation datasets with an AUC of 0.906 (87.3% sensitivity, 73.7% specificity, 76.0% accuracy) and 0.872 (77.3% sensitivity, 88.2% specificity, 86.3% accuracy), respectively. RF showed a better predictive performance than the other classifiers in the external validation datasets of three models.

CONCLUSIONS

The multiparametric clinical-radiomics model combined with RF algorithm is optimal for predicting pCR in the internal and external sets, and might help improve clinical stratifying management of LARC patients.

KEY POINTS

• A two-centre study showed that radiomics analysis of pre- and post-nCRT multiparameter MR images could predict pCR in patients with LARC. • The combined model was superior to the clinical and radiomics model in predicting pCR in locally advanced rectal cancer. • The RF classifier performed best in the current study.

Surveillance strategies following curative resection and non-operative approach of rectal cancer: How and how long? Review of current recommendations

Different follow-up strategies are available for patients with rectal cancer following curative treatment. A combination of biochemical testing and imaging investigation, associated with physical examination are commonly used. However, there is currently no consensus about the types of tests to perform, the timing of the testing, and even the need for follow-up at all has been questioned. The aim of this study was to review the evidence of the impact of different follow-up tests and programs in patients with non-metastatic disease after definitive treatment of the primary. A literature review was performed of studies published on MEDLINE, EMBASE, the Cochrane Library and Web of Science up to November 2022. Current published guidelines from the most authoritative specialty societies were also reviewed. According to the follow-up strategies available, the office visit is not efficient but represents the only way to maintain direct contact with the patient and is recommended by all authoritative specialty societies. In colorectal cancer surveillance, carcinoembryonic antigen represents the only established tumor marker. Abdominal and chest computed tomography scan is recommended considering that the liver and lungs are the most common sites of recurrence. Since local relapse in rectal cancer is higher than in colon cancer, endoscopic surveillance is mandatory. Different follow-up regimens have been published but randomized comparisons and meta-analyses do not allow to determine whether intensive or less intensive follow-up had any significant influence on survival and recurrence detection rate. The available data do not allow the drawing of final conclusions on the ideal surveillance methods and the frequency with which they should be applied. It is very useful and urgent for clinicians to identify a cost-effective strategy that allows early identification of recurrence with a special focus for high-risk patients and patients undergoing a “watch and wait” approach.

Applying a neoscore in locally advanced rectal cancer is beneficial in predicting local recurrences after surgery

BACKGROUND AND AIM

The current study was undertaken to provide more detailed prognostic models for early prediction of local recurrences and local recurrence free survival (RFS) using different radiologic and pathologic features of locally advanced rectal carcinomas treated with neoadjuvant chemoradiation (CRT).

METHODS

One hundred patients with locally advanced rectal carcinomas decided to receive neoadjuvant CRT were retrospectively recruited, Hazard ratios (HR) were determined in the two cox regression models and only significant ratios were considered for pointing, Models were built to determine their important effects of different predictors including: pathologic T (T), pathologic N (N), grade (G), clinical stage (cTNM), site (S), perineural invasion (PNI), and response to CRT (R) on 3-year RFS, goodness of performance of each model was measured by Harrell's C index.

RESULTS

HR of 1st group of models: T+N, T+N+G, T+N+G+S, T+N+G+S+PNI, and T+N+G+S+PNI+R were summated and categorized into scores, these scores were significantly correlated with the risk of recurrence (Somer's D = 0.5, p<0.0001) & Harrell's C index = 0.751, (Somer's D = 0.6, p<0.0001) & its Harrell's C index = 0.794, (Somer's D = 0.7, p<0.0001) & C index = 0.826, Somer's D = 0.7, p<0.0001) & C index = 0.827, and (Somer's D = 0.7, p<0.0001) & C index = 0.843 respectively. The 2nd group of models including: cTNM stage, cTNM+G, cTNM+G+S, cTNM+G+S+PNI, cTNM+G+S+PNI+R scores which were significantly correlated with the HR of LRR (Somer's D = 0.2, 0.5, 0.6, 0.6, & 0.6 respectively), (p = 0.006, <0.0001, <0.0001, <0.0001, <0.0001 respectively), the corresponding Harrell's C indices were 0.595, 0.743, 0.782, 0.795, & 0.813 respectively.

CONCLUSION

We propose that the addition of biologic factors to staging of rectal cancer provide precise stratification and association with local recurrences in patients received preoperative CRT.

Effect of interval between neoadjuvant chemoradiotherapy and surgery on disease recurrence and survival in rectal cancer: long-term results of a randomized clinical trial

BACKGROUND

The optimal timing of surgery following chemoradiotherapy (CRT) is controversial. This trial aimed to assess disease recurrence and survival rates between patients with locally advanced rectal adenocarcinoma (LARC) who underwent total mesorectal excision (TME) after a waiting interval of 8 weeks or less (classic interval; CI) versus more than 8 weeks (long interval; LI) following preoperative CRT.

METHODS

This was a phase III, single-centre, randomized clinical trial. Patients with LARC situated within 12 cm of the anal verge (T3-T4 or N+ disease) were randomized to undergo TME within or after 8 weeks after CRT.

RESULTS

Between January 2006 and January 2017, 350 patients were randomized, 175 to each group. As of February 2022, the median follow-up time was 80 (6-174) months. Among the 322 included patients (CI, 159; LI, 163) the cumulative incidence of locoregional recurrence at 5 years was 10.1 per cent in the CI group and 6.9 per cent in the LI group (P = 0.143). The cumulative incidence of distant metastasis at 5 years was 30.8 per cent in the CI group and 18.6 per cent in the LI group (sub-HR = 1.78; 95 per cent c.i. 1.14 to 2.78, P = 0.010). The disease-free survival (DFS) in each group was 59.7 and 69.9 per cent respectively (P = 0.157), and overall survival (OS) rates at 5 years were 73.6 versus 77.9 per cent (P = 0.476).

CONCLUSION

Incidence of distant metastasis decreased with an interval between CRT and surgery exceeding 8 weeks, but this did not impact on DFS or OS.

REGISTRATION NUMBER

NCT03287843 (http://www.clinicaltrials.gov).

Development and external validation of prognostic nomograms for liver disease-free and overall survival in locally advanced rectal cancer with neoadjuvant therapy: a post cohort study based on the FOWARC trial

Background

There is still a lack of nomograms that can accurately predict liver metastasis and poor prognosis after neoadjuvant therapy for locally advanced rectal cancer (LARC). Effective nomograms may help clinicians better identify LARC patients with potential high-risk risks, so as to carry out more targeted monitoring, treatment and follow-up.

Methods

The nomograms were based on the FOWARC trial (NCT01211210), which included 302 LARC patients who underwent neoadjuvant treatment before surgery at the Sixth Affiliated Hospital of Sun Yat-sen University from 2011 to 2014. The predictive accuracy and discriminative ability of the nomograms were determined by the concordance index (C-index) and calibration curve. The results were validated using bootstrap resampling and a prospective study on 100 patients in 2017.

