Adjuvant chemotherapy for rectal cancer patients treated with preoperative (chemo)radiotherapy and total mesorectal excision: a Dutch Colorectal Cancer Group (DCCG) randomized phase III trial

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.

Impact of Postoperative Adjuvant Chemotherapy Following Long-course Chemoradiotherapy in Stage II Rectal Cancer

OBJECTIVES

Use of adjuvant chemotherapy (AC) following neoadjuvant chemoradiation (nCRT) is controversial in rectal cancer (RC). We assessed a multi-institutional database to determine if there was benefit from AC for pathologic stage II RC patients and whether the addition of oxaliplatin to fluoropyrimidine (OXAC) therapy impacted outcomes.

MATERIALS AND METHODS

We included patients who underwent nCRT and had pathologic stage II (ypT3/4 ypN0) tumors. Disease-free survival and overall survival were assessed. Multivariate Cox models adjusting for age, sex, Eastern Cooperative Oncology Group, high-risk features (pT4, poor differentiation, <12 nodes removed, lymphovascular/perineural invasion, or obstruction/perforation), and clinical stage were constructed.

RESULTS

Of 485 patients, 73.6% received AC, of which 25.5% received OXAC. Patients receiving AC were younger (median age 61 vs. 64; P=0.003) and had higher rates of total mesorectal excision (81.5% vs. 78.9%; P=0.049), but had similar high-risk features, performance status, clinical stage, margin status, preoperative carcinoembryonic antigen, and nCRT regimen. In univariate analysis, overall survival was improved with fluoropyrimidine AC compared with no AC or OXAC (P=0.049), but not disease-free survival (P=0.33). In multivariate analysis, any AC, fluoropyrimidine AC, or OXAC did not improve outcomes. After stratifying patients by the presence of high-risk features, elevated carcinoembryonic antigen, margin status, or preoperative clinical stage, we did not identify a group with improved outcomes following AC.

CONCLUSIONS

In this multi-institutional cohort of yp stage II RC patients, we failed to identify a group that derives benefit from AC following nCRT. The addition of oxaliplatin did not appear to improve outcomes when compared with fluoropyrimidine alone.

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.

Phase II Trial of Neoadjuvant Chemotherapy, Chemoradiotherapy, and Laparoscopic Surgery with Selective Lateral Node Dissection for Poor-Risk Low Rectal Cancer

PURPOSE

The aim of this study is to evaluate the safety and efficacy of induction modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus bevacizumab followed by S- 1-based chemoradiotherapy in magnetic resonance imaging (MRI)-defined poor-risk locally advanced low rectal cancer.

PATIENTS AND METHODS

This was a prospective phase II trial at a single comprehensive cancer center. The primary endpoint was the pathological complete response (pCR) rate. Eligible patients had clinical stage II-III low rectal adenocarcinoma with any of the following MRI-defined poor-risk features: circumferential resection margin (CRM) ≤ 1 mm, cT4, positive lateral nodes, mesorectal N2 disease, and/or requiring abdominoperineal resection. Patients received six cycles of mFOLFOX6 with 5 mg/kg bevacizumab followed by oral S-1 (80 mg/m²/day on days 1-14 and 22-35) plus radiotherapy (50.4 Gy). Surgery was conducted through a laparoscopic approach. Lateral node dissection was selectively added when the patient had enlarged lateral nodes.

RESULTS

A total of 43 patients were enrolled. Grade 3-4 adverse events occurred in nine patients during induction chemotherapy and in five patients during chemoradiotherapy. One patient declined surgery with a clinical complete response. Forty-two patients underwent surgery, and 16 had pCR [37.2%, 95% confidence interval (CI) 24.4-52.1%]. All underwent R0 resection without conversion, including combined resection of adjacent structures (n = 14) and lateral node dissection (n = 30). Clavien-Dindo grade 3-4 complications occurred in six patients (14.3%). With median follow-up of 52 months, six developed recurrences (lung n = 5, local n = 1; 3-year relapse-free survival 86.0%).

CONCLUSIONS

This study achieved a high pCR rate with favorable toxicity and postoperative complications in poor-risk locally advanced low rectal cancer. Multicenter study is warranted to evaluate this regimen.

Feasibility of neoadjuvant therapy for elderly patients with locally advanced rectal cancer

PURPOSE

The feasibility of neoadjuvant therapy (NAT) for elderly patients with rectal cancer has not been evaluated well.

METHODS

Between 2004 and 2014, 506 patients with locally advanced low rectal cancer underwent curative resection. Fifty-four were over 75 years old (elderly group), and 452 were under 75 years old (young group). The patients were divided into sub-groups according to whether they received NAT.

RESULTS

Nineteen (35.2%) patients from the elderly group and 348 (77.0%) from the young group received NAT. The proportion of patients who received NAT was significantly lower in the elderly group. In the elderly group, the median age and prevalence of co-morbidities were significantly lower in patients with than in those without NAT. The incidence of severe adverse events was similar in the two groups. On multivariate analysis, age was not related to postoperative complications in patients who received NAT. The 5-year local recurrence rate was significantly lower in the elderly patients who received NAT, and similar to that of the young patients who received NAT.

CONCLUSIONS

Neoadjuvant therapy was feasible and should be considered as a treatment option for carefully selected elderly patients with locally advanced low rectal cancer.

Serial circulating tumour DNA analysis during multimodality treatment of locally advanced rectal cancer: a prospective biomarker study

OBJECTIVE

For patients with locally advanced rectal cancer (LARC), adjuvant chemotherapy selection following surgery remains a major clinical dilemma. Here, we investigated the ability of circulating tumour DNA (ctDNA) to improve risk stratification in patients with LARC.

DESIGN

We enrolled patients with LARC (T3/T4 and/or N+) planned for neoadjuvant chemoradiotherapy. Plasma samples were collected pretreatment, postchemoradiotherapy and 4-10 weeks after surgery. Somatic mutations in individual patient's tumour were identified via massively parallel sequencing of 15 genes commonly mutated in colorectal cancer. We then designed personalised assays to quantify ctDNA in plasma samples. Patients received adjuvant therapy at clinician discretion, blinded to the ctDNA results.

RESULTS

We analysed 462 serial plasma samples from 159 patients. ctDNA was detectable in 77%, 8.3% and 12% of pretreatment, postchemoradiotherapy and postsurgery plasma samples. Significantly worse recurrence-free survival was seen if ctDNA was detectable after chemoradiotherapy (HR 6.6; P<0.001) or after surgery (HR 13.0; P<0.001). The estimated 3-year recurrence-free survival was 33% for the postoperative ctDNA-positive patients and 87% for the postoperative ctDNA-negative patients. Postoperative ctDNA detection was predictive of recurrence irrespective of adjuvant chemotherapy use (chemotherapy: HR 10.0; P<0.001; without chemotherapy: HR 22.0; P<0.001). Postoperative ctDNA status remained an independent predictor of recurrence-free survival after adjusting for known clinicopathological risk factors (HR 6.0; P<0.001).

CONCLUSION

Postoperative ctDNA analysis stratifies patients with LARC into subsets that are either at very high or at low risk of recurrence, independent of conventional clinicopathological risk factors. ctDNA analysis could potentially be used to guide patient selection for adjuvant chemotherapy.

