Adjuvant postoperative radiotherapy and chemotherapy in rectal carcinoma: a review of the Gastrointestinal Tumor Study Group experience

The Role of Intraoperative Radiotherapy Treatment of Locally Advanced Rectal Cancer

Intraoperative radiation therapy (IORT) has been used in the treatment of locally advanced and recurrent rectal cancers for the last several decades. Given the heterogeneity of patients treated and different indications for use and dosing at different institutions, it has been difficult to discern if IORT adds any appreciable benefit to standard of care therapies. Herein, the rationale for IORT in rectal cancer is discussed along with the most modern and best available data in 2023. IORT is likely indicated in patients with locally advanced and locally recurrent rectal cancer with threatened margins (R0 or R1 resection) to help improve local control. High-quality imaging and multidisciplinary discussion are necessary to ensure optimal patient selection. Appropriate counseling of the patient and excellent team communication are of the utmost importance given the challenging nature of these cases and the prognostic implications of R1 and R2 resections in this patient population.

Surgical Outcomes after Radiotherapy in Rectal Cancer

Over the past decade, the treatment of rectal cancer has changed considerably. The implementation of TME surgery has, in addition to decreasing the number of local recurrences, improved surgical morbidity and mortality. At the same time, the optimisation of radiotherapy in the preoperative setting has improved oncological outcomes even further, although higher perineal infection rates have been reported. Radiotherapy regimens have evolved through the adjustment of radiotherapy techniques and fields, increased waiting intervals, and, for more advanced tumours, adding chemotherapy. Concurrently, imaging techniques have significantly improved staging accuracy, facilitating more precise selection of advanced tumours. Although chemoradiotherapy does lead to the downsizing and -staging of these tumours, a very clear effect on sphincter-preserving surgery and the negative resection margin has not been proven. Aiming to decrease distant metastasis and improve overall survival for locally advanced rectal cancer, systemic chemotherapy can be added to radiotherapy, known as total neoadjuvant treatment (TNT). High complete response rates, both pathological (pCR) and clinical (cCR), are reported after TNT. Patients who follow a Watch & Wait program after a cCR can potentially avoid surgical morbidity and colostomy. For both early and more advanced tumours, trials are now investigating optimal regimens in an attempt to offer organ preservation as much as possible. Multidisciplinary deliberation should include patient preference, treatment toxicity, and likelihood of end colostomy, but also the burden of intensive surveillance in a W&W program.

The impact of intensity-modulated radiotherapy in conjunction with chemotherapy on proximal pT3N0 rectal cancer patients after total mesorectum excision

BACKGROUND

This study aimed to ascertain if the incorporation of intensity-modulated radiotherapy (IMRT) with chemotherapy (CTx) offered any advantages for patients diagnosed with stage pT3N0 rectal cancer located in the proximal (upper) region following a complete total mesorectum excision (TME).

METHODS

We retrospectively examined medical records of stage II/III rectal cancer patients who had undergone CTx or concurrent chemoradiation (CCRT) with IMRT after a successful TME. We juxtaposed a variety of survival outcomes across two patient cohorts. Each outcome was further classified according to Gunderson's risk stratification between proximal and distal (middle and low) rectal cancer patients, and we evaluated the factors associated with each outcome.

RESULTS

The median follow-up duration was 4.9 years. Our research comprised 236 rectal adenocarcinoma patients treated at our institution between 2007 and 2019. They received either the CTx (n = 135) or the CCRT (n = 101) with 10-year locoregional recurrence-free survival (LRRFS) of 90.1% and 96.1%, respectively (p = 0.163). However, after performing multivariate adjustments, a pattern emerged hinting at a better LRRFS for the CCRT group (p = 0.052). Perforation had a strong correlation with locoregional recurrence. No significant differences were observed in other survival between the two treatment arms and their respective subgroups. The CCRT group witnessed significantly higher immediate and chronic complications with p = 0.007 and 0.009, respectively. The CCRT group had two secondary cancer-related fatalities (2%, one attributed to IMRT), and another reported by the CTx group (1%). The sole classified locoregional recurrence within the cohort of 37 individuals treated with CTx for proximal pT3N0 rectal cancer was, in fact, the development of sigmoid colon cancer.

CONCLUSION

The results suggest that for patients with proximal pT3N0 rectal cancer post-TME, IMRT is better when not combined with CTx, except in highly perilous scenarios or those involving perforation.

Report from the 24th Annual Western Canadian Gastrointestinal Cancer Consensus Conference on Colorectal Cancer, Richmond, British Columbia, 28-29, October 2022

The 24th annual Western Canadian Gastrointestinal Cancer Consensus Conference (WCGCCC) was held in Richmond, British Columbia, on 28-29 October 2022. The WCGCCC is an interactive multidisciplinary conference attended by healthcare professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals such as dieticians, nurses and a genetic counsellor participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

Current status of locally advanced rectal cancer therapy and future prospects

Rectal cancer treatment has been evolving ever since the beginning of the 20th century. Surgery was originally the only available method regardless of the extent of tumor invasion or nodal involvement status. Total mesorectal excision was established as the standard procedure in the early 1990s. Advances in the utilization of radiation for rectal cancer led to the addition of radiotherapy (RT) combined with chemotherapy to the postoperative treatment algorithm. The promising results of the Swedish short-course preoperative RT set the basis for a number of large randomized trials investigating the efficacy of neoadjuvant RT or chemoradiotherapy (CRT) for advanced rectal cancer. Both short-course RT and long-course preoperative CRT compared favorably to adjuvant treatment and became the standard of choice for patients with extramural invasion or lymph node involvement. Recently, the focus of clinical research has been shifted towards total neoadjuvant therapy (TNT), delivering the whole course of RT and chemotherapy before surgery, and showing good tolerance and encouraging efficacy. Although targeted therapies haven't displayed a benefit in the neoadjuvant setting, preliminary evidence suggests impressive efficacy of immunotherapy in rectal carcinomas with mismatch-repair deficiency. In this review, we provide an in-depth critical overview of all significant randomized trials that have shaped the current treatment guidelines for locally advanced rectal cancer and discuss future trends for the treatment of this common malignancy.

Advances in Radiotherapy for Rectal Cancer

The current preferred standard of care management for patients with locally advanced rectal cancer is total neoadjuvant therapy, in which all chemotherapy and radiotherapy is delivered before surgery. Within this approach, developed in response to persistently high distant failure rates despite excellent local control with preoperative chemoradiotherapy, there remains questions regarding the optimal radiotherapy regimen (short course vs long course) and sequencing of chemotherapy (induction vs consolidation).

