Prognostic factors for disease-free survival in patients with T3–4 or N+ rectal cancer treated with preoperative chemoradiation therapy, surgery, and intraoperative irradiation

Post-Chemoradiation Metastatic, Persistent and Resistant Nodes in Locally Advanced Rectal Cancer: Metrics and Their Impact on Long-Term Outcome

BACKGROUND

The purpose of this study was to evaluate the long-term oncological progression pattern of locally advanced rectal cancer patients with post-neoadjuvant nodal metastatic disease (ypN+) and correlate potential prognostic features associated with proven radiochemoresistant nodal biology.

METHODS

Individual patient data (100 variables) from a 20-year consecutive single-institution multidisciplinary experience (1995-2015), delivering multimodal therapy to rectal cancer patient candidates for radical treatment, including a neoadjuvant component and surgical resection with or without intraoperative radiotherapy followed by optional adjuvant chemotherapy. The ypN+ disease data was registered in the context of initial staging categories post-neoadjuvant T status (ypT).

RESULTS

Data on 487 patients showed histologically confirmed diagnoses of metastatic nodal disease in 108 specimens (ypN+, 22.1). There was a significant age difference (p = 0.009) between the ypN groups: age ≥ 65 was 57.6% in pN0 and 43.5% in ypN+ and patients aged < 65 constituted 42.4% of pN0 and 56.5% of ypN+. According to the clinical stage there were statistically significant differences (p = 0.001) in the categories' distribution: ypN+ patients 10.8% were stage II and 89.2% were stage III. Univariant analysis on outcome variables showed statistically significant differences in overall survival at 7 years (63.8% vs. 55.7%, p = 0.016) disease-free survival (DFS) (78% vs. 53.8%, p = 0.000) and local recurrence-free survival (LRFS) (93.6% vs. 84%, p = 0.002).

CONCLUSIONS

The presence of nodal metastases (ypN+) after neoadjuvant therapy containing long-course pelvic irradiation severely impacts the long-term outcome for patients with locally advanced rectal cancer and correlates with multiple clinical and therapeutic variable metrics. Implementation of local and systemic therapies should be adapted and intensified in relation to the finding of ypN+ category in surgical specimens.

Development of a Patient Decision Aid for Rectal Cancer Patients with Clinical Complete Response after Neo-Adjuvant Treatment

Surgery is the primary component of curative treatment for patients with rectal cancer. However, patients with a clinical complete response (cCR) after neo-adjuvant treatment may avoid the morbidity and mortality of radical surgery. An organ-sparing strategy could be an oncological equivalent alternative. Therefore, shared decision making between the patient and the healthcare professional (HCP) should take place. This can be facilitated by a patient decision aid (PtDA). In this study, we developed a PtDA based on a literature review and the key elements of the Ottawa Decision Support Framework. Additionally, a qualitative study was performed to review and evaluate the PtDA by both HCPs and former rectal cancer patients by a Delphi procedure and semi-structured interviews, respectively. A strong consensus was reached after the first round (I-CVI 0.85-1). Eleven patients were interviewed and most of them indicated that using a PtDA in clinical practice would be of added value in the decision making. Patients indicated that their decisional needs are centered on the impact of side effects on their quality of life and the outcome of the different options. The PtDA was modified taking into account the remarks of patients and HCPs and a second Delphi round was held. The second round again showed a strong consensus (I-CVI 0.87-1).

The Correlation Between Survival Benefit of Preoperative Radiotherapy and Pretreatment Carcinoembryonic Antigen Level in Locally Advanced Rectal Cancer

Background

Preoperative radiotherapy followed by radical surgery is the standard treatment for locally advanced rectal cancer; however, its long-term survival benefit remains controversial. This study aimed to determine the relationship between pretreatment carcinoembryonic antigen (CEA) levels and the long-term prognosis of preoperative radiotherapy in locally advanced rectal cancer (LARC) patients.

Methods

Data of LARC patients who underwent surgery between 2011 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database, and patients were accordingly divided into surgery (S) group and radiotherapy followed by surgery (RT+S) group. The primary outcomes were cancer-specific survival (CSS) and cancer-specific mortality (CSM). CSS was evaluated using Kaplan-Meier analysis, while CSM was evaluated using a competitive risk model. Subgroup analysis was also conducted, which was stratified by pretreatment CEA levels.

Results

A total of 2,760 patients were eligible for this study, including 350 (12.7%) patients in the S group and 2,410 (87.3%) in the RT+S group. There were no significant differences in the CSS and CSM rates at 1, 3, and 4 years between the S and RT+S groups before and after PSM (all p > 0.05). Pretreatment CEA levels were independently associated with CSS and CSM after adjusting for age, sex, stage, pathological factors, and treatment factors (all p < 0.05). Subgroup analysis showed that preoperative radiotherapy would benefit patients with elevated CEA in terms of CSS and CSM (both p < 0.05) but not those patients with normal CEA (both p > 0.05). Further analysis showed that preoperative radiotherapy was an independent protective factor for CSS and CSM in patients with elevated CEA levels (both p < 0.05).

Conclusions

Pretreatment CEA level may be considered a potential biomarker to screen LACR patients who would benefit from preoperative radiotherapy in terms of long-term prognosis.

Prevalence of nodal involvement in rectal cancer after chemoradiotherapy

BACKGROUND

The purpose of this study was to investigate the prevalence of ypN+ status according to ypT category in patients with locally advanced rectal cancer treated with chemoradiotherapy and total mesorectal excision, and to assess the impact of ypN+ on disease recurrence and survival by pooled analysis of individual-patient data.

METHODS

Individual-patient data from 10 studies of chemoradiotherapy for rectal cancer were included. Pooled rates of ypN+ disease were calculated with 95 per cent confidence interval for each ypT category. Kaplan-Meier and Cox regression analyses were undertaken to assess influence of ypN status on 5-year disease-free survival (DFS) and overall survival (OS).

RESULTS

Data on 1898 patients were included in the study. Median follow-up was 50 (range 0-219) months. The pooled rate of ypN+ disease was 7 per cent for ypT0, 12 per cent for ypT1, 17 per cent for ypT2, 40 per cent for ypT3, and 46 per cent for ypT4 tumours. Patients with ypN+ disease had lower 5-year DFS and OS (46.2 and 63.4 per cent respectively) than patients with ypN0 tumours (74.5 and 83.2 per cent) (P < 0.001). Cox regression analyses showed ypN+ status to be an independent predictor of recurrence and death.

CONCLUSION

Risk of nodal metastases (ypN+) after chemoradiotherapy increases with advancing ypT category and needs to be considered if an organ-preserving strategy is contemplated.

1.5 T MR-linac planning study to compare two different strategies of rectal boost irradiation

PURPOSE

To compare treatment plans of two different rectal boost strategies: up-front versus adaptive boost at the 1.5 T MR-Linac.

METHODS

Patients with locally advanced rectal cancer (LARC) underwent standard neoadjuvant radiochemotherapy with 50.4 Gy in 28 fractions. T2-weighted MRI prior and after the treatment session were acquired to contour gross tumor volumes (GTVs) and organs at risk (OARs). The datasets were used to simulate four different boost strategies (all with 15 Gy/5 fractions in addition to 50.4 Gy): up-front boost (5 daily fractions in the first week of treatment) and an adaptive boost (one boost fraction per week). Both strategies were planned using standard and reduced PTV margins. Intra-fraction motion was assessed by pre- and post-treatment MRI-based contours.

