Prognostic value of tumour regression grade in locally advanced rectal cancer: a systematic review and meta-analysis

A non-randomised open-label exploratory 'window of opportunity' study of TG02 treatment in patients with locally advanced primary and recurrent RAS mutant colorectal cancer

Background

TG02 is a peptide-based cancer vaccine eliciting immune responses to oncogenic codon 12/13 RAS mutations. This phase 1 clinical trial (NCT02933944) assessed the safety and immunological efficacy of TG02 adjuvanted by GM-CSF in patients with KRAS-mutant colorectal cancer.

Methods

In the interval between completing CRT and pelvic exenteration, patients with resectable KRAS mutation-positive, locally advanced primary or current colorectal cancer, received 5-6 doses of TG02/GM-CSF. Immune response was defined as a positive delayed-type hypersensitivity or positive T cell proliferation assay response. Tumour biopsies were analysed for tumour-infiltrating lymphocytes (TILs) and blood for CEA and ctDNA. TILs and tumouroids were cultured, characterised and tested for their killing efficacy.

Results

Six patients with rectal cancer were recruited to evaluate TG02. Three patients experienced a total of 16 treatment-related adverse events; all grade 1. Four of the 6 patients (66.7 %) had at least one vaccine-induced TG02 immune response. Flow cytometry analysis showed high proportion of PD-1-expressing TILs in 2 of 3 patient specimens' post-treatment. A partial to near complete pathological response was reported in 4 of 6 patients.

Conclusions

This study demonstrated that TG02/GM-CSF was well tolerated and induced a vaccine specific systemic immune response in the majority of patients. Low numbers limit conclusive clinical outcome reporting. High PD-1 expression on post-treatment TILs encourages the addition of an immune checkpoint inhibitor to TG02 and potentially other studies of peptide vaccines in future studies.

Impact of pathological complete response on survival in gastric cancer after neoadjuvant chemotherapy: a propensity score matching analysis

PURPOSE

The survival benefits of neoadjuvant chemotherapy (NAC) for locally advanced gastric cancer (LAGC) patients are inconsistent. This study aims to investigate how different tumor regression grades (TRG) influence the survival gains associated with NAC treatment.

METHODS

This study compared the treatment outcomes of patients who underwent CSC (neoadjuvant chemotherapy - surgery - adjuvant chemotherapy) with those receiving traditional SC (surgery - adjuvant chemotherapy) treatment. Propensity score matching (PSM) was employed to minimize potential biases arising from differences in baseline characteristics and intervention factors between the treatment groups. After PSM, the CSC cohort was stratified according to TRGs, and their survival outcomes were compared to assess the impact of TRGs on survival gains associated with NAC.

RESULTS

Before PSM, a total of 506 patients were enrolled: 291 in the CSC cohort and 215 in the SC cohort. The CSC cohort had a lower 3-year survival rate (3Y-SR) than the SC cohort (64.6% vs. 76%). In the CSC cohort, patients who achieved pathological complete response (pCR, 12.1%, 26/215) demonstrated significantly improved 3Y-SR (95.5%). After PSM, 110 patients were matched in each cohort. The 3Y-SR was similar between the CSC cohort (68.3%) and the SC cohort (63.6%). In the CSC cohort, 12.7% (14/110) of patients achieved pCR. Subgroup analysis revealed that the pCR subgroup (3Y-SR 100%) was the only subgroup within the CSC cohort that maintained significantly improved survival compared to the SC cohort. Better tumor differentiation was the only pre-treatment factor significantly associated with achieving pCR (p < 0.001).

CONCLUSION

In this retrospective study, LAGC patients who achieved pCR after NAC demonstrated significantly better survival outcomes compared to other response groups. The study found tumor differentiation was a potential predictor of pCR.

Prognostic Value of Tumor Regression Grade Combined with Pathological Lymph Node Status in Initially Node-Positive Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy

BACKGROUND

The prognostic value of tumor regression grade (TRG) after neoadjuvant chemoradiotherapy for rectal cancer is inconsistent in the literature. Both TRG and post-therapy lymph node (ypN) status could reflect the efficacy of neoadjuvant therapy. Here, we explored whether TRG combined with ypN status could be a prognostic factor for MRI-based lymph node-positive (cN+) rectal cancer following neoadjuvant chemoradiotherapy.

METHODS

671 cN + rectal cancer patients who received neoadjuvant chemoradiotherapy followed by radical resection were enrolled. Patients were innovatively divided into three groups based on TRG and ypN status: TRG0-1N0, TRG2-3N0 or TRG0-1N+, TRG2-3N+. Kaplan-Meier method and log-rank test were used to compare the disease-free survival (DFS) and overall survival (OS) among three groups. Univariate and multivariate analyses were performed to explore the prognostic value of the modified TRG in cN + rectal cancer following neoadjuvant chemoradiotherapy.

RESULTS

The mean duration of follow-up was 30.4 months. Significant survival differences were observed among the three groups. The 3-year DFS were 83.0%, 69.2% and 55.9%, respectively. The 5-year OS were 83.5%, 80.4% and 57.8%, respectively. TRG combined with ypN status was an independent predictor for both DFS and OS in multivariate analysis.

CONCLUSION

TRG combined with ypN status is a novel prognostic factor in cN + rectal cancer following neoadjuvant chemoradiotherapy, which assists clinicians make appropriate decisions regarding postoperative treatment and surveillance.

Not All Patients With Locally Advanced Rectal Cancer Benefit From Neoadjuvant Therapy

BACKGROUND

While neoadjuvant combined modality therapy (NA-CMT) is beneficial for most patients with locally advanced rectal cancer some patients may experience disease progression during treatment. The purpose of this study is to identify characteristics associated with progression during NA-CMT.

METHODS

A single institution retrospective review of patients with stage II-III rectal cancer receiving NA-CMT was conducted from 2008-2019. Patients with incomplete or unknown NA-CMT treatment and those who received chemotherapy in addition to NA-CMT were excluded. Initial staging MRI was compared to post-operative pathology to determine progression. Definitions: responders (complete response or regression) and non-responders (stable disease or progression).

RESULTS

156 patients were included: 25 (16.1%) complete responders, 79 (50.6%) had evidence of regression, 34 (21.8%) were stable non-responders, and 18 (11.5%) were progressors. Those who progressed had worse overall survival. Factors associated with non-responders included black race (OR 4.5, 95% CI: 1.10-18.7) and increasing distance from the anal verge (OR 1.2, 95% CI: .2-2.9). Distance from the anal verge was determined via MRI. Recurrence was significantly more common among non-responders (15, 30.61%) when compared to responders (14, 13.46%), P = .012.

CONCLUSION

Patients who progress despite NA-CMT have overall worse survival compared to patients who do respond. While this study failed to identify modifiable or predictive risk factors for progression, the multivariate logistic regression model suggests that race and tumor biology may play a role in progression. Future studies should focus on early identification of patients who may not benefit from NA-CMT in an effort to develop alternative treatment algorithms.

The neoadjuvant rectal score and a novel magnetic resonance imaging based neoadjuvant rectal score are stage independent predictors of long-term outcome in locally advanced rectal cancer

AIM

Neoadjuvant rectal (NAR) score is an early surrogate for longer-term outcomes in rectal cancer undergoing radiotherapy and resection. In an era of increasing organ preservation, resection specimens are not always available to calculate the NAR score. Post-treatment magnetic resonance imaging (MRI) re-staging of regression is subjective, limiting reproducibility. We explored the potential for a novel MRI-based NAR score (mrNAR) adapted from the NAR formula.

METHODS

Locally advanced rectal cancer patients undergoing neoadjuvant therapy (nCRT) and surgery were retrospectively identified between 2008 and 2020 in a single cancer network. mrNAR was calculated by adapting the NAR formula, replacing pathological (p) stages with post-nCRT MR stages (ymr). Cox regression assessed relationships between clinicopathological characteristics, NAR and mrNAR with overall survival (OS) and recurrence-free survival (RFS).

RESULTS

In total, 381 NAR and 177 mrNAR scores were calculated. On univariate analysis NAR related to OS (hazard ratio [HR] 2.05, 95% confidence interval [CI] 1.33-3.14, p = 0.001) and RFS (HR 2.52, 95% CI 1.77-3.59, p = 0.001). NAR 3-year OS <8 was 95.3%, 8-16 was 88.6% and >16 was 80%. mrNAR related to OS (HR 2.96, 95% CI 1.38-6.34, p = 0.005) and RFS (HR 2.99, 95% CI 1.49-6.00, p = 0.002). 3-year OS for mrNAR <8 was 96.2%, 8-16 was 92.4% and >16 was 78%. On multivariate analysis, mrNAR was a stage-independent predictor of OS and RFS. mrNAR corresponded to NAR score category in only 15% (positive predictive value 0.23) and 47.5% (positive predictive value 0.48) of cases for categories <8 and >16, respectively.