A systematic review and network meta-analysis of randomised controlled trials comparing neoadjuvant treatment strategies for stage II and III rectal cancer

AIM

Multiple neoadjuvant therapy strategies have been used and compared for rectal cancer and there has been no true consensus as to the optimal neoadjuvant therapy regimen. The aim is to identify and compare the neoadjuvant therapies available for stage II and III rectal cancer.

DESIGN

A systematic literature review was performed, from inception to August 2022, of the following databases: MEDLINE, EMBASE, Science Citation Index Expanded, Cochrane Library. Only randomized controlled trials comparing neoadjuvant therapies for stage II and III rectal cancer were considered. Stata was used to draw network plots, and a Bayesian network meta-analysis was conducted through models utilizing the Markov Chain Monte Carlo method in WinBUGS.

RESULTS

A total of 58 articles were included based on 41 randomised controlled trials, reporting on 12,404 participants that underwent 15 neoadjuvant treatment regimens. No significant difference was identified between treatments for major or total postoperative complications, anastomotic leak rates, or sphincter-saving surgery. Straight to surgery (STS) ranked as best treatment for preoperative toxicity but ranked worst treatment for positive resection margins and complete response. STS had significantly increased positive resection margins compared to long-course chemoradiotherapy with short-wait (LCCRT-SW) or long-wait (LCCRT-LW) to surgery, or short-course radiotherapy with short-wait (SCRT-SW) or immediate surgery (SCRT-IS). LCCRT-SW or LCCRT-LW resulted in significantly increased complete response rates compared to STS. LCCRT-LW significantly improved 2-year overall survival compared to STS, SCRT-IS, SCRT-SW. Total neoadjuvant therapy regimes with short-course radiotherapy followed by consolidation chemotherapy (SCRT-CT-SW), induction chemotherapy followed by long-course chemoradiotherapy (CT-LCCRT-S), long-course chemoradiotherapy followed by consolidation chemotherapy (LCCRT-CT-S), significantly improved positive resection margins, complete response, and disease-free survival compared to STS. Chemotherapy with monoclonal antibodies followed by long-course chemoradiotherapy (CT+MAB-LCCRT+MAB-S) significantly improved complete response and positive resection margins compared to STS, and 2-year disease-free survival compared to STS, SCRT-IS, SCRT-SW, SCRT-CT-SW, LCCRT-SW, LCCRT-LW. CT+MAB-LCCRT+MAB-S ranked as best treatment for disease-free survival and overall survival.

CONCLUSIONS

Conventional neoadjuvant therapies with short-course radiation or long-course chemoradiotherapy have oncological benefits compared to no neoadjuvant therapy without increasing perioperative complication rates. Prolonged wait to surgery may improve oncological outcomes. Total neoadjuvant therapies provide additional benefits in terms of complete response, positive resection margins, and disease-free survival. Monoclonal antibody therapy may further improve oncological outcomes but currently is only applicable to a small subgroup of patients and requires further validation.

Rectosigmoid Cancer-Rectal Cancer or Sigmoid Cancer?

OBJECTIVES

We aimed to determine the optimal treatment for patients with locally advanced rectosigmoid cancers, and to determine whether this can be guided by distance from anal verge (AV) and/or anatomic landmarks such as the sacral promontory and peritoneal reflection (PR).

MATERIALS AND METHODS

We retrospectively reviewed patients with T3-T4 and/or node-positive rectosigmoid cancers who underwent surgery from 2006 to 2018 with available pelvic imaging. We included tumors at 9 to 20 cm from the AV on either staging imaging, or colonoscopy. Patients were stratified into those who received neoadjuvant therapy, and those who underwent upfront surgery. Comparisons of characteristics were performed using χ 2 test and Fischer exact test. Locoregional failure (LRF) and overall survival were compared using Cox regressions and Kaplan-Meier analysis.

RESULTS

One hundred sixty-one patients were included. Ninety-seven patients had neoadjuvant therapy, and 64 patients had upfront surgery. Median follow-up time was 45.1 months. Patients who had neoadjuvant therapy had tumors that were higher cT stage ( P <0.01) with more positive/close circumferential resection margins seen on imaging by radiologists (28.9% vs. 1.6% , P =0.015). The 2-year rate of LRF, distant metastases, or overall survival was not significantly different between the 2 groups. None of 15 patients with tumors below the PR treated with neoadjuvant therapy had LRF, but 1 (25%) of 4 patients with tumors below the PR treated with adjuvant therapy experienced LRF ( P =0.05).

CONCLUSIONS

Patients with tumors below the PR may benefit more from neoadjuvant therapy. The PR on imaging may be a reliable landmark in addition to the distance from the AV to determine the most appropriate treatment option.

New Frontiers in Management of Early and Advanced Rectal Cancer

It is important to understand advances in treatment options for rectal cancer. We attempt to highlight advances in rectal cancer treatment in the form of a systematic review. Early-stage rectal cancer focuses on minimally invasive endoluminal surgery, with importance placed on patient selection as the driving factor for improved outcomes. To achieve a complete pathologic response, various neoadjuvant chemoradiation regimens have been employed. Short-course radiation therapy, total neoadjuvant chemotherapy, and others provide unique advantages with select patient populations best suited for each. With a clinical complete response, a "watch and wait" non-operative surveillance has been introduced with preliminary equivalency to radical resection. Various modalities for total mesorectal excision, such as robotic or transanal, have advantages and can be utilized in select patient populations. Tumors demonstrating solid organ or peritoneal spread, traditionally defined as unresectable lesions conveying a terminal diagnosis, have recently undergone advances in hepatic and pulmonary metastasectomy. Hepatic and pulmonary metastasectomy has demonstrated clear advantages in 5-year survival over standard chemotherapy. With the peritoneal spread of colorectal cancer, HIPEC with cytoreductive therapy has emerged as the preferred treatment. Understanding the various therapeutic interventions will pave the way for improved patient outcomes.

Survival analysis and prognostic factors of palliative radiotherapy in patients with metastatic colorectal cancer: a propensity score analysis

Background

Radiation therapy (RT) is known to have beneficial effects on the palliative treatment of patients with advanced cancer. However, valid data on this treatment method are limited, especially for patients with metastatic colorectal cancer (mCRC). This study aimed to identify prognostic factors and investigate the outcomes of mCRC patients who received palliative RT.

