T-level downstaging and complete pathologic response after preoperative chemoradiation for advanced rectal cancer result in decreased recurrence and improved disease-free survival

Prognostic Role of Neutrophil-to-Lymphocyte Ratio in Locally Advanced Rectal Cancer Treated with Neoadjuvant Chemoradiotherapy

Background

Increasing evidence suggests that cancer-associated inflammation is associated with poorer outcomes. The neutrophil-to-lymphocyte ratio (NLR), considered as a systemic inflammation marker, is thought to predict prognoses in colorectal cancer. In this study, we explored the association between the NLR and prognoses following neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC).

Material/Methods

From February 2002 to December 2012, a group of 202 patients diagnosed with LARC and receiving neoadjuvant CRT followed by radical surgery was included in our retrospective study. The associations between the pre-CRT NLR and clinicopathological characteristics, as well as the predictive value of pre-CRT NLR against survival outcomes, were analyzed.

Results

The average NLR was 2.7±1.5 (median 2.4, range 0.6–12.8). There were 63 (31.2%) patients with NLR ≥3.0, and 139 (68.8%) patients with NLR <3.0. Correlation analyses showed that no clinicopathological characteristics except age were associated with NLR. We did not find an association between NLR and survival outcomes. In multivariate Cox model analyses, the R1/R2 resection, lymph node ratio ≥0.1, and perineural/lymphovascular invasion were independently associated with worse disease-free survival and overall survival.

Conclusions

In our cohort, the NLR did not correlate with survival outcomes in LARC patients undergoing neoadjuvant CRT. The prognostic value of NLR should be validated in large-scale prospective studies.

Pathologic response to neoadjuvant treatment in locally advanced rectal cancer and impact on outcome

BACKGROUND

Downstaging and pathologic complete response (pCR) after chemoradiotherapy (CRT) may improve progression-free survival and overall survival (OS) after curative therapy of locally advanced adenocarcinoma of rectum. The purpose of this study is to evaluate the pathologic response subsequent to neoadjuvant chemoradiation in locally advanced rectal adenocarcinoma and any impact of response on oncological outcome [disease-free survival (DFS), OS].

METHODS

A total of 127 patients with histologically-proven rectal adenocarcinoma, locally advanced, were treated with preoperative radiotherapy and concurrent 5-fluorouracil (5 FU), and followed by curative surgery. Pathologic response to neoadjuvant treatment was evaluated by comparing pathologic TN (tumour and nodal) staging (yp) with pre-treatment clinical staging. DFS and OS were compared in patients with: pCR, partial pathologic response and no response to neoadjuvant therapy.

RESULTS

14.96% (19 patients) had a pCR, 58.27% [74] showed downstaging and 26.77% [34] had no change in staging. At follow-up (range, 4-9 years, median 6 years 2 months or 74 months), 17.32% [22] showed recurrence: 15.74% [20] distant metastasis, 1.57% [2] pelvic failure. 10.5% [2] of the patients with pCR showed distant metastasis, none showed local recurrence. In the downstaged group, nine developed distant failure and two had local recurrence (14.86%). Distant failure was seen in 26.47% [9] of those with no response to neoadjuvant treatment. DFS and OS rates for all groups were 82.67% and 88.97% respectively. Patients with pCR showed 89.47% DFS and 94.7% OS. In partial responders, DFS was 85.1% and OS was 90.5%. In non-responders, DFS and OS were 73.5% and 82.3% respectively. Patients with pCR had a significantly greater probability of DFS and OS than non-responders. Rectal cancer-related death was 11.02% [14]: one patient (5.26%) with pCR, 9.47% [7] in the downstaged group and 17.64% [6] of non-responders.

CONCLUSIONS

The majority of patients showed some response to neoadjuvant treatment. Findings of this study indicate tumour response to neoadjuvant CRT improves the long-term outcome, with a better result in patients with pCR.

Multivisceral resections for rectal cancers: short-term oncological and clinical outcomes from a tertiary-care center in India

BACKGROUND

Locally advanced rectal cancers (LARCs) involve one or more of the adjacent organs in upto 10-20% patients. The cause of the adhesions may be inflammatory or neoplastic, and the exact causes cannot be determined pre- or intra-operatively. To achieve complete resection, partial or total mesorectal excision (TME) en bloc with the involved organs is essential. The primary objective of this study is to determine short-term oncological and clinical outcomes in these patients undergoing multivisceral resections (MVRs).

METHODS

This is a retrospective review of a prospectively maintained database. Between 1 July 2013 and 31 May 2015, all patients undergoing MVRs for adenocarcinoma of the rectum were identified from this database. All patients who had en bloc resection of an adjacent organ or part of an adjacent organ were included. Those with unresectable metastatic disease after neoadjuvant therapy were excluded.

RESULTS

Fifty-four patients were included in the study. Median age of the patients was 43 years. Mucinous histology was detected in 29.6% patients, and signet ring cell adenocarcinoma was found in 24.1% patients. Neoadjuvant therapy was given in 83.4% patients. R0 resection was achieved in 87% patients. Five-year overall survival (OS) was 70% for the entire cohort of population.

CONCLUSIONS

In Indian subcontinent, MVRs in young patients with high proportion of signet ring cell adenocarcinomas based on magnetic resonance imaging (MRI) of response assessment (MRI 2) is associated with similar circumferential resection margin (CRM) involvement and similar adjacent organ involvement as the western patients who are older and surgery is being planned on MRI 1 (baseline pelvis). However, longer follow-up is needed to confirm noninferiority of oncological outcomes.

Focal adhesion kinase: predictor of tumour response and risk factor for recurrence after neoadjuvant chemoradiation in rectal cancer

Rectal cancer represents about 30% of colorectal cancers, being around 50% locally advanced at presentation. Chemoradiation (CRT) followed by total mesorectal excision is the standard of care for these locally advanced stages. However, it is not free of adverse effects and toxicity and the complete pathologic response rate is between 10% and 30%. This makes it extremely important to define factors that can predict response to this therapy. Focal adhesion kinase (FAK) expression has been correlated with worse prognosis in several tumours and its possible involvement in cancer radio‐ and chemosensitivity has been suggested; however, its role in rectal cancer has not been analysed yet. To analyse the association of FAK expression with tumour response to CRT in locally advanced rectal cancer. This study includes 73 patients with locally advanced rectal cancer receiving standard neoadjuvant CRT followed by total mesorectal excision. Focal adhesion kinase protein levels were immunohistochemically analysed in the pre‐treatment biopsies of these patients and correlated with tumour response to CRT and patients survival. Low FAK expression was significantly correlated with local and distant recurrence (P = 0.013). Low FAK expression was found to be a predictive marker of tumour response to neoadjuvant therapy (P = 0.007) and patients whose tumours did not express FAK showed a strong association with lower disease‐free survival (P = 0.01). Focal adhesion kinase expression predicts neoadjuvant CRT response in rectal cancer patients and it is a clinically relevant risk factor for local and distant recurrence.

A novel histologic grading scheme based on poorly differentiated clusters is applicable to treated rectal cancer and is associated with established histopathological prognosticators

The conventional histologic grading of colorectal cancer (CRC) is less suited for resected rectal cancer following neoadjuvant chemoradiation. Enumeration of poorly differentiated clusters (PDC) is a recently proposed histologic grading scheme. We aimed to apply PDC grading to treated rectal cancer and to test the prognostic significance of this novel approach. Archived hematoxylin and eosin slides of 72 rectal adenocarcinomas resected following neoadjuvant treatment were retrieved. PDC, tumor budding, and tumor regression were assessed. The parameters were correlated with clinicopathological features and survival. PDC was strongly associated with tumor budding, perineural invasion (PNI), metastasis, and low degree of tumor regression. Tumor budding was significantly associated with lymphovascular invasion and PNI, and metastasis. Tumors with a lower degree of regression were more likely to show high pathologic T stage and advanced clinical stage. Local recurrence was associated with poor survival. PDC did not correlate with overall survival. PDC grading is applicable to resected rectal cancer status post neoadjuvant treatment and correlates with established histopathological prognosticators. PDC and tumor budding may represent a histologic spectrum reflective of the same biological significance. Validation and incorporation of these simple histologic grading schemes may strengthen the prognostic power of the histologic parameters that influence the oncologic outcome in treated rectal cancer. Further study to evaluate the significance of PDC as an oncologic prognosticator is warranted.