Results

The 3-year liver disease-free survival (LDFS) rate after neoadjuvant treatment for LARC was 91.65% (training cohort 92.22%, validation cohort 90.01%). Factors associated with LDFS were hepatitis B virus (HBV) infection, anemia, lymph node number, postoperative T stage and tumor nodule, which were all included in the nomogram for LDFS. The C-indies of the nomogram for LDFS were 0.828 and 0.845 in the training and validation cohorts. The 3-year overall survival (OS) rate was 94.14% (training cohort 94.13%, validation cohort 94.05%). Factors in the nomogram for OS were mesorectal fascia involvement (MRF), postoperative N stage, pathological differentiation, tumor nodule and neural invasion. The C-indies of the nomogram for predicting OS were 0.73 and 0.774 in the training and validation cohorts. The calibration curve for the survival probability showed good agreement between the nomogram predictions and the actual observations.

Conclusions

The nomograms established in this study can effectively predict LDFS and has good clinical application potential for OS in LARC patients treated with neoadjuvant therapy.

A practical framework for the targeted use of total neoadjuvant therapy for rectal cancer

Total neoadjuvant therapy (TNT) for rectal cancer is the preoperative delivery of radiation or chemoradiotherapy as well as systemic chemotherapy for the purpose of improving treatment completion rates and decreasing toxicity, maximizing the primary tumor response, and improving survival for patients with rectal cancer. This review summarizes the data surrounding TNT, including several recent randomized controlled trials. Moreover, it reviews the literature regarding high-quality surgery and the role of radiation and chemotherapy in the treatment of rectal cancer in the modern era. Finally, it presents an evidence-based protocol for the selective use of TNT in the treatment of patients with rectal cancer.

Small heterodimer partner as a predictor of neoadjuvant radiochemotherapy response and survival in patients with rectal cancer: A preliminary study

Small heterodimer partner (SHP) plays an essential role in the regulation of innate immune and inflammatory responses. The aim of the present study was to identify whether SHP levels are associated with cancer immunology and treatment outcomes in rectal cancer. SHP expression was analyzed via gene set enrichment analysis and the OncoLnc database. In addition, immunohistochemistry and reverse transcription-quantitative PCR analyses were performed on the tissues of patients with locally advanced rectal cancer, and the associations of SHP expression with the clinicopathological and hematological features or treatment response to preoperative radiochemotherapy (pRCT) were analyzed retrospectively. Furthermore, the present study investigated whether SHP expression correlated with immune infiltration levels and immune checkpoint molecules in rectal cancer. The results revealed that low SHP mRNA expression was significantly associated with an inflammatory response and poor prognosis. The nuclear expression of SHP was associated with clinical N stage, neutrophil count, lymphocyte count, neutrophil-lymphocyte ratio and complete pathologic response following pRCT. The low nuclear expression of SHP was associated with poor overall and distant metastasis-free survival (DMFS). In multivariate analysis, the low nuclear expression of SHP was identified as a significant independent prognostic factor for DMFS and a marginally significant prognostic factor for overall survival in rectal cancer. Furthermore, patients with low SHP expression exhibited higher neutrophil and CD8⁺ T cell infiltration levels and higher PD-L1 expression in rectal adenocarcinoma. These results indicate that SHP may act as an anti-inflammatory mediator via the regulation of systemic and local immune responses in rectal cancer. Moreover, SHP might be useful a potential marker or therapeutic target in rectal cancer.

Neoadjuvant Capecitabine and Oxaliplatin Before Concurrent Capecitabine and Radiation in Locally Advanced Rectal Cancers: Experience of a Cancer Hospital in Pakistan

To report the toxicity and pathologic response rates after adding neoadjuvant capecitabine and oxaliplatin (CAPOX) followed by concurrent radiation and capecitabine (CAPRT) and surgery in patients with locally advanced rectal cancer.

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy

BACKGROUND

The purpose of this study was to investigate the prevalence of ypN+ status according to ypT category in patients with locally advanced rectal cancer treated with chemoradiotherapy and total mesorectal excision, and to assess the impact of ypN+ on disease recurrence and survival by pooled analysis of individual-patient data.

METHODS

Individual-patient data from 10 studies of chemoradiotherapy for rectal cancer were included. Pooled rates of ypN+ disease were calculated with 95 per cent confidence interval for each ypT category. Kaplan-Meier and Cox regression analyses were undertaken to assess influence of ypN status on 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

Data on 1898 patients were included in the study. Median follow-up was 50 (range 0-219) months. The pooled rate of ypN+ disease was 7 per cent for ypT0, 12 per cent for ypT1, 17 per cent for ypT2, 40 per cent for ypT3, and 46 per cent for ypT4 tumours. Patients with ypN+ disease had lower 5-year DFS and OS (46.2 and 63.4 per cent respectively) than patients with ypN0 tumours (74.5 and 83.2 per cent) (P < 0.001). Cox regression analyses showed ypN+ status to be an independent predictor of recurrence and death.

CONCLUSION

Risk of nodal metastases (ypN+) after chemoradiotherapy increases with advancing ypT category and needs to be considered if an organ-preserving strategy is contemplated.

Usefulness of Endoscopic Tattooing Before Neoadjuvant Therapy in Patients with Clinical Complete Response in Locally Advanced Rectal Cancer for Providing a Safe Distal Surgical Margin

Background: Endoscopic tattooing of colorectal tumors enables tumor localization and determination of appropriate surgical margins. It becomes very difficult to detect the distal surgical margins (DSMs) of rectal tumors in patients who obtain clinical complete response (cCR) after neoadjuvant therapy. In this study, our aim is to examine the benefits of endoscopic tattooing of the tumor before neoadjuvant therapy in patients with locally advanced rectal cancer in accurate localization of the previous tumor and in providing appropriate DSMs in cases with cCR. Patients and Methods: The patients who were diagnosed with locally advanced rectal cancer, received neoadjuvant therapy and subsequently achieved cCR, and underwent surgery between January 2015 and October 2020 were included in the study. The patients were divided into two groups according to whether they were endoscopically tattooed before neoadjuvant chemoradiotherapy. Results: A total of 49 cases were included in the study. Significantly better DSMs were observed especially in female gender in the tattooed group. DSMs were found to be closer to the resection margins in the nontattooed group. It was found that endoscopic tattooing had a significant effect on the DSM in the regression analysis (P = .06, R² = 0.47). It was determined that laparoscopy or open surgery alone did not differ in terms of DSMs but open surgery together with tattooing was found to be strongly effective in providing larger DSMs. Conclusion: In locally advanced rectal cancer, endoscopic tattooing of the distal margin of the tumor before neoadjuvant therapy is a reliable and effective method for obtaining a safe DSM and not leaving the residual tumor at the lower end of anastomosis, especially in cases of cCR.

Prognostic Impact of the Neoadjuvant Rectal Score as Compared With the Tumor Regression Grade and Yield Pathologic TNM Stage in Patients With Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

The present study compared the prognostic value of the yield pathologic (yp) stage, tumor regression grade (TRG), and neoadjuvant rectal (NAR) score in patients with locally advanced rectal cancer (LARC) who received neoadjuvant chemoradiotherapy (nCRT).

PATIENTS AND METHODS

For the assessment of tumor regression, the Dworak grading system was used. The NAR score was calculated using the following equation: (5ypN-3[cT-ypT]+12)²÷9.61.

RESULTS

In univariate analysis, the NAR score and ypTNM stage were significantly associated with DFS [hazard ratio (HR)=2.514, p<0.001 and HR=3.200, p<0.001] and OS (HR=2.292, p=0.001 and HR=2.859, p<0.001), whereas the TRG was significantly associated with only DFS (HR=2.008, p=0.017). In multivariate analysis, the ypTNM stage was the only independent prognostic factor for DFS (HR=3.796, p<0.001) and OS (HR=3.591, p=0.0034).