How to Achieve a Higher Pathologic Complete Response in Patients With Locally Advanced Rectal Cancer Who Receive Preoperative Chemoradiation Therapy

The current standard of care for treating patients with locally advanced rectal cancer includes preoperative chemoradiation therapy (PCRT) followed by a total mesorectal excision and postoperative adjuvant chemotherapy. A subset of these patients has achieved a pathologic complete response (pCR) and they have shown improved disease-free and overall survival compared to non-pCR patients. Thus, many efforts have been made to achieve a higher pCR through PCRT. In this review, results from various ongoing and recently completed clinical trials that are being or have been conducted with an aim to improve tumor response by modifying therapy will be discussed.

Clinical significance of soluble programmed cell death-1 and soluble programmed cell death-ligand 1 in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Background

Inhibition of the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) axis in combination with radiotherapy may be a promising approach to treat cancer. In the present study, we aimed to evaluate serum soluble PD-1/PD-L1 levels in patients with advanced rectal cancer treated with neoadjuvant chemoradiotherapy (CRT).

Methods

Serum soluble PD-L1 and PD-1 levels were measured using an enzyme-linked immunosorbent assay before and after CRT in 117 patients with low rectal cancer. Changes in the levels of sPD-L1/PD-1 after CRT, and the correlation between sPD-L1/PD-1 level and clinicopathological characteristics or disease-free survival (DFS) were evaluated.

Results

sPD-L1 levels significantly increased after CRT (p < 0.0001), whereas sPD-1 levels did not change significantly (p = 0.1050). High sPD-L1 before CRT was significantly associated with younger age (p = 0.044), and after CRT, with lymphovascular invasion (p = 0.021). High sPD-1 before and after CRT was significantly associated with a longer distance of the tumor from the anal verge (both p < 0.001). There was no correlation between sPD-L1 level and local PD-L1 expression on stromal immune cells. High sPD-L1 level after CRT tended to be associated with worse DFS (p = 0.0752). The multivariate analysis could not demonstrate an independent association for sPD-L1 levels after CRT with DFS.

Conclusions

Significant increase of sPD-L1 levels after CRT suggests that anti-PD-L1 therapy might be a potential treatment strategy in combination with CRT in advanced rectal cancer.

Early colorectal cancer: diagnosis, treatment and survivorship care

CRC is the third most commonly diagnosed malignancy and the fourth leading cause of cancer-related death in the world. With advances in treatment, colorectal cancer is being transformed from a deadly disease to an illness that is increasingly curable. With this transformation has come increased interest in the unique problems, risks, needs, and concerns of survivors who have completed treatment and are cancer-free. They often suffer late/long-term side effects of therapies that may compromise their QoL such as fatigue, sleep difficulty, fear of recurrence, anxiety, depression, negative body image, sensory neuropathy, gastrointestinal problems, urinary incontinence, and sexual dysfunction. In this review, we discuss what is known about early colorectal diagnosis, staging, treatments and their long-term effects on quality of life and survivorship care.

Significance of perineural and lymphovascular invasion in locally advanced rectal cancer treated by preoperative chemoradiotherapy and radical surgery: Can perineural invasion be an indication of adjuvant chemotherapy?

PURPOSE

To investigate the prognostic significance of lymphovascular space invasion (LVI) and perineural invasion (PNI) in rectal cancer.

METHODS AND MATERIALS

Clinical data of 1,232 stage II-III rectal cancer patients from six tertiary institutions were analyzed. All patients were treated by long-course preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME). Adjuvant systemic chemotherapy was performed for 962 (78.1%) patients according to the multidisciplinary team's decision. Treatment outcomes and prognostic factors were evaluated according to the lymphovascular invasion (LVI) and perineural invasion (PNI) status.

RESULTS

Five-year overall survival (OS) and recurrence-free survival (RFS) rates of the entire cohort were 84.1% and 71.1%, respectively. There is a significant difference in 5-year OS among both-absent, LVI+ only, PNI+ only, and both-present groups (89.1% vs. 77.9% vs. 67.6% vs. 56.2%; p < 0.001). RFS at five years was significantly different among both-absent, LVI+ only, PNI+ only, and both-present groups (78.7% vs. 58.7% vs. 44.6% vs. 38.6%; p < 0.001). The 5-year distant failure-free survival (DFFS) rate was also significantly different among four groups (84.6% vs. 61.4% vs. 54.2% vs 48.6%; p < 0.001). Although adjuvant chemotherapy did not affect 5-year DFFS in the entire cohort, adjuvant chemotherapy significantly reduced the distant failure rate in patients with PNI+ patients (44.9% vs. 54.6%, p = 0.048), not LVI+ patients (65.0% vs. 56.1%, p = 0.487).

CONCLUSION

Compared to LVI, PNI is a more significant prognostic factor in stage II-III rectal patients treated by preoperative CRT and TME surgery. The status of PNI rather than LVI could be an indicator for identifying patients who could benefit from adjuvant systemic chemotherapy.

Is adjuvant chemotherapy necessary for locally advanced rectal cancer patients with pathological complete response after neoadjuvant chemoradiotherapy and radical surgery? A systematic review and meta-analysis

PURPOSE

Current clinical guidelines recommended the routine use of adjuvant chemotherapy for locally advanced rectal cancer (LARC) patients. However, the effects of adjuvant chemotherapy in patients with pathological complete response (pCR) after neoadjuvant chemoradiotherapy and radical surgery showed discrepancies in different investigations.

METHODS

A systematic review and meta-analysis were conducted using PubMed, Embase and Web of Science databases. All original comparative studies published in English that were related to adjuvant versus non-adjuvant chemotherapy for LARC patients with pCR were included.

RESULTS

A total of 6 studies based on 18 centres or databases involving 2948 rectal cancer patients with pCR (adjuvant group = 1324, non-adjuvant group = 1624) were included in our overall analysis. Based on our meta-analysis, LARC patients with pCR who received adjuvant chemotherapy showed a significantly improved overall survival (OS) when compared to patients with observation (HR = 0.65, 95% CI = 0.46-0.90, P = 0.01). In addition, investigations focused on this issue based on the National Cancer Database (NCDB) were systematically reviewed in our current study. Evidence from all three analyses demonstrated that LARC patients with clinical nodal positive disease that achieved pCR might benefit the most from additional adjuvant chemotherapy.

CONCLUSION

Our meta-analysis indicated that adjuvant chemotherapy is associated with improved OS in LARC patients with pCR after neoadjuvant chemoradiotherapy and radical surgery.

Influence of Conversion and Anastomotic Leakage on Survival in Rectal Cancer Surgery; Retrospective Cross-sectional Study

BACKGROUND

Conversion and anastomotic leakage in colorectal cancer surgery have been suggested to have a negative impact on long-term oncologic outcomes. The aim of this study in a large Dutch national cohort was to analyze the influence of conversion and anastomotic leakage on long-term oncologic outcome in rectal cancer surgery.

METHODS

Patients were selected from a retrospective cross-sectional snapshot study. Patients with a benign lesion, distant metastasis, or unknown tumor or metastasis status were excluded. Overall (OS) and disease-free survival (DFS) were compared between laparoscopic, converted, and open surgery as well as between patients with and without anastomotic leakage.

