Total neoadjuvant therapy for rectal cancer: An emerging option

Caring for Patients with Rectal Cancer During the COVID-19 Pandemic

The extraordinary spread of the novel coronavirus (COVID-19) has dramatically and rapidly changed the way in which we provide medical care for patients with all diagnoses. Conservation of resources, social distancing, and the risk of poor outcomes in COVID-19-positive cancer patients have forced practitioners and surgeons to completely rethink routine care. The treatment of patients with rectal cancer requires both a multidisciplinary approach and a significant amount of resources. It is therefore imperative to rethink how rectal cancer treatment can be aligned with the current COVID-19 pandemic paradigms. In this review, we discuss evidence-based recommendations to optimize oncological outcomes during the COVID-19 pandemic.

Genome-Wide Identification of a Novel Autophagy-Related Signature for Colorectal Cancer

Background:

Plenty of evidence has suggested that autophagy plays a crucial role in the biological processes of cancers. This study aimed to screen autophagy-related genes (ARGs) and establish a novel a scoring system for colorectal cancer (CRC).

Methods:

Autophagy-related genes sequencing data and the corresponding clinical data of CRC in The Cancer Genome Atlas were used as training data set. The GSE39582 data set from the Gene Expression Omnibus was used as validation set. An autophagy-related signature was developed in training set using univariate Cox analysis followed by stepwise multivariate Cox analysis and assessed in the validation set. Then we analyzed the function and pathways of ARGs using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Finally, a prognostic nomogram combining the autophagy-related risk score and clinicopathological characteristics was developed according to multivariate Cox analysis.

Results:

After univariate and multivariate analysis, 3 ARGs were used to construct autophagy-related signature. The KEGG pathway analyses showed several significantly enriched oncological signatures, such as p53 signaling pathway, apoptosis, human cytomegalovirus infection, platinum drug resistance, necroptosis, and ErbB signaling pathway. Patients were divided into high- and low-risk groups, and patients with high risk had significantly shorter overall survival (OS) than low-risk patients in both training set and validation set. Furthermore, the nomogram for predicting 3- and 5-year OS was established based on autophagy-based risk score and clinicopathologic factors. The area under the curve and calibration curves indicated that the nomogram showed well accuracy of prediction.

Conclusions:

Our proposed autophagy-based signature has important prognostic value and may provide a promising tool for the development of personalized therapy.

Report from the 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Saskatoon, Saskatchewan; 28-29 September 2018

The 20th annual Western Canadian Gastrointestinal Cancer Consensus Conference was held in Saskatoon, Saskatchewan, 28-29 September 2018. This interactive multidisciplinary conference is attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancers. In addition, invited speakers from other provinces participate. Surgical, medical, and radiation oncologists, and allied health care professionals participated in presentations and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancers.

Neoadjuvant chemo-radiotherapy for cT3N0 rectal cancer: any benefit over upfront surgery? A propensity score-matched study

PURPOSE

Benefits of neoadjuvant chemo-radiotherapy (CRT) are well known for locally advanced and/or node-positive rectal cancer, but the best timing for CRT has been less explored for cT3N0 patients. The aim of the present study was to compare the 5-year disease-free survival (DFS) probability between neoadjuvant CRT and upfront surgery in patients affected by cT3N0 rectal cancer.

METHODS

A retrospective review of 105 patients affected by cT3N0 rectal cancer, staged by pelvic magnetic resonance imaging and treated at the National Cancer Institute of Milan between 2011 and 2017, was performed: 42 (40.0%) were treated by neoadjuvant CRT and 63 (60.0%) by upfront surgery. Propensity score matching was performed to avoid selection bias, and Cox multivariate regression was used to analyze outcomes.

RESULTS

The 5-year DFS probability was 87.5% in neoadjuvant CRT patients vs. 90.0% in upfront surgery cases (Log-rank p = 0.76). The 5-year loco-regional recurrence-free survival probability was respectively 96.8% vs. 96.3% (Log-rank p = 0.954). On multivariate analysis, neoadjuvant CRT had no impact on DFS when compared to upfront surgery (adjusted HR 0.71, 95%CI 0.18-2.70, p = 0.613), but 61.9% of upfront surgery cases were treated by adjuvant chemo-radiation (adjusted HR 0.41, 95%CI 0.11-1.57, p = 0.196). The only independent predictor of improved DFS was age at diagnosis (adjusted HR 0.95, p = 0.017).