RESULTS

Five patients were included and a total of 44 MRI sets were evaluated. The median PTV volumes of the adaptive boost were significantly smaller than for the up-front boost (81.4 cm3 vs 44.4 cm3 for PTV with standard margins; 31.2 cm3 vs 15 cm3 for PTV with reduced margins; p = 0.031). With reduced margins the rectum was significantly better spared with an adaptive boost rather than with an up-front boost: V60Gy and V65Gy were 41.2% and 24.8% compared with 59% and 29.9%, respectively (p = 0.031). Median GTV intra-fractional motion was 2 mm (range 0-8 mm).

CONCLUSIONS

The data suggest that the adaptive boost strategy exploiting tumor-shrinkage and reduced margin might result in better sparing of rectum and anal canal. Individual margin assessment, motion management and real-time adaptive radiotherapy appear attractive applications of the 1.5 T MR-Linac for further testing of individualized and safe dose escalation in patients with rectal cancer.

Effect of sequencing of preoperative systemic therapy on patients with locally advanced breast cancer

BACKGROUND

The study aims to perform a clinical trial to evaluate the effect of sequencing of systemic therapy on locally advanced breast cancer (LABC).

METHODS

LABC patients (n = 733) underwent the combination of external beam radiation therapy, chemotherapy, and breast-conservation surgery with difference sequences. Biopsy followed by histopathological examinations was used to assess treatment responses. The primary end point is ipsilateral local recurrence or death. The secondary end points include the incidence and severity of acute and late side effects, cosmesis, and cumulative incidence of regional recurrence and distant metastasis, and survival. The effects of sequence of therapies on the side effects and treatment outcomes were compared.

RESULTS

Patients with preoperative systemic treatment, that is, chemotherapy and radiotherapy performed ahead of surgery, had less fibrosis and pain, and showed higher satisfaction regarding the breast conservation. Preoperative systemic treatment also led to better survival of the patients.

CONCLUSIONS

Preoperative systemic therapy is beneficial to alleviate side effects and improve the breast conservation, treatment outcome, and survival of LABC patients.

Predictive Significance of Mucinous Histology on Pathologic Complete Response Rate Following Capecitabine-Based Neoadjuvant Chemoradiation in Rectal Cancer: a Comparative Study

INTRODUCTION

Currently, neoadjuvant fluoropyrimidine-based chemoradiation followed by surgery is considered the standard of care for locally advanced rectal cancer. The current study aimed to investigate the predictive significance of mucinous histology on the pathologic complete response rate following neoadjuvant chemoradiation in locally advanced rectal cancer and to propose potential new treatment protocol for this specific histology.

MATERIAL AND METHOD

This retrospective study was conducted on 403 patients with locally advanced (clinically T3-4 and/or N1-2) rectal adenocarcinoma who had been treated at three tertiary academic hospitals between 2010 and 2015. Among those 403 patients, 46 (11%) had mucinous rectal cancer (MRC) and 358 (89%) had non-mucinous rectal cancer (NMRC). All patients underwent neoadjuvant chemoradiation with capecitabine followed by low anterior or abdominoperineal resection.

RESULTS

There were 268 men and 135 women with a median age of 55 years (range, 26-82 years). Patients with MRC were younger (p = 0.002) and presented with a larger tumor size (p < 0.001) and a more advanced tumor stage (p = 0.033) compared to the ones with MNRC. In the univariate analysis, female gender (p = 0.009), distal tumor location (p = 0.035), higher tumor stage (p = 0.049), node positivity (p = 0.001), MRC histology (p = 0.017), and high pretreatment CEA level (p = 0.013) were observed to be predictive of a poor pathologic complete response. However, in the multivariate analysis, tumor stage was the single most predictive factor of response to neoadjuvant chemoradiation.

CONCLUSION

Mucinous adenocarcinoma is a significant predictive factor for poor pathologic complete response to neoadjuvant capecitabine-based chemoradiation in patients with locally advanced rectal cancer. New treatment modality based on biomarkers may be considered in future prospective studies because of MRC poor prognosis. Immunotherapy combined with chemotherapy and/or radiotherapy may be an attractive option because of the tumor microsatellite instability-high status.

Dose-time fractionation schedules of preoperative radiotherapy and timing to surgery for rectal cancer

Chemoradiotherapy (CRT) is extensively used prior to surgery for rectal cancer to provide significantly better local control, but the radiotherapy (RT), as the other component of CRT, has been subject to less interest than the drug component in recent years. With considerable developments in RT, the use of advanced techniques, such as intensity-modulated radiotherapy (IMRT) in rectal cancer, is garnering more attention nowadays. The radiation dose can be better conformed to the target volumes with possibilities for synchronous integrated boost without increased complications in normal tissue. Hopefully, both local recurrence and toxicities can be further reduced. Although those seem to be of interest, many issues remain unresolved. There is no international consensus regarding the radiation schedule for preoperative RT for rectal cancer. Moreover, an enormous disparity exists regarding the RT delivery. With the advent of IMRT, variations will likely increase. Moreover, time to surgery is also quite variable, as it depends upon the indication for RT/CRT in the clinical practices. In this review, we discuss the options and problems related to both the dose-time fractionation schedule and time to surgery; furthermore, it addresses the research questions that need answering in the future.

Investigating the association between radiological images and the pathology of rectal cancer treated with neoadjuvant chemotherapy

In patients with rectal cancer treated with neoadjuvant chemotherapy (NAC), differences are often observed between high and low radiological image reduction effects. It may be suggested that high radiological image reduction indicates a beneficial response to chemotherapy. However, the pathological investigation of the differences between high and low radiological cancer volume reduction cases remains limited. In the current study, a total of 50 patients with rectal cancer, treated with NAC, were examined. The approximate pathological primary cancer area and the radiological cancer volume reduction ratio were measured using CT and/or MRI imaging and the donut-shaped measurement method. Immunostaining of cytokeratin AE1/AE3 was performed to quantitatively measure the cancer cell mass in the largest section of rectal cancer. Cytokeratin AE1/AE3-stained area (P=0.04), mitosis (P=0.0027) and radiological donut-shaped images after NAC (P=0.010) were lower in the high radiological cancer volume reduction ratio group compared with the low radiological cancer volume reduction ratio group. These findings indicate that the radiological images had some ability to determine the treatment effect and clinicopathological characteristics of patients with rectal cancer treated with NAC.

Severe Treatment-Related Lymphopenia in Patients with Newly Diagnosed Rectal Cancer

BACKGROUND

Although treatment-related lymphopenia (TRL) is common in many cancers no data exists in rectal cancer.

METHODS

Serial lymphocyte counts were analyzed retrospectively in patients with newly diagnosed rectal cancer, serial blood counts, and complete records at Johns Hopkins Hospital.

RESULTS

Fifty-seven patients with normal pretreatment lymphocyte counts were studied. Two months after beginning chemoradiation, 35% of these patients developed grade III-IV lymphopenia [median lymphocyte counts fell from 1590 to 490 cell/mm³ (p < 0.001)] which persisted throughout one year of observation.

CONCLUSION

Severe and prolonged TRL is common in rectal cancer. Further studies are required to determine TRL's relationship to survival.

Neoadjuvant volumetric modulated arc therapy in rectal cancer and the correlation of pathological response with diffusion-weighted MRI and apoptotic markers

PURPOSE

In this prospective observational study, we aimed to report the applicability and tolerability of neoadjuvant volumetric modulated arc therapy with simultaneous integrated boost (SIB-VMAT) and concurrent chemotherapy in patients with locally advanced rectal cancer (LARC), and to evaluate the correlation of pathological response with apparent diffusion coefficient (ADC) measurements on diffusion-weighted magnetic resonance imaging (DW-MRI) and apoptotic markers.

