Circumferential margin involvement is the crucial prognostic factor after multimodality treatment in patients with locally advanced rectal carcinoma

Identification of radiologic and clinicopathologic variables associated with tumor regression pattern and distribution of cancer cells after short-course radiotherapy and consolidation chemotherapy in patients with rectal cancer

Background

Knowledge of the pattern of regression and distribution of residual tumor cells may assist in the selection of candidates for rectum-sparing strategies.

Objective

To investigate and identify factors associated with tumor regression pattern and distribution of residual tumor cells.

Methods

We conducted a prospective study of patients with T3/T4 N0/N+ adenocarcinoma of the middle and lower third of the rectum (≤10 cm) treated with radiotherapy (5×5 Gy) followed by 6 cycles of CAPOX chemotherapy. The pattern of tumor regression was classified as fragmented or solid. Microscopic intramural spread was measured. We used a model of distribution of residual tumor cells not yet applied to rectal cancer, defined as follows: type I (luminal), type II (invasive front), type III (concentric), and type IV (random).

Results

Forty patients were included with a median age of 66 years; 23 (57.5%) were men. A fragmented pattern was identified in 18 patients (45.0%), and a solid pattern in 22 (55.0%). Microscopic intramural spread was identified in 25 patients (62.5%), extending from 1 to 18 mm (median, 4 mm). There were 14 cases (35.0%) of microscopic intramural spread ≥10 mm. All cases of fragmented regression pattern, except one, showed microscopic intramural spread. Within the fragmented pattern, microscopic intramural spread was 4-8 mm in 4 cases and ≥10 mm in the remaining cases. All cases of microscopic intramural spread ≥ 10 mm were within the fragmented pattern. Regarding the distribution pattern of residual tumor cells, 11 cases (31.5%) were classified as type I, 14 (40.0%) as type II, 10 (28.5%) as type III, and none as type IV. Carcinoembryonic antigen levels >5 ng/mL, downsizing <50%, residual mucosal abnormality >20 mm, and anatomopathologic lymph node involvement were significantly associated with the occurrence of fragmentation (P<0.05). Having received all 6 cycles of CAPOX chemotherapy and absence of microscopic intramural spread were significantly associated with the type I distribution pattern (P<0.05).

Conclusion

The occurrence of a fragmented regression pattern is common, as is the presence of microscopic intramural spread. We could identify radiologic and clinicopathologic factors associated with the pattern of tumor regression and a type I distribution pattern.

Progress of MRI in predicting the circumferential resection margin of rectal cancer: A narrative review

Rectal cancer (RC) is the third most frequently diagnosed cancer worldwide, and the status of its circumferential resection margin (CRM) is of paramount significance for treatment strategies and prognosis. CRM involvement is defined as tumor touching or within 1 mm from the outermost part of tumor or outer border of the mesorectal or lymph node deposits to the resection margin. The incidence of involved CRM varied from 5.4 % to 36 %, which may associate with an in consistent definition of CRM, the quality of surgeries, and the different examination modalities. Although T and N status are essential factors in determining whether a patient should receive neoadjuvant therapy before surgery, CRM status is a powerful predictor of local and distant recurrence as well as survival rate. This review explores the significance of CRM, the various assessment methods, and the role of magnetic resonance imaging (MRI) and artificial intelligence-based MRI in predicting CRM status. MRI showed potential advantage in predicting CRM status with a high sensitivity and specificity compared to computed tomography (CT). We also discuss MRI advancements in RC imaging, including conventional MRI with body coil, high-resolution MRI with phased-array coil, and endorectal MRI. Along with a discussion of artificial intelligence-based MRI techniques to predict the CRM status of RCs before and after treatments.

Relevance of shrinkage versus fragmented response patterns in rectal cancer

AIMS

Partial response to neoadjuvant chemoradiotherapy (CRT) presents with one of two main response patterns: shrinkage or fragmentation. This study investigated the relevance of these response patterns in rectal cancer, correlation with other response indicators, and outcome.

METHODS AND RESULTS

The study included a test (n = 197) and a validation cohort (n = 218) of post-CRT patients with rectal adenocarcinoma not otherwise specified and a partial response. Response patterns were scored by two independent observers using a previously developed three-step flowchart. Tumour regression grading (TRG) was established according to both the College of American Pathologists (CAP) and Dworak classifications. In both cohorts, the predominant response pattern was fragmentation (70% and 74%), and the scoring interobserver agreement was excellent (k = 0.85). Patients with a fragmented pattern presented with significantly higher pathological stage (ypTNM II-IV, 78% versus 35%; P < 0.001), less tumour regression with Dworak (P = 0.004), and CAP TRG (P = 0.005) compared to patients with a shrinkage pattern. As a predictor of prognosis, the shrinkage pattern outperformed the TRG classification and stratified patients better in overall (fragmented pattern, hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.19-3.50, P = 0.008) and disease-free survival (DFS; fragmented pattern, HR 2.50, 95% CI 1.23-5.10, P = 0.011) in the combined cohorts. The multivariable regression analyses revealed pathological stage as the only independent predictor of DFS.

CONCLUSIONS

The heterogeneous nature of tumour response following CRT is reflected in fragmentation and shrinkage. In rectal cancer there is a predominance of the fragmented pattern, which is associated with advanced stage and less tumour regression. While not independently associated with survival, these reproducible patterns give insights into the biology of tumour response.

Size and depth of residual tumor after neoadjuvant chemoradiotherapy in rectal cancer - implications for the development of new imaging modalities for response assessment

With the shift towards organ preserving treatment strategies in rectal cancer it has become increasingly important to accurately discriminate between a complete and good clinical response after neoadjuvant chemoradiotherapy (CRT). Standard of care imaging techniques such as CT and MRI are well equipped for initial staging of rectal tumors, but discrimination between a good clinical and complete response remains difficult due to their limited ability to detect small residual vital tumor fragments. To identify new promising imaging techniques that could fill this gap, it is crucial to know the size and invasion depth of residual vital tumor tissue since this determines the requirements with regard to the resolution and imaging depth of potential new optical imaging techniques. We analyzed 198 pathology slides from 30 rectal cancer patients with a Mandard tumor regression grade 2 or 3 after CRT that underwent surgery. For each patient we determined response pattern, size of the largest vital tumor fragment or bulk and the shortest distance from the vital tumor to the luminal surface. The response pattern was shrinkage in 14 patients and fragmentation in 16 patients. For both groups combined, the largest vital tumor fragment per patient was smaller than 1mm for 38% of patients, below 0.2mm for 12% of patients and for one patient as small as 0.06mm. For 29% of patients the vital tumor remnant was present within the first 0.01mm from the luminal surface and for 87% within 0.5mm. Our results explain why it is difficult to differentiate between a good clinical and complete response in rectal cancer patients using endoscopy and MRI, since in many patients submillimeter tumor fragments remain below the luminal surface. To detect residual vital tumor tissue in all patients included in this study a technique with a spatial resolution of 0.06mm and an imaging depth of 8.9mm would have been required. Optical imaging techniques offer the possibility of detecting majority of these cases due to the potential of both high-resolution imaging and enhanced contrast between tissue types. These techniques could thus serve as a complimentary tool to conventional methods for rectal cancer response assessment.

Prognostication and optimal criteria of circumferential margin involvement for esophageal cancer after chemoradiation and esophagectomy

Purpose

Circumferential radial margin (CRM) involvement by tumor after resection for esophageal cancer has been suggested as a significant prognostic factor. However, the prognostic value of CRM involvement after surgery with neoadjuvant concurrent chemoradiotherapy (CCRT) is unclear. This study aimed to evaluate the prognostic value of and survival outcomes in CRM involvement as defined by the Royal College of Pathologists (RCP) and the College of American Pathologists (CAP) for patients with esophageal cancer undergoing neoadjuvant CCRT and esophagectomy.

Methods

A total of 299 patients with esophageal cancer who underwent neoadjuvant CCRT followed by esophagectomy between 2006 and 2016 were enrolled in our study. The CRM status of the specimens obtained was determined pathologically according to both the CAP and RCP criteria. Survival analyses were performed and compared according to the two criteria.

Results

Positive CRM was found in 102 (34.1%) and 40 (13.3%) patients according to RCP and CAP criteria, respectively. The overall and progression-free survival rates were significantly lower in the CRM-positive group than in the CRM-negative group according to both the RCP and CAP criteria. However, under multivariate analysis, in addition to pathological T and N staging of the tumor, only CAP-defined CRM positivity was a significant prognostic factor with adjusted hazard ratios of 2.64 (1.56-4.46) and 2.25 (1.34-3.78) for overall and progression-free survival, respectively (P < 0.001).

Conclusion

In patients with esophageal cancer undergoing neoadjuvant CRT followed by esophagectomy, CAP-defined CRM positivity is an independent predictor of survival. Adjuvant therapy should be offered to patients with positive CRM.

Bladder preservation or complete cystectomy during pelvic exenteration of patients with locally advanced or recurrent rectal cancer, what should we do?

