High-dose chemoradiotherapy and watchful waiting for distal rectal cancer: a prospective observational study

Selection of Patients for Organ Preservation After Chemoradiotherapy: MRI Identifies Poor Responders Who Can Go Straight to Surgery

OBJECTIVE

The aim of this study was to evaluate whether magnetic resonance imaging (MRI) can accurately identify poor responders after chemoradiotherapy (CRT) who will need to go straight to surgery, and to evaluate whether results are reproducible among radiologists with different levels of expertise.

METHODS

Seven independent readers with different levels of expertise retrospectively evaluated the restaging MRIs (T2-weighted + diffusion-weighted imaging [T2W + DWI]) of 62 patients and categorized them as (1) poor responders - highly suspicious of tumor; (2) intermediate responders - tumor most likely; and (3) good - potential (near) complete responders. The reference standard was histopathology after surgery (or long-term follow-up in the case of a watch-and-wait program).

RESULTS

Fourteen patients were complete responders and 48 had residual tumor. The median percentage of patients categorized by the seven readers as 'poor', 'intermediate', and 'good' responders was 21% (range 11-37%), 50% (range 23-58%), and 29% (range 23-42%), respectively. The vast majority of poor responders had histopathologically confirmed residual tumor (73% ypT3-4), with a low rate (0-5%) of 'missed complete responders'. Of the 14 confirmed complete responders, a median percentage of 71% were categorized in the MR-good response group and 29% were categorized in the MR-intermediate response group.

CONCLUSIONS

Radiologists of varying experience levels should be able to use MRI to identify the ± 20% subgroup of poor responders who will definitely require surgical resection after CRT. This may facilitate more selective use of endoscopy, particularly in general settings or in centers with limited access to endoscopy.

Unintended consequences of treating early rectal cancers for complete clinical response with chemoradiotherapy

The aim was to examine the current trend in rectal cancer, which is to extend ’watch-and-wait’ to earlier-stage tumors, not normally treated with chemoradiotherapy, to define the up-side and down-side regarding quality of life (QOL) and anorectal/sexual/urinary function from this approach. We reviewed the literature regarding a ‘watch-and-wait’ strategy after neoadjuvant chemoradiotherapy. The primary outcome measure was complete clinical response. Secondary measures included colostomy rate, functional outcomes and QOL. There is a trend to use chemoradiotherapy in earlier tumors using dose-escalation of radiation and/or additional chemotherapy, resulting in high rates of complete clinical response, which may impact adversely on QOL if radical surgery is subsequently required. Focusing on organ-preservation as the primary goal of treatment rather than overall functional outcomes and QOL for the whole population, may not provide patients with sufficient information for optimal decision-making.

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.

The risk of distant metastases in rectal cancer managed by a watch-and-wait strategy - A systematic review and meta-analysis

BACKGROUND

The watch-and-wait (w&w) strategy is associated with frequent local regrowth (LR). Distant metastases (DM) occur more often in the patients with LR than in those without. However, it is unknown whether omitting immediate surgery results in the additional risk of DM.

MATERIALS/METHODS

A systematic review and meta-analysis were performed to determine the maximum risk of additional DM. To estimate this, we used data showing the proportions of DM in patients with and without LR, assuming that the excess DM in patients with LR may develop in two ways: from subclinical DM already present at baseline and due to seeding from the uncontrolled primary tumor, and that the incidence of subclinical DM at baseline in the LR subgroup is at least not lower than in the non-LR subgroup. Based on the calculated rate of excess DM in the LR subgroup we have obtained the rate for the whole group of patients undergoing w&w.

RESULTS

The maximum estimated risk of additional DM was 3.0% (95% CI: 1.2-4.9%) in the total group. After correction for short follow-up, the maximum risk at 5 years was 6.5%. Thus, the risk of excess DM is between 0% and 6.5%. Other evidence from a systematic review and the conservative assumptions taken for the calculation of the correction suggest that this maximum risk may be overestimated.

CONCLUSIONS

The additional risk of DM seems to be low. However, the high probability of bias, heterogeneity of the patients' population and low quality of evidence make our estimation uncertain.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Organ preservation with chemoradiotherapy plus local excision for rectal cancer: 5-year results of the GRECCAR 2 randomised trial

BACKGROUND

GRECCAR 2 was the first multicentre, randomised trial to compare local excision with total mesorectal excision in downstaged low rectal cancer. Encouraging oncological results were noted at 3 years' follow-up but needed to be corroborated with longer follow-up. In this study, we aimed to report the 5-year oncological outcomes, including local recurrence, metastatic disease, and survival.

METHODS

Patients age 18 years and older with T2T3 low rectal cancer, of maximum size 4 cm, who were clinically good responders after chemoradiotherapy (residual tumour ≤2 cm) were randomly assigned before surgery to either local excision or total mesorectal excision. Randomisation was centralised and not stratified and used permuted blocks of size eight. In the local excision group, a completion total mesorectal excision was performed if pathological tumour stage was ypT2-3. The primary objective of this study was to assess the 5-year oncological outcomes of local recurrence, metastatic disease, disease-free survival, overall survival, and cancer-specific mortality, which were the secondary endpoints of GRECCAR 2. We used Kaplan-Meier estimates and Cox modelling to estimate and compare recurrence and survival in modified intention-to-treat and as-treated populations. This trial was registered with ClinicalTrials.gov, number NCT00427375.

FINDINGS

Between March 1, 2007, and Sept 24, 2012, 148 patients who were good clinical responders were randomly assigned to treatment, three patients were excluded after randomisation (because they had metastatic disease, tumour >8 cm from anal verge, or withdrew consent), leaving 145 for analysis: 74 in the local excision group and 71 in the total mesorectal excision group. Median follow-up was 60 months (IQR 58-60) in the local excision group and 60 months (57-60) in the total mesorectal excision group. 23 patients died and five were lost to follow-up. In the local excision group, 26 had a completion total mesorectal excision for ypT2-3 tumour. In the modified intention-to-treat analysis, there was no difference between the local excision and total mesorectal excision groups in 5-year local recurrence (7% [95% CI 3-16] vs 7% [3-16]; adjusted hazard ratio [HR] 0·71 [95% CI 0·19-2·58]; p=0·60), metastatic disease (18% [CI 11-30] vs 19% [11-31]; 0·86 [0·36-2·06]; p=0·73), overall survival (84% [73-91] vs 82% [71-90]; 0·92 [0·38-2·22]; p=0·85), disease-free survival (70% [58-79] vs 72% [60-82]; 0·87 [0·44-1·72]; p=0·68), or cancer-specific mortality (7% [3-17] vs 10% [5-20]; 0·65 [0·17-2·49]; p=0·53).

INTERPRETATION

The 5-year results of this multicentre randomised trial corroborate the 3-year results, providing no evidence of difference in oncological outcomes between local excision and total mesorectal excision. Local excision can be proposed in selected patients having a small T2T3 low rectal cancer with a good clinical response after chemoradiotherapy.

FUNDING

National Cancer Institute of France.

Reporting colon cancer staging using a template

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Template reporting increases key colon tumour descriptors.

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Template reporting was used for less than a third of the patients.

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High risk of underreporting.

Purpose

The purpose of this study was to evaluate the effect of completeness of the radiological reports in primary local staging colon cancer when using a template.

Methods

The study used primary staging reports retrieved from the departments RIS/PACS. Five key tumour descriptors were evaluated within each report: tumour morphology (polypoid or annular), information on tumour breach of the colon wall (≥ T3), tumour out-growth in mm, nodal status and TNM in conclusion. The failure to provide a description of the presence or absence of a feature in a report counted as ‘not reported’. To allow comparisons between reporting styles, the template or free-text style of reporting was also recorded.

Results

During a two year period, a total of 666 patients CT reports were evaluated at the colorectal center multidisciplinary team (MDT) conference. In 200 of these reports a template was used. Information on tumour morphology (polypoid or annular) was present in 81% of the template reports vs 9% in free-text style. The figures in percentage for information on tumour breach of the colon wall (≥ T3) were 93% vs 48 %, tumour out-growth in mm: 51% vs 17%, nodal status: 99% vs 86% and TNM in conclusion: 98% vs 51%. P < 0.0001.