METHODS

The study enrolled 30 patients with T3 to T4 and/or N+ rectal cancer who preoperatively received SIB-VMAT and concurrent chemotherapy. Before and after the neoadjuvant treatment, apoptotic markers including the nucleosomes and cell-free DNA fragments in the serum samples were examined; DNA integrity was assessed by amplifying the ACTB gene; and the ADC measurements on the DW-MRI were analyzed.

RESULTS

No patients had acute or chronic grade III-IV toxicity. Pathologic complete response (pCR) was achieved in 8 patients (27%), while in 10 patients (33%) near-complete pathological response was obtained. Posttreatment ADC was significantly higher in patients with pCR compared with the others (1.28 vs. 1.10, p = 0.017). ROC curve analysis showed that posttreatment ADC values had a sensitivity of 75% and a specificity of 77.3% for distinguishing the patients with pCR from other responders. On the other hand, posttreatment DNA integrity values were revealed lower than the pretreatment values (p = 0.36). Also, the results revealed an insignificant increase in the posttreatment serum level of nucleosomes (p = 0.72).

CONCLUSIONS

Neoadjuvant SIB-VMAT with concurrent chemotherapy was proved to be a feasible treatment regimen in LARC with tolerable side effects, and improved local control rate and pCR rate.

Preoperative chemoradiotherapy creates an opportunity to perform sphincter preserving resection for low-lying locally advanced rectal cancer based on an oncologic outcome study

Low-lying locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (CRT) can be surgically removed by either abdominperineal resection (APR) or sphincter preserving resection (SPR). This retrospective cohort study of 251 consecutive patients with low lying LARC who underwent CRT followed by radical surgery in a single institute, between March 2003 and November 2012, aimed to compare the oncological benefits between the two groups. 3-year disease free survival (DFS), overall survival (OS), cumulative incidence of recurrence and postoperative complications were compared between the two approaches. With median follow-up of 48.6 months, SPR group had higher 3-year DFS rate (86.4% vs 73.6%, P=0.023) and lower incidence of distant recurrence (12.0% vs 23.7%, P=0.026). The postoperative complications, incidence of local recurrence and the 3-year OS were comparable between the two groups. Pathologic T and N stage were the independent predictors for 3-year DFS (P=0.020 and P<0.001). In conclusion, our study suggest that low-lying LARC patients with a significant response to preoperative CRT can benefit from the advantage of SPR in preserving the anal sphincter function without compromising their oncologic outcome.

The efficacy of adding targeted agents to neoadjuvant therapy for locally advanced rectal cancer patients: a meta-analysis

Patients with locally advanced rectal cancer (LARC) are at tremendous risk of metastatic diseases. To improve the prognoses of LARC patients, the efficacy of adding targeted agents to neoadjuvant therapy has been investigated by many researchers but remains controversial. A literature search of relevant databases was conducted through December 2016, 804 studies were identified and 32 investigations were ultimately included. A total of 1196 patients from 31 cohorts of 29 studies were eligible for quantitative synthesis in this single‐arm setting meta‐analysis. As pathologic complete response (pCR) shows promise as a prognosis indicator, we focused on pCR rates to evaluate whether adding targeted agents to neoadjuvant therapies improves the outcome of LARC patients. In our study, we revealed pooled estimates of pCR of 27% (95%CI, 21–34%) and 14% (95%CI, 9–21%) for bevacizumab‐relevant cohorts and cetuximab‐relevant cohorts, respectively. The safety of adding targeted agents to neoadjuvant therapy was also evaluated by pooling the data of Grade 3/4 toxicity. In conclusion, our study revealed that adding bevacizumab to the neoadjuvant therapy regimens provides appreciable pCR for LARC patients. Meanwhile, the efficacy of cetuximab remains inconclusive, RCTs with larger scale and better study design that stress more on mutational status are needed.

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.

Importance of the Circumferential Extent of Tumors and Clinical Lymph Node Status as Prognostic Factors after Preoperative Chemoradiotherapy and Surgery in Patients with Rectal Cancer

Aims and background

To evaluate the clinical factors that influence pathological and clinical outcomes after preoperative concurrent chemoradiotherapy in patients with rectal cancer.

Methods

Between 1999 and 2004, 121 patients with cT3-4 or node-positive rectal cancer received preoperative chemoradiotherapy and surgery. Preoperative radiation therapy with 45 Gy was delivered. Fluorouracil-based chemotherapy was administered to most of the patients.

Results

Pathological complete remission was 14.3% after preoperative chemoradiotherapy. More than 60% tumor circumferential extent was an independent adverse factor for complete remission (P = 0.011, HR 4.643, 95% CI 1.415–15.231). Local recurrence developed in 9.9% of the cases. Serum CEA level ≥5 ng/ml (P = 0.057, HR 3.022, 95% CI 0.967–9.441) and >60% circumferential extent of tumor (P = 0.064, HR 4.232, 95% CI 0.918–19.531) were marginal adverse factors for local recurrence. Five-year disease-free survival and overall survival were 72.2% and 86.6%, respectively. Disease-free survival was poor for patients with the lymph nodes ≥1 cm in diameter (P = 0.028), cN2 stage disease (P = 0.047) and >60% circumferential extent of tumor (P = 0.058). Multivariate analysis for disease-free survival showed that the lymph node size ≥1 cm was an adverse factor (P = 0.019, HR 2.380, 95% CI 1.115–4.906). Patients with >60% circumferential extent of tumor and cN2 stage had a more unfavorable survival than the other patients (disease-free survival, P = 0.018; overall survival, P = 0.015). Patients with >60% circumferential extent of tumor and/or lymph node ≥1 cm also had an unfavorable survival (disease-free survival, P = 0.016; overall survival, P = 0.049).

Conclusions

In rectal cancer, circumferential extent of tumor and clinical lymph node status were important factors for preoperative chemoradiotherapy and surgery. A further prospective study is needed to confirm and expand these findings.

The Impact of Novel Radiation Treatment Techniques on Toxicity and Clinical Outcomes In Rectal Cancer

Purpose of review

Three-dimensional conformal radiation therapy (3DCRT) has been the standard technique in the treatment of rectal cancer. The use of new radiation treatment technologies such as intensity-modulated radiation therapy (IMRT), proton therapy (PT), stereotactic body radiation therapy (SBRT) and brachytherapy (BT) has been increasing over the past 10 years. This review will highlight the advantages and drawbacks of these techniques.

Recent findings

IMRT, PT, SBRT and BT achieve a higher target coverage conformity, a higher organ at risk sparing and enable dose escalation compared to 3DCRT. Some studies suggested a reduction in gastrointestinal and hematologic toxicities and an increase in the complete pathologic response rate; however, the clinical benefit of these techniques remains controversial.

Summary

The results of these new techniques seem encouraging despite conclusive data. Further trials are required to establish their role in rectal cancer.

Results of intraoperative electron beam radiotherapy containing multimodality treatment for locally unresectable T4 rectal cancer: a pooled analysis of the Mayo Clinic Rochester and Catharina Hospital Eindhoven

BACKGROUND

The aim of this study is to analyse the pooled results of intraoperative electron beam radiotherapy (IOERT) containing multimodality treatment of locally advanced T4 rectal cancer, initially unresectable for cure, from the Mayo Clinic, Rochester, USA (MCR) and Catharina Hospital, Eindhoven, The Netherlands (CHE), both major referral centers for locally advanced rectal cancer. A rectal tumor is called locally unresectable for cure if after full clinical work-up infiltration into the surrounding structures or organs has been demonstrated, which would result in positive surgical margins if resection was the initial component of treatment. This was the reason to refer these patients to the IOERT program of one of the centers.

