T-level downstaging and complete pathologic response after preoperative chemoradiation for advanced rectal cancer result in decreased recurrence and improved disease-free survival

Stage IV Rectal Cancer and Timing of Surgical Approach

Liver metastases are seen in at least 60% of patients with colorectal cancer at some point during the course of their disease. The management of both primary and liver disease is uniquely challenging in rectal cancer due to competing treatments and complex sequence of treatments depending on the clinical presentation of disease. Recently, several novel concepts are shaping new treatment paradigms, including changes in timing, sequence, and duration of therapies combined with potential deescalation of treatment components. Overall, the treatment of this clinical scenario mandates multidisciplinary evaluation and personalization of care; however, there is still considerable debate regarding the timing of liver metastasectomy in the context of the overall treatment plan. Herein, we will discuss the current literature on management of rectal cancer with synchronous liver metastasis, current treatment approaches with respect to chemotherapy, and role of hepatic artery infusion therapy.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prediction of locally advanced rectal cancer response to neoadjuvant chemoradiation therapy using volumetric multiparametric MRI-based radiomics

PURPOSE

To assess the role of pretreatment multiparametric (mp)MRI-based radiomic features in predicting pathologic complete response (pCR) of locally advanced rectal cancer (LARC) to neoadjuvant chemoradiation therapy (nCRT).

METHODS

This was a retrospective dual-center study including 98 patients (M/F 77/21, mean age 60 years) with LARC who underwent pretreatment mpMRI followed by nCRT and total mesorectal excision or watch and wait. Fifty-eight patients from institution 1 constituted the training set and 40 from institution 2 the validation set. Manual segmentation using volumes of interest was performed on T1WI pre-/post-contrast, T2WI and diffusion-weighted imaging (DWI) sequences. Demographic information and serum carcinoembryonic antigen (CEA) levels were collected. Shape, 1st and 2nd order radiomic features were extracted and entered in models based on principal component analysis used to predict pCR. The best model was obtained using a k-fold cross-validation method on the training set, and AUC, sensitivity and specificity for prediction of pCR were calculated on the validation set.

RESULTS

Stage distribution was T3 (n = 79) or T4 (n = 19). Overall, 16 (16.3%) patients achieved pCR. Demographics, MRI TNM stage, and CEA were not predictive of pCR (p range 0.59-0.96), while several radiomic models achieved high diagnostic performance for prediction of pCR (in the validation set), with AUCs ranging from 0.7 to 0.9, with the best model based on high b-value DWI demonstrating AUC of 0.9 [95% confidence intervals: 0.67, 1], sensitivity of 100% [100%, 100%], and specificity of 81% [66%, 96%].

CONCLUSION

Radiomic models obtained from pre-treatment MRI show good to excellent performance for the prediction of pCR in patients with LARC, superior to clinical parameters and CEA. A larger study is needed for confirmation of these results.

Factors Associated With Racial and Ethnic Disparities in Locally Advanced Rectal Cancer Outcomes

Importance

Hispanic and non-Hispanic Black patients receiving neoadjuvant therapy and surgery for locally advanced rectal cancer (LARC) achieve less favorable clinical outcomes than non-Hispanic White patients, but the source of this disparity is incompletely understood.

Objective

To assess whether racial and ethnic disparities in treatment outcomes among patients with LARC could be accounted for by social determinants of health and demographic, clinical, and pathologic factors known to be associated with treatment response.

Design, Setting, and Participants

The National Cancer Database was interrogated to identify patients with T3 to T4 or N1 to N2 LARC treated with neoadjuvant therapy and surgery. Patients were diagnosed between January 1, 2004, and December 31, 2017. Data were culled from the National Cancer Database from July 1, 2022, through December 31, 2023.

Exposure

Neoadjuvant therapy for rectal cancer followed by surgical resection.

Main Outcomes and Measures

The primary outcome was the rate of pathologic complete response (pCR) following neoadjuvant therapy. Secondary outcomes were rate of tumor downstaging and achievement of pN0 status.

Results

A total of 34 500 patient records were reviewed; 21 679 of the patients (62.8%) were men and 12 821 (37.2%) were women. The mean (SD) age at diagnosis was 59.7 (12.0) years. In terms of race and ethnicity, 2217 patients (6.4%) were Hispanic, 2843 (8.2%) were non-Hispanic Black, and 29 440 (85.3%) were non-Hispanic White. Hispanic patients achieved tumor downstaging (48.9% vs 51.8%; P = .01) and pN0 status (66.8% vs 68.8%; P = .02) less often than non-Hispanic White patients. Non-Hispanic Black race, but not Hispanic ethnicity, was associated with less tumor downstaging (odds ratio [OR], 0.86 [95% CI, 0.78-0.94]), less frequent pN0 status (OR, 0.91 [95% CI, 0.83-0.99]), and less frequent pCR (OR, 0.81 [95% CI, 0.72-0.92]). Other factors associated with reduced rate of pCR included rural location (OR, 0.80 [95% CI, 0.69-0.93]), lack of or inadequate insurance (OR for Medicaid, 0.86 [95% CI, 0.76-0.98]; OR for no insurance, 0.65 [95% CI, 0.54-0.78]), and treatment in a low-volume center (OR for first quartile, 0.73 [95% CI, 0.62-0.87]; OR for second quartile, 0.79 [95% CI, 0.70-0.90]; OR for third quartile, 0.86 [95% CI, 0.78-0.94]). Clinical and pathologic variables associated with a decreased pCR included higher tumor grade (OR, 0.58 [95% CI, 0.49-0.70]), advanced tumor stage (OR for T3, 0.56 [95% CI, 0.42-0.76]; OR for T4, 0.30 [95% CI, 0.22-0.42]), and lymph node-positive disease (OR for N1, 0.83 [95% CI, 0.77-0.89]; OR for N2, 0.73 [95% CI, 0.65-0.82]).

Conclusions and Relevance

The findings of this cohort study suggest that disparate treatment outcomes for Hispanic and non-Hispanic Black patients are likely multifactorial in origin. Future investigation into additional social determinants of health and biological variables is warranted.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

What Is the Comparative Efficacy of Surgical, Endoscopic, Transanal Resection, and Radiotherapy Modalities in the Treatment of Rectal Cancer?

BACKGROUND

Rectal cancer is a significant healthcare burden, and effective treatment is crucial. This research aims to compare the effectiveness of surgical and endoscopic resection, transanal resection, and radiotherapy.

METHODS

A literature analysis was conducted in order to identify relevant studies, by comparing the different surgical approaches and variables affecting treatment decisions. The findings were analyzed and synthesized to provide a comprehensive overview.

RESULTS

Surgical treatment, particularly TME (total mesorectal excision), proved consistent efficacy in achieving complete tumor resection and improving long-term survival. Endoscopic treatment and transanal resection techniques were promising for early-stage tumors but were associated with higher local recurrence rates. Radiotherapy, especially in combination with chemotherapy, played a crucial role in locally advanced cases, improving local control and reducing recurrence risk. Patient data, tumor characteristics, and healthcare system factors were identified as important factors in treatment modality selection.

CONCLUSION

Surgical treatment, specifically TME, remains the recommended standard approach for rectal cancer, providing excellent oncological outcomes. Endoscopic treatment and transanal resection techniques can be considered for selected early-stage cases, while radiotherapy is beneficial for locally advanced tumors. Treatment decisions should be personalized based on patient and tumor characteristics, considering the available resources and expertise within the healthcare system.

Evaluation of Predictive and Prognostic Importance of Lung Immune Prognostic Index in Locally Advanced Rectal Cancer Patients Treated With Neoadjuvant Chemoradiotherapy

OBJECTIVE

The systemic inflammatory response (SIR) is known as an important factor associated with tumorigenesis and tumor progression, and can be reflected by inflammatory markers. One of the markers that reflect this is the lung immune prognostic index (LIPI). It is based on a derived neutrophil-to-lymphocyte ratio (dNLR) and lactate dehydrogenase (LDH) level. We aimed to investigate the significance of LIPI in locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (NACRT).

METHODS

In this retrospective study, we stratified the patients according to LIPI score as good LIPI and intermediate (int)/poor LIPI. According to pathological response to NACRT, we divided the patients into two groups as those with complete response (CR) or near-CR, and those with partial response (PR) or poor/no response. We classified CR and near-CR as good response. We evaluated the predictive and prognostic significance of LIPI for NACRT response, disease-free survival (DFS), and overall survival (OS) by univariate and multivariate analyses.

RESULTS

We included 137 patients in the results, with 72 (52.6%) having good LIPI and 65 (47.4%) having int/poor LIPI. The median follow-up period was 44.7 months (range: 10-105 months). Thirteen patients (18.0%) in the good LIPI group and 22 patients (34.0%) in the int/poor LIPI group achieved good response. In multivariate analysis, we found only the LIPI score as an independent risk factor (hazard ratio (HR): 2.4, p = 0.04) for NACRT response. Median DFS was 89.2 months (95% CI: 11.4-167.0) in the int/poor LIPI group; however, the DFS of all study populations and patients in the good LIPI group did not reach the median value. In multivariate analysis for DFS, we identified abdominoperineal resection (APR) (HR: 2.21, p = 0.02), presence of tumor deposit (HR: 2.96, p = 0.003), and int/poor LIPI score (HR: 2.07, p = 0.02) as separate risk variables. OS of all study populations and the patients in the LIPI groups did not reach the median value. In multivariate analysis for OS, we identified APR (HR: 2.74, p = 0.02), surgical margin positivity (HR: 12.94, p < 0.001), and adjuvant CT (HR: 0.20, p = 0.002) as separate risk variables for OS.

