Adjuvant chemotherapy may improve disease-free survival in patients with rectal cancer positive for MRI-detected extramural venous invasion following chemoradiation

AIM

MRI-detected extramural venous invasion (mrEMVI) is a poor prognostic factor in rectal cancer. Preoperative chemoradiotherapy (CRT) can cause regression in the severity of EMVI and subsequently improve survival whereas mrEMVI persisting after CRT confers an increased risk of recurrence. The effect of adjuvant chemotherapy (AC) following CRT on survival in rectal cancer remains unclear. The aim of this study was to determine whether there is a survival advantage for AC given to patients with mrEMVI persisting after CRT.

METHOD

A prospective analysis was conducted of consecutive patients with locally advanced rectal cancer between 2006 and 2013. All patients underwent CRT followed by surgery. AC was given to selected patients based on the presence of specific 'high-risk' features. Comparison was made between patients offered AC with observation alone. The primary outcome was 3-year disease-free survival (DFS).

RESULTS

Of 631 patients, 227 (36.0%) demonstrated persistent mrEMVI following CRT. Patients were grouped on the basis of AC or observation and were matched for age, performance status and final histopathological staging. Three-year DFS in the AC group was 74.6% compared with 53.7% in the observation only group. AC had a survival benefit on multivariate analysis (hazard ratio 0.458; 95% CI: 0.271-0.775, P = 0.004).

CONCLUSION

Patients with persistent mrEMVI following CRT who receive AC may have a decreased risk of recurrence and an improved 3-year DFS compared with patients not receiving AC, irrespective of age and performance status.

Microbiological problems and biofilms associated with Mycobacterium chimaera in heater-cooler units used for cardiopulmonary bypass

The role of heater-cooler units (HCUs) in the transmission of Mycobacterium chimaera during open heart surgery has been recognized since 2013. Subsequent investigations uncovered a remarkable global outbreak reflecting the wide distribution of implicated devices. HCUs are an essential component of cardiopulmonary bypass operations and their withdrawal would severely affect capacity for life-saving cardiac surgery. However, studies have demonstrated that many HCUs are contaminated with a wide range of micro-organisms, including M. chimaera and complex biofilms. Whole genome sequencing of M. chimaera isolates recovered from one manufacturer's HCUs, worldwide, has demonstrated a high level of genetic similarity, for which the most plausible hypothesis is a point source contamination of the devices. Dissemination of bioaerosols through breaches in the HCU water tanks is the most likely route of transmission and airborne bacteria have been shown to have reached the surgical field even with the use of ultraclean theatre ventilation. Controlling the microbiological quality of the water circulating in HCUs and reducing biofilm formation has been a major challenge for many hospitals. However, enhanced decontamination strategies have been recommended by manufacturers, and, although they are not always effective in eradicating M. chimaera from HCUs, UK hospitals have not reported any new cases of M. chimaera infection since implementing these mitigation strategies. Water safety groups in hospitals should be aware that water in medical devices such as HCUs may act as a vector in the transmission of potentially fatal water-borne infections.

Interobserver agreement of radiologists assessing the response of rectal cancers to preoperative chemoradiation using the MRI tumour regression grading (mrTRG)

AIM

To investigate whether the magnetic resonance imaging (MRI) tumour regression grading (mrTRG) scale can be taught effectively resulting in a clinically reasonable interobserver agreement (>0.4; moderate to near perfect agreement).

MATERIALS AND METHODS

This study examines the interobserver agreement of mrTRG, between 35 radiologists and a central reviewer. Two workshops were organised for radiologists to assess regression of rectal cancers on MRI staging scans. A range of mrTRGs on 12 patient scans were used for assessment.

RESULTS

Kappa agreement ranged from 0.14-0.82 with a median value of 0.57 (95% CI: 0.37-0.77) indicating good overall agreement. Eight (26%) radiologists had very good/near perfect agreement (κ>0.8). Six (19%) radiologists had good agreement (0.8≥κ>0.6) and a further 12 (39%) had moderate agreement (0.6≥κ>0.4). Five (16%) radiologists had a fair agreement (0.4≥κ>0.2) and two had poor agreement (0.2>κ). There was a tendency towards good agreement (skewness: 0.92). In 65.9% and 90% of cases the radiologists were able to correctly highlight good and poor responders, respectively.

CONCLUSIONS

The assessment of the response of rectal cancers to chemoradiation therapy may be performed effectively using mrTRG. Radiologists can be taught the mrTRG scale. Even with minimal training, good agreement with the central reviewer along with effective differentiation between good and intermediate/poor responders can be achieved. Focus should be on facilitating the identification of good responders. It is predicted that with more intensive interactive case-based learning a κ>0.8 is likely to be achieved. Testing and retesting is recommended.