CONCLUSIONS

Neoadjuvant rectal score is validated as a surrogate end-point for long-term outcomes. mrNAR categories do not correlate with NAR but have stage-independent prognostic value. mrNAR may represent a novel surrogate end-point for future neoadjuvant treatments that focus on organ preservation.

Improved Survival After Adjuvant Therapy in Locally Advanced Rectal Cancer Patients With Pathologic Complete Response

BACKGROUND

The benefit of adjuvant therapy is unclear in patients with rectal cancer achieving a pathologic complete response after neoadjuvant chemoradiotherapy and total mesorectal excision.

OBJECTIVE

This study aimed to assess the benefit of adjuvant chemotherapy on survival among rectal cancer patients with a pathologic complete response after neoadjuvant chemoradiation.

DESIGN

Retrospective cohort study.

SETTING

National Cancer Database (2004-2017).

PATIENTS

Patients with clinical stage 2 or 3 rectal adenocarcinoma who underwent neoadjuvant chemoradiation (50-50.4 Gy in 25-28 fractions) followed by total mesorectal excision with a pathologic complete response were included.

INTERVENTION

Adjuvant chemotherapy.

MAIN OUTCOME MEASURES

Overall survival.

RESULTS

There were 20,518 patients and 2221 (11%) had a pathologic complete response after neoadjuvant chemoradiation. Of 2221 patients, 1441 (65%) did not receive adjuvant therapy and 780 (35%) did. Patients who received adjuvant therapy were more likely to be younger (median 58 vs 62 y), have private insurance (61% vs 49%), and have node-positive disease (57% vs 48%) (all p < 0.05). There were no differences in sex, race, Charlson-Deyo score, clinical T-stage, tumor size and differentiation, adequate lymphadenectomy (12 or more), or sphincter preservation between groups (all p > 0.05). Overall survival at 5, 10, and 14 years was significantly longer in the adjuvant group (93%, 85%, 83%, respectively) compared to patients who did not receive adjuvant therapy (87%, 67%, 51%, respectively) ( p < 0.001). In a subgroup analysis, adjuvant therapy was associated with improved survival in patients with clinical stage 2 and 3 rectal cancer ( p < 0.001). After adjusting for patient and tumor characteristics, omission of adjuvant chemotherapy was associated with significantly worse survival (HR 1.53, 95% 1.08-2.16).

LIMITATIONS

Selection bias, unknown perioperative morbidity, chemotherapy regimen, recurrence status, and other unidentified factors limiting survival analysis.

CONCLUSIONS

In patients with clinical stage 2 or 3 rectal cancer, adjuvant chemotherapy was associated with improved overall survival in patients achieving a pathological complete response after neoadjuvant chemoradiotherapy. See Video Abstract at http://links.lww.com/DCR/C139 .

SOBREVIDA MEJORADA DESPUS DE LA TERAPIA ADYUVANTE EN PACIENTES CON CNCER DE RECTO LOCALMENTE AVANZADO CON RESPUESTA PATOLGICA COMPLETA

ANTECEDENTES:En los pacientes con cáncer de recto que logran una respuesta patológica completa después de la quimiorradioterapia neoadyuvante y la escisión total del mesorrecto, el beneficio de la terapia adyuvante no está claro.OBJETIVO:Evaluar el beneficio de la quimioterapia adyuvante en la sobrevida de los pacientes con cáncer de recto con una respuesta patológica completa después de la quimiorradioterapia neoadyuvante.DISEÑO:Estudio de cohorte retrospectivo.ESCENARIO:Base de Datos Nacional de Cáncer (2004-2017).PACIENTES:Pacientes con adenocarcinoma rectal en estadio clínico 2 ó 3 que se sometieron a quimiorradiación neoadyuvante (50-50,4 Gy en 25-28 fracciones) seguida de escisión mesorrectal total con una respuesta patológica completa.INTERVENCIÓN:Quimioterapia adyuvante.PRINCIPALES MEDIDAS DE RESULTADO:Sobrevida global.RESULTADOS:Hubo 20.518 pacientes y 2.221 (11%) tuvieron una respuesta patológica completa después de la quimiorradiación neoadyuvante. Entre estos 2221 pacientes, 1441 (65%) no recibieron terapia adyuvante y 780 (35%) sí. Los pacientes que recibieron terapia adyuvante tenían más probabilidades de ser más jóvenes (mediana de 58 frente a 62 años), tener un seguro privado (61% frente a 49%) y tener enfermedad con linfonodos positivos (57% frente a 48 %) (todos p < 0,05). No hubo diferencias en género, raza, puntuación de Charlson-Deyo, estadio T clínico, tamaño y diferenciación del tumor, linfadenectomía adecuada (≥12) o preservación del esfínter entre los grupos (todos p > 0,05). La sobrevida general a los 5, 10 y 14 años fue significativamente mayor en el grupo adyuvante (93%, 85%, 83%, respectivamente) en comparación con los pacientes que no recibieron terapia adyuvante (87%, 67%, 51% respectivamente) ( p < 0,001). En un análisis de subgrupos, la terapia adyuvante se asoció con una mejor sobrevida general en pacientes con cáncer de recto en estadio clínico 2 y 3 ( p < 0,001). Después de ajustar por las características del paciente y del tumor, la omisión de la quimioterapia adyuvante se asoció con una sobrevida global significativamente peor (HR 1,53, IC del 95%, 1,08-2,16).LIMITACIONES:Sesgo de selección; morbilidad perioperatoria desconocida, régimen de quimioterapia, estado de recurrencia y otros factores no identificados que limitan el análisis de sobrevida.CONCLUSIONES:En pacientes con cáncer de recto en estadio clínico 2 ó 3, la quimioterapia adyuvante se asoció con una mejor sobrevida general en pacientes que lograron una respuesta patológica completa después de la quimiorradioterapia neoadyuvante. Consulte Video Resumen en http://links.lww.com/DCR/C139 . (Traducción-Dr. Felipe Bellolio ).

Does Sarcopenia Predict Local Response Rates After Chemoradiotherapy for Locally Advanced Rectal Cancer?

BACKGROUND

The predictive value of sarcopenia for tumor response to neoadjuvant chemoradiotherapy is unclear.

OBJECTIVE

This study aimed to investigate the association between sarcopenia and pathological tumor regression grade after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer.

DESIGN

Retrospective cohort study from a prospectively collected database. Univariate logistic regression was performed to assess the association between sarcopenia and tumor response.

SETTINGS

This study was conducted at 2 tertiary care centers.

PATIENTS

Participants were patients undergoing neoadjuvant chemoradiotherapy for locally advanced rectal cancer (T3/4, N0/+) between 2007 and 2018.

INTERVENTION

Sarcopenia was diagnosed using sex-specific cutoffs of lean muscle mass. Using the initial staging CT, lean muscle mass was estimated using the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra, normalized for patient height.

MAIN OUTCOME MEASURES

The primary end point was pathological tumor regression grade, defined as good (tumor regression grade 0/1) vs poor (tumor regression grade 2/3).

RESULTS

The study included 167 patients with locally advanced rectal cancer with a median age of 60 (20-91) years, with 132 in the nonsarcopenia group and 35 in the sarcopenia group. Eighty-nine percent of patients had stage 3 cancer. Nine patients (5.4%) had a complete clinical response, 1 patient did not respond to treatment and opted for nonoperative management, and the remaining 157 patients (94.0%) proceeded to surgery. Pathological data revealed no significant difference between good tumor regression grade patients in the sarcopenia group compared with the nonsarcopenia group. Univariate analysis revealed BMI ≥25 kg/m 2 to be a risk factor for good tumor regression grade ( p = 0.002).

LIMITATIONS

This study was limited by its retrospective design and small sample size.

CONCLUSIONS

Sarcopenia is not a predictor of poor neoadjuvant chemoradiotherapy response in patients with locally advanced rectal cancer. Increasing BMI was associated with good tumor regression grade. Future multicentered studies are warranted to validate this finding. See Video Abstract at http://links.lww.com/DCR/C78 .