CONCLUSION

This is the first study investigating the predictive and prognostic significance of LIPI in LARC patients treated with NACRT. The results revealed that int/poor LIPI was associated with a higher rate of good response but shorter DFS compared to good LIPI. The baseline LIPI score serves as an easily accessible and useful prognostic index, and it has significant potential for making appropriate treatment decisions in LARC.

Efficacy of concurrent radiotherapy in patients with locally advanced rectal cancer and synchronous metastasis receiving systemic therapy

Background

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is the standard treatment for patients with nonmetastatic locally advanced rectal cancer (LARC). However, for patients with LARC and synchronous metastasis, the optimal treatment strategy and sequence remain inconclusive. In the present study, we evaluated the efficacy and safety of concurrent radiotherapy in patients with de novo metastatic rectal cancer who received chemotherapy and targeted therapy.

Methods

We retrospectively reviewed the data of 63 patients with LARC and synchronous metastasis who received intensive therapy at the study hospital between April 2015 and November 2018. The included patients were divided into two groups: RT-CT, those who received systemic chemotherapy with targeted therapy and concurrent radiotherapy (for primary rectal cancer), and CT, those who received only systemic chemotherapy with targeted therapy.

Results

Treatment response was better in the RT-CT group than in the CT group. The rate of primary tumor resection (PTR) was higher in the RT-CT group than in the CT group (71.4% and 42.9%, respectively; P = .0286). The RT-CT group exhibited considerably longer local recurrence-free survival (P = .0453) and progression-free survival (PFS; from 13.3 to 22.5 months) than did the CT group (P = .0091); however, the groups did not differ in terms of overall survival (OS; P = .49). Adverse events were almost similar between the groups, except frequent diarrhea, the prevalence of which was higher in the RT-CT group than in the CT group (59.5% and 23.8%, respectively; P = .0075).

Conclusions

In the era of biologics, radiotherapy may increase the resectability of primary rectal tumors, reducing the risk of locoregional failure and prolonging PFS. Concurrent pelvic radiotherapy may not substantially improve OS, which is indicated by metastasis. Hence, the resection of the distant metastases may be essential for improving long-term OS. To further determine the efficacy of concurrent radiotherapy, additional prospective, randomized studies must combine preoperative pelvic radiotherapy with PTR and metastectomy to treat patients with stage IV LARC.

Clinical Implication of Perineural and Lymphovascular Invasion in Rectal Cancer Patients Who Underwent Surgery After Preoperative Chemoradiotherapy

BACKGROUND

Lymphovascular and perineural invasion are well-known negative prognostic indicators in rectal cancer, but previous studies on their significance are not consistent.

OBJECTIVE

This study assessed the prognostic value of lymphovascular and perineural invasion in rectal cancer patients who received preoperative chemoradiotherapy followed by curative resection.

DESIGN

This is a retrospective analysis.

SETTING

This study was performed at a tertiary cancer center.

PATIENTS

Rectal cancer patients who underwent curative resection after preoperative chemoradiotherapy between January 2000 and December 2010.

MAIN OUTCOME MEASURES

The primary outcomes were disease-free survival and overall survival. The survival rates were estimated using Kaplan-Meier analysis, and group comparisons were conducted using a log-rank test.

RESULTS

Of the 1156 included patients, 109 (9.4%) presented with lymphovascular invasion and 137 (11.9%) presented with perineural invasion. Lymphovascular and perineural invasion were associated with T and N downstaging after preoperative chemoradiotherapy ( p < 0.001). In the ypN0 patients, the 5-year disease-free survival rates were 70.8% and 78.5% ( p = 0.150) for the lymphovascular invasion and absent groups, respectively. In the perineural invasion group, the 5-year disease-free survival rate was 59.0% compared to 80.2% in the absent group ( p = 0.001). Among the ypN+ patients, the 5-year disease-free survival rates were 36.9% and 44.4% for the lymphovascular invasion and absent groups, respectively ( p = 0.211). The perineural invasion group had a poorer 5-year disease-free survival rate compared to the absent group (29.7% vs 46.7%; p = 0.011). By multivariable analyses, perineural invasion correlated with a poor disease-free survival (HR 1.412, 95% CI 1.082-1.843; p = 0.011) and also in ypN0 subgroup analysis (HR 1.717, 95% CI 1.093-2.697; p = 0.019).

LIMITATIONS

This study was a retrospective study conducted at a single center.

CONCLUSIONS

Perineural invasion is a reliable independent predictor of recurrence in rectal cancer patients treated with preoperative chemoradiotherapy. Patients with perineural invasion should be considered for closer surveillance even with ypN0 status. See Video Abstract at http://links.lww.com/DCR/B833 .IMPLICACIÓN CLÍNICA DE LA INVASIÓN PERINEURAL Y LINFOVASCULAR EN PACIENTES CON CÁNCER DE RECTO SOMETIDOS A CIRUGÍA DESPUÉS DE QUIMIORRADIOTERAPIA PREOPERATORIA.

ANTECEDENTES

La invasión linfovascular y perineural en cancer de recto, son indicadores pronósticos negativos bien conocidos, pero estudios previos sobre su significancia, no son consistentes.

OBJETIVO

El estudio evaluó el valor pronóstico de la invasión linfovascular y perineural en pacientes con cáncer de recto sometidos a quimiorradioterapia preoperatoria seguida de resección curativa.

DISEO

Es un análisis retrospectivo.

ENTORNO CLINICO

El estudio se realizó en un centro oncológico terciario.

PACIENTES

Pacientes con cáncer de recto sometidos a resección curativa después de quimiorradioterapia preoperatoria entre enero de 2000 y diciembre de 2010.

PRINCIPALES MEDIDAS DE VALORACION

Los resultados primarios fueron la supervivencia libre de enfermedad y la supervivencia general. Las tasas de supervivencia se estimaron mediante el análisis de Kaplan-Meier y las comparaciones de grupos se realizaron mediante una prueba de rango logarítmico.

RESULTADOS

De los 1156 pacientes incluidos, 109 (9,4%) presentaron invasión linfovascular y 137 (11,9%) invasión perineural. La invasión linfovascular y perineural se asoció con reducción del estadio de T y N después de la quimiorradioterapia preoperatoria ( p < 0,001). En los pacientes ypN0, las tasas de supervivencia libre de enfermedad a 5 años fueron del 70,8% y el 78,5% ( p = 0,150) para los grupos con y sin invasión linfovascular, respectivamente. En el grupo de invasión perineural, la tasa de supervivencia libre de enfermedad a 5 años fue del 59,0%, en comparación con el 80,2% en el grupo ausente ( p = 0,001). Entre los pacientes ypN +, las tasas de supervivencia sin enfermedad a 5 años fueron del 36,9% y 44,4% para los grupos con y sin invasión linfovascular, respectivamente ( p = 0,211). El grupo de invasión perineural mostró una tasa de supervivencia libre de enfermedad a 5 años menor, en comparación con el grupo ausente (29,7% versus 46,7%, p = 0,011). Mediante análisis multivariable, la invasión perineural se correlacionó con una pobre tasa de supervivencia de enfermedad (índice de riesgo 1,412; intervalo de confianza del 95%: 1,082-1,843; p = 0,011) y también en el análisis de subgrupos ypN0 (índice de riesgo 1,717; intervalo de confianza del 95%: 1,093-2,697; p = 0,019).

LIMITACIONES

Estudio retrospectivo realizado en un solo centro.

CONCLUSIONES

La invasión perineural es un predictor independiente y confiable de recurrencia en pacientes con cáncer de recto tratados con quimiorradioterapia preoperatoria. Los pacientes con invasión perineural deben considerarse para una vigilancia más estrecha incluso con estadio ypN0. Consulte Video Resumen en http://links.lww.com/DCR/B833 . (Traducción-Dr. Fidel Ruiz Healy ).

Sacroperineal Reconstruction With Inferior Gluteal Artery Perforator Flaps After Resection of Locally Advanced Primary and Recurrent Anorectal Malignancy

ABSTRACT

Modern interdisciplinary concepts with involvement of various surgical specialties can considerably reduce perioperative morbidity after sacroperineal resection of locally advanced primary or recurrent anorectal malignancies. Resultant defects can represent a major challenge for reconstruction particularly with chemoradiotherapy. The aim is to assess the long-term outcomes of sacroperineal reconstruction using inferior gluteal artery perforator flaps.We performed a retrospective data analysis on 31 patients who were treated with inferior gluteal artery perforator flaps (n = 61) over the period 2009-2021. The demographic data, comorbidities, operative details, and outcomes with special focus on wound infection and dehiscence were recorded.The median age was 42 year (range, 25-82 years) with preponderance of males (n = 21). The follow-up period ranged from 6 to 80 months. Early minor complications included superficial wound dehiscence (3), which was managed conservatively, whereas the major (2) included deep wound collection and infection (1), which required surgical drainage, and perineal hernia, which required repair. All flaps survived completely.Inferior gluteal artery perforator flaps are safe, robust, and reliable with less donor side morbidity and positive impact on quality of life. It should be considered as a valuable tool in the reconstructive armamentarium of sacroperineal defects within a multidisciplinary setting.