METHODS

In the period from 1981 to 2010, 417 patients with locally unresectable T4 rectal carcinomas at initial presentation were treated with multimodality treatment including IOERT at either one of the two centres. The preferred treatment approach was preoperative (chemo) radiation and intended radical surgery combined with IOERT. Risk factors for local recurrence (LR), cancer specific survival, disease free survival and distant metastases (DM) were assessed.

RESULTS

A total of 306 patients (73%) underwent a R0 resection. LRs and metastases occurred more frequently after an R1-2 resection (P<0.001 and P<0.001 respectively). Preoperative chemoradiation (preop CRT) was associated with a higher probability of having a R0 resection. Waiting time after preoperative treatment was inversely related with the chance of developing a LR, especially after R+ resection. In 16% of all cases a LR developed. Five-year disease free survival and overall survival (OS) were 55% and 56% respectively.

CONCLUSIONS

An acceptable survival can be achieved in treatment of patients with initially unresectable T4 rectal cancer with combined modality therapy that includes preop CRT and IOERT. Completeness of the resection is the most important predictive and prognostic factor in the treatment of T4 rectal cancer for all outcome parameters. IOERT can reduce the LR rate effectively, especially in R+ resected patients.

Severe weight loss during preoperative chemoradiotherapy compromises survival outcome for patients with locally advanced rectal cancer

Purpose

In addition to tumor factors, poor nutritional status before and during anti-tumor treatment might compromise prognosis in several types of cancer. This study was done to determine the impact of weight loss during preoperative chemoradiotherapy (CRT) on the survival outcome of patients with locally advanced rectal cancer (LARC).

Methods

The retrospective study examined consecutive patients with LARC who underwent preoperative CRT followed by radical resection in a single institute, between 2003 and 2013. Correlation of proportional body mass index (BMI) change after preoperative CRT and patient’s demographics, tumor characteristics, treatment parameters, CRT-related toxicity, disease-free survival (DFS) and overall survival (OS) were investigated.

Results

A total of 364 patients were enrolled, and BMI loss was found in 243 patients (66.2 %) after preoperative CRT. Severe weight loss (SWL) was defined as BMI loss ≥7 %. Thirty-nine (10.7 %) cases were enrolled in SWL cohort and found to have higher incidence of diarrhea (P = 0.033), renal disorder (P = 0.033) and grade 3–4 radiation proctitis (P = 0.041). Although no significant difference was found in 3-year DFS, patients in SWL cohort showed significantly worse 3-year OS rate (71.8 vs 88.0 %, P = 0.030) than the others. In univariate analysis, BMI loss ≥7 %, completed dose of preoperative chemotherapy, pathologic T and N stages were correlated with OS (all P < 0.05). In multivariable analysis, BMI loss ≥7 % (HR 1.984; 95 % CI 1.061–3.709; P = 0.032) remained the independent prognostic factor for OS.

Conclusions

Our results demonstrate that SWL during preoperative CRT indeed compromises survival outcome in patients with LARC. Routine nutritional monitoring and nutritional support during preoperative CRT are suggested as the integral part of the multidisciplinary approach for these patients.

Watch and Wait?--Elevated Pretreatment CEA Is Associated with Decreased Pathological Complete Response in Rectal Cancer

INTRODUCTION

Between 10 and 30% of rectal cancer patients experience pathological complete response after neoadjuvant treatment. However, physiological factors predicting which patients will experience tumor response are largely unknown. Previous single-institution studies have suggested an association between elevated pretreatment carcinoembryonic antigen and decreased pathological complete response.

METHODS

Clinical stage II-III rectal cancer patients undergoing neoadjuvant chemoradiotherapy and surgical resection were selected from the 2006-2011 National Cancer Data Base. Multivariable analysis was used to examine the association between elevated pretreatment carcinoembryonic antigen and pathological complete response, pathological tumor regression, tumor downstaging, and overall survival.

RESULTS

Of the 18,113 patients meeting the inclusion criteria, 47% had elevated pretreatment carcinoembryonic antigen and 13% experienced pathological compete response. Elevated pretreatment carcinoembryonic antigen was independently associated with decreased pathological complete response (OR = 0.65, 95% CI = 0.52-0.77, p < 0.001), pathological tumor regression (OR = 0.74, 95% CI = 0.67-0.70, p < 0.001), tumor downstaging (OR = 0.77, 95% CI = 0.63-0.92, p < 0.001), and overall survival (HR = 1.45, 95% CI = 1.34-1.58, p < 0.001).

CONCLUSION

Rectal cancer patients with elevated pretreatment carcinoembryonic antigen are less likely to experience pathological complete response, pathological tumor regression, and tumor downstaging after neoadjuvant treatment and experience decreased survival. These patients may not be suitable candidates for an observational "watch-and-wait" strategy. Future prospective studies should investigate the relationships between CEA levels, neoadjuvant treatment response, recurrence, and survival.

Extended Intervals after Neoadjuvant Therapy in Locally Advanced Rectal Cancer: The Key to Improved Tumor Response and Potential Organ Preservation

BACKGROUND

Many rectal cancer patients experience tumor downstaging and some are found to achieve a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT). Previous data suggest that there is an association between the time interval from nCRT completion to surgery and tumor response rates, including pCR. However, these studies have been primarily from single institutions with small sample sizes. The aim of this study was to examine the relationship between a longer interval after nCRT and pCR in a nationally representative cohort of rectal cancer patients.

STUDY DESIGN

Clinical stage II to III rectal cancer patients undergoing nCRT with a documented surgical resection were selected from the 2006 to 2011 National Cancer Data Base. Multivariable logistic regression analysis was used to assess the association between the nCRT-surgery interval time (<6 weeks, 6 to 8 weeks, >8 weeks) and the odds of pCR. The relationship between nCRT-surgery interval, surgical morbidity, and tumor downstaging was also examined.

RESULTS

Overall, 17,255 patients met the inclusion criteria. An nCRT-surgery interval time >8 weeks was associated with higher odds of pCR (odds ratio [OR] 1.12, 95% CI 1.01 to 1.25) and tumor downstaging (OR 1.11, 95% CI 1.02 to 1.25). The longer time delay was also associated with lower odds of 30-day readmission (OR 0.82, 95% CI 0.70 to 0.92).

CONCLUSIONS

An nCRT-surgery interval time >8 weeks results in increased odds of pCR, with no evidence of associated increased surgical complications compared with an interval of 6 to 8 weeks. These data support implementation of a lengthened interval after nCRT to optimize the chances of pCR and perhaps add to the possibility of ultimate organ preservation (nonoperative management).

Integrated Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) and Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) Quantitative Proteomic Analysis Identifies Galectin-1 as a Potential Biomarker for Predicting Sorafenib Resistance in Liver Cancer

Sorafenib has become the standard therapy for patients with advanced hepatocellular carcinoma (HCC). Unfortunately, most patients eventually develop acquired resistance. Therefore, it is important to identify potential biomarkers that could predict the efficacy of sorafenib. To identify target proteins associated with the development of sorafenib resistance, we applied stable isotope labelling with amino acids in cell culture (SILAC)-based quantitative proteomic approach to analyze differences in protein expression levels between parental HuH-7 and sorafenib-acquired resistance HuH-7 (HuH-7(R)) cells in vitro, combined with an isobaric tags for relative and absolute quantitation (iTRAQ) quantitative analysis of HuH-7 and HuH-7(R) tumors in vivo. In total, 2,450 quantified proteins were identified in common in SILAC and iTRAQ experiments, with 81 showing increased expression (>2.0-fold) with sorafenib resistance and 75 showing decreased expression (<0.5-fold). In silico analyses of these differentially expressed proteins predicted that 10 proteins were related to cancer with involvements in cell adhesion, migration, and invasion. Knockdown of one of these candidate proteins, galectin-1, decreased cell proliferation and metastasis in HuH-7(R) cells and restored sensitivity to sorafenib. We verified galectin-1 as a predictive marker of sorafenib resistance and a downstream target of the AKT/mTOR/HIF-1α signaling pathway. In addition, increased galectin-1 expression in HCC patients' serum was associated with poor tumor control and low response rate. We also found that a high serum galectin-1 level was an independent factor associated with poor progression-free survival and overall survival. In conclusion, these results suggest that galectin-1 is a possible biomarker for predicting the response of HCC patients to treatment with sorafenib. As such, it may assist in the stratification of HCC and help direct personalized therapy.