CONCLUSION

CRT should be considered for cT3N0 patients, but its timing (neoadjuvant vs. adjuvant) seems not to affect the disease-free survival in the present cohort of patients.

High expression of microRNA-199a-5p is associated with superior clinical outcomes in patients with locally advanced rectal cancer

PURPOSE

We aimed to identify biomarkers of response to preoperative CRT in patients with LARC using comprehensive miRNA analysis.

METHODS

This study included 65 rectal cancer specimens and 89 serum samples from patients diagnosed with LARC and treated with preoperative. All specimens were collected before CRT for evaluation of biologic differences between the good and poor CRT response groups (ypStage 0/I versus II/III/IV). For specific miRNA discovery, 800 miRNAs in 20 rectal cancer specimens were analyzed with a NanoString assay. For validation, a total of 65 tissue and 89 serum samples were tested with reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

In the discovery set, 16 target miRNAs were detected. In the validation set, higher expression of three miRNAs (miR-199a/b-3p, miR-199a-5p, and miR-199b-5p) was significantly associated with better response to CRT. In the univariate survival analysis, upregulation of these three miRNAs was associated with superior relapse-free survival (RFS) and overall survival (OS). Meanwhile, only a higher level of tissue miR-199a-5p was associated with superior RFS [hazard ratio (HR), 0.0.91; 95% confidence interval (CI) 0.035-0.580; p = 0.002] and OS (HR, 0.272; 95% CI 0.023-0.658; p < 0.001) in the multivariate survival analysis. Also, a higher level of exosomal miR-199b-5p correlated with better response to CRT (p = 0.0397).

CONCLUSION

High expression of tissue miR-199a/b-3p, miR-199a-5p, and miR-199b-5p was significantly associated with response to CRT, and a high level of tissue miR-199a-5p was associated with superior survival outcomes. Also, upregulated exosomal miR-199b-5p correlated with CRT response, reflecting its promise as a circulating biomarker of CRT response in patients with LARC.

Delay to Adjuvant Chemotherapy: Survival and Recurrence in Patients of Rectal Cancer Treated with Neo-adjuvant Chemoradiotherapy and Surgery

PURPOSE

This aim of the study is to evaluate the survival function and hazard risks of delayed adjuvant chemotherapy (ChT) to distant recurrence risk in patients with non-metastatic rectal cancer treated with neoadjuvant chemoradiotherapy (CRT) and surgery.

METHODS

A single tertiary hospital retrospective cohort study of a duration of 5 years between January 2012 and December 2016 was performed. As no previous study shown a temporal relationship of delay to adjuvant/systemic ChT leading to increased risk of metastatic disease, we compared between our proposed cut-off with the median and mean value determined by our dataset. Time to event analysis and log rank tests were conducted.

RESULTS

A total of 269 patients with rectal cancer were identified. Two hundred eighteen patients were ineligible, leaving 51 patients for final analysis. Patients in the non-delayed group at 23 (proposed) and 25 (median) weeks' cut-off reported better 5 years' disease free survival (DFS) compared with the delayed group by 4.1% and 0.8%. Inversely, at the cut-off 28 (mean) weeks, the delayed group had a better DFS by 4.4%. Females and patients less than 60 years old had better 5-year DFS by 22.8% and 24%. Delayed group has a higher hazard risk ratio (HR) of 1.28 of distant recurrence compared with non-delayed at 23 weeks' cut-off.

CONCLUSION

This study has demonstrated delaying a patient to adjuvant ChT will lower their DFS and increase their HR compared with those whose treatment is not delayed. We have long been too focused on local control; hence, priority needs to be shifted to efforts in managing potential distant disease in a timely manner.

The Role of Adjuvant Chemotherapy in ypT0N0 Rectal Adenocarcinoma

BACKGROUND

In patients who develop a complete pathologic response (ypT0N0) following neoadjuvant chemoradiation, the benefits of postoperative chemotherapy remain uncertain. This study aims to determine whether treatment with adjuvant chemotherapy in ypT0N0 patients affects short- and long-term outcomes.