Is robotic da Vinci Xi® superior to the da Vinci Si® for sphincter-preserving total mesorectal excision? Outcomes in 150 mid-low rectal cancer patients

The aim of this study was to determine the superiority between the robotic da Vinci Si® (Si group) and da Vinci Xi® (Xi group) generation in patients with mid-low rectal cancer. Between December 2011 and December 2017, 88 patients with mid-low rectal cancer were operated on using the Si robotic system, from January 2018 to May 2021, 62 more patients with mid-low rectal cancer were operated on using the Xi robotic system. Perioperative and postoperative short-term outcomes were compared between the two groups. Univariate and multivariate Cox-regression analysis were performed to determine factors affecting operating time. A cumulative sum (CUSUM) analysis was also performed to determine the learning curve of the primary surgeon. All patients underwent sphincter saving total mesorectal excision (TME). The overall operating time was significantly shorter in the Xi group (181.3 ± 31.8 min in Si group vs 123.6 ± 25.7 min in the Xi group, p < 0.001). There were no significant differences in terms of conversion rates, mean hospital stays, complications and histopathologic data. CUSUM analysis show completion of learning curve in 44th case of Si group. Univariate and multivariate analysis demonstrated that the learning curve of the primary surgeon (p < 0.001) and the type of robotic system (Xi) are only two factors associated with operating time (OR, 95% CI p; 3.656, 0.665-9.339, p < 0.001). Our study found that the robotic da Vinci Xi systems provide significantly shorter operating time comparing with Si systems, when performing sphincter-preserving TME in mid-low rectal cancer patients. Surgical system (da Vinci Xi) and primary surgeon learning curve are two independent risk factors which associated shortened operating time. Postoperative complication rates and histopathologic outcomes are similar in both groups.

Robotic versus laparoscopic surgery for rectal cancer after neoadjuvant chemoradiotherapy: A propensity-score matching analysis

BACKGROUND

We aimed to investigate the advantages of robotic versus laparoscopic surgery for rectal cancer after neoadjuvant chemoradiotherapy as these remains unclear.

METHODS

We retrospectively recruited eligible patients with rectal cancer undergoing robotic or laparoscopic surgery following neoadjuvant chemoradiotherapy. We compared the surgical outcomes between patients undergoing either robotic surgery or laparoscopic surgery was based on the propensity-score matching analysis.

RESULTS

A total of 171 patients were recruited, including 76 who underwent robotic surgery and 95 who underwent laparoscopic surgery. There were no significant differences in clinical and pathological characteristics between the groups after propensity-score matching (56 matched pairs). Longer operation times (324.964 ± 83.435 vs. 246.232 ± 111.324 min, p < 0.001) and more blood loss (187.679 ± 176.615 vs. 98.214 ± 107.011, p < 0.001) were observed in the robotic group. The major complication rates were similar between the treatment groups after propensity matching (p = 0.086). There were no significant differences in disease-free survival rates (p = 0.205) and overall survival rates (p = 0.837) between the groups.

CONCLUSIONS

Robotic surgery is associated with similar technical safety and oncologic efficacy compared to laparoscopic surgery for the treatment of rectal cancer after neoadjuvant chemoradiotherapy; it is an acceptable option for patients requiring minimally invasive surgery. Nevertheless, the longer operation times and greater blood loss seen in the present study are a stark reminder that the convenience and surgical precision, on which the marketing of robotic surgery is rooted, are yet to be proven and require further investigation.

Treatment in locally advanced rectal cancer: a machine learning bibliometric analysis

A bibliometric analysis was performed using a machine learning bibliometric methodology in order to evaluate the research trends in locally advanced rectal cancer treatment between 2000 and 2020. Information regarding publication outputs, countries, institutions, journals, keywords, funding, and citation counts was retrieved from Scopus database. During the search process, a total of 2370 publications were identified. The vast majority of papers originated from the United States of America, reflecting also its research drive in the collaboration network. Neoadjuvant treatment was the topic most studied in the highly cited studies. New keywords, including neoadjuvant chemotherapy, multiparametric magnetic resonance imaging, circulating tumor DNA, and genetic heterogeneity, appeared in the last 2 years. The quantity of publications on locally advanced rectal cancer treatment since 2000 showed an evolving research field. The 'new' keywords explain where research is presently heading.

Anus-Preserving Surgery in Advanced Low-Lying Rectal Cancer: A Perspective on Oncological Safety of Intersphincteric Resection

The surgical management of low-lying rectal cancer, within 5 cm from the anal verge (AV), is challenging due to the possibility, or not, to preserve the anus with its sphincter muscles maintaining oncological safety. The standardization of total mesorectal excision, the adoption of neoadjuvant chemoradiotherapy, the implementation of rectal magnetic resonance imaging, and the evolution of mechanical staplers have increased the rate of anus-preserving surgeries. Moreover, extensive anatomy and physiology studies have increased the understanding of the complexity of the deep pelvis. Intersphincteric resection (ISR) was introduced nearly three decades ago as the ultimate anus-preserving surgery. The definition and indication of ISR have changed over time. The adoption of the robotic platform provides excellent perioperative results with no differences in oncological outcomes. Pushing the boundaries of anus-preserving surgeries has risen doubts on oncological safety in order to preserve function. This review critically discusses the oncological safety of ISR by evaluating the anatomical characteristics of the deep pelvis, the clinical indications, the role of distal and circumferential resection margins, the role of the neoadjuvant chemoradiotherapy, the outcomes between surgical approaches (open, laparoscopic, and robotic), the comparison with abdominoperineal resection, the risk factors for oncological outcomes and local recurrence, the patterns of local recurrences after ISR, considerations on functional outcomes after ISR, and learning curve and surgical education on ISR.

Clinical outcome of neoadjuvant chemoradiation in rectal cancer treatment

To determine the clinical and pathological outcome of locally advanced rectal cancer patients treated with neoadjuvant chemoradiation (chemoradiotherapy [CRT]) followed by curative surgery and to identify predictive factors of pathological complete response (pCR).Locally advanced rectal cancer patients undergoing CRT followed by curative surgery from January 2012 to December 2017 were included. Patient's demographic data, pretreatment tumor characteristics, type of CRT regimens, type of surgery, postoperative complications, pathological reports and follow up records were analyzed. Univariate and multivariate analyses were applied to identify predictive factors for pCR. Five-year disease free and overall survival were estimated by Kaplan-Meier method and compared between pCR and non-pCR groups.A total of 85 patients were analyzed. Eighteen patients (21.1%) achieved pCR. The sphincter-saving surgery rate was 57.6%. After univariate analyses, tumor length >4 cm (P = .007) and positive lymph nodes (P = .040) were significantly associated with decreased rate of pCR. Complete clinical response was significantly associated with higher rate of pCR (P = .015). Multivariate analyses demonstrated that tumor length >4 cm (P = .010) was significantly associated with decreased rate of pCR. After a median follow-up of 65 months (IQR 34-79), the calculated 5-year overall survival and disease-free survival rates were 81.4% and 69.7%, respectively. Patients who achieved pCR tend to had longer 5-year disease-free survival (P = .355) and overall survival (P = .361) than those who did not.Tumor length >4 cm was associated with decreased rate of pCR in locally advanced rectal cancer who had CRT followed by surgery. Longer waiting time or more intense adjuvant treatment may be considered to improved pCR and oncological outcomes.

Circulating Hybrid Cells: A Novel Liquid Biomarker of Treatment Response in Gastrointestinal Cancers

BACKGROUND

Real-time monitoring of treatment response with a liquid biomarker has potential to inform treatment decisions for patients with rectal adenocarcinoma (RAC), esophageal adenocarcinoma (EAC), and colorectal liver metastasis (CRLM). Circulating hybrid cells (CHCs), which have both immune and tumor cell phenotypes, are detectable in the peripheral blood of patients with gastrointestinal cancers, but their potential as an indicator of treatment response is unexplored.

METHODS

Peripheral blood specimens were collected from RAC and EAC patients after neoadjuvant therapy (NAT) or longitudinally during therapy and evaluated for CHC levels by immunostaining. Receiver operating characteristics (ROCs) and the Kaplan-Meier method were used to analyze the CHC level as a predictor of pathologic response to NAT and disease-specific survival (DSS), respectively.

RESULTS

Patients with RAC (n = 23) and EAC (n = 34) were sampled on the day of resection, and 11 patients (32%) demonstrated a pathologic complete response (pCR) to NAT. On ROC analysis, CHC levels successfully discriminated pCR from non-pCR with an area under the curve of 0.82 (95% confidence interval [CI], 0.71-0.92; P < 0.001). Additionally, CHC levels in the EAC patients correlated with residual nodal involvement (P = 0.026) and 1-year DSS (P = 0.029). The patients with RAC who were followed longitudinally during NAT (n = 2) and hepatic arterial infusion therapy for CRLM (n = 2) had CHC levels that decreased with therapy response and increased before clinical evidence of disease progression.

CONCLUSION

Circulating hybrid cells are a novel blood-based biomarker with potential for monitoring treatment response and disease progression to help guide decisions for further systemic therapy, definitive resection, and post-therapy surveillance. Additional validation studies of CHCs are warranted.