CONCLUSION

Only the ypTNM stage was significantly associated with survival outcomes in multivariate analysis, suggesting that it is the most powerful prognostic factor of nCRT in patients with LARC.

Oncological Outcomes of Pathological T1 Lower Rectal Cancer Patients With or Without Preoperative Chemoradiotherapy

BACKGROUND/AIM

It remains unclear whether rectal cancers down-staged by preoperative chemoradiotherapy (CRT) have similar prognoses to those of the same stage without preoperative CRT. We compared prognoses of pT1 rectal cancer patients stratified by preoperative CRT.

PATIENTS AND METHODS

We retrieved data of patients with pathological T1 rectal cancer between 2003 and 2020. Patients were divided into the "ypT1 group" who received preoperative CRT following surgery and the "pT1 group" who underwent surgery alone. Factors associated with relapse-free survival (RFS) were investigated.

RESULTS

Among 86 patients, ypT1 and pT1 groups comprised 18 and 68 patients, respectively. There was no significant difference in RFS between the groups (p=0.19). Tumor location within 5 cm from the anal verge was associated with recurrence (hazard ratio: 0.13, p=0.034).

CONCLUSION

The prognosis of patients with ypT1 rectal cancer was similar to that of patients with pT1. Low tumor location was a poor prognostic factor.

Prognosis Comparisons of Laparoscopy versus Open Surgery for Rectal Cancer Patients after Preoperative Chemoradiotherapy: A Meta-Analysis

AIM

We aimed to compare the oncological outcomes of laparoscopy and open resection for patients with rectal cancer following neoadjuvant chemoradiotherapy (NCRT).

METHODS

We searched the publications that compared the efficacy of laparoscopic surgery and open thoracotomy in treatment outcomes of rectal cancer after NCRT. All trials analyzed the summary hazard ratios of the endpoints of interest, including survival and individual postoperative complications.

RESULTS

Totally, 10 trials met our inclusion criteria. The pooled analysis of 3-year disease-free survival (OR 1.39, 95% CI 0.93-2.06; p = 0.11) and 3-year overall survival (OR 1.01, 95% CI 0.70-1.45; p = 0.97) showed that laparoscopic surgery did not achieve beneficial effects compared with open thoracotomy. The pooled result of duration of surgery indicated that laparoscopic surgery was associated with a trend for longer surgery time (SMD 27.53, 95% CI 1.34-53.72; p = 0.04), shorter hospital stay (SMD -1.64, 95% CI -2.70 to -0.58; p = 0.002), more postoperative complications (OR 0.77, 95% CI 0.60-0.99; p = 0.04), and decreased blood loss (SMD -49.87, 95% CI -80.61 to -19.14; p = 0.001). However, the number of removed lymph nodes, positive circumferential resection margin, as well as complications after surgery showed significant differences between the 2 groups.

CONCLUSIONS

We focused on current evidence and reviewed the studies indicating that similar oncological outcomes were associated with laparoscopic surgery following NCRT for patients with locally advanced lower rectal cancer in comparison with open surgery.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study

PURPOSE

Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer.

METHODS

Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes.

RESULTS

One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033).

CONCLUSION

Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Ten-year survival after pathologic complete response in rectal adenocarcinoma

BACKGROUND

Multimodal treatment is the standard of care for rectal adenocarcinoma, with a subset of patients achieving a pathologic complete response (pCR). While pCR is associated with improved overall survival (OS), long-term data on patients with pCR is limited.

METHODS

This is a single institution retrospective cohort study of all patients with clinical stages II/III rectal adenocarcinoma who underwent neoadjuvant chemoradiation therapy and operative resection (January 1, 2004-December 31, 2017). PCR was defined as no tumor identified in the rectum or associated lymph nodes by final pathology.

RESULTS

Of 370 patients in this cohort, 50 had a pCR (13.5%). For pCR patients, 5-year disease-free survival (DFS) was 92%, 5-year OS was 95%. Twenty-six patients had surgery > 10 years before the study end date, of which 20 had an OS > 10 years (77%) with median OS 12.1 years and 95% alive to date (19/20). Of the 50 pCR patients, there was a single recurrence in the lung at 44.3 months after proctectomy which was surgically resected.

CONCLUSION

For patients with rectal adenocarcinoma that undergo neoadjuvant chemoradiation and surgical resection, pCR is associated with excellent long-term DFS and OS. Many patients live greater than 10 years with no evidence of disease recurrence.

Oncologic effects of adjuvant chemotherapy in patients with ypT0-2N0 rectal cancer after neoadjuvant chemoradiotherapy and curative surgery: a meta-analysis

Purpose

The role of adjuvant chemotherapy for patients with ypT0–2N0 rectal cancer following neoadjuvant chemoradiotherapy (nCRT) and curative surgery is uncertain. We performed a meta-analysis using selected studies to compare adjuvant chemotherapy with observation for this cohort of patients.

Methods

PubMed, Embase, and the Cochrane Library were searched. Data were pooled, and overall effect size was calculated using random effect models. Outcome measures were 5-year overall survival (OS), disease-free survival (DFS), local, and distant recurrence.

Results

We included 17 nonrandomized studies for qualitative analysis and 16 nonrandomized studies that examined 4,747 patients for the meta-analysis. In analysis of patients with ypT0N0 rectal cancer, adjuvant chemotherapy had no significant effect on OS (odds ratio [OR], 1.53; 95% confidence interval [CI], 0.86–2.72; I² = 27%), DFS (OR, 1.22; 95% CI, 0.61–2.42; I² = 5%), local recurrence (OR, 0.78; 95% CI, 0.08–7.37; I² = 0%), and distant recurrence (OR, 1.04; 95% CI, 0.41–2.62; I² = 0%). In analysis of patients with ypT1–2N0 rectal cancer, adjuvant chemotherapy also had no significant effect on OS (OR, 2.15; 95% CI, 0.59–7.80; I² = 26%), DFS (OR, 1.66; 95% CI, 0.35–7.85; I² = 44%), local recurrence (OR, 2.56; 95% CI, 0.72–9.13; I² = 0%), and distant recurrence (OR, 1.15; 95% CI, 0.23–5.87; I² = 0%).

Conclusion

Adjuvant chemotherapy may have no oncologic benefits in patients with ypT0–2N0 rectal cancer after nCRT and radical surgery. Routine use of adjuvant chemotherapy for those patients may be avoided.

Histology of Colorectal Carcinoma: Proven and Purported Prognostic Factors

Although tumor stage has a profound influence on prognosis, several histologic features are also important. These parameters predict biological behavior and can be used by clinicians to determine whether patients are at high risk for disease progression and, thus, are candidates for adjuvant therapy, particularly when they have localized (ie, stage II) disease. This article summarizes the evidence supporting the prognostic values of various histologic parameters evaluated by pathologists who assign pathologic stage to colorectal cancers. Criteria to be discussed include histologic subtype, tumor grade, lymphatic and perineural invasion, tumor budding, and host immune responses.

Predicting prognosis according to preoperative chemotherapy response in patients with locally advanced lower rectal cancer

BACKGROUND

Neoadjuvant chemoradiotherapy is regarded as the standard of treatment for locally advanced lower rectal cancer, although some of these cases are systemic, and distant control may be inadequate. Neoadjuvant chemotherapy could compensate for such shortcomings, potentially yielding better survival outcomes. We aimed to stratify patients into prognostic groups on the basis of preoperative factors, including response to neoadjuvant chemotherapy.

