Neoadjuvant capecitabine and oxaliplatin followed by synchronous chemoradiation and total mesorectal excision in magnetic resonance imaging-defined poor-risk rectal cancer

Predictive factors associated with complete pathological response after neoadjuvant treatment for rectal cancer

PURPOSE

A proportion of 10 to 30% of patients treated by chemoradiotherapy followed by total mesorectal excision surgery for a locally advanced rectal cancer can achieve a complete pathological response. We aimed to identify predictive factors associated with complete pathological response or no response and to assess the impact of each response on survival rates.

PATIENTS AND METHODS

Patients treated with long course chemoradiotherapy for locally advanced and/or node positive rectal cancer from 2010 to 2016 were retrospectively reviewed. Statistical analysis was carried out to determine predictors of tumor regression and treatment outcomes.

RESULTS

Records were available on 70 patients. In the univariate analysis, clinical factors associated with complete tumor response were tumor mobility in digital rectal examination (P=0.047), a limited parietal invasion (P=0.001), clinically negative lymph node (P<0.001) and a circumferential extent greater than 50% (P=0.001). On the other hand, a T4 classification and an endoscopic tumor size greater than 6cm were associated with no response to treatment (P=0.049 and P=0.017 respectively). On multivariate analysis, T2 clinical classification and N0 statement before treatment were independent predictive factors of pathologic complete response (P<0.001 and P=0.001) and a delayed surgery after 12 weeks was associated with no response to treatment (P=0.001).

CONCLUSION

The identification of predictive factors of histological response may help clinicians to predict the prognosis and to propose organ preservation for good responders.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Total Neoadjuvant Therapy vs Standard Therapy in Locally Advanced Rectal Cancer: A Systematic Review and Meta-analysis

Importance

Standard therapy for locally advanced rectal cancer includes concurrent chemoradiotherapy followed by surgery and adjuvant chemotherapy (CRT plus A). An alternative strategy known as total neoadjuvant therapy (TNT) involves administration of CRT plus neoadjuvant chemotherapy before surgery with the goal of delivering uninterrupted systemic therapy to eradicate micrometastases. A comparison of these 2 approaches has not been systematically reviewed previously.

Objective

To determine the differences in rates of pathologic complete response (PCR), disease-free and overall survival, sphincter-preserving surgery, and ileostomy between patients receiving TNT vs standard CRT plus A.

Data Sources

MEDLINE (via PubMed) and Embase (via OVID) were searched from inception through July 1, 2020, for the following terms: anal/anorectal neoplasms OR anal/anorectal cancer AND total neoadjuvant treatment OR total neoadjuvant therapy. Only studies in English were included.

Study Selection

Randomized clinical trials or prospective/retrospective cohort studies comparing outcomes in patients with locally advanced rectal cancer who received TNT vs CRT plus A.

Data Extraction and Synthesis

Data regarding the first author, publication year, location, sample size, and rates of PCR, sphincter-preserving surgery, ileostomy, and disease-free and overall survival were extracted using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and pooled using a random-effects model.

Main Outcomes and Measures

Rates of PCR, sphincter-preserving surgery, ileostomy, and disease-free and overall survival.

Results

After reviewing 2165 reports, 7 unique studies including a total of 2416 unique patients, of whom 1206 received TNT, were selected. The median age for the patients receiving TNT ranged from 57 to 69 years, with 58% to 73% being male. The pooled prevalence of PCR was 29.9% (range, 17.2%-38.5%) in the TNT group and 14.9% (range, 4.2%-21.3%) in the CRT plus A group. Total neoadjuvant therapy was associated with a higher chance of achieving a PCR (odds ratio [OR], 2.44; 95% CI, 1.99-2.98). No statistically significant difference in the proportion of sphincter-preserving surgery (OR, 1.06; 95% CI, 0.73-1.54) or ileostomy (OR, 1.05; 95% CI, 0.76-1.46) between recipients of TNT and CRT plus A was observed. Only 3 studies presented data on disease-free survival, and pooled analysis showed significantly higher odds of improved disease-free survival in patients who received TNT (OR, 2.07; 95% CI, 1.20-3.56; I2 = 49%). Data on overall survival were not consistently reported.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that TNT is a promising strategy in locally advanced rectal cancer, with superior rates of PCR compared with standard therapy. However, the long-term effect on disease recurrence and overall survival needs to be explored in future studies.

Recent advances in (chemo-)radiation therapy for rectal cancer: a comprehensive review

The role of radiation therapy in the treatment of (colo)-rectal cancer has changed dramatically over the past decades. Introduced with the aim of reducing the high rates of local recurrences after conventional surgery, major developments in imaging, surgical technique, systemic therapy and radiation delivery have now created a much more complex environment leading to a more personalized approach. Functional aspects including reduction of acute or late treatment-related side effects, sphincter or even organ-preservation and the unsolved problem of still high distant failure rates have become more important while local recurrence rates can be kept low in the vast majority of patients. This review summarizes the actual role of radiation therapy in different subgroups of patients with rectal cancer, including the current standard approach in different subgroups as well as recent developments focusing on neoadjuvant treatment intensification and/or non-operative treatment approaches aiming at organ-preservation.

Short-course radiation followed by mFOLFOX-6 plus avelumab for locally-advanced rectal adenocarcinoma

BACKGROUND

Current standard practice for locally advanced rectal cancer (LARC) entails a multidisciplinary approach that includes preoperative chemoradiotherapy, followed by total mesorectal excision, and then adjuvant chemotherapy. The latter has been accompanied by low compliance rates and no survival benefit in phase III randomized trials, so the strategy of administering neoadjuvant, rather than adjuvant, chemotherapy has been adapted by many trials, with improvement in pathologic complete response. Induction chemotherapy with oxaliplatin has been shown to have increased efficacy in rectal cancer, while short-course radiation therapy with consolidation chemotherapy increased short-term overall survival rate and decreased toxicity levels, making it cheaper and more convenient than long-course radiation therapy. This led to recognition of total neoadjuvant therapy as a valid treatment approach in many guidelines despite limited available survival data. With the upregulation (PDL-1) expression in rectal tumors after radiotherapy and the increased use of in malignant melanoma, the novel approach of combining immunotherapy with chemotherapy after radiation may have a role in further increasing pCR and improving overall outcomes in rectal cancer.

METHODS

The study is an open label single arm multi- center phase II trial. Forty-four recruited LARC patients will receive 5Gy x 5fractions of SCRT, followed by 6 cycles of mFOLFOX-6 plus avelumab, before TME is performed. The hypothesis is that the addition of avelumab to mFOLFOX-6, administered following SCRT, will improve pCR and overall outcomes. The primary outcome measure is the proportion of patients who achieve a pCR, defined as no viable tumor cells on the excised specimen. Secondary objectives are to evaluate 3-year progression-free survival, tumor response to treatment (tumor regression grades 0 & 1), density of tumor-infiltrating lymphocytes, correlation of baseline Immunoscore with pCR rates and changes in PD-L1 expression.

DISCUSSION

Recent studies show an increase in PD-L1 expression and density of CD8+ TILs after CRT in rectal cancer patients, implying a potential role for combinatory strategies using PD-L1- and programmed-death- 1 inhibiting drugs. We aim through this study to evaluate pCR following SCRT, followed by mFOLFOX-6 with avelumab, and then TME procedure in patients with LARC.

TRIAL REGISTRATION

Trial Registration Number and Date of Registration: ClinicalTrials.gov NCT03503630, April 20, 2018.

