Nonoperative management of rectal cancer with complete clinical response after neoadjuvant therapy. Ann Surg. 2012;256:965-972. [PMID: 23154394 DOI: 10.1097/sla.0b013e3182759f1c]

Decision-Making Strategy for Rectal Cancer Management Using Radiation Therapy for Elderly or Comorbid Patients

Rectal cancer predominantly affects patients older than 70 years, with peak incidence at age 80 to 85 years. However, the standard treatment paradigm for rectal cancer oftentimes cannot be feasibly applied to these patients owing to frailty or comorbid conditions. There are currently little information and no treatment guidelines to help direct therapy for patients who are elderly and/or have significant comorbidities, because most are not included or specifically studied in clinical trials. More recently various alternative treatment options have been brought to light that may potentially be utilized in this group of patients. This critical review examines the available literature on alternative therapies for rectal cancer and proposes a treatment algorithm to help guide clinicians in treatment decision making for elderly and comorbid patients.

Watch-and-Wait as a Therapeutic Strategy in Rectal Cancer

Purpose of Review

Pathological complete response is seen in approximately one fifth of rectal cancer patients following neoadjuvant chemoradiation. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who develop a clinical complete response. We review the watch-and-wait strategy and focus on all aspects of this hot topic, including who should be considered for this approach, how should we identify treatment response and what are the expected outcomes.

Recent Findings

The major challenges in interpreting the data on watch-and-wait are the significant heterogeneity of patients selected for this approach and of methods employed to identify them. The evidence available comes mostly from retrospective cohort studies, but has shown good oncological outcomes, including the rate of successful salvage surgery, locoregional control and overall survival.

Summary

There is currently not enough and not robust enough evidence to support watch-and-wait as a standard approach, outside a clinical trial, for patients achieving clinical complete response following neoadjuvant chemoradiation. Furthermore, there is a lack of data on long-term outcomes. However, the results we have so far are promising, and there is therefore an urgent need for randomised control studies such as the TRIGGER trial to confirm the safety of this strategy.

Wait-and-see treatment strategies for rectal cancer patients with clinical complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

Wait-and-see treatment strategies may benefit rectal cancer patients who achieve a clinical complete response (cCR) after neoadjuvant chemoradiotherapy (NCRT). In this study, we analyzed data from 9 eligible trials to compare the oncologic outcomes of 251 rectal cancer patients achieving a cCR through nonsurgical management approaches with the outcomes of 344 patients achieving a pathologic complete response (pCR) through radical surgery. The two patient groups did not differ in distant metastasis rates or disease-free and overall survival, but the nonsurgical group had a higher risk of 1, 2, 3, and 5-year local recurrence. Hence, we concluded that for rectal cancer patients achieving a cCR after NCRT, a wait-and-see strategy with strict selection criteria, an appropriate follow-up schedule, and salvage treatments achieved outcomes at least as good as radical surgery. Long-term randomized and controlled trials with more uniform inclusion criteria and standardized follow-up schedules will help clarify the risks and benefits of wait-and-see treatment strategies for these patients.

Long-term outcomes in patients with ypT0 rectal cancer after neoadjuvant chemoradiotherapy and curative resection

Objective

For patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy (NCRT), significant pathological response of the primary tumor has been proposed to identify candidates for organ preservation. However, this does not address metastatic lymph nodes in the mesorectum. The aim of this study was to assess the incidence of lymph node metastases in ypT0 patients treated with NCRT and curative resection and to explore risk factors associated with survival.

Methods

This was a retrospective study of patients with ypT0 rectal cancer after NCRT and curative resection at a tertiary care center in China from 2005 to 2014.

Results

A total of 60 (18.6%) patients who underwent surgery after NCRT and achieved ypT0 were enrolled in this study; one patient was excluded owing to lack of follow-up. Of these 59 patients, lymph node metastases were found in the mesorectum (ypT0N+) in eight (13.6%) patients. After a median follow-up of 52 months, 5-year recurrence-free survival (82.7% vs. 62.5%, P=0.014) and overall survival (OS) (90.9% vs. 70.0%, P=0.032) were much higher in ypN0 than ypN+ patients. Multivariate analyses showed that ypN+ status (P=0.009) and perioperative blood transfusion (BT) (P=0.001) were significantly independent risk factors associated with recurrence; however, no factor was correlated with 5-year OS.

Conclusions

Patients with ypT0N0 rectal cancer can achieve excellent long-term outcomes; however, positive lymph nodes or tumor deposits can still be found in 13.6% of ypT0 patients. Nodal positivity in the mesorectum and perioperative BT are independent risk factors for recurrence.

Controversial issues in radiotherapy for rectal cancer: a systematic review

The role of radiotherapy (RT) as an adjuvant to surgical options in the treatment of locally advanced rectal cancer has been established as it reduces local recurrence when combined with surgical resection and enhances survival when used in multidisciplinary treatment. However, many issues need to be addressed; some of these can render RT unnecessary, whereas others can reveal a new role of RT in rectal cancer. This review will discuss not only the basic role of RT but also the associated but controversial issues in detail in an attempt to find answers and determine future directions for the next decade.

Timing Is Everything: What Is the Optimal Duration After Chemoradiation for Surgery for Rectal Cancer?

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology , to patients seen in their own clinical practice. A 47-year-old woman was referred for management of a newly diagnosed rectal cancer. She presented with a 2-month history of rectal bleeding and change in bowel habits. She underwent a colonoscopy that demonstrated a 5-cm fungating, friable, and partially obstructing mass in the distal rectum, approximately 5 cm from the anal verge. The tumor was palpable on digital rectal examination on the anterior wall of rectum. The biopsy demonstrated a moderately differentiated invasive adenocarcinoma, microsatellite stable. A staging work-up, including a computed tomography scan of the chest, abdomen, and pelvis, demonstrated rectal wall thickening in the midrectum and small lymph nodes in the left perirectal fat. There was a nonspecific 3-mm right lower lobe pulmonary nodule. Rectal magnetic resonance imaging demonstrated a 3-cm mass arising from mid-distal rectum with minimal extension beyond muscularis propria into the mesorectal fat, but without invasion of mesorectal fascia ( Fig 1 ). There were at least three small mesorectal lymph nodes present; the largest rounded node measured up to 5 mm, and no additional pelvic lymphadenopathy was identified. Her carcinoembryonic antigen was 1.1, and all other laboratory studies were within normal limits. She was seen in the Colorectal Multidisciplinary Conference for a discussion of her treatment options.

Organ-Preserving Strategies for the Management of Near-Complete Responses in Rectal Cancer after Neoadjuvant Chemoradiation

In recent years, organ preservation has been considered a feasible alternative to total mesorectal excision for patients with locally advanced rectal cancer with a clinical complete response to neoadjuvant therapy. However, the degree of tumor response to neoadjuvant therapy is variable. A fraction of the patients who did not achieve a complete response had grossly visible tumors. These patients, with clearly incomplete clinical response, need a total mesorectal excision. In addition, some patients with a significant tumor response still have some abnormalities in the bowel wall, such as superficial ulceration or tissue nodularity, which, while not conclusive for the presence of a tumor, are indicative of the possibility of a residual tumor in the bowel wall or in mesorectal lymph nodes. The management of patients with a so-called near-complete clinical response to neoadjuvant therapy is controversial. In this article, we will review the clinical and radiological criteria that define a clinical response to neoadjuvant therapy, possible treatment strategies, and follow-up protocols. We will also discuss patient and tumor characteristics that in our opinion can be useful in selecting the most appropriate treatment alternative. Although organ preservation and quality of life are important, the primary goal of treatment for these patients should be local tumor control and long-term survival.