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

High-Risk Clinicopathological and Genetic Features and Outcomes in Patients Receiving Neoadjuvant Radiochemotherapy for Locally Advanced Rectal Cancer

Simple Summary

The overall genomic copy number changes profile of three subgroups of locally advanced rectal carcinoma patients with significantly different response to neoadjuvant treatment with radiochemotherapy (ranging from complete to poor- or no-response) was analyzed and compared with a set of normal samples from healthy individuals with negative colonoscopies from the Castilla y León (Spain) region. We identified and validated a novel genetic signature, which combined with clinicopathological features, predicts response to neoadjuvant treatment and clinical outcome.

Abstract

Administering preoperative radiochemotherapy (RCT) in stage II-III tumors to locally advanced rectal carcinoma patients has proved to be effective in a high percentage of cases. Despite this, 20–30% of patients show no response or even disease progression. At present, preoperative response is assessed by a combination of imaging and tumor regression on histopathology, but recent studies suggest that various genetic abnormalities may be associated with the sensitivity or resistance of rectal cancer tumor cells to neoadjuvant therapy. In the present study we investigated the relationship between genetic lesions detected by high-density single-nucleotide polymorphisms (SNP) arrays 6.0 and response to neoadjuvant RCT, evaluated according to Dworak criteria in 39 rectal cancer tumors before treatment. The highest frequency of copy-number (CN) losses detected corresponded to chromosomes 18q (n = 27; 69%), 1p (n = 22; 56%), 15q (n = 19; 49%), 8p (n = 18; 48%), 4q (n = 17; 46%), and 22q (n = 17; 46%); in turn, CN gains more frequently involved chromosomes 20p (n = 22; 56%), 8p (n = 20; 51%), and 15q (n = 16; 41%). There was a significant association between alterations in the 1p, 3q, 7q, 12p, 17q, 20p, and 22q chromosomal regions and the degree of response to therapy prior to surgery. However, 4q, 15q11.1, and 15q14 chromosomal region alterations were identified as important by five prediction algorithms, i.e., those with the greatest influence on predicting the tumor response to treatment with preoperative RCT. Multivariate analysis of prognostic factors showed that gains on 15q11.1 and carcinoembryonic antigen (CEA) levels serum at diagnosis were the only independent variables predicting disease-free survival (DFS). Lymph node involvement also showed a prognostic impact on overall survival (OS) in the multivariate analysis. A deep-learning-based algorithm showed a 100% success rate in predicting both DFS and OS at 60 months after diagnosis of the disease. In summary, our results indicate the existence of an association between tumor genetic abnormalities at diagnosis, response to neoadjuvant therapy, and survival of patients with locally advanced rectal cancer. In addition to the clinical and biological characteristics of locally advanced rectal cancer patients, these could be used in the future as therapeutic and prognostic biomarkers, to identify patients sensitive or resistant to preoperative treatment, helping guide therapeutic decision-making. Additional prospective studies in larger series of patients are required to confirm the clinical utility of the newly identified biomarkers.

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

BACKGROUND/AIM

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Effect of mistletoe extract on tumor response in neoadjuvant chemoradiotherapy for rectal cancer: a cohort study

Background

Mistletoe extract, used as a complementary chemotherapeutic agent for cancer patients, has anticancer effects against various malignancies. The aim of the present study was to evaluate the effect of mistletoe extract (Abnoba Viscum Q®) on tumor responses to neoadjuvant chemoradiotherapy (NCRT) for locally advanced rectal cancer.

Methods

This study included patients with rectal cancer who underwent NCRT between January 2018 and July 2020. In the mistletoe group (MG), the patients were administered Abnoba Viscum Q® subcutaneously during chemoradiotherapy—maintained just before surgery. Patient demographics, clinical outcomes, histopathological outcomes, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay results were compared between the MG and non-mistletoe group (NMG). Two rectal cancer cell lines (SNU-503 and SNU-503R80Gy) were treated with Abnoba Viscum Q® to assess its mechanistic effects in vivo.

Results

Overall, the study included 52 patients (MG: n = 15; NMG: n = 37). Baseline demographics between the two groups were similar, except carbohydrate antigen 19-9 levels and tumor location from the anal verge. There was no difference in the clinical stage between the two groups. A better tumor response in the MG, relative to the NMG, was observed with respect to tumor regression grade (TRG), T stage, and overall tumor–node–metastasis stage. Tumor response was significantly better in the MG than in the NMG in terms of pathologic complete response rate (53.3% vs. 21.6%, P = 0.044), good TRG response (66.7% vs. 32.4%, P = 0.024), T downstaging (86.7% vs. 43.2%, P = 0.004), and overall downstaging (86.7% vs. 56.8%, P = 0.040). The toxicities during NCRT were minimal in both groups. More apoptotic cells were noted in MG samples than in the NMG samples on TUNEL staining. Cleaved caspase-3 level following treatment with Abnoba Viscum Q® was higher in SNU-503R80Gy cells than in SNU-503 cells.

Conclusion

Patients treated with chemoradiation combined with mistletoe extract showed better outcomes than patients not treated with mistletoe extract in terms of tumor responses. This diversity in treatment may improve the efficacy of NCRT, leading to better oncologic outcomes. Prospective and randomized studies with long-term follow-up are warranted to confirm and extend these results.

Association Between Pathological Complete Response and Tumor Location in Patients with Rectal Cancer After Neoadjuvant Chemoradiotherapy, a Prospective Cohort Study

Background: Colorectal cancers are the third common malignancies after lung and breast neoplasms. Some contributing factors for pathological complete response (pCR) to neoadjuvant therapy of rectal cancer have been defined. Despite various studies in this era, there are few studies on the location of tumors. Objectives: Regarding the high prevalence of colorectal cancer in Iran and the importance of neoadjuvant chemoradiation for survival and morbidity, this study was carried out to determine the association between pathologic complete response and tumor location in patients with rectal cancer after neoadjuvant chemoradiotherapy. Methods: In this prospective cohort, 100 cases with rectal adenocarcinoma from 2017 to 2019 were enrolled. Distance between anal verge and tumor was measured by clinical examination, colonoscopy, endo-sonography, and MRI. Tumors were defined as distal (less than 5 cm from the anal verge) and none distal (more than 5 cm from the anal verge). Another subdivision was inferior (0 - 4.99 cm), middle (5 - 9.99 cm), and superior (10 - 15 cm). The pathological response was compared across the groups. Results: In this study, the pCR was seen in 30%. In univariate analysis body mass index (BMI), grade, N-stage, and distance from anal verge were related to pCR. In cases with BMI over 25 kg/m2 and in tumors with low to medium grade N0/N1, and distance less than 5 cm from the anal verge (low lying tumors) the pCR to neoadjuvant treatment was higher. In multivariate analysis tumor grade, N stage, and distance from anal verge were still related to pCR. Conclusions: According to the obtained results in this study, there may be some association between rectal tumor location and pathologic complete response.

Evolution and Current Status of the Multidisciplinary Management of Locally Advanced Rectal Cancer

The management of locally advanced rectal cancer has grown in both complexity and quality since the first proctectomy. What once was a malignancy with a fairly consistent treatment algorithm for decades, a recent paradigm shift in the care of these patients has led to a more personalized, multidisciplinary approach with variations in timing, sequence, duration, and potential exclusion of multimodality therapies. This review summarizes the most important evidence behind these developing overarching concepts to provide a context for this paradigm shift.

Outcomes of neoadjuvant chemoradiotherapy followed by radical resection for T4 colorectal cancer

BACKGROUND

Patients with clinical T4 colorectal cancer (CRC) have a poor prognosis because of compromised surgical margins. Neoadjuvant therapy may be effective in downstaging tumors, thereby rendering possible radical resection with clear margins.

AIM

To evaluate tumor downsizing and resection with clear margins in T4 CRC patients undergoing neoadjuvant concurrent chemoradiotherapy followed by surgery.

METHODS

This study retrospectively included 86 eligible patients with clinical T4 CRC who underwent neoadjuvant concurrent chemoradiotherapy followed by radical resection. Neoadjuvant therapy consisted of radiation therapy at a dose of 45-50.4 Gy and chemotherapy agents, either FOLFOX or capecitabine. A circumferential resection margin (CRM) of < 1 mm was considered to be a positive margin. We defined pathological complete response (pCR) as the absence of any malignant cells in a specimen, including the primary tumor and lymph nodes. A multivariate logistic regression model was used to identify independent predictive factors for pCR.

RESULTS

For 86 patients who underwent neoadjuvant chemoradiotherapy and surgery, the rate of pCR was 14%, and the R0 resection rate was 91.9%. Of the 61 patients with rectal cancer, 7 (11.5%) achieved pCR and 5 (8.2%) had positive CRMs. Of the 25 patients with colon cancer, 5 (20%) achieved pCR and 2 (8%) had positive CRMs. We observed that the FOLFOX regimen was an independent predictor of pCR (P = 0.046). After a median follow-up of 47 mo, the estimated 5-year overall survival (OS) and disease-free survival (DFS) rates were 70.8% and 61.4%, respectively. Multivariate analysis revealed that a tumor with a negative resection margin was associated with improved DFS (P = 0.014) and OS (P = 0.001). Patients who achieved pCR exhibited longer DFS (P = 0.042) and OS (P = 0.003) than those who did not.

CONCLUSION

Neoadjuvant concurrent chemoradiotherapy engenders favorable pCR and R0 resection rates among patients with T4 CRC. The R0 resection rate and pCR are independent prognostic factors for patients with T4 CRC.

The impact of sarcopenia on pathologic complete response following neoadjuvant chemoradiation in rectal cancer

PURPOSE

The role of sarcopenia in pathologic complete response (pCR) following neoadjuvant chemoradiotherapy (nCRT) in non-metastatic locally advanced rectal cancer is currently unknown. The present study investigates the association between sarcopenia and post-nCRT pCR.