Neoadjuvant Chemotherapy without Radiation in Colorectal Cancer

In colon cancer, primary surgery followed by postoperative chemotherapy represents the standard of care. In rectal cancer, the standard of care is preoperative radiotherapy or chemoradiation, which significantly reduces local recurrence but has no impact on subsequent metastatic disease or overall survival. The administration of neoadjuvant chemotherapy (NACT) before surgery can increase the chance of a curative resection and improves long-term outcomes in patients with liver metastases. Hence, NACT is being explored in both primary rectal and colon cancers as an alternative strategy to shrink the tumor, facilitate a curative resection, and simultaneously counter the risk of metastases. Yet, this lack of clarity regarding the precise aims of NACT (downstaging, maximizing response, or improving survival) is hindering progress. The appropriate cytotoxic agents, the optimal regimen, the number of cycles, or duration of NACT prior to surgery or in the postoperative setting remains undefined. Several potential strategies for integrating NACT are discussed with their advantages and disadvantages.

Pre-Existing Tumoral B Cell Infiltration and Impaired Genome Maintenance Correlate with Response to Chemoradiotherapy in Locally Advanced Rectal Cancer

Locally advanced rectal cancer (LARC) remains a medical challenge. Reliable biomarkers to predict which patients will significantly respond to neoadjuvant chemoradiotherapy (nCRT) have not been identified. We evaluated baseline genomic and transcriptomic features to detect differences that may help predict response to nCRT. Eligible LARC patients received nCRT (3D-LCRT 50.4 Gy plus capecitabine 825 mg/m2/bid), preceded by three cycles of CAPOX in high systemic-relapse risk tumors, and subsequent surgery. Frozen tumor biopsies at diagnosis were sequenced using a colorectal cancer panel. Transcriptomic data was used for pathway and cell deconvolution inferential algorithms, coupled with immunohistochemical validation. Clinical and molecular data were analyzed according to nCRT outcome. Pathways related to DNA repair and proliferation (p < 0.005), and co-occurrence of RAS and TP53 mutations (p = 0.001) were associated with poor response. Enrichment of expression signatures related to enhanced immune response, particularly B cells and interferon signaling (p < 0.005), was detected in good responders. Immunohistochemical analysis of CD20+ cells validated the association of good response with B cell infiltration (p = 0.047). Findings indicate that the presence of B cells is associated with successful tumor regression following nCRT in LARC. The prevalence of simultaneous RAS and TP53 mutations along with a proficient DNA repair system that may counteract chemoradio-induced DNA damage was associated with poor response.

Immune-Modulating Effects of Conventional Therapies in Colorectal Cancer

Biological heterogeneity and low inherent immunogenicity are two features that greatly impact therapeutic management and outcome in colorectal cancer. Despite high local control rates, systemic tumor dissemination remains the main cause of treatment failure and stresses the need for new developments in combined-modality approaches. While the role of adaptive immune responses in a small subgroup of colorectal tumors with inherent immunogenicity is indisputable, the challenge remains in identifying the optimal synergy between conventional treatment modalities and immune therapy for the majority of the less immunogenic cases. In this context, cytotoxic agents such as radiation and certain chemotherapeutics can be utilized to enhance the immunogenicity of an otherwise immunologically silent disease and enable responsiveness to immune therapy. In this review, we explore the immunological characteristics of colorectal cancer, the effects that standard-of-care treatments have on the immune system, and the opportunities arising from combining immune checkpoint-blocking therapy with immune-modulating conventional treatments.

Neo-adjuvant chemotherapy alone for the locally advanced rectal cancer: a systematic review

Neo-adjuvant chemoradiation (NA-CRT) is the standard of management for the locally advanced rectal cancer (LARC), achieving very low rates of local recurrence (LR). However, NA-CRT fails to control distant recurrence and improve survival, whilst it is associated with increased postoperative morbidity and increased acute and late toxicity. In recent years, neo-adjuvant chemotherapy (NACTx) appears in the literature as an alternative to NA-CRT in patients with LARC. In the present study, the authors review all current evidence on the specific subject. Following a systematic search of the literature, 25 studies were identified reporting on short- or long-term outcomes of NACTx for LARC. Seventeen studies were prospective or retrospective series, and 8 comparative. Of the comparative studies, one was a randomized control trial (RCT) comparing NACTx to NA-CRT and to the combination of NACTx/NA-CRT, and another a non-randomized study comparing NACTx to NA-CRT. Chemotherapeutic regimens were 5-fluoropyrimidine and oxaliplatin based. In some of them, irinotecan or/and bevacizumab was added. A pooled analysis showed that NACTx is associated with a mean anastomotic leak rate of 6.8%. In the RCT, postoperative morbidity and overall toxicity was significantly less in the NACTx group. Mean T downstaging (ypStage 0-I) was 49.6%, mean N downstaging 69.6% and mean pathologic complete response (pCR) 10.7%. The RCT showed an inferior pCR rate after NACTx than after NA-CRT, but similar rates of T downstaging. Mean LR was 8.6% and mean distant recurrence 17.2%. Satisfactory survival rates are reported by several studies. NACTx seems to be an alternative to NA-CRT for patients with LARC, associated with low anastomotic leak, adequate tumour downstaging, low LR and rather high survival rates. Further data deriving from high-quality studies are necessary to assess safety and efficacy of NACTx as a substitute to NA-CRT, for at least a subset of patients with LARC.

Recommendations for the use of radiation therapy in managing patients with gastrointestinal malignancies in the era of COVID-19

As of April 6, 2020, there are over 1,200,000 reported cases and 70,000 deaths worldwide due to COVID-19, the disease caused by the SARS-CoV-2 virus, and these numbers rise exponentially by the day [1]. According to the Centers for Disease Control (CDC), the most effective means of minimizing the spread of the virus is through reducing interactions between individuals [2]. We performed a review of the literature, as well as national and international treatment guidelines, seeking data in support of the RADS principle (Remote visits, Avoid radiation, Defer radiation, Shorten radiation) [3] as it applies to gastrointestinal cancers. The purpose of the present work is to guide radiation oncologists managing patients with gastrointestinal cancers during the COVID-19 crisis in order to maintain the safety of our patients, while minimizing the impact of the pandemic on cancer outcomes.

NCCN Guidelines Insights: Rectal Cancer, Version 6.2020

The NCCN Guidelines for Rectal Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with rectal cancer. These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines. These updates include clarifying the definition of rectum and differentiating the rectum from the sigmoid colon; the total neoadjuvant therapy approach for localized rectal cancer; and biomarker-targeted therapy for metastatic colorectal cancer, with a focus on new treatment options for patients with BRAF V600E- or HER2 amplification-positive disease.

Improved Outcomes for Responders After Treatment with Induction Chemotherapy and Chemo(re)irradiation for Locally Recurrent Rectal Cancer

BACKGROUND

Despite improvements in the multimodality treatment for patients with locally recurrent rectal cancer (LRRC), oncological outcomes remain poor. This study evaluated the effect of induction chemotherapy and subsequent chemo(re)irradiation on the pathologic response and the rate of resections with clear margins (R0 resection) in relation to long-term oncological outcomes.

METHODS

All consecutive patients with LRRC treated in the Catharina Hospital Eindhoven who underwent a resection after treatment with induction chemotherapy and subsequent chemo(re)irradiation between January 2010 and December 2018 were retrospectively reviewed. Induction chemotherapy consisted of CAPOX/FOLFOX. Endpoints were pathologic response, resection margin and overall survival (OS), disease free survival (DFS), local recurrence free survival (LRFS), and metastasis free survival (MFS).