METHODS

From January 2000 to December 2015, 992 patients at our institution underwent surgery for rectal adenocarcinoma following treatment with neoadjuvant chemoradiation. A complete pathologic response was noted in 96 (9.7%) patients. Adjuvant chemotherapy was administered to 60 (62.5%) patients. We reviewed clinical and pathological records and compared outcomes in ypT0N0 patients who received adjuvant chemotherapy to those who did not.

RESULTS

The mean age of patients who received adjuvant chemotherapy was 55.6 ± 11.5 years, compared to 62.1 ± 11.7 years for those who did not (p = 0.008). Among the two groups, mean follow-up time after surgery was 5.3 ± 4.1 years for the adjuvant group and 8.3 ± 5.5 years for the non-adjuvant cohort (p = 0.003). The 1, 3, and 5-year survival rates were 100.0%, 97.7%, and 92.1% for patients who received adjuvant chemotherapy and 97.2%, 94.1%, and 90.7% for those who did not (p = 0.382). In a subanalysis of patients with available follow-up information, we observed 3/53 (5.7%) disease recurrences in patients who received adjuvant chemotherapy, compared to 2/18 (11.1%) in those who were not treated postoperatively (p = 0.456).

CONCLUSION

In patients with ypT0N0 rectal adenocarcinoma, we found equivalent survival and recurrence outcomes. Further study will be necessary to determine the importance of adjuvant chemotherapy following ypT0N0 resection.

Comparing outcomes following total neoadjuvant therapy and following neoadjuvant chemoradiation therapy in patients with locally advanced rectal cancer

BACKGROUND

There is recent interest in treating locally advanced rectal cancer (LARC) patients with total neoadjuvant therapy (TNT). However, whether TNT is associated with improved overall survival (OS) remains unknown. This study compares outcomes following TNT and following neoadjuvant chemoradiation therapy (nCRT) in patients with LARC, clinically defined cT3/4 or node positive disease, using the National Cancer Database.

METHODS

LARC patients diagnosed between 2004-2015 were included. TNT was defined as multi-agent chemotherapy given at least 2 months before RT followed by pre-operative chemoradiation therapy and definitive surgery without adjuvant chemotherapy. nCRT was defined as pre-operative RT and chemotherapy started within 2 weeks from each other followed by definitive surgery with or without adjuvant chemotherapy. Kaplan-Meier curve with logrank test and multivariable Cox proportional hazards regression modelling were used to analyse the primary endpoint of overall survival (OS). Multivariable logistic regression modelling was used for secondary outcomes to determine if TNT is associated with pathological complete response (pCR), defined as ypT0N0, and negative circumferential resection margin (CRM).

FINDINGS

Data from 372 TNT patients and 707 nCRT patients were analysed after a 2:1 propensity matching with replacement. Kaplan-Meier curve showed that OS with TNT was comparable to that with nCRT (p = 0•16). The 5-year OS rates for TNT and nCRT were 73•6% vs. 78•5% (p = 0•20). Multivariable Cox proportional hazards regression modelling confirmed no difference in OS between TNT and nCRT (HR = 1•21, p = 0•25). With TNT, 16•9% patients achieved pCR, whereas 13•1% patients achieved pCR with nCRT (p = 0•12). TNT was not found to be significantly associated with pCR (OR = 1•36, p = 0•13) or negative CRM (OR = 1•77, p = 0•19) in multivariable logistic regression modelling.

INTERPRETATION

With results from current clinical trials pending, our data suggested that TNT and nCRT resulted in similar survival, while TNT led to higher pCR and CRM negative rate, albeit not statistically significant.

Compliance to Adjuvant Chemotherapy of Patients Who Underwent Surgery for Rectal Cancer: Report from a Multi-institutional Research Network

INTRODUCTION

Adjuvant chemotherapy for locally advanced rectal cancer is associated with improved overall survival. However, recent evidence from randomized trials showed a compliance rate of 43 to 73%, which may affect efficacy. The aim of this multicenter retrospective analysis was to investigate the compliance rate to adjuvant treatment for patients who underwent rectal surgery for cancer.