METHODS

The data of patients operated on following nCRT between January 2013 and January 2020 were collected retrospectively. Sarcopenia was diagnosed based on the calculation of the skeletal muscle index (SMI) from computed tomography carried out at the time of the initial diagnosis. A statistical analysis was then conducted for predictors of pCR.

RESULTS

The study included 61 patients with an average age of 57.3 years, 28 of whom formed the non-sarcopenic group (NSG) and 33 the sarcopenic group (SG). Of the patients, 32.7% were at clinical stage 2, and 67.3% were at clinical stage 3. Pathologic data following a mesorectal excision revealed a pCR rate of 21.4% in the NSG compared with 3% in the SG, which was a statistically significant difference (p = 0.025). The TNM downstaging rate was higher in the NSG than in the SG, although the difference was not statistically significant (50% vs. 33.3%, p = 0.28). A univariate analysis revealed the factors affecting pCR to be non-sarcopenia (p = 0.025), age < 61 years (p = 0.004), interval to surgery ≥ 8 weeks (p = 0.029), and serum CEA < 2.5 ng/ml (p = 0.035).

CONCLUSION

Sarcopenia was found to be a negative marker of pCR following nCRT in non-metastatic locally advanced rectal cancer.

Phase II Trial of Neoadjuvant Bevacizumab with Modified FOLFOX7 in Patients with Stage II and III Rectal Cancer

LESSONS LEARNED

Neoadjuvant bevacizumab with modified FOLFOX7 without radiation failed to meet the goal of pathological complete response rate; however, the low number of recurrence and disease-free survival in this population, with predominantly stage III, is encouraging and worth further exploration. The racial distribution of the patient population, as well as a wait time of more than 4 weeks after last chemotherapy, may have contributed to the findings.

BACKGROUND

Combination chemotherapy in lieu of radiation in rectal adenocarcinoma is under exploration in multiple trials. We evaluated the efficacy of neoadjuvant FOLFOX + bevacizumab in patients (pts) with clinical stage II and III disease.

METHODS

Pts received six cycles of bevacizumab (5 mg/kg) and modified FOLFOX7 (oxaliplatin 85 mg/m² , leucovorin 20 mg/m² , and fluorouracil [5-FU] 2,400 mg/m² ). Surgical resection was performed 6-8 weeks after completion of treatment and upon confirmation of nonmetastatic disease. We employed a Simon two-stage design and required three pathological complete responses (pCR) in the first 18 pts, with a prespecified pCR rate of 25% before moving to the next stage.

RESULTS

Seventeen pts enrolled; 65% at stage III. Median age was 57 (35-79), 65% were male, 47% were Hispanic, 35% were white, and 18% were Asian. All pts but one completed six cycles of therapy. One pCR was observed (6%), and 11 of 17 (65%) pts had pathological downstaging. One patient experienced systemic recurrence and remains on treatment. Probability of disease-free survival (DFS) at 5 years is 0.94 (SE, 0.06).

CONCLUSION

The study failed to meet the required three pCRs in the first 18 pts. The DFS in this population is encouraging and supports the hypothesis that select pts with rectal cancer may be spared from radiation.

The impact of tumor regression grade on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PURPOSE

The aim of this study is to investigate the prognostic effect of tumor regression grade (TRG) on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy.

METHODS

Medical records of 182 patients with locally advanced rectal cancer, who were treated with preoperative chemoradiotherapy followed by surgery between 2002 and 2016, were retrospectively reviewed. TRG was classified into five categories based on the pathological response as follows - TRG1: no viable cancer cell, TRG2: single cancer cell or small groups of cancer cells, TRG3: residual tumor outgrown by fibrosis, TRG4: residual tumor outgrowing fibrosis, TRG5: diffuse residual tumor without regression. TRG1, (TRG2+TRG3), and (TRG4+TRG5) were grouped as complete response, intermediate response, and no response, respectively.

RESULTS

Of the 182 patients with locally advanced rectal cancer, 112 (61.5%) were male. The mean age was 54.4 (range, 25-87) years. The total number of patients in complete response, intermediate response, and no response group was 24 (13.2%), 105 (57.7%), and 53 (29.1%), respectively. The corresponding five-year relapse-free survival and overall survival rates were 79.8%-92.3%, 74.7%-79.4%, and 55.7%-55.8%, respectively (p < 0.05 for relapse-free survival, p < 0.05 for overall survival). According to ypTNM stage, there was no significant difference in relapse-free survival among TRG groups in ypStage I and II patients (p > 0.05). In ypStage III patients, relapse-free survival was 62 months in no response group vs. not reached in intermediate response group (p < 0.05). According to the ypTNM, there was no significant difference in overall survival among TRG groups in ypStage I, II, and III patients (p > 0.05). In the multivariate analysis, pathological complete response was found to be an independent variable for relapse-free survival and overall survival (hazard ratio (95% confidence interval), 0.34 (0.17-6.77), 0.39 (0.18-0.83), respectively).

CONCLUSION

This study showed that patients with pathological complete response to preoperative chemoradiotherapy had longer relapse-free survival and overall survival rates than those with residual disease.

Predictive immunohistochemical features for tumour response to chemoradiotherapy in rectal cancer

Background

Reduced expression of cluster of differentiation (CD) 133 and cyclo‐oxygenase (COX) 2, and increased density of CD8+ tumour‐infiltrating lymphocytes, are associated with a favourable tumour response to preoperative chemoradiotherapy (CRT). This study aimed to evaluate these markers in relation to tumour response after preoperative CRT in two rectal cancer cohorts.

Methods

Patients with low rectal cancer who underwent radical resection and preoperative short‐term CRT in 2001–2007 (retrospective cohort) and long‐term CRT in 2011–2017 (prospective cohort) were analysed. Pretreatment biopsies were stained immunohistochemically using antibodies to determine CD133 and COX‐2 expression, and increased CD8+ density. Outcome measures were tumour regression grade (TRG), tumour downstaging and survival.

Results

For 95 patients in the retrospective cohort, the incidence of TRG 3–4 was 67 per cent when two or three immunohistochemistry (IHC) features were present, but only 20 per cent when there were fewer features (P < 0·001). The incidence of tumour downstaging was higher in patients with at least two IHC features (43 versus 22 per cent with fewer features; P = 0·029). The 49 patients in the prospective cohort had similar rates to those in the retrospective cohort (TRG 3–4: 76 per cent for two or more IHC features versus 25 per cent with fewer features, P < 0·001; tumour downstaging: 57 versus 25 per cent respectively, P = 0·022). Local recurrence‐free survival rates in patients with more or fewer IHC features were similar in the retrospective and prospective cohort (P = 0·058 and P = 0·387 respectively).

Conclusion

Assessment of CD133, COX‐2 and CD8 could be useful in predicting a good response to preoperative CRT in patients with lower rectal cancer undergoing neoadjuvant therapy. Further studies are needed to validate the results in larger cohorts and investigate a survival benefit.

Proton beam radiotherapy for anal and rectal cancers

Gastrointestinal cancers are bordered by radiosensitive visceral organs, resulting in a narrow therapeutic window. The search for more efficacious and tolerable therapies raises the possibility that proton beam therapy's (PBT) physical and dosimetric differences from conventional therapy may be better suited to treat both primary and recurrent disease, which carries its own unique challenges. Currently, the maximal efficacy of radiation plans for primary and recurrent anorectal cancer is constrained by delivery techniques and modalities which must consider feasibility challenges and toxicity secondary to exposure of organs at risk (OARs). Studies using volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) demonstrate that more precise dose delivery to target volumes improves local control rates and reduces complications. By reducing the low-to-moderate radiation dose-bath to bone marrow, small and large bowel, and skin, PBT may offer an improved side-effect profile. The potential to reduce toxicity, increase patient compliance, minimize treatment breaks, and enable dose escalation or hypofractionation is appealing. In cases where prognosis is favorable, PBT may mitigate long-term morbidity such as secondary malignancies, femoral fractures, and small bowel obstruction.

The long-term oncological outcomes of the 140 robotic sphincter-saving total mesorectal excision for rectal cancer: a single surgeon experience

Robotic surgery became more popularly in the colorectal surgical field. The aim of the study was to evaluate of the oncological outcomes which patients who underwent the robotic total mesorectal excision for rectal cancer. A series of 140 consecutive patients who underwent robotic rectal surgery between January 2012 and June 2019 was analyzed retrospectively in terms of demographics, pathological data, and surgical and oncological outcomes. There were 104 (74.28%) male and 36 (25.71%) female patients. The tumor was located in the lower rectum in 84 (60%) cases, in the mid rectum in 38 (27.14%) cases, and in the upper rectum in 18 (12.85%) cases. Ninety-eight (70%) of the patients has received neoadjuvant chemoradiotherapy. All the patients underwent robotic sphincter-preserving surgery, 101 (72.14%) patients low-anterior resection, and 39 (27.85%) patients underwent intersphincteric resection with colo-anal anastomosis. There were no conversions. The circumferential resection margin was positive in five (3.57%) patients. The median distal resection margin of the operative specimen was 3.2 (0.2-7) cm. The median number of retrieved lymph nodes was 22 (16-42). TME quality in the in our study was rated as complete in 88.57% (n124) of patients, nearly complete in 7.14% (n10) of patients; and 4.28% (n6) of incomplete. The median hospital stay was 3.5 (3-12) days. In-hospital and 1-month mortality was zero. The median length of follow-up was 40 (2-80) months. The 5-year overall survival rate was 92.78%. The 5-year disease-free survival rate was 90%. Locally recurrence and distance recurrence rate was 3.57% (n5/140) and 2.85% (n4/140), respectively. Robotic rectal cancer surgery has a good oncological outcomes and feasible tool in the field of the rectal surgery, but required a steep learning curve.