RESULTS

A pathologic complete response was observed in 22 patients (17%), a "good" response (Mandard 2-3) in 74 patients (56%), and a "poor" response (Mandard 4-5) in 36 patients (27%). An R0 resection was obtained in 83 patients (63%). The degree of pathologic response was linearly correlated with the R0 resection rate (p = 0.026). In patients without synchronous metastases, pathologic response was an independent predictor for LRFS, MFS, and DFS (p = 0.004, p = 0.003, and p = 0.024, respectively), whereas R0 resection was an independent predictor for LRFS and OS (p = 0.020 and p = 0.028, respectively).

CONCLUSIONS

Induction chemotherapy in addition to neoadjuvant chemo(re)irradiation is a promising treatment strategy for patients with LRRC with high pathologic response rates that translate into improved oncological outcomes, especially when an R0 resection has been achieved.

Immunogenic cell death by neoadjuvant oxaliplatin and radiation protects against metastatic failure in high-risk rectal cancer

OBJECTIVE

High rates of systemic failure in locally advanced rectal cancer call for a rational use of conventional therapies to foster tumor-defeating immunity.

METHODS

We analyzed the high-mobility group box-1 (HMGB1) protein, a measure of immunogenic cell death (ICD), in plasma sampled from 50 patients at the time of diagnosis and following 4 weeks of induction chemotherapy and 5 weeks of sequential chemoradiotherapy, both neoadjuvant modalities containing oxaliplatin. The patients had the residual tumor resected and were followed for long-term outcome.

RESULTS

Patients who met the main study end point-freedom from distant recurrence-showed a significant rise in HMGB1 during the induction chemotherapy and consolidation over the chemoradiotherapy. The higher the ICD increase, the lower was the metastatic failure risk (hazard ratio 0.26, 95% confidence interval 0.11-0.62, P = 0.002). However, patients who received the full-planned oxaliplatin dose of the chemoradiotherapy regimen had poorer metastasis-free survival (P = 0.020) than those who had the oxaliplatin dose reduced to avert breach of the radiation delivery, which is critical to maintain efficient tumor cell kill and in the present case, probably also protected the ongoing radiation-dependent ICD response from systemic oxaliplatin toxicity.

CONCLUSION

The findings indicated that full-dose induction oxaliplatin followed by an adapted oxaliplatin dose that was compliant with full-intensity radiation caused induction and maintenance of ICD and as a result, durable disease-free outcome for a patient population prone to metastatic progression.

Total neoadjuvant treatment of locally advanced rectal cancer with high risk factors in Slovenia

Background In the light of a high rate of distant recurrence and poor compliance of adjuvant chemotherapy in high risk rectal cancer patients the total neoadjuvant treatment was logical approach to gaining acceptance. We aimed to evaluate toxicity and efficiency of this treatment in patients with rectal cancer and high risk factors for local or distant recurrence. Patients and methods Patients with rectal cancer stage II and III and with at least one high risk factor: T4, presence of extramural vein invasion (EMVI), positive extramesorectal lymph nodes or mesorectal fascia (MRF) involvement were treated with four cycles of induction CAPOX/FOLFOX, followed by capecitabine-based radiochemotherapy (CRT) and two consolidation cycles of CAPOX/FOLFOX before the operation. Surgery was scheduled 8-10 weeks after completition of CRT. Results From November 2016 to July 2018 66 patients were evaluable. All patients had stage III disease, 24 (36.4%) had T4 tumors, in 46 (69.7%) EMVI was present and in 47 (71.2%) MRF was involved. After induction chemotherapy, which was completed by 61 (92.4%) of patients, radiologic downstaging of T, N, stage, absence of EMVI or MRF involvement was observed in 42.4%, 62.1%, 36.4%, 69.7% and 68.2%, respectively. All patients completed radiation and 54 (81.8%) patients received both cycles of consolidation chemotherapy. Grade 3 adverse events of neoadjuvant treatment was observed in 4 (6%) patients. Five patients rejected surgery, 3 of them with radiologic complete clinical remissions. One patient did not have definitive surgery of primary tumor due to unexpected cardiac arrest few days after sigmoid colostomy formation. Among 60 operated patients pathological complete response rate was 23.3%, the rate of near complete response was 20% and in 96.7% radical resection was achieved. Pathological T, N and stage downstaging was 65%, 96.7% and 83.4%, respectively. Grade ≥ 3 perioperative complications were anastomotic leakage in 3, pelvic abscess in 1 and paralytic ileus in 2 patients. The rate of pathologic complete response (pCR) in patients irradiated with 3D conformal technique was 12.1% while with IMRT and VMAT it was 37% (p < 0.05). Hypofractionation with larger dose per fraction and simultaneous integrated boost used in the latest two was the only factor associated with pCR. ConclusionsTotal neoadjuvant treatment of high risk rectal cancer is well tolerated and highly effective with excellent tumor and node regression rate and with low toxicity rate. Longer follow up will show if this strategy will improve distant disease control and survival.

Neoadjuvant volumetric modulated arc radiochemotherapy with a simultaneous integrated boost technique compared to standard chemoradiation for locally advanced rectal cancer

Background/aim

The present study aimed to examine whether the combination of neoadjuvant volumetric modulated arc radiotherapy (VMAT) using simultaneous integrated boost (SIB-VMAT) techniques and chemotherapy with capecitabine is associated with better clinical and dosimetric outcomes compared to the standard treatment.

Materials and methods

The study included 59 patients with cT2–T4 rectal cancer. In the standard arm, patients (n = 37) were treated preoperatively with image-guided VMAT plus capecitabine. In the SIB arm, patients (n = 22) were treated with the SIB-VMAT technique plus capecitabine. All patients underwent radical surgical resection after neoadjuvant radiochemotherapy.

Results

In the standard arm, cT0N0 was reached in 12 patients (32.4%), primary tumor clinical downstaging was observed in 22 patients (59.5%), and disease stability was achieved in 3 patients (8.1%). In the SIB arm, cT0N0 was reached in 15 patients (68.2%), primary tumor clinical downstaging was observed in 6 patients (27.3%), and disease stability was achieved in 1 patient (4.5%) (P = 0.028). Complete pathological response was observed in 11 patients (29.7%) in the standard arm and in 13 patients (59.1%) in the SIB arm (P = 0.026). In the SIB arm mild diarrhea appeared in 59.1%, moderate in 40.9%, and severe in 0% of the cases. In the standard arm mild, moderate, and severe diarrhea rates were in 54.1%, 43.2%, and 2.7%, respectively. In the SIB arm mild, moderate, and severe cystitis appeared in 63.6%, 22.7%, and 13.6%, while in the standard group mild cystitis developed in 67.6%, moderate in 24.3%, and severe in 8.1%. Mild, moderate, and severe radiation dermatitis rates were 45.5%, 45.5%, and 9.1% in the SIB group and 40.5%, 48.6%, and 10.8% in the standard group, respectively.

Conclusion

The SIB-VMAT technique is effective and safe for irradiating locally advanced rectal cancer. Its effectiveness is expressed in higher clinical and pathological complete response rates and safety with the same rates of acute toxicity.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.

Efficacy and Feasibility of Adding Induction Chemotherapy to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Phase II Clinical Trial

PURPOSE

Currently, neoadjuvant chemoradiation (CRT) followed by total mesorectal resection is considered the standard of care for treating locally advanced rectal cancer. This study aimed to investigate the efficacy and feasibility of adding induction chemotherapy to neoadjuvant CRT in locally advanced rectal cancer.

METHODS

This phase-II clinical trial included 54 patients with newly diagnosed, locally advanced (clinical T3-4 and/or N1-2, M0) rectal cancer. All patients were treated with 3 cycles of preoperative chemotherapy using the XELOX (capecitabine + oxaliplatin) regimen before and after a concurrent standard long course of CRT (45-50.4 Gy) followed by standard radical surgery. Pathologic complete response (PCR) rate and toxicity were the primary and secondary endpoints, respectively.