Conclusion

The present study provides additional support for the routine use of template reports to improve imaging reporting standards in colonic cancer.

Knowledge-based automatic optimization of adaptive early-regression-guided VMAT for rectal cancer

PURPOSE

To implement a knowledge-based (KB) optimization strategy to our adaptive (ART) early-regression guided boosting technique in neo-adjuvant radio-chemotherapy for rectal cancer.

MATERIAL AND METHODS

The protocol consists of a first phase delivering 27.6 Gy to tumor/lymph-nodes (2.3 Gy/fr-PTV₁), followed by the ART phase concomitantly delivering 18.6 Gy (3.1 Gy/fr) and 13.8 Gy (2.3 Gy/fr) to the residual tumor (PTV_ART) and to PTV₁ respectively. PTV_ART is obtained by expanding the residual GTV, as visible on MRI at fraction 9. Forty plans were used to generate a KB-model for the first phase using the RapidPlan tool. Instead of building a new model, a robust strategy scaling the KB-model to the ART phase was applied. Both internal and external validation were performed for both phases: all automatic plans (RP) were compared in terms of OARs/PTVs parameters against the original plans (RA).

RESULTS

The resulting automatic plans were generally better than or equivalent to clinical plans. Of note, V_30Gy and V_40Gy were significantly improved in RP plans for bladder and bowel; gEUD analysis showed improvement for KB-modality for all OARs, up to 3 Gy for the bowel.

CONCLUSIONS

The KB-model generated for the first phase was robust and it was also efficiently adapted to the ART phase. The performance of automatically generated plans were slightly better than the corresponding manual plans for both phases.

Role of radiotherapy in the treatment of rectal cancer in older patients

Striking a balance between cancer treatment and patient-centred care is becoming ever more important in older patients with rectal cancer as the population is ageing. The treatment decision made by the modern multidisciplinary colorectal team will recommend pre-operative chemo-radiotherapy followed by surgery for advance rectal cancer and surgery alone for early rectal cancer, as the "standard of care" is surgery. However, an alternative non-surgical treatment option should be consider for older patients with rectal cancer as the surgical harm can far outweigh the potential benefits. There is published evidence that mortality is higher with increasing age. An alternative treatment option to surgery when patients are not suitable or refusing surgery is to offer them external beam radiotherapy (EBRT) or chemo radiotherapy (EBCRT). A proportion of these patients can achieve a clinical complete response (cCR) which enable adoption of 'watch and wait' strategy to avoid surgery. However, a third of patients who achieved initial cCR can develop local regrowth within the first two years. This require salvage surgery which reduces their chance of organ preservation. Contact X-ray brachytherapy (CXB) or High Dose Rate Endo Brachy Therapy (HDREBT) boost following external beam radiotherapy can improve the initial cCR rate and reduce the risk of local regrowth. Those patients with persistent residual cancer or regrowth after brachytherapy boost following EBCRT or EBRT can have salvage surgery later without compromising their chance of cure. Therefore, patients should be fully aware of their treatment options and have 'a choice' when deciding and consenting their treatment.

Magnetic Resonance Guided Radiotherapy for Rectal Cancer: Expanding Opportunities for Non-Operative Management

Colorectal cancer is the third most common cancer in men and the second most common in women worldwide, and the incidence is increasing among younger patients. 30% of these malignancies arise in the rectum. Patients with rectal cancer have historically been managed with preoperative radiation, followed by radical surgery, and adjuvant chemotherapy, with permanent colostomies in up to 20% of patients. Beginning in the early 2000s, non-operative management (NOM) of rectal cancer emerged as a viable alternative to radical surgery in select patients. Efforts have been ongoing to optimize neoadjuvant therapy for rectal cancer, thereby increasing the number of patients potentially eligible to forgo radical surgery. Magnetic resonance guided radiotherapy (MRgRT) has recently emerged as a treatment modality capable of intensifying preoperative radiation therapy for rectal cancer patients. This technology may also predict which patients will achieve a complete response to preoperative therapy, thereby allowing for more appropriate selection of patients for NOM. The present work seeks to illustrate the potential role MRgRT could play in personalizing rectal cancer treatment thus expanding the role of NOM in rectal cancer.

Prognosis comparison between wait and watch and surgical strategy on rectal cancer patients after treatment with neoadjuvant chemoradiotherapy: a meta-analysis

BACKGROUND

After achieving a clinical complete response through neoadjuvant chemoradiotherapy, a nonoperative management approach for rectal cancer patients known as Wait and Watch (W&W) has gained increasing attention. However, the W&W strategy has been related to higher local recurrence and ambiguous long-term survival. This meta-analysis compared key prognosis indicators between W&W and surgical treatment in an effort to clarify some long-standing points of confusion.

METHODS

Pubmed, Web of Science, EMbase, Cochrane Library were searched for relevant researches comparing W&W with surgery treatment, with a time criteria set from 1 January 2002 to 4 July 2019. Endpoints were 2-year local regrowth/recurrence, 2-year distant metastasis (plus local regrowth/recurrence), 3- and 5-year disease-free survival (DFS), and overall survival (OS).

RESULTS

In total, nine studies with 801 patients were enrolled, of which 348 were managed by W&W and 453 by surgery. Surgery patients were further divided into a pathological complete response (pCR) group (all included patients achieved pCR) and a surgery group (consisting of both pCR and non-pCR patients without deliberate screening). Compared with the surgery group, W&W patients have higher 3- and 5-year OS, and are not inferior on 2-year local regrowth (LR), 2-year distant metastasis (DM)/DM+LR, and 3- and 5-year DFS. On the other hand, compared with the pCR group, the W&W group is inferior on 2-year LR, 3- and 5-year DFS, and 5-year OS, and not inferior on 2-year DM/DM+LR and 3-year OS.

CONCLUSIONS

In contrast with patients undergoing surgical treatment, the W&W group has higher 3- and 5-year OS, and is not inferior on other major prognostic indicators, which, however, is based on the fact that the tumor stage in the W&W group is generally earlier. Versus surgically treated patients who acquired pCR, W&W group is inferior on all major prognostic indicators except 2-year DM/DM+LR and 3-year OS. Additionally, by comparison of cCR definitions across different studies, we conclude that implementation of the strictest cCR criteria is critical for W&W patients to acquire maximum prognostic benefit.

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

Radiation therapy for rectal cancer

Radiotherapy (RT) has remained an important pillar in the multi-modality management of rectal cancer. Adjuvant RT with concurrent chemotherapy (chemo-RT) was once the standard of care for locally advanced rectal cancer, but with time, that has now changed and neoadjuvant chemo-RT followed by total mesorectal excision (TME) surgery is the new standard. Alternatively, neoadjuvant RT alone remains an option and clinicians are tasked to choose between the two. In an era of personalised oncological management, it is unsurprising that the treatment for rectal cancer is following suit and upcoming trials are studying ways to improve outcomes and minimise toxicity for patients while tailoring treatments specific to each patient's tumour. We review the evolution of the role of RT in rectal cancer and look forward to what the future holds.

Long-course neoadjuvant chemoradiotherapy with versus without a concomitant boost in locally advanced rectal cancer: a randomized, multicenter, phase II trial (FDRT-002)

Background

This study was designed to explore whether an intensified chemoradiotherapy (CRT) led to a better clinical outcome in locally advanced rectal cancer.

Methods

Patients with stage II/III rectal cancer were randomly allocated to receive either pelvic intensity-modulated radiation therapy (IMRT) of 50 Gy/25Fx concurrently with capecitabine and oxaliplatin (Arm A), or pelvic radiation of 50 Gy/25Fx with a concomitant boost of 5 Gy to the primary lesion, followed by a cycle of XELOX 2 weeks after the end of CRT (Arm B). All patients were planned to receive a definitive operation 8 weeks after the completion of CRT and a total of six perioperative chemotherapy cycles of capecitabine and oxaliplatin regardless of pathological result. Pathological complete response (ypCR) was the primary endpoint.