RESULTS

Out of a database of 2095 patients, 638 patients were eligible for inclusion in the laparoscopic, 752 in the open, and 107 in the conversion group. A total of 746 patients met the inclusion criteria and underwent low anterior resection with primary anastomosis, including 106 (14.2%) with anastomotic leakage. OS and DFS were significantly shorter in the conversion compared to the laparoscopic group (p = 0.025 and p = 0.001, respectively) as well as in anastomotic leakage compared to patients without anastomotic leakage (p = 0.002 and p = 0.024, respectively). In multivariable analysis, anastomotic leakage was an independent predictor of OS (hazard ratio 2.167, 95% confidence interval 1.322-3.551) and DFS (1.592, 1077-2.353). Conversion was an independent predictor of DFS (1.525, 1.071-2.172), but not of OS.

CONCLUSION

Technical difficulties during laparoscopic rectal cancer surgery, as reflected by conversion, as well as anastomotic leakage have a negative prognostic impact, underlining the need to improve both aspects in rectal cancer surgery.

Cross-Sectional Study on MRI Restaging After Chemoradiotherapy and Interval to Surgery in Rectal Cancer: Influence on Short- and Long-Term Outcomes

Background

The time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic resonance imaging (MRI) and its impact on timing of surgery, and, second, to evaluate the impact of timing of surgery after chemoradiotherapy (CRT) on short- and long-term outcomes.

Methods

Patients were selected from a collaborative rectal cancer research project including 71 Dutch centres, and were subdivided into two groups according to time interval from the start of preoperative CRT to surgery (< 14 and ≥ 14 weeks).

Results

From 2095 registered patients, 475 patients received preoperative CRT. MRI restaging was performed in 79.4% of patients, with a median CRT–MRI interval of 10 weeks (interquartile range [IQR] 8–11) and a median MRI–surgery interval of 4 weeks (IQR 2–5). The CRT–surgery interval groups consisted of 224 (< 14 weeks) and 251 patients (≥ 14 weeks), and the long-interval group included a higher proportion of cT4 stage and multivisceral resection patients. Pathological complete response rate (n = 34 [15.2%] vs. n = 47 [18.7%], p = 0.305) and CRM involvement (9.7% vs. 15.9%, p = 0.145) did not significantly differ. Thirty-day surgical complications were similar (20.1% vs. 23.1%, p = 0.943), however no significant differences were found for local and distant recurrence rates, disease-free survival, and overall survival.

Conclusions

These real-life data, reflecting routine daily practice in The Netherlands, showed substantial variability in the use and timing of restaging MRI after preoperative CRT for rectal cancer, as well as time interval to surgery. Surgery before or after 14 weeks from the start of CRT resulted in similar short- and long-term outcomes.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-07097-7) contains supplementary material, which is available to authorized users.

Relationship of Red Blood Cell Distribution Width with Cancer Mortality in Hospital

Background

Red blood cell distribution width (RDW) is a clinical index used to make early diagnosis and to monitor treatment effects in iron deficiency anemia. Recently, several studies have suggested that RDW was associated with mortality from various cancers; however, there has been little evidence regarding RDW and cancer as a whole. Therefore, the purpose of our study was to investigate the relationship of RDW and overall cancer mortality in hospital.

Methods

We extracted patient data from the Multiparameter Intelligent Monitoring in Intensive Care Database III version 1.3 (MIMICIII.1.3). RDW was measured prior to hospital admission. Patients older than 18 who were diagnosed with malignant tumors were included. The primary outcome was cancer mortality in hospital. Logistic regression and multivariate analysis were used to assess the association between the RDW and hospital mortality.

Result

A total of 3384 eligible patients were enrolled. A positive correlation was observed between RDW and overall cancer mortality. Patients with higher RDW (14.4-16.3%, 16.4-30.5%) were at greater risk of death than the patients with RDW in the reference range (11.5-14.3%). On multivariate analysis, when adjusted for age and gender, the adjusted OR (95% CIs) in the mid-RDW group and high-RDW group were 1.61 (1.28, 2.03) and 2.52 (2.03, 3.13), respectively, with the low-RDW group set as the baseline. Similar trends were also observed in the model adjusted for other clinical characteristics. This suggested that elevated RDW was related to increased risk of cancer mortality, and RDW may play an important role in the prediction of short-term mortality after hospitalization in cancer patients.

Conclusion

Elevated RDW was associated with overall cancer mortality. To a certain extent, RDW may predict the risk of mortality in patients with cancers; it was an independent prognostic indicator of short-term mortality after hospitalization in cancer patients.

Total neoadjuvant treatment (CAPOX plus radiotherapy) for patients with locally advanced rectal cancer with high risk factors: A phase 2 trial

BACKGROUND AND PURPOSE

To evaluate the safety and efficacy of Total neoadjuvant treatment (TNT) in patients with rectal cancer with high risk factors.

METHODS AND MATERIALS

We did this phase 2 trial in patients who were diagnosed with stage II-III rectal cancer with at least one of the high risk factors. Three cycles of induction CAPOX were followed by pelvic radiotherapy of 50.4 Gy/28 fractions and two cycles of concurrent CAPOX. Three cycles of consolidation CAPOX were delivered after radiotherapy. Primary endpoints were pathological complete response (pCR) and R0 resection.

RESULTS

Fifty patients were enrolled and 47 patients were evaluable. A total of 34 patients (72.3%) completed 6 to 8 cycles of chemotherapy and 46 patients (98%) completed the planned radiotherapy. 17 patients (36%) achieved a pCR or clinical complete response (cCR). Three cCR patients (6.4%) refused the operation and selected a watch-and-wait approach. The most common grade 3 or worse adverse events were leucopenia (10.6%) and radiation dermatitis (6.4%). The major surgical complications included pelvic abscesses/infection in 2 patients (4.3%), anastomotic leakage and hemorrhage in1 patient (2.2%), respectively, which were all addressed with conservative management.

CONCLUSIONS

TNT is effective and safe in patients with locally advanced rectal cancer with high risk factors. Long-term efficacies of TNT need to be further evaluated. This trial is registered with Chinese Clinical Trial Registry, number ChiCTR-OIN-17012284.

Prognostic Value of the Cycle Number of Perioperative Chemotherapy in Locoregionally Advanced Rectal Cancer: a Propensity Score Matching Analysis

Background: Appropriate cycle number of perioperative chemotherapy for patients with locoregionally advanced rectal cancer (LARC) remains unknown. This study aimed to evaluate how cycle number of perioperative chemotherapy influenced the prognosis of LARC patients. Methodology / Principal Findings: In this study, a total of 388 consecutive patients were enrolled and retrospectively reviewed if they were diagnosed with untreated stage cII-III LARC and treated with neoadjuvant chemoradiotherapy plus radical surgery followed by adjuvant chemotherapy or not. After grouping by the postoperative pathologic stage (yp0-I vs. ypII-III), propensity score matching was performed in each group to balance baseline characteristics between the patients treated with chemotherapy cycle ≤ 7 and those treated with chemotherapy cycle ≥ 8. The chemotherapy cycle was analyzed for its association with the survivals of the matched patients in the 2 groups, respectively. And the incidence of treatment-related complications was also compared. Through analysis, chemotherapy cycle ≥ 8 appeared to predict better overall, disease-free and distant-metastasis-free survivals in the whole cohort of matched patients (P values were 0.003, 0.002 and 0.004, respectively) and the ypII-III group (P values were 0.006, 0.005 and 0.014, respectively). But in the yp0-I group, chemotherapy of 8 cycles or more brought no improvement of survivals but only more acute toxicities (83.5% vs. 57.0%, P < 0.001). Conclusions / Significance: Chemotherapy cycle ≥ 8 was proven associated with improved prognosis of LARC patients, especially those with ypII-III disease. But prolonged chemotherapy should be performed with caution in patients with yp0-I stage.