RESULTS

The study participants included 37 males and 17 females, with a median age of 59 years (range, 20-80 years). Twenty-nine patients (54%) had clinical stage-II disease, and 25 patients (46%) had clinical stage-III disease. Larger tumor size (P = 0.006) and distal rectal location (P = 0.009) showed lower PCR compared to smaller tumor size and upper rectal location. Pathologic examinations showed significant tumor regression (6.1 ± 2.7 cm vs. 1.9 ± 1.8 cm, P < 0.001) with 10 PCRs (18.5%) compared to before the intervention. The surgical margin was free of cancer in 52 patients (96.3%). Treatment-related toxicities were easily tolerated, and all patients completed their planned treatment without interruption. Grade III and IV toxicities were infrequent.

CONCLUSION

The addition of induction chemotherapy to neoadjuvant CRT is an effective and well-tolerated treatment approach in patients with rectal cancer.

Use of Neoadjuvant Chemotherapy in the Treatment of Locally Advanced Rectal Cancer

BACKGROUND

Current treatment for locally advanced rectal cancer includes neoadjuvant chemoradiation followed by surgery and adjuvant chemotherapy. With neoadjuvant chemotherapy (NC), both chemoradiation and chemotherapy are given in the neoadjuvant setting. This study aims to assess patterns of NC utilization and differences in treatment response compared with standard treatment at our institution.

MATERIALS AND METHODS

We performed a retrospective review of patients treated for stage II-III rectal cancer at our institution between 2008 and 2018, examining patient demographics, tumor characteristics, and treatment modality. The primary outcome of interest was complete response (CR) to treatment, including both pathologic and clinical CR.

RESULTS

Of 184 patients, 134 (72.8%) received standard therapy, and 50 (27.2%) received NC. In the standard treatment group, 70.1% were node positive, and 9.0% had T4-disease, compared with 92.0% and 26.0% in the NC group, respectively (both P < 0.01). NC utilization increased over time, with 3.4% of patients receiving NC between 2008 and 2012, compared with 48.5% in 2013-2018 (P < 0.01). CR was achieved in 19.4% versus 34.0% (P < 0.01) of patients in standard versus NC groups. With multivariate analysis, NC (odds ratio = 3.02 [95% confidence interval 1.37-6.67], P = 0.01) was associated with increased likelihood of achieving CR, whereas higher T-stage was associated with decreased likelihood of CR (for cT4, odds ratio = 0.06 [95% confidence interval 0.01-0.56], P = 0.01).

CONCLUSIONS

Use of NC was increasingly used at our institution from 2008 to 2018. Patients who received NC achieved higher rates of CR compared with those undergoing standard therapy, despite having more advanced disease. These data support trends from other institutions and provides rationale for further study regarding use of NC for locally advanced rectal cancer.

Prognostic factors and patterns of failure after surgery for T4 rectal cancer in the beyond total mesorectal excision era

BACKGROUND

Despite advances in the rates of total mesorectal excision (TME) for rectal cancer surgery, decreased local recurrence rates and increased 5-year survival, there still exists large variation in the quality of treatment received. Up to 30 per cent of rectal cancers are locally advanced at presentation and approximately 5-10 per cent still breach the mesorectal plane and invade adjacent structures despite neoadjuvant therapy. With the evolution of extended resections for rectal cancers beyond the TME plane, proponents advocate that these resections should be performed only in specialist centres. The aim was to assess the prognostic factors and patterns of failure after beyond TME surgery for T4 rectal cancers.

METHODS

Data were collected from prospective databases at three high-volume institutions specializing in beyond TME surgery for T4 rectal cancers between 1990 and 2013. The primary outcome measures were overall survival, local recurrence and patterns of first failure.

RESULTS

Three hundred and sixty patients were identified. The negative resection margin (R0) rate was 82·8 per cent (298 patients) and the local recurrence rate was 12·5 per cent (45 patients). The type of surgical procedure (Hartmann's: hazard ratio (HR) 4·49, 95 per cent c.i. 1·99 to 10·14; P = 0·002) and lymphovascular invasion (HR 2·02, 1·08 to 3·77; P = 0·032) were independent predictors of local recurrence. The 5-year overall survival rate for all patients was 61 (95 per cent c.i. 55 to 67) per cent. The 5-year cumulative incidence of first failure was 8 per cent for local recurrence, 6 per cent for local and distant disease, and 18 per cent for distant disease.

CONCLUSION

This study has demonstrated that a coordinated approach in specialist centres for beyond TME surgery can offer good oncological and long-term survival in patients with T4 rectal cancers.

Neoadjuvant Chemotherapy With mFOLFOXIRI Without Routine Use of Radiotherapy for Locally Advanced Rectal Cancer

INTRODUCTION

Although neoadjuvant chemo-radiotherapy (CRT) achieves low local recurrence rates in locally advanced rectal cancer (LARC), it raises a lot of concerns about long-term anal and sexual functions. We explored the efficacy of preoperative chemotherapy with mFOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin, and irinotecan) in patients with LARC.

PATIENTS AND METHODS

Patients with LARC evaluated by pelvic magnetic resonance imaging (MRI) were enrolled in this trial. All received 4 to 6 cycles of mFOLFOXIRI. MRI was performed to assess clinical response after chemotherapy. Patients with mesorectal fascia-positive or ycT4a/b after re-evaluation would receive radiation before surgery, whereas responders would have immediate total mesorectal excision (TME). Adjuvant chemotherapy with mFOLFOX6 (folinic acid, 5-fluorouracil, and oxaliplatin) was recommended. The primary endpoint was the proportion of tumor downstaging to ypT_0-2N₀M₀. The secondary endpoints were pathologic complete response rate (pCR), 3-year disease-free survival rate, and safety.

RESULTS

Overall, 106 patients were enrolled and received neoadjuvant mFOLFOXIRI chemotherapy. A total of 103 participants underwent TME surgery. Among 103 patients who completed at least 4 cycles of preoperative chemotherapy, 2 received short-term radiation before TME, and 12 underwent long-term CRT after MRI evaluation. The pCR rate was 20.4%, and the tumor downstaging rate was 42.7%. Among patients without preoperative long-term radiotherapy, the pCR rate and tumor downstaging rate were 17.4% and 41.3%, respectively. Among the per-protocol population, the tumor downstaging rate was 48.1%, and the pCR rate was 20.3%. The chemotherapy-related toxicity was well-tolerated.

CONCLUSION

Neoadjuvant chemotherapy with mFOLFOXIRI and selective radiation does not seem to compromise outcomes in LARC. It could be a reasonable alternative to CRT in previously untreated patients with LARC.

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.

Induction Chemotherapy Reduces Patient-reported Toxicities During Neoadjuvant Chemoradiation with Intensity Modulated Radiotherapy for Rectal Cancer

BACKGROUND

Initial treatment with either neoadjuvant chemoradiation (CRT) or induction FOLFOX (5-Fluorouracil, leucovorin, and oxaliplatin) chemotherapy followed by CRT is considered standard treatment for locally advanced rectal cancer. We compared patient-reported outcomes (PRO) during CRT in patients who had received induction chemotherapy versus those who did not.

PATIENTS AND METHODS

We reviewed records of patients with locally advanced rectal cancer who were treated with CRT between September 2009 and October 2014, and who had completed ≥ 4 PRO assessments during treatment. Clinician- and patient-reported toxicities were collected each week during treatment. We fit binomial generalized linear models to maximum toxicity scores across all patients' visits.