Phase space determination from measured dose data for intraoperative electron radiation therapy

A procedure to characterize beams of a medical linear accelerator for their use in Monte Carlo (MC) dose calculations for intraoperative electron radiation therapy (IOERT) is presented. The procedure relies on dose measurements in homogeneous media as input, avoiding the need for detailed simulations of the accelerator head. An iterative algorithm (EM-ML) has been employed to extract the relevant details of the phase space (PHSP) of the particles coming from the accelerator, such as energy spectra, spatial distribution and angle of emission of particles. The algorithm can use pre-computed dose volumes in water and/or air, so that the machine-specific tuning with actual data can be performed in a few minutes. To test the procedure, MC simulations of a linear accelerator with typical IOERT applicators and energies, have been performed and taken as reference. A solution PHSP derived from the dose produced by the simulated accelerator has been compared to the reference PHSP. Further, dose delivered by the simulated accelerator for setups not included in the fit of the PHSP were compared to the ones derived from the solution PHSP. The results show that it is possible to derive from dose measurements PHSP accurate for IOERT MC dose estimations.

Adjuvant chemotherapy in rectal cancer: defining subgroups who may benefit after neoadjuvant chemoradiation and resection: a pooled analysis of 3,313 patients

Recent literature suggests that the benefit of adjuvant chemotherapy (aCT) for rectal cancer patients might depend on the response to neoadjuvant chemoradiation (CRT). Aim was to evaluate whether the effect of aCT in rectal cancer is modified by response to CRT and to identify which patients benefit from aCT after CRT, by means of a pooled analysis of individual patient data from 13 datasets. Patients were categorized into three groups: pCR (ypT0N0), ypT1-2 tumour and ypT3-4 tumour. Hazard ratios (HR) for the effect of aCT were derived from multivariable Cox regression analyses. Primary outcome measure was recurrence-free survival (RFS). One thousand seven hundred and twenty three (1723) (52%) of 3,313 included patients received aCT. Eight hundred and ninety eight (898) patients had a pCR, 966 had a ypT1-2 tumour and 1,302 had a ypT3-4 tumour. For 122 patients response, category was missing and 25 patients had ypT0N+. Median follow-up for all patients was 51 (0-219) months. HR for RFS with 95% CI for patients treated with aCT were 1.25(0.68-2.29), 0.58(0.37-0.89) and 0.83(0.66-1.10) for patients with pCR, ypT1-2 and ypT3-4 tumours, respectively. The effect of aCT in rectal cancer patients treated with CRT differs between subgroups. Patients with a pCR after CRT may not benefit from aCT, whereas patients with residual tumour had superior outcomes when aCT was administered. The test for interaction did not reach statistical significance, but the results support further investigation of a more individualized approach to administer aCT after CRT and surgery based on pathologic staging.

Influence of intraoperative radiotherapy (IORT) on perioperative outcome after surgical resection of rectal cancer

BACKGROUND

Intraoperative radiotherapy (IORT) for locally advanced or recurrent rectal cancer as an integral part of multimodal treatment might be an option to reduce local cancer recurrence. The aim of the present study was to determine the influence of IORT on the postoperative outcome and complications rates in the treatment of patients with adenocarcinoma of the rectum in comparison to patients with rectum resection only.

METHODS

A total of 162 patients underwent operation for International Union against Cancer stage III/IV rectal cancer or recurrent rectal cancer at our surgical department between 2004 and 2012. They were divided into two groups depending on whether they received IORT or not. General patient details, tumor, and operation details, as well as perioperative major and minor complications, were registered and compared.

RESULTS

Of the 162 patients treated for stage III/IV rectal cancer, 52 underwent rectal resection followed by IORT. Complication rates were similar in the two groups. Operative time was significantly longer in the IORT group (248 ± 84 vs 177 ± 68 min; p < 0.001). No significant differences were found concerning anastomotic leakage rate, hospital stay, or wound infection rate.

CONCLUSIONS

Intraoperative radiotherapy appears to be a safe treatment option in patients with locally advanced or recurrent rectal cancer with acceptable complication rates. The effect on local recurrence rate has to be estimated in long-term follow-up.

Intraoperative radiotherapy for locally advanced or locally recurrent rectal cancer: Does it work at all?

BACKGROUND

Intraoperative radiotherapy (IORT) has been given for primary and locally recurrent rectal cancer for 30 years. Still, its effect is not clear.

MATERIAL AND METHODS

PubMed and EMBASE search for papers after 1989 on surgical treatment and external beam radiotherapy (EBRT) for primary advanced and locally recurrent rectal cancer, with and without IORT. From each center the most recent paper was generally selected. Survival and local recurrence at five years was tabulated for the total groups and separate R-stages. Also, the technique for IORT, use of EBRT and chemotherapy as well as surgical approach was registered.

RESULTS

In primary cancer 18 papers from 14 centers were tabulated, including one randomized and five internally comparing studies, as well as seven studies without IORT. In locally recurrent cancer 18 papers from 13 centers were tabulated, including four internally comparing studies and also five without IORT. Overall survival (OS) and local recurrence rate (LRR) were higher for primary cancer compared to recurrent cancer. Patients with R0 resections had better outcome than patients with R1 or R2 resections. For primary cancer OS and LR rate of the total groups and R0 stages was not influenced by IORT. An effect on R1/R2 stages cannot be excluded. The only randomized study (primary cancer) did not show any effect of IORT.

CONCLUSION

IORT does not convincingly improve OS and LR rate for primary and locally recurrent rectal cancer. If there is an effect of IORT, it is small and cannot be shown outside randomized studies analyzing the separate R stages.

Intraoperative radiotherapy with electrons: fundamentals, results, and innovation

Rationale and objectives

To analyse the programme activity and clinical innovation and/or technology developed over a period of 17 years with regard to the introduction and the use of intraoperative radiotherapy (IORT) as a therapeutic component in a medical–surgical multidisciplinary cancer hospital.

Material and methods

To standardise and record this procedure, the Radiation Oncology service has an institutional programme and protocols that must be completed by the different specialists involved. For 17 years, IORT procedures were recorded on a specific database that includes 23 variables with information recorded on institutional protocols.

As part of the development and innovation activity, two technological tools were implemented (RADIANCE and MEDTING) in line with the standardisation of this modality in clinical practice.

Results

During the 17 years studied, 1,004 patients were treated through 1,036 IORT procedures. The state of the disease at the time of IORT was 77% primary and 23% recurrent. The origin and distribution of cancers were 62% gastrointestinal, 18% sarcomas, 5% pancreatic, 2% paediatric, 3% breast, 7% less common locations, and 2% others. The research and development projects have generated a patent on virtual planning (RADIANCE) and proof of concept to explore as a professional social network (MEDTING).