The potential benefit of adjuvant chemotherapy in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy is not predicted by tumor regression grade

INTRODUCTION

Recommended treatment for locally advanced rectal cancer (LARC) is neoadjuvant chemoradiotherapy (NACRT) followed by surgery and total mesorectal excision (TME). The role of adjuvant chemotherapy (ACT) in this regimen is still debated. Assessment of Dworak's tumor regression grade (TRG) after NACRT could potentially select patients who might benefit from ACT.

MATERIALS AND METHODS

Data for patients who underwent NACRT and TME for LARC between 2007 and 2014 were retrieved from the Bordet Institute database. Overall survival (OS) and disease-free survival (DFS) were calculated for the whole population, according to whether or not they received ACT, and according to TRG.

RESULTS

We included 74 patients (38 males) with a median age of 62.7 years (33-84 years). AJCC stage cIIIb disease was the most frequent (73%). Pathologic complete response (pCR) was achieved in 13 patients (17.6%). ACT was administered to 42 patients (56.8%). Five-year OS and DFS of patients who received ACT or not were 92 and 84.5% (p = ns), and 79.9 and 84.8% (p = ns), respectively. OS was related to TRG (cut-off value of 3) (p = 0.001). ACT administration was not correlated with improved outcomes in any TRG groups.

CONCLUSION

TRG is a prognostic factor for both OS and DFS but does not appear to have a significant benefit for the selection of patients with LARC treated with NACRT who might benefit from the administration of ACT. Prospective randomized trials with larger populations are needed to identify factors that predict which patients may benefit from the administration of ACT.

Adjuvant Chemotherapy in Rectal Cancer Patients Treated With Preoperative Chemoradiation and Total Mesorectal Excision: A Multicenter and Retrospective Propensity-Score Matching Study

PURPOSE

The role of adjuvant chemotherapy after preoperative chemoradiation therapy (CRT) and curative surgery in rectal cancer has yet to be definitely determined. We performed a retrospective and multicenter study to evaluate whether adjuvant chemotherapy (AC) could reduce recurrence and improve survival in locally advanced rectal cancer.

METHODS AND MATERIALS

We analyzed data from 8 tertiary institutions for 1442 patients with rectal cancer who underwent preoperative CRT and total mesorectal excision. Patients were classified into 2 groups: the AC group (patients who received chemotherapy after surgery) and the observation group (those who did not receive chemotherapy after surgery). Propensity-score matching was used to assess the exact role of AC. The AC group was then subdivided to investigate the impact of adding oxaliplatin to 5-fluorouracil (5-FU). Group 1 was treated with 5-FU/folinic acid or capecitabine without oxaliplatin, and group 2 received 5-FU/folinic acid or capecitabine with oxaliplatin.

RESULTS

The 3-year relapse-free survival rates in the AC and observation groups were 85.9% and 84.3%, respectively (P = .532). The 3-year overall survival rates in the AC and observation groups were 94.9% and 89.9%, respectively (P = .123). The rates of locoregional recurrence (2.2% vs 3.2%, P = .294) and distant metastasis (12.4% vs 12.9%, P = .927) at 3 years were not significantly different between the two groups. The 3-year relapse-free survival rates of group 1 and group 2 were 71.5% and 74.8%, respectively (P = .426). The 3-year overall survival rates of group 1 and group 2 were 89.9% and 96.5%, respectively (P = .102).

CONCLUSIONS

This multicenter study found insufficient evidence to support the use of 5-FU-based AC after preoperative CRT and curative surgery in rectal cancer.

Impact of Tumor Regression Grade as a Major Prognostic Factor in Locally Advanced Rectal Cancer after Neoadjuvant Chemoradiotherapy: A Proposal for a Modified Staging System

There is ongoing debate regarding the significance of complete or near-complete response after neoadjuvant chemoradiotherapy (CRT) for rectal cancer. This study assessed the prognostic value of the Dworak tumor regression grade (TRG) following neoadjuvant CRT and surgery primarily in patients with pathological stage (ypStage) II and III rectal cancer. The records of 331 patients who underwent neoadjuvant CRT followed by total mesorectal excision between 2004 and 2015 were retrospectively reviewed. Patients were categorized as having a good response (GR, TRG 3/4, n = 122) or a poor response (PR, TRG 1/2, n = 209). At a median follow-up of 65 months, five-year disease-free survival (DFS) was higher in the GR group than in the PR group (91.3% vs. 66.6%, p < 0.001). Patients with a GR and ypStage II disease had a five-year DFS that was indistinguishable from that of patients with ypStage 0–I disease (92.3% vs. 90.7%, p = 0.885). Likewise, patients with a GR and ypStage III disease had a five-year DFS similar to those with ypStage II disease (76.0% vs. 75.9%, p = 0.789). A new modified staging system that incorporates grouped TRG (GR vs. PR) was developed. The prognostic performance of this modified stage and the ypStage was compared with the Harrell C statistic. C statistic of the modified stage was higher than that of the ypStage (0.784 vs. 0.757, p = 0.012). The results remained robust after multivariate Cox regression analyses. In conclusion, a GR to neoadjuvant CRT is an independent predictor of good DFS and overall survival and further stratifies patients so as to estimate the risk of recurrence and survival among patients with ypStage II and III rectal cancer.

Optimal management of localized rectal cancer in older patients

In advising the optimal management for older patients, health care professionals try to balance the risks from frailty, vulnerability, and comorbidity against the patient's ultimate prognosis, potential functional outcomes and quality of life (QOL). At the same time it is important to involve the patient and incorporate their preferences. But how can we present and balance the potential downside of radical radiotherapy and risks of unsalvageable recurrence against the potential risks of postoperative morbidity and mortality associated with radical surgery? There are currently no nationally approved and evidence-based guidelines available to ensure consistency in discussions with older adults or frail and vulnerable patients. In this overview we hope to provide an insightful discussion of the relevant issues and options currently available.

Is adjuvant chemotherapy necessary for patients with ypT0-2N0 rectal cancer treated with neoadjuvant chemoradiotherapy and curative surgery?

Background and objective

The benefit from adjuvant chemotherapy for patients treated with neoadjuvant chemoradiotherapy (NCRT) and curative surgery remains controversial, particularly among those responding well to NCRT. This retrospective study aimed to clarify the benefits of adjuvant chemotherapy in terms of the oncological outcomes of patients with ypT0–2N0 rectal cancer after NCRT and curative surgery.

Methods

All patients with ypT0–2N0 rectal cancer after NCRT and curative resection between 2005 and 2014 were examined. The oncological outcomes between patients treated with adjuvant chemotherapy and those without any chemotherapy were compared.

Results

The clinicopathological characteristics of 110 patients were reviewed in this study; one patient was excluded due to lack of follow-up. Of the 109 patients included, 58 (53.2%) underwent adjuvant chemotherapy (chemo group), whereas the remaining 51 (46.8%) did not receive any chemotherapy (non-chemo group). After a median follow-up of 50 months, there were no significant differences in the 5-year overall survival (OS) or recurrence-free survival (RFS) rates between the groups (OS: 92.1 vs 86.3%, P = 0.375; RFS: 80.9 vs 74.7%, P = 0.534). Subgroup analysis also demonstrated no significant differences in 5-year OS and RFS rates between patients with ypT0N0 rectal cancer (P = 0.712 and P = 0.599, respectively) and those with ypT1–2N0 disease (P = 0.255 and P = 0.278, respectively).

