Phase III Study of Adjuvant Chemotherapy and Radiation Therapy Compared With Chemotherapy Alone in the Surgical Adjuvant Treatment of Colon Cancer: Results of Intergroup Protocol 0130

Study protocol of short-course radiotherapy combined with CAPOX and PD-1 inhibitor for locally advanced colon cancer: a randomised, prospective, multicentre, phase II trial (TORCH-C)

INTRODUCTION

The preliminary result of the TORCH trial has shown a promising complete response (CR) for managing locally advanced rectal cancer with neoadjuvant short-course radiotherapy (SCRT) combined with chemotherapy and PD-1 inhibitor. For locally advanced colon cancer (LACC) with bulky nodal disease and/or clinically T4, neoadjuvant chemotherapy followed by colectomy with en bloc removal of regional lymph nodes is the suggested treatment. However, the CR rate is less than 5%. TORCH-C will aim to investigate neoadjuvant SCRT combined with chemotherapy and PD-1 inhibitor in LACC.

METHODS AND ANALYSIS

TORCH-C is a randomised, prospective, multicentre, double-arm, open, phase II trial of SCRT combined with chemotherapy and immunotherapy in LACC with microsatellite stable (MSS) patients and cT4 or bulky nodes. Eligible patients will be identified by the multidisciplinary team. 120 patients will be randomised 1:1 to the intervention or control arm. The patients in the control arm will receive four cycles of capecitabine plus oxaliplatin (CAPOX). The patients in the intervention arm will receive SCRT, followed by four cycles of CAPOX and PD-1 inhibitor (serplulimab). Both arms will receive curative surgery, followed by four cycles of CAPOX. The primary endpoint is pathological complete regression.TORCH-C (TORCH-colon) trial aims to investigate whether the combination of immunotherapy and chemoradiotherapy improves the treatment effect in LACC with MSS. TORCH-C will establish the TORCH platform, a key part of our long-term strategy to develop neoadjuvant treatment for colorectal cancer.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Fudan University Shanghai Cancer Center (approval number: 2211265-12).

TRIAL REGISTRATION NUMBER

NCT05732493.

Optimal treatment strategy and prognostic analysis for patients with non-metastatic pT4 colon adenocarcinoma

Objective

This study endeavored to explore the optimal treatment strategy and conduct a prognostic analysis for patients diagnosed with pT4M0 (pathologic stage T4) colon adenocarcinoma (COAD).

Methods and materials

A total of 8,843 patients diagnosed with pT4M0 COAD between January 2010 and December 2015 were included in this study from the Surveillance, Epidemiology, and End Results (SEER) database. These patients were randomly divided into a training set and an internal validation set using a 7:3 ratio. Variables that demonstrated statistical significance (P<0.05) in univariate COX regression analysis or held clinical significance were incorporated into the multivariate COX regression model. Subsequently, this model was utilized to formulate a nomogram. The predictive accuracy and discriminability of the nomogram were assessed using the C-index, area under the curve (AUC), and calibration curves. Decision curve analysis (DCA) was conducted to confirm the clinical validity of the model.

Results

In the entire SEER cohort, the 3-year overall survival (OS) rate (74.22% vs. 63.20%, P<0.001) and the 3-year cancer-specific survival (CSS) rate (76.25% vs. 66.98%, P<0.001) in the surgery combined with postoperative adjuvant therapy (S+ADT) group surpassed those in the surgery (S) group. Multivariate COX regression analysis of the training set unveiled correlations between age, race, N stage, serum CEA (carcinoembryonic antigen), differentiation, number of resected lymph nodes, and treatment modalities with OS and CSS. Nomograms for OS and CSS were meticulously crafted based on these variables, achieving C-indexes of 0.692 and 0.690 in the training set, respectively. The robust predictive ability of the nomogram was further affirmed through receiver operating characteristic (ROC) and calibration curves in both the training and validation sets.

Conclusion

In individuals diagnosed with pT4M0 COAD, the integration of surgery with adjuvant chemoradiotherapy demonstrated a substantial extension of long-term survival. The nomogram, which incorporated key factors such as age, race, differentiation, N stage, serum CEA level, tumor size, and the number of resected lymph nodes, stood as a dependable tool for predicting OS and CSS rates. This predictive model held promise in aiding clinicians by identifying high-risk patients and facilitating the development of personalized treatment plans.

Cone-beam computed tomography-guided online-adaptive radiotherapy for inoperable right colon cancer: First in human

We report the case of a medically inoperable patient with localised colon cancer. Due to symptomatic bleeding, definitive radiotherapy (5 daily fractions of 5 Gy) has been performed using cone-beam computed tomography-based online-adaptive radiotherapy (ART). Online-ART enables compensation of interfraction motion of abdominal organs by performing daily delineation of organs at risk (OARs) and target volumes. Daily treatment replanning maximised target volume coverage while lowering the dose to OARs. Intrafraction variation of the tumour was still significant and had to be incorporated in the planning target volume margin computation. After the treatment, the patient did not develop any acute radiotherapy-induced adverse events and had no further rectal bleeding either at the end of the radiotherapy or at oncological follow-up 4 months later. Online-ART for colon cancer is feasible and is a valuable alternative when surgery is not an option.

An Update on the Pivotal Roles of Probiotics, Their Components, and Metabolites in Preventing Colon Cancer

Diet, lifestyle, and gut microbiota composition are key risk factors for the progression of colon cancer. Probiotics are living microorganisms that can offer health benefits to the parasitifer when ingested in competent quantities. Several in vivo, in vitro, and clinical studies have demonstrated that probiotics can prevent and mitigate the development of colon cancer. The anti-colon cancer mechanisms of probiotics include the suppression of cell proliferation and the promotion of cancer cell apoptosis, immunomodulation, the modulation of intestinal microorganisms and their metabolism, strengthening the intestinal barrier, and antioxidant effects. This article describes the pathogenesis of colon cancer and the available therapeutic options. In addition, this paper reviews the mechanisms by which probiotics mitigate colon cancer as well as the mitigating effects of probiotic components and metabolites on colon cancer.

Pretreatment Carcinoembryonic Antigen Level Serves as a Potential Biomarker to Guide Adjuvant Radiotherapy in pT4N+ Colon Cancer Patients

The survival benefit of adjuvant radiotherapy in T4 colon cancer (CC) remains controversial, with conflicting results reported in the literature. This study aimed to explore the relationship between pretreatment carcinoembryonic antigen (CEA) level and overall survival (OS) of pT4N+ CC patients treated with adjuvant radiotherapy. Data of pT4N+ CC patients who received curative surgery between 2004 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The primary outcome was OS, and subgroup analysis was conducted according to pretreatment CEA level. A total of 8763 patients were eligible for our study. In the CEA-normal group, 151 patients received adjuvant radiotherapy, while 3932 patients did not. In the CEA-elevated group, 212 patients received adjuvant radiotherapy, while 4468 patients did not. In general, adjuvant radiotherapy was associated with better OS in pT4N+ CC patients (HR = 0.846, 95% CI = 0.733-0.976, P = 0.022). Intriguingly, only patients with an elevated pretreatment CEA level gained a survival benefit from adjuvant radiotherapy (HR = 0.782; 95% CI = 0.651-0.939; P = 0.008) while those with a normal pretreatment CEA level did not (HR = 0.907; 95% CI = 0.721-1.141; P = 0.403). Multivariable Cox regression analysis demonstrated that adjuvant radiotherapy was an independent protective factor in pT4N+ CC patients with an elevated pretreatment CEA level. Pretreatment CEA levels could serve as a potential biomarker to screen pT4N+ CC patients who would benefit from adjuvant radiotherapy.