LA SARCOPENIA PREDICE LAS TASAS DE RESPUESTA LOCAL DESPUS DE LA QUIMIORRADIOTERAPIA PARA EL CNCER DE RECTO LOCALMENTE AVANZADO

ANTECEDENTES:El valor predictivo de la sarcopenia para la respuesta tumoral a la quimiorradioterapia neoadyuvante no está claro.OBJETIVO:Este estudio investiga la asociación entre la sarcopenia y el grado de regresión tumoral patológica después de la quimiorradioterapia neoadyuvante en pacientes con cáncer de recto localmente avanzado.DISEÑO:Estudio de cohorte retrospectivo a partir de una base de datos recolectada prospectivamente. Se realizó una regresión logística univariante para evaluar la asociación entre la sarcopenia y la respuesta tumoral.ENTORNO CLINICO:Este estudio se realizó en dos centros de atención terciaria.PACIENTES:Pacientes sometidos a quimiorradioterapia neoadyuvante por cáncer de recto localmente avanzado (T3/4, N0/+) entre 2007-2018.INTERVENCIÓNES:La sarcopenia se diagnosticó utilizando puntos de corte de masa muscular magra específicos por género. Utilizando la tomografía computarizada de estadificación inicial, se estimó la masa muscular magra utilizando el área transversal del músculo psoas a nivel de la tercera vértebra lumbar, normalizada para la altura del paciente.PRINCIPALES MEDIDAS DE VALORACIÓN:El criterio principal de valoración fue el grado de regresión tumoral patológica, definido como bueno (grado de regresión tumoral 0/1) frente a malo (grado de regresión tumoral 2/3).RESULTADOS:El estudio incluyó a 167 pacientes con cáncer de recto localmente avanzado con una mediana de edad de 60 años (20-91), 132 en el grupo sin sarcopenia y 35 en el grupo con sarcopenia. Ochenta y nueve por ciento estaban en etapa III. Seis pacientes (5,4%) tuvieron respuesta clínica completa sostenida, un paciente no respondió al tratamiento y optó por manejo conservador, los 157 restantes (94,0%) procedieron a cirugía. Los datos patológicos no revelaron diferencias significativas entre los pacientes con buen grado de regresión tumoral en el grupo de sarcopenia en comparación con el grupo sin sarcopenia. El análisis univariado reveló que un IMC ≥25 kg/m2 era un factor de riesgo para un buen grado de regresión tumoral (p = 0,002).LIMITACIONES:Este estudio estuvo limitado por su diseño retrospectivo y tamaño de muestra pequeño.CONCLUSIÓNES:La sarcopenia no es un predictor de mala respuesta a la quimiorradioterapia neoadyuvante en pacientes con cáncer de recto localmente avanzado. El aumento del IMC se asoció con un buen grado de regresión tumoral. Se justifican futuros estudios multicéntricos para validar este hallazgo. Consulte Video Resumen en http://links.lww.com/DCR/C78 . (Traducción-Dr. Ingrid Melo ).

Correlative Significance of Tumor Regression Grade and ypT Category in Patients Undergoing Preoperative Chemoradiotherapy for Locally Advanced Rectal Cancer

BACKGROUND

In patients with locally advanced rectal cancer, the treatment response to preoperative chemoradiotherapy (PRCRT) varies, and the ypT stage may change as a result of tumor shrinkage. The purpose of this study was to evaluate the correlative significance and determine the prognostic value of tumor regression grade and ypT category staging systems.

MATERIALS AND METHODS

This retrospective observational study was conducted in a tertiary center. A total of 1240 patients with rectal cancer who underwent curative resection after PRCRT between January 2007 and December 2016 were consecutively included.

RESULTS

A significant association was found between the American Joint Committee on Cancer/College of American Pathology tumor regression grading system and ypT category, indicating a potential correlation between worse tumor regression grade and more advanced T stage (Cramer's V = 0.255, P < .001). The ypT stage and tumor regression grade were independent predictors of each other (P < .001). The good response group (tumor regression grades 0-1) had significantly higher 5-year disease-free survival (85.5% vs. 68.2%, P < .001) and overall survival (92.1% vs. 81.0%, P < .001) rates than the poor response group (tumor regression grades 2-3). However, the ypT and ypN categories were the most important independent prognostic factors for disease-free and overall survival.

CONCLUSIONS

Tumor regression grade and ypT category were significantly correlated. Although tumor regression grade alone is not definitive, it is closely related to the ypT stage and impacts oncologic outcomes. These findings should be taken into consideration when stratifying the prognosis of patients undergoing PRCRT.

Predictive value of proteomic markers for advanced rectal cancer with neoadjuvant chemoradiotherapy

Background

Preoperative neoadjuvant chemoradiation (nCRT) has been the standard treatment for locally advanced rectal cancer. Serum biomarkers to stratify patients with respect to prognosis and response to nCRT are needed due to the diverse response to the therapy.

Methods

Thirteen paired pre- and post-nCRT sera from rectal cancer patients were analyzed by isobaric tags for relative and absolute quantitation (iTRAQ) method. Twenty-five proteins were selected for validation by parallel reaction monitoring (PRM) in ninety-one patients.

Results

Totally, 310 proteins were identified and quantified in sera samples. Reactome pathway analysis showed that the immune activation-related pathways were enriched in response to nCRT. Twenty-five proteins were selected for further validation. PRM result showed that the level of PZP was higher in pathological complete response (pCR) patients than non-pCR patients. The Random Forest algorithm identified a prediction model composed of 10 protein markers, which allowed discrimination between pCR patients and non-pCR patients (area under the curve (AUC) = 0.886 on testing set). Higher HEP2 and GELS or lower S10A8 in baseline sera were associated with better prognosis. Higher APOA1 in post nCRT sera was associated with better disease-free survival (DFS).

Conclusions

We identified and confirmed a 10-protein panel for nCRT response prediction and four potential biomarkers HEP2, GELS, S10A8 and APOA1 for prognosis of rectal cancer based on iTRAQ-based comparative proteomics screening and PRM-based targeted proteomic validation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09960-z.

BCL-3 loss sensitises colorectal cancer cells to DNA damage by targeting homologous recombination

The proto-oncogene BCL-3 is upregulated in a subset of colorectal cancers (CRC), where it has been shown to enhance tumour cell survival. However, although increased expression correlates with poor patient prognosis, the role of BCL-3 in determining therapeutic response remains largely unknown. In this study, we use combined approaches in multiple cell lines and pre-clinical mouse models to investigate the function of BCL-3 in the DNA damage response. We show that suppression of BCL-3 increases γH2AX foci formation and decreases homologous recombination in CRC cells, resulting in reduced RAD51 foci number and increased sensitivity to PARP inhibition. Importantly, a similar phenotype is seen in Bcl3-/- mice, where Bcl3-/- mouse crypts also exhibit sensitivity to DNA damage with increased γH2AX foci compared to wild type mice. Additionally, Apc.Kras-mutant x Bcl3-/- mice are more sensitive to cisplatin chemotherapy compared to wild type mice. Taken together, our results identify BCL-3 as a regulator of the cellular response to DNA damage and suggests that elevated BCL-3 expression, as observed in CRC, could increase resistance of tumour cells to DNA damaging agents including radiotherapy. These findings offer a rationale for targeting BCL-3 in CRC as an adjunct to conventional therapies and suggest that BCL-3 expression in tumours could be a useful biomarker in stratification of rectal cancer patients for neo-adjuvant chemoradiotherapy.

Extramural venous invasion (EMVI) revisited: a detailed analysis of various characteristics of EMVI and their role as a predictive imaging biomarker in the neoadjuvant treatment response in rectal cancer

PURPOSE

To assess whether size, diameter, and large vein involvement of MR-detected extramural venous invasion (MR-EMVI) have an impact on neoadjuvant therapy response in rectal adenocarcinoma.

METHODS

57 patients with locally advanced rectal adenocarcinoma scanned with MRI before and after neoadjuvant therapy were included. Two abdominal radiologists evaluated the images with special emphasis on EMVI, on initial staging and after neoadjuvant treatment. The sensitivity and specificity of MRI for detection of rest EMVI were determined. The association of various MR-EMVI characteristics including number, size, and main vein involvement with treatment response was investigated. In subjects with discordance of radiology and pathology, elastin stain was performed, and images and slides were re-evaluated on site with a multidisciplinary approach.

RESULTS

At initial evaluation, 17 patients were MR-EMVI negative (29.8%) and 40 were MR-EMVI positive (70.2%). Complete/near-complete responders had less number (mean 1.45) and smaller diameter of MR-EMVI (mean 1.8 mm), when compared with partial responders (2.54 and 3.3 mm; p < 0.005). The sensitivity of MRI for rest EMVI detection was high, specificity was moderate, and in one patient elastin stain changed the final decision. In five patients with rest MR-EMVI positivity, carcinoma histopathologically had a distinctive serpiginous perivascular spread, growing along the track of vascular bundle, although it did not appear in intravascular spaces.

CONCLUSION

This study demonstrates that not only the presence, but also size and number of EMVI that may be significant clinically and thus these parameters also ought to be incorporated to the MRI evaluation and prognostication of treatment response. From pathology perspective, tumors growing alongside major vessels may also reflect EMVI even if they are not demonstrably "intravascular."

Tumor Regression Grade as a Prognostic Factor in Metastatic Colon Cancer Following Preoperative Chemotherapy

BACKGROUND

The prognostic value of tumor regression grade (TRG) in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy has been explored extensively. However, whether TRG is predictive of outcome in colon cancer following preoperative chemotherapy has not been reported.