RESULTS

Of 123 patients with ≥ 4 PRO assessments, 87 (71%) patients reported a clinically meaningful PRO score of 3 or higher for diarrhea, and 91 (74%) patients reported a PRO score of ≥ 3 for urgency, during 1 or more weeks of treatment, corresponding to 'very frequent' or worse. Of 116 patients who had also completed ≥ 4 clinician-reported assessments for descriptive analysis, clinically significant diarrhea (Common Terminology Criteria for Adverse Events grade ≥ 2) was reported in 9% of patients, and grade 2 proctitis and cystitis were reported in 20% and 4%, respectively. Eighty-four (68%) patients had undergone induction chemotherapy prior to CRT. Patients who received induction chemotherapy had 68% lower odds of experiencing significant urgency (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.11-0.95; P = .04), 76% lower odds of bleeding (OR, 0.24; 95% CI, 0.1-0.62; P < .01), and 75% lower odds of tenesmus (OR, 0.25; 95% CI, 0.11-0.6; P < .01) versus those treated with upfront CRT.

CONCLUSION

Based on PROs, a high proportion of patients experienced clinically significant symptoms during pelvic CRT, with diarrhea and urgency being most commonly reported. This appears to be under-reported on clinician-reported assessments. Delivery of induction chemotherapy was associated with lower odds of experiencing urgency, bleeding, and tenesmus on PROs during subsequent CRT, with no significant impact on diarrhea and rectal pain.

Trends in combined radio-chemotherapy for locally advanced rectal cancer: a survey among radiation oncology centers of Sicily region on behalf of AIRO

AIM

To conduct a survey among Sicilian centers of radiation oncology belonging to Associazione Italiana di Radioterapia ed Oncologia Clinica (AIRO), to record the different methods of integration of radio-chemotherapy both in neoadjuvant and adjuvant settings, to evaluate surgical procedures in relation to the sphincter preservation and to report the different toxicity profiles of the treatment strategies.

METHODS

A questionnaire was sent at the end of 2017 to all the radiation oncology centers of Sicily region in order to collect the data from individual centers and the treatment characteristics retrospectively over the previous 5 years, from 2012 to 2016. The required data were collected from 13 centers out of 17 which, in relation to the single catchment areas, correspond to approximately 85% of the Sicilian population. The requested data concerned the type of integrated treatment (neoadjuvant vs adjuvant vs radical), combination with chemotherapy (induction, concomitant, adjuvant), type of surgical intervention (sphincter-saving vs abdomino-perineal resection), disease stage, schedule and radiotherapy technique adopted, as well as toxicity detected over the treatment period.

RESULTS

A total of 784 pts (M/F: 509/275) were treated between 2012 and 2016, with a median age of 67 years (range 25-92). The majority of patients was treated in the neoadjuvant phase (62% of the total) compared to the adjuvant phase (31%) and to those treated radically (7%). Twenty-five percent of patients did not receive combination chemotherapy mainly for cardiovascular problems. Chemotherapy used concomitantly to radiotherapy was single-agent capecitabine (73% of patients) or 5-fluorouracil (27%). The use of chemotherapy alone before concomitant treatment is more common for patients treated in the adjuvant phase (64% of this subgroup), while 14% of patients treated in the neoadjuvant phase received induction chemotherapy before the concomitant phase; in both cases of chemotherapy alone, the majority of patients (91%) received oxaliplatin-based protocols (FOLFOX/XELOX/CAPOX). Few patients (3%) received chemotherapy alone after the concomitant phase. Information on the surgical treatment received is available for 88% of the sample. Of these, 93% received a surgical treatment. The overall rate of sphincter-saving surgery (anterior resection) was 72%, but the contribution of neoadjuvant treatment allowed to reach a rate of 83% in this subgroup (against 65% found in the subgroup of patients treated in adjuvant phase). Traditional radiotherapy schedule (45-50 Gy in 25-28 fractions) was used in 90% of patients, of which an intensified treatment in neoadjuvant phase (45 Gy + boost of 9-10 Gy) was used in 11% of patients. A short-course regimen (25 Gy in 5 fraction) in neoadjuvant setting was opted rarely (7%). Three-dimensional conformal technique was preferred over intensity-modulated ones (73% vs 27%). Toxicity was mainly of grade I-II CTCAE (skin 23%, gastrointestinal 39%, genitourinary 14%) compared to grade III (gastrointestinal 4%, genitourinary and hematological < 1%). Interestingly, the toxicity rates were significantly higher in the adjuvant group compared to the neoadjuvant (GI: 58% vs 31%, GU: 21% vs 10%).

CONCLUSION

The present survey shows that in the Sicily region integrated therapies for rectal cancer have allowed a neoadjuvant approach in the majority of patients, thus resulting in a greater use of sphincter conservative surgery. The toxicity has also been reported to be significantly less in this treatment setting.

Maintenance avelumab versus continuation of first-line chemotherapy in gastric cancer: JAVELIN Gastric 100 study design

Avelumab is a human anti-PD-L1 IgG1 monoclonal antibody that has shown antitumor activity in early phase studies in advanced/metastatic gastric/gastroesophageal junction cancer, including as first-line maintenance therapy. Here, we describe the design of JAVELIN Gastric 100 (NCT02625610), an open-label, Phase III trial. A total of 499 patients with locally advanced/metastatic HER2- gastric/gastroesophageal junction cancer adenocarcinoma, who had achieved at least stable disease following 12 weeks of first-line oxaliplatin/fluoropyrimidine chemotherapy, have been randomized 1:1 to receive avelumab maintenance therapy or continue chemotherapy. The primary objective is to demonstrate superior overall survival in all randomized patients or in the PD-L1+ population. Secondary objectives are to demonstrate superiority for progression-free survival and objective response rate, compare quality of life measures, and determine safety.

Exercise interventions for people undergoing multimodal cancer treatment that includes surgery

BACKGROUND

People undergoing multimodal cancer treatment are at an increased risk of adverse events. Physical fitness significantly reduces following cancer treatment, which is related to poor postoperative outcome. Exercise training can stimulate skeletal muscle adaptations, such as increased mitochondrial content and improved oxygen uptake capacity may contribute to improved physical fitness.

OBJECTIVES

To determine the effects of exercise interventions for people undergoing multimodal treatment for cancer, including surgery, on physical fitness, safety, health-related quality of life (HRQoL), fatigue, and postoperative outcomes.

SEARCH METHODS

We searched electronic databases of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, SPORTDiscus, and trial registries up to October 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared the effects of exercise training with usual care, on physical fitness, safety, HRQoL, fatigue, and postoperative outcomes in people undergoing multimodal cancer treatment, including surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, performed the data extraction, assessed the risk of bias, and rated the quality of the studies using Grading of Recommendation Assessment, Development, and Evaluation (GRADE) criteria. We pooled data for meta-analyses, where possible, and reported these as mean differences using the random-effects model.

MAIN RESULTS

Eleven RCTs were identified involving 1067 participants; 568 were randomly allocated to an exercise intervention and 499 to a usual care control group. The majority of participants received treatment for breast cancer (73%). Due to the nature of the intervention, it was not possible to blind the participants or personnel delivering the intervention. The risk of detection bias was either high or unclear in some cases, whilst most other domains were rated as low risk. The included studies were of moderate to very low-certainty evidence. Pooled data demonstrated that exercise training may have little or no difference on physical fitness (VO₂ max) compared to usual care (mean difference (MD) 0.05 L/min^-1, 95% confidence interval (CI) -0.03 to 0.13; I² = 0%; 2 studies, 381 participants; low-certainty evidence). Included studies also showed in terms of adverse effects (safety), that it may be of benefit to exercise (8 studies, 507 participants; low-certainty evidence). Furthermore, exercise training probably made little or no difference on HRQoL (EORTC global health status subscale) compared to usual care (MD 2.29, 95% CI -1.06 to 5.65; I² = 0%; 3 studies, 472 participants; moderate-certainty evidence). However, exercise training probably reduces fatigue (multidimensional fatigue inventory) compared to usual care (MD -1.05, 95% CI -1.83 to -0.28; I² = 0%; 3 studies, 449 participants moderate-certainty evidence). No studies reported postoperative outcomes.