Results

From February 2010 to December 2011, 120 patients from three centers were enrolled in this study. Ninety-five percent patients completed a full-dose chemoradiotherapy as planning. Then 53 and 57 patients received a radical surgery, and 8 and 14 cases were confirmed as ypCR in two groups (P = 0.157). The other 10 patients failed to receive a definitive resection because of unresectable disease. Similar toxicities were observed between two groups and more incision healing delay were found in Arm B (3 vs.13, P = 0.011). No statistical differences were observed in local-regional control (P = 0.856), disease-free survival (P = 0.349) and overall survival (P = 0.553). Mesorectal fascia (MRF) involvement was an independent prognostic factor for survival in multivariate analysis.

Conclusions

A concomitant boost to oxalipatin-combined preoperative chemoradiotherapy demonstrated a slightly higher pCR rate but delayed incision healing after surgery. The impact of MRF involvement on survival merits further investigations.

Trial registration

NCT01064999 (ClinicalTrials.gov).

Long-term Oncological and Functional Outcomes of Chemoradiotherapy Followed by Organ-Sparing Transanal Endoscopic Microsurgery for Distal Rectal Cancer: The CARTS Study

Importance

Treatment of rectal cancer is shifting toward organ preservation aiming to reduce surgery-related morbidity. Short-term outcomes of organ-preserving strategies are promising, but long-term outcomes are scarce in the literature.

Objective

To explore long-term oncological outcomes and health-related quality of life (HRQL) in patients with cT1-3N0M0 rectal cancer who underwent neoadjuvant chemoradiotherapy (CRT) followed by transanal endoscopic microsurgery (TEM).

Design, Setting, and Participants

In this multicenter phase II feasibility study, patients with cT1-3N0M0 rectal cancer admitted to referral centers for rectal cancer throughout the Netherlands between February 2011 and September 2012 were prospectively included. These patients were to be treated with neoadjuvant CRT followed by TEM in case of good response. An intensive follow-up scheme was used to detect local recurrences and/or distant metastases. Data from validated HRQL questionnaires and low anterior resection syndrome questionnaires were collected. Data were analyzed from February 2011 to April 2017.

Main Outcomes and Measures

The primary study outcome of the study was the number of ypT0-1 specimens by performing TEM. Secondary outcome parameters were locoregional recurrences and HRQL.

Results

Of the 55 included patients, 30 (55%) were male, and the mean (SD) age was 64 (39-82) years. Patients were followed up for a median (interquartile range) period of 53 (39-57) months. Two patients (4%) died during CRT, 1 (2%) stopped CRT, and 1 (2%) was lost to follow-up. Following CRT, 47 patients (85%) underwent TEM, of whom 35 (74%) were successfully treated with local excision alone. Total mesorectal excision was performed in 16 patients (4 with inadequate responses, 8 with completion after TEM, and 4 with salvage for local recurrence). The actuarial 5-year local recurrence rate was 7.7%, with 5-year disease-free and overall survival rates of 81.6% and 82.8%, respectively. Health-related quality of life during follow-up was equal to baseline, with improved emotional well-being in patients treated with local excision (mean score at baseline, 72.0; 95% CI, 67.1-80.1; mean score at follow-up, 86.9; 95% CI, 79.2-94.7; P = .001). Major, minor, and no low anterior resection syndrome was experienced in 50%, 28%, and 22%, respectively, of patients with successful organ preservation.

Conclusions and Relevance

In early-stage rectal cancer (cT1-3N0M0), CRT enables organ preservation with additional TEM surgery in approximately two-thirds of patients with good long-term oncological outcome and HRQL. This multimodality treatment triggers a certain degree of bowel dysfunction, and one-third of patients still undergo radical surgery and are overtreated by CRT.

Microscopic intramural extension of rectal cancer after neoadjuvant chemoradiation: A meta-analysis based on individual patient data

OBJECTIVE

In selected rectal cancer patients with residual local disease following neoadjuvant chemoradiation (CRT) and the preference of an organ preservation pathway, additional treatment with dose escalation by endoluminal radiotherapy (RT) may ultimately result in a clinical complete response. To date, the widespread introduction of selective endoluminal radiation techniques is hampered by a lack of evidence-based guidelines that describe the radiation treatment volume in relation to the residual tumor mass. In order to convert an incomplete response into a complete one with additional treatment such as dose-escalation with endoluminal RT from a theoretical perspective, it seems important to treat all remaining microscopic tumor cells after CRT. In this setting, residual tumor extension beneath normal appearing mucosa (microscopic intramural spread - MIS) becomes relevant for accurate tumor volume and margin estimation. With the goal of providing evidence-based guidelines that define an appropriate treatment volume and patient selection, we present results from a meta-analysis based on individual patient data of studies that have assessed the extent or range of MIS of rectal cancers after neoadjuvant CRT. This meta-analysis should provide an estimate of the residual tumor volume/extension that needs to be targeted by any additional radiation therapy boost in order to achieve complete tumor eradication after initial incomplete or near-complete response following standard CRT.

METHODS AND MATERIALS

A PubMed search was performed. Additional articles were selected based on identification from reference lists. Papers were eligible when reporting MIS in patients who were treated by total mesorectal excision or local excision/transanal endoscopic microsurgery (TEM) after neo-adjuvant long-course CRT. The mean MIS was calculated for the entire group along with the 70th until 95th percentiles. Additional exploratory subgroup analyses were performed.

RESULTS

Individual patient data from 349 patients with residual disease from five studies were analyzed. 80% of tumors showed no MIS. In order to appropriately treat MIS in 95% of rectal cancer patients after CRT, a margin of 5.5 mm around the macroscopic tumor would suffice. An exploratory subgroup analysis showed that T-stage after CRT (ypT) and time interval between neoadjuvant CRT and surgery are significant factors predicting the extent of MIS (p < 0.001.) The group of ypT1 had the smallest MIS, followed by the ypT3-4 group, while the ypT2 group had the largest MIS (p < 0.001). Regarding time interval between CRT and surgery, a statistically significant difference was seen when comparing the three time-interval groups (less than 8 weeks, 8-12 weeks, and more than 12 weeks), where waiting more than 12 weeks after CRT resulted in the largest MIS (p < 0.0001).

CONCLUSION

Based on this meta-analysis, in order to treat the MIS for 95% of rectal cancer patients after CRT, a Clinical Target Volume (CTV) margin of 5.5 mm from the lateral most edge of the macroscopic tumor would suffice. 80% of tumors showed no MIS and would not require an extra CTV margin for treatment. These findings support the feasibility of localized radiotherapy boosts for dose-escalation to improve response among patients with incomplete response after standard CRT and can also be applied in the surgical setting.

Long-Term Patient-Reported Outcomes After High-Dose Chemoradiation Therapy for Nonsurgical Management of Distal Rectal Cancer

PURPOSE

Surgery is standard treatment for rectal cancer, but neoadjuvant chemoradiation therapy (CRT) may result in clinical complete response (cCR) in select patients, allowing for nonsurgical management (NSM). Prospective studies of NSM strategies are sparse, however, and long-term data on quality of life (QoL) are limited. We conducted a single-arm phase 2 trial of high-dose CRT for NSM of distal rectal cancer; we report secondary long-term patient-reported outcomes (PROs), local regrowth, and overall survival in patients managed nonsurgically.

METHODS AND MATERIALS

Fifty-one patients with resectable, T2 or T3, N0-N1, low adenocarcinoma received 65 Gy (intensity modulated radiation therapy, brachytherapy boost) and oral tegafur-uracil. Patients with cCR 6 weeks after treatment (clinical examination, magnetic resonance imaging, biopsy) were referred for observation and followed closely with clinical examination, endoscopy, positron emission tomography/computed tomography, and PROs for 5 years. Overall colorectal cancer-specific QoL and specific symptom scores were evaluated at baseline and in follow-up and compared between time points. Local regrowth was estimated using cumulative incidence and overall survival using Kaplan-Meier estimates.

RESULTS

Forty patients achieved cCR after treatment; 29 were in follow-up at 24 months, 21 at 36 months, and 20 at 60 months. PRO questionnaire completion rates were 90% at 24 months, 100% at 36 months, and 85% at 60 months for patients still in follow-up. Average QoL score did not differ between baseline (median 11.1) and 24 months (13.7), 48 months (11.1), or 60 months (6.9). Only rectal bleeding deteriorated from baseline, with bowel- and bladder-related symptom scores otherwise unchanged in follow-up. At median follow-up of 5.0 years, local regrowth rate and overall survival were 31% (95% confidence interval, 15%-47%) and 85% (95% confidence interval, 75%-97%), respectively.