Clinical Trial of Oral Nelfinavir before and during Radiation Therapy for Advanced Rectal Cancer

PURPOSE

Nelfinavir, a PI3K pathway inhibitor, is a radiosensitizer that increases tumor blood flow in preclinical models. We conducted an early-phase study to demonstrate the safety of nelfinavir combined with hypofractionated radiotherapy (RT) and to develop biomarkers of tumor perfusion and radiosensitization for this combinatorial approach.

EXPERIMENTAL DESIGN

Ten patients with T3-4 N0-2 M1 rectal cancer received 7 days of oral nelfinavir (1,250 mg b.i.d.) and a further 7 days of nelfinavir during pelvic RT (25 Gy/5 fractions/7 days). Perfusion CT (p-CT) and DCE-MRI scans were performed pretreatment, after 7 days of nelfinavir and prior to the last fraction of RT. Biopsies taken pretreatment and 7 days after the last fraction of RT were analyzed for tumor cell density (TCD).

RESULTS

There were 3 drug-related grade 3 adverse events: diarrhea, rash, and lymphopenia. On DCE-MRI, there was a mean 42% increase in medianKtrans, and a corresponding median 30% increase in mean blood flow on p-CT during RT in combination with nelfinavir. Median TCD decreased from 24.3% at baseline to 9.2% in biopsies taken 7 days after RT (P= 0.01). Overall, 5 of 9 evaluable patients exhibited good tumor regression on MRI assessed by tumor regression grade (mrTRG).

CONCLUSIONS

This is the first study to evaluate nelfinavir in combination with RT without concurrent chemotherapy. It has shown that nelfinavir-RT is well tolerated and is associated with increased blood flow to rectal tumors. The efficacy of nelfinavir-RT versus RT alone merits clinical evaluation, including measurement of tumor blood flow.

Neoadjuvant chemotherapy-related histologic changes in radical cystectomy: assessment accuracy and prediction of response

We evaluated the spectrum of histologic changes associated with neoadjuvant chemotherapy (NAC) and compared them with those resulting from transurethral resection (TUR). Twenty-five patients who received NAC were divided based on both their preoperative clinical/radiographic findings (clinical stage, hydronephrosis, palpable mass) and the cystectomy (RC) findings into NAC respondents (advanced clinical stage and <pT2+pN0), possible NAC respondents (non-advanced clinical stage and <pT2+pN0), and NAC nonrespondents (≥pT2and/or ≥pN1). In addition, 14 patients who received TUR alone and had <pT2+pN0 on RC were included. Presence/absence of the following histologic features was assessed: fibrosis/myofibroblastic reaction, hyalinization in the bladder wall, inflammatory reaction, calcification, foreign-body giant cells, necrosis, sheets of foamy macrophages, and fibrosis/hyalinization/necrosis in the lymph nodes (LNs). Overall, there was a significant histologic overlap between all groups. However, patients who received NAC had a significantly higher likelihood of showing hyalinization and less giant cells and inflammatory reaction than did those who received TUR only. Moreover, the only significantly different histologic features in NAC respondents versus TUR respondents were hyalinization and LN changes, with those 2 features in 25% and 0% of the possible NAC respondents group, respectively. Lastly, there was no significant difference in the possible NAC respondent group in comparison to the TUR-only arm. It appears that TUR and NAC result in overlapping histologic changes. In cases with no/minimal residual disease on RC, it is difficult to attribute the changes to NAC effect only, except if (1) hyalinization of the bladder wall or LN changes are present, or (2) if the preoperative clinical stage was beyond what could be resected by TUR.

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.

NPTX2 is associated with neoadjuvant therapy response in rectal cancer

BACKGROUND

Neoadjuvant chemoradiation (CRT) is recommended for locally advanced rectal cancer. Tumor response varies from pathologic complete response (pCR) to no tumor regression. The mechanisms behind CRT resistance remain undefined. In our previously generated complementary DNA microarrays of pretreatment biopsies from rectal cancer patients, neuronal pentraxin 2 (NPTX2) expression discriminated patients with pCR from those with residual tumor. As tumor response is prognostic for survival, we sought to evaluate the clinical relevance of NPTX2 in rectal cancer.

MATERIALS AND METHODS

Real-time quantitative polymerase chain reaction was used to evaluate NPTX2 messenger RNA expression in individual rectal cancers before CRT. Tumors with NPTX2 expression <50% of normal rectum were defined as NPTX2-low and those with >50% were defined as NPTX2-high. NPTX2 levels were compared to response to therapy and oncologic outcomes using Mann-Whitney, Kruskal-Wallis, chi-square, and Mantel-Cox (log-rank) tests, as appropriate.

RESULTS

Rectal cancers from 40 patients were included. The mean patient age was 56.8 years, and 30% were female. pCR was achieved in eight of 40 patients (20%). In these patients, messenger RNA NPTX2 levels were significantly decreased compared to those with residual cancer (fold change 30.4, P = 0.017). Patients with NPTX2-low tumors (n = 13) achieved improved response to treatment (P = 0.012 versus NPXT2-high tumors), with 38.5% and 46.1% of patients achieving complete or moderate response, respectively. Of patients with NPTX2-high tumors (n = 27), 11.1% and 18.5% achieved complete or moderate response, respectively. No recurrence or death was recorded in patients with NPTX2-low tumors, reflecting more favorable disease-free survival (P = 0.045).

CONCLUSIONS

Decreased NPTX2 expression in rectal adenocarcinomas is associated with improved response to CRT and improved prognosis. Further studies to validate these results and elucidate the biological role of NPTX2 in rectal cancer are needed.

Diffusion-weighted imaging: Apparent diffusion coefficient histogram analysis for detecting pathologic complete response to chemoradiotherapy in locally advanced rectal cancer

PURPOSE

To investigate the usefulness of apparent diffusion coefficient (ADC) values derived from histogram analysis of the whole rectal cancer as a quantitative parameter to evaluate pathologic complete response (pCR) on preoperative magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We enrolled a total of 86 consecutive patients who had undergone surgery for rectal cancer after neoadjuvant chemoradiotherapy (CRT) at our institution between July 2012 and November 2014. Two radiologists who were blinded to the final pathological results reviewed post-CRT MRI to evaluate tumor stage. Quantitative image analysis was performed using T2 -weighted and diffusion-weighted images independently by two radiologists using dedicated software that performed histogram analysis to assess the distribution of ADC in the whole tumor.

RESULTS

After surgery, 16 patients were confirmed to have achieved pCR (18.6%). All parameters from pre- and post-CRT ADC histogram showed good or excellent agreement between two readers. The minimum, 10th, 25th, 50th, and 75th percentile and mean ADC from post-CRT ADC histogram were significantly higher in the pCR group than in the non-pCR group for both readers. The 25th percentile value from ADC histogram in post-CRT MRI had the best diagnostic performance for detecting pCR, with an area under the receiver operating characteristic curve of 0.796.

CONCLUSION

Low percentile values derived from the ADC histogram analysis of rectal cancer on MRI after CRT showed a significant difference between pCR and non-pCR groups, demonstrating the utility of the ADC value as a quantitative and objective marker to evaluate complete pathologic response to preoperative CRT in rectal cancer. J. Magn. Reson. Imaging 2016;44:212-220.

The accuracy of MRI, endorectal ultrasonography, and computed tomography in predicting the response of locally advanced rectal cancer after preoperative therapy: A metaanalysis

BACKGROUND

To perform a metaanalysis to determine and compare the diagnostic performance of MRI, endorectal ultrasonography (ERUS), and computed tomography (CT) in predicting the response of locally advanced rectal cancer after preoperative therapy.

METHODS

All previously published articles on the role of MRI, CT, and/or ERUS in predicting the response of rectal cancer to preoperative therapy were collected. We divided the objective in 3 parts: the accuracy to assess (i) complete response, (ii) to detect T4 tumors with invasion to the circumferential resection margin (CRM), and (iii) to predict the presence of lymph node metastasis. The pooled estimates of, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated using a bivariate mixed effect analysis.