METHODS

Patients who underwent surgery with curative intent for rectal cancer in six Italian colorectal centers between January 2013 and December 2017 were retrospectively reviewed. Exclusion criteria were age less than 18 years, palliative or emergency surgery, and stage IV disease. Parameters of interest were patients' characteristics, preoperative tumor stage, neo-adjuvant chemoradiation therapy, intra-operative and postoperative outcomes. Although the participating centers referred to the same treatment guidelines for treatment, the chemotherapy regiment was not standardized across the institutions. Reasons for not starting adjuvant chemotherapy when indicated, interruption, and modification of drug regimen were collected to investigate compliance.

RESULTS

A total of 572 patients were included in the analysis. Two hundred and fifty-two (44.1%) patients received neo-adjuvant chemoradiation therapy. All patients underwent high anterior rectal resection, low anterior rectal resection, or Miles' procedure. Of 399 patients with an indication to adjuvant chemotherapy, 176 (44.1%) completed the treatment as planned. Compliance for patients who started chemotherapy was 56% (95% CI 50.4-61.6%). Sixty-six patients interrupted the treatment, 76 patients significantly reduced the drug dose, and 41 patients had to switch to other therapeutic regimens.

CONCLUSIONS

The present multicenter investigation reports a low compliance rate to adjuvant chemotherapy after rectal resection for cancer. Multidisciplinary teams should focus on future effort to improve compliance for these patients.

Emerging strategies in the initial management of locally advanced rectal cancer

The initial management of locally advanced rectal cancer continues to evolve and formulating the ideal treatment plan remains challenging, with a multitude of emerging treatment strategies and either limited or inconsistent data to support these. The main objective of neoadjuvant treatment is to maximize disease control and minimize toxicity and impact on quality of life. Ultimately, the optimal approach needs to be personalized to the individual. In this Review, we discuss the various strategies currently used and being further investigated in the initial treatment of patients presenting with locally advanced rectal cancer. We describe the evidence behind the current standard of care recommendations and emerging new options, as well as potential biomarkers that may assist with further refining treatment selection.

Sequential short-course radiation therapy and chemotherapy in the neoadjuvant treatment of rectal adenocarcinoma

Background

There is continued debate regarding the optimal combinations of radiation therapy and chemotherapy in the preoperative treatment of locally advanced rectal adenocarcinomas. We report our single-institution experience of feasibility and early oncologic outcomes of short-course preoperative radiation therapy (5 Gy X 5 fractions) followed by consolidation neoadjuvant chemotherapy.

Methods

We reviewed the records of 26 patients with locally advanced rectal adenocarcinoma. All patients underwent short course radiotherapy (5 Gy X 5 fractions) followed by chemotherapy [either modified infusional and bolus 5-fluorouracail and oxalipatin (mFOLFOX6) or capecitabine and oxaliplatin] prior to consideration for surgery. A full course of chemotherapy was defined as at least 8 weeks of chemotherapy.

Results

There were five clinical (c) T2, 16 cT3, and five cT4 rectal tumors, with 88% cN+. Twenty-five patients received a median of 4 cycles (range 3 to 8) of mFOLFOX6 (with one cycle defined as a two-week period); one patient received 3 cycles of capecitabine and oxaliplatin. All patients completed SCRT; 81% completed the full course of neoadjuvant chemotherapy with 19% requiring dose reductions in chemotherapy, most commonly due to neuropathy. Nineteen patients underwent post-treatment endoscopic evaluation, and nine patients were noted to achieve a complete clinical response (CCR). Six of the nine patients who achieved CCR opted for a non-operative approach of watch-and-wait. Twenty patients underwent surgical resection; pathologic complete response was observed in seven (35%) of these twenty. The main radiation-associated toxicity was proctitis with CTCAE Grade 2 proctitis observed in seven patients (27%). Post-operative Clavien-Dindo Grade 3 complications within 30 days of surgery were identified in six patients (30%), with no Grade 4 or 5 adverse events. Median length of hospital stay was 4.5 days (range 2–16 days); three patients were readmitted within a 30 day period.

Conclusions

Short course preoperative radiotherapy followed by neoadjuvant chemotherapy was well-tolerated and achieved oncologic outcomes that compare favorably with short-course radiation therapy alone or long-course chemoradiotherapy. This regimen is associated with high rates of clinical and pathologic complete response.