AUTHORS' CONCLUSIONS

The findings should be interpreted with caution in view of the low number of studies, the overall low-certainty of the combined evidence, and the variation in included cancer types (mainly people with breast cancer), treatments, exercise interventions, and outcomes. Exercise training may, or may not, confer modest benefit on physical fitness and HRQoL. Limited evidence suggests that exercise training is probably not harmful and probably reduces fatigue. These findings highlight the need for more RCTs, particularly in the neoadjuvant setting.

Efficacy and safety of consolidation chemotherapy during the resting period in patients with local advanced rectal cancer

It remains controversial as to whether a long interval between neoadjuvant chemoradiotherapy (NCRT) and surgery may provide clinical benefits for patients with local advanced rectal cancer (LARC). The addition of consolidation chemotherapy during the resting period was recently considered as a treatment option. The present study aimed to verify the efficacy and safety of consolidation chemotherapy during the resting period in patients with LARC. A total of 156 patients with local advanced stage T3-4N0-2 rectal cancer were enrolled between January 2010 and July 2016. Patients were divided into two groups, those who received consolidation chemotherapy prior to surgery (n=76) and the control group who did not (n=80). Multivariate logistic regression and the Kaplan-Meier method were used to explore the predictors of pathological complete response (pCR) and survival. The demographic and tumor characteristics were comparable between the two groups. The consolidation group yielded significantly higher pCR and near pCR rates compared with the control group (P=0.015). Patients in the consolidation group who also underwent standard adjuvant chemotherapy displayed improved 3-year disease-free survival (DFS) compared with the control group (P=0.036). Notably, the addition of consolidation chemotherapy between NCRT and surgery did not significantly increase the incidence of surgical complications and grade 3 or 4 toxicities when compared with the control group. Consolidation chemotherapy was associated with increased pCR/near pCR rates and improved 3-year DFS, and displayed a manageable safety profile. The present study provided primary evidence for the efficacy and safety of consolidation chemotherapy in LARC. Further prospective studies are warranted in the future to verify these results.

Non-operative management of rectal cancer: understanding tumor biology

The management of locally-advanced rectal cancer involves a combination of chemotherapy, chemoradiation, and surgical resection to provide excellent local tumor control and overall survival. However, aspects of this multimodality approach are associated with significant morbidity and long-term sequelae. In addition, there is growing evidence that patients with a clinical complete response to chemotherapy and chemoradiation treatments may be safely offered initial non-operative management in a rigorous surveillance program. Weighed against the morbidity and significant sequelae of rectal resection, recognizing how to best optimize non-operative strategies without compromising oncologic outcomes is critical to our understanding and treatment of this disease.

Novelties in treatment of locally advanced rectal cancer

Treatment of locally advanced rectal cancer is evolving through surgical innovation and paradigm shifts in neoadjuvant treatment. Whereas local recurrence was a significant concern before the systematic implementation of neoadjuvant chemoradiation therapy and surgery according to total mesorectal excision principles, distant relapse remains a major drawback. Hence, efforts in recent years have focused on delivering preoperative chemotherapy regimens to overcome compliance issues with adjuvant administration. In parallel, new surgical techniques, including transanal video-assisted total mesorectal excision and robot-assisted surgery, emerged to face the challenge to navigate in the deep and narrow spaces of the pelvis. Furthermore, patients experiencing a complete response after neoadjuvant treatment might even escape surgery within a close surveillance strategy. This novel "watch and wait" concept has gained interest to improve quality of life in highly selected patients. This review summarizes recent evidence and controversies and provides an overview on timely and innovative aspects in the treatment of locally advanced rectal cancer.

Systematic review of treatment intensification using novel agents for chemoradiotherapy in rectal cancer

BACKGROUND

With the well established shift to neoadjuvant treatment for locally advanced rectal cancer, there is increasing focus on the use of radiosensitizers to improve the efficacy and tolerability of radiotherapy. There currently exist few randomized data exploring novel radiosensitizers to improve response and it is unclear what the clinical endpoints of such trials should be.

METHODS

A qualitative systematic review was performed according to the PRISMA guidelines using preset search criteria across the PubMed, Cochrane and Scopus databases from 1990 to 2017. Additional results were generated from the reference lists of included papers.

RESULTS

A total of 123 papers were identified, of which 37 were included; a further 60 articles were obtained from additional referencing to give a total of 97 articles. Neoadjuvant radiosensitization for locally advanced rectal cancer using fluoropyrimidine-based chemotherapy remains the standard of treatment. The oral derivative capecitabine has practical advantages over 5-fluorouracil, with equal efficacy, but the addition of a second chemotherapeutic agent has yet to show a consistent significant efficacy benefit in randomized clinical assessment. Preclinical and early-phase trials are progressing with promising novel agents, such as small molecular inhibitors and nanoparticles.

CONCLUSION

Despite extensive research and promising preclinical studies, a definite further agent in addition to fluoropyrimidines that consistently improves response rate has yet to be found.

Phase II trial of capecitabine plus oxaliplatin (CAPOX) as perioperative therapy for locally advanced rectal cancer

PURPOSE

The standard strategy for locally advanced lower rectal cancer is chemoradiotherapy followed by total mesorectal excision (TME) in Western countries and TME followed by adjuvant chemotherapy without preoperative treatment in Japan.

METHODS

This phase II trial evaluated the efficacy of a preoperative CAPOX chemotherapy regimen without radiation therapy for patients with locally advanced rectal cancer. The primary endpoint was 2-year disease-free survival.

RESULTS

The trial enrolled 45 patients from 9 institutions between 2012 and 2014. The mean age was 63.5 (29-74) years; 31 patients were male. Most patients (n = 41) received preoperative chemotherapy (CTx), and the preoperative CTx completion rate was 95.2%. R0 resection after CTx was performed in 41 patients. The pathological complete response rate was 7.3% (3/41). After surgery, 35 patients (85.3%) received adjuvant CTx, and 22 of 35 completed the protocol treatment. The follow-up period ranged from 0.71 to 4.68 years (median 2.86 years). There was recurrence in 13 of 40 patients who underwent R0 resection, and the 2-year disease-free survival rate and overall survival rate were 71.6 and 92.7%, respectively.

CONCLUSIONS

Here we report the completion rates for neoadjuvant CTx and adjuvant CTx, the pathological complete response rate, and the mid-term prognosis. The results indicate that CAPOX followed by TME may be a safe treatment strategy for locally advanced rectal cancer.

MRI-Based Apparent Diffusion Coefficient for Predicting Pathologic Response of Rectal Cancer After Neoadjuvant Therapy: Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this study was to assess the use of apparent diffusion coefficient (ADC) during DWI for predicting complete pathologic response of rectal cancer after neoadjuvant therapy.

MATERIALS AND METHODS

A systematic review of available literature was conducted to retrieve studies focused on the identification of complete pathologic response of locally advanced rectal cancer after neoadjuvant chemoradiation, through the assessment of ADC evaluated before, after, or both before and after treatment, as well as in terms of the difference between pretreatment and posttreatment ADC. Pooled mean pretreatment ADC, posttreatment ADC, and Δ-ADC (calculated as posttreatment ADC minus pretreatment ADC divided by pretreatment ADC and multiplied by 100) in complete responders versus incomplete responders were calculated. For each parameter, we also pooled sensitivity and specificity and calculated the area under the summary ROC curve.