METHODS

We retrospectively analyzed patients with locally advanced lower rectal adenocarcinoma (clinical stage II/III with high-risk features of distant metastasis) who were treated with neoadjuvant chemotherapy (without radiotherapy) followed by curative resection between 2010 and 2017. Reduction in tumor volume (before vs. after neoadjuvant chemotherapy) was measured using magnetic resonance imaging, and a reduction above 60% was defined as a good response. Recurrence and overall survival were evaluated.

RESULTS

The cohort comprised 102 patients. Good response to neoadjuvant chemotherapy was associated with better 5-year recurrence-free survival (good responders: 81.1%, poor responders: 49.0%; p = 0.001) and 5-year overall survival (good responders: 94.9%, poor responders: 80.6%; p = 0.06). In a multivariate analysis, extramural venous invasion on magnetic resonance imaging after neoadjuvant chemotherapy and a tumor volume reduction rate < 60 were found to be significantly and independently associated with worse recurrence-free survival (hazard ratio: 2.74, 95% confidence interval: 1.36-5.50, p = 0.005 and hazard ratio: 3.48, 95% confidence interval: 1.57-7.72, p = 0.002, respectively). Good responders without extramural venous invasion had the best 5-year recurrence-free and overall survival (89.0 and 93.8%, respectively). Poor responders with extramural venous invasion had the worst 5-year recurrence-free and overall survival (21.4 and 50.0%, respectively).

CONCLUSIONS

Reductions in tumor volume after neoadjuvant chemotherapy were associated with a better prognosis in patients with locally advanced lower rectal cancer. Extramural venous invasion was a preoperative prognostic factor.

Endoscopy and magnetic resonance imaging-based prediction of ypT stage in patients with rectal cancer who received chemoradiotherapy: Results from a prospective study of 110 patients

Accurate tumor response determination remains inconclusive after preoperative chemoradiation therapy (CRT) for rectal cancer. This study aimed to investigate whether clinical assessment, such as endoscopy and magnetic resonance imaging (MRI), can accurately predict ypT stage and select candidates for pelvic organ-preserving surgery in rectal cancer after preoperative CRT. A total of 110 patients who underwent preoperative CRT followed by curative resection for rectal cancer were prospectively enrolled. Magnetic resonance tumor regression grade (mrTRG) using T2-MRI, endoscopic evaluation, and combination modality (combination of endoscopy and mrTRG) were used to analyze tumor response after preoperative CRT. Endoscopic findings were categorized as 3 grades and the mrTRG was assessed into 5 grades. Twenty-nine patients (26.4%) had achieved pathologic complete response. When predicting ypT0, endoscopy showed significantly higher area under the curve (AUC 0.818) than did mrTRG (AUC 0.568) and combination modality (AUC 0.768) in differentiating good response from poor response (P < .001). Both endoscopy and combination modality showed significantly higher diagnostic performance in sensitivity (79.31%), positive predictive value (PPV 67.65%), negative predictive value (NPV 92.11%), and accuracy (84.55%) than those of MR tumor response (sensitivity 37.93%, PPV 36.67%, NPV 77.50%, and accuracy 66.36%) for the prediction of ypT0 (P < .001). Combination modality showed significantly higher diagnostic performance in sensitivity (56.92%), NPV (56.92%), and accuracy (67.27%) compared with those of mrTRG. Neither endoscopy, nor mrTRG, nor the combination modality had adequate diagnostic performances to be clinically acceptable in selecting candidates for nonoperative treatment strategies. However, endoscopy may be incorporated in clinical restaging strategy in planning the extent of surgical resection in patients with rectal cancer.

Oncologic Outcomes in Patients Who Undergo Neoadjuvant Chemoradiotherapy and Total Mesorectal Excision for Locally Advanced Rectal Cancer: A 14-Year Experience in a Single Institution

PURPOSE

This study evaluated the oncologic outcomes of locally advanced rectal cancer patients who underwent preoperative neoadjuvant chemoradiotherapy (CRT) followed by surgery and determined the prognostic significance of pathologic complete response (pCR).

METHODS

Between January 2002 and December 2015, 580 patients with rectal cancer who underwent surgery after neoadjuvant CRT were identified. Survival according to tumor response to CRT and pathologic stage was analyzed using the Kaplan-Meier method, and the Cox proportional hazard model was used to identify factors associated with survival outcomes.

RESULTS

A total of 111 patients (23.7%) achieved pCR while the other 469 patients showed residual disease. Patients with pCR had a lower pretreatment carcinoembryonic antigen level and earlier cT classification than those with residual disease. With a median follow-up of 78 months, disease-free survival (DFS) and overall survival (OS) were significantly better in the pCR group than in the residual disease group. The 5-year DFS and 5-year OS for patients with ypStage 0, I, II, or III were 92.5%, 85.1%, 72.2%, 54.3% (P < 0.001) and 94.5%, 91.0%, 83.1%, 69.3%, respectively (P < 0.001). Pathologic AJCC stage after CRT was the most statistically significant independent predictor of OS (HR, 6.97 [95% confidence interval, 3.16-15.39] for stage III vs. stage 0) and DFS (HR, 7.30 [95% confidence interval, 3.63-14.67] for stage III vs. stage 0).

CONCLUSION

Rectal cancer patients who achieved pCR showed improved survival compared to those with residual disease after preoperative CRT. Moreover, pCR was an independent indicator of OS and DFS, and pathologic AJCC stage was correlated with survival after preoperative CRT.

Prognostic Impact of Perineural Invasion in Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND

Perineural invasion (PNI) has emerged as an important factor related to colorectal cancer spread; however, the impact of neoadjuvant chemoradiotherapy (nCRT) on PNI remains unclear. Herein, we investigated the prognostic value of PNI, along with lymphovascular invasion (LVI), in rectal cancer patients treated with nCRT.

METHODS

This single-center observational study of pathologic variables, including PNI and LVI, analyzed 1411 invasive rectal cancer patients (965 and 446 patients treated with primary resection and nCRT, respectively).

RESULTS

The overall detection rates of LVI and PNI were 16.7 and 28.8%, respectively. The incidence of LVI was significantly lower in patients treated with nCRT (8.1 vs. 20.6%, P < .001); this was confirmed by multivariate analysis. However, PNI was not affected by nCRT (with nCRT 28.3% vs. without nCRT 29.1%, P = .786). In the 446 patients with nCRT, multivariate analysis revealed that PNI was an independent prognostic factor for both disease-free survival (DFS) and overall survival (OS). For the prediction of both 5-year DFS and OS, the C-index for the combinations of T-stage with the PNI (TPNI) system showed favorable result, especially in patients with a total number of harvested lymph nodes <8.

CONCLUSION

PNI is a meaningful prognostic factor for rectal cancer patients treated with nCRT, especially when <8 lymph nodes are harvested. The lack of influence of nCRT on the PNI incidence suggests that residual tumor cells with PNI are more radioresistant or biologically aggressive than those without.

Neoadjuvant chemoradiation for locally advanced rectal cancer: a systematic review of the literature with network meta-analysis

Background

Neoadjuvant chemoradiotherapy (CRT) prior to surgery is a standard therapy for locally advanced rectal cancer, but the optimum regime is not conclusive. This meta-analysis evaluated various CRT regimens with regard to the rate of pathologic complete response (pCR) and toxic effects of grade ≥3.