The 2017 Assisi Think Tank Meeting on rectal cancer: A positioning paper

BACKGROUND AND PURPOSES

To describe current practice in the management of rectal cancer, to identify uncertainties that usually arise in the multidisciplinary team (MDT)'s discussions ('grey zones') and propose next generation studies which may provide answers to them.

MATERIALS AND METHODS

A questionnaire on the areas of controversy in managing T2, T3 and T4 rectal cancer was drawn up and distributed to the Rectal-Assisi Think Tank Meeting (ATTM) Expert European Board. Less than 70% agreement on a treatment option was indicated as uncertainty and selected as a 'grey zone'. Topics with large disagreement were selected by the task force group for discussion at the Rectal-ATTM.

RESULTS

The controversial clinical issues that had been identified within cT2-cT3-cT4 needed further investigation. The discussions focused on the role of (1) neoadjuvant therapy and organ preservation on cT2-3a low-middle rectal cancer; (2) neoadjuvant therapy in cT3 low rectal cancer without high risk features; (3) total neoadjuvant therapy, radiotherapy boost and the best chemo-radiotherapy schedule in T4 tumors. A description of each area of investigation and trial proposals are reported.

CONCLUSION

The meeting successfully identified 'grey zones' and, in the light of new evidence, proposed clinical trials for treatment of early, intermediate and advanced stage rectal cancer.

Interplay Between Autophagy and Apoptosis in Lycorine Hydrochloride-Induced Cytotoxicity of HCT116 Cells

The aim of this study was to investigate the antitumor effect of lycorine hydrochloride (LH) and discuss the correlation between LH-induced apoptosis and autophagy in the human colorectal cancer cell line HCT116. Here the results by the Cell Counting Kit-8 and colony formation assays showed that LH concentration-dependently decreased cell viability and colony formation in HCT116 cells, suggesting inhibition of cell proliferation by LH. By flow cytometry, LH was found to increase apoptotic rate in HCT116 cells. Mechanistically, Western blot results revealed that LH increased the expression of the protein of Bax and Caspase-3, and decreased Bcl-2 proteins expression. Moreover, the reverse transcriptase quantitative polymerase chain reaction and Western blot analysis also showed that LH increased the expression of Beclin-1 and LC3B-II/LC3B-I ratio, indicating that autophagy was induced by LH. LH induced autophagy via downregulating phospho-mammalian target of rapamycin and upregulating phospho-AMPK (5′ adenosine monophosphate-activated protein kinase). Furthermore, to understand the role of LH-induced autophagy and its association with apoptosis, cells were analyzed after Beclin-1 small interfering RNA transfection. The results indicated that the proapoptotic ability of LH was increased by inhibition of autophagy. In conclusion, the present investigation suggested that LH induced apoptosis and autophagy in HCT116 cells via the mitochondrial and AMPK/mTOR pathways. The suppression of autophagy promoted LH-induced apoptosis by modulating Beclin-1 and Bcl-2.

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

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

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

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

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

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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.

Evolving Treatment Options and Future Directions for Locally Advanced Rectal Cancer

Locally advanced rectal cancer can be biologically heterogeneous, but imaging advances have improved clinical assessment of primary tumor and involved lymph nodes in relation to pelvic structures and intended surgical planes. Contemporary treatment for rectal cancer is tailored to the individual patient through multidisciplinary collaboration among diagnosticians, surgeons, medical oncologists, and radiation oncologists to minimize local recurrence and distant metastases. Furthermore, patient preferences and quality of life preservation are becoming more relevant in the decision-making, and upcoming treatment strategies specifically are designed to minimize toxicities and long-term morbidity. Accumulating data have continued to support the use of total neoadjuvant therapy, namely the completion of: (1) multiagent cytotoxic chemotherapy; and (2) pelvic radiation with or without a radiosensitizing agent, before surgery. The total neoadjuvant therapy strategy not only eliminates potentially occult metastases early but also opens up the possibility of nonsurgical management for those who decline or are unfit for surgery. Finally, noncytotoxic agents in combination with established chemotherapy agents along with potentially predictive biomarkers are also being actively investigated to further improve the clinical outcomes of rectal cancer.