RESULTS

Forty-six studies comprising 2,224 patients were included. (i) The pooled accuracy to assess complete tumor response were (a) 75% for MRI, (b) 82% for ERUS, (c) and 83% for CT. (ii) Pooled accuracy to detect T4 tumors with invasion to the CRM were (a) 88% and (b) 94% for ERUS. (iii) Pooled accuracy to predict the presence of lymph node metastasis was (a) 72% for MRI, (b) 72% for ERUS, (c) and 65% for CT.

CONCLUSION

MRI, CT, and ERUS cannot be used to predict complete response of locally advanced rectal cancer after CRT. In addition, the positive predictive value for these imaging techniques is low for the assessment of tumor invasion in the CRM. The accuracy of the modalities to predict the presence of metastatic lymph node disease is also low.

Pathologic Assessment of Rectal Carcinoma after Neoadjuvant Radio(chemo)therapy: Prognostic Implications

Neoadjuvant radio(chemo)therapy is increasingly used in rectal cancer and induces a number of morphologic changes that affect prognostication after curative surgery, thereby creating new challenges for surgical pathologists, particularly in evaluating morphologic changes and tumour response to preoperative treatment. Surgical pathologists play an important role in determining the many facets of rectal carcinoma patient care after neoadjuvant treatment. These range from proper handling of macroscopic specimens to accurate microscopic evaluation of pathological features associated with patients' prognosis. This review presents the well-established pathological prognostic indicators and discusses challenging features in order to provide both surgical pathologists and treating physicians with a checklist that is useful in a neoadjuvant setting.

Comparison of oncologic outcomes of metastatic rectal cancer patients with or without neoadjuvant chemoradiotherapy

PURPOSE

The aim of this study is to evaluate the effect of neoadjuvant chemoradiotherapy in stage IV rectal cancer.

METHODS

Primary rectal cancer patients with synchronous distant metastases between September 2001 and August 2011 were enrolled. Of 86 patients, 40 patients underwent neoadjuvant chemoradiotherapy (RTX group) and the remaining 46 patients underwent postoperative systemic chemotherapy without radiotherapy (NRTX group). Sharp mesorectal excision according to tumor location was performed. Oncologic outcomes were compared.

RESULTS

The lower tumor location was more common in RTX group than NRTX group (60.0 vs. 28.3%, P = 0.003). Clinical T and N status and American Society of Anesthesiologist (ASA) score were similar in both groups. The incidence of pathologic LN metastases in the NRTX group was 93.5% compared with 70.0% in RTX group (P = 0.007). Pattern of distant metastasis was similar between groups. However, metastatectomy was frequently performed in RTX group than NRTX group (57.5 vs. 30.4%, P = 0.020). There was no statistical difference in local recurrence rate between groups (10.0% in RTX vs. 15.2% in NRTX, P = 0.470). The median PFS was similar in both groups (12.00 months in RTX vs. 12.00 months in NRTX, P = 0.768). The median OS between groups was also not different (24.00 months in RTX vs. 27.00 months in NRT, P = 0.510).

CONCLUSIONS

Neoadjuvant chemoradiotherapy may not affect local control and overall survival in locally advanced rectal cancer with distant metastasis.

Locally advanced rectal cancer: post-chemoradiotherapy ADC histogram analysis for predicting a complete response

BACKGROUND

The value of diffusion-weighted imaging (DWI) for reliable differentiation between pathologic complete response (pCR) and residual tumor is still unclear. Recently, a few studies reported that histogram analysis can be helpful to monitor the therapeutic response in various cancer research.

PURPOSE

To investigate whether post-chemoradiotherapy (CRT) apparent diffusion coefficient (ADC) histogram analysis can be helpful to predict a pCR in locally advanced rectal cancer (LARC).

MATERIAL AND METHODS

Fifty patients who underwent preoperative CRT followed by surgery were enrolled in this retrospective study, non-pCR (n = 41) and pCR (n = 9), respectively. ADC histogram analysis encompassing the whole tumor was performed on two post-CRT ADC600 and ADC1000 (b factors 0, 600 vs. 0, 1000 s/mm(2)) maps. Mean, minimum, maximum, SD, mode, 10th, 25th, 50th, 75th, 90th percentile ADCs, skewness, and kurtosis were derived. Diagnostic performance for predicting pCR was evaluated and compared.

RESULTS

On both maps, 10th and 25th ADCs showed better diagnostic performance than that using mean ADC. Tenth percentile ADCs revealed the best diagnostic performance on both ADC600 (AZ 0.841, sensitivity 100%, specificity 70.7%) and ADC1000 (AZ 0.821, sensitivity 77.8%, specificity 87.8%) maps. In comparison between 10th percentile and mean ADC, the specificity was significantly improved on both ADC600 (70.7% vs. 53.7%; P = 0.031) and ADC1000 (87.8% vs. 73.2%; P = 0.039) maps.

CONCLUSION

Post-CRT ADC histogram analysis is helpful for predicting pCR in LARC, especially, in improving the specificity, compared with mean ADC.

Systematic review and meta-analysis of the accuracy of MRI and endorectal ultrasound in the restaging and response assessment of rectal cancer following neoadjuvant therapy

AIM

Restaging imaging by MRI or endorectal ultrasound (ERUS) following neoadjuvant chemoradiotherapy is not routinely performed, but the assessment of response is becoming increasingly important to facilitate individualization of management.

METHOD

A search of the MEDLINE and Scopus databases was performed for studies that evaluated the accuracy of restaging of rectal cancer following neoadjuvant chemoradiotherapy with MRI or ERUS against the histopathological outcome. A systematic review of selected studies was performed. The methodological quality of studies that qualified for meta-analysis was critically assessed to identify studies suitable for inclusion in the meta-analysis.

RESULTS

Sixty-three articles were included in the systematic review. Twelve restaging MRI studies and 18 restaging ERUS studies were eligible for meta-analysis of T-stage restaging accuracy. Overall, ERUS T-stage restaging accuracy (mean [95% CI]: 65% [56-72%]) was nonsignificantly higher than MRI T-stage accuracy (52% [44-59%]). Restaging MRI is accurate at excluding circumferential resection margin involvement. Restaging MRI and ERUS were equivalent for prediction of nodal status: the accuracy of both investigations was 72% with over-staging and under-staging occurring in 10-15%.

CONCLUSION

The heterogeneity amongst restaging studies is high, limiting conclusive findings regarding their accuracies. The accuracy of restaging imaging is different for different pathological T stages and highest for T3 tumours. Morphological assessment of T- or N-stage by MRI or ERUS is currently not accurate or consistent enough for clinical application. Restaging MRI appears to have a role in excluding circumferential resection margin involvement.

Risk-Adapted Adjuvant Chemotherapy After Concomitant Fluoropyrimidine-Radiotherapy Neoadjuvant Treatment for Patients With Resectable CT3-4 or N+ Rectal Cancer: Five-Year Disease-Free Survival Results of a Single-Center Series

BACKGROUND

Providing adjuvant chemotherapy in locally advanced rectal cancer after neoadjuvant chemoradiation is currently a matter of debate. Recommendations from clinical guidelines range from offering no treatment to oxaliplatin-based combinations. We present a risk-adapted approach based on the response to initial chemoradiation as the strongest prognostic factor for disease-free survival (DFS).

PATIENTS AND METHODS

One hundred one patients were treated at a single institution with preoperative long-course radiotherapy plus concurrent fluoropyrimidines. Patients with disease downstaged to pT0-2N0 received adjuvant fluoropyrimidines alone, while the remaining received an oxaliplatin-based combination. The primary study end point was 5-year DFS.

RESULTS

Overall, the disease of 54 patients was downstaged to pT0-2N0 (53.5%), while that of 47 patients was staged as pT3-4 or N+ (46.5%) after surgery. In the intention-to-treat analysis, 5-year DFS for patients in the good-prognosis group (downstaging to pT0-2 N0) and for those with poor prognosis (pT3-4 or N+) were 79.4% and 66.3%, respectively (hazard ratio, 0.489; P = .043). Downstaging and pN+ were independent prognostic factors for DFS.