INTRODUCTION

In patients with locally advanced (LARC) or locally recurrent (LRRC) rectal cancer and bladder involvement, pelvic exenteration (PE) with partial (PC) or radical (RC) cystectomy can potentially offer a cure. The study aim was to compare PC and RC in PE patients in terms of oncological outcome, post-operative complications and quality-of-life (QoL).

MATERIALS & METHODS

This was a retrospective cohort analysis of a prospectively maintained surgical database. Patients who underwent PE for LARC or LRRC cancer with bladder involvement between 1998 and 2021 were included. Post-operative complications and overall survival were compared between patients with PC and RC.

RESULTS

60 PC patients and 269 RC patients were included. Overall R0 resection was 84.3%. Patients with LRRC and PC had poorest oncological outcome with 69% R0 resection; patients with LARC and PC demonstrated highest R0 rate of 96.3% (P = 0.008). Overall, 1-, 3- and 5-year OS was 90.8%, 68.1% and 58.6% after PC, and 88.7%, 62.2% and 49.5% after RC. Rates of urinary sepsis or urological leaks did not differ between groups, however, RC patients experienced significantly higher rates of perineal wound- and flap-related complications (39.8% vs 25.0%, P = 0.032).

CONCLUSION

PC as part of PE can be performed safely with good oncological outcome in patients with LARC. In patients with LRRC, PC results in poor oncological outcome and a more aggressive surgical approach with RC seems justified. The main benefit of PC is a reduction in wound related complications compared to RC, although more urological re-interventions are observed in this group.

Adjuvant chemotherapy and survival outcomes in rectal cancer patients with good response (ypT0-2N0) after neoadjuvant chemoradiotherapy and surgery: A retrospective nationwide analysis

Background

For rectal cancer, it remains unclear how to incorporate tumor response to neoadjuvant chemoradiotherapy (nCRT) when deciding whether to give adjuvant chemotherapy. In this study, we aim to determinate the survival benefit of adjuvant chemotherapy for rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Methods

The study cohort included 720 rectal cancer patients who had good response (ypT0-2N0) after nCRT and surgery, who did or did not receive adjuvant chemotherapy between January 2007 and December 2017, from the Taiwan Cancer Registry and National Health Insurance Research database. The Kaplan-Meier method, log-rank tests, and Cox regression analysis were performed to investigate the effect of adjuvant chemotherapy on 5-year overall survival (OS) and disease-free survival (DFS).

Results

Of 720 patients, 368 (51.1%) received adjuvant chemotherapy and 352 (48.9%) did not. Patients who received adjuvant chemotherapy were more likely to be female, younger (≤ 65), with advanced clinical T (3-4)/N (1-2) classification and ypT2 classification. No significant difference in 5-year OS (p=0.681) or DFS (p=0.942) were observed by receipt of adjuvant chemotherapy or not. Multivariable analysis revealed adjuvant chemotherapy was not associated with better OS (adjusted hazard ratio [aHR], 1.03; 95% Confidence Interval [CI], 0.88-1.21) or DFS (aHR, 1.05; 95% CI, 0.89-1.24). Stratified analysis for OS and DFS found no significant protective effect in the use of adjuvant chemotherapy, even for those with advanced clinical T or N classification.

Conclusion

Adjuvant chemotherapy may be omitted in rectal cancer patients with good response (ypT0-2N0) after nCRT and surgery.

Quantitative assessment of the microstructure of the mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighed magnetic resonance imaging

BACKGROUND

The mesorectum surrounding the rectum provides an ideal substrate for tumour spread. However, preoperative risk assessment is still an issue. This study aimed to investigate the microstructural features of mesorectum with different prognostic statuses by intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI).

METHODS

Patients with pathologically proven rectal adenocarcinoma underwent routine high-resolution rectal magnetic resonance imaging (MRI) and IVIM DWI sequences were acquired. The MRI-detected circumferential resection margin (mrCRM) and extramural vascular invasion (mrEMVI) were evaluated. IVIM parameters of the mesorectum adjacent to (MAT) and distant from (MDT) the tumour were measured and compared between and within the prognostic factor groups.

RESULTS

The positive mrCRM (pMAT < 0.001; pMDT = 0.013) and mrEMVI (pMAT = 0.001; pMDT < 0.001) groups demonstrated higher D values in the MAT and MDT than the corresponding negative groups. Conversely, the positive mrCRM (p = 0.001) and mrEMVI (p < 0.001) groups both demonstrated lower f values in the MAT. Similarly, in the self-comparison between the MAT and MDT in the above subgroups, D showed a significant difference in all subgroups (p < 0.001 for all), and f showed a significant difference in the positive mrCRM (p = 0.001) and mrEMVI (p = 0.002) groups. Moreover, the MAT displayed a higher D* in the positive mrCRM (p = 0.014), negative mrCRM (p = 0.009) and negative mrEMVI groups (p < 0.001).

CONCLUSION

The microstructure of the mesorectum in patients with rectal cancer with poor prognostic status shows changes based on IVIM parameters. IVIM parameters might be promising imaging biomarkers for risk assessment of tumour spread in mesorectum preoperatively.

Can CT Pelvimetry Be Used to Predict Circumferential Resection Margin Positivity in Laparoscopic Resection of Middle and Lower Rectum Cancer?

Background Previous studies have shown that pelvimetry can be valuable in predicting surgical difficulties in rectal cancer operations. However, its usability in predicting circumferential resection margin (CRM) involvement remains debatable. This study investigated the factors affecting CRM status and the importance of computed tomography (CT) pelvimetry in predicting CRM involvement in laparoscopic resection of middle and lower rectal cancer. Methodology In this study, we retrospectively investigated the data of 111 patients who underwent a laparoscopic operation for middle and lower rectum cancer at Ankara University Faculty of Medicine, Department of Surgical Oncology between January 2014 and January 2020. The predictive value of CT pelvimetry and other variables on the CRM status was analyzed. Results The following four pelvic parameters differed significantly between the genders: transverse diameter of the pelvic inlet (p = 0.024), anteroposterior diameter of the pelvic outlet (p = 0.003), transverse diameter of the pelvic outlet (p < 0.001), and pelvic depth (p < 0.001). The effect of pelvic anatomic parameters on CRM involvement was not found to be significant. It was found that tumor height from the anal verge (p = 0.004), tumor size (p < 0.001), and gender (p = 0.033) were significant risk factors for CRM involvement. Survival was poor in patients with male gender (p = 0.032), perineural invasion (p < 0.001), and grade 3 tumor. Conclusions In this study, no benefit was found in predicting CRM positivity from CT pelvimetry in the laparoscopic resection of middle and lower rectal cancer. Besides, tumor height from the anal verge, tumor size, and gender were important factors for CRM positivity. Although our study sheds light on this issue, prospective randomized studies with larger sample sizes are needed.

Patterns and predictors of recurrence after laparoscopic resection of rectal cancer

Purpose

This study was designed to evaluate the patterns and predictors of recurrence in patients who underwent laparoscopic resection of rectal cancer.

Methods

Patients with rectal cancer receiving laparoscopic resection between April 2009 and March 2016 were retrospectively analyzed. The association of recurrence with clinicopathological characteristics was evaluated using multivariate analyses.

Results

A total of 405 consecutive patients were included in our study. Within a median follow-up time of 62 months, 77 patients (19.0%) experienced disease recurrence: 10 (2.5%) had locoregional recurrence (LR), 61 (15.1%) had distant metastasis (DM), and 6 (1.5%) developed LR and DM synchronously. The lung was the most common site of metastasis. Multivariate analyses indicated that involved circumferential resection margin (CRM) was the only independent predictor for LR (OR=13.708, 95% CI 3.478-54.026, P&lt;0.001), whereas elevated baseline level of CA19-9 (OR=3.299, 95% CI 1.461-7.449, P=0.032), advanced pN stage (OR=2.292, 95% CI 1.177-4.462, P=0.015) and harvested lymph nodes less than 12 (OR=2.418, 95% CI 1.245-4.695, P=0.009) were independently associated with DM. Patients receiving salvage surgery showed superior 3-year survival compared with palliative treatment after relapse (90.9% vs. 20.5%; P=0.017). The estimated 5-year DFS and CSS for the entire cohort was 80.2% and 83.1%, respectively.

Conclusions

DM was more common than LR after laparoscopic resection of rectal cancer, and there were several clinicopathological factors related to LR and DM. Involved CRM and suboptimal lymph node yield were adverse surgery-related factors of tumor recurrence, which should be paid more attention to during the operation.

Three-year outcomes of transanal total mesorectal excision versus standard laparoscopic total mesorectal excision for mid and low rectal cancer

INTRODUCTION

Since transanal total mesorectal excision (taTME) was introduced, it has become an important topic in rectal cancer treatment. Many previous studies reported positive relevant short-term results, histopathological results, and associated complications. Recently, concerns regarding the oncological safety of taTME have been raised due to reports showing high local recurrences (LR) rates. Therefore, this study aimed to compare the 3-year outcomes between taTME and laparoscopic total mesorectal excision (laTME) for mid-low rectal cancer.

METHODS

A total of 104 patients who underwent taTME were matched with 208 patients treated by laTME. The primary endpoint was 3-year LR rate; secondary endpoints in this matched-cohort study included the perioperative outcomes and histopathological outcomes.