Conclusions

These results indicate that patients with ypT0–2N0 rectal cancer after NCRT followed by curative surgery may not derive significant benefit from adjuvant chemotherapy. However, further prospective randomized trials, with larger sample sizes, are warranted to confirm this conclusion.

Impact of adjuvant chemotherapy on patients with ypT0-2 ypN0 rectal cancer after neoadjuvant chemoradiation: a cohort study from a tertiary referral hospital

Background

To investigate the importance of adjuvant chemotherapy in locally advanced rectal cancer (≥ cT3 or N+) staged ypT0–2 ypN0 on final histological work-up after neoadjuvant chemoradiation and radical resection.

Methods

The clinical course of patients with rectal cancer and ypT0–2 ypN0 stages after neoadjuvant chemoradiation and radical resection was analyzed from 1999 to 2012. Patients were divided into two groups depending on whether adjuvant chemotherapy was administered or not. Overall survival, distant metastases, and local recurrence were compared between both groups.

Results

Fifty-four patients with adjuvant (ACT) and 50 patients without adjuvant chemotherapy (NACT) after neoadjuvant chemoradiation followed by radical resection for rectal cancer were included in the analysis. Mean follow-up was 68 ± 33.7 months. One patient without adjuvant chemotherapy and none in the ACT group developed a local recurrence. Five patients in the NACT group and three patients in the ACT group had distant recurrences. Median disease-free survival for all patients was 65.5 ± 34.5 months. Multivariate analysis showed adjuvant chemotherapy to be the most relevant factor for disease-free and overall survival. Patients staged ypT2 ypN0 showed a significantly better disease-free survival after application of adjuvant chemotherapy. Disease-free survival in ypT0–1 ypN0 patients showed no correlation to the administration of adjuvant chemotherapy.

Conclusion

Administration of adjuvant chemotherapy after neoadjuvant chemoradiation and radical resection in rectal cancer improved disease-free and overall survival of patients with ypT0–2 ypN0 tumor stages in our study. In particular, ypT2 ypN0 patients seem to profit from adjuvant treatment.

The value of oxaliplatin in the systemic treatment of locally advanced rectal cancer

BACKGROUND

To evaluate, in a context of innovative multidisciplinary clinical practice, the efficacy of oxaliplatin in adjuvant administration (chemotherapy, CT) in relation to the total administered dose, in terms of prognosis with other clinical and therapeutic factors, in the heterogeneous model of locally advanced rectal cancer (LARC), which is characterized by a risk pattern of dominant systemic progression.

METHODS

Observational-analytical, retrospective, unicentric, non-randomized study of two cohorts of patients receiving FOLFOX-4 induction CT in neoadjuvancy, radiochemotherapy and surgery, differing in that one cohort did not receive any adjuvant post-surgical treatment and the other one received adjuvant CT with FOLFOX-4 cycles. A total of 212 patients from the Radiotherapy Oncology Service at the University Hospital Gregorio Marañon were studied: the neoadjuvant CT treatment group with oxaliplatin consisted of 110 patients and adjuvant CT treatment group with oxaliplatin consisted of 102 patients. The median follow-up time for the whole study population was 72 months (6 years).

RESULTS

The sociodemographic, clinical and diagnostic characteristics were very similar in both cohorts of patients, but with a pattern of therapeutic selection towards elements of adversity in pathological post-neoadjuvant staging. The dose of oxaliplatin in adjuvance (postoperative) superior to 6 cycles was positively associated with the locoregional control (LRC) at 5 years (P=0.012) and with the overall survival (OS) (P=0.048) at 5 years. In the responders to neoadjuvance with oxaliplatin [patients with tumor regression grade (TRG 3-4)], the dose of oxaliplatin greater than 5 cycles in adjuvance (postoperative) was positively associated with OS (P=0.06). And the dose of oxaliplatin in the range of 4-5 cycles in adjuvance (postoperative) was positively associated with distant metastasis-free survival (DMFS) and disease-free survival (DFS) in the cohort of responding patients (P=0.015 and 0.004, respectively).

CONCLUSIONS

The contribution of adjuvant oxaliplatin in the oncological evolution shows a favorable effect of LRC, DMFS, DFS and OS in the subgroups of patients that exhibit elements of response to neoadjuvant oxaliplatin (categories TRG 3-4, and pN0, downstaging T, downstaging N). Therefore, this neoadjuvant response profile with oxaliplatin, measured with highly reliable methodology (validated microscopic pathological response scales), defines a population of oxaliplatin-sensitive patients who benefits significantly from the administration of adjuvant oxaliplatin in sufficient cumulative doses (more of 5 cycles).

Circumferential resection margin as a prognostic factor after rectal cancer surgery: A large population-based retrospective study

AIM

This study aimed to investigate circumferential resection margin (CRM) as a prognostic factor for long-term oncologic survival after rectal cancer surgery.

METHODS

Patients diagnosed with malignant rectal cancer between 1 January 2010 and 31 December 2014, from the Surveillance, Epidemiology, and End Results (SEER) program were identified for this study. The patients were divided into five CRM groups to compare the baseline characteristics and assess cancer-specific survival (CSS): 0-1 mm, 1.1-2.0 mm, 2.1-5.0 mm, 5.1-10.0 mm, and >10 mm. The main endpoint was CSS.

RESULTS

Circumferential resection margin ≤1 mm was independently associated with 99% increased risk of cancer-specific mortality in rectal cancer [hazard ratio (HR) = 1.990, 95% confidence interval (CI) = 1.613-2.454, P < 0.001, using CRM (1.1-2.0 mm) as a reference]. CRM (5.1-10.0 mm) was independently associated with 29.2% decreased risk of cancer-specific mortality [HR = 0.708, 95% CI = 0.525-0.954, P = 0.152, using group (2.1-5.0 mm) as reference]. CRM ≤2 mm or ≤0.4 mm was not obviously associated with CSS.

CONCLUSIONS

circumferential resection margin is an independent prognostic factor in rectal cancer. Surgeons should try to maximize the CRM. Rectal cancer patients with CRM ≤1 mm should receive more postoperative attention depending on individual situation. Also, CRM should be accurately measured in millimeters in a preoperative magnetic resonance imaging or pathological report, rather than simply described as "involved" or "clear."

Nucleotide Excision Repair Factor XPC Ameliorates Prognosis by Increasing the Susceptibility of Human Colorectal Cancer to Chemotherapy and Ionizing Radiation

Nucleotide excision repair (NER) is a DNA damage repair mechanism in mammals, but the relationship between NER and human colorectal cancer (HRC) progression has not been clarified yet. In this study, the expression of the NER genes XPA, XPC, XPF, XPG, ERCC1, and XPD was measured in normal and cancerous human colorectal tissue. Among them, only the XPC gene expression was significantly increased in colorectal cancer tissue. To establish the role of XPC in colorectal cancer, small interference RNA (siRNA) targeting XPC was used to knockdown the expression of XPC in HRC cell lines. In addition, an expression vector plasmid containing the XPC cDNA was constructed and stably transfected into HRC cell lines to overexpress the XPC gene. Interestingly, MTT and apoptosis assay demonstrated that XPC gene overexpression significantly increased the susceptibility of HRC cell lines to cisplatin and X-ray radiation. In order to study the relationship between XPC expression and the progression of HRC, XPC expression was measured in 167 patients with colorectal cancer. The results showed that patients with high XPC expression had longer survival time. Cox regression analysis showed that high XPC expression might be a potential predictive factor for colorectal cancer. In conclusion, XPC plays a key role in the susceptibility of colorectal cancer to chemotherapy and ionizing radiation and is associated with a good patients' prognosis.