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.

Prognostic Value of Clinical vs Pathologic Stage in Rectal Cancer Patients Receiving Neoadjuvant Therapy

Background

Neoadjuvant chemoradiation is currently standard of care in stage II-III rectal cancer, resulting in tumor downstaging for patients with treatment-responsive disease. However, the prognosis of the downstaged patient remains controversial. This work critically analyzes the relative contribution of pre- and post-therapy staging to the anticipated survival of downstaged patients.

Methods

The National Cancer Database (NCDB) was queried for patients with rectal cancer treated with transabdominal resection between 2004 and 2014. Stage II-III patients downstaged with neoadjuvant radiation were compared with stage I patients treated with definitive resection alone. Patients with positive surgical margins were excluded. Overall survival was evaluated using both Kaplan-Meier analyses and Cox proportional hazards models. All statistical tests were two-sided.

Results

A total of 44 320 patients were eligible for analysis. Survival was equivalent for patients presenting with cT1N0 disease undergoing resection (mean survival = 113.0 months, 95% confidence interval [CI] = 110.8 to 115.3 months) compared with those downstaged to pT1N0 from both cT3N0 (mean survival = 114.9 months, 95% CI = 110.4 to 119.3 months, P = .12) and cT3N1 disease (mean survival = 115.4 months, 95% CI = 110.1 to 120.7 months, P = .22). Survival statistically significantly improved in patients downstaged to pT2N0 from cT3N0 disease (mean survival = 109.0 months, 95% CI = 106.7 to 111.2 months, P < .001) and cT3N1 (mean survival = 112.8 months, 95% CI = 110.0 to 115.7 months, P < .001), compared with cT2N0 patients undergoing resection alone (mean survival = 100.0 months, 95% CI = 97.5 to 102.5 months). Multiple survival analysis confirmed that final pathologic stage dictated long-term outcomes in patients undergoing neoadjuvant radiation (hazard ratio [HR] of pT2 = 1.24, 95% CI = 1.10 to 1.41; HR of pT3 = 1.81, 95% CI = 1.61 to 2.05; HR of pT4 = 2.72, 95% CI = 2.28 to 3.25, all P ≤ .001 vs pT1; HR of pN1 = 1.50, 95% CI = 1.41 to 1.59; HR of pN2 = 2.17, 95% CI = 2.00 to 2.35, both P < .001 vs pN0); while clinical stage at presentation had little to no predictive value (HR of cT2 = 0.81, 95% CI = 0.69 to 0.95, P = .008; HR of cT3 = 0.83, 95% CI = 0.72 to 0.96, P = .009; HR of cT4 = 1.02, 95% CI = 0.85 to 1.21, P = .87 vs cT1; HR of cN1 = 0.96, 95% CI = 0.91 to 1.02, P = .19; HR of cN2 = 0.96, 95% CI = 0.86 to 1.08, P = .48 vs cN0).

Conclusions

Survival in patients with rectal cancer undergoing neoadjuvant radiation is driven by post-therapy pathologic stage, regardless of pretherapy clinical stage. These data will further inform prognostic discussions with patients.

Additional Chemotherapy with 5-FU plus Leucovorin between Preoperative Chemoradiotherapy and Surgery Improved Treatment Outcomes in Patients with Advanced Rectal Cancer

Purpose: The aim of the preliminary study was to evaluate the efficacy and safety of 4-week chemotherapy with 5-Fluorouracil and leucovorin (LV5FU2) during the resting periods between preoperative CRT and surgery in patients with LARC. Materials and Methods: Standard preoperative CRT was delivered to the entire pelvis at a total dose of 5040 Gy of radiation with concurrent 5-FU or capecitabine for 6 weeks. Twenty-three patients received additional preoperative chemotherapy with two cycles of 5-FU and LV (LV 200 mg/m2 and 5-FU bolus 400 mg/m2 on day 1, and 5-FU infusion 2400 mg/m2 for 46 hrs, every 2 weeks) after preoperative CRT. Surgery was performed at 2-4 weeks following the completion of preoperative chemotherapy. Results: Between May 2013 and January 2015, 23 patients underwent preoperative CRT, with additional chemotherapy and surgery, and 23 patients completed the scheduled treatment. The median follow-up duration was 42.0 months. The tumor down-staging rate was observed in 65.2%, and pathologic complete remission (pCR) was noted in 5 patients (21.7%). T and N down-staging were observed in 16 (69.6%) and 14 (60.9%) patients, respectively. The four-year disease-free survival (DFS) rate was 73.9% and the four-year overall survival (OS) rate was 90.9% in patients who received additional chemotherapy. The four-year DFS rate was 100% in the tumor down-staging group vs. 25.0% in the non-down staging group treated with additional chemotherapy (P <0.001). There was also a significant difference of the four-year OS rate 100% in the tumor down-staging group compared with 71.4% in the non-down staging group (P = 0.031). Conclusions: This preliminary study showed that additional preoperative chemotherapy with LV5FU2 was well tolerable and had an improvement in the downstaging rate and survival. Randomized controlled trial of this strategy is encouraged for definitive conclusions.

Predictors of surgical outcomes and survival in rectal cancer patients undergoing laparoscopic total mesorectal excision after neoadjuvant chemoradiation therapy: the interest of pelvimetry and restaging magnetic resonance imaging studies

BACKGROUND

Locally advanced rectal cancer (LARC) requires a multimodal therapy tailored to the patient and tumor characteristics. Pretreatment magnetic resonance imaging (MRI) is necessary to stage the primary tumor, while restaging MRI, which is not systematically performed, may be of interest to identify poor responders to neoadjuvant chemoradiation therapy (NCRT), and redefine therapeutic approach. The EuMaRCS study group aimed to investigate the role and accuracy of pretreatment (including pelvimetry) and restaging MRIs in predicting surgical difficulties and surgical outcomes in LARC therapy.

METHODS

Patients with mid or low LARC who were administered NCRT, who underwent laparoscopic total mesorectal excision, and for whom pretreatment and restaging MRIs were available, were included.

RESULTS

MRIs of 170 patients (median age: 61 years) were reanalyzed by the same radiologist. Pelvimetry differed significantly between males and females, but no gender difference was noted in the clinical and tumor characteristics. Tumor volume and tumor height assessed on the restaging MRI were associated, respectively, with operative time and estimated blood loss. Conversion was predicted by tumor volume, interischial distance and pubic tubercle height. The quality of the surgical resection was found to be a predictor of overall and disease-free survival. The sensitivity and specificity of tumor regression grade 1 to identify a pathologic complete response were 76.9% and 89.3%, respectively.

CONCLUSIONS

In LARC management, pelvimetry and restaging MRI may be useful to predict surgical difficulties and surgical outcomes. However, the main independent predictor of patient survival appears to be the achievement of a successful surgical resection.

MR Imaging with Apparent Diffusion Coefficient Histogram Analysis: Evaluation of Locally Advanced Rectal Cancer after Chemotherapy and Radiation Therapy

Purpose To determine response to neoadjuvant chemotherapy and radiation therapy in patients with locally advanced rectal cancer (LARC) by using magnetic resonance (MR) apparent diffusion coefficient (ADC) histogram analysis. Materials and Methods Ninety-two patients with LARC underwent MR imaging with rectal barium before and after chemotherapy and radiation therapy (CRT). Rectal expansion with barium expanded the lumen, provided similar imaging geometry before and after CRT, and eliminated fecal matter, air, and residual fluid. T2-weighted images, the percentage change in ADC, and ADC histogram skewness and kurtosis were assessed. The histopathologic tumor regression grade (TRG) ranged from 1a (66%-99% residual tumor cells) to 3 (no residual cells). The Wilcoxon signed-rank test, the Spearman correlation test, multivariable linear regression, and one-way analysis of variance were used to determine post- and pretreatment differences and correlations between tumor size and ADC. Results Of the 92 patients, 16 (17.4%) had TRG 3, 27 (29.3%) had TRG 2b, 24 (26.1%) had TRG 2a, 14 (15.2%) had TRG 1b, and 11 (12%) had TRG 1a. Post-CRT skewness (regression coefficient = 10.9, P = .06) and percentage ADC change (regression coefficient = -0.18, P = .03) were associated with the percentage of residual tumor. Post-CRT skewness and percentage ADC change, respectively, showed negative and positive correlation with histopathologic TRG (post-CRT skewness: P = .024; percentage ADC change: P = .001). Conclusion In patients with LARC, post-CRT skewness of the ADC histogram and percentage change in ADC were useful for predicting a favorable response to neoadjuvant CRT. ^© RSNA, 2018 Online supplemental material is available for this article.

Importance of the Circumferential Extent of Tumors and Clinical Lymph Node Status as Prognostic Factors after Preoperative Chemoradiotherapy and Surgery in Patients with Rectal Cancer

Aims and background

To evaluate the clinical factors that influence pathological and clinical outcomes after preoperative concurrent chemoradiotherapy in patients with rectal cancer.