Randomized Phase II Trial of Chemoradiotherapy Plus Induction or Consolidation Chemotherapy as Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: CAO/ARO/AIO-12

PURPOSE

Total neoadjuvant therapy is a new paradigm for rectal cancer treatment. Optimal scheduling of preoperative chemoradiotherapy (CRT) and chemotherapy remains to be established.

PATIENTS AND METHODS

We conducted a multicenter, randomized, phase II trial using a pick-the-winner design on the basis of the hypothesis of an increased pathologic complete response (pCR) of 25% after total neoadjuvant therapy compared with standard 15% after preoperative CRT. Patients with stage II or III rectal cancer were assigned to group A for induction chemotherapy using three cycles of fluorouracil, leucovorin, and oxaliplatin before fluorouracil/oxaliplatin CRT (50.4 Gy) or to group B for consolidation chemotherapy after CRT. Secondary end points included toxicity, compliance, and surgical morbidity.

RESULTS

Of the 311 patients enrolled, 306 patients were evaluable (156 in group A and 150 in group B). CRT-related grade 3 or 4 toxicity was lower (37% v 27%) and compliance with CRT higher in group B (91%, 78%, and 76% v 97%, 87%, and 93% received full-dose radiotherapy, concomitant fluorouracil, and concomitant oxaliplatin in groups A and B, respectively); 92% versus 85% completed all induction/consolidation chemotherapy cycles, respectively. The longer interval between completion of CRT and surgery in group B (median 90 v 45 days in group A) did not increase surgical morbidity. A pCR in the intention-to-treat population was achieved in 17% in group A and in 25% in group B. Thus, only group B (P < .001), but not group A (P = .210), fulfilled the predefined statistical hypothesis.

CONCLUSION

Up-front CRT followed by chemotherapy resulted in better compliance with CRT but worse compliance with chemotherapy compared with group A. Long-term follow-up will assess whether improved pCR in group B translates to better oncologic outcome.

Systematic review of outcomes after total neoadjuvant therapy for locally advanced rectal cancer

BACKGROUND

Advances in surgical technique and the development of combined-modality therapy have led to significantly improved local control in rectal cancer. Distant failure rates however, remain high, ranging between 20 and 30 per cent. Additional systemic chemotherapy in the preoperative period has been proposed as a means of eradicating subclinical micrometastases and improving long-term survival. The purpose of this systematic review was to evaluate the current evidence regarding induction chemotherapy in combination with standard neoadjuvant chemoradiotherapy, in terms of oncological outcomes, in patients with rectal cancer.

METHODS

A systematic review of the literature was performed to evaluate oncological outcomes and survival in patients with rectal cancer who underwent induction chemotherapy and neoadjuvant chemoradiotherapy, followed by surgical resection. Four major databases (PubMed, Embase, Scopus and Cochrane) were searched. The review included all original articles published in English reporting long-term outcomes, specifically survival data, and was limited to prospective studies only.

RESULTS

A total of 686 studies were identified. After applying inclusion and exclusion criteria, ten studies involving 648 patients were included. Median follow-up was 53·7 (range 26-80) months. Five-year overall and disease-free survival rates were 74·4 and 65·4 per cent respectively. Weighted mean local recurrence and distant failure rates were 3·5 (range 0-7) and 20·6 (range 5-31) per cent respectively.

CONCLUSION

Total neoadjuvant therapy should be considered in patients with high-risk locally advanced rectal cancer owing to improved chemotherapy compliance and disease control. Further prospective studies are required to determine whether this approach translates into improved disease-related survival or increases the proportion of patients suitable for non-operative management.

Circulating Biomarkers for Response Prediction of Rectal Cancer to Neoadjuvant Chemoradiotherapy

Rectal cancer response to neoadjuvant Chemoradiotherapy (pCRT) is highly variable. In fact, it has been estimated that only about 21 % of patients show pathologic Complete Response (pCR) after therapy, while in most of the patients a partial or incomplete tumour regression is observed. Consequently, patients with a priori chemoradioresistant tumour should not receive the treatment, which is associated with substantial adverse effects and does not guarantee any clinical benefit. For Locally Advanced Rectal Cancer Patients (LARC), a standardized neoadjuvant treatment protocol is applied, the identification and the usefulness of prognostic or predictive biomarkers can improve the antitumoural treatment strategy, modifying the sequence, dose, and combination of radiotherapy, chemotherapy and surgical resection. For these reasons, a growing number of studies are actually focussed on the discovery and investigation of new predictive biomarkers of response to pCRT. In this review, we have selected the most recent literature (2012-2017) regarding the employment of blood-based biomarkers potentially predicting pCR in LARC patients and we have critically discussed them to highlight their real clinical benefit and the current limitations of the proposed methodological approaches.