CONCLUSION

A risk-adapted adjuvant therapy strategy based on pathologic stage after neoadjuvant chemoradiation is feasible and achieves high rates of 5-year DFS. Patients with good prognostic factors can be treated with adjuvant fluoropyrimidines alone, thus permitting the avoidance of oxaliplatin-derived toxicities.

Multimodal Assessments Are Needed for Restaging after Neoadjunvant Chemoradiation Therapy in Rectal Cancer Patients

PURPOSE

Restaging after neoadjuvant treatment is done for planning the surgical approach and, increasingly, to determine whether additional therapy or resection can be avoided for selected patients.

MATERIALS AND METHODS

Local restaging after neoadjuvant chemoradiation therapy (nCRT) was performed in 270 patients with locally advanced (cT3or4 or N+) rectal cancer. Abdomen and pelvic computed tomography (APCT) was used in all 270 patients, transrectal ultrasound (TRUS) in 121 patients, and rectal magnetic resonance imaging (MRI) in 65 patients. Findings according to imaging modalities were correlated with pathologic stage using Cohen's kappa (κ) to test agreement and intra-class correlation coefficient α to test reliability.

RESULTS

Accuracy for prediction of ypT stage according to three imaging modalities was 45.2% (κ=0.136, α=0.380) in APCT, 49.2% (κ=0.259, α=0.514) in rectal MRI, and 57.9% (κ=0.266, α=0.520) in TRUS. Accuracy for prediction of ypN stage was 66.0% (κ=0.274, α=0.441) in APCT, 71.8% (κ=0.401, α=0.549) in rectal MRI, and 66.1% (κ=0.147, α=0.272) in TRUS. Of 270 patients, 37 (13.7%) were diagnosed as pathologic complete responder after nCRT. Rectal MRI for restaging did not predict complete response. On the other hand, TRUS did predict three complete responders (κ=0.238, α=0.401).

CONCLUSION

APCT, rectal MRI, and TRUS are unreliable in restaging rectal cancer after nCRT. We think that multimodal assessment with rectal MRI and TRUS may be the best option for local restaging of locally advanced rectal cancer after nCRT.

Role of intraoperative frozen section for assessing distal resection margin after anterior resection

BACKGROUND AND AIMS

The use of neoadjuvant long-course chemoradiotherapy (LCRT), shorter distal safety margins (DSMs) and stapled or intersphincteric resections has increased sphincter preservation rates. While intraoperative frozen section (IOFS) is not mandatory, it helps achieve negative distal resection margins (DRMs). Our aim was to audit the role of IOFS for DRM assessment while performing sphincter-saving rectal surgery and to identify those subgroups that would benefit the most from IOFS analysis.

METHODS

Patients who underwent rectal cancer surgery between 2009 and 2013 were identified from a prospectively maintained database. Patients who intraoperatively underwent an IOFS for DRM assessment were included in the study. Factors associated with a positive margin on IOFS were analysed. The sensitivity and specificity of IOFS were also assessed.

RESULTS

Of 250 patients, who had an anterior resection with an IOFS, 12 had an involved DRM. Of these patients, eight were involved by adenocarcinoma, two by acellular mucin, one by moderate dysplasia and one by adenoma confirmed on paraffin section. Positive margins had a 100 % intervention rate. There were two false negative on IOFS. IOFS had a sensitivity of 85.17 % with a specificity of 100 % and a negative predictive value of 99.16 %. Specimens with a positive IOFS were lower rectal (P < 0.05), poorly differentiated and post LCRT locally advanced tumours.

CONCLUSIONS

IOFS to confirm negative DRM is recommended in lower rectal tumours irrespective of DSM. It can be considered for locally advanced post LCRT poorly differentiated mid rectal tumours and avoided for upper rectal tumours.

KRAS Mutation Status Is Not a Predictor for Tumor Response and Survival in Rectal Cancer Patients Who Received Preoperative Radiotherapy With 5-Fluoropyrimidine Followed by Curative Surgery

We evaluated the tumor response and survival according to the KRAS oncogene status in locally advanced rectal cancer. One hundred patients with locally advanced rectal cancer (cT3-4N0-2M0) received preoperative radiation of 50.4 Gy in 28 fractions with 5-fluorouracil and total mesorectal excision. Tumor DNA from each patient was obtained from pretreatment biopsy tissues. A Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation was found in 26 (26%) of the 100 patients. Downstaging (ypT0-2N0M0) rates after preoperative chemoradiotheray were not statistically different between the wild-type and mutant-type KRAS groups (30.8% vs 27.0%, P = 0.715, respectively). After a median follow-up time of 34 months, there was no statistically significant difference in the 3-year relapse-free survival (82.2% vs 82.6%, P = 0.512) and overall survival (94.7% vs 92.3%, P = 0.249) rates between wild-type and mutant-type KRAS groups, respectively. The KRAS mutation status does not influence the tumor response to the radiotherapy and survival in locally advanced rectal cancer patients who received preoperative chemoradiotherapy and curative surgery.

Oncologic results and prognostic predictors of patients with locally advanced rectal cancer showing ypN0 after radical surgery following neoadjuvant chemoradiotherapy

PURPOSE

Adjuvant chemotherapy is recommended for patients with locally advanced rectal cancer after radical surgery following neoadjuvant chemoradiotherapy (NCRT) regardless of the final pathologic stage. However, the efficacy of adjuvant chemotherapy in ypN0 patients remains controversial. The aim of this study was to evaluate the oncologic outcomes and analyze the prognostic factors for ypN0 patients in order to estimate prognosis and establish an effective adjuvant chemotherapy strategy for stage 0-II rectal cancers after radical surgery following NCRT.

METHODS

Between January 1999 and December 2009, the medical records of 202 patients who had been diagnosed with locally advanced rectal cancer, underwent radical surgery following NCRT, and showed ypN0 were retrospectively reviewed.

RESULTS

The median follow-up period was 60.5 months. The 5-year local recurrence rate was 3.1 %. The 5-year disease-free survival and 5-year overall survival were 86.3 and 86.9 %. Postirradiation T3-4 and abdominoperineal resection (APR) were the independent prognostic indicators for disease-free survival (p = 0.001, p = 0.003) and overall survival (p = 0.001, p = 0.002). Adjuvant chemotherapy improved local recurrence in the patient with ypT3-4 and patients who had undergone APR (p = 0.014, p = 0.002). APR affected local recurrence, disease-free survival, and overall survival of ypT3-4 patients (p = 0.013. 0.029, and 0.001) CONCLUSIONS: Postirradiation T3-4 and APR are the significant prognostic factors for ypN0. Further randomized prospective study is needed to evaluate the oncologic benefit of adjuvant chemotherapy in ypN0 patients, especially those with ypT3-4 and those having undergone APR, and to confirm which chemotherapeutic agent could improve the oncologic outcomes of patients poorly responding to NCRT.

Robotic versus laparoscopic surgery for mid or low rectal cancer in male patients after neoadjuvant chemoradiation therapy: comparison of short-term outcomes

The aim of our study was to compare short-term outcomes of robotic and laparoscopic sphincter-saving total mesorectal excision (TME) in male patients with mid-low rectal cancer (RC) after neadjuvant chemoradiotherapy (NCRT). The study was conducted as a retrospective review of a prospectively maintained database, and we analyzed 14 robotic and 65 laparoscopic sphincter saving TME (R-TME and L-TME, respectively) performed by one surgeon between 2005 and 2013. Patient characteristics, perioperative recovery, postoperative complications and and pathology results were compared between the two groups. The patient characteristics did not differ significantly between the two groups. Median operating time was longer in the R-TME than in the L-TME group (182 min versus 140 min). Only two conversions occurred in the L-TME group. No difference was found between groups regarding perioperative recovery and postoperative complication rates. The median number of harvested lymph nodes was higher in the RTME than in the L-TME group (32 versus 23, p = 0.008). The median circumferential margin (CRM) was 10 mm in the R-TME group, 6.5 mm in the L-TME group (p = 0.047. The median distal resection margin (DRM) was 27.5 mm in the R-TME, 15 mm in the L-TME group (p = 0.014). Macroscopic grading of the specimen in the R-TME group was complete in all patients. In the L-TME group, grading was complete in 52 (80%) and incomplete in 13 (20%) cases (p = 0.109). R-TME is a safe and feasible procedure that facilitates performing of TME in male patients with mid-low RC after NCRT.