MATERIALS AND METHODS

A total of 276 colon cancer patients who had undergone preoperative chemotherapy and surgery in Fudan University Shanghai Cancer Center during the period March 2014 through November 2019 were recruited in this study. 113 (40.9%) and 163 (59.1%) patients were diagnosed with locally advanced colon cancer (LACC) and metastatic colon cancer (mCC) before preoperative chemotherapy, respectively. The TRG was divided into TRG0 (complete response), TRG1 (good response), TRG2 (moderate response), and TRG3 (poor response).

RESULTS

Of the 276 patients 4.0% were TRG0, 5.4% were TRG1, 29.3% were TRG2, 61.2% were TRG3. TRG0 and TRG1 or TRG0, TRG1 and TRG2 were combined to simplify analysis due to limited sample size. In entire cohort, the 3-year overall survival for TRG0-1, TRG2, and TRG3 groups were 80.0%, 68.8% and 43.3% (P = .003). In LACC cohort, TRG was not associated with patients' prognosis, which largely resulted from limited outcome events. In mCC cohort, the 3-year overall survival for TRG0-1, TRG2, and TRG3 groups were 74.3%, 62.8% to 28.1% (P<0.001). Multivariate analysis demonstrated that TRG was an independent prognostic factor for overall survival in both entire cohort and mCC cohort (TRG3 vs. TRG0-2).

CONCLUSION

TRG is a prognostic factor in predicting long-term outcomes of mCC patients treated with preoperative chemotherapy.

More Is Not Better When It Comes to Treating Rectal Cancer With Multimodal Chemoradiation Beyond the Standard Radiation Dose of 5040 cGy

BACKGROUND

Radiation dose schedules for neoadjuvant chemoradiation for rectal cancers differ, with the most common dose schedule using 5040 cGy in 28 fractions.

OBJECTIVES

The aim of this retrospective study was to assess the benefit of higher radiation doses beyond 5040 cGy in the context of pathological response and follow-up events.

SETTING

The database from a provincial tertiary cancer center in Canada was the source of information for this study.

PATIENTS

Included in this study were 508 consecutive patients with rectal cancer with locally advanced disease (clinical T3/T4 or N1/N2) who received neoadjuvant chemoradiation followed by surgery. Of the 508 patients, 281 received the standard radiation dose of 4500 to 5040 cGy and 227 received a dose >5040 cGy.

MAIN OUTCOME MEASURE

The postsurgical pathology, late toxicities, and follow-up outcomes were analyzed. The outcomes were evaluated in relation to the dose of radiation received.

RESULTS

Data regarding the clinical outcomes were comparable between the 4500 to 5040 cGy and >5040 cGy radiation groups with pathological complete response rates of 20.9% and 15.4% (p = 0.104); distant recurrence rates of 17.4% and 19.4% (p = 0.36); local recurrence rates of 3.2% and 3.5% (p = 0.36); and the median overall survival rates of 61 and 60.5 months (p = 0.8). No statistically significant correlation of improvement in outcomes was noted with radiation doses beyond 5040 cGy.

LIMITATIONS

This is a retrospective study.

CONCLUSION

Our study showed that dose escalation beyond the standard dose of 4500 to 5040cGy failed to achieve meaningful clinical outcomes. See Video Abstract at http://links.lww.com/DCR/B633.

MS NO ES MEJOR CUANDO SE TRATA DE TRATAR EL CNCER DE RECTO CON QUIMIORRADIACIN MULTIMODAL MS ALL DE LA DOSIS DE RADIACIN ESTNDAR DE CGY

ANTECEDENTES:En neoadyuvancia de cáncer rectal es posible encontrar muchas variaciones, en radioterapia la dosis más común que usa 5040 cGy en 28 fracciones.OBJETIVOS:El objetivo de este estudio retrospectivo fue evaluar el beneficio de dosis de radiación más altas más allá de 5040cGy en el contexto de la respuesta patológica y en su seguimiento.AJUSTE:Base de datos de un centro de cáncer terciario provincial en Canadá.PACIENTES:Se incluyeron en este estudio quinientos ocho pacientes consecutivos con cáncer de recto y enfermedad localmente avanzada (clínica T3 / T4 o N1 / N2) que recibieron quimiorradiación neoadyuvante seguida de cirugía. De los 508 pacientes, 281 recibieron la dosis de radiación estándar de 4500-5040 cGy y 227 recibieron una dosis > 5040 cGy.PRINCIPAL MEDIDA DE RESULTADO:Se analizo evolucion posquirúrgica, toxicidad tardía y seguimiento. Los resultados se evaluaron en relación con la dosis de radiación recibida.RESULTADOS:Los datos con respecto a los resultados clínicos fueron comparables entre los grupos de radiación de 4500-5040 cGy y> 5040 cGy con tasas de respuesta patológica completa de 20,9% y 15,4% respectivamente (p = 0,104); tasas de recurrencia a distancia de 17,4% y 19,4%, respectivamente (p = 0,36); tasas de recurrencia local de 3,2% y 3,5%, respectivamente (p = 0,36); y la mediana de las tasas de supervivencia global de 61 y 60,5 meses, respectivamente (p = 0,8). No se observó una correlación estadísticamente significativa de mejoría en los resultados con dosis de radiación superiores a 5040 cGy.LIMITACIONES:Este es un estudio retrospectivo.CONCLUSIONES:Nuestro estudio mostró que el aumento de la dosis más allá de la dosis estándar de 4500-5040cGy no logró resultados clínicos significativos. Consulte Video Resumen en http://links.lww.com/DCR/B633. (Traducción-Dr. Gunther Bocic).

The Impact of Neoadjuvant Chemotherapy on the Surgical Management of Colorectal Peritoneal Metastases: A Systematic Review and Meta-Analysis

Background

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is a well-recognised treatment option for the management of colorectal peritoneal metastases (CRPM). However, incorporating the routine use of neoadjuvant chemotherapy (NAC) into this management plan is controversial.

Methods

A systematic review and meta-analysis were conducted to evaluate the impact of neoadjuvant chemotherapy on perioperative morbidity and mortality, and long-term survival of patients with CRPM undergoing CRS and HIPEC.

Results

Twelve studies met the inclusion criteria (n = 2,463 patients). Ten were retrospective cohort, one was prospective cohort, and one was a prospective randomised by design. Patients who received NAC followed by CRS and HIPEC experienced no difference in major perioperative morbidity and mortality compared with patients who underwent surgery first (SF). There was no difference in overall survival at 3 years, but at 5 years NAC patients had superior survival (relative risk [RR] 1.31; 95% confidence interval [CI] 1.11–1.54, P < 0.001). There were no differences in 1- and 3-year, disease-free survival (DFS) between groups. Study heterogeneity was generally high across all outcome measures.

Conclusions

Patients who received neoadjuvant chemotherapy did not experience any increase in perioperative morbidity or mortality. The potential improvement in 5-year overall survival in patients receiving NAC is based on limited confidence due to several limitations in the data, but not sufficiently enough to curtail its use. The practice of NAC in this setting will remain heterogeneous and guided by retrospective evidence until prospective, randomised data are reported.

Long-Term Outcome in a Phase II Study of Regional Hyperthermia Added to Preoperative Radiochemotherapy in Locally Advanced and Recurrent Rectal Adenocarcinomas

Hyperthermia was added to standard preoperative chemoradiation for rectal adenocarcinomas in a phase II study. Patients with T3-4 N0-2 M0 rectal cancer or local recurrences were included. Radiation dose was 54 Gy combined with capecitabine 825 mg/m2 × 2 daily and once weekly oxaliplatin 55 mg/m2. Regional hyperthermia aimed at 41.5–42.5 °C for 60 min combined with oxaliplatin infusion. Radical surgery with total or extended TME technique, was scheduled at 6–8 weeks after radiation. From April 2003 to April 2008, a total of 49 eligible patients were recruited. Median number of hyperthermia sessions were 5.4. A total of 47 out of 49 patients (96%) had the scheduled surgery, which was clinically radical in 44 patients. Complete tumour regression occurred in 29.8% of the patients who also exhibited statistically significantly better RFS and CSS. Rate of local recurrence alone at 10 years was 9.1%, distant metastases alone occurred in 25.6%, including local recurrences 40.4%. RFS for all patients was 54.8% after 5 years and CSS was 73.5%. Patients with T50 temperatures in tumours above median 39.9 °C had better RFS, 66.7% vs. 31.3%, p = 0.047, indicating a role of hyperthermia. Toxicity was acceptable.