Methods

The databases PubMed, Cochrane Library, and Embase were searched for randomized controlled trials (RCTs) that compared neoadjuvant CRT regimes for treating patients with locally advanced rectal cancer, published before 28 December 2017. The primary end points were pCR and toxic effects. A network meta-analysis was applied.

Results

Fourteen RCTs (with 5,599 participants) involving the following eight regimens were included: fluorouracil (5FU) alone, or 5FU with oxaliplatin (OXA), cisplatin, or irinotecan (CPT-11); capecitabine (CAP) alone, or CAP with OXA or CPT-11; and CPT-11 with combined tegafur, 5-chloro-2,4-dihydroxypyridine, and potassium oxonate. The rate of pCR associated with CAP + OXA was significantly higher compared with 5FU alone; there were no significant differences among the other regimens. The toxicity of 5FU + OXA or CAP + OXA was significantly worse than that of 5FU alone or CAP alone. CAP + OXA and CAP were ranked, respectively, the most and second most effective regimens in terms of pCR rate. 5FU alone and CAP alone likely had the lowest and second lowest toxicity, respectively.

Conclusion

Among the currently available CRT regimens for locally advanced rectal cancer, this meta-analysis indicated that CAP + OXA provides the superior clinical results. Adding OXA to 5FU or CAP significantly increases toxicity.

Is adjuvant chemotherapy necessary for patients with ypT0-2N0 rectal cancer treated with neoadjuvant chemoradiotherapy and curative surgery?

Background and objective

The benefit from adjuvant chemotherapy for patients treated with neoadjuvant chemoradiotherapy (NCRT) and curative surgery remains controversial, particularly among those responding well to NCRT. This retrospective study aimed to clarify the benefits of adjuvant chemotherapy in terms of the oncological outcomes of patients with ypT0–2N0 rectal cancer after NCRT and curative surgery.

Methods

All patients with ypT0–2N0 rectal cancer after NCRT and curative resection between 2005 and 2014 were examined. The oncological outcomes between patients treated with adjuvant chemotherapy and those without any chemotherapy were compared.

Results

The clinicopathological characteristics of 110 patients were reviewed in this study; one patient was excluded due to lack of follow-up. Of the 109 patients included, 58 (53.2%) underwent adjuvant chemotherapy (chemo group), whereas the remaining 51 (46.8%) did not receive any chemotherapy (non-chemo group). After a median follow-up of 50 months, there were no significant differences in the 5-year overall survival (OS) or recurrence-free survival (RFS) rates between the groups (OS: 92.1 vs 86.3%, P = 0.375; RFS: 80.9 vs 74.7%, P = 0.534). Subgroup analysis also demonstrated no significant differences in 5-year OS and RFS rates between patients with ypT0N0 rectal cancer (P = 0.712 and P = 0.599, respectively) and those with ypT1–2N0 disease (P = 0.255 and P = 0.278, respectively).

Conclusions

These results indicate that patients with ypT0–2N0 rectal cancer after NCRT followed by curative surgery may not derive significant benefit from adjuvant chemotherapy. However, further prospective randomized trials, with larger sample sizes, are warranted to confirm this conclusion.

Persistent Problems in Colorectal Cancer Reporting

Tumor stage, as determined by the Tumor, Node, Metastasis (TNM) staging system, is the single most influential factor determining treatment decisions and outcome among patients with colorectal cancer. Several stage-related elements in pathology reports consistently pose diagnostic challenges: recognition of serosal penetration by tumor (ie, pT3 vs pT4a), evaluation of regional lymph nodes, distinction between tumor deposits and effaced lymph nodes, and assessment of tumor stage in the neoadjuvant setting. This article discusses each of these issues in detail and provides practical tips regarding colorectal cancer staging.

MRI-based EMVI positivity predicts systemic recurrence in rectal cancer patients with a good tumor response to chemoradiotherapy followed by surgery

BACKGROUND

This study aimed to determine the prognostic value of baseline magnetic resonance imaging-based extramural vascular invasion status (EMVI) among rectal cancer patients with a good tumor response to standard chemoradiotherapy followed by surgery.

METHODS

A total of 359 patients with ypT0-2/N0 disease from The Yonsei Multicenter Colorectal Cancer Electronic Database were retrospectively included between January 2000 and December 2014. Magnetic resonance images and medical records were reviewed to investigate risk factors for tumor recurrence.

RESULTS

When we compared patients without and with EMVI, significant differences were observed in the 5-year disease-free survival rate (DFS) (80.8% vs 57.8%, P = 0.005) and in the 5-year systemic recurrence-free survival rate (SRFS) (86.9% vs 64.3%, P = 0.007). In the multivariate analysis, both mrEMVI and APR independently predicted overall DFS (APR; HR 2.088, 95% CI: 1.082-4.031, P = 0.028, mrEMVI; HR: 2.729, 95% CI: 1.230-6.058, P = 0.014). mrEMVI was only independent prognostic factor for systemic recurrence with statistical significance (HR: 3.321, 95% CI: 1.185-9.309, P = 0.022).

CONCLUSION

Even in rectal cancer patients with a good response to chemoradiotherapy followed by curative surgery, extramural vascular invasion and APR may predict poor disease-free survival outcomes. Intensified treatment strategy should be considered.

Is the pathological regression level of metastatic lymph nodes associated with oncologic outcomes following preoperative chemoradiotherapy in rectal cancer?

Purpose

The oncologic impact of the lymph node (LN) regression level after preoperative chemoradiotherapy (PCRT) has not been thoroughly evaluated. Hence, this study aimed to examine whether the regression level of metastatic LNs following PCRT is associated with oncologic outcomes in rectal cancer.

Results

The optimal number of cut points for LRG sum was determined to be three. The three LRG groups demonstrated different distributions according to the ypT and ypN stages (p < 0.001 for both). However, the distribution of the LRG groups was not associated with the TRG of the primary tumor (p = 0.527). The RFS significantly differed according to the LRG groups (p = 0.001). Moreover, the differences in RFS remained when the LRG groups were analyzed within each separate ypN stage. The LRG group was confirmed as a factor associated with RFS in the multivariate analysis (p=0.018), while the ypN stage was not (p=0.4).

Patients and Methods

We analyzed the outcomes of 142 rectal cancer patients diagnosed with ypN1 disease after PCRT followed by radical resection. The pathological responses of the primary tumor and LNs to PCRT were evaluated using the tumor regression grade (TRG) and LN regression grade (LRG), respectively. The impact of LRG on recurrence-free survival (RFS) was analyzed. The K-adaptive partitioning for survival data method was applied to determine the optimal number of cut points for the LRG-sum and the optimal number of subgroups.

Conclusion

The LRG as an indicator of response to PCRT should be considered as a prognostic determinant in rectal cancer patients. Future large-scale prospective studies are needed to confirm this finding.

Novel radiomic signature as a prognostic biomarker for locally advanced rectal cancer

BACKGROUND

Locally advanced rectal cancer (LARC) patient stratification by clinicoradiologic factors may yield variable results. Therefore, more efficient prognostic biomarkers are needed for improved risk stratification of LARC patients, personalized treatment, and prognostication.

PURPOSE/HYPOTHESIS

To compare the ability of a radiomic signature to predict disease-free survival (DFS) with that of a clinicoradiologic risk model in individual patients with LARC.