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).

Reduced luminal circumference of tumors plays a key role in anorectal function during the early period after neoadjuvant chemoradiation therapy in rectal cancer patients

PURPOSE

The deterioration of anorectal function after neoadjuvant chemoradiation therapy (nCRT) combined with surgery for rectal cancer has not been well defined. The aim of this study was to evaluate the relationship between the tumor response to nCRT and changes in anorectal function during a short-term period after nCRT.

METHODS

We analyzed 100 consecutive patients with available preoperative anorectal manometry data, both before and after nCRT, from 2010 to 2013.

RESULTS

Comparing the manometric data before and after nCRT, the values reflecting rectal sensory function after nCRT was significantly lower than those before nCRT. However, in patients who experienced changed tumor morphology and a reduction in luminal circumferential ratio (LCIR) of tumor after nCRT, the values reflecting rectal sensory function were significantly less decreased after nCRT. On multivariate analysis, the reduction of LCIR after nCRT was a very important factor preventing the impairment of anorectal function during the short-term period in terms of the first rectal sensory threshold (RST) (P = 0.002), the RST of "desire to defecate" (P = 0.006), and rectal compliance (P = 0.003). Additionally, in linear regression analysis, the RST for the desire to defecate was positively affected by tumor morphology (P = 0.015) and the reduced LCIR (P = 0.025), and rectal compliance was positively affected by the reduced LCIR (P = 0.001).

CONCLUSION

The nCRT impaired significantly rectal sensory function during the short-term period after nCRT and before a radical operation. However, this reduced LCIR of tumors after nCRT may prevent or minimize impediments to anorectal function during the short-term period after nCRT.

Association of beclin 1 expression with response to neoadjuvant chemoradiation therapy in patients with locally advanced rectal carcinoma

Beclin 1 is an essential regulator of autophagy that is induced in response to cellular stress and serves to maintain cell survival in established tumors. We recently demonstrated that Beclin 1 suppression can sensitize colorectal cancer cells to radiation-induced DNA damage and apoptosis. Therefore, we hypothesized that the level of Beclin 1 expression may be associated with radiation sensitivity in vivo. We determined the association of Beclin 1 expression in pretreatment rectal cancer tissues with response to neoadjuvant chemoradiation in surgical resection specimens. Stages II and III (n = 96) rectal adenocarcinoma patients were treated with neoadjuvant chemoradiation followed by surgical resection with curative intent. Beclin 1 was analyzed by immunohistochemistry and the expression level was dichotomized at the median value with categorization into low and high groups. We identified 56 (58.3%) and 40 (41.7%) patients whose tumors had high- versus low-level Beclin 1 expression, respectively. Rectal cancers with high versus low Beclin 1 expression were significantly less likely to be downstaged after chemoradiation treatment (45% [25/55] vs. 58% [22/38]; p = 0.02). In a multivariable analysis adjusted for age, sex, histological grade and baseline tumor node metastasis (TNM) stage, the impact of Beclin 1 expression on tumor downstaging remained statistically significant (p = 0.03). The association of the level of Beclin 1 expression with the rate of tumor downstaging after chemoradiation is consistent with in vitro data, and suggests that Beclin 1 may be a predictive biomarker for the efficacy of chemoradiation in patients with rectal cancer.

Impression of prognosis regarding pathologic stage after preoperative chemoradiotherapy in rectal cancer

AIM: To ascertain pathologic stage as a prognostic indicator for rectal cancer patients receiving preoperative chemoradiotherapy (PCRT).

METHODS: Patients with mid- and low rectal carcinoma (magnetic resonance imaging - based clinical stage II or III) between 2000 and 2009 and treated with curative radical resection were identified. Patients were divided into two groups: PCRT and No-PCRT. Recurrence-free survival (RFS) was examined according to pathologic stage and addition of adjuvant treatment.

RESULTS: Overall, 894 patients were identified. Of these, 500 patients received PCRT. Adjuvant chemotherapy was delivered to 81.5% of the No-PCRT and 94.8% of the PCRT patients. Adjuvant radiotherapy was given to 29.4% of the patients in the No PCRT group. The 5-year RFS for the No-PCRT group was 92.6% for Stage I, 83.3% for Stage II, and 72.9% for Stage III. The 5-year RFS for the PCRT group was 95.2% for yp Stage 0, 91.7% for yp Stage I, 73.9% for yp Stage II, and 50.7% for yp Stage III.

CONCLUSION: Pathologic stage can predict prognosis in PCRT patients. 5-year RFS is significantly lower among PCRT patients than No-PCRT patients in pathologic stage II and III. These results should be taken into account when considering adjuvant treatment for patients treated with PCRT.

Risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy

PURPOSE

Perineal wounds after complete proctectomy are at risk for failure, with dramatic consequences on patients' health and quality of life. This study is aimed at identifying risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy.

METHODS

Data from 284 patients undergoing total proctectomy from 2002 to 2012 either at the University of Chicago Medical Center or the Catholic University of Rome Hospital were collected and analyzed.

RESULTS

Overall, the perineal wound complication rate was 21.8%. Successful conservative management was accomplished in 45.2% of cases. Complications occurred significantly more often in patients with a higher Charlson score index, with the diagnosis of rectal cancer, who had received preoperative radiation and who had a surgical drain placed at the time of initial surgery. Neoadjuvant radiation was the only significant risk factor at multivariate analysis (OR 4.40). In the rectal cancer subgroup, younger age, female gender, and preoperative radiation were predictors of wound complications. Based on that, a 3-point score (radiation, age, and gender (RAG)) was developed. Patients with a score of 3 had a 50% risk of developing a perineal wound complication.

CONCLUSIONS

Perineal wound complications are a common and burdensome problem after total proctectomy. Preoperative radiation is the single most significant and controllable risk factor predicting perineal wound failure. In the presence of multiple, non-modifiable risk factors, alternative approaches to primary closure should be considered in managing complex perineal defects.

American Joint Committee on Cancer and College of American Pathologists regression grade: a new prognostic factor in rectal cancer

BACKGROUND

The American Joint Committee on Cancer and the College of American Pathologists provide guidelines for reporting pathologic response to neoadjuvant treatment of rectal cancer. The clinical relevance of these tumor regression grading guidelines is undefined.

OBJECTIVE

This study evaluates the prognostic significance of the American Joint Committee on Cancer/College of American Pathologists regression grading.

DESIGN

This is a retrospective cohort study based on data from a prospectively maintained colorectal cancer database. The cohorts were defined by American Joint Committee on Cancer/College of American Pathologists tumor regression grade.

SETTING

This study was performed at a single tertiary referral center.

PATIENTS

Five hundred thirty-eight patients with primary rectal adenocarcinoma who underwent neoadjuvant therapy between 1992 and 2012 were identified.

MAIN OUTCOME MEASURES

The primary outcome measures were overall and disease-free survival, cancer-specific mortality, and cumulative recurrence rate.

RESULTS

Five hundred thirty-eight patients were included, 105 of whom (19.5%) were American Joint Committee on Cancer/College of American Pathologists grade 0, 153 patients (28.4%) were grade 1, 181 patients (33.6%) were grade 2, and 99 (18.4%) were grade 3. Kaplan-Meier analysis revealed that American Joint Committee on Cancer/College of American Pathologists grade was associated with significant differences in overall survival (p < 0.001), disease-free survival (p < 0.001), and cumulative recurrence (p < 0.001). No local recurrences were observed in American Joint Committee on Cancer/College of American Pathologists grade 0 patients. Five-year overall survival rates were 89%, 74%, 63%, and 40% (p < 0.001); 5-year disease-free survival rates were 85%, 64%, 54%, and 33% (p < 0.001); and 5-year recurrence rates were 7%, 18%, 25%, and 33% (p <0.001) for American Joint Committee on Cancer/College of American Pathologists grades 0, 1, 2, and 3. After adjusting for significant covariates, including pathologic stage, American Joint Committee on Cancer/College of American Pathologists grade remained an independent predictor of overall survival (p < 0.001), disease-free survival (p < 0.001), and cumulative recurrence (p < 0.001) in Cox regression analyses.