Identifying the long-term survival beneficiary of chemotherapy for stage N1c sigmoid colon cancer

Sigmoid colon cancer often has an unsatisfactory prognosis. This study explored the effect of tumor deposits (TDs) on survival, and whether their presence/absence influence individualized treatment. Data of postoperative patients with sigmoid colon cancer were extracted from the Surveillance, Epidemiology, and End Results database. Overall survival (OS) was calculated using the Kaplan-Meier method and prognostic factors were identified using Cox regression analysis and random forest (RF). The nomogram's discrimination performance was evaluated using a concordance index (C-index), integrated discrimination improvement (IDI), calibration curves, and decision-curve analysis. The N1c group showed a worse prognosis than the N0 group. For N1c patients, a combination of surgery and chemotherapy prolonged survival, compared to surgery alone; however, the chemotherapy-surgery combination did not affect the OS of patients younger than 70 years, in stage T1-2, and/or of black race. Multivariable analysis and RF presented Age, T stage, and N stage were the most important predictors for OS. The novel nomogram had superiority to the TNM staging system with improved C-index and IDI, as well as good consistency and higher clinical benefit. TDs are associated with poor survival from sigmoid colon cancer, and considering TDs can inform the formulation of individual treatment regimens. The nomogram shows satisfactory prediction ability for OS.

Rectosigmoid Cancer-Rectal Cancer or Sigmoid Cancer?

OBJECTIVES

We aimed to determine the optimal treatment for patients with locally advanced rectosigmoid cancers, and to determine whether this can be guided by distance from anal verge (AV) and/or anatomic landmarks such as the sacral promontory and peritoneal reflection (PR).

MATERIALS AND METHODS

We retrospectively reviewed patients with T3-T4 and/or node-positive rectosigmoid cancers who underwent surgery from 2006 to 2018 with available pelvic imaging. We included tumors at 9 to 20 cm from the AV on either staging imaging, or colonoscopy. Patients were stratified into those who received neoadjuvant therapy, and those who underwent upfront surgery. Comparisons of characteristics were performed using χ 2 test and Fischer exact test. Locoregional failure (LRF) and overall survival were compared using Cox regressions and Kaplan-Meier analysis.

RESULTS

One hundred sixty-one patients were included. Ninety-seven patients had neoadjuvant therapy, and 64 patients had upfront surgery. Median follow-up time was 45.1 months. Patients who had neoadjuvant therapy had tumors that were higher cT stage ( P <0.01) with more positive/close circumferential resection margins seen on imaging by radiologists (28.9% vs. 1.6% , P =0.015). The 2-year rate of LRF, distant metastases, or overall survival was not significantly different between the 2 groups. None of 15 patients with tumors below the PR treated with neoadjuvant therapy had LRF, but 1 (25%) of 4 patients with tumors below the PR treated with adjuvant therapy experienced LRF ( P =0.05).

CONCLUSIONS

Patients with tumors below the PR may benefit more from neoadjuvant therapy. The PR on imaging may be a reliable landmark in addition to the distance from the AV to determine the most appropriate treatment option.

TXN inhibitor impedes radioresistance of colorectal cancer cells with decreased ALDH1L2 expression via TXN/NF-κB signaling pathway

Background

Colorectal cancer (CRC) is prevalent worldwide and is often challenged by treatment failure and recurrence due to resistance to radiotherapy. Here, we aimed to identify the elusive underlying molecular mechanisms of radioresistance in CRC.

Methods

Weighted gene co-expression network analysis was used to identify potential radiation-related genes. Colony formation and comet assays and multi-target single-hit survival and xenograft animal models were used to validate the results obtained from the bioinformatic analysis. Immunohistochemistry was performed to examine the clinical characteristics of ALDH1L2. Co-immunoprecipitation, immunofluorescence and flow cytometry were used to understand the molecular mechanisms underlying radioresistance.

Results

Bioinformatic analysis, in vitro, and in vivo experiments revealed that ALDH1L2 is a radiation-related gene, and a decrease in its expression induces radioresistance in CRC cells by inhibiting ROS-mediated apoptosis. Patients with low ALDH1L2 expression exhibit resistance to radiotherapy. Mechanistically, ALDH1L2 interacts with thioredoxin (TXN) and regulates the downstream NF-κB signaling pathway. PX-12, the TXN inhibitor, overcomes radioresistance due to decreased ALDH1L2.

Conclusions

Our results provide valuable insights into the potential role of ALDH1L2 in CRC radiotherapy. We propose that the simultaneous application of TXN inhibitors and radiotherapy would significantly ameliorate the clinical outcomes of patients with CRC having low ALDH1L2.

Postoperative locoregional recurrence pattern and treatment management of stage pT4 sigmoid colon cancer: a retrospective cohort study

BACKGROUND

This study aimed to explore the pattern of locoregional recurrence after surgery in patients with non-metastatic stage pT4 sigmoid colon cancer and the role of adjuvant radiotherapy on survival.

METHODS

We retrospectively analyzed data from 208 patients who underwent surgery in our hospital. The patients were randomly divided into training and validation groups at a 1:1 ratio. Patients at high risk for locoregional recurrence were screened using Cox regression analysis. Based on the data of 2,886 patients in the Surveillance, Epidemiology, and End Results (SEER) database, the effect of adjuvant radiotherapy on overall survival (OS) and cancer-specific survival (CSS) was evaluated by Kaplan-Meier curves.

RESULTS

Of the 208 patients, 57 (27.4%) presented with locoregional recurrences (14 anastomotic and 43 abdominal or pelvic lymph node recurrences). Multivariate analysis showed that serum CEA, differentiation, lymph node dissection number, and N stage were independent predictors of locoregional recurrence-free survival (all p < 0.05). A risk-stratification model was constructed, and a total score of ≥ 6.5 points was considered the high-risk group for locoregional recurrence. Both the training and validation sets presented that the model had a good predictive ability (area under the curve = 0.828 and 0.724, respectively). Analysis of SEER data revealed that adjuvant radiotherapy significantly prolonged OS and CSS in the high-risk population (all p < 0.05, vs. no radiotherapy).

CONCLUSIONS

Patients with a total risk score of 6.5 or more had a high likelihood of locoregional recurrence, and perhaps adjuvant radiotherapy could improve their survival.

Palliative Radiation Therapy without Chemotherapy for a Patient with Monomorphic Epitheliotropic Intestinal T Cell Lymphoma: A Case Report

Monomorphic epitheliotropic intestinal T cell lymphoma (MEITL), which used to be known as type 2 enteropathy-associated T cell lymphoma, is a rare lymphoma and is generally treated with chemotherapy. However, the MEITL prognosis is poor, and intestinal lymphoma including MEITL has the risk of bowel perforation not only at presentation but also during chemotherapy. A 67-year-old man was diagnosed with MEITL after presenting in our emergency room with bowel perforation. He and his family did not opt for the administration of anticancer drugs because of the risk of bowel perforation. However, they wanted the patient to receive palliative radiation therapy without chemotherapy. This treatment shrunk the tumor size without causing severe complications or decline in the quality of life, until he accidentally died due to traumatic intracranial hematoma. Considering the potential efficacy and safety of this treatment, it should be studied in more patients with MEITL.