CONCLUSIONS

Long-term follow-up after NSM of distal rectal cancer showed excellent general colorectal cancer QoL and local symptom scores. Our study results indicate that high-dose CRT followed by organ preservation might be an alternative to standard treatment.

Population-based study of morbidity risk associated with pathological complete response after chemoradiotherapy for rectal cancer

Background

Neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer may induce a pathological complete response (pCR) but increase surgical morbidity due to radiation-induced fibrosis. In this study the association between pCR and postoperative surgical morbidity was investigated.

Methods

Patients in the Netherlands with rectal cancer who underwent nCRT followed by total mesorectal excision between 2009 and 2017 were included. Data were stratified into patients who underwent resection with creation of a primary anastomosis and those who had a permanent stoma procedure. The association between pCR and postoperative morbidity was investigated in univariable and multivariable logistic regression analyses.

Results

pCR was observed in 976 (12·2 per cent) of 8003 patients. In 3472 patients who had a primary anastomosis, the presence of pCR was significantly associated with surgical complications (122 of 443 (27·5 per cent) versus 598 of 3029 (19·7 per cent) in those without pCR) and anastomotic leak (35 of 443 (7·9 per cent) versus 173 of 3029 (5·7 per cent) respectively). Multivariable analysis also showed associations between pCR and surgical complications (adjusted odds ratio (OR) 1·53, 95 per cent c.i. 1·22 to 1·92) and pCR and anastomotic leak (adjusted OR 1·41, 1·03 to 2·05). Of 4531 patients with a permanent stoma, surgical complications were observed in 120 (22·5 per cent) of 533 patients with a pCR, compared with 798 (20·0 per cent) of 3998 patients with no pCR (adjusted OR 1·17, 0·94 to 1·46).

Conclusion

Patients with a pCR in whom an anastomosis was created were at increased risk of developing an anastomotic leak.

Organ Preservation in cT2N0 Rectal Cancer After Neoadjuvant Chemoradiation Therapy: The Impact of Radiation Therapy Dose-escalation and Consolidation Chemotherapy

OBJECTIVE

To demonstrate the difference in organ-preservation rates and avoidance of definitive surgery among cT2N0 rectal cancer patients undergoing 2 different chemoradiation (CRT) regimens.

BACKGROUND

Patients with cT2N0 rectal cancer are more likely to develop complete response to neoadjuvant CRT. Organ preservation has been considered an alternative treatment strategy for selected patients. Radiation dose-escalation and consolidation chemotherapy have been associated with increased rates of response and may improve chances of organ preservation among these patients.

METHODS

Patients with distal and nonmetastatic cT2N0 rectal cancer managed by neoadjuvant CRT were retrospectively reviewed. Patients undergoing standard CRT (50.4 Gy and 2 cycles of 5-FU-based chemotherapy) were compared with those undergoing extended CRT (54 Gy and 6 cycles of 5-FU-based chemotherapy). Patients were assessed for tumor response at 8 to 10 weeks. Patients with complete clinical response (cCR) underwent organ-preservation strategy ("Watch and Wait"). Patients were referred to salvage surgery in the event of local recurrence during follow-up.

RESULTS

Thirty-five patients underwent standard and 46 patients extended CRT. Patients undergoing extended CRT were more likely to undergo organ preservation and avoid definitive surgical resection at 5years (67% vs 30%; P = 0.001). After development of a cCR, surgery-free survival is similar between extended and standard CRT groups at 5 years (78% vs 56%; P = 0.12).

CONCLUSIONS

Dose-escalation and consolidation chemotherapy leads to increased long-term organ-preservation rates among cT2N0 rectal cancer. After achievement of a cCR, the risk for local recurrence and need for salvage surgery is similar, irrespective of the CRT regimen.

Emerging trends in the treatment of rectal cancer

The conventional treatment for cT3-T4 or node-positive clinically resectable rectal cancer is long course preoperative chemoradiation followed by surgery and postoperative adjuvant chemotherapy. Disadvantages of this approach include possible overtreatment of patients, 6 weeks of daily radiation treatment, and undetected metastatic disease. There are a number of emerging trends which are changing this approach to treatment. Selected topics included in this manuscript include the selective use of pelvic radiation, the role of radiation for a positive radial margin, the interval between radiation and surgery, non-operative management, new chemoradiation regimens, short vs. long course radiation, and the role of postoperative adjuvant chemotherapy.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes

AIM

Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes.

METHOD

We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015.

RESULTS

In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002).

CONCLUSION

Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.

Neoadjuvant radiotherapy for rectal cancer management

Thirty per cent of all colorectal tumours develop in the rectum. The location of the rectum within the bony pelvis and its proximity to vital structures presents significant therapeutic challenges when considering neoadjuvant options and surgical interventions. Most patients with early rectal cancer can be adequately managed by surgery alone. However, a significant proportion of patients with rectal cancer present with locally advanced disease and will potentially benefit from down staging prior to surgery. Neoadjuvant therapy involves a variety of options including radiotherapy, chemotherapy used alone or in combination. Neoadjuvant radiotherapy in rectal cancer has been shown to be effective in reducing tumour burden in advance of curative surgery. The gold standard surgical rectal cancer management aims to achieve surgical removal of the tumour and all draining lymph nodes, within an intact mesorectal package, in order to minimise local recurrence. It is critically important that all rectal cancer cases are discussed at a multidisciplinary meeting represented by all relevant specialties. Pre-operative staging including CT thorax, abdomen, pelvis to assess for distal disease and magnetic resonance imaging to assess local involvement is essential. Staging radiology and MDT discussion are integral in identifying patients who require neoadjuvant radiotherapy. While Neoadjuvant radiotherapy is potentially beneficial it may also result in morbidity and thus should be reserved for those patients who are at a high risk of local failure, which includes patients with nodal involvement, extramural venous invasion and threatened circumferential margin. The aim of this review is to discuss the role of neoadjuvant radiotherapy in the management of rectal cancer.

Systematic review and meta-analysis on outcomes of salvage therapy in patients with tumour recurrence during 'watch and wait' in rectal cancer

INTRODUCTION

The 'watch and wait' approach has recently emerged as an alternative approach for managing patients with complete clinical response in rectal cancer. However, less is understood whether the intervention is associated with a favourable outcome among patients who require salvage therapy following local recurrence.

MATERIALS AND METHODS

A comprehensive systematic search was performed using EMBASE, PubMed, MEDLINE, Journals@Ovid as well as hand searches; published between 2004 and 2018, to identify studies where outcomes of patients undergoing watch and wait were compared with conventional surgery. Study quality was assessed using the Newcastle-Ottawa assessment scale. The main outcome was relative risks for overall and disease specific mortality in salvage therapy.

RESULTS

Nine eligible studies were included in the meta-analysis. Of 248 patients who followed the watch and wait strategy, 10.5% had salvage therapy for recurrent disease. No statistical heterogeneity was found in the results. The relative risk of overall mortality in the salvage therapy group was 2.42 (95% confidence interval 0.96-6.13) compared with the group who had conventional surgery, but this was not statistically significant (P > 0.05). The relative risk of disease specific mortality in salvage therapy was 2.63 (95% confidence interval 0.81-8.53).

CONCLUSION

Our findings demonstrated that there was no significant difference in overall and disease specific mortality in patients who had salvage treatment following recurrence of disease in the watch and wait group compared with the standard treatment group. However, future research into the oncological safety of salvage treatment is needed.

Liquid biopsy for rectal cancer: A systematic review

BACKGROUND

The management of locally advanced rectal cancer (RC) is an evolving clinical field where the multidisciplinary approach can reach its best, and liquid biopsy for obtaining tumor-derived component such as circulating tumor DNA (ctDNA) might provide complementary informations.

METHODS

A systematic review of studies available in literature of liquid biopsy in non-metastatic RC has been performed according to PRISMA criteria to assess the role of ctDNA as a diagnostic, predictive and prognostic biomarker in this setting.