RESULTS

taTME was associated with lower permanent ostomy rate (1% vs 13.5%) and lower conversion rate (0% vs 3.4%) compared to laTME. A similar quality of resected specimens was detected for each group. In both groups, the local recurrence rate was 3.8%. Within 3 years after surgery, the disease-free survival (DFS) rates were 78.8% in the taTME group and 76.9% in the laTME group (P = 0.640), while the overall survival (OS) rates were 93.3% in the taTME group and 89.9% in the laTME group (P = 0.327).

CONCLUSION

No significant differences regarding 3-year local recurrence rate (3.8%) were observed in the taTME group compared to laTME group.

Transanal total mesorectal excision for abdominoperineal resection is associated with poor oncological outcomes in rectal cancer patients: A word of caution from a multicentric Canadian cohort study

AIM

The main objective of this study was to compare the oncological outcomes of patients undergoing abdominoperineal resection (APR) versus low anterior resection (LAR) through a transanal total mesorectal excision (taTME) approach.

METHOD

A total of 360 adult patients with a diagnosis of rectal cancer were enrolled at participating centres from the Canadian taTME Expert Collaboration. Forty-three patients received taTME-APR and received 317 taTME-LAR. Demographic, operative, pathological and follow-up data were collected and merged into a single database. Results are presented as hazard ratio (HR) and 95% confidence interval. All analyses were performed in the R environment (v.3.6).

RESULTS

The proportion of patients with a positive circumferential radial margin status was higher in the taTME-APR group than the taTME-LAR group (21% vs. 9%, p = 0.001). Complete TME was achieved in 91% of those undergoing APR compared with 96% of those undergoing LAR (p = 0.25). APR was associated with a greater rate of local recurrence relative to LAR, although it was not significant [crude HR = 3.53 (95% CI 0.92-13.53)]. Circumferential margin positivity was significantly associated with a higher rate of systemic recurrence [crude HR = 3.59 (95% CI 1.38-9.3)].

CONCLUSION

Our results demonstrate inferior outcomes in those undergoing taTME-APR compared with taTME-LAR. The use of this technique for this particular indication needs to be carefully considered.

MRI at Restaging After Neoadjuvant Therapy for Rectal Cancer Overestimates Circumferential Resection Margin Proximity as Determined by Comparison With Whole-Mount Pathology

BACKGROUND

Current guidelines recommend restaging with MRI after neoadjuvant therapy for rectal cancer, but the accuracy of restaging MRI in estimating circumferential margin involvement requires additional clarification.

OBJECTIVE

The objective of this study was to measure the accuracy of circumferential resection margin assessment by MRI after neoadjuvant therapy and identify characteristics associated with accuracy.

DESIGN

MRI data were retrospectively analyzed for concordance with the findings of whole-mount pathology analysis of the corresponding surgical specimens. Univariate and multivariate logistic regression analyses were performed to identify characteristics associated with accuracy.

SETTING

This study was conducted at a comprehensive cancer center.

PATIENTS

Included in the study were consecutive patients who underwent total mesorectal excision for rectal cancer between January 2018 and March 2020 after receiving neoadjuvant therapy and undergoing restaging with MRI.

MAIN OUTCOME MEASURES

The primary outcome of this study included accuracy, sensitivity, specificity, and positive and negative predictive values for categorizing the circumferential resection margin as threatened; mean and paired mean differences were in proximity of the margin.

RESULTS

Of the 94 patients included in the analysis, 39 (41%) had a threatened circumferential resection margin according to MRI at restaging, but only 17 (18%) had a threatened margin based on pathology. The accuracy of MRI in identifying a threatened margin was 63.8%, with margin proximity overestimated by 0.4 cm on average. In multivariate logistic regression, anterior location of the margin and tumor proximity to the anal verge were independently associated with reduced MRI accuracy.

LIMITATIONS

A limitation was the retrospective design at a single institution.

CONCLUSIONS

The knowledge that MRI-based restaging after neoadjuvant therapy overestimates circumferential margin proximity may render some surgical radicality unnecessary and thereby help avoid the associated morbidity. With the recognition that MRI-based assessment of margin proximity may not be reliable for anterior margin and for distal tumors, radiologists may want to use greater caution in interpreting images of tumors with these characteristics and to acknowledge the uncertainty in their reports. See Video Abstract at http://links.lww.com/DCR/B814.

LA IRM EN LA REESTADIFICACIN LUEGO DE TERAPIA NEOADYUVANTE EN EL CNCER DE RECTO SOBRESTIMA LA PROXIMIDAD DEL MARGEN DE RESECCIN CIRCUNFERENCIAL SEGN LO DETERMINADO COMPARATIVAMENTE CON LA PIEZA DE ANATOMOPATOLOGA

ANTECEDENTES:Las pautas actuales recomiendan la re-estadificación por medio de la resonancia magnética luego de terapia neoadyuvante en los casos de cáncer de recto, pero la precisión de la reevaluación con la IRM para estimar el grado de implicación del margen circunferencial requiere aclaraciones adicionales.OBJETIVO:Medir el grado de exactitud en la evaluación del margen de resección circunferencial mediante resonancia magnética después de la terapia neoadyuvante e identificar las características asociadas con la precisión.DISEÑO:Se analizaron retrospectivamente los datos de resonancia magnética para determinar la concordancia entre los hallazgos del análisis de la pieza de anatamopatología y las muestras quirúrgicas correspondientes. Se realizó el análisis de regresión logística univariada y multivariada para identificar las características asociadas con la exactitud.AJUSTE:Centro oncológico integral.PACIENTES:Todos aquellos que se sometieron consecutivamente a una excisión total del mesorrecto por cáncer rectal entre Enero 2018 y Febrero 2020 luego de recibir terapia neoadyuvante y someterse a una re-estadificación por imágenes de resonancia magnética (IRM).PRINCIPALES MEDIDAS DE RESULTADO:La exactitud, la sensibilidad y especificidad; los valores predictivos positivos y negativos para categorizar el margen de resección circunferencial como amenazado; la diferencia media y las medias pareadas de proximidad a los margenes.RESULTADOS:De los 94 pacientes incluidos en el análisis, 39 (41%) tenían un margen de resección circunferencial amenazado según la resonancia magnética en la re-estadificación, pero solo 17 (18%) tenían un margen amenazado basado en la patología. La precisión de la resonancia magnética para identificar un margen amenazado fue del 63,8%, con la proximidad del margen sobreestimada en 0,4 cm en promedio. En la regresión logística multivariada, la ubicación anterior de los bordes de resección y la proximidad del tumor al margen anal se asociaron de forma independiente con la reducción en la precisión de la resonancia magnética.LIMITACIONES:Diseño retrospectivo en una institución única.CONCLUSIONES:El saber que la re-estadificación basada en la IRM, luego de terapia neoadyuvante sobreestima la proximidad de la lesión a los márgenes circunferenciales, hace innecesaria cierta radicalidad quirúrgica complementaria, lo que ayuda a evitar morbilidad asociada. Reconociendo que la evaluación de proximidad de los márgenes de resección basada en la resonancia magnética, no puede ser confiable en casos de márgenes anteriores y en casos de tumores distales. Los radiólogos recomiendan tener más precaución en la interpretación de imágenes de tumores con estas características y reconocen cierto desasosiego en sus informes. Consulte Video Resumen en http://links.lww.com/DCR/B814.

Shrinkage versus fragmentation response in neoadjuvantly treated oesophageal adenocarcinoma: significant prognostic relevance

Aims

No consensus exists on the clinical value of tumour regression grading (TRG) systems for therapy effects of neoadjuvant chemoradiotherapy (nCRT) in oesophageal adenocarcinoma. Existing TRG systems lack standardization and reproducibility, and do not consider the morphological heterogeneity of tumour response. Therefore, we aim to identify morphological tumour regression patterns of oesophageal adenocarcinoma after nCRT and their association with survival.

Methods and results

Patients with oesophageal adenocarcinoma, who underwent nCRT followed by surgery and achieved a partial response to nCRT, were identified from two Dutch upper‐gastrointestinal (GI) centres (2005–18; test cohort). Resection specimens were scored for regression patterns by two independent observers according to a pre‐defined three‐step flowchart. The results were validated in an external cohort (2001–17). In total, 110 patients were included in the test cohort and 115 in the validation cohort. In the test cohort, two major regression patterns were identified: fragmentation (60%) and shrinkage (40%), with an excellent interobserver agreement (κ = 0.87). Here, patients with a fragmented pattern had a significantly higher pathological stage (stages III/IV: 52 versus 16%; P < 0.001), less downstaging (48 versus 91%; P < 0.001), a higher risk of recurrence [risk ratio (RR) = 2.9, 95% confidence interval (CI) = 1.5–5.6] and poorer 5‐year overall survival (30 versus 80% respectively, P = 0.001).

Conclusions

The validation cohort confirmed these findings, although had more advanced cases (case‐stages = III/IV 91 versus 73%, P = 0.005) and a higher prevalence of fragmented‐pattern cases (80 versus 60%, P = 0.002). When combining the cohorts in multivariate analysis, the pattern of response was an independent prognostic factor [hazard ratio (HR) = 1.76, 95% CI = 1.0–3.0]. In conclusion, we established an externally validated, reproducible and clinically relevant classification of tumour response.