Density of CD8+ lymphocytes in biopsy samples combined with the circulating lymphocyte ratio predicts pathologic complete response to chemoradiotherapy for rectal cancer

Objectives

The systemic status and local immune status, as determined by the neutrophil–lymphocyte ratio (NLR) or the lymphocyte ratio (LYMR) and tumor-infiltrating lymphocyte (TIL) count, respectively, have been suggested as predictors of the tumor response to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer, although the utility of these measures remains controversial. We aimed to investigate the values of the LYMR, NLR and TIL count and their combinations (TIL–LYMR/TIL–NLR) in predicting pathologic complete response (pCR) after nCRT.

Patients and methods

Pretreatment biopsy samples and data from the blood tests of 92 patients with rectal cancer who underwent curative resection after nCRT were retrospectively obtained. CD8+ TILs were immunostained using an antibody against CD8. The density of CD8+ TILs was recorded as the number of CD8+ T cells per square millimeter, and the results were classified as either “high” or “low”. The LYMR and NLR were calculated using pretreatment blood test data and categorized into either “high” or “low” groups. TIL–LYMR was graded as “low,” “mid” or “high” when neither, one or both the CD8+ TIL count and LYMR were “high,” respectively. TIL–NLR was graded similarly. The associations between TILs and LYMR, NLR and their combinations (TIL–LYMR/TIL–NLR) were evaluated.

Results

pCR was significantly associated with a high LYMR, a low NLR and increased chemotherapy cycles (P=0.039, P=0.043 and P=0.015, respectively), but not with the CD8+ TIL count or carcinoembryonic antigen (CEA) level (P=0.100 and P=0.590, respectively). Additionally, 40% of patients with high LYMR and 40.7% with low NLR achieved pCR, whereas only 19.7% with low LYMR and 20.3% with high NLR did so. When the combinations were assessed, TIL–LYMR showed a positive correlation with pCR (P=0.038), while no association between TIL–NLR and pCR was found (P=0.916). In multivariate analysis, TIL–LYMR remained an independent predictor of pCR (odds ratio [OR]=1.833, 95% confidence interval [CI]=1.069–3.142, P=0.028).

Conclusion

High LYMR, low NLR and high TIL–LYMR at baseline are predictive of pCR to nCRT for patients with rectal cancer. These parameters may help identify pCR patients and provide additional information for therapeutic decision-making.

Organ Preservation in Rectal Cancer After Chemoradiation: Should We Extend the Observation Period in Patients with a Clinical Near-Complete Response?

BACKGROUND

To assess whether extending the observation period in patients with a near clinical complete response (near cCR) after chemoradiation (CRT) leads to an impaired oncological outcome.

METHODS

Patients who had a clinical complete response (cCR) 8-10 weeks after CRT restaging with magnetic resonance imaging and endoscopy were offered a watch-and-wait strategy (W&W1), while patients with a near cCR were offered to undergo local excision or a second restaging 6-12 weeks later. Patients who achieved a cCR at the second restaging were also offered a watch-and-wait strategy (W&W2).

RESULTS

Overall, 102 patients with a cCR at the first restaging immediately entered the W&W1, while the remaining 68 patients had a near cCR: 19 patients underwent transanal endoscopic microsurgery and 49 patients opted for a second restaging. Additionally, 44/49 (90%) patients showed a cCR at the second restaging and entered the W&W2. Patients in the W&W1 group had a 2-year local regrowth-free rate (LRFR) of 84% and 2-year overall survival (OS) of 99%, while patients in the W&W2 group had a 2-year LRFR of 73% and OS of 98% (p > 0.05). Multivariable Cox regression analyses showed that late inclusion was not a significant predictive factor for higher risk of LR or lower non-regrowth disease-free survival.

CONCLUSIONS

Overall, 90% of patients with a near cCR 8-10 weeks after CRT will proceed to a cCR 6-12 weeks later; therefore, it seems logical to extend the observation period rather than to proceed to surgery. Although there is a non-significant increase in local regrowth rate in these patients, it does not seem to impact the oncological outcome.

Current issues of preoperative radio(chemo)therapy and its future evolution in locally advanced rectal cancer

Neoadjuvant therapies are effective for local control and tumor downstaging. Up to date, preoperative long-course chemoradiotherapy and short-course radiotherapy are the two primary guideline-recommended neoadjuvant therapies for locally advanced rectal cancer patients. However, clinicians throughout the world are trying their best to further optimize the regimens and concepts of neoadjuvants. Hence, there is an urgent need to summarize evidence regarding indications of neaoadjuvant therapies and relative merits of current standard regimens. In addition, we also reviewed the optimized regimens mainly based on short-course radiotherapy with delayed surgery, consolidation chemotherapy, induction chemotherapy, chemotherapy alone without radiation and concepts in terms of organ preservation and personalized treatments to further explore the future evolution of neoadjuvant therapies in rectal cancer.

Clinical Significance of the Endoscopic Finding in Predicting Complete Tumor Response to Preoperative Chemoradiation Therapy in Rectal Cancer

BACKGROUND

There are reports that suggest conservative treatment when a tumor shows clinically complete response (CR) after preoperative chemoradiotherapy in rectal cancer. The aim of this study is to investigate the association between endoscopic complete response (E-CR) and pathologic CR (pCR) and to determine the sensitivity and specificity of E-CR and its clinical utility after preoperative chemoradiotherapy in rectal cancer.

METHODS

We analyzed prospectively collected data of patients with middle and lower rectal cancers who underwent preoperative chemoradiotherapy, between January 2010 and January 2015.

RESULTS

Nineteen patients (17.9 %) showed E-CR, and 87 patients showed E-non CR. Twenty-three patients (21.7 %) were confirmed to have pCR. E-CR was closely associated with pCR (p < 0.001). E-CR reflected pCR with an accuracy of 88.7 %, sensitivity of 65.2 %, specificity of 95.2 %, PPV of 78.9 %, NPV of 90.8 %, and a p value of <0.001.

CONCLUSIONS

E-CR after preoperative chemoradiotherapy in rectal cancer is significantly associated with pCR. However, a wait and see policy should be performed carefully with current endoscopic prediction for pCR to avoid inadequate treatment in patients who show E-CR after preoperative chemoradiotherapy.

Dose Escalation Using Contact X-ray Brachytherapy After External Beam Radiotherapy as Nonsurgical Treatment Option for Rectal Cancer: Outcomes From a Single-Center Experience

PURPOSE

To review the outcomes of rectal cancer patients treated with a nonsurgical approach using contact x-ray brachytherapy (CXB) when suspicious residual disease (≤3 cm) was present after external beam chemoradiation therapy/radiation therapy (EBCRT/EBRT).

METHODS AND MATERIALS

Outcome data for rectal cancer patients referred to our institution from 2003 to 2012 were retrieved from an institutional database. These patients were referred after initial local multidisciplinary team discussion because they were not suitable for, or had refused, surgery. All selected patients received a CXB boost after EBCRT/EBRT. Most patients received a total of 90 Gy of CXB delivered in 3 fractions over 4 weeks.