Diagnostic performance of MRI- versus MDCT-categorized T3cd/T4 for identifying high-risk stage II or stage III colon cancers: a pilot study

PURPOSE

The aim of this study was to determine the diagnostic performance of magnetic resonance imaging (MRI)-categorized T3cd/T4 tumors for identifying high-risk stage II or stage III cancer in patients with curatively resectable colon cancer in comparison to that of multidetector computed tomography (MDCT).

MATERIALS AND METHODS

Thirty-eight patients with histopathologically indicated adenocarcinomas prospectively underwent MRI of the colon. Two radiologists independently and retrospectively assessed for T-category, including T3 substage (≤ T3ab vs. ≥ T3cd). The diagnostic accuracies and interreader agreements between assessments using each modality were compared using a pairwise comparison of receiver-operating characteristic curves and a weighted κ statistic, respectively.

RESULTS

Twenty-nine patients (76.3%) were histopathologically diagnosed with high-risk stage II or stage III colon cancer. The false-positive rate with MRI was lower than that with MDCT (0% vs. 7.9% for reader 1, 2.6% vs. 10.6% for reader 2). The diagnostic performance of MRI was better than that of MDCT across both readers (AUC: 0.707 vs. 0.506 [P = 0.032] for reader 1, 0.651 vs. 0.485 [P = 0.055] for reader 2). Moreover, MRI interreader agreement for the assessment of T3cd/T4 was significantly better than that of MDCT (κ = 0.821 vs. 0.391 [P = 0.017]).

CONCLUSION

The diagnostic performance of MR imaging of the colon may be better than that of MDCT for identifying high-risk stage II or stage III cases. Particularly, colon MRI reduced the false-positive rate and improved the interreader agreement, although further studies with a larger sample size are required.

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.

Rectal Cancer in 2018: A Primer for the Gastroenterologist

The rectum has distinctive anatomic and physiologic features, which increase the risk of local spread and recurrence among rectal cancers as compared to colon cancers. Essential to the management of rectal cancers is accurate endoscopic localization as well as preoperative imaging assessment of local and distant disease. Successful oncologic care is multidisciplinary including input from Gastroenterologists, Surgeons, Medical and Radiation Oncologists, Radiologists, and Pathologists. Extensive planning of curative intent is mandatory as failures of upfront treatment present great long‐term difficulty for patients and caregivers. Local recurrences are frequently associated with major morbidity including bowel and urinary obstruction, severe pain, and significantly diminished quality of life. Distant recurrence is associated with lower survival. Over the last two decades, there have been many advances in diagnostic imaging techniques as well as surgical techniques including transanal endoscopic microsurgery for very early stage cancers. Progress in curative management paradigms includes shorter courses of preoperative radiotherapy and chemotherapy doublet paradigms for perioperative treatment. This review describes the diagnosis, workup, and multimodality curative intent treatment of rectal cancers. It is emphasized that success begins in the hands and eyes of the gastroenterologist.

Consolidation mFOLFOX6 Chemotherapy After Chemoradiotherapy Improves Survival in Patients With Locally Advanced Rectal Cancer: Final Results of a Multicenter Phase II Trial

BACKGROUND

Adding modified FOLFOX6 (folinic acid, fluorouracil, and oxaliplatin) after chemoradiotherapy and lengthening the chemoradiotherapy-to-surgery interval is associated with an increase in the proportion of rectal cancer patients with a pathological complete response.

OBJECTIVE

The purpose of this study was to analyze disease-free and overall survival.

DESIGN

This was a nonrandomized phase II trial.

SETTINGS

The study was conducted at multiple institutions.

PATIENTS

Four sequential study groups with stage II or III rectal cancer were included.