Methods

A total of 488 mCRC patients who underwent systemic therapy with or without palliative RT between 2014 and 2019 were included in the study. Of the 488 patients, 155 received systemic treatment combined with palliative RT (RT group), while 333 were only administered systemic treatment (non-RT group). Propensity score matching (PSM) was conducted to eliminate possible bias, and overall survival (OS) was calculated using the Kaplan-Meier (KM) method. A log-rank test was used to compare the survival outcomes of each group, and a multivariate analysis was conducted using a Cox proportional hazards model.

Results

The RT group had a higher OS than that of the non-RT group (P=0.001). After PSM, the median OS of the RT group was 50.8 months, and for the non-RT group it was 32.2 months (P=0.003). Subgroup analysis revealed that RT had a better effect on the OS of patients who had synchronous metastasis, or who didn't receive targeted therapy or local treatment (including surgery, ablation, and intervention). Multivariate analysis of the whole cohort showed that palliative RT was associated with improved OS. Moreover, multivariate analysis of the RT group showed that systemic therapy before RT, and the site of RT was in the liver and lung, were independent prognostic factors affecting survival time.

Conclusions

We demonstrated that systemic treatment followed by palliative RT led to a better OS for mCRC patients. This combination method can therefore be seen as a suitable treatment approach for patients with mCRC.

Current State of Neoadjuvant Radiotherapy for Rectal Cancer

Colorectal cancer is the third most commonly diagnosed cancer, with rectal cancer accounting for 30% of cases. The current standard of care curative treatment for locally advanced rectal cancer is (chemo)radiotherapy followed by surgery and adjuvant chemotherapy. Although neoadjuvant radiotherapy has reduced the risk of local recurrence to less than 10%, the risk of distant metastasis remained high at 30% affecting patient survival. In addition, there is a recognition that there is heterogeneity in tumor biology and treatment response with good responders potentially suitable for treatment de-escalation. Therefore, new treatment sequencing and regimens were investigated. Here, we reviewed the evidence for current neoadjuvant treatment options in patients with locally advanced rectal adenocarcinoma, and highlight the new challenges in this new treatment landscape.

Platelet-armored nanoplatform to harmonize janus-faced IFN-γ against tumor recurrence and metastasis

Interferon-γ (IFN-γ) plays contradictory roles in tumor immunology: (I) to activate positive host's immunity for eliminating tumor; (II) to induce negative adaptive immune resistance via up-regulating programmed death ligand-1 (PD-L1) expression for tumors to evade immune surveillance. The negative feedback loop between the IFN-γ recovery and the IFN-γ-induced PD-L1 up-regulation puts postoperative adjuvant chemotherapy into a dilemma. It is of great significance but challenging to manipulate the double-edge effects of IFN-γ against postoperative tumor progression. Herein, a platelet-engineered nanoplatform (PMF@DR NPs) capable of harmonizing janus-faced nature of IFN-γ was designed via uniquely co-assembling doxorubicin (Dox) and cyclin-dependent kinase 5 inhibitor roscovitine (Rosco) with platelet membrane fragment (PMF) as the particulate stabilizer. With PMF@DR NPs navigated by PMF to residual tumor, the Dox-activated immune response recovered IFN-γ secretion for positive host's immunity, while the IFN-γ-induced negative adaptive immune resistance was potently overcome by Rosco via disabling PD-L1 expression without dependence of IFN-γ stimulation. The negative feedback loop between IFN-γ recovery and PD-L1 up-regulation was thus potently disrupted in postoperative adjuvant chemotherapy. Our PMF@DR NPs not only harmonized janus-faced nature of IFN-γ to effectively regulate postoperative tumor progression, but also illustrated an innovative strategy for high-drug-loading biomimic nanoplatform.

A Systematic Review of the Cyclooxygenase-2 (COX-2) Expression in Rectal Cancer Patients Treated with Preoperative Radiotherapy or Radiochemotherapy

The main objective of this systematic review is to investigate the expression level of the cyclooxygenase-2 (COX-2) in rectal cancer treated with either preoperative radiotherapy or radiochemotherapy. In addition, we have summarized the effects of preoperative treatment of rectal cancer with regards to the expression levels of COX-2. A systematic literature review was performed in The Cochrane Library, PubMed, Web of Science, and Scopus databases on 1 January 2021 with the usage of the following search string-(cyclooxygenase-2) OR (COX-2) AND (rectal cancer) AND (preoperative radiochemotherapy) OR (preoperative radiotherapy). Among the 176 included in the analysis, only 13 studies were included for data extraction with a total number of 2095 patients. The results of the analysis are based on the articles concerning the expression of COX-2 in rectal cancer among patients treated with preoperative radiotherapy or radiochemotherapy. A COX-2 expression is an early event involved in rectal cancer development. In cases of negative COX-2 expression, radiotherapy and radiochemotherapy might contribute to the reduction of a local recurrence. Therefore, COX-2 may be considered as a biologic factor while selecting patients for more effective, less time-consuming and less expensive preoperative treatment. However, the utility of the administration of COX-2 inhibitors to patients with COX-2 overexpression, in an attempt to improve the patients' response rate to the neoadjuvant treatment, needs an assessment in further clinical trials.

Omission of or Poor Response to Preoperative Chemoradiotherapy Impacts Radial Margin Positivity Rates in Locally Advanced Rectal Cancer

BACKGROUND

In the setting of multidisciplinary standardized care of locally advanced rectal cancer, preoperative chemoradiotherapy and total mesorectal excision have become the mainstay treatment.

OBJECTIVE

This study aimed to evaluate whether the lack of preoperative chemoradiotherapy or poor response to it is associated with higher radial margin disease involvement in patients with locally advanced rectal cancer.

DESIGN

This is a retrospective cohort study using a publicly available database.

SETTING

Data were collected from the proctectomy-targeted National Surgical Quality Improvement Project file from 2016 to 2017.

PATIENTS

A total of 1161 patients were analyzed. They were categorized into 3 groups: patients who did not receive any preoperative chemoradiotherapy (28.6%), patients who received and responded to preoperative chemoradiotherapy (41.2%), and patients who received but did not respond to preoperative chemoradiotherapy (30.2%).

MAIN OUTCOME MEASURES

Response to treatment was determined by using the American Joint Committee on Cancer pretreatment and final pathological staging. Circumferential radial margin was extracted from the targeted proctectomy file.