LIMITATIONS

This was a retrospective study. There was a low local recurrence rate in our population, limiting the sensitivity of recurrence analyses.

CONCLUSIONS

This is the first study to delineate American Joint Committee on Cancer/College of American Pathologists regression grade as an independent oncologic prognostic factor. This information can be used in discussions with patients who have rectal cancer.

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.

Neutrophil-lymphocyte ratio predicts pathologic tumor response and survival after preoperative chemoradiation for rectal cancer

Background

Neutrophil-lymphocyte ratio (NLR) reflects the balance between pro- and anti-tumor immune activities. We evaluated whether NLR is associated with pathologic tumor response and prognosis in rectal cancer patients that underwent preoperative chemoradiaton therapy (CRT) with surgery.

Methods

One hundred two patients with rectal cancer that were treated by preoperative CRT followed by surgery were enrolled. A total of 50.4 GY of radiation and 5-FU-based chemotherapy were delivered. An NLR ≥ 3 was considered to be elevated. Pathologic tumor response based on ypTNM stage was categorized into two groups, good response (n = 35, pathologic complete response and ypTNM I) and poor response groups (n = 67, ypTNM II, III, and IV).

Results

Twenty-five patients (24.5%) had elevated NLR. Multivariate analysis showed that an elevated CEA level (p = 0.001), larger tumor (p = 0.03), and elevated NLR (p = 0.04) were significant predictors for a poor response. Poor pathological tumor response and elevated NLR were risk factors for cancer-specific and recurrence-free survivals.

Conclusion

An elevated NLR before CRT can be used as predictors for poor tumor response and unfavorable prognostic factors. Dominant pro-tumor activities of neutrophils or reduced anti-tumor immune response by lymphocytes, as determined by NLR, may have a impact on poor tumor response and unfavorable prognosis.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2482-14-94) contains supplementary material, which is available to authorized users.

Diffusion-weighted MRI and MR- volumetry--in the evaluation of tumor response after preoperative chemoradiotherapy in patients with locally advanced rectal cancer

PURPOSE

To determine the diagnostic performance of diffusion-weighted MRI and MR volumetry for the assessment of tumor response after preoperative chemoradiotherapy (CRT) in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

Forty-three patients with rectal cancer who underwent preoperative CRT were prospectively examined for the study. This prospective study was approved by our institutional review board. DW- and high resolution T2-weighted imaging were performed before and after therapy. Two different diffusion gradients (b = 0 and b = 600, then separately b = 0 and b = 1000) were applied. The mean tumor volume and mean ADC values were measured before and after therapy. To evaluate the responders and nonresponders to neoadjuvant CRT, two criteria, ypT stage determined in the pathologic examination after treatment and histopathologic tumor regression grade (Ryan), were used as reference standards. The patients with a lower ypT stage than T stage in the first MRI before neoadjuvant CRT were evaluated as the responder group, while the patients with a higher or the same ypT stage relative to the first MRI T stage were evaluated as the nonresponder group. According to Ryan tumor regression grade, grade 1 was evaluated as the responders, whereas grades 2 and 3 were evaluated as the nonresponder group. The percentage ADC increase and percentage tumor volume regression were compared between the responders and nonresponders using two reference standards: T downstaging and tumor regression grade (TRG).

RESULTS

Before CRT, the mean tumor ADC in the responder group was significantly lower than that in the nonresponder group (p < 0.001). At the end of CRT, the mean percentage of tumor ADC change in the responder group was significantly higher than that in the nonresponder group. The percentage tumor volume regression of the responders was significantly higher than that of the nonresponders (p = 0.001). The cut-off ADC value for discriminating between the responders and nonresponders after treatment was determined to be (b = 600) 1.03 × 10(-3)mm(2)/s and the sensitivity, 71%; specificity, 79%; accuracy, 74%; positive predictive value, 81%; negative predictive value, 68% respectively. The cut-off value for discriminating between the responders and the nonresponders after treatment was determined for b = 1000 as 1.20 × 10(-3)mm(2)/s and the sensitivity, 42%; specificity, 84%; accuracy, 60%; positive predictive value, 77%; negative predictive value, 53%.

CONCLUSION

The increase in the mean tumor ADC and percentage tumor volume regression in patients with rectal cancer treated with preoperative CRT was correlated with good response. DW MR imaging is a promising non-invasive technique that can help predict and monitor early therapeutic response in patients with rectal cancer who undergo CRT.

Statin use is not associated with improved progression free survival in cetuximab treated KRAS mutant metastatic colorectal cancer patients: results from the CAIRO2 study

Statins may inhibit the expression of the mutant KRAS phenotype by preventing the prenylation and thus the activation of the KRAS protein. This study was aimed at retrospectively evaluating the effect of statin use on outcome in KRAS mutant metastatic colorectal cancer patients (mCRC) treated with cetuximab. Treatment data were obtained from patients who were treated with capecitabine, oxaliplatin bevacizumab ± cetuximab in the phase III CAIRO2 study. A total of 529 patients were included in this study, of whom 78 patients were on statin therapy. In patients with a KRAS wild type tumor (n = 321) the median PFS was 10.3 vs. 11.4 months for non-users compared to statin users and in patients with a KRAS mutant tumor (n = 208) this was 7.6 vs. 6.2 months, respectively. The hazard ratio (HR) for PFS for statin users was 1.12 (95% confidence interval 0.78-1.61) and was not influenced by treatment arm, KRAS mutation status or the KRAS*statin interaction. Statin use adjusted for covariates was not associated with increased PFS (HR = 1.01, 95% confidence interval 0.71-1.54). In patients with a KRAS wild type tumor the median OS for non-users compared to statin users was 22.4 vs. 19.8 months and in the KRAS mutant tumor group the OS was 18.1 vs. 14.5 months. OS was significantly shorter in statin users versus non-users (HR = 1.54; 95% confidence interval 1.06-2.22). However, statin use, adjusted for covariates was not associated with increased OS (HR = 1.41, 95% confidence interval 0.95-2.10). In conclusion, the use of statins at time of diagnosis was not associated with an improved PFS in KRAS mutant mCRC patients treated with chemotherapy and bevacizumab plus cetuximab.

Association between the cytogenetic profile of tumor cells and response to preoperative radiochemotherapy in locally advanced rectal cancer

Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results.

Reduction in the size of enlarged pelvic lymph nodes after chemoradiation therapy is associated with fewer lymph node metastases in locally advanced rectal carcinoma

PURPOSE

We hypothesized that a reduction in the size of the lymph nodes after neoadjuvant therapy for locally advanced rectal carcinoma would be associated with decreased lymph node metastases and/or a better prognosis.

METHODS

Between March 2006 and April 2012, 71 patients with primary rectal cancer received neoadjuvant chemoradiation therapy (CRT). For all lymph nodes 5 mm or larger in size, the major and minor axes were measured on CT scan images, and the product was calculated. The lymph node size was determined before and after CRT. The patients were divided into three groups based on the lymph node size before and after treatment. Group A exhibited a reduction in size of 60% or more, Group B a reduction of less than 60% and Group C had no lymph node enlargement before treatment.

RESULTS

The incidence of lymph node metastases on pathological examination was 15% in Group A and 50% in Group B (p = 0.006). The five-year disease-free survival in Group A was 84% compared with 78% in Group B (log rank p = 0.34). The five-year overall survival in Group A was 92% compared with 74% in Group B (log rank p = 0.088).

CONCLUSIONS

A reduction in the size of enlarged lymph nodes after neoadjuvant therapy may be a useful prognostic factor for recurrence and survival.

Barium enema and CT volumetry for predicting pathologic response to preoperative chemoradiotherapy in rectal cancer patients

BACKGROUND

Preoperative chemoradiotherapy has been widely used for the prevention of local recurrence of locally advanced rectal cancer, and the effect of chemoradiotherapy is known to be associated with overall survival.

OBJECTIVE

We aimed to evaluate the association of the pathologic response grade with tumor recurrence rate after chemoradiotherapy, using radiographic analysis and the Response Evaluation Criteria in Solid Tumors as the parameters.