MRI for Rectal Cancer: Staging, mrCRM, EMVI, Lymph Node Staging and Post-Treatment Response

Rectal cancer is a relatively common malignancy in the United States. Magnetic resonance imaging (MRI) of rectal cancer has evolved tremendously in recent years, and has become a key component of baseline staging and treatment planning. In addition to assessing the primary tumor and locoregional lymph nodes, rectal MRI can be used to help with risk stratification by identifying high-risk features such as extramural vascular invasion and can assess treatment response for patients receiving neoadjuvant therapy. As the practice of rectal MRI continues to expand further into academic centers and private practices, standard MRI protocols, and reporting are critical. In addition, it is imperative that the radiologists reading these cases work closely with surgeons, medical oncologists, radiation oncologists, and pathologists to ensure we are providing the best possible care to patients. This review aims to provide a broad overview of the role of MRI for rectal cancer.

Pathological Features and Prognostication in Colorectal Cancer

The prognostication of colorectal cancer (CRC) has traditionally relied on staging as defined by the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications. However, clinically, there appears to be differences in survival patterns independent of stage, suggesting a complex interaction of stage, pathological features, and biomarkers playing a role in guiding prognosis, risk stratification, and guiding neoadjuvant and adjuvant therapies. Histological features such as tumour budding, perineural invasion, apical lymph node involvement, lymph node yield, lymph node ratio, and molecular features such as MSI, KRAS, BRAF, and CDX2 may assist in prognostication and optimising adjuvant treatment. This study provides a comprehensive review of the pathological features and biomarkers that are important in the prognostication and treatment of CRC. We review the importance of pathological features and biomarkers that may be important in colorectal cancer based on the current evidence in the literature.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Impact of nutritional status and body composition on postoperative outcomes after pelvic exenteration for locally advanced and locally recurrent rectal cancer

Background

Pelvic exenteration for locally advanced rectal cancer (LARC) and locally recurrent (LRRC) rectal cancer provides radical resection and local control, but is associated with considerable morbidity. The aim of this study was to determine risk factors, including nutritional status and body composition, for postoperative morbidity and survival after pelvic exenteration in patients with LARC or LRRC.

Methods

Patients with LARC or LRRC who underwent total or posterior pelvic exenteration in a tertiary referral centre from 2003 to 2018 were analysed retrospectively. Nutritional status was assessed using the Malnutrition Universal Screening Tool (MUST). Body composition was estimated using standard-of-care preoperative CT of the abdomen. Logistic regression analyses were performed to identify risk factors for complications with a Clavien–Dindo grade of III or higher. Risk factors for impaired overall survival were calculated using Cox proportional hazards analysis.

Results

In total, 227 patients who underwent total (111) or posterior (116) pelvic exenteration were analysed. Major complications (Clavien–Dindo grade at least III) occurred in 82 patients (36.1 per cent). High risk of malnutrition (MUST score 2 or higher) was the only risk factor for major complications (odds ratio 3.99, 95 per cent c.i. 1.76 to 9.02) in multivariable analysis. Mean follow-up was 44.6 months. LRRC (hazard ratio (HR) 1.61, 95 per cent c.i. 1.04 to 2.48) and lymphovascular invasion (HR 2.20, 1.38 to 3.51) were independent risk factors for impaired overall survival.

Conclusion

A high risk of malnutrition according to the MUST is a strong risk factor for major complications in patients with LARC or LRRC undergoing exenteration surgery.

Survival Impact of Chronic Obstructive Pulmonary Disease or Acute Exacerbation on Patients with Rectal Adenocarcinoma Undergoing Curative Resection: A Propensity Score-Matched, Nationwide, Population-Based Cohort Study

PURPOSE

The survival effect of current smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with rectal adenocarcinoma undergoing curative resection.

METHODS

We recruited patients with clinical stage I-IIIC rectal adenocarcinoma from the Taiwan Cancer Registry Database who had received surgery. The Cox proportional hazards model was used to analyze all-cause mortality. We categorized the patients into two groups by using propensity score matching based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD).

RESULTS

In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.25 (1.04-1.51). The aHRs (95% cis) of all-cause mortality for frequency of ≥1 hospitalizations for COPDAE or ≥2 hospitalizations within 1 year before diagnosis were 1.17 (1.05-1.51) and 1.48 (1.03-2.41) compared with no COPDAE in patients with rectal adenocarcinoma undergoing curative resection.

CONCLUSION

In patients with rectal adenocarcinoma undergoing curative resection, being a current smoker with COPD (Group 1) was associated with worse survival outcomes than being a nonsmoker without COPD (Group 2). Being hospitalized at least once for COPDAE within 1 year before the diagnosis of rectal adenocarcinoma is an independent risk factor for poor overall survival in these patients, and a higher number of hospitalizations for COPDAE within 1 year before diagnosis was associated with poorer survival.

Relation between body composition and severe diarrhea in patients treated with preoperative chemoradiation with capecitabine for rectal cancer: a single-centre cohort study

Background

Chemoradiation with capecitabine followed by surgery is standard care for locally advanced rectal cancer (LARC). Severe diarrhea is considered a dose-limiting toxicity of adding capecitabine to radiation therapy. The aim of this study was to describe the risk factors and the impact of body composition on severe diarrhea in patients with LARC during preoperative chemoradiation with capecitabine.

Methods

A single centre retrospective cohort study was conducted in a tertiary referral centre. All patients treated with preoperative chemoradiation with capecitabine for LARC from 2009 to 2015 were included. Patients with locally recurrent rectal cancer who received chemoradiation for the first time were included as well. Logistic regression analyses were performed to identify risk factors for severe diarrhea.

Results

A total of 746 patients were included. Median age was 64 years (interquartile range 57–71) and 477 patients (64%) were male. All patients received a radiation dosage of 25 × 2 Gy during a period of five weeks with either concomitant capecitabine administered on radiation days or continuously during radiotherapy. In this cohort 70 patients (9%) developed severe diarrhea. In multivariable logistic regression analyses female sex (OR: 4.42, 95% CI 2.54–7.91) and age ≥ 65 (OR: 3.25, 95% CI 1.85–5.87) were the only risk factors for severe diarrhea.

Conclusions

Female patients and patients aged sixty-five or older had an increased risk of developing severe diarrhea during preoperative chemoradiation therapy with capecitabine. No relation was found between body composition and severe diarrhea.

Four-Tier Pathologic Tumor Regression Grading System Predicts the Clinical Outcome in Patients Who Undergo Surgical Resection for Locally Advanced Pancreatic Cancer after Neoadjuvant Chemotherapy

Background/Aims

Neoadjuvant chemotherapy is increasingly utilized in patients with borderline or locally advanced pancreatic cancer (LAPC). However, the pathologic evaluation of tumor regression is not routinely performed or well established. We aimed to evaluate the prognostic value of three tumor regression grading systems frequently used in LAPC and to determine the correlation between pathologic and clinical response.

Methods

We included a total of 38 patients with LAPC who were treated with neoadjuvant chemotherapy and subsequent resection. Pathologic tumor regression was graded based on the College of American Pathologists (CAP), Evans, and MD Anderson grading systems.

Results

One out of 38 patients (2.6%) achieved a pathologic complete response. Unlike other grading systems (Evans, p=0.063; MD Anderson, p=0.110), the CAP grading system was a significant prognostic factor for overall survival (p=0.043). Pathologic N stage (p=0.023), margin status (p=0.044), and radiologic response (p=0.016) correlated with overall survival. In the multivariate analysis, CAP 3 was an independent predictor of shorter overall survival (p=0.026). The CAP grading system correlated with the radiologic response (p=0.007) but not the carbohydrate antigen 19-9 level (p=0.333).

Conclusions

The four-tier CAP pathologic tumor regression grading system predicted the clinical outcome in LAPC patients who underwent resection after neoadjuvant chemotherapy. Therefore, a more comprehensive pathologic evaluation is warranted in these patients.

Persistent High Rate of Positive Margins and Postoperative Complications After Surgery for cT4 Rectal Cancer at a National Level

BACKGROUND

A more extensive resection is often required in locally advanced rectal cancer, depending on preoperative neoadjuvant treatment response.

OBJECTIVE

Circumferential margin involvement and postoperative outcomes after total mesorectal excision and multivisceral resection were assessed in patients with clinical locally advanced (cT4) rectal cancer at a national level.

DESIGN

This is a population-based study.

SETTINGS

Data were retrieved from the Dutch Colorectal Audit.

PATIENTS

A total of 2242 of 2881 patients with cT4 rectal cancer between January 2009 and December 2017 were selected.

MAIN OUTCOME MEASURES

Main outcomes were resection margins, postoperative complications, and mortality.