Prognostic analysis and beneficiary identification of adjuvant external beam radiotherapy for stage pT4b sigmoid colon cancer

The clinical efficacy of adjuvant radiotherapy in sigmoid colon cancer remains questioned. To evaluate the clinical efficacy of adjuvant external beam radiotherapy (EBRT) for patients with pathologic stage T4b sigmoid colon cancer. Patients with stage pT4b sigmoid colon cancer receiving adjuvant EBRT or not followed by surgery between 2004 and 2016 were extracted from the Surveillance, Epidemiology, and End Results database. Analysis of overall survival (OS) was performed using Kaplan-Meier curves and prognostic factors were identified using Cox proportional hazards regression models with 95% confidence intervals within the entire cohort. A risk-stratification system was then developed based on the β regression coefficient. Among 2073 patients, 284 (13.7%) underwent adjuvant EBRT. The median OS in the group receiving adjuvant EBRT was significantly longer than that in the non-radiotherapy group (p < 0.001). Age, serum carcinoembryonic antigen (CEA) level, perineural invasion, lymph node dissection (LND) number, and adjuvant EBRT were independent factors associated with OS. A risk-stratification system was generated, which showed that low-risk patients had a higher 5-year survival rate than high-risk patients (75.6% vs. 42.3%, p < 0.001). Adjuvant EBRT significantly prolonged the 5-year survival rate of high-risk patients (62.6% vs. 38.3%, p = 0.009) but showed no survival benefit among low-risk patients (87.7% vs. 73.2%, p = 0.100). Our risk-stratification model comprising age, serum CEA, perineural invasion, and LND number predicted the outcomes of patients with stage pT4b sigmoid colon cancer based on which subgroup of high-risk patients should receive adjuvant EBRT.

Neoadjuvant chemoradiotherapy in patients with unresectable locally advanced sigmoid colon cancer: clinical feasibility and outcome

Background

Patients with locally advanced sigmoid colon cancer (LASCC) have limited treatment options and a dismal prognosis with poor quality of life. This retrospective study aimed to further evaluate the feasibility and efficacy of neoadjuvant chemoradiotherapy (NACRT) followed by surgery as treatment for select patients with unresectable LASCC.

Methods

We studied patients with unresectable LASCC who received NACRT between November 2010 and April 2019. The NACRT regimen consisted of intensity modulated radiotherapy (IMRT) of 50 Gy to the gross tumor and positive lymphoma node and 45 Gy to the clinical target volume. Capecitabine‑based chemotherapy was administered every 2 (mFOLFOX6) or 3 weeks (CAPEOX). Surgery was scheduled 6–8 weeks after radiotherapy.

Results

Seventy‑two patients were enrolled in this study. Patients had a regular follow-up (median, 41.1 months; range, 8.3–116.5 months). Seventy‑one patients completed NACRT, and sixty-five completed surgery. Resection with microscopically negative margins (R0 resection) was achieved in 64 patients (88.9%). Pathologic complete response was observed in 15 patients (23.1%), and multivisceral resection was necessary in 38 patients (58.3%). The cumulative probability of 3-year overall survival (OS) and progression-free survival (PFS) were 75.8 and 70.7%, respectively.

Conclusions

For patients with unresectable LASCC, neoadjuvant chemoradiotherapy is feasible, surgery can be performed safely and may result in increased survival and organ preservation rates.

Assessing the Effect of Radiotherapy in Addition to Surgery in Colon Adenocarcinomas: a Systematic Review and Meta-analysis of Contemporary Evidence

PURPOSE

This study aims to review the contemporary evidence investigating radiotherapy (RT) in addition to surgery for colon adenocarcinomas.

METHODS

We searched the following databases: PubMed, Science Direct, Scopus, ASCOpubs, the Cochrane Library, and Google Scholar. Studies (since January 2005) comparing outcomes of high-risk colon adenocarcinomas who underwent RT in addition to surgery versus no RT were eligible. Pooling of outcomes from published results or from analysis of survival curves was done. Subgroup analysis was conducted to determine if the efficacy of RT varies with RT timing.

RESULTS

Eight studies were included (five retrospective cohorts, three population-based studies). Pooled analysis from retrospective cohorts showed a reduction in 5-year LR (OR 0.41; 95% CI 0.21-0.79; p = 0.007) in the RT group. A benefit in 3-year (OR 1.81; 95% CI 1.15-2.87; p = 0.01) and 5-year (OR 2.10; 95% CI 1.21-3.63; p = 0.008) DFS and in 3-year (OR 2.55; 95% CI 1.43-4.54; p = 0.001) and 5-year (OR 2.00; 95% CI 1.17-3.41; p = 0.01) OS was seen in the RT group. The OS benefit was demonstrated in the subgroup analysis of neoadjuvant RT, but not with adjuvant RT. The improvement in OS with neoadjuvant RT was supported by a population-based study from NCDB, while results from two population-based studies investigating adjuvant RT were conflicting.

CONCLUSION

Taking into account the limitations of the studies, our review of evidence suggests a possible role of RT in improving oncologic outcomes of select colon adenocarcinomas. Prospective studies are needed to definitively assess the value of RT for colon cancer.

The survival benefit of adjuvant radiotherapy for pathological T4N2M0 colon cancer in the Modern Chemotherapy Era: evidence from the SEER database 2004-2015

Neoadjuvant chemoradiotherapy has been established as the standard treatment for patients with locally advanced rectal cancer. However, the role of radiotherapy (RT) has not been fully confirmed in advanced colon cancer (LACC). We postulated that patients with pathological T4N2 locally advanced colon cancer would benefit more from RT. 6715 pT4N2M0 colon cancer patients were included in the Surveillance, Epidemiology, and End Results (SEER) database. The primary endpoints were 5-year overall survival (OS) and cancer-specific survival (CSS). Propensity score matching (PSM) with Kaplan-Meier and Cox proportional hazards' models was performed to estimate prognosis. Before PSM, patients underwent RT had better OS and CSS as compared to patients did not receive RT (OS: 40.1% vs 27.6%, p < .001; CSS: 49.6% vs 41.1%, p = .002). After PSM, 239 matched pairs were formed for further analysis. RT group also presented significantly improved prognosis (OS: 40.1% vs 25.7%, p = .008; CSS: 49.6% vs 38.2%, p = .042). Multivariable Cox regression analysis showed that RT was a protective factor [OS：Hazard ratio (HR) =0.677, 95% Confidence interval (CI): 0.532-0.862, p = .002; CSS: HR = 0.708, 95% CI: 0.533-0.941, p = .018]. For pT4N2M0 colon cancer patients, the addition of RT seems to confer survival benefit as compared to patients who did not receive RT.

Surgery with and without adjuvant radiotherapy is associated with similar survival in T4 colon cancer

AIM

There is little evidence regarding the role of adjuvant radiotherapy for colon cancer. Despite this, national consensus guidelines recommend consideration of radiation for patients with T4 colon cancer. Large comparative studies may be beneficial in clarifying the potential benefit of postoperative radiation for this cohort.

METHOD

We compared the overall survival between patients treated with surgery with and without adjuvant radiation using the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results Program (SEER), as well as disease-specific survival using SEER. Cox proportional hazards models and propensity score matching were used to adjust for relevant confounders.

RESULTS

There were a total of 18 776 patients in the NCDB cohort and 9926 patients in the SEER cohort. After propensity score matching, there was no statistically significant difference in overall mortality between surgery with and without radiation in the NCDB [hazard ratio (HR) 1.11; 95% CI 0.93-1.31; P = 0.25] or in SEER (HR 1.20; 95% CI 0.84-1.72; P = 0.32). Additionally, using SEER, we found no statistically significant difference in disease-specific mortality between these two groups (HR 1.13; 95% CI 0.76-1.67; P = 0.54).