RESULTS

The median follow-up period was 2.5 years (range 1.2-8.3). Of 345 consecutive patients with rectal cancer referred to us, 83 with suspicious residual disease (≤3 cm) after EBCRT/EBRT were identified for a CXB boost. Their median age was 72 years (range 36-87), and 58 (69.9%) were men. The initial tumor stages were cT2 (n = 28) and cT3 (n = 55), and 54.2% were node positive. A clinical complete response (cCR) was achieved in 53 patients (63.8%) after the CXB boost that followed EBCRT/EBRT. Of these 53 patients, 7 (13.2%) developed a relapse after achieving a cCR, and the 6 patients (11.6%) with nonmetastatic regrowth underwent salvage surgery (100%). At the end of the study period, 69 of 83 patients (83.1%) were cancer free.

CONCLUSIONS

Our data suggest that a CXB boost for selected patients with suspicious residual disease (≤3 cm) after EBCRT/EBRT can be offered as an alternative to radical surgery. In our series, patients with a sustained cCR had a low rate of local regrowth, and those with nonmetastatic regrowth could be salvaged successfully. This approach could provide an alternative treatment option for elderly or comorbid patients who are not suitable for surgery and those with rectal cancer who wish to avoid surgery.

Understanding and Resetting Radiation Sensitivity in Rectal Cancer

OBJECTIVE

The aim of the study was to explore specific microRNAs (miRs) in rectal cancer that would predict response to radiation and identify target pathways that may be exploited for neoadjuvant therapies.

SUMMARY BACKGROUND DATA

Chemoradiotherapy (CRT) response is a predictor of survival in rectal cancer. Studies have demonstrated changes in RNA expression correlate with chemoradiation sensitivity across cancers.

METHODS

Forty-five rectal cancer patients, partial responders (PR = 18), nonresponders (NR = 13), and complete responders (CR = 14) to CRT, as defined by a tumor regression score, were examined. miRs differentially expressed, using NanoString microArray profiling, were validated with qPCR. We quantified 1 miR and its downstream targets in patient samples. Chemosensitivity was measured in HCT-116, a human colorectal carcinoma cell line, using inhibitors of SHP2 and RAF.

RESULTS

miR-451a, 502-5p, 223-3p, and 1246 were the most upregulated miRs (>1.5-fold change) in a NanoString profiling miR panel. qPCR revealed a decrease in expression of miR-451a in NRs. EMSY and CAB39, both downstream targets of miR-451a and involved in carcinogenesis (shown in TCGA) were increased in NRs (qPCR). Both targets are associated with worse survival in colorectal cancer. Inhibition of miR-451a in HCT-116 cells significantly decreased cell proliferation with treatment of SHP2 and RAF inhibitors.

CONCLUSIONS

An integrated analysis of rectal cancer miRs may yield biomarkers of radioresistance and offer treatment targets for resensitization.

A rectal cancer feasibility study with an embedded phase III trial design assessing magnetic resonance tumour regression grade (mrTRG) as a novel biomarker to stratify management by good and poor response to chemoradiotherapy (TRIGGER): study protocol for a randomised controlled trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) for MRI-defined, locally advanced rectal cancer is primarily intended to reduce local recurrence rates by downstaging tumours, enabling an improved likelihood of curative resection. However, in a subset of patients complete tumour regression occurs implying that no viable tumour is present within the surgical specimen. This raises the possibility that surgery may have been avoided. It is also recognised that response to CRT is a key determinant of prognosis. Recent radiological advances enable this response to be assessed pre-operatively using the MRI tumour regression grade (mrTRG). Potentially, this allows modification of the baseline MRI-derived treatment strategy. Hence, in a 'good' mrTRG responder, with little or no evidence of tumour, surgery may be deferred. Conversely, a 'poor response' identifies an adverse prognostic group which may benefit from additional pre-operative therapy.

METHODS/DESIGN

TRIGGER is a multicentre, open, interventional, randomised control feasibility study with an embedded phase III design. Patients with MRI-defined, locally advanced rectal adenocarcinoma deemed to require CRT will be eligible for recruitment. During CRT, patients will be randomised (1:2) between conventional management, according to baseline MRI, versus mrTRG-directed management. The primary endpoint of the feasibility phase is to assess the rate of patient recruitment and randomisation. Secondary endpoints include the rate of unit recruitment, acute drug toxicity, reproducibility of mrTRG reporting, surgical morbidity, pathological circumferential resection margin involvement, pathology regression grade, residual tumour cell density and surgical/specimen quality rates. The phase III trial will focus on long-term safety, regrowth rates, oncological survival analysis, quality of life and health economics analysis.

DISCUSSION

The TRIGGER trial aims to determine whether patients with locally advanced rectal cancer can be recruited and subsequently randomised into a control trial that offers MRI-directed patient management according to radiological response to CRT (mrTRG). The feasibility study will inform a phase III trial design investigating stratified treatment of good and poor responders according to 3-year disease-free survival, colostomy-free survival as well as an increase in cases managed without a major resection.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02704520 . Registered on 5 February 2016.

Rectal sparing approach after preoperative radio- and/or chemotherapy (RESARCH) in patients with rectal cancer: a multicentre observational study

BACKGROUND

Rectum-sparing approaches appear to be appropriate in rectal cancer patients with a major (mCR) or complete clinical response (cCR) after neoadjuvant therapy. The aim of the present study is to evaluate the effectiveness of rectum-sparing approaches at 2 years after the completion of neoadjuvant treatment.

STUDY DESIGN

Patients with rectal adenocarcinoma eligible to receive neoadjuvant therapy will be prospectively enrolled. Patients will be restaged 7-8 weeks after the completion of neoadjuvant therapy and those with mCR (defined as absence of mass, small mucosal irregularity no more than 2 cm in diameter at endoscopy and no metastatic nodes at MRI) or cCR will be enrolled in the trial. Patients with mCR will undergo local excision, while patients with cCR will either undergo local excision or watch and wait policy. The main end point of the study is to determine the percentage of rectum preservation at 2 years in the enrolled patients.

CONCLUSION

This protocol is the first prospective trial that investigates the role of both local excision and watch and wait approaches in patients treated with neoadjuvant therapy for rectal cancer. The trial is registered at clinicaltrials.gov (NCT02710812).

Predictive clinical model of tumor response after chemoradiation in rectal cancer

Survival improvement in rectal cancer treated with neoadjuvant chemoradiotherapy (nCRT) is achieved only if pathological response occurs. Mandard tumor regression grade (TRG) proved to be a valid system to measure nCRT response. The ability to predict tumor response before treatment may significantly have impact the selection of patients for nCRT in rectal cancer. The aim is to identify potential predictive pretreatment factors for Mandard response and build a clinical predictive model design. 167 patients with locally advanced rectal cancer were treated with nCRT and curative surgery. Blood cell counts in peripheral blood were analyzed. Pretreatment biopsies expression of cyclin D1, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and protein 21 were assessed. A total of 61 single nucleotide polymorphisms were characterized using the Sequenom platform through multiplex amplification followed by mass-spectometric product separation. Surgical specimens were classified according to Mandard TRG. The patients were divided as: "good responders" (Mandard TRG1-2) and "poor responders" (Mandard TGR3-5). We examined predictive factors for Mandard response and performed statistical analysis. In univariate analysis, distance from anal verge, neutrophil lymphocyte ratio (NLR), cyclin D1, VEGF, EGFR, protein 21 and rs1810871 interleukin 10 (IL10) gene polymorphism are the pretreatment variables with predictive value for Mandard response. In multivariable analysis, NLR, cyclin D1, protein 21 and rs1800871 in IL10 gene maintain predictive value, allowing a clinical model design.