Adjuvant therapy decisions based on magnetic resonance imaging of extramural venous invasion and other prognostic factors in colorectal cancer

INTRODUCTION

There remains a lack of high quality randomised trial evidence for the use of adjuvant chemotherapy in stage II rectal cancer, particularly in the presence of high risk features such as extramural venous invasion (EMVI). The aim of this study was to explore this issue through a survey of colorectal surgeons and gastrointestinal oncologists.

METHODS

An electronic survey was sent to a group of colorectal surgeons who were members of the Association of Coloproctology of Great Britain and Ireland. The survey was also sent to a group of gastrointestinal oncologists through the Pelican Cancer Foundation. Reminder emails were sent at 4 and 12 weeks.

RESULTS

A total of 142 surgeons (54% response rate) and 99 oncologists (68% response rate) responded to the survey. The majority in both groups of clinicians thought EMVI was an important consideration in adjuvant treatment decision making and commented routinely on this in their multidisciplinary team meeting. Although both would consider treating patients on the basis of EMVI detected by magnetic resonance imaging, oncologists were more selective. Both surgeons and oncologists were prepared to offer patients with EMVI adjuvant chemotherapy but there was lack of consensus on the benefit.

CONCLUSIONS

This survey reinforces the evolution in thinking with regard to adjuvant therapy in stage II disease. Factors such as EMVI should be given due consideration and the prognostic information we offer patients must be more accurate. Historical data may not accurately reflect today's practice and it may be time to consider an appropriately designed trial to address this contentious issue.

A systematic review and meta-analysis evaluating the role of laparoscopic surgical resection of transverse colon tumours

OBJECTIVES

A meta-analysis of published literature comparing outcomes after laparoscopic resection (LR) with open resection (OR) for transverse colon tumours.

METHODS

Medline, PubMed, CINAHL, EMBASE and Cochrane were searched from inception to October 2013. The text words "minimally invasive", "keyhole surgery" and "transverse colon" were used in combination with the medical subject headings "laparoscopy" and "colon cancer". Outcome variables were chosen based upon whether the included articles reported results. A meta-analysis was performed to obtain a summative outcome.

RESULTS

Six comparatives involving 444 patients were analysed. Of them 245 patients were in the LR group and 199 in the OR group. There was a significant increase in operative time in the LR group compared with the OR group [random effects model: SMD = -0.65, 95% CI (-1.01, -0.30), z = -3.60, p < 0.001] but there was significant heterogeneity amongst trials (Q = 15.51, df = 5, p = 0.008, I(2) = 68). There was less blood loss in the LR group [fixed effects model: SMD = 0.70, 95% CI (0.47, 0.93), z = 6.01, p < 0.001] and patients returned to oral diet earlier [random effects model: SMD = 0.78, 95% CI (0.40, 1.16), z = 4.01, p < 0.001] and had a reduced time to functioning bowel [fixed effects model: SMD = 0.86, 95% CI (0.60, 1.11), z = 6.63, p < 0.001]. No difference was seen for overall morbidity (p = 0.76) or mortality (p = 0.58).

CONCLUSIONS

LR of transverse colon tumours is a safe and effective technique. Although there is an increase in operating time, operative and clinical outcomes of intraoperative blood loss and faster recovery are seen with laparoscopic procedures.

EMVI-positive stage II rectal cancer has similar clinical outcomes as stage III disease following pre-operative chemoradiotherapy

BACKGROUND

Stage II rectal cancers comprise a heterogeneous group, and there is significant variability in practise with regards to adjuvant chemotherapy; the survival benefit of chemotherapy is perceived to be <4% in these patients. However, in recent years, the emergence of additional prognostic factors such as extramural venous invasion (EMVI) suggests that there may be sub-stratification of stage II tumours and, further, we may be under-estimating the benefit adjuvant chemotherapy provides in high-risk patients. This study examined the outcomes of patients with stage II and III rectal cancer to determine whether EMVI status influences disease-free survival (DFS).

PATIENTS AND METHODS

An analysis of a prospectively maintained database was conducted of patients presenting with rectal cancer between 2006 and 2012. All patients underwent curative surgery and had no evidence of metastases at presentation. Clinicopathological factors were compared between stage II and III disease. The primary end point was 3-year DFS; univariate and multivariate analysis was carried out using Cox proportional hazards regression models; hazard ratios (HR) with 95% confidence intervals (CIs) were calculated.