RESULTS

Disease-involved positive circumferential radial margin was found in 86 (7.4%) cases. Positive radial margin was noted in 11 of 479 patients (2.3%) who underwent preoperative chemoradiotherapy and responded to treatment, 30 of 350 patients (8.6%) who did not respond or had a poor response to preoperative chemoradiotherapy, and 45 of 332 patients (13.6%) who did not receive preoperative chemoradiotherapy (p < 0.001). Regression analysis demonstrated that patients who do not receive preoperative chemoradiotherapy or have poor response to it have 6.6 and 4 times higher chances of having a positive radial margin.

LIMITATIONS

There is a risk of selection bias, unidentified confounders, and missing data despite the use of a nationwide cohort.

CONCLUSIONS

Omission of indicated preoperative chemoradiotherapy or poor response to it is associated with increased risk of radial margin positivity. More efforts are needed for standardized rectal cancer care with the appropriate use of preoperative chemoradiotherapy. See Video Abstract at http://links.lww.com/DCR/B467.

LA OMISIN O LA ESCASA RESPUESTA A QUIMIORADIOTERAPIA PREOPERATORIA, AFECTA LAS TASAS DE POSITIVIDAD DEL MARGEN RADIAL, EN EL CNCER RECTAL LOCALMENTE AVANZADO

ANTECEDENTES:En el contexto de la atención multidisciplinaria estandarizada del cáncer rectal localmente avanzado, la quimioradioterapia preoperatoria y la escisión mesorrectal total, se han convertido en el tratamiento principal.OBJETIVO:Evaluar si la omisión de quimioradioterapia preoperatoria o la escasa respuesta, se asocia con mayor enfermedad del margen radial, en pacientes con cáncer rectal localmente avanzado.DISEÑO:Estudio de cohorte retrospectivo utilizando una base de datos disponible públicamente.AJUSTE:Se recopilaron datos del archivo del Proyecto Nacional de Mejora de la Calidad Quirúrgica dirigido a la proctectomía de 2016-2017.PACIENTES:Se analizaron un total de 1161 pacientes. Clasificados en tres grupos: pacientes que no recibieron quimioradioterapia preoperatoria (28,6%), pacientes que recibieron y respondieron a quimioradioterapia preoperatoria (41,2%) y pacientes que recibieron pero no respondieron a la quimioradioterapia preoperatoria (30,2%).PRINCIPALES MEDIDAS DE RESULTADO:La respuesta al tratamiento se determinó utilizando el pre tratamiento y la estatificación patológica final, del American Joint Committee on Cancer. El margen radial circunferencial se extrajo del archivo de proctectomía dirigida.RESULTADOS:Se encontró enfermedad que abarcaba el margen radial circunferencial +, en el 86 (7,4%) casos. Se observó el margen radial +, en 11 de 479 pacientes (2,3%) que se sometieron a quimioradioterapia preoperatoria y respondieron al tratamiento, 30 de 350 pacientes (8,6%) que no respondieron o tuvieron una mala respuesta con quimioradioterapia preoperatoria y en 45 de 332 pacientes (13,6%) que no recibieron quimioradioterapia preoperatoria (p <0,001). El análisis de regresión demostró que los pacientes que no reciben quimioradioterapia preoperatoria o que tienen escasa respuesta, presentan respectivamente, 6,6 y 4 veces más probabilidades de tener un margen radial +.LIMITACIONES:Existe el riesgo de sesgo de selección, factores de confusión no identificados y datos faltantes a pesar del uso de una cohorte nacional.CONCLUSIONES:La omisión de la quimioradioterapia preoperatoria indicada o la escasa respuesta, se asocian a un mayor riesgo de positividad del margen radial. Se necesitan mayores esfuerzos en la atención estandarizada del cáncer rectal, con el uso adecuado de quimioradioterapia preoperatoria. Consulte Video Resumen en http://links.lww.com/DCR/B467.

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.

Estimating Population-Based Recurrence Rates of Colorectal Cancer over Time in the United States

BACKGROUND

Population-based metastatic recurrence rates for patients diagnosed with nonmetastatic colorectal cancer cannot be estimated directly from population-based cancer registries because recurrence information is not reported. We derived population-based colorectal cancer recurrence rates using disease-specific survival data based on our understanding of the colorectal cancer recurrence-death process.

METHODS

We used a statistical continuous-time multistate survival model to derive population-based annual colorectal cancer recurrence rates from 6 months to 10 years after colorectal cancer diagnosis using relative survival data from the Surveillance, Epidemiology, and End Results Program. The model was based on the assumption that, after 6 months of diagnosis, all colorectal cancer-related deaths occur only in patients who experience a metastatic recurrence first, and that the annual colorectal cancer-specific death rate among patients with recurrence was the same as in those diagnosed with de novo metastatic disease. We allowed recurrence rates to vary by post-diagnosis time, age, stage, and location for two diagnostic time periods.

RESULTS

In patients diagnosed in 1975-1984, annual recurrence rates 6 months to 5 years after diagnosis ranged from 0.054 to 0.060 in stage II colon cancer, 0.094 to 0.105 in stage II rectal cancer, and 0.146 to 0.177 in stage III colorectal cancer, depending on age. We found a statistically significant decrease in colorectal cancer recurrence among patients diagnosed in 1994-2003 compared with those diagnosed in 1975-1984 for 6 months to 5 years after diagnosis (hazard ratios between 0.43 and 0.70).

CONCLUSIONS

We derived population-based annual recurrence rates for up to 10 years after diagnosis using relative survival data.

IMPACT

Our estimates can be used in decision-analytic models to facilitate analyses of colorectal cancer interventions that are more generalizable.

Challenges of improving treatment outcomes for colorectal and anal cancers in Japan: the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG)

Colorectal cancer is a major public health concern in Japan. While early-stage colorectal adenocarcinoma treatment entails radical resection of the primary tumor, the importance of perioperative treatment is growing as physicians seek to further improve treatment outcomes. For anal squamous cell carcinoma, definitive chemoradiotherapy is superior to radical surgery in terms of improved patient quality of life. The Colorectal Cancer Study Group of the Japanese Clinical Oncology Group was established in 2001 and has worked to provide answers to common clinical questions and improve treatment outcomes for colorectal and anal cancers through 15 large-scale prospective clinical trials. Here, we discuss the current state of perioperative treatment for early-stage colon, rectal and anal cancers in Japan and approaches taken by the Colorectal Cancer Study Group/the Japanese Clinical Oncology Group to improve treatment outcomes for these cancers.

Are Community Hospitals Meeting the Same Standards as Academic Hospitals for the Multimodal Management of Rectal Cancer?