CONCLUSION

It seems possible to use pretreatment expression of blood and tissue biomarkers, and build a model of tumor response prediction to neoadjuvant chemoradiation in rectal cancer.

Bowel Dysfunction After Low Anterior Resection With Neoadjuvant Chemoradiotherapy or Chemotherapy Alone for Rectal Cancer: A Cross-Sectional Study from China

BACKGROUND

Neoadjuvant therapy plays a vital role in the treatment of locally advanced rectal cancer but impairs bowel function after restorative surgery. Optimal decision making requires adequate information of functional outcomes.

OBJECTIVE

This study aimed to assess postoperative bowel function and to identify predictors for severe dysfunction.

DESIGN

The study included a cross-sectional cohort and retrospective assessments of pelvic anatomic features.

SETTINGS

The study was conducted at a tertiary GI hospital in China.

PATIENTS

Included patients underwent neoadjuvant chemoradiotherapy or chemotherapy without radiation and curative low anterior resection for rectal cancer between 2012 and 2014.

MAIN OUTCOME MEASURES

Bowel function was assessed using the validated low anterior resection syndrome score. The thicknesses of the rectal wall, obturator internus, and levator ani were measured by preoperative MRI.

RESULTS

A total of 151 eligible patients were identified, and 142 patients (94.0%) participated after a median of 19 months from surgery. Bowel dysfunction was observed in 71.1% (101/142) of patients, with 44.4% (63/142) reporting severe dysfunction. Symptoms of urgency and clustering were found to be major disturbances. Regression analysis identified preoperative long-course radiotherapy (p < 0.001) and a lower-third tumor (p = 0.002) independently associated with severe bowel dysfunction. Irradiated patients with a lower-third tumor (OR = 14.06; p < 0.001) or thickening of the rectal wall (OR = 11.09; p < 0.001) had a markedly increased risk of developing severe dysfunction.

LIMITATIONS

The study was based on a limited cohort of patients and moderate follow-up after the primary surgery.

CONCLUSIONS

Bowel function deteriorates frequently after low anterior resection for rectal cancer. Severe bowel dysfunction is significantly associated with preoperative long-course radiotherapy and a lower-third tumor, and the thickening of rectal wall after radiation is a strong predictor. Treatment decisions and patient consent should be implemented with raising awareness of bowel symptom burdens. See Video Abstract at http://links.lww.com/DCR/A317.

Molecular profiling of locally-advanced rectal adenocarcinoma using microRNA expression (Review)

Treatment for locally-advanced rectal cancer (LARC) typically consists of neoadjuvant chemoradiation followed by total mesorectal excision. Recently, there has been growing interest in non-operative management for patients who are medically-inoperable or wish to avoid surgical morbidity and permanent colostomy. Approximately 50% of patients who receive pre-operative neoadjuvant chemoradiation develop some degree of pathologic response. Approximately 10-20% of patients are found to have a complete pathologic response, a finding which has frequently been shown to predict better clinical outcomes, including local-regional control, distant metastasis and survival. Many recent studies have evaluated the role of molecular biomarkers in predicting response to neoadjuvant therapy. MicroRNAs (miRNAs) are an emerging class of biomarkers that have the potential to predict which patients are most likely to benefit from pre-operative therapy and from a selective surgical approach. Here, we review the published literature on microRNAs as prognostic and predictive biomarkers in rectal cancer after pre-operative therapy. In the future, the development of prospectively validated miRNA signatures will allow clinical implementation of miRNAs as prognostic and predictive signatures in LARC.

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.

Baseline T Classification Predicts Early Tumor Regrowth After Nonoperative Management in Distal Rectal Cancer After Extended Neoadjuvant Chemoradiation and Initial Complete Clinical Response

BACKGROUND

Selected patients with rectal cancer and complete clinical response after neoadjuvant chemoradiation have been managed nonoperatively with acceptable outcomes. However, ≈20% of these patients will develop early tumor regrowth. Identification of these patients could select candidates for more intensive follow-up.

OBJECTIVE

The purpose of this study was to investigate the influence of baseline radiological T classification on recurrences after a complete clinical response managed nonoperatively after chemoradiation.

DESIGN

This was a retrospective review of a prospective collected database.

SETTINGS

The study was conducted at a single center.

PATIENTS

Patients with distal rectal cancer (cT2-4N0-2M0) undergoing extended chemoradiation (54 Gy + 5-fluorouracil-based chemotherapy) were eligible. Patients were reassessed for tumor response at 10 weeks after radiation completion. Patients with complete clinical response (clinical, radiological, and endoscopic) were managed nonoperatively and strictly followed.

MAIN OUTCOMES MEASURES

Complete clinical response rates, early tumor regrowth rates (<12 mo), local recurrence-free survival, and distant metastases-free survival were measured.

RESULTS

A total of 91 consecutive patients with rectal cancer underwent extended chemoradiation. Sixty-one patients developed initial complete clinical response (67%). cT2 patients developed similar initial complete clinical response rates compared with cT3/T4 (72% vs 63%; p = 0.403). Early tumor regrowths were more frequent among baseline cT3/4 when compared with cT2 patients (30% vs 3%; p = 0.007). There were no differences in late local recurrences (p = 0.593) or systemic recurrences (p = 0.387). Local recurrence-free survival was significantly better for cT2 patients at 1 year (96% vs 69%; p = 0.009). After Cox regression analysis, baseline T stage was an independent predictor of improved local recurrence-free survival at 1 year (p = 0.03; OR = 0.09 (95% CI, 0.01-0.81)).

LIMITATIONS

This study was limited by its small sample size, retrospective nature, and short follow-up.

CONCLUSIONS

cT2 patients who develop complete clinical response after extended chemoradiation managed nonoperatively are less likely to develop early tumor regrowths when compared with cT3/4 patients. cT3/4 patients should undergo more intensive follow-up after a complete clinical response to allow for early detection of early regrowths.

A watch-and-wait approach for locally advanced rectal cancer after a clinical complete response following neoadjuvant chemoradiation: a systematic review and meta-analysis

BACKGROUND

A watch-and-wait approach for patients with clinical complete response to neoadjuvant chemoradiation could avoid the morbidity of conventional surgery for rectal cancer. However, the safety of this approach is unclear. We synthesised the evidence for watch-and-wait as a treatment for rectal cancer.

METHODS

We systematically searched MEDLINE, Embase, and the grey literature (up to June 28, 2016) for studies of patients with rectal adenocarcinoma managed by watch-and-wait after complete clinical response to neoadjuvant chemoradiation. We determined the proportion of 2-year local regrowth after watch-and-wait. We assessed non-regrowth recurrence, cancer-specific mortality, disease-free survival, and overall survival from studies comparing patients who had watch-and-wait versus those who had radical surgery after detection of clinical complete response or versus patients with pathological complete response.