CONCLUSION

Using the NCDB and SEER, we found no statistically significant difference in overall survival or disease-specific survival between patients treated with and without adjuvant radiation. Further studies should evaluate the impact of adjuvant radiotherapy on local control and prevention of recurrence-related morbidity in patients with T4 colon cancer.

Lithium chloride increases sensitivity to photon irradiation treatment in primary mesenchymal colon cancer cells

Colorectal cancer (CRC) is the third most prevalent type of cancer worldwide. It is also the second most common cause of cancer-associated mortality; it accounted for about 9.2% of all cancer deaths in 2018, most of which were due to resistance to therapy. The main treatment for CRC is surgery, generally associated with chemotherapy, radiation therapy and combination therapy. However, while chemo-radiotherapy kills differentiated cancer cells, mesenchymal stem-like cells are resistant to this treatment, and this can give rise to therapy-resistant tumors. Our previous study isolated T88 primary colon cancer cells from a patient with sporadic colon cancer. These cells exhibited mesenchymal and epithelial features, high levels of epithelial-to-mesenchymal transition transcription factors, and stemness markers. In addition, it was revealed that lithium chloride (LiCl), a specific glycogen synthase kinase (GSK)-3β inhibitor, induced both the mesenchymal-to-epithelial transition and differentiation, and also reduced cell migration, stemness features and cell plasticity in these primary colon cancer cells. The aim of the present study was to investigate the effect of LiCl treatment on the viability of primary colon cancer cells exposed to 7 Gy delivered by high-energy photon beams, which corresponds to 6 megavolts of energy. To achieve this aim, the viability of irradiated T88 cells was compared with that of irradiated T88 cells pre-treated with LiCl. As expected, it was observed that LiCl sensitized primary colon cancer cells to high-energy photon irradiation treatment. Notably, the decrease in cell viability was greater with combined therapy than with irradiation alone. To explore the molecular basis of this response, the effect of LiCl on the expression of Bax, p53 and Survivin, which are proteins involved in the apoptotic mechanism and in death escape, was analyzed. The present study revealed that LiCl upregulated the expression of pro-apoptotic proteins and downregulated the expression of proteins involved in survival. These effects were enhanced by high-energy photon irradiation, suggesting that LiCl could be used to sensitize colon cancer cells to radiation therapy.

Utilization of Adjuvant Radiotherapy for Resected Colon Cancer and Its Effect on Outcome

BACKGROUND

Adjuvant radiation is generally not recommended for colon cancer but may be considered in certain clinical scenarios [advanced local disease (pT4) and/or positive margins]. Guidelines in this area are lacking; thus we analyzed the National Cancer Database (NCDB) for patterns of care in this regard and any predictors for outcome.

METHODS

We queried the NCDB from 2004 to 2016 for patients with resected adenocarcinoma of the colon having pT4 and/or had positive margins on final pathology and who received adjuvant multiagent chemotherapy. Multivariable logistic regression was used to identify predictors of adjuvant radiation. A propensity score was used to perform matched Kaplan-Meier analysis. Propensity-adjusted Cox regression was used to identify predictors of overall survival.

RESULTS

We identified 23,325 patients meeting criteria, of whom 1711 (7%) received adjuvant radiation. Median follow-up was 36 months. The majority of patients were pT4 alone (65%). Predictors of adjuvant radiation were lower comorbidity score, younger age, more remote year of treatment, and both pT4 and positive margins. Kaplan-Meier analysis revealed improved overall survival (OS) in patients with both pT4 and positive margins treated with radiation (median OS: 66 versus 47 months, p = 0.02). Receipt of adjuvant radiation was associated with improved OS [hazard ratio (HR): 0.86 (0.80-0.93) p = 0.0002] on Cox regression analysis. Increased age, higher comorbidity score, lower income, government insurance, and combined pT4/positive margins were indicative of worse survival.

CONCLUSIONS

Expectedly, adjuvant radiation use was relatively low but was associated with improved OS in patients with both pT4 and positive margins.

Postoperative Radiation for Pathologic Stage T4 Colon Cancers Receiving Adjuvant Chemotherapy

BACKGROUND

Previous small retrospective studies have suggested a benefit, mainly in preventing local recurrence, for postoperative radiation in nonmetastatic pathologic stage T4 colon cancers in patients who did not receive adjuvant chemotherapy. Current guidelines recommend postoperative radiation in nonmetastatic T4 colon cancers with penetration to a fixed structure, as well as for all patients with positive surgical margins. We aimed to assess the survival benefit of postoperative radiation in individuals with T4 colon cancers who received adjuvant chemotherapy.

METHODS

Using the National Cancer Data Base (2004-2014), we identified 20,967 and 5882 individuals with nonmetastatic pathologic stage T4 colon cancer treated with adjuvant chemotherapy who had negative or positive surgical margins, respectively. We used multivariate Cox regression to evaluate the effect of postoperative radiation on overall survival. In a secondary analysis, we stratified individuals according to chemotherapy intensity, pathologic N stage, and primary tumor location.

RESULTS

Postoperative radiation did not improve overall survival in individuals with positive surgical margins (hazard ratio = 1.05 [95% CI, 0.96-1.16]). This lack of survival benefit was noted regardless of chemotherapy regimen used, with adjusted hazard ratios of 1.11 (95% CI, 0.94-1.31) and 0.96 (0.85-1.09) for single-agent and doublet chemotherapy, respectively. Similarly, pathologic N stage and primary tumor location did not affect survival. In individuals with negative surgical margins, there was a detrimental effect for postoperative radiation, with an adjusted hazard ratio of 1.19 (95% CI, 1.10-1.29).

CONCLUSION

Postoperative radiation did not improve overall survival in individuals with pathologic stage T4 colon cancer who had either negative or positive surgical margins and who received adjuvant chemotherapy.

Adjuvant radiation therapy for T4 non-rectal colon adenocarcinoma provides a cause-specific survival advantage: A SEER database analysis

PURPOSE

While there is no level 1 evidence supporting the use of adjuvant radiotherapy (RT) for non-rectal colon cancer in the modern chemotherapy era, there are studies that suggest a local control benefit. This treatment modality is not part of standard treatment recommendations, and we hypothesized that adjuvant RT provides a benefit in locally advanced disease. Due to the limited number who receive post-operative RT, a national database was searched to provide sufficient power.

MATERIALS AND METHODS

A retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database was performed. Inclusion criteria were: non-rectal colon cancer, AJCC 6th or 7th edition T4 and M0, oncologic resection, and 1st cancer site. Patients were excluded for RT prior to or during surgery, or if the sequence of RT was unknown. Using a Cox proportional hazard model, the relative risk of cause-specific mortality for "RT after surgery" versus "No RT" was calculated.

RESULTS

21,789 patients were identified who met the inclusion criteria. Of these, only 1001 received adjuvant RT, and 64% were node-positive (53% RT vs. 65% no RT). When comparing RT vs. no RT, after adjusting for sex, age, N stage, and grade, we determined the relative risk of death from cancer was 0.8849 (95% CI: 0.8008-0.9779; p = 0.0165), suggesting that only 14 patients with T4 disease need receive adjuvant radiation to spare a cancer-related death.

CONCLUSIONS

Adjuvant RT is not routinely utilized for definitive treatment of T4 non-rectal colon cancer, but this analysis shows a significant cause-specific survival benefit.

Neoadjuvant Radiation Therapy in Locally Advanced Colon Cancer: a Cohort Analysis

BACKGROUND

A paucity of data exists in the use of neoadjuvant chemoradiation therapy (NRT) for T4, non-metastatic colon cancer. This study was conducted to determine the effect of NRT on outcomes after resection for T4 colon cancer.