Biomarkers in Locally Advanced Rectal Cancer: A Review

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

Preoperative assessment and optimisation for pelvic exenteration in locally advanced and recurrent rectal cancer: A review

The pre-operative phase in planning a pelvic exenteration or extended resections is critical to optimising patient outcomes. This review summarises the key components of preoperative assessment and planning in patients with locally advanced rectal cancer (LARC) and locally recurrent rectal cancer (LLRC) being considered for potential curative resection. The preoperative period can be considered in 5 key phases: 1) Multidisciplinary meeting (MDT) review and recommendation for neoadjuvant therapy and surgery, 2) Anaesthetic preoperative assessment of fitness for surgery and quantification of risk, 3) Shared decision making with the patient and the process of informed consent, 4) Prehabilitation and physiological optimisation 5) Technical aspects of surgical planning. This review will focus on patients who have been recommended for surgery by the MDT and have completed neoadjuvant therapy. Other important considerations beyond the scope of this review are the various neoadjuvant strategies employed which in this patient group include Total Neo-adjuvant Therapy and reirradiation. Critical to improving perioperative outcomes is the dual aim of achieving a negative resection margin in a patient fit enough for extended surgery. Advanced, realistic communication is required pre-operatively and should be maintained throughout recovery. Optimising patient's physiological and psychological reserve with a preoperative prehabilitation programme is important, with physiotherapy, psychological and nutritional input. From a surgical perspective, image based technical preoperative planning is important to identify risk points and ensure correct surgical strategy. Careful attention to the entire patient journey through these 5 preoperative phases can optimise outcomes with the accumulation of marginal gains at multiple timepoints.

CA724 Predicts Tumor Regression Grade in Locally Advanced Gastric Cancer Patients with Neoadjuvant Chemotherapy

Purpose: Tumor regression grade (TRG) is widely used to evaluate the efficacy of neoadjuvant chemotherapy (NCT) and it is related to many clinicopathological factors. However, whether TRG can be predicted by clinical characteristics is unknown.

Methods: 141 locally advanced gastric cancer (GC) patients who underwent NCT and curative operation were retrospectively analyzed. TRG is reevaluated according to the CAP guideline. The values of CA199, CA125 and CA724 before NCT (pre-) and after NCT (post-) were extracted from our database. Survival curves on overall survival (OS) were obtained by Kaplan-Meier method, and differences were analyzed by log-rank test. Associations between categorical variables were explored by chi-square test or Fisher's exact method. Univariable and multivariate analyses were performed by logistic regression model or Cox proportional hazard regression model.

Results: TRG was related to OS (P < 0.001), especially when divided into responders (TRG 0-1) and non-responders (TRG 2-3). Pre-CA724 (p = 0.029) and post-CA199 (p = 0.038) were related to OS. In multivariable analysis, pre-CA724 (p = 0.015) and post-CA199 (p = 0.007) were independent prognostic factors for OS, respectively. The changes (diff-) of all tumor markers were not related to OS. Among the clinical characteristics, pre-CA724 (P = 0.047) and tumor size (P = 0.012) were related to TRG, while pre-CA199 (P = 0.377) and pre-CA125 (P = 0.856) were not. In logistics analysis, pre-CA724 (P = 0.032), tumor size (P = 0.011) and tumor location (P = 0.047) were independent risk factors to pathological response.

Conclusion: CA724 was an independent prognostic factor for OS and could be used to predict pathological response.

The predictive value of PET/CT for distant recurrences in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

INTRODUCTION

It is well recognized that pathological complete response (pCR) for locally advanced rectal cancer after neoadjuvant chemoradiotherapy (CRT) confers a positive survival advantage. Despite this, a small proportion of patients can develop distant recurrence, and these are the patients that will likely benefit from adjuvant therapy. This study aims to investigate the role of PET/CT as a functional imaging to stratify patients according to their risk of distant recurrence.

METHODS

This is a retrospective analysis of a prospectively maintained database in a single quaternary teaching hospital from 2010 to 2019. All consecutive cases of locally advanced rectal cancer with restaging PET/CT were included. The primary outcome measure was 5-year OS and distant recurrence-free survival.

RESULTS

A pCR and complete metabolic response (CMR) were identified in 47 (18%) patients and 73 (27.4%) patients respectively. Of these, 26 patients had both pCR and CMR and these patients remained free of local and distant recurrence at their last censored date. Patients with both pCR and CMR achieved the highest 5-year overall survival of 96.2%, followed by those with pCR and incomplete CMR (iCMR) of 85.7%, non-pCR and CMR of 85.1% and non-pCR and iCMR of 83.1%. Independent predictors for 5-year distant recurrence-free survival were pathological and PET metabolic response, nodal staging and lymphovascular invasion (LVI).

CONCLUSION

In conclusion, a PET/CT has the potential to better stratify patients of their risk of distant metastasis. However, a larger validation cohort is required before these findings can be translated to clinical utility.

Watch and Wait Approach for Rectal Cancer Following Neoadjuvant Treatment: The Experience of a High Volume Cancer Center

Multimodal treatments for rectal cancer, along with significant research on predictors to response to therapy, have led to more conservative surgical strategies. We describe our experience of the rectal sparing approach in rectal cancer patients with clinical complete response (cCR) after neoadjuvant treatment. We also specifically highlight our clinical and imaging criteria to select patients for the watch and wait strategy (w&w). Data came from 39 out of 670 patients treated for locally advanced rectal cancer between January 2016 until February 2020. The selection criteria were a clinical complete response after neoadjuvant chemotherapy managed with a watch and wait (w&w) strategy. A strict follow-up period was adopted in these selected patients and follow-ups were performed every three months during the first two years and every six months after that. The median follow-up time was 28 months. Six patients had a local recurrence (15.3%); all were salvageable by total mesorectal excision (TME). Five patients had a distant metastasis (12.8%). There was no local unsalvageable disease after w&w strategy. The rectal sparing approach in patients with clinical complete response after neoadjuvant treatment is the best possible treatment and is appropriate to analyze from this perspective. The watch and wait approach after neoadjuvant treatment for rectal cancer can be successfully explored after inflexible and strict patient selection.

Development of a novel apoptosis-based tumor regression grade to assess the efficacy of preoperative chemoradiotherapy for rectal cancer: a retrospective single-center study

BACKGROUND

Preoperative chemoradiotherapy is used preferably for locally advanced rectal cancer, followed by a watch-and-wait strategy for cases showing clinical complete response. However, there is a discordance between pathological and clinical complete response rates. We aimed to propose a tumor regression grade (TRG) that truly reflects the therapeutic effects of preoperative chemoradiotherapy in locally advanced rectal cancer.

METHODS

Overall, 293 consecutive patients with T3/T4a/T4b rectal cancer who underwent chemoradiotherapy followed by radical surgery between Sep 2003 and Dec 2018 were retrospectively reviewed. We assessed apoptosis using M30 cytoDEATH immunostaining and correlated that with conventional TRG (convTRG) evaluated using hematoxylin-eosin staining, and created a new TRG by evaluating apoptosis and convTRG. The modified TRG1-4 (modifTRG) classification was as follows: modifTRG1 comprised poor TRG, modifTRG2 moderate TRG, modifTRG3 good TRG, modifTRG4 complete apoptosis and convTRG3 (pathological complete response). We assessed the overall survival, relapse-free survival, and local recurrence rate.

RESULTS

Pathological complete response rate was 10.6% when evaluated using conventional staining. Using M30 staining, apoptosis was observed in the residual disease in convTRG 1a 0%, convTRG 1b 0.3%, convTRG 2 9.2%. Combining the two, modifTRG4 was observed in 20.1%. The survival rates were similar between modifTRG4 and convTRG3, suggesting that modifTRG4 was equivalent to pathological complete response. However, in multivariate analysis, modifTRG but not convTRG was an independent risk factor for local and distant recurrences.

CONCLUSION

The proposed modifTRG truly reflected the therapeutic effects of chemoradiotherapy and may be superior to the convTRG to stratify rectal cancer patients treated with chemoradiotherapy.

Development and validation of an MRI-based radiomic nomogram to distinguish between good and poor responders in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy

PURPOSE

In the clinical management of patients with locally advanced rectal cancer (LARC), the early identification of poor and good responders after neoadjuvant chemoradiotherapy (N-CRT) is essential. Therefore, we developed and validated predictive models including MRI findings from the structured report template, clinical and radiomics parameters to differentiate between poor and good responders in patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy.

METHODS

Preoperative multiparametric MRI from 183 patients with locally advanced rectal cancer (122 in the training cohort, 61 in the validation cohort) was included in this retrospective study. After preprocessing, radiomic features were extracted and two methods of feature selection was applied to reduce the number of radiomics features. Logistic regression (LR) and random forest (RF) machine learning classifiers were trained to identify good responders from poor responders. Multivariable logistic regression analysis was used to incorporate the radiomic signature and clinical risk factors into a nomogram. Classifier performance was evaluated using the area under the curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

For the differentiation of poor and good responders, the radiomics model with an LR classifier achieved AUCs of 0.869 and 0.842 for the training and validation cohorts, respectively. The nomogram showed the highest reproducibility and prognostic ability in the training and validation cohorts, with AUCs of 0.923 (95% confidence interval, 0.872-0.975) and 0.898 (0.819-0.978), respectively. Additionally, the nomogram achieved significant risk stratification of patients in respect to progression free survival (PFS).

CONCLUSIONS

The nomogram accurately differentiated good and poor responders in patients with LARC undergoing N-CRT, and showed significant performance for predicting PFS.