RESULTS

Twenty-five publications have been retrieved, of which 8 full-text articles, 7 abstracts and 10 clinical trials. Results have been categorized into three groups: diagnostic, predictive and prognostic. Few but promising data are available about the use of liquid biopsy for early diagnosis of RC, with the main limitation of sensitivity due to low concentrations of ctDNA in this setting. In terms of prediction of response to chemoradiation, still inconclusive data are available about the utility of a pre-treatment liquid biopsy, whereas some studies report a positive correlation with a dynamic (pre/post-treatment) monitoring. The presence of minimal residual disease by ctDNA was consistently associated with worse prognosis across studies.

CONCLUSIONS

The use of liquid biopsy for monitoring response to chemoradiation and assess the risk of disease recurrence are the most advanced potential applications for liquid biopsy in RC, with implications also in the context of non-operative management strategies.

Image Guided Adaptive Endorectal Brachytherapy in the Nonoperative Management of Patients With Rectal Cancer

PURPOSE

Organ preservation or nonoperative management of rectal cancer is of growing interest. Image guided adaptive endorectal brachytherapy is a radiation dose escalation modality: we explored its role in elderly patients unfit for surgery and patients refusing surgery.

METHODS AND MATERIALS

In this registry study, patients with rectal cancer who were ineligible for surgery received 40 Gy in 16 fractions of pelvic external beam radiation therapy. They subsequently received 3 weekly image guided adaptive brachytherapy boosts of 10 Gy to the residual tumor, for a total of 30 Gy in 3 fractions. Complete clinical response (cCR) and local control were the primary endpoints.

RESULTS

94 patients were included; the median age was 81.1 years. With a median follow-up of 1.9 years, the proportion of cCR was 86.2%, the tumor regrowth proportion was 13.6%, and the cumulative incidence of local relapse was 2.7% at 1 year and 16.8% at 2 years. When considering responders and nonresponders, the 2-year local control was 71.5%. The overall survival at 2 years was 63.6%. Acute rectal grade 1 to 2 toxicity included all patients: 12.8% of patients had late bleeding requiring iron replacement, blood transfusions, or argon plasma therapy.

CONCLUSIONS

Results of this registry study, evaluating radiation dose escalation for elderly medically unfit patients with unselected tumors, reveal that a high proportion of patients achieved cCR with a manageable toxicity profile. This technology will likely contribute to the challenging nonoperative management paradigm of rectal cancer.

Oncological and Survival Outcomes in Watch and Wait Patients With a Clinical Complete Response After Neoadjuvant Chemoradiotherapy for Rectal Cancer: A Systematic Review and Pooled Analysis

OBJECTIVE

The aim of this study was to evaluate the oncological and survival outcomes of a Watch and Wait policy in rectal cancer after a clinical complete response (cCR) following neoadjuvant chemoradiotherapy.

BACKGROUND

The detection of a cCR after neoadjuvant treatment may facilitate a nonoperative approach in selected patients. However, the long-term safety of this strategy remains to be validated.

METHOD

This is a systematic review of the literature to determine the oncological outcomes in Watch and Wait patients. The primary outcome was the cumulative rate of local regrowth, success of salvage surgery, and incidence of metastases. We also evaluated survival outcomes. A pooled analysis of manually extracted summary statistics from individual studies was carried out using inverse variance weighting.

RESULTS

Seventeen studies comprising 692 patients were identified; incidence of cCR was 22.4% [95% confidence interval (CI),14.3-31.8]. There were 153 (22.1%) local regrowths, of which 96% (n = 147/153) manifested in the first 3 years of surveillance. The 3-year cumulative risk of local regrowth was 21.6% (95% CI, 16.0-27.8). Salvage surgery was performed in 88% of patients, of which 121 (93%) had a complete (R0) resection. Fifty-seven metastases (8.2%) were detected, and 35 (60%) were isolated without evidence of synchronous regrowths; 3-year incidence was 6.8% (95% CI, 4.1-10.2). The 3-year overall survival was 93.5% (95% CI, 90.2-96.2).

CONCLUSION

In rectal cancer patients with a cCR following neoadjuvant chemoradiotherapy, a Watch and Wait policy appears feasible and safe. Robust surveillance with early detection of regrowths allows a high rate of successful salvage surgery, without an increase in the risk of systemic disease, or adverse survival outcomes.

Long-term imaging characteristics of clinical complete responders during watch-and-wait for rectal cancer-an evaluation of over 1500 MRIs

OBJECTIVES

Rectal cancer patients with a clinical complete response after chemoradiotherapy (CRT) may be followed with a 'watch-and-wait' (W&W) approach as an alternative to surgery. MRI plays an important role in the follow-up of these patients, but basic knowledge on what to expect from the morphology of the irradiated tumour bed during follow-up is lacking, which can hamper image interpretation. The objective was to establish the spectrum of non-suspicious findings during long-term (> 2 years) follow-up in patients with a sustained clinical complete response undergoing W&W.

METHODS

A total of 1509 T2W MRIs of 164 sustained complete responders undergoing W&W were retrospectively evaluated. Morphology of the tumour bed was evaluated (2 independent readers) on the restaging MRI and on the various follow-up MRIs and classified as (a) no fibrosis, (b) minimal fibrosis, (c) full thickness fibrosis, or (d) irregular fibrosis. Any changes occurring during follow-up were documented.

RESULTS

A total of 104 patients (63%) showed minimal fibrosis, 38 (23%) full thickness fibrosis, 8 (5%) irregular fibrosis, and 14 (9%) no fibrosis. In 93% of patients, the morphology remained completely stable during follow-up; in 7%, a minor increase/decrease in fibrosis was observed. Interobserver agreement was excellent (κ 0.90).

CONCLUSIONS

Typically, the morphology as established at restaging remains completely unchanged. The majority of patients show fibrosis with the predominant pattern being a minimal fibrosis confined to the rectal wall. Complete absence of fibrosis occurs in only 1/10 cases. Once validated in independent cohorts, these findings may serve as a reference for radiologists involved in the clinical follow-up of W&W patients.

KEY POINTS

• In rectal cancer patients with a sustained complete response after chemoradiation, the rectal wall morphology as established on restaging MRI typically remains unchanged during long-term MRI follow-up. • The vast majority of complete responders show fibrosis with the predominant pattern being a minimal fibrotic remnant that remains confined to the rectal wall; complete absence of fibrosis occurs in only 10% of the cases. • Once validated in independent cohorts, the findings of this study may serve as a reference for radiologists involved in the clinical follow-up of rectal cancer patients undergoing watch-and-wait.

Neoadjuvant Radiotherapy to Facilitate Immediate Breast Reconstruction: A Systematic Review and Current Clinical Trials

BACKGROUND

Postmastectomy radiotherapy currently is used for locally advanced breast cancers that carry a high risk of locoregional failure. However, radiotherapy can have deleterious effects on immediate breast reconstruction (IBR). Neoadjuvant radiotherapy (NART) to facilitate postmastectomy IBR is an emerging new therapeutic sequence. A systematic review was undertaken to evaluate the current evidence on the feasibility and safety of this sequence.

METHODS

A comprehensive search of MEDLINE, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov from inception to 2018 was conducted, resulting in 592 records. The review included 18 retrospective and prospective studies of NART and IBR.

RESULTS

The majority of the studies used whole-breast radiotherapy with 50 Gy, conventionally fractionated, and waited 6-8 weeks before surgery. The IBR methods were varied, with both implant and autologous reconstructions. No intraoperative complications occurred, and the postoperative complication rates ranged from 3 to 36%. The partial and total flap loss rates were very low. Studies reporting cosmetic outcomes rated the majority of cases as good or excellent. The pathologic complete response rates ranged from 17 to 55%, and the locoregional recurrence rates were low (≤ 10%), with a short follow-up period. The current MD Anderson Cancer Center prospective clinical trial is described.

CONCLUSIONS

The initial results of NART and IBR demonstrate the safety of this treatment both technically and oncologically. Longer follow-up evaluation of these studies and larger prospective controlled clinical trials are needed to establish this new therapeutic sequence as a standard of care.

The impact of total neo-adjuvant treatment on nonoperative management in patients with locally advanced rectal cancer: The evaluation of 66 cases

BACKGROUND

The study aimed to assess if adherence to a total-neoadjuvant-treatment (TNT) protocol followed by observation(watch-and-wait) led to the successful nonoperative-management of low-rectal-cancer.