METHODS

All patients with non-metastatic resected clinical T4 colon cancer from 2000 to 2012 at a tertiary care center were included. The cohort was divided into two groups-those that received NRT and those that did not (non-NRT). The primary outcomes were margin-negative resection and overall survival (OS).

RESULTS

One hundred and thirty-one consecutive patients with non-metastatic clinical T4 colon cancer with a mean age of 65 years were included. NRT was used in 23 patients (17.4%). NRT group was noted to have non-statistically significant improvement in R0 resection rate (NRT 95.7% vs non-NRT 88.0%; p = 0.27) and local recurrence (NRT 4.3% vs non-NRT 15.7%; p = 0.15). There was a significant difference in T-stage downstaging between the two groups (NRT 30.4% vs non-NRT 6.5%; p = 0.007). In a bivariate analysis, NRT was associated with improved 5-year OS (NRT 76.4% vs non-NRT 51.5%; p = 0.03). This relationship did not persist in a Cox proportional hazard analysis that included age and comorbidity (HR 2.19; 95% CI 0.87-5.52; p = 0.09).

CONCLUSIONS

The use of NRT in locally advanced T4 colon cancer is safe and associated with increased downstaging. While there was a trend toward improvement in local recurrence and the ability to obtain margin-negative resections in the NRT group, this was not significant. Significantly improved overall survival was not observed in a multivariable analysis.

Chemoprevention by Probiotics During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats

BACKGROUND

Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown.

AIM

To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats.

METHODS

The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 10¹⁰ cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats.

RESULTS

DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics.

CONCLUSION

The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis.

Prognostic significance of adjuvant radiation therapy in adenocarcinoma of the cecum

Purpose

Local recurrence is a common failure pattern in adenocarcinoma of the cecum. This study aimed to investigate the potential role of adjuvant radiation therapy on oncologic outcomes of patients with adenocarcinoma of the cecum.

Materials and Methods

This retrospective study was carried out at three large tertiary university hospitals. We analyzed the characteristics, prognostic factors, and survival of 162 patients with adenocarcinoma of the cecum that were treated and followed up between 2000 and 2013. All the patients had undergone a right hemicolectomy and received chemotherapy with (n = 48) or without (n = 114) adjuvant radiation therapy.

Results

The subjects were 65 females and 97 males with a median age of 56 years (range, 17 to 90 years) at diagnosis. The 5-year local control (LC), disease free survival (DFS), and overall survival (OS) rates were 72.7%, 57.2%, and 62.6% respectively. In a multivariate analysis, age, tumor stage, node stage, and adjuvant radiation therapy were determined to be independent prognostic factors. Age more than 55 years (hazard ratio [HR] = 1.0; 95% confidence interval [CI], 0.06–0.32; p = 0.003], T4 stage (HR = 6.8; 95% CI, 3.07–15.36; p < 0.001), node positive disease (HR = 4.2; 95% CI, 1.94–9.13; p < 0.001), and the absence of adjuvant radiation therapy (HR = 3.0; 95% CI, 1.39–6.46; p = 0.005) had a negative influence on OS.

Conclusion

Adjuvant radiation therapy significantly improves DFS and OS in patients with adenocarcinoma of the cecum.

Neoadjuvant FOLFOX chemotherapy combined with radiotherapy followed by radical resection in patients with locally advanced colon cancer

Background

Patients with locally advanced colon cancer (LACC) have a relatively poor prognosis despite radical resection and adjuvant chemotherapy. This study investigated the treatment efficacy and toxicity of neoadjuvant chemoradiotherapy in patients with LACC.

Methods

We retrospectively reviewed 36 patients with LACC preoperatively treated with chemotherapy and radiotherapy. Patients were administered chemoradiotherapy, which comprised radiotherapy and neoadjuvant chemotherapy involving a 5-fluorouracil, leucovorin, and oxaliplatin regimen every 2 weeks.

Results

Median age was 64 years (45–86 years) and median follow-up period was 23.5 months (5.0–49.1 months). Seven (19.4%) patients developed grade 3 or 4 adverse events during neoadjuvant concurrent chemoradiotherapy. Pathologic responses were not evaluated in two patients who did not undergo radical resection. Of the 34 patients who underwent surgery, nine (26.4%) achieved a pathologic complete response (pCR). The 2-year estimated overall survival and disease-free survival rates were 88.7% and 73.6%, respectively.

Conclusions

Our results demonstrated that neoadjuvant chemoradiotherapy is feasible and safe. A prominent pCR rate with an acceptable toxicity profile suggests that the multimodality therapy might be a treatment option for patients with LACC.

Comparison of futility monitoring guidelines using completed phase III oncology trials

BACKGROUND

Futility (inefficacy) interim monitoring is an important component in the conduct of phase III clinical trials, especially in life-threatening diseases. Desirable futility monitoring guidelines allow timely stopping if the new therapy is harmful or if it is unlikely to demonstrate to be sufficiently effective if the trial were to continue to its final analysis. There are a number of analytical approaches that are used to construct futility monitoring boundaries. The most common approaches are based on conditional power, sequential testing of the alternative hypothesis, or sequential confidence intervals. The resulting futility boundaries vary considerably with respect to the level of evidence required for recommending stopping the study.

PURPOSE

We evaluate the performance of commonly used methods using event histories from completed phase III clinical trials of the Radiation Therapy Oncology Group, Cancer and Leukemia Group B, and North Central Cancer Treatment Group.

METHODS

We considered published superiority phase III trials with survival endpoints initiated after 1990. There are 52 studies available for this analysis from different disease sites. Total sample size and maximum number of events (statistical information) for each study were calculated using protocol-specified effect size, type I and type II error rates. In addition to the common futility approaches, we considered a recently proposed linear inefficacy boundary approach with an early harm look followed by several lack-of-efficacy analyses. For each futility approach, interim test statistics were generated for three schedules with different analysis frequency, and early stopping was recommended if the interim result crossed a futility stopping boundary. For trials not demonstrating superiority, the impact of each rule is summarized as savings on sample size, study duration, and information time scales.

RESULTS

For negative studies, our results show that the futility approaches based on testing the alternative hypothesis and repeated confidence interval rules yielded less savings (compared to the other two rules). These boundaries are too conservative, especially during the first half of the study (<50% of information). The conditional power rules are too aggressive during the second half of the study (>50% of information) and may stop a trial even when there is a clinically meaningful treatment effect. The linear inefficacy boundary with three or more interim analyses provided the best results. For positive studies, we demonstrated that none of the futility rules would have stopped the trials.

CONCLUSION

The linear inefficacy boundary futility approach is attractive from statistical, clinical, and logistical standpoints in clinical trials evaluating new anti-cancer agents.

Intraoperative radiation therapy for colon and rectal cancers: a clinical review

Although there have been significant advances in the adjuvant therapy of colorectal cancer, results for patients have historically been poor when complete resection is unlikely or not possible. Similarly, locally recurrent colorectal cancer patients often experience significant tumor related morbidity and disease control and long term survival have historically been poor with standard therapies. Intraoperative radiation therapy (IORT) has been proposed as a possible tool for dose escalation in patients with locally advanced colorectal cancer.

For patients with locally advanced primary or recurrent colon cancer, the absence of prospective controlled trials limits the ability to draw definitive conclusions in completely resected patients. In subtotally resected patients, the available evidence is consistent with marked improvements in disease control and survival compared to historical controls. For patients with locally advanced primary or recurrent rectal cancer, a relatively large body of evidence suggests improved disease control and survival, especially in subtotally resected patients, with the addition of IORT to moderate dose external beam radiation (EBRT) and chemotherapy. The most important prognostic factor in nearly all series is the completeness of surgical resection. Many previously irradiated patients may be carefully re-treated with radiation and IORT in addition to chemotherapy resulting in long term survival in more than 25% of patients. Peripheral nerve is dose limiting for IORT and patients receiving 15 Gy or more are at higher risk.