During 2012, there were 69 IORT procedures. There was defined treatment volume (target or target region) in all of them, and 43 were conducted by the virtual planning RADIANCE system. Eighteen have been registered on the platform MEDTING as clinical cases.

Conclusion

The IORT programme, developed in a university hospital with an academic tradition, and interdisciplinary surgical oncology, is a feasible care initiative, able to generate the necessary intense clinical activity for tending to the cancer patient. Moreover, it is a competitive source for research, development, and scientific innovation.

Intraoperative radiotherapy in colorectal cancer: systematic review and meta-analysis of techniques, long-term outcomes, and complications

BACKGROUND

The precise contribution of IORT to the management of locally advanced and recurrent colorectal cancer (CRC) remains uncertain. We performed a systematic review and meta-analysis to assess the value of IORT in this setting.

METHODS

Studies published between 1965 and 2011 that reported outcomes after IORT for advanced or recurrent CRC were identified by an electronic literature search. Studies were assessed for methodological quality and design, and evaluated for technique of IORT delivery, oncological outcomes, and complications following IORT. Outcomes were analysed with fixed-effect and random-effect model meta-analyses and heterogeneity and publication bias examined.

RESULTS

29 studies comprising 14 prospective and 15 retrospective studies met the inclusion criteria and were assessed, yielding a total of 3003 patients. The indication for IORT was locally advanced disease in 1792 patients and locally recurrent disease in 1211 patients. Despite heterogeneity in methodology and reporting practice, IORT is principally applied for the treatment of close or positive margins. When comparative studies were evaluated, a significant effect favouring improved local control (OR 0.22; 95% CI = 0.05-0.86; p = 0.03), disease free survival (HR 0.51; 95% CI = 0.31-0.85; p = 0.009), and overall survival (HR 0.33; 95% CI = 0.2-0.54; p = 0.001) was noted with no increase in total (OR 1.13; 95% CI = 0.77-1.65; p = 0.57), urologic (OR 1.35; 95% CI = 0.84-2.82; p = 0.47), or anastomotic complications (OR 0.94; 95% CI = 0.42-2.1; p = 0.98). Increased wound complications were noted after IORT (OR 1.86; 95% CI = 1.03-3.38; p = 0.049).

CONCLUSIONS

Despite methodological weaknesses in the studies evaluated, our results suggest that IORT may improve oncological outcomes in advanced and recurrent CRC.

Laparoscopic abdominoperineal resection with intraoperative radiotherapy for locally advanced low rectal cancer

AIMS

Intraoperative radiotherapy (IORT) for locally advanced rectal cancer as an integral part of multimodal treatment, may lead to reduced local recurrence but it is not routinely used. The aim of this paper is to describe our experience with IORT in the treatment of patients with locally advanced adenocarcinoma of the lower third of the rectum.

MATERIAL AND METHODS

Laparoscopic abdominoperineal amputation of the rectum with intraoperative radiotherapy was performed on 17 patients, 13 men and 4 women, median age 64 years (49-75 years) between 2010-2011. All patients underwent complete therapy according to the treatment protocol.

RESULTS

In one patient, the laparoscopic procedure had to be converted to an open resection. The duration of the surgical procedure with IORT was 185 to 345 min (median 285 min). In 14 cases, the intraoperative dose was 10 Gy and in two patients a dose of 12 Gy was used. There were no severe intraoperative complications. Blood loss ranged from 30 to 500 mL (median 100 mL). There were postoperative complications in 4 patients (23.5%); 2 necessitated surgical reintervention (11.8%). The duration of postoperative hospitalization was 6 to 35 days (median 7 days). In the follow-up of 2 to 16 months (median 12 months), no local recurrence or disease generalization have been found to date.

CONCLUSIONS

The results show the technical feasibility of laparoscopically assisted abdominoperineal amputation of the rectum in combination with IORT in the treatment of locally advanced rectal carcinoma with an acceptable risk of postperative complications.

Intraoperative radiation therapy with the photon radiosurgery system in locally advanced and recurrent rectal cancer: retrospective review of the Cleveland clinic experience

Background

Patients with locally advanced or recurrent rectal cancer often require multimodality treatment. Intraoperative radiation therapy (IORT) is a focal approach which aims to improve local control.

Methods

We retrospectively reviewed 42 patients treated with IORT following definitive resection of a locally advanced or recurrent rectal cancer from 2000–2009. All patients were treated with the Intrabeam® Photon Radiosurgery System (PRS). A dose of 5 Gy was prescribed to a depth of 1 cm (surface dose range: 13.4-23.1, median: 14.4 Gy). Median survival times were calculated using Kaplan-Meier analysis.

Results

Of 42 patients, 32 had recurrent disease (76%) while 10 had locally advanced disease (24%). Eighteen patients (43%) had tumors fixed to the sidewall. Margins were positive in 19 patients (45%). Median follow-up after IORT was 22 months (range 0.2-101). Median survival time after IORT was 34 months. The 3-year overall survival rate was 49% (43% for recurrent and 65% for locally advanced patients). Local recurrence was evaluable in 34 patients, of whom 32% failed. The 1-year local recurrence rate was 16%. Distant metastasis was evaluable in 30 patients, of whom 60% failed. The 1-year distant metastasis rate was 32%. No intraoperative complications were attributed to IORT. Median duration of IORT was 35 minutes (range: 14–39). Median discharge time after surgery was 7 days (range: 2–59). Hydronephrosis after IORT occurred in 10 patients (24%), 7 of whom had documented concomitant disease recurrence.

Conclusions

The Intrabeam® PRS appears to be a safe technique for delivering IORT in rectal cancer patients. IORT with PRS marginally increased operative time, and did not appear to prolong hospitalization. Our rates of long-term toxicity, local recurrence, and survival rates compare favorably with published reports of IORT delivery with other methods.

Toward the non-surgical management of locally advanced rectal cancer

Neoadjuvant short-course radiotherapy and long-course chemoradiation (CRT) reduce local recurrence rates when compared to surgery alone and remain widely accepted as standard of care for patients with locally advanced rectal cancer. However, surgery is not without complications and a non-surgical approach in carefully selected patients warrants evaluation. A pathological complete response to CRT is associated with a significant improvement in survival and it has been suggested that a longer time interval between the completion of CRT and surgery increases tumor downstaging. Intensification of neoadjuvant treatment regimens to increase tumor downstaging has been evaluated in a number of clinical trials and more recently the introduction of neoadjuvant chemotherapy prior to CRT has demonstrated high rates of radiological tumor regression. Careful selection of patients using high-resolution MRI may allow a non-surgical approach in a subgroup of patients achieving a complete response to neoadjuvant therapies after an adequate time period. Clearly this needs prospective evaluation within a clinical trial setting, incorporating modern imaging techniques, and tissue biomarkers to allow accurate prediction and assessment of response.

An innovative tool for intraoperative electron beam radiotherapy simulation and planning: description and initial evaluation by radiation oncologists

PURPOSE

Intraoperative electron beam radiation therapy (IOERT) involves a modified strategy of conventional radiation therapy and surgery. The lack of specific planning tools limits the spread of this technique. The purpose of the present study is to describe a new simulation and planning tool and its initial evaluation by clinical users.

METHODS AND MATERIALS

The tool works on a preoperative computed tomography scan. A physician contours regions to be treated and protected and simulates applicator positioning, calculating isodoses and the corresponding dose--volume histograms depending on the selected electron energy. Three radiation oncologists evaluated data from 15 IOERT patients, including different tumor locations. Segmentation masks, applicator positions, and treatment parameters were compared.