Although multimodal treatment (surgery, chemotherapy ± radiation) has improved survival in patients with rectal cancer, there are inconsistent treatment patterns in hospitals in the United States. The objective of the study was to evaluate whether treatment paradigms have changed for patients with Stage II and III rectal cancer in community hospitals compared with academic research hospitals, i.e., teaching or comprehensive hospitals engaged in research. The National Cancer Database was queried to identify all patients diagnosed with Stage II or III rectal adenocarcinoma between 2000 and 2008. The first course of treatment and patient clinicodemographic factors were evaluated. Of 70,409 patients in the study cohort, 7,235 (62.9%) at community hospitals, 24,465 (66.9%) at comprehensive hospitals, and 14,868 (66.6%) at teaching hospitals received multimodal therapy. Community hospitals were more likely to treat individuals who were older, white, and with lower income compared with the other facility types. Teaching hospitals treated a higher proportion of uninsured patients. Despite differences in patient demographics, community hospitals have increased the use of multimodal treatment for rectal cancer but continue to remain below academic research hospital standards.

Controversies in Rectal Cancer Treatment and Management

Incorporation of new treatment modalities has significantly increased the complexity of the treatment and management of rectal cancer, including perioperative therapy for local advanced disease and organ preservation for those with response to the preoperative treatment. This review may help practitioners better understand the rationale and selection.

Adjuvant chemotherapy for rectal cancer: Current evidence and recommendations for clinical practice

While adjuvant chemotherapy is an established treatment for pathological stage II and especially stage III colon cancer, its role in the multimodal management of rectal cancer remains controversial. As a result, there is substantial variation in the use of this treatment in clinical practice. Even among centres and physicians who consider adjuvant chemotherapy as a standard treatment, notable heterogeneity exists with regard to patient selection criteria and chemotherapy regimens. The controversy around this topic is confirmed by the lack of full consensus among national and international clinical guidelines. While most of the clinical trials do not support the contention that adjuvant chemotherapy may improve survival outcomes if pre-operative (chemo)radiotherapy is also given, these suffer from many limitations that preclude drawing definitive conclusions. Nevertheless, in the era of evidence-based medicine, physicians should be guided by the available data and refrain from extrapolating results of adjuvant colon cancer trials to inform treatment decisions for rectal cancer. Patients should be informed of the evidence gap, be given the opportunity to carefully discuss pros and cons of all the possible management options and be empowered in the decision making. In this article we review the available evidence on adjuvant chemotherapy for rectal cancer and propose a risk-adapted decisional algorithm that largely relies on informed patient preferences.

Association Between Adjuvant Chemotherapy and Overall Survival in Patients With Rectal Cancer and Pathological Complete Response After Neoadjuvant Chemotherapy and Resection

Importance

Although American guidelines recommend use of adjuvant chemotherapy in patients with locally advanced rectal cancer, individuals who achieve a pathological complete response (pCR) following neoadjuvant chemoradiotherapy are less likely to receive adjuvant treatment than incomplete responders. The association and resection of adjuvant chemotherapy with survival in patients with pCR is unclear.

Objective

To determine whether patients with locally advanced rectal cancer who achieve pCR after neoadjuvant chemoradiation therapy and resection benefit from the administration of adjuvant chemotherapy.

Design, Setting, and Participants

This retrospective propensity score-matched cohort study identified patients with locally advanced rectal cancer from the National Cancer Database from 2006 through 2012. We selected patients with nonmetastatic invasive rectal cancer who achieved pCR after neoadjuvant chemoradiation therapy and resection.

Exposures

We matched patients who received adjuvant chemotherapy to patients who did not receive adjuvant treatment in a 1:1 ratio. We separately matched subgroups of patients with node-positive disease before treatment and node-negative disease before treatment to investigate for effect modification by pretreatment nodal status.

Main Outcome and Measures

We compared overall survival between groups using Kaplan-Meier survival methods and Cox proportional hazards models.

Results

We identified 2455 patients (mean age, 59.5 years; 59.8% men) with rectal cancer with pCR after neoadjuvant chemoradiation therapy and resection. We matched 667 patients with pCR who received adjuvant chemotherapy and at least 8 weeks of follow-up after surgery to patients with pCR who did not receive adjuvant treatment. Over a median follow-up of 3.1 years (interquartile range, 1.94-4.40 years), patients treated with adjuvant chemotherapy demonstrated better overall survival than those who did not receive adjuvant treatment (hazard ratio, 0.44; 95% CI, 0.28-0.70). When stratified by pretreatment nodal status, only those patients with pretreatment node-positive disease exhibited improved overall survival with administration of adjuvant chemotherapy (hazard ratio, 0.24; 95% CI, 0.10-0.58).

Conclusions and Relevance

The administration of adjuvant chemotherapy in patients with rectal cancer with pCR is associated with improved overall survival, particularly in patients with pretreatment node-positive disease. Although this study suggests a beneficial effect of adjuvant treatment on survival in patients with pCR, these results are limited by the presence of potential unmeasured confounding in this nonrandomized study.

Total neoadjuvant therapy in locally advanced rectal cancer: Role of systemic chemotherapy

For the past several decades, disease-related outcomes, particularly local recurrence rate, in patients with locally advanced rectal cancer have significantly improved as a result of advancement of surgical technique and implementation of neoadjuvant chemoradiation. However, distant metastasis remains unresolved, being a significant cause of cancer death. To focus on micrometastases early in the course of multimodal treatment, delivering systemic chemotherapy in the neoadjuvant setting is emerging. Also, driven by patient demand and interest in preserving quality of life, upfront chemotherapy prior to surgery serves as a strategy for organ preservation in the management of rectal cancer. Herein, currently available literature on different methods and strategies of the multimodal approach is critically appraised.

Adjuvant radiation therapy for T4 non-rectal colon adenocarcinoma provides a cause-specific survival advantage: A SEER database analysis

PURPOSE

While there is no level 1 evidence supporting the use of adjuvant radiotherapy (RT) for non-rectal colon cancer in the modern chemotherapy era, there are studies that suggest a local control benefit. This treatment modality is not part of standard treatment recommendations, and we hypothesized that adjuvant RT provides a benefit in locally advanced disease. Due to the limited number who receive post-operative RT, a national database was searched to provide sufficient power.

MATERIALS AND METHODS

A retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database was performed. Inclusion criteria were: non-rectal colon cancer, AJCC 6th or 7th edition T4 and M0, oncologic resection, and 1st cancer site. Patients were excluded for RT prior to or during surgery, or if the sequence of RT was unknown. Using a Cox proportional hazard model, the relative risk of cause-specific mortality for "RT after surgery" versus "No RT" was calculated.