IORT is a useful tool when dose escalation beyond EBRT tolerance limits is required for acceptable local control in patients with locally advanced primary or recurrent colorectal cancer. Previously irradiated patients should not be excluded from treatment consideration.

Outcomes of preoperative chemoradiotherapy followed by surgery in patients with unresectable locally advanced sigmoid colon cancer

BACKGROUND

Complete resection of locally advanced sigmoid colon cancer (LASCC) is sometimes difficult. Patients with LASCC have a dismal prognosis and poor quality of life, which has encouraged the evaluation of alternative multimodality treatments. This prospective study aimed to assess the feasibility and efficacy of neoadjuvant chemoradiotherapy (neoCRT) followed by surgery as treatment of selected patients with unresectable LASCC.

METHODS

We studied the patients with unresectable LASCC who received neoCRT followed by surgery between October 2010 and December 2012. The neoadjuvant regimen consisted of external-beam radiotherapy to 50 Gy and capecitabine-based chemotherapy every 3 weeks. Surgery was scheduled 6-8 weeks after radiotherapy.

RESULTS

Twenty-one patients were included in this study. The median follow-up was 42 months (range, 17-57 months). All patients completed neoCRT and surgery. Resection with microscopically negative margins (R0 resection) was achieved in 20 patients (95.2%). Pathologic complete response was observed in 8 patients (38.1%). Multivisceral resection was necessary in only 7 patients (33.3%). Two patients (9.5%) experienced grade 2 postoperative complications. No patients died within 30 days after surgery. For 18 patients with pathologic M0 (ypM0) disease, the cumulative probability of 3-year local recurrence-free survival, disease-free survival and overall survival was 100.0%, 88.9% and 100.0%, respectively. For all 21 patients, the cumulative probability of 3-year overall survival was 95.2% and bladder function was well preserved.

CONCLUSION

For patients with unresectable LASCC, preoperative chemoradiotherapy and surgery can be performed safely and may result in an increased survival rate.

Metastatic Colorectal Cancer Treatment and Survival: the Experience of Major Public Hospitals in South Australia Over Three Decades

BACKGROUND

Registry data from four major public hospitals indicate trends over three decades from 1980 to 2010 in treatment and survival from colorectal cancer with distant metastases at diagnosis (TNM stage IV).

MATERIALS AND METHODS

Kaplan-Meier product-limit estimates and Cox proportional hazards models for investigating disease-specific survival and multiple logistic regression analyses for indicating first-round treatment trends.

RESULTS

Two-year survivals increased from 10% for 1980-84 to 35% for 2005-10 diagnoses. Corresponding increases in five-year survivals were from 3% to 16%. Time-to-event risk of colorectal cancer death approximately halved (hazards ratio: 0.48 (0.40, 0.59) after adjusting for demographic factors, tumour differentiation, and primary sub-site. Survivals were not found to differ by place of residence, suggesting reasonable equity in service provision. About 74% of cases were treated surgically and this proportion increased over time. Proportions having systemic therapy and/or radiotherapy increased from 12% in 1980-84 to 61% for 2005-10. Radiotherapy was more common for rectal than colonic cases (39% vs 7% in 2005-10). Of the cases diagnosed in 2005-10 when less than 70 years of age, the percentage having radiotherapy and/or systemic therapy was 79% for colorectal, 74% for colon and 86% for rectum (and RS)) cancers. Corresponding proportions having: systemic therapies were 75%, 71% and 81% respectively; radiotherapy were 24%, 10% and 46% respectively; and surgery were 75%, 78% and 71% respectively. Based on survey data on uptake of offered therapies, it is likely that of these younger cases, 85% would have been offered systemic treatment and among rectum (and RS) cases, about 63% would have been offered radiotherapy.

CONCLUSIONS

Pronounced increases in survivals from metastatic colorectal cancer have occurred, in keeping with improved systemic therapies and surgical interventions. Use of radiotherapy and/or systemic therapy has increased markedly and patterns of change accord with clinical guideline recommendations.

Rapid diagnosis and staging of colorectal cancer via high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy of intact tissue biopsies

OBJECTIVE

To develop novel metabolite-based models for diagnosis and staging in colorectal cancer (CRC) using high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy.

BACKGROUND

Previous studies have demonstrated that cancer cells harbor unique metabolic characteristics relative to healthy counterparts. This study sought to characterize metabolic properties in CRC using HR-MAS NMR spectroscopy.

METHODS

Between November 2010 and January 2012, 44 consecutive patients with confirmed CRC were recruited to a prospective observational study. Fresh tissue samples were obtained from center of tumor and 5 cm from tumor margin from surgical resection specimens. Samples were run in duplicate where tissue volume permitted to compensate for anticipated sample heterogeneity. Samples were subjected to HR-MAS NMR spectroscopic profiling and acquired spectral data were imported into SIMCA and MATLAB statistical software packages for unsupervised and supervised multivariate analysis.

RESULTS

A total of 171 spectra were acquired (center of tumor, n = 88; 5 cm from tumor margin, n = 83). Cancer tissue contained significantly increased levels of lactate (P < 0.005), taurine (P < 0.005), and isoglutamine (P < 0.005) and decreased levels of lipids/triglycerides (P < 0.005) relative to healthy mucosa (R2Y = 0.94; Q2Y = 0.72; area under the curve, 0.98). Colon cancer samples (n = 49) contained higher levels of acetate (P < 0.005) and arginine (P < 0.005) and lower levels of lactate (P < 0.005) relative to rectal cancer samples (n = 39). In addition unique metabolic profiles were observed for tumors of differing T-stage.

CONCLUSIONS

HR-MAS NMR profiling demonstrates cancer-specific metabolic signatures in CRC and reveals metabolic differences between colonic and rectal cancers. In addition, this approach reveals that tumor metabolism undergoes modification during local tumor advancement, offering potential in future staging and therapeutic approaches.

Neo-adjuvant chemoradiotherapy and multivisceral resection to optimize R0 resection of locally recurrent adherent colon cancer

BACKGROUND

Neo-adjuvant chemoradiotherapy reduces local recurrence in rectal cancer, but there is a paucity of evidence regarding its role for colon cancer. The aim of this study was to evaluate the feasibility and outcomes of a neo-adjuvant chemoradiotherapy (NCRT) approach for locally recurrent adherent colon cancer (LRACC).

METHODS

All patients with non-metastatic LRACC treated with NCRT and multi-visceral resection (MVR) from January 2000 to July 2010 were included. The primary outcome was the rate of R0 resection (negative microscopic margins). Secondary outcomes were toxicities, post-operative morbidity and mortality, local recurrence, overall survival (OS) and disease-free survival (DFS).

RESULTS

Fifteen patients were identified. Nine primary cancers were located in the sigmoid and 4 in the left colon. Patients were treated with 45-50 Gy in 25 daily fractions and concurrent 5-FU infusion (225 mg/m(2)/day). En-bloc MVR included between 2 and 5 adjacent organs/structures. All but two resulted in R0 resection. One patient had a complete pathologic response and one had minimal residual tumour cells in the resected specimen. Post-operative major morbidity was 33.3%. No mortality occurred. At a median follow-up of 54 months, there were 2 local, 1 regional, and 2 distant lung recurrences. No grade 3 or 4 acute or late toxicities were observed. 5-year OS and DFS were 90.0% and 63.5% respectively.