INTERVENTION

All of the patients received 50 Gy of radiation with concurrent continuous infusion of fluorouracil for 5 weeks. Patients in each group received 0, 2, 4, or 6 cycles of modified FOLFOX6 after chemoradiation and before total mesorectal excision. Patients were recommended to receive adjuvant chemotherapy after surgery to complete a total of 8 cycles of modified FOLFOX6.

MAIN OUTCOME MEASURES

The trial was powered to detect differences in pathological complete response, which was reported previously. Disease-free and overall survival are the main outcomes for the current study.

RESULTS

Of 259 patients, 211 had a complete follow-up. Median follow-up was 59 months (range, 9-125 mo). The mean number of total chemotherapy cycles differed among the 4 groups (p = 0.002), because one third of patients in the group assigned to no preoperative FOLFOX did not receive any adjuvant chemotherapy. Disease-free survival was significantly associated with study group, ypTNM stage, and pathological complete response (p = 0.004, <0.001, and 0.001). A secondary analysis including only patients who received ≥1 cycle of FOLFOX still showed differences in survival between study groups (p = 0.03).

LIMITATIONS

The trial was not randomized and was not powered to show differences in survival. Survival data were not available for 19% of the patients.

CONCLUSIONS

Adding modified FOLFOX6 after chemoradiotherapy and before total mesorectal excision increases compliance with systemic chemotherapy and disease-free survival in patients with locally advanced rectal cancer. Neoadjuvant consolidation chemotherapy may have benefits beyond increasing pathological complete response rates. See Video Abstract at http://links.lww.com/DCR/A739.

Improved Stable Indocyanine Green (ICG)-Mediated Cancer Optotheranostics with Naturalized Hepatitis B Core Particles

In recent years, hepatitis B core protein virus-like particle (HBc VLP) is an impressive biomaterial, which has attracted considerable attention due to favorable properties such as structural stability, high uptake efficiency, and biocompatibility in biomedical applications. Heretofore, only a few attempts have been made to apply it in physical, chemical, and biological therapy for cancer. In this study, a tumor-targeting RGD-HBc VLP is first fabricated through genetic engineering. For image-guided cancer phototherapy, indocyanine green (ICG) is loaded into RGD-HBc VLP via a disassembly/reassembly pathway and electrostatic attraction with high efficiency. The self-assembled stable RGD-HBc VLP significantly improves body retention (fourfold longer), aqueous stability, and target specificity of ICG. Remarkably, these positive reformations promote more accurate and sensitive imaging of U87MG tumor, as well as prolonged tumor destruction in comparison with free ICG. Moreover, the photothermal and photodynamic effect on tumors are quantitatively differentiated by multiple linear regression analysis. Overall, less-potent medicinal ICG can be perfectly rescued by bioengineered HBc VLP to realize enhanced cancer optotheranostics.

Impact of RAS/BRAF mutation status in locally advanced rectal cancer treated with preoperative chemotherapy

PURPOSE

Our sincere hope is to establish the predictive factors of neoadjuvant chemotherapy (NAC) response and provide patients with greater certainty regarding treatment outcomes. The aim of this study was to assess the response to NAC and survival in patients with locally advanced rectal cancer (LARC) according to their RAS/BRAF mutation status.

METHODS

Data on 57 patients with LARC who received NAC between 2009 and 2016 were analyzed retrospectively. The patients were classified into two groups based on their mutation status: wild-type in both RAS and BRAF (WT) or mutant-type in either RAS or BRAF (MT).

RESULTS

Twenty-three patients were classified as WT, and the remaining 34 patients were MT. Histological response to NAC was similar in both groups. In responders, the 3-year relapse-free survival (RFS) was better compared with the non-responders (92 and 66%, respectively). In the WT group, the 3-year RFS was 95% which was significantly better than that in the MT group (59%, p = 0.011). The MT group was further subdivided into the following 2 groups by the pathological response; the MT responders (n = 10) and MT non-responders (n = 24). The 3-year RFS was 50% in the MT non-responders, which was significantly worse compared to that in the remaining patients (92%, p = 0.001).

CONCLUSION

RAS/BRAF mutations did not affect the response to NAC. However, the RFS was likely to be poor for those in the MT group who did not achieve favorable pathological response. In contrast, the RFS was favorable in the WT group regardless of the pathological response.