Potential of memory T cells in bridging preoperative chemoradiation and immunotherapy in rectal cancer

The management of locally advanced rectal cancer has passed a long way of developments, where total mesorectal excision and preoperative radiotherapy are crucial to secure clinical outcome. These and other aspects of multidisciplinary strategies are in-depth summarized in the literature, while our mini-review pursues a different goal. From an ethical and medical standpoint, we witness a delayed implementation of novel therapies given the cost/time consuming process of organizing randomized trials that would bridge an already excellent local control in cT3-4 node-positive disease with long-term survival. This unfortunate separation of clinical research and medical care provides a strong motivation to repurpose known pharmaceuticals that suit for treatment intensification with a focus on distant control. In the framework of on-going phase II-III IG/IMRT-SIB trials, we came across an intriguing translational observation that the ratio of circulating (protumor) myeloid-derived suppressor cells to (antitumor) central memory CD8+ T cells is drastically increased, a possible mechanism of tumor immuno-escape and spread. This finding prompts that restoring the CD45RO memory T-cell pool could be a part of integrated adjuvant interventions. Therefore, the immunocorrective potentials of modified IL-2 and the anti-diabetic drug metformin are thoroughly discussed in the context of tumor immunobiology, mTOR pathways and revised Warburg effect.

Is the accuracy of preoperative MRI stage in rectal adenocarcinoma influenced by tumour height?

AIM

To our knowledge, no prior studies have addressed the possible effects of tumour height on the accuracy of preoperative magnetic resonance imaging (MRI)-based staging relative to postoperative histopathological assessments in patients with adenocarcinoma of the rectum (RC). This study aimed to investigate whether the accuracy of preoperative MRI stage in RC is influenced by tumour height.

METHODS

A total of 489 consecutive RC patients scheduled for curative treatment between 2009 and 2013 were included. Of the 489 patients, 133 patients had preoperative chemoradiotherapy (CRT), and 356 patients underwent primary surgery. Low, mid and high RC were defined as a tumour <5 cm, 5-10 cm and >10 cm from the anal verge, respectively. Diagnostic MRI and, for patients with CRT, re-staging MRI features including tumour T-stage (mrT), distance between the tumour border and the distance to the mesorectal fascia (mrMRF), extramural tumour depth (mrEMD), extramural vascular invasion (mrEMVI) and nodal involvement (mrN) were correlated with the corresponding postoperative histopathological findings.

RESULTS

There were 115, 186 and 188 patients with low RC, mid RC and high RC, respectively. For all patients, the correlations between mrT and pT and between mrMRF and pCRM were not influenced by tumour height. None of the correlations between mrEMD, mrEMVI and mrN and the corresponding postoperative histopathological findings significantly differed for tumours of different heights. For patients with CRT, a remarkable proportion with low RC were overstaged as ymrT3 compared to ypT0-2.

CONCLUSIONS

The ability to preoperatively use MRI to accurately stage is not influenced by tumour height. For patients with preoperative CRT, low RC may be MRI overstaged due to post-radiation fibrosis. We found that mrEMD predicts pEMD reliably and should therefore be considered in treatment decisions. Although new MRI techniques are emerging, preoperative RC staging remains incompletely definitive in daily clinical practice.

A review of preoperative chemoradiotherapy for lower rectal cancer

In Western countries, rectal cancer has been treated by chemoradiotherapy (CRT) for several decades now, and good local control has been reported. However, Japanese guidelines did not strongly recommend CRT, because CRT is only useful for achieving local control and imbues no survival benefit. For this reason, CRT was rarely used to treat rectal cancer in Japan. However, in the 2000s, several studies involving CRT began to be reported from Western countries, such as “correlation between pathological complete response and survival,” “induction chemotherapy followed by CRT,” and “watch-and-wait policies.” These studies were directly correlated with survival of and benefits to the patients. Given these findings, Japanese institutions have recently begun to introduce CRT for rectal cancer. Therefore, in the present study, we reviewed several topics regarding CRT for rectal cancer.

Session 4: What should we do for poor responders after chemoradiotherapy: bad biology or should the fight go on?

Just over 50% of patients with advanced rectal cancer have a poor response to chemoradiotherapy with resultant poor outcomes. Professor Glimelius reviews the evidence base for defining such patients and the potential role, if any, of further treatment.

Adjuvant Chemotherapy Seemed Not to Have Survival Benefit in Rectal Cancer Patients with ypTis-2N0 After Preoperative Radiotherapy and Surgery from a Population-Based Propensity Score Analysis

BACKGROUND

Adjuvant chemotherapy is currently offered routinely, as standard, after radical resection for patients with rectal cancer receiving neo-adjuvant chemoradiation. However, the efficacy of adjuvant chemotherapy in patients with ypTis-2N0M0 has not been documented to the same extent, and the survival benefit remained controversial. The purpose of this work was to determine the role of chemotherapy in patients with ypTis-2N0M0 classification.

MATERIALS AND METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results database (n = 4,217). A propensity score model was utilized to balance baseline covariates.

RESULTS

Of the 4,217 included patients, 335 with ypTis-2N0M0 did not receive adjuvant chemotherapy. There were comparable cancer-specific survivals (CSS) between those undergoing adjuvant chemotherapy or not (log-rank test = 0.136, p = .712) in the overall sample. After propensity score matching, the cancer-specific survival did not differ between the chemotherapy and observation groups (log-rank test = 0.089, p = .765). Additionally, the Cox model did not demonstrate adjuvant chemotherapy as the prognostic factor, with hazard ratio = 0.95 (95% confidence interval 0.69-1.32) for CSS. Furthermore, the 10-year cumulative CSS was 78.7% and 79.4% between the chemotherapy and observation groups, indicating no significance, and no impact of adjuvant chemotherapy on survival was observed in different subgroups stratified by T stage, histological grade, histology, lymph nodes, and tumor size.

CONCLUSION

Patients with ypTis-2N0 rectal cancer did not benefit from adjuvant chemotherapy after preoperative radiology and radical surgery in this cohort study. These results provided new insight into the routine use of adjuvant chemotherapy for patients with rectal cancer with completed neo-adjuvant radiotherapy and curative surgery.

IMPLICATIONS FOR PRACTICE

Inconsistent recommendations for patients with rectal cancer receiving neo-adjuvant chemoradiation are offered by clinical guidelines. Adjuvant chemotherapy had no cancer-specific survival benefit, not only in the whole cohort, but also in the propensity score-matched cohort. A Cox model also confirmed adjuvant chemotherapy was not a significant prognostic factor in ypTis-2N0 rectal cancer. No survival benefit conferred by adjuvant chemotherapy was observed, regardless of whether T stage, histological type, grade, lymph nodes and tumor size varied.

Long-Term Outcome of Oxaliplatin and Capecitabine (XELOX) Concomitant with Neoadjuvant Radiotherapy and Extended to the Resting Period in High Risk Locally Advanced Rectal Cancer

Purpose: This study aimed at investigating the long-term outcomes of oxaliplatin and capecitabine (XELOX) administered concurrently with preoperative radiation and extended to the resting period in patients with high-risk locally advanced rectal cancer (LARC).