STUDY TYPE

Retrospective study.

POPULATION

In all, 108 consecutive patients (allocated to a training and validation set with a 1:1 ratio) with LARC treated with neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME).

FIELD STRENGTH/SEQUENCE

Axial 3D LAVA multienhanced MR sequence at 3T.

ASSESSMENT

ITK-SNAP software was used for manual segmentation of 3D pre-nCRT MR images. All manual tumor segmentations were performed by a gastrointestinal tract radiologist, and validated by a senior radiologist. The clinicoradiologic risk factors with potential prognostic outcomes were identified in univariate analysis based on the Cox regression model for the whole set. The results showed that ypT, ypN, EMVI, and MRF were potential clinicoradiologic risk factors. Interestingly, only ypN and MRF were identified as independent predictors in multivariate analysis based on the Cox regression model.

STATISTICAL TESTS

A radiomic signature based on 485 3D features was generated using the least absolute shrinkage and selection operator (LASSO) Cox regression model. The association of the radiomic signature with DFS was investigated by Kaplan-Meier survival curves. Survival curves were compared by the log-rank test. Three models were built and assessed for their predictive values, using the Harrell concordance index and integrated time-dependent area under the curve.

RESULTS

The novel radiomic signature stratified patients into low- and high-risk groups for DFS in the training set (hazard ratio [HR] = 6.83; P < 0.001), and was successfully validated in the validation set (HR = 2.92; P < 0.001). The model combining the radiomic signature and clinicoradiologic findings had the best performance (C index = 0.788, 95% confidence interval [CI] 0.72-0.86; integrated time-dependent area under the curve of 0.837 at 3 years).

DATA CONCLUSION

The novel radiomic signature could be used to predict DFS in patients with LARC. Furthermore, combining this radiomic signature with clinicoradiologic features significantly improved the ability to estimate DFS (P = 0.001, 0.005 in training set and in validation set, respectively), and may help guide individualized treatment in such patients.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018.

Comparison between Intensified Neoadjuvant Treatment and Standard Preoperative Chemoradiation for Rectal Cancer

Objectives

The aim of the current study was to compare a neoadjuvant regimen containing oxaliplatin with standard preoperative treatment for rectal cancer.

Methods

From December 2006 to December 2007, 20 patients with rectal cancer were treated at our Institution with the weekly addition of oxaliplatin (50 mg/m2) to radiotherapy (50.4–54.0 Gy in 28–30 daily fractions) and continuous infusion of 5-fluorouracil (200 mg/m2). The results of the regimen were compared with a historical control group including 21 consecutive patients previously treated with standard 5-fluorouracil treatment from December 2004 to October 2006.

Results

Both the rate of sphincter preservation in low rectal cancer (91.7% vs 36.4%, P = 0.009) and the rate of downstaging (84.2% vs 47.6%, P = 0.023) were higher in the oxaliplatin group than in the control group. Pathological complete response was achieved in 8 patients (42.1%) in the oxaliplatin group and in 4 patients (19.0%) in the control group (P = 0.172). When ypT0-pT1 stages were analyzed together, the P value was 0.051. Acute toxicity was increased in the oxaliplatin group, with a higher incidence of G3 diarrhea and pelvic pain than in the control group (30.0% vs 14.3%, P = NS).

Conclusions

Our data seem to correlate the addition of oxaliplatin to the standard treatment for rectal cancer with higher rates of sphincter preservation, down-staging and complete response. Toxicity is increased and requires careful monitoring. However, our results refer to a retrospective comparison of a small series of patients and need to be validated by the large, phase III randomized trial currently ongoing.

Exercise during and after neoadjuvant rectal cancer treatment (the EXERT trial): study protocol for a randomized controlled trial

Background

Standard treatment for locally advanced rectal cancer includes 5–6 weeks of neoadjuvant chemoradiotherapy (NACRT) followed by total mesorectal excision 6–8 weeks later. NACRT improves local disease control and surgical outcomes but also causes side effects including fatigue, diarrhea, hand-foot syndrome, and physical deconditioning that may impede quality of life (QoL), treatment completion, treatment response, and long-term prognosis. Interventions to improve treatment outcomes and manage side effects that are safe, tolerable and low-cost are highly desirable. Exercise has been shown to improve some of these outcomes in other cancer patient groups but no study to date has examined the potential benefits (and harms) of exercise training during and after NACRT for rectal cancer.

Methods/design

The Exercise During and After Neoadjuvant Rectal Cancer Treatment (EXERT) trial is a single-center, prospective, two-armed, phase II randomized controlled trial designed to test the preliminary efficacy of exercise training in this clinical setting and to further evaluate its feasibility and safety. Participants will be 60 rectal cancer patients scheduled to receive long-course NACRT followed by total mesorectal excision. Participants will be randomly assigned to exercise training or usual care. Participants in the exercise training group will be asked to complete three supervised, high-intensity interval training sessions/week during NACRT and ≥ 150 min/week of unsupervised, moderate-to-vigorous-intensity, continuous exercise training after NACRT prior to surgery. Participants in the usual care group will be asked not to increase their exercise from baseline. Assessments will be completed pre NACRT, post NACRT, and pre surgery. The primary endpoint will be cardiorespiratory fitness (VO₂ peak) at the post-NACRT time point assessed by a graded exercise test. Secondary endpoints will include functional fitness assessed by the Senior’s Fitness Test, QoL assessed by the European Organisation of Research and Treatment of Cancer, and symptom management assessed by the M.D. Anderson Symptom Inventory. Exploratory clinical endpoints will include treatment toxicities, treatment completion, treatment response, and surgical complications.

Discussion

If the preliminary findings of EXERT are positive, additional research will be warranted to confirm whether exercise is an innovative treatment to maintain QoL, manage side effects, and/or improve treatment outcomes in rectal cancer patients.

Trial registration

ClinicalTrials.gov, ID: NCT03082495. Registered on 9 February, 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2398-1) contains supplementary material, which is available to authorized users.

Prognostic Significance of Tumor Regression in Locally Advanced Rectal Cancer after Preoperative Radiochemotherapy

Background

The majority of rectal cancers are discovered in locally advanced forms (UICC stage II, III). Treatment consists of preoperative radiochemotherapy, followed by surgery 6–8 weeks later and finally by postoperative chemotherapy. The aim of this study was to find out if tumor regression affected long-term survival in patients with localy advanced rectal cancer, treated with neoadjuvant radiochemotherapy.

Patients and methods

Patients with rectal cancer stage II or III, treated between 2006 and 2010, were included in a retrospective study. Clinical and pathohistologic data were acquired from computer databases and information about survival from Cancer Registry. Survival was estimated according to Kaplan-Meier method. Significance of prognostic factors was evaluated in univariate analysis; comparison was carried out with log-rank test. The multivariate analysis was performed according to the Cox regression model; statistically significant variables from univariate analysis were included.

Results

Two hundred and two patients met inclusion criteria. Median follow-up was 53.2 months. Stage ypT0N0 (pathologic complete response, pCR) was observed in 14.8% of patients. Pathohistologic stage had statistically significant impact on survival (p = 0.001). 5-year survival in patients with pCR was>90%. Postoperative T and N status were also found to be statistically significant (p = 0.011 for ypT and p < 0.001 for ypN). According to multivariate analysis, tumor response to neoadjuvant therapy was the only independent prognostic factor (p = 0.003).