RESULTS

Multivisceral resection was performed in 936 of 2242 patients, of whom 629 underwent extended multivisceral resection. Positive circumferential margin rate was higher after multivisceral resection than after total mesorectal excision: 21.2% vs 13.9% (p < 0.001). More postoperative complications occurred after limited and extended multivisceral resections than after total mesorectal excision (44.1% and 53.8% vs 37.6%, p < 0.001). Incidence of 30-day mortality was similarly low in both groups (1.5% vs 2.2%, p = 0.20). Independent predictors of postoperative complications were age ≥70 years (OR, 1.28 [95% CI, 1.04-1.56]; p = 0.02), male sex (OR, 1.68 [95% CI, 1.38-2.04]; p< 0.001), mucinous tumors (OR, 1.55 [95% CI, 1.06-2.27]; p = 0.02), extended multivisceral resection (OR, 1.98 [95% CI, 1.56-2.52]; p< 0.001), Hartmann procedure (OR, 1.42 [95% CI, 1.07-1.90]; p = 0.02), and abdominoperineal resection (OR, 1.56 [95% CI, 1.25-1.96]; p < 0.001).

LIMITATIONS

Data specifying the extent of multivisceral resections and Clavien Dindo I to II complications were not available.

CONCLUSIONS

This population-based study revealed relatively high circumferential margin positivity and postoperative complication rates in patients with cT4 rectal cancer, especially after multivisceral resections, but low mortality rates. See Video Abstract at http://links.lww.com/DCR/B457.

ALTA TASA PERSISTENTE DE MRGENES POSITIVOS Y COMPLICACIONES POSTOPERATORIAS DESPUS DE LA CIRUGA DE CNCER RECTAL CTA NIVEL NACIONAL

ANTECEDENTES:A menudo se requiere una resección más extensa en el cáncer de recto localmente avanzado, según la respuesta al tratamiento neoadyuvante preoperatorio.OBJETIVO:Se evaluó la afectación del margen circunferencial y los resultados postoperatorios después de la escisión mesorrectal total y la resección multivisceral en pacientes con cáncer rectal clínico localmente avanzado (cT4) a nivel nacional.DISEÑO:Este es un estudio poblacional.ENTORNO CLINICO:Los datos se recuperaron de la Auditoría colorrectal holandesa.PACIENTES:Se seleccionaron un total de 2242 de 2881 pacientes con cáncer de recto cT4 entre enero de 2009 y diciembre de 2017.PRINCIPALES MEDIDAS DE VALORACION:Los principales resultados fueron los márgenes de resección, las complicaciones postoperatorias y la mortalidad.RESULTADOS:Se realizó resección multivisceral en 936 de 2242 pacientes, de los cuales 629 fueron sometidos a resección multivisceral extendida. La tasa de margen circunferencial positivo fue mayor después de la resección multivisceral que después de la escisión mesorrectal total: 21,2% versus a 13,9% (p <0,001). Se produjeron más complicaciones postoperatorias después de resecciones multiviscerales limitadas y extendidas en comparación con la escisión mesorrectal total (44,1% y 53,8% versus a 37,6%, p <0,001). La incidencia de mortalidad a 30 días fue igualmente baja en ambos grupos (1,5% versus a 2,2%, p = 0,20). Los predictores independientes de complicaciones posoperatorias fueron la edad ≥70 años (OR = 1,28, IC del 95% [1,04 a 1,56], p = 0,02), hombres (OR = 1,68, IC del 95% [1,38 a 2,04], p <0,001), tumores mucinosos (OR = 1,55, IC del 95% [1,06 a 2,27], p = 0,02), resección multivisceral extendida (OR = 1,98, IC del 95% [1,56 a 2,52], p <0,001), Hartmann (OR = 1,42, 95% Cl [1,07 a 1,90], p = 0,02) y resección abdominoperineal (OR 1,56, Cl 95% [1,25 a 1,96], p <0,001).LIMITACIONES:No se disponía de datos que especificaran el alcance de las resecciones multiviscerales y las complicaciones de Clavien Dindo I-II.CONCLUSIONES:Este estudio poblacional reveló tasas de complicaciones postoperatorias y positividad del margen circunferencial relativamente altas en pacientes con cáncer de recto cT4, especialmente después de resecciones multiviscerales, pero tasas de mortalidad bajas. Consulte Video Resumen en http://links.lww.com/DCR/B457.

Oncological strategy following R1 sphincter-saving resection in low rectal cancer after chemoradiotherapy

AIM

Sphincter-saving resection (SSR) for low rectal cancer remains challenging due to the high risk of positive resection margin (R1). Long-term outcomes and the dedicated oncological strategy are not well established in this situation. The aim of this study was to define the more appropriate strategy according to the patterns of recurrence.

METHODS

Between 1994 and 2014, patients treated by SSR for low rectal cancer with preoperative chemoradiotherapy were included. Three types of recurrences were defined: local (LR), distant (DR) and mixed (MR). Recurrences and survival after R0 and R1 resection were analysed by Kaplan-Meier and compared with the log-rang test.

RESULTS

Among 394 patients receiving SSR, 42 (10.6%) had R1 resection. Independent factors of R1 resection were EMVI (OR2.24,95%IC1.10-4.53,p = 0.025) and no tumor downstaging (OR8.41,95%IC2.50-8.32,p = 0.001). Both 5-year disease free and overall survival, and 5-year distant and local recurrence, were significantly worse after R1 resection. The overall recurrence after R1 resection was 57% (24/42), 7% had LR, 36% DR and 14% MR. Time to DR was shorter than time to LR (11.1 vs. 34.3) months. In all cases of MR, DR occurred before LR (12.1 vs. 34.3) months, meaning that after R1 resection, the first concern was DR.

CONCLUSION

R1 resection after SSR for low rectal cancer reflects a more aggressive and systemic disease. Prognosis depends on DR in about 90% of cases, suggesting that pelvic control should not be the priority in the oncological strategy after R1. Adjuvant systemic chemotherapy ought to be preferred to salvage abdominoperineal resection.

Avoidance of Overtreatment of Rectal Cancer by Selective Chemoradiotherapy: Results of the Optimized Surgery and MRI-Based Multimodal Therapy Trial

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects. The aim of this study was to examine the selective application of nCRT based on patient risk profile, as determined by MRI, to find the optimal range between undertreatment and overtreatment.

STUDY DESIGN

In this prospective multicenter observational study, nCRT before total mesorectal excision (TME) was indicated in high-risk patients with involved or threatened mesorectal fascia (≤1 mm), or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery.

RESULTS

Of the 1,093 patients, 878 (80.3%) were treated according to the protocol, 526 patients (59.9%) underwent primary surgery, and 352 patients (40.1%) underwent nCRT followed by surgery. The 3-year locoregional recurrence (LR) rate was 3.1%. Of 604 patients with clinical stages II and III, 267 (44.2%) had primary surgery; 337 (55.8%) received nCRT followed by TME. The 3-year LR rate was 3.9%, without significant differences between groups. In patients with clinical stages II and III who underwent primary surgery, 27.3% were diagnosed with pathological stage I.

CONCLUSIONS

The results justify the restriction of nCRT to high-risk patients with rectal cancer classified by pretreatment MRI. Provided that a high-quality MRI diagnosis, TME surgery, and standardized examination of the resected specimen are performed, nCRT, with its adverse effects, costs, and treatment time can be avoided in more than 40% of patients with stage II or III rectal cancer with minimal risk of undertreatment. (clinicaltrials.gov NCT325649).

Predictive Significance of Mucinous Histology on Pathologic Complete Response Rate Following Capecitabine-Based Neoadjuvant Chemoradiation in Rectal Cancer: a Comparative Study

INTRODUCTION

Currently, neoadjuvant fluoropyrimidine-based chemoradiation followed by surgery is considered the standard of care for locally advanced rectal cancer. The current study aimed to investigate the predictive significance of mucinous histology on the pathologic complete response rate following neoadjuvant chemoradiation in locally advanced rectal cancer and to propose potential new treatment protocol for this specific histology.

MATERIAL AND METHOD

This retrospective study was conducted on 403 patients with locally advanced (clinically T3-4 and/or N1-2) rectal adenocarcinoma who had been treated at three tertiary academic hospitals between 2010 and 2015. Among those 403 patients, 46 (11%) had mucinous rectal cancer (MRC) and 358 (89%) had non-mucinous rectal cancer (NMRC). All patients underwent neoadjuvant chemoradiation with capecitabine followed by low anterior or abdominoperineal resection.

RESULTS

There were 268 men and 135 women with a median age of 55 years (range, 26-82 years). Patients with MRC were younger (p = 0.002) and presented with a larger tumor size (p < 0.001) and a more advanced tumor stage (p = 0.033) compared to the ones with MNRC. In the univariate analysis, female gender (p = 0.009), distal tumor location (p = 0.035), higher tumor stage (p = 0.049), node positivity (p = 0.001), MRC histology (p = 0.017), and high pretreatment CEA level (p = 0.013) were observed to be predictive of a poor pathologic complete response. However, in the multivariate analysis, tumor stage was the single most predictive factor of response to neoadjuvant chemoradiation.

CONCLUSION

Mucinous adenocarcinoma is a significant predictive factor for poor pathologic complete response to neoadjuvant capecitabine-based chemoradiation in patients with locally advanced rectal cancer. New treatment modality based on biomarkers may be considered in future prospective studies because of MRC poor prognosis. Immunotherapy combined with chemotherapy and/or radiotherapy may be an attractive option because of the tumor microsatellite instability-high status.