METHODS

In this study, patients with primary, resectable-T3-T4, N0-N1 distal-rectal-adenocarcinoma underwent-chemoradiotherapy + consolidation-chemotherapy (TNT). During the-TNT-period, endoscopy, MRI, and FDG-PET/CT were performed. We allocated patients with complete-clinical-tumor-regression, who underwent endoscopy every two months, MRI every-four-months, and PET/CT every-six-months-after-treatment, to the observation-group(OG). All other patients were referred for surgery. The OG was followed-up. The primary endpoint was local tumor-ecurrence after allocation to the OG.

RESULTS

Between 2015 and 2018, we enrolled 66-patients. Of 60-patients who were eligible to participate, 39 had complete-clinical-response(cCR) and were allocated to the OG, six underwent local-excision (LE), and 15 underwent total-mesorectal-excision (TME). The median follow-up duration was 22 (9-42) months. The local-recurrence-rate in the OG was 15.3%, and the LE and TME rates were 16.6% and 0%, respectively. All recurrence cases were salvaged through either LE or TME. The-distant-metastasis rate was 5.1%, 16.6%, and 12.5% in the OG, LE, and TME groups, respectively. The endoscopic negative-predictive-value(NPV) was 50%, and the positive-predictive-value(PPV) was 76.9% in the surgery group (LE + TME). MRI; NPV-50%, PPV-76.9%. PET/CT; NPV-100%, PPV-93.3%. Six patients(28.57%) from surgery group achieved complete pathological response (cPR).

CONCLUSION

Our results indicated a high proportion of selected-rectal-cancers with-cCR after neo-adjuvant-therapy could potentially be managed non-operatively, and major surgery may be avoided.

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios as predictive and prognostic markers in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation

Background

A standard therapy for locally advanced rectal cancer (LARC) includes fluoropyrimidine (FP)-based neoadjuvant chemoradiation (nCRT). Previous studies have inconsistently demonstrated that baseline neutrophil- and platelet-to-lymphocyte ratios (NLR and PLR) are predictive of response to nCRT or prognostic of outcomes in LARC.

Methods

We reviewed patients with LARC undergoing nCRT followed by surgery from 2005 to 2013 across 8 Canadian cancer centres. Outcome measures of interest were pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Logistic regression and Cox proportional hazard models were used to assess for associations between baseline hematologic variables and outcomes.

Results

Of 1527 identified patients, 1237 (81%) were included in the DFS/OS analysis. Median age was 62 (range 23–88), 69% were male, and 80% had performance status (PS) 0–1. Twenty-six percent had elevated NLR (≥ 4), and 66% had elevated PLR (≥ 150). Ninety-seven percent of patients received FP-based nCRT, with 96% receiving ≥44 Gy. 81% completed neoadjuvant chemotherapy and 95% completed neoadjuvant radiotherapy, with a pCR rate of 18%. After a median follow-up time of 71 months, 8% developed local recurrence, 22% developed distant recurrence and 24% died. 5-year DFS and OS were 69% (95% CI 66–72%) and 79% (95% CI 77–82%), respectively. In multivariate analyses, elevated baseline NLR and PLR were neither prognostic for DFS and OS nor predictive of pCR.

Conclusions

NLR and PLR were not found to be independently prognostic for DFS or OS and did not predict for pCR in patients with LARC undergoing nCRT followed by surgery.

Accurate outcome prediction after neo-adjuvant radio-chemotherapy for rectal cancer based on a TCP-based early regression index

•

A TCP-based early regression index (ERI_TCP) was previously introduced.

•

ERI_TCP was associated to improved survival after neo-adjuvant therapy for rectal cancer.

•

Distant-metastasis-free survival was predicted by ERI_TCP and 5-FU dose.

•

The resulting AUC (0.86) was significantly higher than models not including T ERI_TCP.

•

ERI_TCP is a promising tool for therapy personalization.

Background and purpose

An early tumor regression index (ERI_TCP) was previously introduced and found to predict pathological response after neo-adjuvant radio-chemotherapy of rectal cancer. ERI_TCP was tested as a potential biomarker in predicting long-term disease-free survival.

Materials and methods

Data of 65 patients treated with an early regression-guided adaptive boosting technique (ART) were available. Overall, loco-regional relapse-free and distant metastasis-free survival (OS, LRFS, DMFS) were considered. Patients received 41.4 Gy in 18 fractions (2.3 Gy/fr), including ART concomitant boost on the residual GTV during the last 6 fractions (3 Gy/fr, D_mean: 45.6 Gy). Chemotherapy included oxaliplatin and 5-fluorouracil (5-FU). T2-weighted MRI taken before (MRI_pre) and at half therapy (MRI_half) were available and GTVs were contoured (V_pre, V_half). The parameter ERI_TCP = −ln[(1 − (V_half/V_pre))^Vpre] was calculated for all patients. Cox regression models were assessed considering several clinical and histological variables. Cox models not including/including ERI_TCP (CONV_model and REGR_model respectively) were assessed and their discriminative power compared.

Results

At a median follow-up of 47 months, OS, LRFS and DMFS were 94%, 95% and 78%. Due to too few events, multivariable analyses focused on DMFS: the resulting CONV_model included pathological complete remission or clinical complete remission followed by surgery refusal (HR: 0.15, p = 0.07) and 5-FU dose >90% (HR: 0.29, p = 0.03) as best predictors, with AUC = 0.75. REGR_model included ERI_TCP (HR: 1.019, p < 0.0001) and 5-FU dose >90% (HR: 0.18, p = 0.005); AUC was 0.86, significantly higher than CONV_model (p = 0.05). Stratifying patients according to the best cut-off value for ERI_TCP and to 5-FU dose (> vs <90%) resulted in 47-month DMFS equal to 100%/69%/0% for patients with two/one/zero positive factors respectively (p = 0.0002). ERI_TCP was also the only variable significantly associated to OS (p = 0.01) and LRFS (p = 0.03).

Conclusion

ERI_TCP predicts long-term DMFS after radio-chemotherapy for rectal cancer: an independent impact of the 5-FU dose was also found. This result represents a first step toward application of ERI_TCP in treatment personalization: additional confirmation on independent cohorts is warranted.

Achieving a Complete Clinical Response After Neoadjuvant Chemoradiation That Does Not Require Surgical Resection: It May Take Longer Than You Think!

BACKGROUND

Patients with rectal cancer who achieve complete clinical response after neoadjuvant chemoradiation have been managed by organ-preserving strategies and acceptable long-term outcomes. Controversy still exists regarding optimal timing for the assessment of tumor response after neoadjuvant chemoradiation.

OBJECTIVE

The purpose of this study was to estimate the time interval for achieving complete clinical response using strict endoscopic and clinical criteria after a single neoadjuvant chemoradiation regimen.

DESIGN

This was a retrospective review of consecutive patients managed by 54-Gy and consolidation 5-fluorouracil-based chemotherapy. Assessment of response was performed at 10 weeks after radiation. Patients with suspected complete clinical response were offered watch-and-wait strategy and reassessment every 6 to 8 weeks until achievement of strict criteria of complete clinical response or overt residual cancer.

SETTINGS

This study was conducted at a single tertiary care center.

PATIENTS

Patients with complete clinical response who underwent a successful watch-and-wait strategy until last follow-up were eligible. Dates of radiation completion and achievement of strict endoscopic and clinical criteria (mucosal whitening, teleangiectasia, and no ulceration or irregularity) were recorded. Patients with incomplete response or with initial complete clinical response followed by local recurrence or regrowth were excluded.

MAIN OUTCOMES MEASURES

The distribution of time intervals between completion of radiation and achievement of strict complete clinical response was measured. Patients who achieved early complete clinical response (≤16 wk) were compared with late complete clinical response (>16 wk).

RESULTS

A total of 49 patients achieved complete clinical response and were successfully managed nonoperatively. A median interval of 18.7 weeks was observed for achieving strict complete clinical response. Only 38% of patients achieved complete clinical response between 10 and 16 weeks from radiation completion. Patients with earlier cT status (cT2/T3a) achieved a complete clinical response significantly earlier when compared with those patients with more advanced disease (T3b-d/4; 19 vs 26 wk; p = 0.03).

LIMITATIONS

This was a retrospective study with a small sample size.