RESULTS

We found 10 prospective and eight retrospective studies. Overall, pathologic complete response was observed in 22.2% of patients. Pooled mean pretreatment ADC in complete responders was 0.84 × 10^-3 mm²/s versus 0.89 × 10^-3 mm²/s in incomplete responders (p = 0.33). Posttreatment ADC values were 1.51 × 10^-3 mm²/s and 1.29 × 10^-3 mm²/s, in complete and incomplete responders, respectively (p = 0.00001). The Δ-ADC percentages were also significantly higher in complete responders than in incomplete responders (59.7% vs 29.7%, respectively, p = 0.016). Pooled sensitivity, specificity, and AUC were 0.743, 0.755, and 0.841 for pretreatment ADC; 0.800, 0.737, and 0.782 for posttreatment ADC; and 0.832, 0.806, and 0.895 for Δ-ADC.

CONCLUSION

Use of ADC during DWI is a promising technique for assessment of results of neoadjuvant treatment of rectal cancer.

Induction chemotherapy followed by neoadjuvant chemoradiotherapy and surgery in locally advanced rectal cancer: preliminary results of a phase II study

Background and purpose

To report preliminary results of induction chemotherapy (IC) followed by neoadjuvant chemoradiotherapy (CRT) and surgery in locally advanced rectal cancer (LARC) patients.

Materials and methods

This is the preliminary evaluation of a phase II study. Patients with histologically proven rectal adenocarcinoma, stage II-III disease, who met the inclusion criteria, received induction FOLFOXIRI (5-FU, leucovorin, oxaliplatin and irinotecan) regimen in combination with targeted agents followed by CRT and surgery. Analysis of the first 8 patients was required to confirm the treatment feasibility before the accrual of 20 additional patients.

Results

The first 8 patients were evaluated. The median follow-up time was 23 months. There were no treatment-related deaths. Trimodality strategy was well tolerated with high compliance and a good level of toxicity. There were no evidence of febrile neutropenia and any grade 4 adverse events were recorded. Three patients had pathologic complete response (pCR) and 1 patient had a nearly pCR (ypT1 ypN0).

Conclusion

Preliminary results are encouraging. FOLFOXIRI regimen plus targeted agents followed by CRT and surgery seems a safe approach. Longer follow-up and higher number of patients are mandatory to confirm such findings.

A prospective phase II study of pre-operative chemotherapy then short-course radiotherapy for high risk rectal cancer: COPERNICUS

BACKGROUND

Neoadjuvant chemotherapy (NAC) allows earlier treatment of rectal cancer micro-metastases but is not standard of care. There are currently no biomarkers predicting long-term progression-free survival (PFS) benefit from NAC.

PATIENTS AND METHODS

In this single arm phase II trial, patients with non-metastatic magnetic resonance imaging (MRI)-defined operable rectal adenocarcinoma at high risk of post-operative metastatic recurrence, received 8 weeks of oxaliplatin/fluorouracil NAC then short-course preoperative radiotherapy (SCPRT) before immediate surgery. Sixteen weeks of post-operative adjuvant chemotherapy (AC) was planned. A pelvic MRI was performed at week 9 immediately post-NAC, before SCPRT. The primary end point was feasibility assessed by completion of protocol treatment up to and including surgery. Secondary endpoints included compliance, toxicity, downstaging efficacy, and PFS.

RESULTS

In total 60 patients were recruited May 2012-June 2014. In total 57 patients completed protocol treatment, meeting the primary endpoint. Compliance with NAC was much better than AC: Comparing NAC vs. AC, the median percentage dose intensity for fluoropyrimidine was 100% vs. 63% and for oxaliplatin 100% vs. 45%. Treatment-related toxicity was acceptable with no treatment-related deaths. Post-NAC MRI showed 44 tumours (73%) were T-downstaged and 22 (37%) had excellent MRI tumour regression grade (mrTRG 1-2). Median follow-up was 27 months with 2-year PFS of 86.2% (10 events). On exploratory analysis, post-NAC mrTRG predicted PFS with no event among those with excellent regression.

CONCLUSION

The regimen was well tolerated with effective downstaging and encouraging PFS. mrTRG response to NAC may be a new prognostic factor for long-term PFS, but needs validation in larger studies.

Adoption of Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer

Importance

Treatment of locally advanced rectal (LARC) cancer involves chemoradiation, surgery, and chemotherapy. The concept of total neoadjuvant therapy (TNT), in which chemoradiation and chemotherapy are administered prior to surgery, has been developed to optimize delivery of effective systemic therapy aimed at micrometastases.

Objective

To compare the traditional approach of preoperative chemoradiation (chemoRT) followed by postoperative adjuvant chemotherapy with the more recent TNT approach for LARC.

Design, Setting, and Participants

A retrospective cohort analysis using Memorial Sloan Kettering Cancer Center (MSK) records from 2009 to 2015 was carried out. A total of 811 patients who presented with LARC (T3/4 or node-positive) were identified.

Exposures

Of the 811 patients, 320 received chemoRT with planned adjuvant chemotherapy and 308 received TNT (induction fluorouracil- and oxaliplatin-based chemotherapy followed by chemoRT).

Main Outcomes and Measures

Treatment and outcome data for the 2 cohorts were compared. Dosing and completion of prescribed chemotherapy were assessed on the subset of patients who received all therapy at MSK.

Results

Of the 628 patients overall, 373 (59%) were men and 255 (41%) were women, with a mean (SD) age of 56.7 (12.9) years. Of the 308 patients in the TNT cohort, 181 (49%) were men and 127 (49%) were women. Of the 320 patients in the chemoRT with planned adjuvant chemotherapy cohort, 192 (60%) were men and 128 (40%) were women. Patients in the TNT cohort received greater percentages of the planned oxaliplatin and fluorouracil prescribed dose than those in the chemoRT with planned adjuvant chemotherapy cohort. The complete response (CR) rate, including both pathologic CR (pCR) in those who underwent surgery and sustained clinical CR (cCR) for at least 12 months posttreatment in those who did not undergo surgery, was 36% in the TNT cohort compared with 21% in the chemoRT with planned adjuvant chemotherapy cohort.

Conclusions and Relevance

Our findings provide additional support for the National Comprehensive Cancer Network (NCCN) guidelines that categorize TNT as a viable treatment strategy for rectal cancer. Our data suggest that TNT facilitates delivery of planned systemic therapy. Long-term follow-up will determine if this finding translates into improved survival. In addition, given its high CR rate, TNT may facilitate nonoperative treatment strategies aimed at organ preservation.

Selective use of radiation for locally advanced rectal cancer: one size does not fit all

The last three decades have seen several major advances in the multidisciplinary management of locally advanced rectal cancer (LARC). Although rectal cancer management varies globally, the standard of care for clinical stage II/III rectal cancer in North America remains chemoradiation followed by total mesorectal excision and adjuvant therapy. In this review we evaluate the evidence for neoadjuvant therapy in LARC and the variety of treatment options available. We identify heterogeneity of outcomes in stage II/III rectal cancer, leading to the potential for overtreatment. The PROSPECT Trial is a multicenter, international effort to determine whether a selective approach to provision of radiotherapy in stage II/III LARC is a viable treatment option. Unlike many other studies, the aim of PROSPECT is to reduce treatment rather than increase the intensity of preoperative therapy. LARC is a heterogeneous disease with varying risk of relapse. Studies are underway to attempt to individualize care to avoid overtreatment while maintaining excellent oncologic outcomes.