Methods

Between 1999 and 2004, 121 patients with cT3-4 or node-positive rectal cancer received preoperative chemoradiotherapy and surgery. Preoperative radiation therapy with 45 Gy was delivered. Fluorouracil-based chemotherapy was administered to most of the patients.

Results

Pathological complete remission was 14.3% after preoperative chemoradiotherapy. More than 60% tumor circumferential extent was an independent adverse factor for complete remission (P = 0.011, HR 4.643, 95% CI 1.415–15.231). Local recurrence developed in 9.9% of the cases. Serum CEA level ≥5 ng/ml (P = 0.057, HR 3.022, 95% CI 0.967–9.441) and >60% circumferential extent of tumor (P = 0.064, HR 4.232, 95% CI 0.918–19.531) were marginal adverse factors for local recurrence. Five-year disease-free survival and overall survival were 72.2% and 86.6%, respectively. Disease-free survival was poor for patients with the lymph nodes ≥1 cm in diameter (P = 0.028), cN2 stage disease (P = 0.047) and >60% circumferential extent of tumor (P = 0.058). Multivariate analysis for disease-free survival showed that the lymph node size ≥1 cm was an adverse factor (P = 0.019, HR 2.380, 95% CI 1.115–4.906). Patients with >60% circumferential extent of tumor and cN2 stage had a more unfavorable survival than the other patients (disease-free survival, P = 0.018; overall survival, P = 0.015). Patients with >60% circumferential extent of tumor and/or lymph node ≥1 cm also had an unfavorable survival (disease-free survival, P = 0.016; overall survival, P = 0.049).

Conclusions

In rectal cancer, circumferential extent of tumor and clinical lymph node status were important factors for preoperative chemoradiotherapy and surgery. A further prospective study is needed to confirm and expand these findings.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypI stage after neoadjuvant chemo-radiotherapy versus de novo stage pI cohort: A propensity score-matched analysis

Objective

Prognosis of patients with locally advanced rectal cancer (LARC) but achieving ypT1-2N0 stage after neoadjuvant concurrent chemo-radiotherapy (CRT) has been shown to be favorable. This study aims to determine whether the long-term outcome of ypT1-2N0 cases can be comparable to that of pT1-2N0 cohort that received definitive surgery for early disease.

Method

From January 2008 to December 2013, 449 consecutive patients with rectal cancer were treated and their outcome maintained in a database. Patients with LARC underwent total mesorectal excision (TME) surgery at 4-8 weeks after completion of CRT, and those achieving stage ypI were identified as a group. As a comparison, stage pI group pertains to patients whose initially limited disease was not upstaged after TME surgery alone. After propensity score matching (PSM), comparisons of local regional control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) were performed using Kaplan-Meier analysis and log-rank test between ypI and pI groups. Down-staging depth score (DDS), a novel method of evaluating CRT response, was used for subset analysis.

Results

Of the 449 patients, 168 matched cases were generated for analysis. Five-year LC, DMFS, DFS and OS for stage pI vs. ypI groups were 96.7% vs. 96.4% (P=0.796), 92.7% vs. 73.6% (P=0.025), 91.2% vs. 73.6% (P=0.080) and 93.1% vs. 72.3% (P=0.040), respectively. In the DDS-favorable subset of the ypI group, LC, DMFS, DFS and OS resulted in no significant differences in comparison with the pI group (P=0.384, 0.368, 0.277 and 0.458, respectively).

Conclusions

LC was comparable in both groups; however, distant metastasis developed more frequently in down-staged LARC than de novo early stage cases, reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response. DDS can be an indicator to identify a subset of the ypI group whose long-term oncologic outcomes are as good as those of stage pI cohort.

Prognostic significance of neoadjuvant rectal score in locally advanced rectal cancer after neoadjuvant chemoradiotherapy and construction of a prediction model

AIM

To evaluate the prognostic significance of neoadjuvant rectal (NAR) score after neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC), and to develop a nomogram predicting disease-free survival (DFS).

METHOD

A total of 522 LARC patients undergoing nCRT and surgery were included. NAR scores were calculated using the equation [5pN-3(cT-pT) + 12]^2/9.61, and classified as low (<8), intermediate (8-16), and high (>16). Clinicopathological and survival outcomes were compared. Cox regression analysis was performed to identify risk factors of DFS. A predicting nomogram was developed and validated internally.

RESULTS

For NAR score classification, 193 (37.0%) were low, 183 (35.0%) were intermediate, and 146 (28.0%) were high. Higher NAR score was associated with fewer pCR, lower tumor regression grade (TRG), and higher ypTNM stage. A total of 5-year DFS for low, intermediate, and high NAR groups was 85.6%, 71.9%, and 47.2%, respectively (P < 0.001). NAR score (HR = 2.488, P = 0.002), TRG (HR = 2.811, P = 0.047), CRM involvement (HR = 2.703, P = 0.002), and IMA nodal metastasis (HR = 2.441, P = 0.001) were independent prognostic factors of DFS. A predicting nomogram was developed with C-index of 0.701.

CONCLUSION

NAR score could help in predicting DFS after nCRT. A nomogram was developed to identify subpopulations with aggressive tumors during clinical decision-making.

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

Background

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

Patients and methods

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

Results

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

Conclusions

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

Outcomes of neoadjuvant chemoradiotherapy followed by total mesorectal excision surgery for locally advanced rectal cancer: a single-institution experience

INTRODUCTION

Neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision (TME) surgery for locally advanced rectal cancer has been shown to improve local control and reduce toxicity, as compared to adjuvant CRT. We reported the outcomes of our patients with locally advanced rectal cancer treated at National University Hospital, Singapore.

METHODS

From April 2002 to December 2014, 117 patients with T3/4, N0/+, M0 rectal cancer received neoadjuvant CRT followed by TME surgery. The treatment regimen comprised a total radiotherapy dose of 50.4 Gy in 28 daily fractions delivered concurrently with 5-fluorouracil or capecitabine chemotherapy over 5.5 weeks. All patients were planned for TME surgery. Local control, disease-free survival, overall survival and treatment toxicities were analysed.

RESULTS

Median follow-up was 34 (range 2-122) months. 11.5% (13/113) of patients achieved a pathological complete response (pCR) and 72.6% (85/117) had either tumour or nodal downstaging following neoadjuvant CRT. 5.2% (5/96) of patients had Grade 3 acute toxicities (dermatitis and diarrhoea) and 3.1% (3/96) had Grade 3 late toxicities (fistula and stricture). There was no Grade 4 toxicity noted. The five-year local recurrence, disease-free survival and overall survival rates were 4.5%, 65.7% and 80.6%, respectively. Multivariate analysis showed that nodal positivity was a predictor of poor disease-free survival and poor overall survival. Tumour downstaging and pCR did not improve outcomes.

CONCLUSION

Our outcomes were comparable to internationally published data, and this treatment regimen remains the standard of care for locally advanced rectal cancer in our local population.

Treatment outcomes regarding the addition of targeted agents in the therapeutic portfolio for stage II-III rectal cancer undergoing neoadjuvant chemoradiation

Background

To evaluate the impact of targeted agents in stage II-III rectal cancer undergoing neoadjuvant concurrent chemoradiation therapy (CCRT).

Method

A retrospective study was performed in 124 consecutive patients with clinically T₃N_0-2M₀-staged rectal cancer incorporating targeted agents in CCRT.

Results

Pathologic complete response was detected in 34.2% (n=26) of bevacizumab+FOLFOX-treated patients (n=76), which was significantly higher (p=0.019, post-hoc statistical power =35.87%) than that (n=10, 20.8%) of the cetuximab+FOLFOX-treated patients (n=48). Patients receiving cetuximab+FOLFOX therapy tended to develop severe liver toxicity (91.7%, n=44 versus 17.1%, n=13, p<0.0001), as evaluated by morphologic grading of hepatic steatosis and sinusoidal dilatation in laparoscopy. In the 57 patients with morphologically severe liver toxicity, 36 (63.2%) retained a normal liver function; for the remaining 21 patients with an abnormal liver function, the abnormality was self-limited in 19 patients, whereas 2 cetuximab–treated patients progressed to hepatic failure and mortality. A subset analysis within bevacizumab+FOLFOX-treated patients with either wild-type (n=36) or mutant (n=40) K-ras status indicated K-ras status did not significantly influence the treatment outcomes.

Conclusions

The addition of bevacizumab instead of cetuximab to FOLFOX in the neoadjuvant settings for T₃N_0-2M₀-staged rectal cancer could induce a promising rate of pathologic complete response and lesser hepatotoxicity.

Simvastatin enhances radiation sensitivity of colorectal cancer cells

INTRODUCTION

Neoadjuvant chemoradiation (CRT) for rectal cancer induces variable responses, and better response has been associated with improved oncologic outcomes. Our group has previously shown that the administration of HMG-CoA reductase inhibitors, commonly known as statins, is associated with improved response to neoadjuvant CRT in rectal cancer patients. The purpose of this study was to study the effects of simvastatin on colorectal cancer cells and explore its potential as a radiation-sensitizer in vitro.

METHODS

Four colorectal cancer cell lines (SW480, DLD1, SW837, and HRT18) were used to test the effects of simvastatin alone, radiation alone, and combination therapy. Outcome measures included ATP-based cell viability, colony formation, and protein (immunoblot) assays.