FINDINGS

We identified 23 studies including 867 patients with median follow-up of 12-68 months. Pooled 2-year local regrowth was 15·7% (95% CI 11·8-20·1); 95·4% (95% CI 89·6-99·3) of patients with regrowth had salvage therapies. There was no significant difference between patients managed with watch-and-wait after a clinical complete response and patients with pathological complete response identified at resection with respect to non-regrowth recurrence (risk ratio [RR] 1·46, 95% CI 0·70-3·05) or cancer-specific mortality (RR 0·87, 95% CI 0·38-1·99). Although there was no significant difference in overall survival between groups (hazard ratio [HR] 0·73, 95% CI 0·35-1·51), disease-free survival was better in the surgery group (HR 0·47, 95% CI 0·28-0·78). We found no significant difference between patients managed with watch-and-wait and patients with clinical complete response treated with surgery in terms of non-regrowth recurrence (RR 0·58, 95% CI 0·18-1·90), cancer-specific mortality (RR 0·58, 95% CI 0·06-5·84), disease-free survival (HR 0·56, 95% CI 0·20-1·60), or overall survival (HR 3·91, 95% CI 0·57-26·72).

INTERPRETATION

Most patients treated by watch-and-wait avoid radical surgery and of those who have regrowth almost all have salvage therapy. Although we detected no significant differences in non-regrowth cancer recurrence or overall survival in patients treated with watch-and-wait versus surgery, few patients have been studied and more prospective studies are needed to confirm long-term safety.

FUNDING

None.

Prediction of Pathological Complete Response Using Endoscopic Findings and Outcomes of Patients Who Underwent Watchful Waiting After Chemoradiotherapy for Rectal Cancer

BACKGROUND

Nonoperative management for patients with rectal cancer who have achieved a clinical complete response after chemoradiotherapy is becoming increasingly important in recent years. However, the definition of and modality used for patients with clinical complete response differ greatly between institutions, and the role of endoscopic assessment as a nonoperative approach has not been fully investigated.

OBJECTIVE

This study aimed to investigate the ability of endoscopic assessments to predict pathological regression of rectal cancer after chemoradiotherapy and the applicability of these assessments for the watchful waiting approach.

DESIGN

This was a retrospective comparative study.

SETTINGS

This study was conducted at a single referral hospital.

PATIENTS

A total of 198 patients with rectal cancer underwent preoperative endoscopic assessments after chemoradiotherapy. Of them, 186 patients underwent radical surgery with lymph node dissection.

MAIN OUTCOME MEASURES

The histopathological findings of resected tissues were compared with the preoperative endoscopic findings. Twelve patients refused radical surgery and chose watchful waiting; their outcomes were compared with the outcomes of patients who underwent radical surgery.

RESULTS

The endoscopic criteria correlated well with tumor regression grading. The sensitivity and specificity for a pathological complete response were 65.0% to 87.1% and 39.1% to 78.3%. However, endoscopic assessment could not fully discriminate pathological complete responses, and the outcomes of patients who underwent watchful waiting were considerably poorer than the patients who underwent radical surgery. Eventually, 41.7% of the patients who underwent watchful waiting experienced uncontrollable local failure, and many of these occurrences were observed more than 3 years after chemoradiotherapy.

LIMITATIONS

The number of the patients treated with the watchful waiting strategy was limited, and the selection was not randomized.

CONCLUSIONS

Although endoscopic assessment after chemoradiotherapy correlated with pathological response, it is unsuitable for surveillance of patients treated via a nonoperative approach. Incorporation of a "watchful waiting" strategy without establishing proper surveillance protocols and salvage strategies might result in poor local control.

Nonoperative Management or 'Watch and Wait' for Rectal Cancer with Complete Clinical Response After Neoadjuvant Chemoradiotherapy: A Critical Appraisal

BACKGROUND

There is increasing interest in nonoperative management (NOM) for rectal cancer with complete clinical response (cCR) after neoadjuvant chemoradiation (nCRT).

OBJECTIVE

The aim of this systematic review was to summarize the available data on NOM, with the intention of formulating standardized protocols on which to base future investigations.

METHODS

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted. A highly sensitive literature search identified all relevant studies published between January 2004 and December 2016. Data extraction and quality assessment was performed independently by two authors, and resolved by consensus with a third reviewer.

RESULTS

In total, 15 studies, including 920 patients, met the inclusion criteria; 575 (62.5%) of these patients underwent NOM after cCR, with the remaining patients forming a surgical control group. The weighted mean follow-up was 39.4 (12.7) months in the NOM group and 39.8 (5.1) months in the surgery group. The pooled regrowth rate in the NOM group was 21.3% at a mean of 15.6 (7.0) months. Surgical salvage was possible and was undertaken in 93.2% of these patients. Overall survival in the NOM group was 91.7%, while disease-free survival was 82.7%. For the comparison proctectomy group, pooled rates of local recurrence, overall survival, and disease-free survival were 8.4, 92.4, and 87.5%, respectively.

CONCLUSION

NOM may be a feasible option for surgically eligible rectal cancer patients with cCR after nCRT. Before such a strategy can be widely implemented, further prospective data are required with standardized definitions, diagnostic criteria, and management protocols, with an emphasis on shared patient-provider decision making and patient-centered outcomes.

Clinical utility of pretreatment prediction of chemoradiotherapy response in rectal cancer: a review

Approximately 20% of all patients with locally advanced rectal cancer experience pathologically complete responses following neoadjuvant chemoradiotherapy (CRT) and standard surgery. The utility of radical surgery for patients exhibiting good CRT responses has been challenged. Organ-sparing strategies for selected patients exhibiting complete clinical responses include local excision or no immediate surgery. The subjects of this tailored management are patients whose presenting disease corresponds to current indications of neoadjuvant CRT, and their post-CRT tumor response is assessed by clinical and radiological examinations. However, a model predictive of the CRT response, applied before any treatment commenced, would be valuable to facilitate such a personalized approach. This would increase organ preservation, particularly in patients for whom upfront CRT is not generally prescribed. Molecular biomarkers hold the greatest promise for development of a pretreatment predictive model of CRT response. A combination of clinicopathological, radiological, and molecular markers will be necessary to render the model robust. Molecular research will also contribute to the development of drugs that can overcome the radioresistance of rectal tumors. Current treatments for rectal cancer are based on the expected prognosis given the presenting disease extent. In the future, treatment schemes may be modified by including the predicted CRT response evaluated at presentation.

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.

Outcome and Salvage Surgery Following "Watch and Wait" for Rectal Cancer after Neoadjuvant Therapy: A Systematic Review

BACKGROUND

Currently there is no reliable test to predict pathological complete response following neoadjuvant chemoradiotherapy for rectal cancer. However, there is increasing interest in using clinical complete response as a surrogate marker, allowing a subset of patients with locally advanced rectal cancer to be allocated into a "watch and wait" pathway. Little is known about the oncological safety of the "watch and wait" approach or the rate of salvage surgery in cases of tumor regrowth. This information is critical for the implementation of this approach.

OBJECTIVE

The aim of this study is to assess the rate of salvage surgery and associated oncological outcomes for patients who develop a tumor regrowth with the "watch and wait" approach.

DATA SOURCES

Relevant studies were identified through PubMed, Embase, and Google Scholar search.

STUDY SELECTION

A systematic review was undertaken of studies assessing patients selected for the "watch and wait" approach according to PRISMA guidelines.

MAIN OUTCOME MEASURES

The associated tumor regrowth, salvage surgery, and disease-free and overall survival rates were assessed.