Systemic immune response induced by oxaliplatin-based neoadjuvant therapy favours survival without metastatic progression in high-risk rectal cancer

Background

Systemic failure remains a challenge in rectal cancer. We investigated the possible systemic anti-tumour immune activity invoked within oxaliplatin-based neoadjuvant therapy.

Methods

In two high-risk patient cohorts, we assessed the circulating levels of the fms-like tyrosine kinase 3 ligand (Flt3L), a factor reflecting both therapy-induced myelosuppression and activation of tumour antigen-presenting dendritic cells, at baseline and following induction chemotherapy and sequential chemoradiotherapy, both modalities containing oxaliplatin. The primary end point was progression-free survival (PFS).

Results

In both cohorts, the median Flt3L level was significantly higher at completion of each sequential modality than at baseline. The 5-year PFS (most events being metastatic progression) was 68% and 71% in the two cohorts consisting of 33% and 52% T4 cases. In the principal cohort, a high Flt3L level following the induction chemotherapy was associated with low risk for a PFS event (HR: 0.15; P < 0.01). These patients also had available dose scheduling and toxicity data, revealing that oxaliplatin dose reduction during chemoradiotherapy, undertaken to maintain compliance to the radiotherapy protocol, was associated with advantageous PFS (HR: 0.47; P = 0.046).

Conclusion

In high-risk rectal cancer, oxaliplatin-containing neoadjuvant therapy may promote an immune response that favours survival without metastatic progression.

Area of residual tumor is a robust prognostic marker for patients with rectal cancer undergoing preoperative therapy

The aim of this study was to elucidate differences in the histological features of rectal cancer between patients treated with preoperative chemoradiotherapy and those treated with preoperative chemotherapy. Area of residual tumor (ART) was also evaluated for its utility as a potential prognostic marker between them. Sixty‐eight patients with rectal cancer who underwent sphincter‐saving surgery were enrolled in this study. Of these, 39 patients received preoperative chemoradiotherapy (CRT group) and 29 patients received preoperative (neoadjuvant) chemotherapy (NAC group). Area of residual tumor was determined by using morphometric software. Tumors in the two groups were compared for differences in their histological features and clinical outcomes. Tumors in the CRT and NAC groups varied greatly with regard to their histological features after preoperative therapy. Tumors in the CRT group showed more marked fibrosis than those in the NAC group. The total ART were significantly smaller in tumors in the CRT group than those in the NAC group. However, in circumferential resection margin‐negative pathologic stage 0‐III cases, clinical outcomes were not statistically different between the CRT and NAC groups. Both ART and pathologic TNM classification were associated with clinical outcome in preoperative CRT and NAC groups, but Dworak regression grade and fibrotic change were not. Tumors in those undergoing preoperative CRT and NAC were shown to differ significantly in their histological features. Area of residual tumor‐based assessment may provide useful prognostic information, regardless of preoperative therapy.

Pilot Study of Intense Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: Retrospective Review of a Phase II Study

Aims and Background

Locally advanced rectal adenocarcinoma is typically treated with neoadjuvant chemoradiotherapy and surgery. We assessed the effect of an additional cycle of capecitabine/oxaliplatin chemotherapy before surgery in 57 patients with T3/4, N+/- or T1/2, N+ rectal cancer.

Materials and Study Design

Radiotherapy (total dose, 50.4 Gy) was combined with three cycles of chemotherapy (two cycles concomitant with radiotherapy), and each cycle consisted of oxaliplatin (130 mg/m2 on day 1) and capecitabine (825 mg/m2, twice per day from day 1 to day 14) for 21 days. In addition to assessing the safety of this treatment, the primary endpoint was pathological complete response (pCR). The secondary endpoint was the change in primary tumor and node stage from pre-treatment to post-surgery.

Results

Eleven patients (19%) experienced complete tumor regression and 23 patients (40%) experienced tumor regression grade 3. Tumor down-staging occurred in 31 patients (54.4%) and down-staging of nodes occurred in 25 patients (43.9%). There was a significant difference in tumor stage between pre-treatment and post-surgery (P <0.001). Patients with less advanced N stages had significantly better recurrence-free survival but similar metastasis-free survival and overall survival. Tumor regression grade was not associated with overall survival, recurrence-free survival or metastasis-free survival. The most common adverse events were pulmonary infection (n = 6, 10.5%) and intestinal obstruction (n = 6, 10.5%).

Conclusions

An additional cycle of chemotherapy given after chemoradiotherapy and before surgery provided good efficacy and had a satisfactory safety profile in patients with locally advanced rectal cancer.

Comparison between Intensified Neoadjuvant Treatment and Standard Preoperative Chemoradiation for Rectal Cancer

Objectives

The aim of the current study was to compare a neoadjuvant regimen containing oxaliplatin with standard preoperative treatment for rectal cancer.

Methods

From December 2006 to December 2007, 20 patients with rectal cancer were treated at our Institution with the weekly addition of oxaliplatin (50 mg/m2) to radiotherapy (50.4–54.0 Gy in 28–30 daily fractions) and continuous infusion of 5-fluorouracil (200 mg/m2). The results of the regimen were compared with a historical control group including 21 consecutive patients previously treated with standard 5-fluorouracil treatment from December 2004 to October 2006.

Results

Both the rate of sphincter preservation in low rectal cancer (91.7% vs 36.4%, P = 0.009) and the rate of downstaging (84.2% vs 47.6%, P = 0.023) were higher in the oxaliplatin group than in the control group. Pathological complete response was achieved in 8 patients (42.1%) in the oxaliplatin group and in 4 patients (19.0%) in the control group (P = 0.172). When ypT0-pT1 stages were analyzed together, the P value was 0.051. Acute toxicity was increased in the oxaliplatin group, with a higher incidence of G3 diarrhea and pelvic pain than in the control group (30.0% vs 14.3%, P = NS).

Conclusions

Our data seem to correlate the addition of oxaliplatin to the standard treatment for rectal cancer with higher rates of sphincter preservation, down-staging and complete response. Toxicity is increased and requires careful monitoring. However, our results refer to a retrospective comparison of a small series of patients and need to be validated by the large, phase III randomized trial currently ongoing.

The role of chemotherapy in localized and locally advanced rectal cancer: A systematic revision

Curative treatment of rectal cancer depends on an optimal surgical resection, with the addition of neoadjuvant radiotherapy (RT) with or without concomitant chemotherapy (ChT) in more advanced tumors. The role of adjuvant ChT is controversial and a more intensified neoadjuvant approach with the addition of ChT before or after RT, or even as single modality, is currently being explored in trials. A systematic review selecting randomised phase II and III trials on the role of ChT in localized rectal cancer was performed. Data show that neoadjuvant ChRT improves locoregional control in resected rectal cancer. Short-course RT (SCRT) could give similar outcomes to ChRT. The addition of oxaliplatin to neoadjuvant ChRT marginally increases the pathological complete remission rate without improving survival and increasing toxicity. A more intensified approach remains investigational as trials to date have not shown significant advantages. Adjuvant ChT trials after preoperative ChRT are contentious, although the addition of oxaliplatin in high risk patients may benefit outcomes. Despite a wide heterogeneity in the target population, different staging procedures and diverse treatment approaches among different trials, this systematic review confirms the role of ChT in combination with neoadjuvant long-course RT. Adjuvant ChT could be of value in selected patients with high-risk features, mainly if they do not respond to neoadjuvant RT. Further investigation is warranted on more intensified neoadjuvant regimens including ChT for MRI-defined high-risk patients.