Methods: From January 2010 to December 2013, 45 patients were recruited. Study treatment consisted two cycles of XELOX regimen concomitant with preoperative radiation and then followed by an additional cycle of XELOX regimen between completion of neoadjuvant radiotherapy and surgery. Disease-free survival (DFS) time and overall survival (OS) time were analyzed.

Results: The median follow-up was 51 months. Twelve (26.7%) patients developed local recurrence or distant metastasis, including 10 (22.2%) patients developing distant metastasis only, 1 (2.2%) patient local recurrence only, and 1 (2.2%) patient both local recurrence and distant metastasis. The estimated 3-year DFS and OS was 75.5% (95% CI, 63.0%-88.0%) and 88.6% (95% CI, 98.0%-79.2%), respectively. Receiving adjuvant chemotherapy was a significant predictor for DFS, with hazard ratio 0.24 (95% CI: 0.08-0.74).

Conclusion: This intensified strategy with oxaliplatin and capecitabine (XELOX) administered concomitantly with neoadjuvant radiotherapy and then extended to the resting period in high-risk LARC patients is efficient. The long-term outcome is promising. Further study of this strategy is warranted.

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

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

Prognostic value of neoadjuvant treatment response in locally advanced rectal cancer

BACKGROUND

For locally advanced rectal cancer, response to neoadjuvant radiation has been associated with improved outcomes but has not been well characterized in general practice. The goals of this study were to describe disease response rates after neoadjuvant treatment and to evaluate the association between disease response and survival.

MATERIALS AND METHODS

Retrospective cohort study of patients aged 18-80 y with clinical stage II and III rectal adenocarcinoma in the National Cancer Database (2006-2012). All patients underwent radical resection after neoadjuvant treatment. Treatment responses were defined as follows: no tumor response; intermediate-T and/or N downstaging with residual disease; and complete-ypT0N0. Multivariable, multinomial regression was used to evaluate the association between neoadjuvant radiation use and disease response. Multivariable Cox regression was used to evaluate the association between disease response and overall risk of death.

RESULTS

Among 12,024 patients, 12% had a complete and 30% an intermediate response. Neoadjuvant chemotherapy alone was less likely to achieve an intermediate (relative risk ratio: 0.70 [0.56-0.88]) or a complete response (relative risk ratio: 0.59 [0.41-0.84]) relative to neoadjuvant radiation. Tumor response was associated with improved 5-y overall survival (complete = 90.2%, intermediate = 82.0%, no response = 70.5%; log-rank, P < 0.001). Complete and intermediate pathologic responses were associated with decreases in risk of death (hazard ratio: 0.40 [0.34-0.48] and 0.63 [0.57-0.69], respectively) compared to no response. Primary tumor and nodal response were independently associated with decreased risk of death.

CONCLUSIONS

Neoadjuvant radiation is associated with treatment response, and pathologic response is associated with improved survival. Pathologic response may be an early benchmark for the oncologic effectiveness of neoadjuvant treatment.

Prognostic markers of recurrence and survival in rectal cancer treated with neoadjuvant chemoradiotherapy and surgery

Aim: To identify markers of recurrence and survival in patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy and surgery. Materials & methods: A total of 280 patients were identified in Manitoba between 2007 and 2012. Demographics and clinical data were collected. Cox regression models were used to identify outcome predictors. Results: A total of 53 patients achieved pathological complete response (pCR) and 160 patients received adjuvant chemotherapy (ACT). The median follow-up duration was 2.06 years. Recurrence and survival rates at 5 years were 33.2 and 77.0%, respectively. pCR and lymphovascular invasion predicted recurrence. pCR and ACT predicted better survival. Conclusion: pCR is a significant predictor of recurrence and survival and may be considered as an oncological end point. The patients who achieve pCR may not derive additional survival benefit from ACT.

Role of Chemotherapy in the Neoadjuvant/Adjuvant Setting for Patients With Rectal Adenocarcinoma Undergoing Chemoradiotherapy and Surgery or Radiotherapy and Surgery

Rectal cancer has been successfully managed in the last couple of decades. In the USA, as the initial approach, neoadjuvant concurrent chemoradiation has been associated not only with decrease in tumor size and recurrence but also with higher resection rate with minimal side effects. Data support that addition of chemotherapy to radiotherapy is superior to radiotherapy alone in the neoadjuvant setting. Recent debates have addressed the question of administration of adjuvant chemotherapy following surgery. In this article, we discuss the role of chemotherapy in both the neoadjuvant and the adjuvant settings for locally advanced rectal cancer.

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.

Perineural Invasion Predicts for Distant Metastasis in Locally Advanced Rectal Cancer Treated With Neoadjuvant Chemoradiation and Surgery

OBJECTIVES

The benefit of adjuvant chemotherapy in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT) and surgery is controversial. We examined the association of perineural invasion (PNI) with outcomes to determine whether PNI could be used to risk-stratify patients.

MATERIALS AND METHODS

We performed a retrospective study of 110 patients treated with nCRT and surgery for LARC at our institution from 2004 to 2011. Eighty-seven patients were identified in our final analysis. We evaluated the association of PNI with locoregional control, distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival, using log-rank and Cox proportional hazard modeling.

RESULTS

Fourteen patients (16%) were PNI+ and 73 patients (84%) were PNI-. The median follow-up was 27 months (range, 0.9 to 84 mo). The median DMFS was 13.5 months for PNI+ and median not reached (>40 mo) for PNI- (P<0.0001). The median DFS was 13.5 months for PNI+ and 39.8 months for PNI- (P<0.0001). In a multivariate model including 7 pathologic variables, type of surgery, time to surgery from end of nCRT, and use of adjuvant chemotherapy, PNI remained a significant independent predictor of DMFS (hazard ratio 9.79; 95% confidence interval, 3.48-27.53; P<0.0001) and DFS (hazard ratio 5.72; 95% confidence interval, 2.2-14.9; P=0.0001).

CONCLUSIONS

For patients with LARC treated with nCRT, PNI found at the time of surgery is significantly associated with worse DMFS and DFS. Our data support testing the role of adjuvant chemotherapy in patients with PNI and perhaps other high-risk features.

Are pathological high-risk features in locally advanced rectal cancer a useful selection tool for adjuvant chemotherapy?

BACKGROUND

Several histological high-risk factors are used as an indication for adjuvant therapy in stage II colon cancer. Those and other factors, including lymphatic invasion, perineural invasion (PNI), venous invasion and tumour budding are associated with decreased outcome. In this study, we evaluated the prognostic and predictive values of these biomarkers in a cohort of rectal cancer patients.

MATERIALS AND METHODS

The trial-based cohort consisted of 221npTNM stage II-III rectal cancer patients, included in the PROCTOR/SCRIPT trial, a multicentre randomised phase III trial. Patients treated with neoadjuvant radiotherapy and TME surgery were randomised between adjuvant chemotherapy or observation. Lymphatic invasion, PNI, extramural venous invasion, intramural venous invasion and tumour budding were determined in standard tissue slides.

RESULTS

The presence of PNI (HR 3.36; 95% CI 1.82-6.21), extramural vascular invasion (HR 1.93; 95% CI 1.17-3.19) and tumour budding (HR 1.83, 95% CI 1.11-3.03) was associated with a significant worse overall survival. The presence of ≥2 adverse biomarkers resulted in a stronger prediction of adverse outcome in terms of overall survival (HR 2.82; 95% CI 1.66-4.79), disease-free survival (HR 2.27; 95% CI 1.47-3.48), and distant recurrence (HR 2.51; 95% CI 1.56-4.02). None of these markers alone or combined predicted a beneficial effect of adjuvant chemotherapy.