RESULTS

Five retrospective and 4 prospective observational studies were included into the analysis, with a total of 370 patients in the "watch and wait" group, of which 256 (69.2%) had persistent clinical complete response. Of those who had tumor regrowth, salvage surgery was possible in 83.8%. There was no difference in overall survival and disease-free survival between patients who received immediate surgery and the "watch and wait" group.

LIMITATIONS

The limitations of this study include its retrospective nature and small sample size. Furthermore, there is significant heterogeneity between study protocols, including the short median follow-up, given that tumor regrowth and distant metastasis may manifest at a later time point.

CONCLUSION

The majority of patients with tumor regrowth can be salvaged with definite surgery after "watch and wait." However, there is insufficient evidence to draw firm conclusions on the oncological safety of this approach; therefore, it is currently not the standard of care for locally advanced rectal cancer.

A single institution's long-term follow-up of patients with pathological complete response in locally advanced rectal adenocarcinoma following neoadjuvant chemoradiotherapy

PURPOSE

This paper aimed to study the long term follow-up of patients with primary rectal adenocarcinoma receiving neoadjuvant chemoradiotherapy who obtained a pathological complete response (pCR) and identify factors predicting complete response.

METHODS

Retrospective review of notes, histology, pre-operative full blood count and imaging of patients with primary rectal adenocarcinoma diagnosed in our institute from 2000 to 2012 from a prospectively maintained database were used. SPSS version 22.0 was used for statistical analysis.

RESULTS

Three hundred eighty patients diagnosed with primary rectal adenocarcinoma were identified, 277 received neoadjuvant chemoradiotherapy followed by curative resection. Forty-six patients obtained a pCR (ypT0N0) with no local recurrence and two metastatic recurrences on follow-up. Patients with a pCR have a significantly improved overall survival and disease-free survival compared to a non-pCR (150.0 and 136.1 vs 77.5 and 84.7 months, p = 0.001). On univariate analysis, increased tumour height above anal verge, low lymph node yield, high pre-operative haemoglobin and a low neutrophil-lymphocyte ratio are significant factors identifying a pCR. Multivariable analysis of the above factors confirmed tumour height above anal verge as significant in obtaining a pCR.

CONCLUSION

Patients with rectal adenocarcinoma who develop a pCR following neoadjuvant chemoradiotherapy have improved overall and disease-free survival. We have identified distance from anal verge, low lymph node yield, high pre-operative haemoglobin and low neutrophil-lymphocyte ratio as significant predictors of developing a pCR.

Avoiding Radical Surgery in Elderly Patients With Rectal Cancer Is Cost-Effective

BACKGROUND

Radical surgery is associated with significant perioperative mortality in elderly and comorbid populations. Emerging data suggest for patients with a clinical complete response after neoadjuvant chemoradiotherapy that a watch-and-wait approach may provide equivalent survival and oncological outcomes.

OBJECTIVE

The purpose of this study was to compare the cost-effectiveness of watch and wait and radical surgery for patients with rectal cancer after a clinical complete response following chemoradiotherapy.

DESIGN

Decision analytical modeling and a Markov simulation were used to model long-term costs, quality-adjusted life-years, and cost-effectiveness after watch and wait and radical surgery. Sensitivity analysis was used to investigate the effect of uncertainty in model parameters.

SETTINGS

A third-party payer perspective was adopted.

PATIENTS

Patients included in the study were a 60-year-old male cohort with no comorbidities, 80-year-old male cohorts with no comorbidities, and 80-year-old male cohorts with significant comorbidities.

INTERVENTIONS

Radical surgery and watch-and-wait approaches were studied.

MAIN OUTCOME MEASURES

Incremental cost, effectiveness, and cost-effectiveness ratio over the entire lifetime of the hypothetical patient cohorts were measured.

RESULTS

Watch and wait was more effective (60-year-old male cohort with no comorbidities = 0.63 quality-adjusted life-years (95% CI, 2.48-3.65 quality-adjusted life-years); 80-year-old male cohort with no comorbidities = 0.56 quality-adjusted life-years (95% CI, 0.52-1.59 quality-adjusted life-years); 80-year-old male cohort with significant comorbidities = 0.72 quality-adjusted life-years (95% CI, 0.34-1.76 quality-adjusted life-years)) and less costly (60-year-old male cohort with no comorbidities = $11,332.35 (95% CI, $668.50-$23,970.20); 80-year-old male cohort with no comorbidities = $8783.93 (95% CI, $2504.26-$21,900.66); 80-year-old male cohort with significant comorbidities = $10,206.01 (95% CI, $2762.014-$24,135.31)) independent of patient cohort age and comorbidity. Consequently, watch and wait was more cost-effective with a high degree of certainty (range, 69.6%-89.2%) at a threshold of $50,000/quality-adjusted life-year.

LIMITATIONS

Long-term outcomes were derived from modeled cohorts. Analysis was performed for a United Kingdom third-party payer perspective, limiting generalizability to other healthcare contexts.

CONCLUSIONS

Watch and wait is likely to be cost-effective compared with radical surgery. These findings strongly support the discussion of organ-preserving strategies with suitable patients.

Organ or sphincter preservation for rectal cancer. The role of contact X-ray brachytherapy in a monocentric series of 112 patients

BACKGROUND

Contact X-ray brachytherapy (CXB) has been used at Centre Antoine Lacassagne since 2002 to increase the chance of conservative treatment (organ or sphincter preservation) in rectal cancer. A consecutive series of 112 patients (pts) is reported.

METHODS

Three protocols were used in selected rectal adenocarcinomas. Group 1: T1 N0 treated with local excision (LE) followed by adjuvant CXB. Group 2: T2 or 'early' T3 N0 treated with CXB combined with chemoradiotherapy (CRT) followed by surveillance or LE. Group 3: distal 'locally advanced' T3 N0-2 treated with CXB and CRT before total proctectomy.

RESULTS

Group 1: 27 pt (pTis: 3; pT1: 21; pT2: 3). After LE with CXB alone (20 pt) or CXB + CRT (7 pt) one local recurrence occurred. Organ preservation was achieved in 26 pt (96%). Group 2: 45 pt (T1: 2; T2: 23; T3: 20) treated with CXB alone (4 pt) or CXB + CRT or external beam radiotherapy (EBRT) (41 pt). A clinical complete response (cCR) was observed in 43/45 (96%) and 3 pt developed a local recurrence (11% at 5 years). The specific survival was 76% at 5 years and the rate of organ preservation was 89% (40/45 pt) with good bowel function in 36 pt. Group 3: 40 pt, anterior resection (with sphincter preservation) was possible in 35 pt (86%) with a 3-year local recurrence of 6%.

CONCLUSION

CXB usually combined as a boost with CRT or EBRT may safely increase the chance of a conservative treatment (organ or sphincter preservation) for selected rectal cancers.

Organ preservation with local excision or active surveillance following chemoradiotherapy for rectal cancer

BACKGROUND

Organ preservation has been proposed as an alternative to radical surgery for rectal cancer to reduce morbidity and mortality, and to improve functional outcome.

METHODS

Locally advanced non-metastatic rectal cancers were identified from a prospective database. Patients staged ⩾T3 or any stage N+ were referred for neoadjuvant chemoradiotherapy (CRT) (50-54 Gy and 5-fluorouracil), and were reassessed 6-8 weeks post treatment. An active surveillance programme ('watch and wait') was offered to patients who were found to have a complete endoluminal response. Transanal excision was performed in patients who were found to have an objective clinical response and in whom a residual ulcer measured ⩽3 cm. Patients were followed up clinically, endoscopically and radiologically to assess for local recurrence or disease progression.