CONCLUSIONS

Assessment at 10 to 16 weeks may detect a minority of patients who achieve complete clinical response without additional recurrence after neoadjuvant chemoradiation. Patients suspected for a complete clinical response should be considered for reassessment beyond 16 weeks before definitive management when considered for a watch and wait strategy. See Video Abstract at http://links.lww.com/DCR/A901.

Definitive radiotherapy or chemoradiotherapy for distal rectal cancer with early stage of cT1-2N0

Objectives: Patients with early-stage distal rectal cancer, if treated with radical surgery, usually suffer a poor quality of life. Definitive radiotherapy or chemoradiotherapy may be another treatment option for them. The aim of this study was to evaluate the role of definitive external beam radiotherapy or chemoradiotherapy in treating distal rectal cancer with stage cT1-2N0.

Methods: We performed a retrospective study of 231 distal rectal cancer patients who were staged as cT1-2N0 from March 2002 to March 2015. All patients were treated by definitive radiotherapy or chemoradiotherapy. Overall survival (OS), progression-free survival (PFS), and short-term efficacy were analyzed. Multivariate analysis was performed to explore clinical factors significantly associated with PFS, local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) for the whole group.

Results: For the whole group, 135 patients (58.4%) achieved clinical complete response (cCR). The 5-year OS, PFS, and LRFS were 86.19%, 83.30%, and 92.50%, respectively. Patients with cCR acquired better survival than those with non-cCR. In multivariable analysis, it revealed that clinical stage, carcinoembryonic antigen (CEA level) and concurrent chemotherapy were independent predictors of PFS.

Conclusion: Definitive radiotherapy or chemoradiotherapy may be feasible in some early-stage distal rectal cancer regarding its favorable efficacy.

Non-operative management of rectal cancer

Despite advances in technique, surgical resection of rectal cancer remains a morbid procedure that can lead a profound decrease in a patient's quality of life. A novel method of management, termed "Non-operative management" (NOM), mirrors the management of anal carcinoma. Patients undergo definitive treatment with only chemotherapy and radiation, with resection reserved only for salvage. Current data is encouraging- both in reduction in morbidity and similar, if not superior oncologic results. However, there are a number of barriers to the wide adoption of this practice. This manuscript seeks to describe the rationale and execution of NOM as well as present the current data and pitfalls of the approach.

Organ Preservation Among Patients With Clinically Node-Positive Rectal Cancer: Is It Really More Dangerous?

BACKGROUND

Select patients with complete clinical response to chemoradiation have been managed without radical surgery. The presence of radiologic evidence of nodal metastases at baseline could be a risk factor for local tumor regrowth, more advanced stage at the time of recurrence, and worse distant metastases-free survival.

OBJECTIVE

The purpose of this study was to compare the outcomes of patients with baseline node-positive and node-negative cancer after neoadjuvant chemoradiation and complete clinical response managed nonoperatively.

DESIGN

This was a retrospective review of consecutive patients with nonmetastatic distal rectal cancer undergoing neoadjuvant chemoradiation.

PATIENTS

Consecutive patients with clinical and radiologic evidence of complete clinical response at 8 to 10 weeks were managed nonoperatively and enrolled in a strict follow-up program (watch and wait). Patients with incomplete clinical response or tumor regrowth after initial complete clinical response were referred to surgery.

MAIN OUTCOMES MEASURES

Surgery-free and distant metastases-free survival were compared between patients according to nodal status at baseline.

RESULTS

A total of 117 patients with node-positive and 218 with node-negative cancer at baseline were reviewed. Overall, 62 (53.0%; node positive) and 135 (61.9%; node negative) achieved a complete clinical response and were managed nonoperatively (p = 0.13). Patients with baseline node-positive cancer had similar rates of pathologic nodal metastases at the time of recurrence. Five-year surgery-free (39.7% vs 46.8%; p = 0.2) and distant metastases-free survival (77.5% vs 80.5%; p = 0.49) were similar between baseline node-positive and node-negative patients.

LIMITATIONS

This was a retrospective study with a small sample size and possible inaccurate nodal staging.

CONCLUSIONS

Patients with rectal cancer with node-positive cancer at baseline who develop a complete clinical response after neoadjuvant chemoradiation are not at increased risk for local tumor regrowth or development of more advanced disease at the time of recurrence. These patients seem to be safe candidates for organ-preserving strategies after achieving complete clinical response. See Video Abstract at http://links.lww.com/DCR/A902.

Realizing the potential of magnetic resonance image guided radiotherapy in gynaecological and rectal cancer

CT-based radiotherapy workflow is limited by poor soft tissue definition in the pelvis and reliance on rigid registration methods. Current image-guided radiotherapy and adaptive radiotherapy models therefore have limited ability to improve clinical outcomes. The advent of MRI-guided radiotherapy solutions provides the opportunity to overcome these limitations with the potential to deliver online real-time MRI-based plan adaptation on a daily basis, a true "plan of the day." This review describes the application of MRI guided radiotherapy in two pelvic tumour sites likely to benefit from this approach.

Role of magnetic resonance imaging in organ-preserving strategies for the management of patients with rectal cancer

Total mesorectal excision has been the most effective treatment strategy adopted to reduce local recurrence rates among patients with rectal cancer. The morbidity associated with this radical surgical procedure led surgeons to challenge the standard therapy particularly when dealing with superficial lesions or good responders after neoadjuvant radiotherapy, to which radical surgery may be considered overtreatment. In this subset of patients, less invasive procedures in an organ-preserving strategy may result in good oncological and functional outcomes. In order to tailor the most appropriate treatment option, accurate baseline staging and reassessment of tumor response are relevant. MRI is the most robust tool for the precise selection of patients that are candidates for organ preservation; therefore, radiologists must be familiar with the criteria used to guide the management of these patients. The purpose of this article is to review the relevant features that radiologists should know in order to provide valuable information during the multidisciplinary discussion and ultimate management decision.

Organ Preservation in Rectal Cancer: The Patients' Perspective

Organ preservation after a clinical complete response to radiochemotherapy is currently one of the most discussed topics in the management of rectal cancer. However, the patients' perspective has only been poorly studied so far. In this multicenter study, we examined 49 patients with locally advanced rectal cancer. The willingness to participate in an organ preservation study and the acceptance of the associated aspects such as intensified radiochemotherapy protocols, the need for close follow-up examinations and local regrowth rates were assessed. Attitudes were correlated with baseline quality of life parameters and psychological scales for "fear of progression", "locus of control", "depression", and the "willingness to take risks". A total of 83% of patients would consider the deferral of surgery in case of a clinical complete response (cCR). Three monthly follow-up studies and a 25% local regrowth rate are considered acceptable by 95% and 94% respectively. While 41% would be willing to exchange cure rates for a non-operative treatment strategy, a potentially more toxic radiochemotherapy in order to increase the probability of a cCR was the aspect with the lowest acceptance (55%). Psychological factors, in particular "locus of control" and "willingness to take risks", influenced patient preferences regarding most of the assessed parameters. While in general a broad acceptance of an organ-preserving treatment can be expected, patient preferences and concerns regarding different aspects of this strategy vary widely and require specific consideration during shared decision making.

Cost-Effectiveness Analysis of Total Neoadjuvant Therapy Followed by Radical Resection Versus Conventional Therapy for Locally Advanced Rectal Cancer

BACKGROUND

Definitive surgery with total mesorectal excision is the mainstay of treatment for locally advanced rectal cancer. Multimodality therapy improves long-term survival. Current standards advise neoadjuvant chemoradiation followed by radical surgery and adjuvant chemotherapy. Nationally, compliance with adjuvant chemotherapy is only 32%. New research evaluates the effectiveness of total neoadjuvant therapy: complete chemotherapy and chemoradiation before surgery.

OBJECTIVE

The aim of this study is to determine the favored treatment for locally advanced rectal cancer by comparing the cost-effectiveness of total neoadjuvant therapy and the current standard of care.

DESIGN

Decision analytical modeling using long-term costs and 5-year disease-free survival was performed to determine the cost-effectiveness after total neoadjuvant therapy and the current standard of care. Sensitivity analysis was used to investigate the effect of uncertainty in model parameters.

SETTINGS

Centers for Medicare & Medicaid Services billing data perspective was adopted and outcomes modeled according to local and national databases and literature consensus.