RESULTS

21,789 patients were identified who met the inclusion criteria. Of these, only 1001 received adjuvant RT, and 64% were node-positive (53% RT vs. 65% no RT). When comparing RT vs. no RT, after adjusting for sex, age, N stage, and grade, we determined the relative risk of death from cancer was 0.8849 (95% CI: 0.8008-0.9779; p = 0.0165), suggesting that only 14 patients with T4 disease need receive adjuvant radiation to spare a cancer-related death.

CONCLUSIONS

Adjuvant RT is not routinely utilized for definitive treatment of T4 non-rectal colon cancer, but this analysis shows a significant cause-specific survival benefit.

Combination of primary tumor location and mismatch repair status guides adjuvant chemotherapy in stage II colon cancer

Background

Current opinions on the benefits of adjuvant chemotherapy for stage II colon cancer are divided and reformative election of these patients is required. We examined whether the primary tumor location based on mismatch repair status and other risk factors could better inform the current guideline.

Materials and Methods

A total of 673 consecutive patients with stage II colon cancer were included in the analysis. Differences in the common clinicopathological factors between left-sided colon cancer and right-sided colon cancer were analyzed using Fisher's exact analysis. Kaplan-Meier analysis was used to distinguish the survival difference by primary tumor location and/or MMR status.

Results

RCC had a shorter overall survival (P = 0.001) and Disease-free survival (P = 0.050) than LCC but was associated with survival benefit from adjuvant chemotherapy (P = 0.001 and P = 0.011 for OS and DFS, respectively). Mismatch repair-proficient had a shorter OS (P = 0.036) and disease free survival (P = 0.034) than mismatch-repair deficient but chemotherapy improved the OS (P = 0.007). When the primary tumor location and MMR status were combined, the PMMR/RCC was the only subgroup that could benefit from adjuvant chemotherapy (P < 0.001 and P = 0.002 for OS and DFS, respectively). Other tumors such as DMMR/RCC, DMMR/LCC, and PMMR/LCC did not benefit.

Conclusions

The observed survival benefits in PMMR/RCC patients treated with adjuvant chemotherapy will allow better selection of patients for chemotherapy who are in stage II.

Neoadjuvant Treatment for Locally Advanced Rectal Cancer: New Concepts in Clinical Trial Design

OPINION STATEMENT

Treatment for locally advanced rectal cancer has evolved from surgery alone to surgery plus adjuvant therapy. Preoperative 5-fluorouracil- or capecitabine-based chemoradiation with standard fractionated radiation, surgery utilizing total mesorectal excision, and further chemotherapy has become the standard of care in the USA. Preoperative adjuvant chemoradiation treatment sequencing has allowed for decreased toxicity, more sphincter-sparing surgery, and improved local control rates as compared to delivering the chemoradiation postoperatively. Yet, given the heterogeneity of locally advanced disease, some patients may be over-treated with this approach, leading to unnecessary toxicity and costs, while others may have a propensity to develop distant metastases and may benefit from intensified therapy. Therefore, the trend in modern clinical trial design has been to individualize therapy. As such, current studies are examining shortening the duration of radiation, omitting preoperative chemoradiation in patients who have a robust response to induction chemotherapy alone, omitting or delaying surgery in patients who have a clinical complete response to preoperative chemoradiation, and completing all of the adjuvant treatment prior to surgery.

Evolving Role of Radiotherapy in the Management of Rectal Carcinoma

Management of locally advanced rectal cancer has evolved over time from surgical resection alone to multimodality therapy with preoperative radiation, chemotherapy, and total mesorectal excision resulting in excellent local control rates. Refinements in neoadjuvant therapies and their sequencing have improved pathologic complete response rates such that consideration of selective radiation and nonoperative management are now active clinical trial questions. Advances in radiation treatment planning and delivery techniques may allow for further reduction in acute treatment-related toxicity in select patient populations. Collectively, therapeutic strategies remain focused on improving outcomes for patients with higher-risk disease and reducing the morbidity of treatment.

Adjuvant Radiotherapy Use by US Radiation Oncologists After Radical Cystectomy for Muscle-invasive Bladder Cancer

AIMS

Historic trials suggested significant toxicity with adjuvant radiotherapy (ART) after radical cystectomy for muscle-invasive bladder cancer (MIBC). However, recent trials have found improved locoregional control and the 2016 National Comprehensive Cancer Network (NCCN) guidelines recommend ART consideration for select patients at high risk of local recurrence. ART practice patterns among US radiation oncologists are unknown and we carried out a survey to explore current trends.

MATERIALS AND METHODS

We conducted a survey of US radiation oncologists regarding the management of patients with cT2-3N0M0 transitional cell MIBC. Responses were reported using descriptive statistics. Chi-square and univariate logistic regression of clinical and demographic covariates were conducted, followed by multivariable logistic regression analysis to identify factors predicting for ART use.

RESULTS

In total, 277 radiation oncologists completed our survey. Nearly half (46%) have used ART for MIBC at least once in the past. In ART users, indications for ART include gross residual disease (93%), positive margins (92%), pathological nodal involvement (64%), pT3 or T4 disease (46%), lymphovascular invasion (16%) and high-grade disease (13%). On univariate logistic regression, ART use was associated with the number of years in practice (P=0.04), pre-cystectomy radiation oncology consultation (P=0.004), primarily treating MIBC patients fit for cystectomy (P=0.01) and intensity-modulated radiotherapy use (P=0.01). On multivariable logistic regression analysis, routine pre-cystectomy radiation oncology consultation (odds ratio 1.91, 95% confidence interval 1.04-3.51; P=0.04) and intensity-modulated radiotherapy use (odds ratio 2.77, 95% confidence interval 1.48-5.22; P=0.002) remained associated with ART use.

CONCLUSIONS

ART use is controversial in bladder cancer, yet unexpectedly has commonly been used among US radiation oncologists treating patients with MIBC after radical cystectomy. NRG-GU001 was a randomised trial in the US randomizing patients with high-risk pathological findings for observation or ART after cystectomy. However, due to poor accrual it recently closed and thus it will be up to other international trials to clarify the role of ART and identify patients benefiting form this adjuvant therapy.