RESULTS

High parameter agreement was found in the following cases: three breast and three rectal cancer, retroperitoneal sarcoma, and rectal and ovary monotopic recurrences. All radiation oncologists performed similar segmentations of tumors and high-risk areas. The average applicator position difference was 1.2 ± 0.95 cm. The remaining cancer sites showed higher deviations because of differences in the criteria for segmenting high-risk areas (one rectal, one pancreas) and different surgical access simulated (two rectal, one Ewing sarcoma).

CONCLUSIONS

The results show that this new tool can be used to simulate IOERT cases involving different anatomic locations, and that preplanning has to be carried out with specialized surgical input.

Four-week neoadjuvant intensity-modulated radiation therapy with concurrent capecitabine and oxaliplatin in locally advanced rectal cancer patients: a validation phase II trial

PURPOSE

To validate tolerance and pathological complete response rate (pCR) of a 4-week preoperative course of intensity-modulated radiation therapy (IMRT) with concurrent capecitabine and oxaliplatin (CAPOX) in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

Patients with T3 to T4 and/or N+ rectal cancer received preoperative IMRT (47.5 Gy in 19 fractions) with concurrent capecitabine (825 mg/m(2) b.i.d., Monday to Friday) and oxaliplatin (60 mg/m(2) on Days 1, 8, and 15). Surgery was scheduled 4 to 6 weeks after the completion of chemoradiation. Primary end points were toxicity and pathological response rate. Local control (LC), disease-free survival (DFS), and overall survival (OS) were also analyzed.

RESULTS

A total of 100 patients were evaluated. Grade 1 to 2 proctitis was observed in 73 patients (73%). Grade 3 diarrhea occurred in 9% of the patients. Grade 3 proctitis in 18% of the first 50 patients led to reduction of the dose per fraction to 47.5 Gy in 20 treatments. The rate of Grade 3 proctitis decreased to 4% thereafter (odds ratio, 0.27). A total of 99 patients underwent surgery. A pCR was observed in 13% of the patients, major response (96-100% of histological response) in 48%, and pN downstaging in 78%. An R0 resection was performed in 97% of the patients. After a median follow-up of 55 months, the LC, DFS, and OS rates were 100%, 84%, and 87%, respectively.

CONCLUSIONS

Preoperative CAPOX-IMRT therapy (47.5 Gy in 20 fractions) is feasible and safe, and produces major pathological responses in approximately 50% of patients.

Surgical Complications and Pathologic Complete Response after Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer

Pathologic complete response (pCR) to neoadjuvant chemoradiation (CRT) in patients with rectal cancer is associated with improved prognosis, whereas postoperative surgical complications have been linked with poor oncologic outcomes. Our objective was to examine the association between postoperative complications and pCR. We analyzed 127 patients enrolled in a prospective multicenter study investigating rectal cancer response to CRT. Surgical complications were scored according to the Clavien-Dindo scale (Grade 1 to 4). Among the 127 patients analyzed, 28 (22%) patients had a pCR. In the pCR group, six surgical Grade 3+ complications occurred in five (18%) patients, including anastomotic leak (n = 2), ureteral injury (n = 2), pelvic abscess (n = 1), and pneumonia (n = 1). In the non-pCR group, there were 10 Grade 3+ complications in eight (8%) patients, including severe obstruction (n = 1), postoperative hemorrhage (n = 1), leak (n = 2), pelvic abscess (n = 2), ureteral injury (n = 1), and severe morbidity (stroke, n = 1; acute respiratory distress, n = 1; and cardiac event, n = 1). There was no significant difference in the frequency of total surgical complications between pCR and non-pCR patients; and no association was observed between pCR and major postoperative complications. In conclusion, postoperative complication rates do not differ between pCR and non-pCR groups. The occurrence of major postoperative complications is not associated with response to neoadjuvant CRT.

Identification of a biomarker profile associated with resistance to neoadjuvant chemoradiation therapy in rectal cancer

OBJECTIVE

To identify a biomarker profile associated with tumor response to chemoradiation (CRT) in locally advanced rectal cancer.

BACKGROUND

Rectal cancer response to neoadjuvant CRT is variable. Whereas some patients have a minimal response, others achieve a pathologic complete response (pCR) and have no viable cancer cells in their surgical specimens. Identifying biomarkers of response will help select patients more likely to benefit from CRT.

METHODS

This study includes 132 patients with locally advanced rectal cancer treated with neoadjuvant CRT followed by surgery. Tumor DNA from pretreatment tumor biopsies and control DNA from paired normal surgical specimens was screened for mutations and polymorphisms in 23 genes. Genetic biomarkers were correlated with tumor response to CRT (pCR vs non-pCR), and the association of single or combined biomarkers with tumor response was determined.

RESULTS

Thirty-three of 132 (25%) patients achieved a pCR and 99 (75%) patients had non-pCR. Three individual markers were associated with non-pCR; v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutation (P = 0.0145), cyclin D1 G870A (AA) polymorphism (P = 0.0138), and methylenetetrahydrofolate reductase (NAD(P)H) C677T (TT) polymorphism (P = 0.0120). Analysis of biomarker combinations revealed that none of the 27 patients with both tumor protein p53 (p53) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations had a pCR. Further, in patients with both p53 and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations or the cyclin D1 G870A (AA) polymorphism or the methylenetetrahydrofolate reductase (NAD(P)H) C677T (TT) polymorphism (n = 52) the association with non-pCR was further strengthened; 51 of 52 (98%) of patients were non-pCR. These biomarker combinations had a validity of more than 70% and a positive predictive value of 97% to 100%, predicting that patients harboring these mutation/polymorphism profiles will not achieve a pCR.

CONCLUSIONS

A specific biomarker profile is strongly associated with non-pCR to CRT and could be used to select optimal oncologic therapy in rectal cancer patients. ClinicalTrials.org Identifier: NCT00335816.

Molecular diagnosis of response to neoadjuvant chemoradiation therapy in patients with locally advanced rectal cancer

BACKGROUND

Pathologic complete response (pCR) to neoadjuvant chemoradiation (CRT) is an important prognostic factor in locally advanced rectal cancer. However, it is uncertain if histopathological techniques accurately detect pCR. We tested a novel molecular approach for detecting pCR and compared it with current histopathological approaches.

STUDY DESIGN

Pretreatment tumor biopsies and surgical specimens were collected from 96 patients with locally advanced rectal cancer treated with neoadjuvant CRT and surgery. Tumor response was categorized by tumor regression grade. Tumor DNA from pre-CRT tumor biopsies was screened for K-ras and p53 mutations. DNA from paired surgical specimens was then screened for the same mutations using highly sensitive polymerase chain reaction-based techniques.

RESULTS

Sixty-eight of 96 (71%) pretreatment biopsies harbored K-ras and/or p53 mutation; 36 (38%) had K-ras mutations, 52 (54%) had p53 mutations, and 20 (21%) carried both mutations. Of 70 patients with tumor regression grades 1 to 3, sixty-six (94%) had a concordant K-ras and p53 mutation profile in pre- and post-treatment tissues. Of 26 patients with tumor regression grade 0 (pCR), 12 had K-ras or p53 mutations in pretreatment biopsies. Of these, 2 (17%) patients had the same K-ras (n = 1) or p53 (n = 1) mutation detected in post-treatment tissue.

CONCLUSIONS

Sensitive molecular techniques detect K-ras and p53 mutations in post-CRT surgical specimens in some patients with a pCR. This suggests histopathological techniques might not be completely accurate, and some patients diagnosed with a pCR to CRT might have occult cancers cells in their surgical specimens.