RESULTS

The combination of radiation and simvastatin inhibited colony formation and cell viability of all four CRC lines, to a greater degree than either treatment alone (p < 0.01). In addition, the effects of simvastatin in this combination therapy were dose dependent, with increased concentrations resulting in more potentiated inhibitory effects. The radiosensitizing effects of simvastatin on cell viability were negated by the presence of exogenous GGPP in the media. On protein analyses of irradiated cells, simvastatin treatment inhibited phosphorylation of ERK1/2, in a dose-dependent manner, while the total levels of ERK1/2 remained stable. In addition, the combined treatment resulted in increased levels of cleaved caspase 3, indicating greater apoptotic activity in the cells treated with radiation and simvastatin together.

CONCLUSIONS

Treatment with simvastatin hindered CRC cell viability and enhanced radiation sensitivity in vitro. These effects were tied to the depletion of GGPP and the decreased phosphorylation of ERK1/2, suggesting a prominent role for the EGFR-RAS-ERK1/2 pathway, through which statin enhances radiation sensitivity.

Tumor Regression Grade After Neoadjuvant Chemoradiation and Surgery for Low Rectal Cancer Evaluated by Multiple Correspondence Analysis: Ten Years as Minimum Follow-up

BACKGROUND

The role of Mandard's tumor regression grade (TRG) classification is still controversial in defining the prognostic role of patients who have undergone neoadjuvant chemoradiation (CRT) and total mesorectal excision. The present study evaluated multiple correspondence analysis (MCA) as a tool to better cluster variables, including TRG, for a homogeneous prognosis.

PATIENTS AND METHODS

A total of 174 patients with a minimum follow-up period of 10 years were stratified into 2 groups: group A (TRG 1-3) and group B (TRG 4-5) using Mandard's classification. Overall survival and disease-free survival were analyzed using univariate and multivariate analysis. Subsequently, MCA was used to analyze TRG plus the other prognostic variables.

RESULTS

The overall response to CRT was 55.7%, including 13.2% with a pathologic complete response. TRG group A correlated strictly with pN status (P = .0001) and had better overall and disease-free survival than group B (85.1% and 75.6% vs. 71.1% and 67.3%; P = .06 and P = .04, respectively). The TRG 3 subset (about one third of our series) showed prognostically heterogeneous behavior. In addition to multivariate analysis, MCA separated TRG 1 and TRG 2 versus TRG 4 and TRG 5 well and also allocated TRG 3 patients close to the unfavorable prognostic variables.

CONCLUSION

TRG classification should be used in all pathologic reports after neoadjuvant CRT and radical surgery to enrich the prognostic profile of patients with an intermediate risk of relapse and to identify patients eligible for more conservative treatment. Thus, MCA could provide added value.

Applicability of American Joint Committee on Cancer and College of American Pathologists Regression Grading System in Rectal Cancer

BACKGROUND

Different tumor grading systems have been proposed to predict the association between tumor response and clinical outcome after preoperative chemoradiotherapy in patients with rectal cancer. The American Joint Committee on Cancer and College of American Pathologists regression grading system was recommended as the standard tumor regression grading system for rectal adenocarcinoma.

OBJECTIVE

This study evaluated the clinical applicability of the American Joint Committee on Cancer and College of American Pathologists regression grading system in neoadjuvant-treated patients with rectal cancer.

DESIGN

This is a retrospective cohort study based on clinical data from a prospectively maintained colorectal cancer database.

SETTINGS

This study was performed at a single tertiary referral center.

PATIENTS

A total of 144 patients with primary locally advanced mid-to-low rectal adenocarcinoma who underwent preoperative long-course chemoradiotherapy and total mesorectal excision between 2003 and 2012 were included.

MAIN OUTCOMES MEASURES

The primary outcome measures were the 5-year overall survival rate, the relapse-free survival rate, the cancer-specific survival rate, and cumulative recurrence rates.

RESULTS

Of the 144 patients, 16 (11%) were diagnosed as American Joint Committee on Cancer and College of American Pathologists regression grade 0, 43 patients (30%) as grade 1, 61 patients (42%) as grade 2, and 25 patients (17%) as grade 3.After a median follow-up time of 83 months (range, 3 to 147 mo), 5-year survival estimates for grades 0, 1, 2, and 3, were 93%, 77%, 81%, and 54% for overall survival (p = 0.006); 93%, 82%, 75%, and 55% for relapse-free survival (p = 0.03); and 100%, 86%, 89%, and 63% for cancer-specific survival (p = 0.006). The multivariate Cox regression analyses confirmed the American Joint Committee on Cancer and College of American Pathologists regression grading system as a prognostic factor for overall (p = 0.04), relapse-free (p = 0.02), and cancer-specific survival (p = 0.04).

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

Our study findings confirm the clinical relevance and applicability of the American Joint Committee on Cancer and College of American Pathologists regression grade system as a predictive factor for patients with rectal cancer. See Video Abstract at http://links.lww.com/DCR/A320.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Delayed versus immediate surgery following short-course neoadjuvant radiotherapy in resectable (T3N0/N+) rectal cancer

PURPOSE

Preoperative short-course radiotherapy (SCRT) followed by surgery has shown advantage over surgery alone in patients with resectable rectal carcinoma (RC); however, the importance of the timing of surgery after SCRT has not been well defined. This study aimed to investigate the effect of this duration on treatment outcomes.

METHODS

Patients who underwent surgery after SCRT (25 Gy/500 cGy/daily/5fr, monday-friday) for resectable and infraperitoneal rectal adenocarcinoma (T3N0/(+)) were included into the study. Patients were divided into two groups in terms of the timing of surgery: delayed surgery (>4 weeks) or immediate surgery (<4 weeks).

RESULTS

A hundred and thirty-six patients were included in the study. Median time between RT and surgery was 4 ± 5.7 (1-58) weeks, where 68% (n = 93) patients underwent delayed surgery (≥4 weeks). The two groups did not differ in terms of surgical margin positivity, pathological tumor regression, N downstaging, or T downstaging (p > 0.05 for all). However, the number of positive lymph nodes was higher in the immediate surgery group [median 3 (0-18) vs. 1 (0-17), p = 0.009]. Median follow-up time was 36 ± 9 (6-93) months. Delayed surgery group had significantly longer mean overall survival (p = 0.038); however, the two groups did not differ in terms of local recurrence, mean time to local recurrence, or mean disease-free survival.

CONCLUSIONS

Our findings seem to support the benefit of a longer time interval between radiotherapy and surgery after short-course neoadjuvant radiotherapy in resectable rectal cancer in terms of overall survival. However, there is a need to better define patient characteristics that might benefit from delayed surgery.

Does residual microscopic disease after chemoradiotherapy for locally advanced rectal cancer translate into a good clinical outcome?

AIM

This study aimed to assess the progression-free and overall survival of patients with residual microscopic disease following neoadjuvant chemoradiotherapy and rectal resection for locally advanced rectal cancer.

METHOD

Two-hundred and thirty-four consecutive rectal cancer patients who had neoadjuvant chemoradiotherapy followed by radical resection (from May 2000 to April 2012) were divided according to pathological tumour response: residual microscopic disease (MIC), complete response (pCR) and partial/no response (non-CR). Data on the neoadjuvant regime, treatment-to-surgery interval, final pathology, type of operation, operative time, postoperative complications, length of hospital stay, disease recurrence and mortality were compared between the groups.

RESULTS

There were 13 (5.5%) MIC patients, 48 (20.5%) with pCR and 173 (73.9%) with non-CR group. The groups were demographically comparable. MIC patients had more retrieved lymph nodes compared with the non-CR and pCR patients (median 13 compared with 8 and 10, respectively, P = 0.0086). The 5-year overall survival rates were 93.4% for the pCR and MIC patients vs 82.1% for the non-CR patients (P = 0.0324). The 5-year progression-free survival was 85.2% for the pCR and MIC patients vs 73.8% for the non-CR patients (P = 0.086).

CONCLUSION

We have identified and assessed a new pathological subgroup of rectal cancer patients who had residual microscopic disease after neoadjuvant therapy. The survival analysis aligned them closely with pCR patients.

Prognostic Role of Neutrophil-to-Lymphocyte Ratio in Locally Advanced Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy

Background

Increasing evidence suggests that cancer-associated inflammation is associated with poorer outcomes. The neutrophil-to-lymphocyte ratio (NLR), considered as a systemic inflammation marker, is thought to predict prognoses in colorectal cancer. In this study, we explored the association between the NLR and prognoses following neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC).

Material/Methods

From February 2002 to December 2012, a group of 202 patients diagnosed with LARC and receiving neoadjuvant CRT followed by radical surgery was included in our retrospective study. The associations between the pre-CRT NLR and clinicopathological characteristics, as well as the predictive value of pre-CRT NLR against survival outcomes, were analyzed.

Results

The average NLR was 2.7±1.5 (median 2.4, range 0.6–12.8). There were 63 (31.2%) patients with NLR ≥3.0, and 139 (68.8%) patients with NLR <3.0. Correlation analyses showed that no clinicopathological characteristics except age were associated with NLR. We did not find an association between NLR and survival outcomes. In multivariate Cox model analyses, the R1/R2 resection, lymph node ratio ≥0.1, and perineural/lymphovascular invasion were independently associated with worse disease-free survival and overall survival.

Conclusions

In our cohort, the NLR did not correlate with survival outcomes in LARC patients undergoing neoadjuvant CRT. The prognostic value of NLR should be validated in large-scale prospective studies.