RESULTS

Of 785 patients with rectal cancer between 2005 and 2015, 362 had non-metastatic locally advanced tumours treated with neoadjuvant CRT. Sixty out of three hundred and sixty-two (16.5%) patients were treated with organ-preserving strategies - 10 with 'watch and wait' and 50 by transanal excision. Fifteen patients were referred for salvage total mesorectal excision post local excision owing to adverse pathological findings. There was no significant difference in overall survival (85.6% vs 93.3%, P=0.414) or disease-free survival rate (78.3% vs 80%, P=0.846) when the outcomes of radical surgery were compared with organ preservation. Tumour regrowth occurred in 4 out of 45 (8.9%) patients who had organ preservation.

CONCLUSIONS

Organ preservation for locally advanced rectal cancer is feasible for selected patients who achieve an objective endoluminal response to neoadjuvant CRT. Transanal excision defines the pathological response and refines decision-making.

Non-surgical management of rectal cancer. Series of 68 cases, long follow up in two leading centres in Argentina

BACKGROUND

The non-surgical management in a selected group of rectal cancer patients has shown promising results with adequate follow up.

AIMS

describing the results of the non-surgical management in patients with complete clinical response, with a close follow up.

METHODS

Between 2006 and 2015, patients with rectal cancer, stages I-III, without metastasis, treated with neoadjuvant CRT/CT, who had clinical complete response were included. CCR was defined through digital palpation, endoscopy-based criteria and MRI. Follow up was set according to institutional guidelines.

RESULTS

68 patients were included. Initial stage was assessed with MRI in 55/68 pts and EUS 11/68. Considering the recurrence risk factors 57.6% (29/68) were T2-3ab N0, 3.3% (2/68) were T4N0, 29% (20/68) were T3-4 N1-2, with 39.7% with positive MRC. Mean distance to the anal margin was 3cm. Chemoradiation included radiotherapy at 50.4cGy, and concurrent capecitabine. In 22% a fluoropirimidine and oxaliplatin-based schema was used as induction therapy. Median follow up was 37.5 months and response assessment time 9 weeks (5-19). Eleven patients recurred, 6 endoluminally, 3 developed mesorectal recurrence, and two distant failure. Five years DFS and OS were 76.3% and 93.8%.

CONCLUSIONS

conservative management was feasible with close follow up in leading cancer centres. In this series, DFS and OS were comparable to the data already reported in the literature.

High nodal positivity rates even in good clinical responders after chemoradiation of rectal cancer: is organ preservation feasible?

AIM

Local excision (LE) is emerging as a treatment option for rectal cancer responding well to chemoradiation. However, it does not address the mesorectal nodal burden. We aimed to identify the factors influencing nodal positivity and subsequently defined a low-risk group by including only patients at low risk.

METHOD

A single-centre, retrospective database analysis was carried out of patients with radically resected rectal cancer after neoadjuvant chemoradiation.

RESULTS

This study included 524 patients with predominantly low rectal tumours. Nodal positivity among ypT0, T1 and T2 groups was 14.7%, 28% and 30%, respectively. Multivariate analysis with stepwise logistic regression identified the following low-risk features: age ≥ 40 years, nonsignet ring cell carcinoma (SRCC) histology and pathological complete response (pCR). Sixty-nine patients fulfilling all three criteria were analysed and the nodal positivity was found to be 10.1%, which implies that, if these patients had been selected for LE, one in 10 would have had positive mesorectal nodes.

CONCLUSION

Even in patients with low-risk criteria (pCR, non-SRCC histology and age ≥ 40 years), the residual positive nodal disease burden is 10%. Whether this high incidence of residual nodal disease translates into a similar risk of locoregional recurrence if an organ-preservation strategy is adopted is unclear.

Magnetic Resonance Tumor Regression Grade and Residual Mucosal Abnormality as Predictors for Pathological Complete Response in Rectal Cancer Postneoadjuvant Chemoradiotherapy

BACKGROUND

Pathological complete response after chemoradiotherapy for rectal cancer occurs in 10% to 30% of patients. The best method to identify such patients remains unclear. Clinical assessment of residual mucosal abnormality is considered the most accurate method. In our institution, magnetic resonance tumor regression grade is performed as routine to assess response.

OBJECTIVE

The purpose of this study was to compare the sensitivity of magnetic tumor regression grade against residual mucosal abnormality in detecting patients with a pathological complete response.

DESIGN

Magnetic tumor regression grade scores from reported posttreatment MRI scans were documented. Magnetic tumor regression grade 1 to 3 was defined as likely to predict complete or near complete response. Gross appearances of the mucosa were derived from histopathology reports and used as a surrogate for clinical assessment (previously validated). Final histopathological staging was used to determine response.

SETTINGS

The study was conducted at Royal Marsden National Health Service Trust, United Kingdom.

PATIENTS

A total of 143 patients with rectal adenocarcinoma, diagnosed between September 1, 2009, and September 1, 2013, who received neoadjuvant chemoradiotherapy before curative surgery were included.

MAIN OUTCOME MEASURES

The sensitivity of magnetic tumor regression grade and residual mucosal abnormality in detecting patients with pathological complete response were measured

RESULTS

: Eighteen patients had a pathological complete response. Seventeen were detected using magnetic resonance tumor regression grade 1 to 3, with sensitivity 94% (95% CI, 0.74-0.99), and 10 were detected using residual mucosal abnormality, with sensitivity 62% (95% CI, 0.38-0.81). There was no statistical difference between the false positive rates for either method. Magnetic tumor regression grade identified 10 times more patients with a pathological complete response (diagnostic OR = 10.2 (95% CI, 1.30-73.73)) compared with clinical assessment with RMA.

LIMITATIONS

Residual mucosal abnormality was used as a surrogate marker for endoscopic appearances.

CONCLUSIONS

Most patients with rectal cancer who have a pathological complete response do not manifest a complete response at the mucosal level. Magnetic tumor regression grade is able to identify 10 times more patients than clinical assessment, with no significant compromise in the false positive rate.

Anorectal Cancer: Critical Anatomic and Staging Distinctions That Affect Use of Radiation Therapy

Although rectal and anal cancers are anatomically close, they are distinct entities with different histologic features, risk factors, staging systems, and treatment pathways. Imaging is at the core of initial clinical staging of these cancers and most commonly includes magnetic resonance imaging for local-regional staging and computed tomography for evaluation of metastatic disease. The details of the primary tumor and involvement of regional lymph nodes are crucial in determining if and how radiation therapy should be used in treatment of these cancers. Unfortunately, available imaging modalities have been shown to have imperfect accuracy for identification of nodal metastases and imaging features other than size. Staging of nonmetastatic rectal cancers is dependent on the depth of invasion (T stage) and the number of involved regional lymph nodes (N stage). Staging of nonmetastatic anal cancers is determined according to the size of the primary mass and the combination of regional nodal sites involved; the number of positive nodes at each site is not a consideration for staging. Patients with T3 rectal tumors and/or involvement of perirectal, mesenteric, and internal iliac lymph nodes receive radiation therapy. Almost all anal cancers warrant use of radiation therapy, but the extent and dose of the radiation fields is altered on the basis of both the size of the primary lesion and the presence and extent of nodal involvement. The radiologist must recognize and report these critical anatomic and staging distinctions, which affect use of radiation therapy in patients with anal and rectal cancers.