DISCUSSION

We confirmed that several stage-independent biomarkers were significantly associated with a decreased outcome in rectal cancer patients. More importantly, these markers did not have predictive value and are thus not useful to select for adjuvant therapy in rectal cancer.

Personalizing Adjuvant Therapy for Stage II/III Colorectal Cancer

This review focuses on three areas of interest with respect to the treatment of stage II and III colon and rectal cancer, including (1) tailoring adjuvant therapy for the geriatric population, (2) the controversy as to the optimal adjuvant therapy strategy for patients with locoregional rectal cancer and for patients with colorectal resectable metastatic disease, and (3) discussion of the microenvironment, molecular profiling, and the future of adjuvant therapy. It has become evident that age is the strongest predictive factor for receipt of adjuvant chemotherapy, duration of treatment, and risk of treatment-related toxicity. Although incorporating adjuvant chemotherapy for patients who have received neoadjuvant chemoradiation and surgery would appear to be a reasonable strategy to improve survivorship as an extrapolation from stage III colon cancer adjuvant trials, attempts at defining the optimal rectal cancer population that would benefit from adjuvant therapy remain elusive. Similarly, the role of adjuvant chemotherapy for patients after resection of metastatic colorectal cancer has not been clearly defined because of very limited data to provide guidance. An understanding of the biologic hallmarks and drivers of metastatic spread as well as the micrometastatic environment is expected to translate into therapeutic strategies tailored to select patients. The identification of actionable targets in mesenchymal tumors is of major interest.

Early Postoperative Low Expression of RAD50 in Rectal Cancer Patients Associates with Disease-Free Survival

BACKGROUND

Molecular biomarkers have the potential to predict response to the treatment of rectal cancer. In this study, we aimed to evaluate the prognostic and clinicopathological implication of RAD50 (DNA repair protein RAD50 homolog) expression in rectal cancer.

METHODS

A total of 266 rectal cancer patients who underwent surgery and received chemo- and radiotherapy between 2000 and 2011 were involved in the study. Postoperative RAD50 expression was determined by immunohistochemistry in surgical samples (n = 266).

RESULTS

Using Kaplan-Meier survival analysis, we found that low RAD50 expression in postoperative samples was associated with worse disease free survival (p = 0.001) and overall survival (p < 0.001) in early stage/low-grade tumors. In a comparison of patients with low vs. high RAD50 expression, we found that low levels of postoperative RAD50 expression in rectal cancer tissues were significantly associated with perineural invasion (p = 0.002).

CONCLUSION

Expression of RAD50 in rectal cancer may serve as a prognostic biomarker for long-term survival of patients with perineural invasion-positive tumors and for potential use in early stage and low-grade rectal cancer assessment.

Neoadjuvant Strategies: Locally Advanced Rectal Cancer

Colorectal cancer is one of the major leading causes of death in both men and women. The successful management of colon or rectal cancer demands a multidisciplinary approach. In the last few years, significant improvement has been noticed in the management of localized rectal cancer to reduce local recurrence and obtain complete pathological response following appropriate surgical steps, if necessary. Implementation of neoadjuvant therapy not only enhances disease control, it may also ensure sphincter preserving procedures or organ-preserving options. This article principally concentrates on the current neoadjuvant treatment for locally advanced rectal cancer and the prognostic outcomes of such therapy, including a discussion on the historical perspective.

T3 subclassification using the EMD/mesorectum ratio predicts neoadjuvant chemoradiation outcome in T3 rectal cancer patients

OBJECTIVE

To evaluate the feasibility of the EMD (extramural depth)/mesorectum ratio as a marker for T3 rectal cancer and its ability to predict tumour response to neoadjuvant chemoradiation and survival.

METHODS

From 2010 to 2016, 284 T3 rectal cancer patients who underwent high resolution MRI before neoadjuvant chemoradiation were enrolled. The EMD was defined as the distance from the outer edge of the muscularis propria to the outermost edge of the tumour. The measurement of the tumour EMD and mesorectum was in the same layer and their ratio was calculated. Receiver operating characteristic analysis and relative area under the curve statistics were used to choose the cut-off value. The association of the EMD/mesorectum ratio and other MRI or clinical factors with the tumour regression grade (TRG) was analysed. Cox regression analysis was used to estimate independent risk factors for disease-free survival (DFS) and overall survival (OS).

RESULTS

The mean EMD/mesorectum ratio was 0.47 ± 0.3. We chose an EMD/mesorectum ratio of 0.5 in further analyses after receiver operating characteristic analysis. Of 284 patients, 177 (62.3%) had an EMD/mesorectum ratio ≤ 0.5. Patients with an EMD/mesorectum ratio ≤ 0.5 had a higher TRG 0-1 rate than patients with a ratio >0.5 (53.1% vs 36.4%, p = 0.006). A multivariate analysis identified that an EMD/mesorectum ratio >0.5 [hazard ratio (HR) 2.020; p = 0.028] and ypTNM II-III (HR 3.550; p = 0.017) were independent prognostic factors to indicate decreased DFS. For OS, only patients with TRG 2-3 had decreased OS compared with patients with TRG 0-1 (HR 2.959; p = 0.035).

CONCLUSION

When the EMD/mesorectum ratio was applied to categorize T3 rectal cancer patients, the ratio of 0.5 can be used as a cut-off value for T3 rectal cancer. Patients with a ratio ≤ 0.5 had a higher response rate and better DFS. However, further validation is needed in a larger sample of patients. Advances in knowledge: The EMD/mesorectum ratio may serve to predict tumour response to neoadjuvant chemoradiation and survival in T3 rectal cancer patients.

Randomized phase III trial comparing surgery alone to UFT + PSK for stage II rectal cancer (JFMC38 trial)

Background

We conducted a randomized phase III trial comparing tegafur/uracil (UFT) and Polysaccharide-K (PSK) to surgery alone in curatively resected stage II rectal cancer patients.

Methods

Patients were randomly assigned to receive either UFT and PSK or surgery alone in a 1:1 ratio with a minimization method to balance the treatment allocation. The primary end point of this study was the disease-free survival (DFS). The secondary end point was the overall survival (OS).

Results

From October 2011 to February 2013, 111 patients were registered from 62 institutions. The study was prematurely closed due to poor accrual after reaching 20% of its goal. The patients’ characteristics were similar between the UFT and PSK group and the surgery-alone group. The DFS rate was 76.0% at 3 years and 65.1% at 5 years in the UFT and PSK arm and 84.0% at 3 years and 77.2% at 5 years in the surgery-alone arm. The DFS was slightly worse in the UFT + PSK arm than in the surgery-alone arm, but the difference did not reach statistical significance (log rank p = 0.102). The OS rate was 100% at 3 years and 97.9% at 5 years in the UFT + PSK arm, while that was 100% at 3 years and 93.4% at 5 years in the surgery-alone arm. The OS was similar in the UFT + PSK arm and surgery-alone arm (p = 0.533).

Conclusion

The present study suggests that UFT and PSK are not attractive candidates to advance to the next phase III study because the DFS was slightly worse in the UFT and PSK arm than in the surgery-alone arm.