An update on the multimodality of localized rectal cancer

New strategies have reduced the local recurrence (LR) rate and extended the duration of overall survival (OS) in patients with localized rectal cancer (RC) in recent decades. The mainstay of curative treatment remains radical surgery; however, downsizing the tumor by neo-adjuvant chemo-radiotherapy and adjuvant cytotoxic therapy for systemic disease has shown significant additional benefit. The standardization of total mesorectal excision (TME), radiation treatment (RT) dose and fractionation, and optimal timing and sequencing of treatment modalities with the use of prolonged administration of fluoropyrimidine concurrent with RT have significantly decreased the rates of LR in locally advanced rectal cancer (LARC) patients. This review focuses on the optimization of multi-modality therapies in patients with localized RC.

Long Term Outcomes of Preoperative versus Postoperative Concurrent Chemoradiation for Locally Advanced Rectal Cancer: Experience from Ramathibodi Medical School in Thailand

OBJECTIVES

The study analyzed and compared the long term outcome in locally advanced rectal cancer treated with preoperative and postoperative concurrent chemoradiation (CCRT).

MATERIALS AND METHODS

A retrospective review of 105 patients with stage T3-T4 or regional lymph node positive adenocarcinoma of rectum treated with preoperative or postoperative CCRT at Ramathibodi Hospital during 2005 to 2010 was performed. The results of treatment were reported with 5-year overall survival (OS), 5- year locoregional recurrence free survival (LRFS), and toxicity according to preoperative versus postoperative concurrent chemoradiation (CCRT) groups.

RESULTS

Among 105 patients, 34 (32%) were treated with preoperative CCRT and 71 (68%) with postoperative CCRT. At the median follow-up time of 50.5 months (range 2-114 months), five-year OS and LRFS of all patients were 87% and 91.6%, respectively. The study found no difference in 5-year OS (81.7% vs 89.2 %) or LRFS (83.4% vs 95.1%) between preoperative versus postoperative CCRT. Seven cases of loco-regional recurrence were diagnosed, 4 (11.8%) after preoperative CCRT and 3 (4.2%) after postoperative CCRT. The recurrent sites were anastomosis in all patients. There was no significant factor associated with outcome after univariate and multivariate testing. Grade 3 or 4 acute and late complications were low in both preoperative and postoperative CCRT groups.

CONCLUSIONS

Locally advanced rectum cancer patients experience good results with surgery and adjuvant concurrent chemoradiation.

The Impact of Preoperative Radiation Therapy on Locoregional Recurrence in Patients with Stage IV Rectal Cancer Treated with Definitive Surgical Resection and Contemporary Chemotherapy

PURPOSE

Definitive resection of primary rectal cancers is frequently incorporated, with or without preoperative radiotherapy and perioperative chemotherapy, in the management of selected patients with metastatic rectal adenocarcinoma. This study reviews the impact of preoperative radiotherapy and perioperative chemotherapy on locoregional recurrence and overall survival in these patients.

METHODS AND MATERIALS

This retrospective study with an Institutional Review Board (IRB) waiver included 109 patients with metastatic rectal adenocarcinoma who underwent definitive primary resection between 1998 and 2011. In addition to resection, 64 patients were treated with preoperative radiotherapy and perioperative chemotherapy and 45 patients were treated with perioperative chemotherapy alone. Radiotherapy dose was typically 50.4 Gy. Baseline variables were compared using chi-square and unpaired t tests. Overall survival was calculated using Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox proportional hazards regression.

RESULTS

There were no significant baseline differences between the two groups. There was no significant difference in locoregional recurrence (10.9 vs. 11.1%; p = 0.90) or overall survival (34.5 vs. 34.8 months; p = 0.89) for patients treated with preoperative radiotherapy compared to those treated with perioperative chemotherapy alone, respectively. Patients who underwent radiotherapy were less likely to have a positive margin (10.9 vs. 20.0%; p = 0.19), lymphovascular invasion (32.8 vs. 53.3%; p = 0.03), and pathologic stage N2 disease (25.0 vs. 42.2%; p = 0.02). Grade 2 postoperative complications were more common in the preoperative radiotherapy group (32.8 vs. 15.6%; p = 0.04). Multivariate analysis demonstrated that patients with poorly differentiated tumors (HR 2.19; p = 0.009) and those that did not undergo liver-directed therapy (HR 2.20; p = 0.005) had inferior survival.

CONCLUSIONS

Locoregional recurrence is modest in patients with metastatic rectal adenocarcinoma receiving definitive primary resection, irrespective of the use of radiotherapy. Preoperative radiotherapy may enhance pathologic downstaging at the expense of increased grade 2 postoperative complications. Its use should be reserved for patients at high risk for locoregional recurrence.

Patterns of Colorectal Cancer Care in the United States: 1990-2010

BACKGROUND

Colorectal cancer (CRC) mortality has declined in the United States, in part because of advances in treatment. Few studies have evaluated the adoption of therapies and temporal changes in patterns of care.

METHODS

Patients age 20 years and older diagnosed with stages II/III CRC were randomly sampled from the population-based Surveillance, Epidemiology, and End Results (SEER) program in 1990-1991, 1995, 2000, 2005, and 2010 (n = 7057). Therapy was obtained from medical records and physician verification. We described the receipt of chemotherapy and radiation therapy. Log-binomial regression was used to examine factors associated with therapy. All statistical tests were two-sided.

RESULTS

Chemotherapy receipt among colon cancer patients increased from 1990 (stage II: 22.5%; stage III: 56.3%) to 2005 (stage II: 32.1%; stage III: 72.4%) and declined slightly in 2010 (stage II: 29.3%; stage III: 66.4%). Stage III colon cancer patients who were older (vs <55 years, 75-79 years: risk ratio [RR] 0.81, 95% confidence interval [CI] = 0.71 to 0.91; ≥80 years: RR = 0.37, 95% CI = 0.28 to 0.47) or had a comorbidity score of 2 or higher (vs 0, RR = 0.56, 95% CI = 0.35 to 0.87) received chemotherapy less often. Receipt of radiation therapy by rectal cancer patients increased across all years from 45.5% to 66.1%. Increasing age (vs <55 years, 75-79 years: RR = 0.59, 95% CI = 0.47 to 0.74; ≥80 years: RR = 0.33, 95% CI = 0.25 to 0.45) was associated with lower chemoradiation use among stage II/III rectal cancer patients.

CONCLUSION

Our findings demonstrate increased adoption of chemotherapy and radiation therapy for colon and rectal cancer patients and differences in therapy by age, comorbidity, and diagnosis year. Increased receipt of these therapies in the community may further reduce CRC mortality.

Review on adjuvant chemotherapy for rectal cancer - why do treatment guidelines differ so much?