Direct intraoperative assessment of total mesorectal excision specimens by expert pathologists in patients with very low rectal cancer prevents unnecessary abdominoperineal resections

PURPOSE

In patients with low rectal cancer, the intraoperative assessment of sufficient distal resection margins can be challenging. The assessment determines whether reconstruction can be performed or whether permanent colostomy is required. The goal of the present study was to evaluate intraoperative assessment of the total mesorectal excision (TME) specimen during an interruption of the operation.

METHODS

The intraoperative strategy of eight patients with low rectal cancer was evaluated. In all cases, intraoperative pathological assessment of the TME specimen by an expert pathologist together with the surgeon was performed. Assessment of the distance of the tumor to the resection margin was measured macroscopically as well as microscopically.

RESULTS

All patients underwent neoadjuvant chemoradiation. The tumor was located at an average 4.8 ± 1.4 cm from the anal verge. In all cases, preoperative MRI revealed mrT3 tumors. The intraoperative assessment showed a median distal resection margin of 10 mm (2-15 mm). In six patients, sufficient margins allowed for reconstruction while in two patients APR was needed. In three patients (37.5%), the pathological assessment changed the operative strategy: In one patient APR could be avoided while two patients required APR instead of the anticipated TME.

CONCLUSION

The intraoperative assessment of the TME specimen by an expert pathologist together with the surgeon is a valuable tool to avoid unnecessary APR or R1 resections. We therefore suggest routine intraoperative pathological assessment in all operations for borderline low rectal cancers.

How to measure tumour response in rectal cancer? An explanation of discrepancies and suggestions for improvement

Various methods categorize tumour response after neoadjuvant therapy, including down-staging and tumour regression grading. Response categories allow comparison of different treatments within clinical trials and predict outcome. A reproducible response categorization could identify subgroups with high or low risk for the most appropriate subsequent treatments, like watch and wait. Lack of standardization and interpretation difficulties currently limit the usability of these approaches. In this review we describe these difficulties for the evaluation of chemoradiation in rectal cancer. An alternative approach of tumour response is based on patterns of residual disease, including fragmentation. We summarise the evidence behind this alternative method of response categorisation, which explains a number of very relevant clinical discrepancies. These issues include differences between downstaging and tumour regression, high local regrowth in advanced tumours during watchful waiting procedures, the importance of resection margins, the limited value of post-treatment biopsies and the relatively poor outcome of patients with a near complete pathological response. Recognition of these patterns of response can allow meaningful development of novel biomarkers in the future.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

Impact of Preoperative Care for Rectal Adenocarcinoma on Pathologic Specimen Quality and Postoperative Morbidity: A NSQIP Analysis

BACKGROUND

Comprehensive and multidisciplinary care are critical in rectal cancer treatment. We sought to determine if completeness of preoperative care was associated with pathologic specimen quality and postoperative morbidity.

STUDY DESIGN

Clinical stage I-III rectal adenocarcinoma patients who underwent elective low anterior resection or abdominoperineal resection were identified from the 2016-2017 American College of Surgeons-National Surgical Quality Improvement Project (ACS-NSQIP) database. The 3 preoperative NSQIP variables (colonoscopy, stoma marking, and neoadjuvant chemoradiation) were used to divide patients into 2 cohorts: complete vs incomplete preoperative care. The primary outcome was a composite higher pathologic specimen quality score (>12 lymph nodes, negative circumferential, and negative distal margins). The secondary outcome was 30-day morbidity. Preoperative characteristics were compared with ANOVAs and chi-square tests. Outcomes measures were evaluated with logistic regression.

RESULTS

We identified 1,125 patients: 591 (52.5%) complete and 534 (47.5%) incomplete. The complete group was younger, had more women, lower-third rectal tumors, clinical stage III disease, and neoadjuvant treatment. The complete group had higher odds of better pathologic specimen quality after adjusting for age, sex, tumor location, stage, and neoadjuvant therapy (adjusted odds ratio [aOR] 1.75, p = 0.001). The complete group had decreased rates of transfusions (odds ratio [OR] 0.47, p < 0.001), postoperative ileus (OR 0.67, p = 0.01), sepsis (OR 0.32, p = 0.01), and readmissions (OR 0.60, p = 0.003). Other complications did not statistically differ between groups.

CONCLUSIONS

Complete preoperative care in rectal adenocarcinoma is associated with higher pathologic specimen quality and reduced postoperative morbidity. This highlights the importance of adherence to guideline-directed care.

Evolving Treatment Options and Future Directions for Locally Advanced Rectal Cancer

Locally advanced rectal cancer can be biologically heterogeneous, but imaging advances have improved clinical assessment of primary tumor and involved lymph nodes in relation to pelvic structures and intended surgical planes. Contemporary treatment for rectal cancer is tailored to the individual patient through multidisciplinary collaboration among diagnosticians, surgeons, medical oncologists, and radiation oncologists to minimize local recurrence and distant metastases. Furthermore, patient preferences and quality of life preservation are becoming more relevant in the decision-making, and upcoming treatment strategies specifically are designed to minimize toxicities and long-term morbidity. Accumulating data have continued to support the use of total neoadjuvant therapy, namely the completion of: (1) multiagent cytotoxic chemotherapy; and (2) pelvic radiation with or without a radiosensitizing agent, before surgery. The total neoadjuvant therapy strategy not only eliminates potentially occult metastases early but also opens up the possibility of nonsurgical management for those who decline or are unfit for surgery. Finally, noncytotoxic agents in combination with established chemotherapy agents along with potentially predictive biomarkers are also being actively investigated to further improve the clinical outcomes of rectal cancer.

Combined Proctectomy and Hepatectomy for Metastatic Rectal Cancer Should be Undertaken with Caution: Results of a National Cohort Study

BACKGROUND

Simultaneous proctectomy and hepatic resection for stage IV rectal cancer remains controversial due to concerns for increased morbidity and mortality. While small series have described simultaneous rectal and hepatic resection, surgical outcomes in a large national cohort have not been described.

METHODS

Overall, 9012 patients with stage IV rectal adenocarcinoma with hepatic metastases were identified in the National Cancer Data Base (2010-2015). Associations between treatment selection, tumor and patient characteristics, 30- and 90-day mortality, and factors predictive of survival after surgery were examined. Logistic regression analyses were used to evaluate associations between tumor/patient characteristics, and selection of combined proctectomy and hepatectomy (C-PH). Kaplan-Meier analysis was used to identify median survival stratified by age and other patient-specific factors.

RESULTS

Among patients included for analysis, 1331 (14.8%) underwent C-PH. Factors associated with lower rates of C-PH included increasing age, Black/Hispanic race, increased Charlson comorbidity score, Medicare/Medicaid/uninsured status, and treatment at a community cancer program. Thirty- and 90-day mortality increased with age (Chi square 11.4, p < 0.005; and Chi square 23.9, p < 0.001, respectively). On multivariate analysis, poorer survival after C-PH was associated with age > 70 years (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.0-2.5, p < 0.001), perineural invasion (HR 1.5, 95% CI 1.2-1.9, p < 0.001), kras mutation (HR 1.5, 95% CI 1.1-2.1, p = 0.006), positive circumferential margin (HR 1.3, 95% CI 1.0-1.7, p = 0.03), and omission of postoperative chemotherapy (HR 1.4, 95% CI 1.1-1.7, p = 0.002).

CONCLUSIONS

C-PH should be utilized with caution in frail, high-risk patients. Such patients may be better served by staged surgical management or nonsurgical therapy.

Urgent surgery in colon cancer has no impact on survival

BACKGROUND AND OBJECTIVES

Despite advances in early detection of colon cancer, a minority of patients still require urgent surgery. Whether such urgent conditions result in poor outcome remains a topic of debate.

METHODS

Using a prospectively maintained database, patients suffering exclusively from colon cancer and receiving either elective or emergent resection between 2001 and 2014 were analyzed with respect to overall, disease-specific, and relative survival using Cox regression and propensity score analyses.

RESULTS

From a total of 877 patients analyzed, 2.7% (24) presented with complications requiring urgent surgery. Propensity-scoring identified strongly biased patient characteristics (0.097 ± 0.069 vs 0.028 ± 0.043; P < 0.001). An unadjusted Cox proportional hazards regression analysis revealed urgent surgery as a statistically significant prognostic factor with an approximately 207% increased risk of mortality (hazard ratio [HR] = 3.07; 95% confidence interval [CI]: 1.62-5.81; P = 0.003). After adjusting the data according to the propensity score analysis, urgent surgery was not associated with a decreased overall (HR = 1.67; 95%CI; 0.84-3.36; P = 0.174), disease-specific (HR = 1.62; 95% CI; 0.81-3.24; P = 0.201) or relative survival (HR = 1.86; 95% CI: 0.92-3.79; P = 0.086).

CONCLUSIONS

After risk-adjustment, using multivariable Cox regression and propensity score analyses, no significant disadvantage could be noted with regard to overall, disease-specific, or relative survival in patients with exclusively colon cancer who received emergent oncological resection.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy?

Background

We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).

Methods

Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.

Results

The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).