Distance to the anal verge is associated with pathologic complete response to neoadjuvant therapy in locally advanced rectal cancer

BACKGROUND AND OBJECTIVES

Achieving a pathologic complete response (pCR) after neoadjuvant therapy has been associated with better prognosis in rectal cancer patients. The objective of this study was to investigate the relationship between distance to the anal verge (DTAV) and pCR.

METHODS

Review of a prospectively maintained database of patients with locally advanced rectal cancer who received neoadjuvant treatment was completed. Uni- and multivariate analysis assessed the association between DTAV and pCR after neoadjuvant therapy.

RESULTS

Of 827 included patients, 20% had a pCR. We found that pCR rates were 11% for tumors <4 cm, 24% for tumors 4-6 cm, 30% for tumors at 6-8 cm, 17% for tumors 8-10 cm, and 14% for tumors >10 cm from the anal verge (P = 0.002). Multivariate analysis also showed a strong association between DTAV and pCR (P = 0.008). The bimodal distribution of pCR resulted in a lower odds ratio of pCR for tumors <4 and >8 cm from the anal verge.

CONCLUSIONS

Patients with low tumors (<4 cm) and higher tumors (>8 cm), were less likely to have a pCR. Further investigation is warranted to determine if these observations are related to tumor biology or possibly differences in radiation technique. J. Surg. Oncol. 2016;114:637-641. © 2016 Wiley Periodicals, Inc.

Contact radiotherapy boost in association with 'watch and wait' for rectal cancer: initial experience and outcomes from a shared programme between a district general hospital network and a regional oncology centre

AIM

Recent data have highlighted the potential of more intensive neoadjuvant protocols to increase and sustain the rate of complete response in rectal cancer managed nonoperatively. This study aimed to review the outcome of all patients from our district general hospitals network who had received standard neoadjuvant therapy and were additionally referred to a centre of excellence for contact X-ray brachytherapy or high-dose-rate brachytherapy boost.

METHOD

A retrospective, chart-based review of all patients co-managed in this manner was performed. Patient details were retrieved from a prospectively maintained departmental database. Indications for treatment, patient outcome and serial data from follow-up clinical and radiological assessment were analysed.

RESULTS

Seventeen patients treated over a 6-year period were identified. Median follow-up was 20 (5-54) months. Fourteen patients were clinically staged as T2 or T3 and eight were clinically node positive. Three patients died, of whom only one was initially a surgical candidate but refused an exenteration. Of the 14 patients who remain alive, 11 (79%) have a sustained complete (n = 8) or partial (n = 3) response. Two patients had an incomplete response, one is being palliated and the other awaits salvage surgery. One patient underwent abdominoperineal excision for suspected local recurrence. Currently 13 (93%) surviving patients are stoma free.

CONCLUSIONS

This series shows that the addition of a radiotherapy boost offered sustained responses and stoma-free survival even in advanced disease and adverse patient populations whilst providing the majority of care closer to home.

Long-term Outcome of an Organ Preservation Program After Neoadjuvant Treatment for Rectal Cancer

BACKGROUND

The aim of this study was to establish the oncological and functional results of organ preservation with a watch-and-wait approach (W&W) and selective transanal endoscopic microsurgery (TEM) in patients with a clinical complete or near-complete response (cCR) after neoadjuvant chemoradiation for rectal cancer.

METHODS

Between 2004 and 2014, organ preservation was offered if response assessment with digital rectal examination, endoscopy, and MRI showed (near) cCR. Watch-and-wait was offered for cCR, and two options were offered for near cCR: TEM or reassessment after three months. Follow-up included endoscopy and MRIs every three months during the first year, and every six months thereafter. Long-term outcome was assessed with Kaplan-Meier curves. Functional outcome was assessed with colostomy-free survival and Vaizey incontinence score (0 = perfect continence, 24 = totally incontinent).

RESULTS

One hundred patients were included, with median follow-up of 41.1 months. Sixty-one had cCR at initial response assessment. Thirty-nine had near cCR, of whom 24 developed cCR at the second assessment and 15 patients underwent TEM (9 ypT0, 1 ypT1, 5 ypT2). Fifteen patients developed a local regrowth (12 luminal, 3 nodal), all salvageable and within 25 months. Five patients developed metastases, and five patients died. Three-year overall survival was 96.6% (95% confidence interval [CI] = 89.9% to 98.9%), distant metastasis-free survival was 96.8% (95% CI = 90.4% to 99.0%), local regrowth-free survival was 84.6% (95% CI = 75.8% to 90.5%), and disease-free survival was 80.6% (95% CI = 70.9% to 87.4%). Colostomy-free survival was 94.8% (95% CI = 88.0% to 97.8%), with a good continence after watch-and-wait (Vaizey = 3.4, SD = 3.9) and moderate after TEM (Vaizey = 9.7, SD = 5.1).

CONCLUSIONS

Organ preservation appears oncologically safe for selected rectal cancer patients with a cCR or near cCR after neoadjuvant chemoradiation when applying strict selection criteria and frequent follow-up, including endoscopy and MRI. The low colostomy rate and the good long-term functional outcome warrant discussing this option with the patient as an alternative to major surgery.

Long-Term Outcome of Rectal Cancer With Clinically (EUS/MRI) Metastatic Mesorectal Lymph Nodes Treated by Neoadjuvant Chemoradiation: Role of Organ Preservation Strategies in Relation to Pathologic Response

BACKGROUND

Organ preservation strategies are under investigation for patients with locally advanced rectal cancer (LARC) who achieve a complete pathologic response in the primary tumor (ypT0) after neoadjuvant chemoradiation therapy (CRT). This study explored the value of this approach for cN+ patients.

METHODS

Data were retrieved from our institutional prospective rectal cancer database. Tumors with mesorectal lymph nodes larger than 5 mm shown on endorectal ultrasonography, pelvic magnetic resonance imaging, or both were staged as cN+.

RESULTS

The study population comprised 226 patients (142 men and 84 women; median age, 64 years) with LARC who underwent CRT followed by surgery including total mesorectal excision (TME) (n = 179) and full-thickness local excision (LE) (n = 47) between 1996 and 2013. At staging, 123 patients (54.4 %) were cN+. In 65 cases (28.7 %), ypCR was observed. Metastatic mesorectal lymph nodes (ypN+) were detected in 41.6 % of the cN+ patients and in 2.8 % of the cN0 patients (P < 0.01). Among the cN+ patients, 16 % of the ypT0 cases were ypN+ compared with 51.8 % of the no-ypT0 cases (P < 0.01). Among the cN+ patients who underwent TME, the 5-year disease-specific survival (DSS) and disease-free survival (DFS) rates were respectively 100 and 91.6 % for the ypT0 patients compared with 71.2 and 58.0 % for the no-ypT0 patients (P = 0.01). Among the ypN+ patients, the 5-year DSS and DFS rates were both 100 % for the ypT0 cases compared with 59.1 and 43.3 % for the no-ypT0 patients. Among the cN+ and ypT0 patients, the 5-year DSS and DFS were respectively 100 and 85.7 % for the TME patients compared with 100 and 91.6 % for the LE patients. In the multivariate analysis, ypT0 was the only independent prognostic factor.

CONCLUSIONS

Protocols aimed at organ preservation in LARC that achieve ypT0 after CRT can be offered also to cN+ patients.