Prognostic importance of circumferential resection margin in the era of evolving surgical and multidisciplinary treatment of rectal cancer: A systematic review and meta-analysis

BACKGROUND

Circumferential resection margin is considered an important prognostic parameter after rectal cancer surgery, but its impact might have changed because of improved surgical quality and tailored multimodality treatment. The aim of this systematic review was to determine the prognostic importance of circumferential resection margin involvement based on the most recent literature.

METHODS

A systematic literature search of MEDLINE, Embase, and the Cochrane Library was performed for studies published between January 2006 and May 2019. Studies were included if 3- or 5-year oncological outcomes were reported depending on circumferential resection margin status. Outcome parameters were local recurrence, overall survival, disease-free survival, and distant metastasis rate. The Newcastle Ottawa Scale and Jadad score were used for quality assessment of the studies. Meta-analysis was performed using a random effects model and reported as a pooled odds ratio or hazard ratio with 95% confidence interval.

RESULTS

Seventy-five studies were included, comprising a total of 85,048 rectal cancer patients. Significant associations between circumferential resection margin involvement and all long-term outcome parameters were uniformly found, with varying odds ratios and hazard ratios depending on circumferential resection margin definition (<1 mm, ≤1 mm, otherwise), neoadjuvant treatment, study period, and geographical origin of the studies.

CONCLUSION

Circumferential resection margin involvement has remained an independent, poor prognostic factor for local recurrence and survival in most recent literature, indicating that circumferential resection margin status can still be used as a short-term surrogate endpoint.

Lymph Node Regression to Neoadjuvant Chemoradiotherapy in Patients with Locally Advanced Rectal Cancer: Prognostic Implication and a Predictive Model

AIM

Currently, few studies have focused on the prognostic impact of lymph node regression to neoadjuvant chemoradiotherapy (NCRT) in rectal cancer. This study aimed to explore the prognostic impact of lymph node regression grade (LRG) in patients with locally advanced rectal cancer (LARC) following NCRT and radical surgery and develop a predictive nomogram for disease-free survival (DFS).

METHODS

LARC patients undergoing NCRT and radical surgery between 2013 and 2014 were enrolled and divided into LRG low (≤ 2), middle (3-9), and high (≥ 10) groups. Clinicopathological characteristics and survival outcomes were compared. Predictors for DFS were identified by Cox regression analysis, and a nomogram was constructed.

RESULTS

A total of 257 LARC patients were eligible, including LRG low (n = 149), middle (n = 59), and high (n = 49) groups. Higher LRG score was associated with higher TRG, more advanced ypT and ypN stages, and poorer OS and DFS (all P < 0.001). Cox regression analysis demonstrated that tumor differentiation (poor and anaplastic, HR = 2.048, P = 0.048), ypTNM stage (HR = 2.389, P = 0.015), and LRG-sum (HR = 1.020, P = 0.029) were independent prognostic determinants for DFS after NCRT. A nomogram for DFS was developed with a C-index of 0.68 (95%CI 0.64-0.72).

CONCLUSION

LRG is an important prognostic indicator for DFS in LARC patients after NCRT. A predictive nomogram based on LRG was developed to guide more tailored adjuvant treatment and surveillance.

Predicting pathological response to chemoradiotherapy for rectal cancer: a systematic review

Introduction: Pathological complete response (pCR) rates of approximately 20% following neoadjuvant long-course chemoradiotherapy for rectal cancer have given rise to non-operative or watch-and-wait (W&W) management. To improve outcomes there has been significant research into predictors of response. The goal is to optimize selection for W&W, avoid chemoradiotherapy in those who won't benefit and improve treatment to maximize the clinical complete response (cCR) rate and the number of patients who can be considered for W&W.Areas covered: A systematic review of articles published 2008-2018 and indexed in PubMed, Embase or Medline was performed to identify predictors of pathological response (including pCR and recognized tumor regression grades) to fluoropyrimidine-based chemoradiotherapy in patients who underwent total mesorectal excision for rectal cancer. Evidence for clinical, biomarker and radiological predictors is discussed as well as potential future directions.Expert opinion: Our current ability to predict the response to chemoradiotherapy for rectal cancer is very limited. cCR of 40% has been achieved with total neoadjuvant therapy. If neoadjuvant treatment for rectal cancer continues to improve it is possible that the treatment for rectal cancer may eventually parallel that of anal squamous cell carcinoma, with surgery reserved for the minority of patients who don't respond to chemoradiotherapy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

BMI May Be a Prognostic Factor for Local Advanced Rectal Cancer Patients Treated with Long-Term Neoadjuvant Chemoradiotherapy

OBJECTIVE

This study aims to develop feasible nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of the local advanced rectal cancer (LARC) patients who were treated with neoadjuvant chemoradiotherapy (nCRT) and operation.

METHODS

A total of 243 LARC patients undergoing nCRT followed by total mesorectal excision (TME) were enrolled. Preoperative clinical features and postoperative pathological characteristics were collected. A Cox regression analysis was performed, and Cox-based nomograms were developed to predict the OS and CSS. We assessed the predictive performance of the nomogram with concordance index and calibration plots.

RESULTS

A total of 243 patients were included with a median follow-up period of 46 months (range from 9 to 86 months). Cox regression analysis showed that low BMI (BMI < 18.5, HR= 21.739, P < 0.05), high level of preoperative CA19-9 (HR = 3.369, P = 0.036), high ypStage (HR = 19.768, P < 0.001), positive neural invasion (HR = 4.218, P = 0.026) and no adjuvant chemotherapy (HR = 5.495, P < 0.001) were independent predictors of poor OS. Age ≥70 (HR = 2.284, P <0.001), low BMI (BMI < 18.5, HR = 3.906, P < 0.05), positive preoperative CA19-9 (HR = 1.920, P = 0.012), high ypStage (HR = 5.147, P <0.001) and positive neural invasion (HR = 2.873, P = 0.022) were independent predictors of poor CSS. The predictive nomograms were developed to predict the OS and CSS with a C-index of 0.837 and 0.760. Good statistical performance on internal validation was shown by calibration plots.

CONCLUSION

In conclusion, this study demonstrated that BMI was an independent prognostic factor for OS and CSS in LARC patients treated with nCRT followed TME. A nomogram incorporating BMI, neural invasion, pre-CA19-9, ypStage, age, and adjuvant chemotherapy could be helpful to predict the OS and CSS.

Evaluation and Comparison of Predictive Value of Tumor Regression Grades according to Mandard and Becker in Locally Advanced Gastric Adenocarcinoma

Purpose

Tumor regression grade (TRG) has been widely used in gastrointestinal carcinoma to assess pathological responses to neoadjuvant chemotherapy (NCT). There are various standards without a consensus, and it is still unclear which kind of system has better predictive value. This study aims to investigate and compare the predictive ability of the Mandard and Becker TRGs in patients with locally advanced gastric cancer.

Materials and Methods

A total of 290 patients with locally advanced gastric adenocarcinoma who underwent NCT and curative surgery were studied. Survival analysis for overall survival (OS) and disease-free survival (DFS) were based on the Kaplan-Meier method and Cox proportional hazards method. Predictive values of TRGs and models were assessed by time-dependent receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), nomogram, and calibration curve.

Results

In multivariable analysis, the Mandard TRG was associated with OS (hazard ratio [HR], 1.806; p=0.026) and DFS (HR, 1.792; p=0.017). The Becker TRG was also related to OS (HR, 1.880; p=0.014) and DFS (HR, 1.919; p=0.006). The Mandard and Becker TRG AUCs for 5-year survival were 0.72 and 0.71, respectively. The whole models showed an increased predictive value, with AUCs of 0.85 and 0.86, respectively. There was no significant difference between the two TRGs and two models.

Conclusion

TRG was an independent predictor for survival, and there was no significant difference between these two systems.

Pre-Treatment T2-WI Based Radiomics Features for Prediction of Locally Advanced Rectal Cancer Non-Response to Neoadjuvant Chemoradiotherapy: A Preliminary Study

Locally advanced rectal cancer (LARC) response to neoadjuvant chemoradiotherapy (nCRT) is very heterogeneous and up to 30% of patients are considered non-responders, presenting no tumor regression after nCRT. This study aimed to determine the ability of pre-treatment T2-weighted based radiomics features to predict LARC non-responders. A total of 67 LARC patients who underwent a pre-treatment MRI followed by nCRT and total mesorectal excision were assigned into training (n = 44) and validation (n = 23) groups. In both datasets, the patients were categorized according to the Ryan tumor regression grade (TRG) system into non-responders (TRG = 3) and responders (TRG 1 and 2). We extracted 960 radiomic features/patient from pre-treatment T2-weighted images. After a three-step feature selection process, including LASSO regression analysis, we built a radiomics score with seven radiomics features. This score was significantly higher among non-responders in both training and validation sets (p < 0.001 and p = 0.03) and it showed good predictive performance for LARC non-response, achieving an area under the curve (AUC) = 0.94 (95% CI: 0.82–0.99) in the training set and AUC = 0.80 (95% CI: 0.58–0.94) in the validation group. The multivariate analysis identified the radiomics score as an independent predictor for the tumor non-response (OR = 6.52, 95% CI: 1.87–22.72). Our results indicate that MRI radiomics features could be considered as potential imaging biomarkers for early prediction of LARC non-response to neoadjuvant treatment.