Conclusion

CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

The prognostic value of tumor budding in patients who had surgery for rectal cancer with and without neoadjuvant therapy

BACKGROUND

The aim of this study was to investigate the prognostic value of tumor budding (TB) in rectal cancer patients. TB in the specimens of patients who received neoadjuvant chemoradiotherapy was specifically analyzed.

METHODS

This study was conducted on rectal cancer patients treated at Dokuz Eylul University Hospital, Turkey, between January 2000 and June 2010. Prospectively recorded clinicopathological data and the oncological outcomes of patients who received neoadjuvant chemoradiotherapy (CRT) (n = 117) and also patients who did not receive it (n = 113) were analyzed. TB was defined as an isolated single cancer cell or a cluster of cells composed of less than 5 cells of a "budding focus". Budding intensity was scored as follows: none (0), mild (1-5 buds), moderate (6-10 buds), and severe (> 10 buds). Two tumor budding intesity groups were created, TB-1 (none, few) and TB-2 (moderate, severe) for statistical analysis.

RESULTS

The median follow-up time was 40.12 ± 27.5 months. The 5-year overall and disease-free survival (DFS) rates were 66% and 62%, respectively. Multivariate analysis of overall survival in all patients showed that TB intensity (HR 2.64; 95% CI 1.46-4.77) and radial margin status (HR 2.16; 95% CI 1.18-3.96) were independent predictors of decreased overall survival. In patients who received CRT, TB (HR 4.87; 95% CI 2.10-11.28) and distant metastasis (HR 4.31; 95% CI 1.81-10.22) were predictive of survival while in patients who did not receive CRT, TB (HR 4.28; 95% CI 1.60-11.49), distant metastasis (HR 2.33; 95% CI 1.19-4.60), radial margin status (HR 2.53; 95% CI 1.09-5.91), and venous invasion (HR 4.48; 95% CI 2.14-9.39) were significantly independent predictors of survival. In multivariate analysis of all patients decreased DFS was correlated with lymph node involvement (HR 2.78; 95% CI 1.60-4.87), venous invasion (HR 1.76; 95% CI 1.00-3.09), and with radial margin status (HR 2.31; 95% CI 1.27-4.22). In multivariate analysis in the CRT group, decreased DFS was significantly associated with lymph node involvement (HR 4.39; 95% CI 1.70-11.33) and radial margin status (HR 2.56; 95% CI 1.12-5.90) while only lymph node involvement (HR 2.33; 95% CI 1.16-4.66) was a significant predictor of decreased DFS in patients who did not receive CRT.

CONCLUSIONS

TB has prognostic value as important as lymph node involvement and radial margin status and it may be a helpful prognostic indicator even after CRT. TB should be included in the TNM classification and may be used in planning adjuvant therapy.

[R1 resection in rectal cancer]

R1 resections in rectal cancer particularly affect the circumferential resection margin (CRM) and lead to increased local recurrence rates, more distant metastases and a poorer prognosis. The proximity of the tumor to the CRM is already sufficient to increases these risks; therefore, according to the guidelines, it is now necessary to distinguish between R0 wide (≥1 mm distance), R0 close (<1 mm) and R1. The surgical technique is decisive for avoiding R1 situations. The preparation follows the boundary layers and envelope fascia in a standardized radical way and if necessary deviates away from these structures and the tumor under en bloc resection of neighboring structures. Neoadjuvant therapy also contributes to the reduction of R1 situations but cannot compensate for inadequate surgical procedures.

Comparison of the short-term outcomes in lower rectal cancer using three different surgical techniques: Transanal total mesorectal excision (TME), laparoscopic TME, and open TME

BACKGROUND

Total mesorectal excision (TME) is the standard surgical principle in the treatment of rectal cancer. However, in recent years, there has been an increasing debate about how to obtain better results in circumferential margin (CRM) and distal margins of the surgical specimen. The CRM and distal margin involvement rates have been linked to local recurrence and disease-free survival rates. In this study, we compared three surgical techniques for the treatment of lower rectal cancer.

METHODS

From July 2008 to April 2018, we identified consecutive patients with lower rectal cancer who underwent TME. According to the surgical technique, we divided the patients into three groups: transanal TME (TaTME), laparoscopic TME (LaTME), and open TME (OpTME).

RESULTS

A total of 126 patients underwent TME; 39, 64 and 23 patients underwent TaTME, LaTME, and OpTME respectively. Tumor location was lower in the TaTME group than the other groups (p < 0.01). TaTME resulted in longer operation time than the other two groups (p < 0.01). In pathological outcomes, no patients with a CRM <1 mm were observed in the TaTME group compared with five (7.8%) and three patients (13.0%) with CRM <1 mm in the LaTME and OpTME group respectively (p = 0.035). Patients in the TaTME and LaTME groups also had a better disease-free survival than OpTME group (p < 0.01).

CONCLUSION

TaTME provides surgeons with a novel and effective method to treat lower rectal cancer. In the short-term outcomes, TaTME achieved better pathological results and disease free survival than OpTME but not significantly superior to LaTME. Further studies are necessary to evaluate the long-term oncological results.

Prognostic impact of anastomotic leakage after elective colon resection for cancer - A propensity score matched analysis of 628 patients

BACKGROUND

There is limited information regarding the impact of anastomotic leakage on oncologic outcome in exclusively colon cancer patients.

METHODS

The colorectal database of the Department of Surgery of the University of Heidelberg was used to assess the impact of anastomotic leakage on oncologic outcome in patients undergoing curative resection for Stage I-III colon cancer. Risk-adjusted Cox regression analysis and propensity score methods were used to assess overall, disease-free, and relative survival.

RESULTS

628 patients of which 26 (4.1%) experienced anastomotic leakage were analysed. Anastomotic leakage was associated with significantly worse overall, disease-free and relative survival in univariate and multivariate analysis. The analysis after exact propensity score matching confirmed the negative impact of anastomotic leakage on overall (HR 2.62, 95% CI 1.33-5.18, p = .011), disease-free (HR 2.28, 95% CI 1.16-4.47, p = .027) and relative survival (HR 3.70, 95% CI 1.82-7.52, p < .001). 5-year overall survival was 51.6% (95% CI 34.5-77.2%) for patients with anastomotic leakage compared to 77.7% (95% CI 73.0-82.8%) for patients without anastomotic leakage.

CONCLUSIONS

All conceivable efforts should be made to avoid anastomotic leakage after colon resection for cancer not only to evade short-term consequences but also to allow for adequate long-term outcome.

A Prospective Study of Distal Microscopic Spread in Rectal Cancer After Neoadjuvant Chemoradiation in Pinned and Unpinned Specimen

The most important margin in determining the prognosis of rectal cancer is circumferential resection margin (CRM). But, the type of surgery is determined by distal rectal margin (DRM), whether sphincter saving procedure is possible or patient needs an abdominoperineal resection. There are no standardized uniform guidelines for measurement of DRM. The purpose of this study is to assess the distal microscopic spread beyond gross margin after neoadjuvant concurrent chemoradiation (CCRT) in rectal cancers, the factors influencing the distal microscopic spread, the shrinkage of the distal margin in pinned and unpinned fresh and fixed specimen, and to find out the best method of measurement of distal rectal margin. A prospective analytical study was conducted from May 2013 through February 2015 in 47 cases of carcinoma rectum (both AR and APR) who had received neoadjuvant CCRT. Fresh specimen was collected within 30 min of specimen retrieval and a longitudinal cut was made in the distal margin of all specimens. One side of the specimen was pinned onto a cork board and the other side was left unpinned. Measurements were made from the distal end of clinical gross tumor. DRM was determined in both pinned and unpinned sides in fresh and fixed specimen. Of the 47 patients, 2 patients (4.2%) had small focus of tumor beyond gross margins, 1 at 6 mm and another at 3.5 mm on the unpinned side. The average margin for fresh and fixed pinned specimens was 3.67 and 3.47 cm, respectively, with percentage shrinkage of 5.4% for the pinned specimens. The average margin for fresh and fixed unpinned specimens was 3.32 and 2.84 cm, respectively, with percentage shrinkage of 14.4% for the unpinned specimens. Six patients (12.7%) had complete pathological response. Correlation of distal margin was better in pinned specimen. A correction factor of 15% for shrinkage needs to be taken into account while assessing unpinned specimen. Only in 4.2% of patients, there was distal submucosal spread beyond gross margin. Long-term follow up is required for assessing adequacy of DRM post neoadjuvant CCRT.

Monitoring neoadjuvant therapy responses in rectal cancer using multimodal nonlinear optical microscopy

Most patients with rectal cancer have a better prognosis after receiving neoadjuvant therapy because of its remarkable curative effect. However, no device delivers real-time histopathologic information on treatment response to help clinicians tailor individual therapeutic strategies. We assessed the potential of multimodal nonlinear optical microscopy to monitor therapeutic responses, including tumoral and stromal responses. We found that two-photon excited fluorescence imaging can, without labeling, identify colloid response, inflammatory cell infiltration, vascular proliferation, and tumor regression. It can also directly detect rare residual tumor cells, which may be helpful for distinguishing tumor shrinkage from tumor fragmentation. In addition, second harmonic generation imaging shows the ability to monitor three types of fibrotic responses: mature, intermediate, and immature. We also determined nonlinear spectra, collagen density, and collagen orientation indexes to quantitatively analyze the histopathologic changes induced by neoadjuvant therapy in rectal cancer. Our work demonstrates that nonlinear optical microscopy has the potential to become a label-free, real-time, in vivo medical imaging technique and provides the groundwork for further exploration into the application of nonlinear optical microscopy in a clinical setting.