DESIGN

This study was conducted at a single tertiary care institution in Japan.

SETTING

This was a retrospective cohort study of patients undergoing preoperative chemoradiotherapy.

PATIENTS

A total of 101 low rectal cancer patients receiving preoperative chemoradiotherapy from July 2004 to August 2012 were enrolled.

MAIN OUTCOME MEASURES

The tumor reduction rate was measured with the use of traditional Response Evaluation Criteria in Solid Tumors, barium enema, and CT volumetry, and the correlation between the reduction rate and the pathologic response grade was examined.

RESULTS

The tumor reduction rate assessed according to Response Evaluation Criteria in Solid Tumors showed no association with the pathologic response grade (p =0.61). In contrast, the radiographic response rate by both barium enema and CT volumetry strongly correlated with the pathologic response grade (p < 0.0001 and p = 0.001).In terms of local tumor recurrence, those diagnosed as high responders by the pathologic response grade, Response Evaluation Criteria in Solid Tumors, barium enema, and CT volumetry had a lower recurrence rate (p =0.03, p =0.03, p =0.0002, and p =0.001). The difference between high responders and low responders was especially prominent by barium enema and CT volumetry.

LIMITATIONS

The study is limited by its retrospective nature.

CONCLUSIONS

Double-contrast barium enema and CT volumetry were superior to Response Evaluation Criteria in Solid Tumors in evaluating the effect of chemoradiotherapy and predicting the likelihood of tumor recurrence.

Wound dehiscence after abdominoperineal resection for low rectal cancer is associated with decreased survival

BACKGROUND

Abdominoperineal resection for low rectal adenocarcinoma is a common procedure with high morbidity, including perineal wound complications.

OBJECTIVE

The purpose of this study was to determine risk factors for perineal wound dehiscence and to investigate the effect of wound dehiscence on survival.

DESIGN

This was a retrospective medical chart review.

SETTINGS

The study was conducted in a tertiary care university medical center.

PATIENTS

Patients included in the study were those with low rectal adenocarcinoma who underwent abdominoperineal resection between January 2001 and June 2012.

MAIN OUTCOMES MEASURES

We assessed the incidence of perineal wound dehiscence, as well as survival, after surgery.

RESULTS

A total of 249 patients underwent abdominoperineal resection for rectal carcinoma. The mean age was 62.6 years (range, 23.0-98.0 years), 159 (63.8%) were male, and the mean BMI was 27.9 (range, 16.7-58.5). There were 153 patients (61.1%) who survived for 5 years after surgery. Sixty-nine patients (27.7%) developed wound dehiscence. Multivariable analysis revealed the following associations with dehiscence: BMI (OR, 1.09; 95% CI, 1.03-1.15; p = 0.002), IBD (OR, 6.6; 95% CI, 1.4-32.5; p = 0.02), history of other malignant neoplasm (OR, 3.1; 95% CI, 1.5-6.6), and abdominoperineal resection for cancer recurrence (OR, 2.8; 95% CI, 1.2-6.3; p = 0.01). In the survival analysis, wound dehiscence was associated with decreased survival (mean survival time for dehiscence vs no dehiscence, 66.6 months vs 76.6 months; p = 0.01). This relationship persisted in the multivariable analysis (HR, 1.7; 95% CI, 1.1-2.8; p = 0.02).

LIMITATIONS

This was a retrospective, observational study from a single center.

CONCLUSIONS

The adjusted risk of death was 1.7 times higher in patients who experienced dehiscence than in those who did not. Attention to perineal wound closure with consideration of flap creation should at least be given to patients with a history of malignant neoplasm, those with IBD, those with rectal cancer recurrence, and women undergoing posterior vaginectomy. Preoperative weight loss should also reduce dehiscence risk.

T4 rectal cancer: do we always need an exenteration?

The management of rectal cancer has changed dramatically over the last few decades. Due to improvements in the multimodality treatment and the introduction of neoadjuvant chemoradiation, previously irresectable tumours can nowadays be cured by extensive multivisceral resections. These highly complex operations are associated with significant morbidity and mortality. Due to optimization of chemoradiotherapy, the introduction of IORT, increasing knowledge of tumour pathology and patterns of recurrence the need for extensive surgery diminishes. The question arises which patients with T4 rectal cancer really need extensive surgery and who can safely be considered for an organ preserving approach.

Gene expression profile is associated with chemoradiation resistance in rectal cancer

AIM

Patients with rectal cancer who achieve a complete pathological response after preoperative chemoradiation (CRT) have an improved oncological outcome. Identifying factors associated with a lack of response could help our understanding of the underlying biology of treatment resistance. This study aimed to develop a gene expression signature for CRT-resistant rectal cancer using high-throughput nucleotide microarrays.

METHOD

Pretreatment biopsies of rectal adenocarcinomas were prospectively collected and freshly frozen according to an institutional review board-approved protocol. Total tumour mRNA was extracted and gene expression levels were measured using microarrays. Patients underwent proctectomy after completing standard long-course CRT and the resected specimens were graded for treatment response. Gene expression profiles for nonresponders were compared with those of responders. Differentially expressed genes were analyzed for functional significance using the Ingenuity Pathway Analysis (IPA) software.

RESULTS

Thirty-three patients treated between 2006 and 2009 were included. We derived 812-gene and 183-gene signatures separating nonresponders from responders. The classifiers were able to identify nonresponders with a sensitivity and specificity of 100% using the 812-gene signature, and sensitivity and specificity of 33% and 100% using the 183-gene signature. IPA canonical pathway analysis revealed a significant ratio of differentially expressed genes in the 'DNA double-strand break repair by homologous recombination' pathway.

CONCLUSION

Certain rectal cancer gene profiles are associated with poor response to CRT. Alterations in the DNA double-strand break repair pathway could contribute to treatment resistance and provides an opportunity for further studies.

Pathological complete response of advanced rectal cancer treated by preoperative chemoradiotherapy with oral tegafur-uracil and leucovorin: a case report

A rare case of pathological complete response of advanced rectal cancer treated by preoperative chemoradiotherapy (CRT) with oral tegafur-uracil and leucovorin is reported. A 73-year-old man with bloody stool was diagnosed with type 2 rectal cancer located 6 cm from the anal verge. Examination of biopsy specimens revealed moderately differentiated adenocarcinoma. Computed tomography scans showed no distant or lymph node metastases. With a diagnosis of advanced lower rectal cancer of T3N0M0 stage III according to the TNM classification, he underwent preoperative CRT with oral tegafur-uracil and leucovorin. He did not experience any adverse events due to CRT. An abdominal CT scan and colonoscopy after CRT demonstrated significant tumor reduction. Then, 63 days after CRT, he underwent laparoscopic-assisted low anterior resection and diverting ileostomy. Pathological examination revealed no residual cancer cells. During 15 months of follow-up after his ileostomy was taken down, the patient continued to do well without any signs of recurrence or metastasis. Preoperative CRT with tegafur-uracil and leucovorin may thus represent a safe, well-tolerated, and effective therapeutic strategy for patients with advanced rectal cancer.

Robotic versus laparoscopic surgery for mid-low rectal cancer after neoadjuvant chemoradiation therapy: comparison of oncologic outcomes

PURPOSE

Minimal invasive surgery for mid and low rectal cancer after neoadjuvant long-course chemoradiotherapy (LCRT) can be challenging. The aim of our study was to compare outcomes of laparoscopic and robotic resections in mid and low rectal cancers after LCRT.

METHODS

Between Jan 2006 and Dec 2010, all patients who underwent robotic or laparoscopic resections for mid and low rectal cancers after LCRT were identified from a prospective database. These patients received treatment (5FU-based chemotherapy, 50.4 Gy radiotherapy), as they were T3 or T4 and/or node + ve. Patients in the two groups were compared with respect to demographics, clinical safety, and oncological outcomes.