PATIENTS

Adult patients with stage II or III rectal cancer were selected.

MAIN OUTCOME MEASURES

Cost-effectiveness in disease-free life-years, incremental cost-effectiveness ratio, and net monetary benefit were determined over a 5-year posttreatment period. The favored strategy was determined based on cost-effectiveness and sensitivity analyses.

RESULTS

Cost-effectiveness for total neoadjuvant therapy was 40,708 $/life-year, and, for conventional therapy, cost-effectiveness was 44,248 $/life-year. Sensitivity analysis showed that, for an estimated total neoadjuvant therapy completion rate of 90%, total neoadjuvant therapy would remain the dominant strategy for any adjuvant chemotherapy completion rate of less than 93%.

LIMITATIONS

The samples used to calculate completion rates are small, and survival probabilities are based on existing literature, local database values, and consensus estimates. The model encompasses a 5-year time period from diagnosis.

CONCLUSIONS

Cost-effectiveness analysis shows that a strategy of total neoadjuvant therapy followed by radical surgery is favored over the current standard of care for locally advanced rectal cancer. Sensitivity analysis shows that a low rate of adjuvant chemotherapy administration plays a key role in decreasing the cost-effectiveness of the current standard of care. See Video Abstract at http://links.lww.com/DCR/A942.

Organ Preservation Strategies After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

Standard use of neoadjuvant chemoradiotherapy, total mesorectal excision, and postoperative adjuvant chemotherapy in locally advanced rectal cancer has tremendously improved oncologic outcomes over the past several decades. However, these improvements come with costs of significant morbidity and poor quality of life. Along with developments in imaging techniques, clinical experience and evidence have identified a certain subgroup of patients that have exceptionally good clinical outcomes while preserving quality of life. Driven by patient demand and interest in preserving quality of life, numerous organ preservation treatment strategies for managing rectal cancer are rapidly evolving. Herein, the flow of research in organ preservation strategies and counter arguments are discussed.

Preoperative Volumetric Modulated Arc Therapy With Simultaneous Integrated Boost for Locally Advanced Distal Rectal Cancer

The aim of this study was to evaluate the safety and clinical efficacy of a combined preoperative regimen consisting of volumetric modulated arc therapy–simultaneous integrated boost and capecitabine chemotherapy for distal rectal cancer. A total of 26 patients with locally advanced distal rectal cancer were enrolled from March 2015 to May 2016. The radiation dose fractionation was 58.75 Gy/25 fractions (2.35 Gy/fraction) for rectal tumor and pelvic lymph node metastasis and 50 Gy/25 fractions for pelvic lymph node stations, accompanied with simultaneous capecitabine chemotherapy. Completion of the simultaneous chemotherapy was ensued by 1 week of rest and then another cycle of induction chemotherapy with capecitabine. A radical rectal cancer surgery was performed 6 to 8 weeks after the simultaneous chemoradiotherapy. The primary end points were the complete pathological response rate and the postoperative sphincter preservation rate. All 26 patients completed the neoadjuvant chemoradiotherapy, among which 25 received surgical treatment. The postoperative complete pathological response rate was as high as 32% (8/25), while the sphincter preservation rate was 60% (15/25), the overall tumor/node (T/N) downstaging rate was 92% (23/25), and the R0 resection rate was 100%. During the chemoradiation, the most common adverse events were grade 1 and 2; grade 3 radiodermatitis occurred in 2 cases but no occurrence of acute adverse events occurred that were grade 4 and above. After the surgery, there was one case of ureteral injury and one case of intestinal obstruction, but no perioperative deaths occurred. In conclusion, the chemoradiation regimen of preoperative volumetric modulated arc therapy-simultaneous integrated boost (VMAT-SIB_58.75Gy) and a single cycle of induction chemotherapy with capecitabine for patients with distal rectal cancer is safe and feasible with a satisfactory complete pathological response rate, sphincter preservation rate, and R0 resection rate.

Assessment of a Watch-and-Wait Strategy for Rectal Cancer in Patients With a Complete Response After Neoadjuvant Therapy

Importance

The watch-and-wait (WW) strategy aims to spare patients with rectal cancer unnecessary resection.

Objective

To analyze the outcomes of WW among patients with rectal cancer who had a clinical complete response to neoadjuvant therapy.

Design, Setting, and Participants

This retrospective case series analysis conducted at a comprehensive cancer center in New York included patients who received a diagnosis of rectal adenocarcinoma between January 1, 2006, and January 31, 2015. The median follow-up was 43 months. Data analyses were conducted from June 1, 2016, to October 1, 2018.

Exposures

Patients had a clinical complete response after completing neoadjuvant therapy and agreed to a WW strategy of active surveillance and possible salvage surgery (n = 113), or patients underwent total mesorectal excision and were found to have a pathologic complete response (pCR) at resection (n = 136).

Main Outcomes and Measures

Kaplan-Meier estimates were used for analyses of local regrowth and 5-year rates of overall survival, disease-free survival, and disease-specific survival.

Results

Compared with the 136 patients in the pCR group, the 113 patients in the WW group were older (median [range], 67.2 [32.1-90.9] vs 57.3 [25.0-87.9] years, P < .001) with cancers closer to the anal verge (median [range] height from anal verge, 5.5 [0.0-15.0] vs 7.0 [0.0-13.0] cm). All 22 local regrowths in the WW group were detected on routine surveillance and treated by salvage surgery (20 total mesorectal excisions plus 2 transanal excisions). Pelvic control after salvage surgery was maintained in 20 of 22 patients (91%). No pelvic recurrences occurred in the pCR group. Rectal preservation was achieved in 93 of 113 patients (82%) in the WW group (91 patients with no local regrowths plus 2 patients with local regrowths salvaged with transanal excision). At 5 years, overall survival was 73% (95% CI, 60%-89%) in the WW group and 94% (95% CI, 90%-99%) in the pCR group; disease-free survival was 75% (95% CI, 62%-90%) in the WW group and 92% (95% CI, 87%-98%) in the pCR group; and disease-specific survival was 90% (95% CI, 81%-99%) in the WW group and 98% (95% CI, 95%-100%) in the pCR group. A higher rate of distant metastasis was observed among patients in the WW group who had local regrowth vs those who did not have local regrowth (36% vs 1%, P < .001).

Conclusions and Relevance

A WW strategy for select rectal cancer patients who had a clinical complete response after neoadjuvant therapy resulted in excellent rectal preservation and pelvic tumor control; however, in the WW group, worse survival was noted along with a higher incidence of distant progression in patients with local regrowth vs those without local regrowth.

Oncologic Outcomes of Organ Preserving Approaches in Patients With Rectal Cancer Treated With Preoperative Chemoradiotherapy

PURPOSE

We evaluated the oncologic outcomes of organ-preserving strategies in patients with rectal cancer treated with preoperative chemoradiotherapy (PCRT).

METHODS

Between January 2008 and January 2013, 74 patients who underwent wait-and-watch (WW) (n = 42) and local excision (LE) (n = 32) were enrolled. Organ-preserving strategies were determined based on a combination of magnetic resonance imaging, sigmoidoscopy, and physical examination 4-6 weeks after completion of PCRT. The rectum sparing rate, 5-year recurrence-free survival (RFS), and overall survival (OS) were evaluated.

RESULTS

The rectum was more frequently spared in the LE (100% vs. 87.5%, P = 0.018) at last follow-up. Recurrence occurred in 9 (28.1%) WW and 7 (16.7%) LE (P = 0.169). In the WW, 7 patients had only luminal regrowth and 2 had combined lung metastasis. In the LE, 2 (4.8%) had local recurrence only, 4 patients had distant metastasis, and 1 patient had local and distant metastasis. Among 13 patients who indicated salvage surgery (WW, n = 7; LE, n = 11), all in the WW received but all of LE refused salvage surgery (P = 0.048). The 5-year OS and 5-year RFS in overall patients was 92.7% and 76.9%, respectively, and were not different between WW and LE (P = 0.725, P = 0.129).

CONCLUSION

WW and LE were comparable in terms of 5-year OS and RFS. In the LE group, salvage treatment was performed much less among indicated patients. Therefore, methods to improve the oncologic outcomes of patients indicated for salvage treatment should be considered before local excision.