BACKGROUND

The use of postoperative adjuvant chemotherapy is controversial for rectal adenocarcinoma. Both international and national guidelines display a great span varying from recommending no adjuvant chemotherapy at all, over single drug 5-fluororuacil (5-FU), to combinations of 5-FU/oxaliplatin.

METHODS

A review of the literature was made identifying 24 randomized controlled trials on adjuvant treatment of rectal cancer based on about 10 000 patients. The trials were subdivided into a number of clinically relevant subgroups.

RESULTS

As regards patients treated with preoperative (chemo) radiotherapy, four randomized studies were found where use of adjuvant chemotherapy showed no benefit in survival. Three trials were found in which a subset of patients received preoperative (chemo) radiotherapy. Two of these trials showed a statistically significant benefit of adjuvant chemotherapy. Twenty trials were identified in which the patients did not receive preoperative (chemo) radiotherapy, including five Asian studies in which a statistically significant benefit from adjuvant chemotherapy was reported.

CONCLUSIONS

Most of the data found did not support the use of postoperative adjuvant chemotherapy for patients already treated with preoperative (chemo) radiotherapy. For patients not treated preoperatively, several studies support the use of single agent 5-FU chemotherapy. Treatment guidelines seem to differ according to if preoperative chemoradiation is considered of importance for use of adjuvant chemotherapy and if adjuvant colon cancer studies are considered transferrable to rectal cancer patients regardless of the molecular differences.

Neoadjuvant chemotherapy without radiotherapy for locally advanced rectal cancer

ABSTRACT 

Chemoradiotherapy or short-course radiotherapy followed by surgery is a standard treatment for locally advanced rectal cancer. This multimodality strategy has reduced the risk of local recurrence but failed to improve survival. Moreover, mid- and long-term side effects of radiotherapy have been reported. Alternative strategies have been investigated in an attempt to minimize treatment-related toxicities and improve outcome. Neoadjuvant chemotherapy without radiotherapy is an attractive therapeutic option that yields theoretical advantages. Moreover, if carefully selected, patients may be spared the effects of radiotherapy without compromising the oncology outcome. The authors review the available evidence on neoadjuvant chemotherapy without radiotherapy in locally advanced rectal cancer and try to anticipate potential algorithms of treatment selection to implement in clinical practice in the future.

Current options in chemoradiotherapy for rectal cancer

SUMMARY The management of rectal adenocarcinoma and the role of radiation in the adjuvant and neoadjuvant setting is evolving. Randomized clinical trials established the role of neoadjuvant chemoradiation (CRT), primarily in patients with T3/T4 and/or node-positive tumor presentations. Clinical trials comparing short-course radiotherapy with long-course CRT have been undertaken, and data supporting treatment with definitive CRT-reserving surgery for salvage is emerging. Clinical research to enhance the efficacy of the 5-fluorouracil-based CRT platform is being investigated, incorporating a variety of chemotherapeutics and targeted agents.

ACR appropriateness criteria® resectable rectal cancer

The management of resectable rectal cancer continues to be guided by clinical trials and advances in technique. Although surgical advances including total mesorectal excision continue to decrease rates of local recurrence, the management of locally advanced disease (T3-T4 or N+) benefits from a multimodality approach including neoadjuvant concomitant chemotherapy and radiation. Circumferential resection margin, which can be determined preoperatively via MRI, is prognostic. Toxicity associated with radiation therapy is decreased by placing the patient in the prone position on a belly board, however for patients who cannot tolerate prone positioning, IMRT decreases the volume of normal tissue irradiated. The use of IMRT requires knowledge of the patterns of spreads and anatomy. Clinical trials demonstrate high variability in target delineation without specific guidance demonstrating the need for peer review and the use of a consensus atlas. Concomitant with radiation, fluorouracil based chemotherapy remains the standard, and although toxicity is decreased with continuous infusion fluorouracil, oral capecitabine is non-inferior to the continuous infusion regimen. Additional chemotherapeutic agents, including oxaliplatin, continue to be investigated, however currently should only be utilized on clinical trials as increased toxicity and no definitive benefit has been demonstrated in clinical trials. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Do all locally advanced rectal cancers require radiation? A review of literature in the modern era

Potentially curable rectal cancer is primarily treated with surgical resection. Adjuvant or neoadjuvant radiotherapy is often utilized for patients deemed to be at unacceptable risk for local recurrence. The purpose of this article is to review the pertinent literature and elucidate the role of radiotherapy in patients with an intermediate risk of local recurrence. The addition of chemoradiotherapy is recommended in the majority of patients with transmural or node positive rectal cancer. However, some patients with favorable characteristics may have only a small incremental benefit from the addition of radiotherapy. The decision to treat or not to treat should take into consideration the patient and physician tolerance of risk of recurrence and risk of treatment related toxicity. The primary factors identified for determining low risk patients are circumferential radial margin (CRM), location within the rectum, and nodal status. Patients at lowest risk have widely negative CRM (>2mm), proximal lesions (>10cm from the anal verge), and no nodal disease. Patients with all three low risk factors have an absolute reduction in local recurrence that is <5% and may be eligible to forego radiotherapy. Additional factors identified which may impact local recurrence risk are elevated serum CEA level, lymphovascular space invasion, pathologic grade, and extramural space invasion.

The therapeutic and adverse effects of modified radiation fields for patients with rectal cancer

PURPOSE

To compare the therapeutic effect and complications of modified radiation fields (MRFs) with those of conventional pelvic radiation fields (CPRFs) for rectal cancer.

METHODS AND MATERIALS

From December 1996 to October 2009, a total of 160 patients with rectal carcinoma who received total mesorectal excision and postoperative radiotherapy were examined. Ninety-four patients were in the CPRFs group, and 66 were in the MRFs group. The dose was 50 Gy per 25 fractions in the initial plan.

RESULTS

The treatment volume and the volume of small bowel that received more than 15 Gy of the MRFs was smaller than that of the CPRFs (P < .001). The rates of local recurrence, overall survival, and disease-free survival were not statistically significant between the MRFs and CPRFs groups (P > .05). There was a statistical difference (P < .05) in the incidence of acute toxicity, which included serious complications in the lower digestive tract (grade ≥3). The completion rate for the initial radiotherapy plan was higher in the MRFs group than in the CPRFs group (P = .027).

CONCLUSIONS

Compared with CPRFs, MRFs manifested a lower incidence of complications and the same therapeutic effects. This finding will facilitate the clinical application of MRFs for patients with rectal cancer.