Efficacy and safety of intraoperative radiotherapy in colorectal cancer: a systematic review

Intraoperative radiotherapy (IORT) has been proposed as an encouraging treatment for colorectal cancer. The aim of this study is to assess the efficacy and safety of IORT for this cancer through a systematic review. Studies located in electronic databases were selected according to established criteria, read and analysed and the results extracted by two independent reviewers. Fifteen studies met the selection criteria. Five-to-six-year local control (LC) was over 80% and 5-year overall survival (OS) was close to 65%. For recurrences, the 5-year overall survival was 30%. The main acute complications were gastrointestinal. Adding IORT to conventional treatment reduces the incidence of local recurrences within the radiation area over 10%. IORT is a safe technique as it does not increase toxicity associated with conventional treatment.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

Patterns of response after preoperative treatment in gastric cancer

PURPOSE

To analyze the rate of pathologic response in patients with locally advanced gastric cancer treated with preoperative chemotherapy with and without chemoradiation at our institution.

METHODS AND MATERIALS

From 2000 to 2007 patients were retrospectively identified who received preoperative treatment for gastric cancer (cT3-4/ N+) with induction chemotherapy (Ch) or with Ch followed by concurrent chemoradiotherapy (45 Gy in 5 weeks) (ChRT). Surgery was planned 4-6 weeks after the completion of neoadjuvant treatment. Pathologic assessment was used to investigate the patterns of pathologic response after neoadjuvant treatment.

RESULTS

Sixty-one patients were analyzed. Of 61 patients, 58 (95%) underwent surgery. The R0 resection rate was 87%. Pathologic complete response was achieved in 12% of the patients. A major pathologic response (<10% of residual tumor) was observed in 53% of patients, and T downstaging was observed in 75%. Median follow-up was 38.7 months. Median disease-free survival (DFS) was 36.5 months. The only patient-, tumor-, and treatment-related factor associated with pathologic response was the use of preoperative ChRT. Patients achieving major pathologic response had a 3-year actuarial DFS rate of 63%.

CONCLUSIONS

The patterns of pathologic response after preoperative ChRT suggest encouraging intervals of DFS. Such a strategy may be of interest to be explored in gastric cancer.

Downstaging without complete pathologic response after neoadjuvant treatment improves cancer outcomes for cIII but not cII rectal cancers

BACKGROUND

The aim of this study was to evaluate whether downstaging impacts prognosis in patients with cII versus cIII rectal cancer.

MATERIALS AND METHODS

We identified from our colorectal cancer database 295 patients with primary cII and cIII rectal cancer staged by CT and ERUS/MRI who received 5-FU-based chemoradiation followed by R0 surgery after a median interval of 7 weeks during 1997-2007. The median radiotherapy dose was 5040 cGy. We excluded 58 patients with pathologic complete response (pCR) and compared among the remaining 162 patients pathologic downstaging (cII to ypI, cIII to ypII or ypI) versus no pathologic downstaging (c stage < or = yp stage). Outcomes evaluated were 5-year overall survival, 3-year cancer-specific survival, disease-free survival, overall recurrence, local recurrence, and distant recurrence.

RESULTS

The median age was 58 years and median follow-up was 48 months. Patients with downstaging versus no downstaging were statistically comparable with respect to demographics, chemoradiation regimen, interval time between neoadjuvant chemoradiation and surgery, tumor distance from anal verge, surgical procedures performed, and follow-up time. With the exception of local recurrence rates, downstaging resulted in significantly improved cancer outcomes for cIII but not cII.

CONCLUSIONS

Downstaging without pCR is a significant prognostic factor for patients with stage cIII rectal cancer. Tumor response to neoadjuvant chemoradiation should be taken into account when defining the optimal adjuvant chemotherapy regimen for patients with cIII rectal cancer.

Regression of rectal cancer with radiotherapy with or without concurrent capecitabine--optimising the timing of surgical resection

AIMS

To determine tumour regression (volume-halving time) obtained after chemo/radiotherapy, and thereby the ideal interval between the start of treatment and surgery in order to obtain a high rate of complete response.

MATERIALS AND METHODS

In total, 106 patients with cT3,4 rectal cancer who received preoperative radiotherapy alone or concurrently with capecitabine chemotherapy at Nottingham City Hospital, UK were studied. The rectal tumour volume visible on the computed tomography planning scan was compared with the residual pathological volume and the tumour volume-halving time calculated. The radiotherapy response was graded according to the Mandard system.

RESULTS

Fifty-three patients had radiotherapy alone, with 53 patients having concurrent chemoradiotherapy. The median tumour volume-halving time was found to be 14 days and not influenced by the addition of chemotherapy. The Mandard score, the interval from the start of treatment to surgery and the tumour volume-halving time were statistically associated with tumour regression. The median tumour volume in our series of 54 cm(3) would require an interval of 20 weeks after the start of treatment to surgery to regress to <0.1 cm(3) (10 volume-halving times; 140 days).

CONCLUSIONS

The initial tumour volume and median volume-halving time provide the best estimates for determining the optimum length of interval between the completion of preoperative chemo/radiotherapy and surgery in locally advanced rectal cancer.

Rectal cancer treatment: Improving the picture

Multidisciplinary approach for rectal cancer treatment is currently well defined. Nevertheless, new and promising advances are enriching the portrait. Since the US NIH Consensus in the early 90’s some new characters have been added. A bird’s-eye view along the last decade shows the main milestones in the development of rectal cancer treatment protocols. New drugs, in combination with radiotherapy are being tested to increase response and tumor control outcomes. However, therapeutic intensity is often associated with toxicity. Thus, innovative strategies are needed to create a better-balanced therapeutic ratio. Molecular targeted therapies and improved technology for delivering radiotherapy respond to the need for accuracy and precision in rectal cancer treatment.

Phase I trial of cetuximab in combination with capecitabine, weekly irinotecan, and radiotherapy as neoadjuvant therapy for rectal cancer

PURPOSE

To establish the feasibility and efficacy of chemotherapy with capecitabine, weekly irinotecan, cetuximab, and pelvic radiotherapy for patients with locally advanced rectal cancer.

METHODS AND MATERIALS

Twenty patients with rectal cancer (clinical Stage uT3-T4 or N+) received a standard dosing regimen of cetuximab (400 mg/m(2) on Day 1 and 250 mg/m(2) on Days 8, 15, 22, and 29) and escalating doses of irinotecan and capecitabine according to phase I methods: dose level I, irinotecan 40 mg/m(2) on Days 1, 8, 15, 22, and 29 and capecitabine 800 mg/m(2) on Days 1-38; dose level II, irinotecan 40 mg/m(2) and capecitabine 1000 mg/m(2); and dose level III, irinotecan 50 mg/m(2) and capecitabine 1000 mg/m(2). Radiotherapy was given to a dose of 50.4 Gy (45 Gy plus 5.4 Gy). Resection was scheduled 4-5 weeks after termination of chemoradiotherapy.

RESULTS

On dose level I, no dose-limiting toxicities occurred; however, Grade 3 diarrhea affected 1 of 6 patients on dose level II. Of 5 patients treated at dose level III, 2 exhibited dose-limiting toxicity (diarrhea in 2 and nausea/vomiting in 1). Therefore, dose level II was determined as the recommended dose for future studies. A total of 10 patients were treated on dose level II and received a mean relative dose intensity of 100% of cetuximab, 94% of irinotecan, and 95% of capecitabine. All patients underwent surgery. Five patients had a pathologically complete remission and six had microfoci of residual tumor only.

CONCLUSION

Preoperative chemoradiotherapy with cetuximab, capecitabine, and weekly irinotecan is feasible and well tolerated. The preliminary efficacy is very promising. Larger phase II trials are ongoing.