RESULTS

One hundred thirty-eight patients underwent rectal cancer resection after LCRT, either robotic (n = 74) or laparoscopic (n = 64). The patients in both groups were comparable in terms of demographics, distance of tumor from anal verge, and type of procedures. There were four (6.3 %) conversions in laparoscopic group and one (1.4 %) in the robotic group (p = 0.183). The morbidity rates in the laparoscopic and robotic group were 26.6 % and 16.2 %, respectively (p = 0.137). With a median follow up of 3 years, the local recurrence in the laparoscopic and robotic group was four (6.3 %) and two (2.7 %), respectively (p = 0.420). The 3-year overall survival rate for laparoscopic and robotic group was 92.1 and 90.0 %, respectively (p = 0.803). The 3-year disease-free survival was also comparable, 78.8 % (laparoscopic) versus 77.7 % (robotic) (p = 0.390).

CONCLUSION

With a median follow up of 3 years, robotic surgery for mid and low rectal cancer was associated with oncological outcomes comparable to laparoscopic surgery.

Statin therapy is associated with improved pathologic response to neoadjuvant chemoradiation in rectal cancer

BACKGROUND

Achieving a pathologic complete response to neoadjuvant chemoradiation improves prognosis in rectal cancer. Statin therapy has been shown to enhance the impact of treatment in several malignancies, but little is known regarding the impact on rectal cancer response to neoadjuvant chemoradiation.

OBJECTIVE

The purpose of this study was to determine whether statin use during neoadjuvant chemoradiation improves pathologic response in rectal cancer.

DESIGN

This was a retrospective cohort study based on data from a prospectively maintained colorectal cancer database. The 2 cohorts were defined by statin use during neoadjuvant chemoradiation.

SETTING

This study was performed at a single tertiary referral center.

PATIENTS

Four hundred seven patients with primary rectal adenocarcinoma who underwent neoadjuvant therapy then proctectomy between 2000 and 2012 were included. Ninety-nine patients (24.3%) took a statin throughout the entire course of neoadjuvant therapy.

MAIN OUTCOME MEASURES

The primary outcome measure was pathologic response to neoadjuvant chemoradiotherapy as defined by the American Joint Committee on Cancer tumor regression grading system, grades 0 to 3.

RESULTS

Patients in the statin cohort had a lower median regression grade (1 vs 2, p = 0.01) and were more likely to have a better response (grades 0-1 vs 2-3) than those not taking a statin (65.7% vs 48.7%, p = 0.004). Statin use remained a significant predictor of an American Joint Committee on Cancer grade 0 to 1 (OR, 2.25; 95% CI, 1.33-3.82) in multivariate analyses. Although statin use itself did not significantly improve oncologic outcomes, an American Joint Committee on Cancer grade 0 to 1 response was associated with statistically significant improvements in overall survival, disease-free survival, cancer-specific mortality, and local recurrence.

LIMITATIONS

This was a retrospective study and subject to nonrandomization of patients and incorporated patients on variable statin agents and doses.

CONCLUSIONS

Statin therapy is associated with an improved response of rectal cancer to neoadjuvant chemoradiation. These data provide the foundation for a prospective clinical trial.

Neither FDG-PET Nor CT can distinguish between a pathological complete response and an incomplete response after neoadjuvant chemoradiation in locally advanced rectal cancer: a prospective study

OBJECTIVE

To prospectively compare the ability of flourodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) to identify a pathological complete response (pCR) in patients with rectal cancer treated by chemoradiation.

BACKGROUND

A major obstacle in pursuing nonoperative management in patients with rectal cancer after chemoradiation is the inability to identify a pCR preoperatively.

METHODS

A total of 121 patients with rectal cancer were prospectively enrolled. FDG-PET scans and helical CT scans were obtained before and after neoadjuvant chemoradiation. Consensus readings of PET and CT scans were used to classify certainty of disease (5-point confidence rating scale). The ability of PET and CT scans to accurately distinguish a pCR (ypT0) from an incomplete response (ypT1-4) was estimated using the area under the receiver operating characteristic curve (AUC).

RESULTS

Of the 121 patients, 26 (21%) had a pCR. PET and CT scans were equally inadequate at distinguishing a pCR from an incomplete response (AUC = 0.64 for both, P = 0.97). Among the 26 patients with a pCR, 14 (54%) and 5 (19%) were classified as complete responders on PET and CT scans, respectively. Among the 95 patients with an incomplete pathological response, 63 (66%) and 90 (95%) were classified as incomplete responders on PET and CT scans, respectively. None of the individual PET parameters, including visual response score, mean standard uptake value (SUVmean), maximum SUV (SUVmax), and total lesion glycolysis, accurately distinguished a pCR (AUCs = 0.57-0.73).

CONCLUSIONS

Neither PET nor CT scans have adequate predictive value to be clinically useful in distinguishing a pCR from an incomplete response and, therefore, should not be obtained for the purpose of attempting to predict a pCR after neoadjuvant chemoradiation for rectal cancer.

Is there a benefit in using magnetic resonance imaging in the prediction of preoperative neoadjuvant therapy response in locally advanced rectal cancer?

OBJECTIVE

This meta-analysis aimed to evaluate the accuracy of magnetic resonance imaging (MRI) in predicting responses in patients with locally advanced rectal cancer after preoperative neoadjuvant therapy.

METHODS

Articles in English language relating to the accuracy of MRI for this utility were retrieved. Methodological quality was assessed by Quality Assessment of Diagnostic Accuracy Studies tool. Pooled estimation and subgroup analysis data were obtained by statistical analysis.

RESULTS

Fourteen studies involved 751 pathologically confirmed patients met the inclusion criteria. Methodological quality was relatively high. To predict histopathological response in locally advanced rectal cancer by MRI, the pooled sensitivity and specificity were 0.78 [95 % confidence intervals (CI), 0.65, 0.87] and 0.81 (95 % CI, 0.72, 0.87), respectively. Positive likelihood ratio and negative likelihood ratio were 4.1 (95 %CI, 2.9, 5.8) and 0.27 (95 % CI, 0.17, 0.43), respectively. Subgroup analysis showing that imaging was performed at 3.0 T MRI devices had higher pooled sensitivity (0.92, 95 % CI, 0.84, 1.00) than the subgroup of MRI with ≤1.5 T (0.68, 95 % CI, 0.53, 0.82) (p < 0.05).The sensitivity and specificity of T2-weighted imaging (T2WI) with diffusion-weighted imaging (DWI) were 0.92 (95 % CI, 0.81, 1.00) and 0.75 (95 % CI, 0.54, 0.95); those of T2WI alone were 0.64 (95 % CI, 0.47, 0.82) and 0.88 (95 % CI, 0.81, 0.94) (p > 0.05).

CONCLUSION

This meta-analysis indicates that MRI is an accurate tool in predicting pathologic response after preoperative therapy in patients with locally advanced rectal cancer. It is suggested to perform MRI by 3.0 T devices, which might be sensitive to identify responder. The addition of DWI to T2WI showed a non-significant improvement in sensitivity, which deserves further investigation.

Locally advanced rectal cancer: is diffusion weighted MRI helpful for the identification of complete responders (ypT0N0) after neoadjuvant chemoradiation therapy?

OBJECTIVES

To determine retrospectively the additional value of DWI-MRI toT2-MRI for predicting complete response (ypT0N0 = CR) after chemoradiation-therapy (CRT) in locally advanced rectal cancer.

METHODS

Seventy locally advanced rectal cancer patients underwent CRT followed by restaging MRI and resection. Two readers with different experience levels independently scored T2 images for CR and, in a second reading, combined T2 and DWI. A 5-point confidence-level score was used to generate ROC curves. Areas under the ROC curves (AUC) and interobserver agreement were compared for both readings. Histology served as reference standard.

RESULTS

The interobserver agreement increased after addition of DWI from 0.35 to 0.58 but the AUC improved only for the experienced reader (0.77 to 0.89, p = 0.005 vs. 0.74 to 0.70, p > 0.05). Sensitivity and NPV improved from 20-30 % to 40-70 %, respectively 88 % to 91-95 %. Specificity and PPV improved only for the experienced reader (87 to 93 % respectively 27 to 63 %).

CONCLUSION

Adding DWI to T2-MRI improves consistency between readers and has potential to improve readers' accuracy dependent on his/her experience. DWI could be of additional value, particularly in ruling out CR (high NPV), but considering the sub-optimal PPV one should be cautious about relying solely on MRI for the clinical decision to offer a wait-and-see strategy.