Conclusions

Pathologic response of tumor to preoperative radiochemotherapy is an important prognostic factor for prediction of long-term survival of patients with locally advanced rectal cancer.

Oncologic Outcome of ypT1-2N0 Rectal Cancer After Neoadjuvant Chemoradiotherapy Compared With pT1-2N0 Rectal Cancer

OBJECTIVE

To investigate the oncologic outcome of ypT1-2N0 mid and lower rectal cancer after chemoradiotherapy (CRT) compared with pT1-2N0 rectal cancer.

METHODS

We compared the oncologic outcome of patients with mid and lower rectal cancer who underwent preoperative CRT and who did not, between February 2005 and August 2012.

RESULTS

Compared with patients who did not receive preoperative CRT, patients who received preoperative CRT did not have significantly different clinicopathologic features except clinical stage and distal resection margin. The 5-year disease-free survival (DFS) rates were lower in patients who received preoperative CRT than those who did not (84.4% vs. 95.5%, P=0.029). Preoperative CRT was a prognostic factor affecting 5-year DFS in patients with pathologically proven stage T1N0 mid and lower rectal cancer (HR, 11.157; 95% CI, 1.735-71.762; P=0.011) CONCLUSIONS:: ypT2N0 rectal cancer after neoadjuvant CRT showed shorter DFS compared with pT2N0 rectal cancer.

Adjuvant Second-Dose Chemotherapy before Surgery for Patients with Locally Advanced Rectal Malignancy Is Not Beneficial: A Systematic Review and Meta-Analysis

BACKGROUND

Preoperative chemoradiotherapy is the standard treatment for patients with locally advanced rectal cancer, although tumor responses vary widely; some patients may achieve a pathologic complete response rate (pCR) after chemoradiotherapy. Controversy exists with regard to the efficacy of different preoperative combination chemotherapy regimens and neoadjuvant chemoradiotherapy, compared with chemoradiotherapy alone.

METHODS

PubMed, the Cochrane Library, and Embase databases were searched for comparative studies of patients with locally advanced rectal cancer that were published between January 1991 and January 2016. Efficacies of different preoperative combination chemotherapy regimens and neoadjuvant chemoradiotherapy (group A) were compared with chemoradiotherapy alone (group B) in a meta-analysis using Review Manager v5.2.

RESULTS

Three prospective randomized controlled trials and two prospective nonrandomized controlled trials comprising 444 cases were eligible for analysis. No significant difference was detected in the rate of pCR (50/223, 22.4% versus 35/223, 15.7%; relative risk, RR: 1.42 [95% confidence interval, CI: 0.97-2.09], p = 0.07) between the two groups. The rate of tumor regression was similar for both groups (122/203, 60.1% versus 111/203, 54.7%; RR: 1.11 [95% CI: 0.94-1.29], p = 0.22).

CONCLUSIONS

Adjuvant chemotherapy with preoperative chemoradiotherapy did not significantly improve the rate of pCR nor the rate of T and N downstaging.

A Modified Classification of Prognostic Factors Based on Pathological Stage and Tumor Regression Grade in Patients with Rectal Cancer Who Receive Preoperative Chemoradiotherapy

OBJECTIVE

The histologic response to neoadjuvant chemoradiotherapy (CRT) has been intimately related to outcomes in locally advanced rectal cancer. However, reliable prognostic factors have yet to be established.

SUBJECTS AND METHODS

The study group comprised 198 patients with locally advanced rectal cancer who received CRT. A modified classification based on the combination of ypStage and tumor regression grade (TRG) was developed. ypStage II with TRG 2 was classified as ypTRGstage IIA, and ypStage II with TRG 3 or 4 was classified as ypTRGstage IIB. ypStage 0 and ypStage I were classified as ypTRGstage I, and ypStage III was classified as ypTRGstage III.

RESULTS

The 5-year disease-free survival (DFS) was 83% in ypTRGstage I, 86% in ypTRGstage IIA, 57% in ypTRGstage IIB, and 60% in ypTRGstage III (p = 0.0001). The 5-year DFS in ypTRGstage IIA did not differ significantly from that in ypStage 0 (p = 0.865) or ypStage I (p = 0.585). The 5-year DFS in ypStage IIB did not differ from that in ypStage III (p = 0.912). Multivariate analysis showed that ypTRGstage was an independent risk factor for DFS.

CONCLUSION

A modified classification allows patients with ypStage II locally advanced rectal cancer to be clearly divided into two groups: responders and nonresponders.

Prognostic significance of tumour regression grade after neoadjuvant chemoradiotherapy for a cohort of patients with locally advanced rectal cancer: an 8-year retrospective single-institutional study

AIM

Locally advanced rectal cancer (LARC) is frequently treated with neoadjuvant chemoradiotherapy (NACRT) to reduce the risk of local recurrence and improve survival. Tumour response to NACRT is variable and may influence the prognosis after subsequent surgery. This study compared the prognostic values of tumour regression grade (TRG) and neoadjuvant pathological (ypTNM) downstaging in patients with Stage II and III rectal cancer treated with NACRT followed by curative surgery.

METHOD

This study included 185 patients with LARC treated with long-course radiotherapy (45 Gy in 25 fractions) plus 5-fluorouracil over 5 weeks between 2005 and 2013. We used multivariate analysis to assess the relationship of Dworak's five-tier TRG, ypTNM stage and ypTNM downstaging with clinicopathological factors, 5-year disease-free survival (DFS) and 5-year overall survival (OS).

RESULTS

Total regression (TRG4), good regression (TRG3), moderate regression (TRG2), minor regression (TRG1) and no regression (TRG0) were seen in 38 (20.6%), 65 (35.2%), 43 (23.2%), 28 (15.1%) and 11 (5.9%) patients, respectively. TNM downstaging following NACRT occurred in 109 (58.9%) patients. The 5-year DFS rates after NACRT for TRG0, TRG1, TRG2, TRG3 and TRG4 were 0%, 58.5%, 66.4%, 80.4% and 82.6%, respectively (P < 0.001). The ypTNM stage correlated with 5-year DFS (P = 0.004) but not 5-year OS (P = 0.075). Multivariate analysis demonstrated that TRG was related to both DFS and OS (P < 0.001).

CONCLUSION

TRG measured on a five-tier system was better than ypTNM stage for predicting outcome in patients with LARC treated with NACRT and surgery.

Efficacy and safety of neoadjuvant chemotherapy with oxaliplatin, 5-fluorouracil, and levofolinate for T3 or T4 stage II/III rectal cancer: the FACT trial

PURPOSE

A multicenter phase II clinical study was performed in patients with T3 or T4 stage II/III rectal cancer to evaluate the efficacy and safety of neoadjuvant chemotherapy with 5-fluorouracil, levofolinate, and oxaliplatin (mFOLFOX6).

METHODS

Patients received four 2-week cycles of mFOLFOX6 therapy (oxaliplatin at 85 mg/m² + leucovorin at 200 mg/m² + fluorouracil as a 400 mg/m² bolus followed by infusion of 2400 mg/m² over 46 h, all on Day 1). They were evaluated by computed tomography after completion of the fourth cycle. If there was no disease progression, two additional cycles were administered and then surgery was performed. Adjuvant chemotherapy was generally administered for 6 months using appropriate regimens at the discretion of the physician.