RESULTS

Four hundred and seventy-eight patients were included: 233 stage II; 245 stage III. The prevalence of EMVI was 34.9%; 57 stage II patients (24.5%) and 110 stage III patients (44.9%). On multivariate analysis, only EMVI status was a significant factor for DFS. The adjusted HR for EMVI either alone or in combination with nodal involvement was 2.08 (95% CI 1.10-2.95) and 2.74 (95% CI 1.66-4.52), respectively.

CONCLUSION

EMVI is an independently poor prognostic factor for DFS for both stage II and stage III rectal cancer. These results demonstrate that there is risk-stratification within stage II tumours which affects prognosis. When discussing the use of adjuvant chemotherapy with patients that have EMVI-positive stage II tumours, these results provide evidence for a similarly increased risk of distant failure as stage III disease without venous invasion.

Increase in scarlet fever notifications in the United Kingdom, 2013/2014

Increases in scarlet fever above usual seasonal levels are currently being seen across the United Kingdom. Medical practitioners have been alerted to the exceptional increase in incidence. Given the potential for this to signal a population increase in invasive group A streptococcal disease, close monitoring of invasive disease is essential.

Improved microwave absorption in lightweight resin-based carbon foam by decorating with magnetic and dielectric nanoparticles

Carbon foam (CFoam) decorated with Fe₃O₄–ZnO nanoparticles significantly improved electromagnetic radiation shielding effectiveness which is mainly dominated by absorption component.

Extramural venous invasion is a potential imaging predictive biomarker of neoadjuvant treatment in rectal cancer

BACKGROUND

Extramural venous invasion (EMVI) is a poor prognostic factor in rectal cancer and identified on magnetic resonance imaging (MRI) (mrEMVI). The clinical relevance of improvement in mrEMVI following neoadjuvant therapy is unknown. This study aimed to demonstrate that regression of mrEMVI following neoadjuvant chemoradiotherapy (CRT) results in improved outcomes and mrEMVI can be used as an imaging biomarker.

METHODS

Retrospective analysis of prospectively collected data was conducted examining the staging and post-treatment MRIs of patients who had presented with EMVI-positive rectal cancer. All patients had undergone neoadjuvant CRT and curative surgery. Changes in mrEMVI were graded with a new MRI-based TRG scale-mr-vTRG; and related to disease-free survival (DFS). The study fulfilled Reporting Recommendations for Tumour Marker Prognostic Studies criteria for biomarkers.

RESULTS

Sixty-two patients were included. Thirty-five patients showed more than 50% fibrosis of mrEMVI (mr-vTRG 1-3); 3-year DFS 87.8% and 9% recurrence. Twenty-seven patients showed less than 50% fibrosis (mr-vTRG 4-5); 3-year DFS 45.8% with 44% recurrence - P<0.0001. On multivariate Cox-regression, only mr-vTRG 4-5 increased risk of disease recurrence - HR=5.748.

CONCLUSION

Patients in whom there has been a significant response of EMVI to CRT show improved DFS. Those patients with poor response should be considered for intensive treatment. As an imaging biomarker in rectal cancer, mrEMVI can be used.

Adjuvant chemotherapy improves overall survival after TME surgery in mucinous carcinoma of the rectum

INTRODUCTION

Mucinous tumours of the rectum are characterised by an abundance of extracellular mucin within the tumour complex. They are known to have a poor prognosis compared to non-mucinous adenocarcinomas. The effect of adjuvant chemotherapy on the survival outcomes of patients with mucinous cancer remains unclear. This study evaluated the 5-year overall survival of patients with mucinous rectal cancer following optimal TME surgery to determine whether adjuvant chemotherapy conferred a survival benefit.

METHODS

An analysis of a prospectively-maintained database was conducted of patients presenting with mucinous rectal cancer between 2000 and 2010. Patients with mucinous tumours were identified from final pathology reports of the surgical resection specimens. The primary outcome was 5-year overall survival; univariate and multivariate analysis was performed using Cox proportional hazards regression models.

RESULTS

A total of 191 patients were included for analysis with mean age of presentation 64.6 years (36-88 ± 11). On the fully adjusted multivariate model, EMVI status (HR 1.853, 95% CI 1.081-3.175) and not being given adjuvant chemotherapy (HR 2.888, 95% CI 1.801-4.633) were significant for disease recurrence. The 5-year overall survival for patients that had undergone adjuvant chemotherapy was 66.1% compared with 35.2% (Mantel Cox log-rank test - p < 0.0001).

CONCLUSION

This study demonstrates that adjuvant chemotherapy is an independent factor for improvement in overall survival in patients with mucinous adenocarcinoma. Therefore, patients who have undergone TME surgery for mucinous carcinoma of the rectum should be offered adjuvant chemotherapy even in the absence of other high-risk features for poor outcomes.