A Distal Resection Margin of ≤1 mm and Rectal Cancer Recurrence After Sphincter-Preserving Surgery: The Role of a Positive Distal Margin in Rectal Cancer Surgery

BACKGROUND

There is little information about the prognostic value of a microscopically positive distal margin in patients who have rectal cancer.

OBJECTIVE

We aimed to investigate the influence of a distal margin of ≤1 mm on oncologic outcomes after sphincter-preserving resection for rectal cancer.

DESIGN

This is a retrospective cohort study.

SETTINGS

The study was conducted at 2 hospitals.

PATIENTS

A total of 6574 patients underwent anterior resection for rectal cancer from January 1999 to December 2014; 97 (1.5%) patients with a distal margin of ≤1 mm were included in this study. For comparative analyses, patients were matched with 194 patients with a negative distal margin (>1 mm) according to sex, age, BMI, ASA score, neoadjuvant treatment, tumor location, and stage.

MAIN OUTCOME MEASURES

The oncologic outcomes of the 2 groups were compared.

RESULTS

Perineural and lymphovascular invasion rates were significantly higher in patients with a positive distal margin (54.6% vs 28.9%; 67.0% vs 42.8%; both p < 0.001) compared with to patients with negative distal margin. Comparison between microscopically positive and negative distal margin showed worse oncologic outcomes in patients with a microscopically positive distal margin, including 5-year local recurrence rate (24.1% vs 12.0%, p = 0.005); 5-year distant recurrence rate (35.5% vs 20.2%, p = 0.011); 5-year disease-free survival (45.5% vs 69.5%, p < 0.001); and 5-year OS (69.2% vs 79.7%, p = 0.004). Among the 97 patients with a microscopically positive distal margin, the 5-year disease-free survival rate was higher in patients who received adjuvant therapy (52.0% vs 30.7%, p = 0.089).

LIMITATIONS

This is a retrospective study; bias may exist.

CONCLUSIONS

A distal margin of 1 mm is associated with worse oncologic results. Our data indicate the importance of achieving a clear distal margin in the surgical treatment of rectal cancer. Adjuvant therapy should be used in these patients to reduce recurrence. See Video Abstract at http://links.lww.com/DCR/A408.

Tumor regression grading of gastrointestinal cancers after neoadjuvant therapy

Neoadjuvant therapy has been successfully introduced in the treatment of locally advanced gastrointestinal malignancies, particularly esophageal, gastric, and rectal cancers. The effects of preoperative chemo- or radiochemotherapy can be determined by histopathological investigation of the resection specimen following this treatment. Frequent histological findings after neoadjuvant therapy include various amounts of residual tumor, inflammation, resorptive changes with infiltrates of foamy histiocytes, foreign body reactions, and scarry fibrosis. Several tumor regression grading (TRG) systems, which aim to categorize the amount of regressive changes after cytotoxic treatment in primary tumor sites, have been proposed for gastroesophageal and rectal carcinomas. These systems primarily refer to the amount of therapy-induced fibrosis in relation to the residual tumor (e.g., the Mandard, Dworak, or AJCC systems) or the estimated percentage of residual tumor in relation to the previous tumor site (e.g., the Becker, Rödel, or Rectal Cancer Regression Grading systems). TRGs provide valuable prognostic information, as in most cases, complete or subtotal tumor regression after neoadjuvant treatment is associated with better patient outcomes. This review describes the typical histopathological findings after neoadjuvant treatment, discusses the most commonly used TRG systems for gastroesophageal and rectal carcinomas, addresses the limitations and critical issues of tumor regression grading in these tumors, and describes the clinical impact of TRG.

A critical reappraisal for the value of tumor size as a prognostic variable in rectal adenocarcinoma

Background and Objectives: To investigate critical prognostic factors for local recurrence in patients with rectal adenocarcinoma. Methods: We enrolled 221 consecutive patients who had histologically confirmed adenocarcinoma of the rectum and underwent surgery in our hospital between January 2000 and December 2014. Total mesorectal excision was performed in all patients undergoing a sphincter-sparing procedure or abdominal perineal resection of rectal cancer. To evaluate prognostic factors for local recurrence, we performed univariate and multivariate Cox regression analyses of the local recurrence rate in all patients. Overall survival rates were calculated using the Kaplan-Meier method, and Kaplan-Meier survival curves were compared using the log-rank test. Results: After the inclusion of only model variables of local recurrence with the highest or lowest univariate risk, a tumor size of <5 cm, a negative circumferential margin, well-to-moderately differentiated adenocarcinoma, low anterior resection, not receiving adjuvant RT, pathological T1-T3 stages, and upper- and middle-third rectal cancers were identified as strong prognostic factors with hazard ratios of 0.18, 0.20, 0.03, 0.01, 0.25, 0.18 and 0.18, respectively (95% confidence intervals [CIs], 0.06-0.58, 0.05-0.82, 0.03-0.38, 0.04-0.23, 0.05-0.64,0.09-0.70 and 0.06-0.54, respectively). After the multivariate Cox regression analysis of the local recurrence rate, a pathological tumor size of ≥5 cm was identified as the only prognostic risk factor (95% CI, 0.03-0.66; P = 0.013). The 5-year local recurrence rates among the patients having tumors measuring <5 cm and ≥5 cm in size were 1.40% and 23.00%, respectively (log-rank, P = 0.0001). The 5-year overall survival rates in the patients having tumors measuring <5 cm and ≥5 cm in size were 82.60% and 71.20%, respectively (log-rank, P = 0.001). Conclusion: A pathological tumor size of ≥5 cm is an independent prognostic factor for local recurrence in rectal adenocarcinoma.

Does the depth of mesorectal invasion have prognostic significance in patients with ypT3 lower rectal cancer treated with preoperative chemoradiotherapy?

PURPOSE

The prognostic significance of the depth of mesorectal invasion (DMI) in patients with ypT3 rectal cancer who undergo preoperative chemoradiotherapy (CRT) is unclear. The purpose of this study was to evaluate the prognostic significance of DMI in ypT3 rectal cancer.

METHODS

A total of 168 (y)pT3 patients were evaluated, of whom 93 received preoperative CRT and 75 underwent surgery alone. Patients were subdivided into two groups according to the DMI (T3ab = DMI ≤5 mm and T3cd = DMI >5 mm). Oncologic outcomes were compared between the T3ab and T3cd groups and the ypT3ab and ypT3cd groups.

RESULTS

Relapse-free survival was significantly different between the pT3ab and pT3cd groups (74.1 vs 38.5%, P = 0.0192) but not between the ypT3ab and ypT3cd groups (65.9 vs 61.5%, P = 0.513). Multivariate analysis showed that DMI was an independent predictor of recurrence in pT3 patients (hazard ratio [HR] = 2.980, 95% confidence interval [CI] 1.227-7.025; P = 0.0169) and that ypN+ was an independent predictor of recurrence in ypT3 patients (HR = 3.487, 95% CI 1.570-8.827; P = 0.0016).

CONCLUSIONS

DMI was not a significant predictive factor for recurrence in patients with ypT3 rectal cancer who underwent preoperative CRT, and ypN+ was the only independent predictive factor for recurrence.

Does neoadjuvant therapy increase the incidence of anastomotic leakage after anterior resection for mid and low rectal cancer? A systematic review and meta-analysis

AIM

The aim was to evaluate the association of neoadjuvant therapy with increases in the incidence of anastomotic leakage (AL) after middle and low rectal anterior resection.

METHOD

The electronic databases of PubMed, Web of Science, Scopus and Ovid were searched between 1980 and 2015. The random effects model was used to model the pooled data to determine the odds ratio with 95% confidence interval. Heterogeneity was evaluated using the Q test and I² statistics. Subgroup, sensitivity and meta-regression analysis was conducted to explore heterogeneity.

RESULTS

Neoadjuvant therapy was not shown to increase the incidence of postoperative AL as demonstrated by an OR of 1.16 [95% CI 0.99-1.36; P = 0.07 (random effects model)]. The subgroup analysis of neoadjuvant radiotherapy using the random effects model suggested that it did not increase the rate of postoperative AL (OR = 1.24, 95% CI 0.97-1.58; P = 0.08). The subgroup analysis of neoadjuvant chemoradiotherapy indicated that the rate of postoperative AL again did not increase with an OR = 1.06 [95% CI 0.86-1.30; P = 0.59 (random effects model)]. The interval to surgery after neoadjuvant therapy and preoperative radiotherapy (short or long course) was not associated with an increased incidence of postoperative AL.

CONCLUSION

Neoadjuvant therapy does not appear to increase the incidence of postoperative AL after anterior resection for mid and low rectal cancer. In addition, neither the interval to surgery after neoadjuvant therapy nor the radiotherapy regimen increases the rate of postoperative AL.