RESULTS

mFOLFOX6 therapy was given to 52 patients with locally advanced rectal cancer. The preoperative response rate was 48.8% and the operation rate was 80.8%. Serious adverse events of Grade 3-4 were neutropenia (n = 5), leukopenia (n = 1), thrombocytopenia (n = 1), febrile neutropenia (n = 1), nausea (n = 1), vomiting (n = 1), and peripheral neuropathy (n = 2). The R0 resection rate, pathologic complete response rate, and sphincter preservation rate were 91.0, 11.9, and 73.8%, respectively. Postoperative complications were tolerable.

CONCLUSIONS

The present results suggested that neoadjuvant therapy with mFOLFOX6 is safe and effective, representing a reasonable treatment option for locally advanced rectal cancer.

A nomogram to predict distant metastasis after neoadjuvant chemoradiotherapy and radical surgery in patients with locally advanced rectal cancer

PURPOSE

To compare distant metastasis (DM) in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (nCRT) and surgery alone, and to develop a predictive nomogram for DM following nCRT.

METHODS

Propensity-scoring match analysis was performed to compare DM in LARC treated with nCRT (n = 375) and surgery alone (n = 375). Cox regression was performed to identify predictors of DM following nCRT. A nomogram was developed and validated by internal (n = 425) and external validation (n = 97).

RESULTS

The 5-year local recurrence rate was significantly lower in the nCRT group (5.6% vs. 10.4%; P = 0.020). The 5-year DM rates (nCRT vs. surgery alone: 25.3% vs. 24.4%; P = 0.235) were similar between groups. Cox regression showed that the post-nCRT pathologic stage (ypTNM stage, OR = 2.022, P = 0.002), IMA nodal metastasis (OR = 2.171, P = 0.023), and CRM involvement (OR = 2.535, P = 0.016) were independently associated with DM following nCRT. A predictive nomogram was developed with a C-index of 0.70 on internal validation, and 0.71 on the external validation.

CONCLUSION

NCRT improved local control, but not distant metastasis. A nomogram to predict 3- and 5-year DM rates, using clinicopathological parameters, was successfully developed. This prognostic tool could support decision-making in clinical practice and follow-up strategies.

The clinicopathologic relevance and prognostic value of tumor deposits and the applicability of N1c category in rectal cancer with preoperative radiotherapy

The clinicopathologic relevance and prognostic value of tumor deposits in colorectal cancer has been widely demonstrated. However, there are still debates in the prognostic value of tumor deposits and the applicability of N1c category in rectal cancer with preoperative radiotherapy. In this study, rectal cancer with preoperative radiotherapy followed by resection of primary tumors registered in Surveillance, Epidemiology and End Results (SEER) database from 2010-2012 were analyzed. There were 4,813 cases eligible for this study, and tumor deposits were found in 514 (10.7%) cases. The presence of tumor deposits was significantly associated with some aggressive characteristics, including poorer tumor differentiation, more advanced ypT category, ypN category and ypTNM stage, distant metastasis, elevated carcinoembryonic antigen, higher positive rates of circumferential resection margin and perineural invasion (all P < = 0.001). Tumor deposit was also an independent negative prognostic factor for cancer-specific survival in rectal cancer with preoperative radiotherapy (adjusted HR and 95% CI: 2.25 (1.51 - 3.35)). N1c category had significant worse survival compared with N0 category (adjusted HR and 95% CI: 2.41 (1.24 - 4.69)). In conclusion, tumor deposit was a significant and independent prognostic factor, and the N1c category by the 7th edition of AJCC/TNM staging system was applicable in rectal cancer with preoperative radiotherapy.

An observational study of extending FOLFOX chemotherapy, lengthening the interval between radiotherapy and surgery, and enhancing pathological complete response rates in rectal cancer patients following preoperative chemoradiotherapy

INTRODUCTION

Patients with rectal cancer who exhibit a pathologic complete response to preoperative concurrent chemoradiotherapy have excellent oncologic outcomes. In this study, we evaluated the potential advantages of adding oxaliplatin to preoperative fluoropyrimidine-based chemoradiotherapy administered in rectal cancer patients.

METHODS

A total of 78 patients with rectal cancer were enrolled. Patients were administered chemoradiotherapy, which comprised radiotherapy and chemotherapy involving a 5-fluorouracil, leucovorin, and oxaliplatin regimen every 2 weeks. Surgery was performed 10-12 weeks after radiotherapy completion. Tumor regression, adverse events, surgical complications, and short-term clinical outcomes were recorded.

RESULTS

Two patients were excluded because of incomplete radiotherapy treatment or refusal of surgery. Eventually, 76 patients underwent total mesorectal excision and no perioperative mortality was observed. Of these, 20 patients (25.6%) developed grade 3 or 4 toxicity during concurrent chemoradiotherapy. Among the 76 patients who underwent surgery, 24 (31.6%) patients achieved a pathologic complete response. The sphincter preservation rate was 96.1% (73/76) in all patients and 92.2% (39/42) in patients with tumors located less than 5 cm from the anal verge. The 2-year overall and disease-free survivals were 94% and 87.4%, respectively.

CONCLUSION

The intensified multimodality therapy was well tolerated in our cohort and resulted in a considerably high pathologic complete response rate. Regardless of favorable short-term clinical outcomes, long-term oncologic outcomes will be closely monitored among the patients with a pathologic complete response.

Pathologic response to neoadjuvant treatment in locally advanced rectal cancer and impact on outcome

BACKGROUND

Downstaging and pathologic complete response (pCR) after chemoradiotherapy (CRT) may improve progression-free survival and overall survival (OS) after curative therapy of locally advanced adenocarcinoma of rectum. The purpose of this study is to evaluate the pathologic response subsequent to neoadjuvant chemoradiation in locally advanced rectal adenocarcinoma and any impact of response on oncological outcome [disease-free survival (DFS), OS].

METHODS

A total of 127 patients with histologically-proven rectal adenocarcinoma, locally advanced, were treated with preoperative radiotherapy and concurrent 5-fluorouracil (5 FU), and followed by curative surgery. Pathologic response to neoadjuvant treatment was evaluated by comparing pathologic TN (tumour and nodal) staging (yp) with pre-treatment clinical staging. DFS and OS were compared in patients with: pCR, partial pathologic response and no response to neoadjuvant therapy.

RESULTS

14.96% (19 patients) had a pCR, 58.27% [74] showed downstaging and 26.77% [34] had no change in staging. At follow-up (range, 4-9 years, median 6 years 2 months or 74 months), 17.32% [22] showed recurrence: 15.74% [20] distant metastasis, 1.57% [2] pelvic failure. 10.5% [2] of the patients with pCR showed distant metastasis, none showed local recurrence. In the downstaged group, nine developed distant failure and two had local recurrence (14.86%). Distant failure was seen in 26.47% [9] of those with no response to neoadjuvant treatment. DFS and OS rates for all groups were 82.67% and 88.97% respectively. Patients with pCR showed 89.47% DFS and 94.7% OS. In partial responders, DFS was 85.1% and OS was 90.5%. In non-responders, DFS and OS were 73.5% and 82.3% respectively. Patients with pCR had a significantly greater probability of DFS and OS than non-responders. Rectal cancer-related death was 11.02% [14]: one patient (5.26%) with pCR, 9.47% [7] in the downstaged group and 17.64% [6] of non-responders.

CONCLUSIONS

The majority of patients showed some response to neoadjuvant treatment. Findings of this study indicate tumour response to neoadjuvant CRT improves the long-term outcome, with a better result in patients with pCR.