Connection and distinction of tumor regression grading systems of gastrointestinal cancer

OBJECTIVES

As the neoadjuvant therapy has been successfully introduced in the treatment of gastrointestinal malignancies, the evaluation of therapeutic effectiveness is becoming increasingly important. Tumor-node-metastasis system has been widely applied. However, this system is mainly based on the location of residual tumor, but does not consider the amount of residual tumor. Tumor regression grading system, a quantitative method to assess the reaction of tumor to neoadjuvant treatment, could be used as a supplement to tumor-node-metastasis system and provide additional information on prognosis. To date, numerous gastrointestinal grading systems have been used in esophageal/esophagogastric junction carcinoma, gastric adenocarcinoma, colorectal cancer, and most of them were considered to associate with clinical outcomes.

MATERIALS AND METHODS

In this review, firstly, we expounded the importance of tumor regression grading systems, and summarized the histopathological changes after neoadjuvant therapy. Secondly, we introduced some commonly used gastrointestinal systems, as well as the relationships and nuance. Finally, we discussed pivotal issues about these systems. In this part, we explained the calculation methods based on grid points and square measures, discussed several factors leading to observer bias, containing the slice number and the grading tier number, and analyzed the factors that might affect clinical significance, covering anatomical location, the selection of survival index, and the tumor type.

RESULTS

Tumor regression grade systems could be divided into two main classifications, the relative amount of fibrosis and residual tumor, and the proportion of residual tumor in the tumor bed. However, the definitions of these systems were still need to be improved.

CONCLUSIONS

The tumor regression grading system is useful in evaluating tumor response to neoadjuvant therapy, but more work is needed to refine and unify the system.

The effect of radiotherapy on rectal cancer: a histopathological appraisal and prognostic indicators

The management of rectal cancer is a major undertaking. There are currently multiple treatment modalities with variable degrees of complications. Radiotherapy (RT) is one of the more frequently used modalities either on its own or more frequently with chemotherapy mostly before the definitive surgery. The outcome of RT is unpredictable. RT has its serious side effects and there are no guarantees of its usefulness in all patients. This article outlines the effect of RT on the tumor, reviews the various staging systems of responses to RT and present recent evidence of which case is less responsive to such treatments to avoid unnecessary complications.

Perineural invasion is associated with poor prognosis of colorectal cancer: a retrospective cohort study

PURPOSE

Perineural invasion (PNI) is associated with poor prognosis in a variety of cancers. Our aim was to determine the clinicopathological factors associated with PNI in colorectal cancer (CRC) and its impact on patient survival.

MATERIAL AND METHODS

The clinical data of 1412 patients diagnosed with CRC from July 2013 to July 2016 were retrospectively collected. PNI was determined based on hematoxylin-eosin staining. The relationships of PNI with various clinicopathological factors and prognosis were analyzed.

RESULTS

The incidence of PNI in the entire cohort was 21.5%. PNI was significantly more common in patients with lower tumor differentiation, higher tumor stage, vascular invasion, TNM stage, tumor diameter, MMR/KRAS/NRAS/BRAF mutation, and more positive lymph nodes. Logistic regression analysis showed that T stage, vascular invasion, tumor diameter, and MMR were the main influencing factors of PNI. Cox regression analysis showed that poor tumor differentiation, N stage, TNM stage, PNI, and BRAF status were independent prognostic factors for OS. The OS, CSS, and PFS rate of the PNI (-) group was higher than that of the PNI (+) group, and the difference was statistically significant (P < 0.001).

CONCLUSION

PNI in patients with colorectal cancer is significantly associated with T stage, TNM stage, vessel invasion, tumor diameter, MMR status, and BRAF mutation. PNI status is an independent prognostic factor for CRC. Assessing the postoperative PNI status may help predict prognosis and determine further treatment options for these patients.

Interobserver Variability in Assessing Pathologic Response to Preoperative Treatment in Rectal Cancer: Standardization of an Evaluation Method and Comparisons Between Published Scales

BACKGROUND

Evaluating tumor response of rectal cancer to preoperative chemoradiotherapy (NCRT) has a prognostic value on overall survival; however, grading tumor response is a controversial issue due to lack of reproducibility and the lack of information about the standardization of the evaluation.

METHODS

We performed this study to examine the variability between observers' assessment of the pathological responses to NCRT using a systematic quantitative grading system based on a percentage of tumor response against the proportion of residual tumor burden. As a secondary aim, we classified the tumor response according to six published systems to determine the correlation between the observers into each grading system.

RESULTS

From 70 cases, the mean age was 60.6 ± 11.78 years, 36 (51.47%) patients were female, the pathological T stage was pT3 in 48.6% of cases, pT2 in 32.9%, pT1 in 11.4% and 7.1% in pT4, whereas 40% had lymph node metastasis. The median lymph node count was ten lymph nodes (range 6-43). Our method of tumor regression evaluation has a good intraclass correlation (ICC) value. From the scales compared regarding interobserver agreement, the Ryan's and Royal College of Pathologists showed fair agreement (but good ICC); the scales from Dworak, Becker, and Rizk showed substantial agreement (and good to excellent ICC values); and the scale from Rödel showed almost-perfect agreement.

RESULTS

All the evaluated systems showed good interobserver agreement, but the best interobserver agreement was reached with the Rödel's scale.

MicroRNAs in Colon and Rectal Cancer - Novel Biomarkers from Diagnosis to Therapy

Colorectal cancer (CRC) is one of the most common cancers and a significant cause of tumor- related deaths worldwide. Traditional biomarkers, such as CEA and CA199, are not sensitive enough to provide useful information for early diagnosis and treatment and are rather used to track the clinical progression of the disease. There is growing evidence that microRNAs (miRNA) are potentially superior to traditional biomarkers as promising non-invasive biomarkers for the timely diagnosis and prediction of prognosis or treatment response in the management of CRC. In this review, the latest studies on the dysregulation of miRNAs expression in CRC and the potential for miRNAs to serve as biomarkers were collected. Given the limitations of miRNA, as discussed in this paper, its clinical applications as a diagnostic biomarker should be limited to use in combination with other biomarkers. Further research is necessary to elucidate the clinical applications of miRNA in therapy for CRC.

Prognostic Significance of Clinicopathological and Molecular Features After Neoadjuvant Chemoradiotherapy in Rectal Cancer Patients

BACKGROUND/AIM

This study evaluated clinicopathological and molecular features and their prognostic impact on patients with locally advanced rectal cancer (LARC) who received preoperative chemoradiotherapy (CRT).

PATIENTS AND METHODS

We retrospectively gathered data from 284 patients with LARC who underwent total mesorectal excision (TME) after CRT.

RESULTS

In the univariate analysis, lower yield pathologic T (ypT) category, yield pathologic N (ypN) category, yield pathologic TNM (ypTNM) stage, as well as the absence of lymphovascular invasion (LVI) and perineural invasion (PNI), were significantly associated with better disease-free survival (DFS) and overall survival (OS). Meanwhile, the expression of Ki-67, p53, and the mismatch repair (MMR) status showed no association with clinical outcomes. A multivariate survival analysis revealed that ypT category and LVI were independent prognostic factors of a worse DFS (HR=3.081, p-value=0.001; HR=2.818, p-value=0.030) and OS (HR=3.158, p-value=0.006; HR=3.837, p-value=0.014).

CONCLUSION

The ypT category and the presence of LVI were found to be prognostic factors for patients with LARC after CRT followed by TME.

YpN0 rectal cancer patients with sterilized lymph nodes after neoadjuvant chemoradiotherapy are of greater risk of recurrence

BACKGROUND

Indication for adjuvant chemotherapy in ypN0 rectal cancer patients after chemoradiotherapy (CRT) is debated. The clinical significance of the presence of sterilized lymph nodes (LNS) in ypN0 patients remains to be determined.

AIMS

To assess the prognostic value of LNS in ypN0 rectal cancers after neoadjuvant CRT.

METHODS

From 2006-2016, 235 patients underwent TME surgery for non-metastatic mid-low rectal cancer after CRT. A lymph node was considered sterilized if there were signs of treatment response (fibrosis, necrosis or mucus) without residual tumor cells.