CONCLUSIONS

NCRT followed by MVR is a feasible option for the treatment of highly selected LRACC to achieve R0 resection, while maintaining acceptable treatment toxicity. Short-term oncological results appear satisfactory, including good local control.

Neoadjuvant chemoradiotherapy and multivisceral resection for primary locally advanced adherent colon cancer: a single institution experience

BACKGROUND

Although there is an extensive body of literature on the role of neoadjuvant chemoradiotherapy (CRT) in the management of rectal cancer, its role in primary locally advanced adherent colon cancer (LAACC) is unclear.

OBJECTIVE

To analyzed the outcomes of neoadjuvant CRT and multivisceral resection in the management of LAACC patietns.

METHODS

We retrospectively reviewed our institutional Colorectal Carcinoma Database for 33 patients with potentially resectable, non-metastatic primary LAACC who received neoadjuvant CRT followed by multivisceral resection. CRT consisted of external beam radiation (45-50 Gy in 25 daily fractions) and concurrent 5-FU infusion (225 mg/m(2)/day).

RESULTS

There were 21 males and 12 females. Median age was 64 (31-83) and median follow-up was 36 months. All patients had microscopically clear resection margins (R0). Complete pathologic response was documented in 1 patient (3%) and 66% had ypT4b disease. Post-operative complications were observed in 36% of patients with no 30-day mortality. The 3-year overall survival and 3-year disease-free survival were 85.9% and 73.7% respectively. Two patients developed a local recurrence.

CONCLUSIONS

Neoadjuvant CRT and en-bloc multivisceral resection may result in high rates of R0 resection and excellent local control with acceptable morbidity and mortality in selected patients with LAACC.

Risk groups defined by Recursive Partitioning Analysis of patients with colorectal adenocarcinoma treated with colorectal resection

BACKGROUND

To define different prognostic groups of surgical colorectal adenocarcinoma patients derived from recursive partitioning analysis (RPA).

METHODS

Ten thousand four hundred ninety four patients with colorectal adenocarcinoma underwent colorectal resection from Taiwan Cancer Database during 2003 to 2005 were included in this study. Exclusion criteria included those patients with stage IV disease or without number information of lymph nodes. For the definition of risk groups, the method of classification and regression tree was performed. Main primary outcome was 5-year cancer-specific survival.

RESULTS

We identified six prognostic factors for cancer-specific survival, resulting in seven terminal nodes. Four risk groups were defined as following: Group 1 (mild risk, 1,698 patients), Group 2 (moderate risk, 3,129 patients), Group 3 (high risk, 4,605 patients) and Group 4 (very high risk, 1,062 patients). The 5-year cancer-specific survival for Group 1, 2, 3, and 4 was 86.6%, 62.7%, 55.9%, and 36.6%, respectively (p < 0.001). Hazard ratio of death was 2.13, 5.52 and 10.56 (95% confidence interval 1.74-2.60, 4.58-6.66 and 8.66-12.9, respectively) times for Group 2, 3, and 4 as compared to Group 1. The predictive capability of these grouping was also similar in terms of overall and progression-free survival.

CONCLUSION

The use of RPA offered an alternative grouping method that could predict the survival of patients who underwent surgery for colorectal adenocarcinoma.

Challenges in the management of stage II colon cancer

Approximately one third of patients diagnosed with early-stage colon cancer will present with lymph node involvement (stage III) and about one quarter with transmural bowel wall invasion but negative lymph nodes (stage II). Adjuvant chemotherapy targets micrometastatic disease to improve disease-free (DFS) and overall survival (OS). While beneficial for stage III patients, the role of adjuvant chemotherapy is unestablished in stage II disease. This likely relates to the improved outcome of these patients, and the difficulties in developing studies with sufficient power to document benefit in this patient population. However, recent investigation also suggests that molecular differences may exist between stage II and III cancers and within stage II patients. Validated pathologic prognostic markers are useful at identifying stage II patients at high risk for recurrence for whom the benefit from adjuvant chemotherapy may be greater. Such high-risk features include higher T stage (T4 v T3), suboptimal lymph node retrieval, presence of lymphovascular invasion, bowel obstruction, or bowel perforation, and poorly differentiated histology. However, for the majority of patients who do not carry any of these adverse features and are classified as "average-risk" stage II patients, the benefit of adjuvant chemotherapy remains unproven. Emerging understanding of the underlying biology of stage II colon cancer has identified molecular markers that may change this paradigm and improve our risk assessment and treatment choices for stage II disease. Assessment of microsatellite stability (MSI), which serves as a marker for DNA mismatch repair (MMR) system function, has emerged as a useful tool for risk stratification of patients with stage II colon cancer. Patients with high frequency of MSI have been shown to have increased OS and limited benefit from 5-fluorouracil (5-FU)-based chemotherapy. Additional research is necessary to clearly define the most appropriate way to use this marker and others in routine clinical practice.

A randomized phase III trial of adjuvant chemotherapy with irinotecan, leucovorin and fluorouracil versus leucovorin and fluorouracil for stage II and III colon cancer: a Hellenic Cooperative Oncology Group study

BACKGROUND

Colon cancer is a public health problem worldwide. Adjuvant chemotherapy after surgical resection for stage III colon cancer has been shown to improve both progression-free and overall survival, and is currently recommended as standard therapy. However, its value for patients with stage II disease remains controversial. When this study was designed 5-fluorouracil (5FU) plus leucovorin (LV) was standard adjuvant treatment for colon cancer. Irinotecan (CPT-11) is a topoisomerase I inhibitor with activity in metastatic disease. In this multicenter adjuvant phase III trial, we evaluated the addition of irinotecan to weekly 5FU plus LV in patients with stage II or III colon cancer.

METHODS

The study included 873 eligible patients. The treatment consisted of weekly administration of irinotecan 80 mg/m2 intravenously (i.v.), LV 200 mg/m2 and 5FU 450 mg/m2 bolus (Arm A) versus LV 200 mg/m2 and 5FU 500 mg/m2 i.v. bolus (Arm B). In Arm A, treatments were administered weekly for four consecutive weeks, followed by a two-week rest, for a total of six cycles, while in Arm B treatments were administered weekly for six consecutive weeks, followed by a two-week rest, for a total of four cycles. The primary end-point was disease-free survival (DFS) at three years.

RESULTS

The probability of overall survival (OS) at three years was 0.88 for patients in Arm A and 0.86 for those in Arm B, while the five-year OS probability was 0.78 and 0.76 for patients in Arm A and Arm B, respectively (P = 0.436). Furthermore, the probability of DFS at three years was 0.78 and 0.76 for patients in Arm A and Arm B, respectively (P = 0.334). With the exception of leucopenia and neutropenia, which were higher in patients in Arm A, there were no significant differences in Grades 3 and 4 toxicities between the two regimens. The most frequently recorded Grade 3/4 toxicity was diarrhea in both treatment arms.

CONCLUSIONS

Irinotecan added to weekly bolus 5FU plus LV did not result in improvement in disease-free or overall survival in stage II or III colon cancer, but did increase toxicity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12610000148077.

Surgical management of locally advanced and locally recurrent colon cancer

Locally advanced and locally recurrent colon cancers pose a surgical challenge with tumors extending into surrounding structures and organs. Anticipation of the need for an extended surgical resection, often with multivisceral en bloc organ removal, is critical for surgical planning. For both primary and recurrent tumors, postsurgical long-term survival is achievable but only after complete resection. The role of neoadjuvant and adjuvant therapy continues to be redefined in this era of biologic chemotherapeutics, and multimodality therapy holds promise in aiding resection and improving postsalvage survival.