RESULTS

180 patients (77%) were classified ypN0 and 55 (23%) ypN+. LNS was present in 20 patients (9%). In ypN0 patients, 5-year OS was similar between patients with and without LNS. In contrast, 5-year DFS was significantly lower in ypN0/LNS + patients (58% vs. 78%, p = 0.043) and was similar to those staged ypN+. In multivariate analysis, two factors were independent predictors of DFS: mesorectal grading (OR = 3.14; 95%CI: 1.10-8.34; p = 0.033) and the presence of LNS (OR = 3.93, 95% CI: 1.06-11.81, p = 0.042) CONCLUSION: The presence of LNS in ypN0 rectal cancer after neoadjuvant CRT is associated with an increased risk of recurrence and may be taken into account for the discussion of adjuvant chemotherapy.

Impact of delaying surgery after chemoradiation in rectal cancer: outcomes from a tertiary cancer centre in India

BACKGROUND

Delaying surgery after chemoradiation is one of the strategies for increasing tumor regression in rectal cancer. Tumour regression and PCR are known to have positive impact on survival.

METHODS

It's a retrospective study of 161 patients undergoing surgery after neoadjuvant chemoradiation (NCRT) for locally advanced rectal cancer (LARC). Patients were divided into three categories based on the gap between NCRT and surgery, i.e., <8, 8-12 and >12 weeks. Tumor regression grades (TRG), sphincter preservation, post-operative morbidity-mortality and survival were evaluated.

RESULTS

Sphincter preservation was significantly less in >12 weeks group compared to the other two groups (P=0.003). Intraoperative blood loss was significantly higher in >12 weeks group compared to 8-12 weeks group (P=0.001).There was no difference in major postoperative morbidity and hospital stay among the groups. There was no significant correlation between delay and TRG (P=0.644). At Median follow up of 49.5 months the projected 3-year overall survival (OS) and disease free survival (DFS) were not significantly different among the 3 groups (OS: 79.5% vs. 83.3% vs. 76.5%; P=0.849 and DFS 50.4% vs. 70.6% vs. 62%; P=0.270 respectively).

CONCLUSIONS

Delaying surgery by more than 12 weeks causes more blood loss but no change in morbidity or hospital stay. Increased time interval between radiation and surgery does not improve tumor regression and has no effect on survival.

Importance of the neoadjuvant rectal (NAR) score to the outcome of neoadjuvant chemotherapy alone for locally advanced rectal cancer

PURPOSE

The neoadjuvant rectal (NAR) score is a promising indicator of survival after preoperative chemoradiotherapy for rectal cancer. However, its effectiveness after neoadjuvant chemotherapy (NAC) alone has not been fully investigated.

METHODS

We analyzed data retrospectively on 61 patients with rectal cancer, who received NAC followed by surgical resection between 2010 and 2015, and evaluated the impact of the NAR score on survival.

RESULTS

The median NAR score was 14.9. Of the 61 patients, 13, 35, and 13 were classified as having NAR-low (< 8), NAR-intermediate (8-16), and NAR-high (> 16) scores, respectively. The median observation period was 49.0 months. According to the NAR score, the 3-year DFS in the NAR-low group was 100%, which was significantly better than that in the NAR-intermediate (64.8%, p = 0.041), and NAR-high (61.5%, p = 0.018) groups. When the NAR-intermediate and NAR-high groups were investigated as a single high-risk group, the 3-year DFS of the patients who received adjuvant chemotherapy was 88.7%, which was significantly better than that of the patients who did not receive adjuvant chemotherapy (53.3%, p = 0.042).

CONCLUSIONS

The NAR score may predict the DFS and could serve as a favorable indicator of adjuvant chemotherapy after NAC alone.

MRI for Restaging Locally Advanced Rectal Cancer: Detailed Analysis of Discrepancies With the Pathologic Reference Standard

OBJECTIVE. The purpose of this study was to analyze causes of discrepancies between restaging MRI and pathologic findings in the assessment of morphologic indicators of tumor response in patients with rectal cancer who have undergone neoadjuvant treatment. MATERIALS AND METHODS. MRI and pathologic data from 57 consecutively registered patients who underwent neoadjuvant treatment and total mesorectal excision between August 2015 and July 2018 were retrospectively analyzed. The sensitivity and specificity of restaging MRI in determining tumor regression grade, T category, N category, circumferential resection margin, and extramural vascular invasion were calculated with pathologic results as the reference standard. One-by-one comparisons between MRI and pathologic findings were conducted to identify causes of discrepancies. RESULTS. The sensitivity of MRI in determining tumor regression grades 3-5 was 77.1%; T3 and T4 category, 100.0%; node-positive disease, 75.0%; circumferential resection margin, 87.5%; and extramural vascular invasion, 91.7%. The specificity values were 72.7%, 62.5%, 70.7%, 85.7%, and 64.4%. Overstaging was mainly caused by misinterpretation of fibrotic areas as residual tumor. Inflammatory cell infiltration could appear as high signal intensity in fibrotic areas on DW images, an appearance similar to that of residual tumor. Edematous mucosa and submucosa adjacent to the tumor and muscularis propria could also be mistaken for residual tumor because of their intermediate signal intensity on T2-weighted MR images. CONCLUSION. MRI was prone to overstaging of disease. Discrepancies between MRI and pathologic findings were mainly caused by misinterpretation of fibrosis. Inflammatory cell infiltration, pure mucin, edematous mucosa and submucosa adjacent to the tumor, and muscularis propria could also be misinterpreted as residual tumor.

Impact of single-nucleotide polymorphisms in DNA repair pathway genes on response to chemoradiotherapy in rectal cancer patients: Results from ACCORD-12/PRODIGE-2 phase III trial

We examined whether 66 germline single-nucleotide polymorphisms (SNPs) in 10 candidate genes would predict clinical outcome in 316 patients with resectable locally advanced rectal cancer (LARC) enrolled in the ACCORD-12 phase III trial who were randomly treated with preoperative radiotherapy plus capecitabine (CAP45; n = 155) or dose-intensified radiotherapy plus capecitabine and oxaliplatin (CAPOX50; n = 161). The primary endpoint was tumor response according to the Dworak score. Multivariate logistic regression models adjusted on treatment arm and T stage determined the SNPs prognostic and predictive values for tumor response. In univariate analysis, five SNPs in ERCC2, XPA, MTHFR and ERCC1 were associated with the Dworak score in the CAPOX50 arm. In the overall population, interaction with treatment arm was significant for ERCC2 rs1799787 (p_interaction = 0.05) and XPA rs3176683 (p_interaction = 0.008), suggesting a predictive effect for response to oxaliplatin-based chemoradiotherapy (CRT). All but XPA rs3176683 had a prognostic effect on tumor response. In a multivariate model, interaction remained significant for XPA rs3176683 ([OR 7.33, 95% CI 1.40-38.23], p_interaction = 0.018) and the prognostic effect significant for ERCC2 rs1799787 ([OR 0.55, 95%CI 0.32-0.93], p = 0.027) and ERCC1 rs10412761 ([OR 0.57, 95%CI 0.34-0.98], p = 0.042). Patients with the T/G haplotype of rs1799787 and rs10412761 had a 60% decrease in odds of response (p < 0.001). None of the five SNPs were associated with toxicity, overall and disease-free survival. These data suggest that genetic variation in DNA repair genes influences response to preoperative CRT in LARC and identify patients who benefit from the addition of oxaliplatin to CRT.

Impact of Tumor Regression Grade as a Major Prognostic Factor in Locally Advanced Rectal Cancer after Neoadjuvant Chemoradiotherapy: A Proposal for a Modified Staging System

There is ongoing debate regarding the significance of complete or near-complete response after neoadjuvant chemoradiotherapy (CRT) for rectal cancer. This study assessed the prognostic value of the Dworak tumor regression grade (TRG) following neoadjuvant CRT and surgery primarily in patients with pathological stage (ypStage) II and III rectal cancer. The records of 331 patients who underwent neoadjuvant CRT followed by total mesorectal excision between 2004 and 2015 were retrospectively reviewed. Patients were categorized as having a good response (GR, TRG 3/4, n = 122) or a poor response (PR, TRG 1/2, n = 209). At a median follow-up of 65 months, five-year disease-free survival (DFS) was higher in the GR group than in the PR group (91.3% vs. 66.6%, p < 0.001). Patients with a GR and ypStage II disease had a five-year DFS that was indistinguishable from that of patients with ypStage 0–I disease (92.3% vs. 90.7%, p = 0.885). Likewise, patients with a GR and ypStage III disease had a five-year DFS similar to those with ypStage II disease (76.0% vs. 75.9%, p = 0.789). A new modified staging system that incorporates grouped TRG (GR vs. PR) was developed. The prognostic performance of this modified stage and the ypStage was compared with the Harrell C statistic. C statistic of the modified stage was higher than that of the ypStage (0.784 vs. 0.757, p = 0.012). The results remained robust after multivariate Cox regression analyses. In conclusion, a GR to neoadjuvant CRT is an independent predictor of good DFS and overall survival and further stratifies patients so as to estimate the risk of recurrence and survival among patients with ypStage II and III rectal cancer.