Retrospective Long-Term Results and Prognostic Factors of Postoperative Treatment for UICC Stages II and III Rectal Cancer

Aims

To retrospectively evaluate 5-year local control, disease-free survival, cancer-specific survival and overall survival rates in patients with UICC stages II and III rectal cancer treated with adjuvant therapy and especially to analyze the impact of some prognostic factors on clinical outcome at univariate and multivariate analyses.

Methods and Materials

We retrospectively reviewed 306 patients treated with postoperative 5-fluorouracil-based chemoradiation (278 patients) or radiotherapy alone (28 patients) after curative surgery. The following prognostic factors were considered at univariate and multivariate analyses: age, sex, tumor location, surgery procedure, pathological stage, histology, tumor grade, surgical margins and radiotherapy technique.

Results

The 5-year actuarial rates for local control, disease-free survival, cancer-specific survival and overall survival were respectively 89.7%, 59.7%, 68.6% and 61.4% for the 278 patients (91%) treated with postoperative chemoradiation. Univariate analysis showed that abdominal-perineal resection impacted disease-free survival and that the T4 variable had an impact on cancer-specific survival and disease-free survival. Instead, age ≥70, N2, IIIB (p T3 p N1) and IIIC (pT3 p N2) stage impacted cancer-specific survival, disease-free survival and rate of distant metastases. Multivariate analysis showed as significant variables age ≥70 years, pN1 and pN2 and extraperitoneal tumor location.

Conclusions

Our retrospective study showed a good 5-year local control. Factors such as individual pT4, pN1, pN2, age ≥70 years, abdominal-perineal resection, stages IIIB-IIIC versus II-IIIA and extraperitoneal tumor location negatively influenced disease-free survival, distant metastases and cancer-specific survival. Differences exist between stages II and III rectal cancer and treatment modulation and intensification are required in order to offer the most appropriate and effective adjuvant treatment and to improve survival of rectal cancer patients.

External beam radiotherapy for colon cancer: patterns of care

PURPOSE

Despite its common and well characterized use in other gastrointestinal malignancies, little is known about radiotherapy (RT) use in nonmetastatic colon cancer in the United States. To address the paucity of data regarding RT use in colon cancer management, we examined the RT patterns of care in this patient population.

METHODS AND MATERIALS

Patients with nonmetastatic colon cancer, diagnosed between 1988 and 2005, were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate methods were used to identify factors associated with RT use.

RESULTS

On univariate analysis, tumor location, age, sex, race, T stage, N stage, and geographic location were each associated with differences in RT use (all p < 0.01). In general, younger patients, male patients, and patients with more advanced disease were more likely to receive RT. On multivariate analysis, tumor location, age, gender, T and N stage, time of diagnosis and geographic location were significantly associated with RT use (all p < 0.001). Race, however, was not associated with RT use. On multivariate analysis, patients diagnosed in 1988 were 2.5 times more likely to receive RT than those diagnosed in 2005 (p = 0.001). Temporal changes in RT use reflect a responsiveness to evolving evidence related to the therapeutic benefits of adjuvant RT.

CONCLUSIONS

External beam RT is infrequently used for colon cancer, and its use varies according to patient and tumor characteristics. RT use has declined markedly since the late 1980s; however, it continues to be used for nonmetastatic disease in a highly individualized manner.

Primary Mucinous Adenocarcinoma of Appendix Treated with Chemotherapy and Radiotherapy: A Case Report

A rare case of primary appendiceal mucinous adenocarcinoma is reported. The presenting signs and symptoms were suggestive of acute appendicitis. An appendectomy was performed resulting in a histological diagnosis of grade 2 mucinous adenocarcinoma of the appendix. The patient was referred to our clinic where he underwent a complementary right hemicolectomy with lymph node dissection. Two of the 17 resected lymph nodes were tumor positive but there was no residual tumor in the hemicolectomy specimen. The patient was staged as T4N1M0 and adjuvant multimodality treatment was planned because he was considered at high risk for local-regional recurrence and distant metastasis. Three cycles of capecitabine 1250 mg/m2 on days 1–14 and oxaliplatin 130 mg/m2 on day 1, every 21 days (CAPOX) were administered, then a total dose of 50.4 Gy external-beam radiation therapy was deliveredtothe primarytumor region and 45 Gy to the lymphatics, and finally3 further cycles of the CAPOX regimen were administered. Multimodality treatment was well tolerated by the patient, who is still alive 25 months after the hemicolectomy procedure with no evidence of disease progression.

Roles of probiotics and prebiotics in colon cancer prevention: Postulated mechanisms and in-vivo evidence

Probiotics are live bacteria that could exert health beneficial effects upon consumption. In additional to their conventional use as gut modulators, probiotics are investigated for their role to prevent cancer. In-vivo and molecular studies have demonstrated encouraging outcomes, mainly attributed to its antimicrobial effects against carcinogen-producing microorganisms, antimutagenic properties, and alteration of the tumor differentiation processes. Prebiotics are indigestible food components that could promote the growth of beneficial bacteria including probiotics. Present studies have suggested that prebiotics also possess protective effect against colon carcinogenesis, mainly attributed to the production of short chain fatty acids upon its fermentation by gut microflora, and alteration of gene-expressions in tumor cells. Synbiotic (combination of probiotic and prebiotic) has been found to exert a synergistic effect in improving colon carcinogenesis compared to when both were used individually. This paper highlights the colon cancer preventive effects by probiotics, prebiotics and synbiotics. In addition, the controversial outcomes on the insignificant effect of these food adjuncts will be discussed.

Successful downstaging of high rectal and recto-sigmoid cancer by neo-adjuvant chemo-radiotherapy

PURPOSE

The benefit of neoadjuvant therapy for tumours above the peritoneal reflection is not clear. The purpose of this study is to demonstrate the feasibility and downstaging of treating locally advanced tumours from high rectum to distal sigmoid with preoperative chemoradiotherapy (CRT).

METHODS AND MATERIALS

Seventeen patients with high rectal, rectosigmoid or distal sigmoid tumours above the peritoneal reflection received neoadjuvant CRT, selected on MRI findings indicating T4 disease or threatened circumferential resection margin. All patients were administered neoadjuvant chemotherapy, with Oxaliplatin or Mitomycin C and a Fluoropyrimidine. The pelvis received long-course CT-planned conformal RT, 45 Gy in 25 fractions, with a boost of 5.4-9 Gy in 3-5 fractions. Thirteen patients were treated with concomitant oral or intravenous Fluoropyrimidine chemotherapy.

RESULTS

Median follow-up was 37 months. Overall survival was 82.35% (95% Confidence Interval (CI) 54.7-93.9) and disease free survival 81.25% (95% CI 52.5-93.5). Only 1 patient suffered loco-regional relapse. Chemotherapy regimens were well tolerated, though some patients required dose reductions. Nine patients (52.9%) lowered pathologic disease AJCC stage, i.e. 'downstaged'. Six patients (35.3%) achieved complete pathological response. Clear margins were attained in all but 1 patient. Three patients were converted from cT4 to ypT3. No patient required a gap during CRT. One patient suffered a grade III acute toxicity, but no grade IV (RTOG). There were 3 grade III and 3 grade IV late toxicities (LENT-SOMA).

CONCLUSIONS

Locally advanced high rectal and recto-sigmoid tumours may be treated with pre-operative CRT with acceptable toxicity, impressive down-staging, and clear surgical margins.