Optimisation of Organ Preservation treatment strategies in patients with rectal cancer with a good clinical response after neoadjuvant (chemo)radiotherapy: Additional contact X-ray brachytherapy versus eXtending the observation period and local excision (OPAXX) - protocol for two multicentre, parallel, single-arm, phase II studies

INTRODUCTION

Standard treatment for patients with intermediate or locally advanced rectal cancer is (chemo)radiotherapy followed by total mesorectal excision (TME) surgery. In recent years, organ preservation aiming at improving quality of life has been explored. Patients with a complete clinical response to (chemo)radiotherapy can be managed safely with a watch-and-wait approach. However, the optimal organ-preserving treatment strategy for patients with a good, but not complete clinical response remains unclear. The aim of the OPAXX study is to determine the rate of organ preservation that can be achieved in patients with rectal cancer with a good clinical response after neoadjuvant (chemo)radiotherapy by additional local treatment options.

METHODS AND ANALYSIS

The OPAXX study is a Dutch multicentre study that investigates the efficacy of two additional local treatments aiming at organ preservation in patients with a good, but not complete response to neoadjuvant treatment (ie near-complete response or a small residual tumour mass <3 cm). The sample size will be 168 patients in total. Patients will be randomised (1:1) between two parallel single-arm phase II studies: study arm 1 involves additional contact X-ray brachytherapy (an intraluminal radiation boost), while in study arm 2 the observation period is extended followed by a second response evaluation and optional transanal local excision. The primary endpoint of the study is the rate of successful organ preservation at 1 year following randomisation. Secondary endpoints include toxicity, morbidity, oncological and functional outcomes at 1 and 2 years of follow-up. Finally, an observational cohort study for patients who are not eligible for randomisation is conducted.

ETHICS AND DISSEMINATION

The trial protocol has been approved by the medical ethics committee of the Netherlands Cancer Institute (METC20.1276/M20PAX). Informed consent will be obtained from all participants. The trial results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05772923.

Coverage of Lateral Lymph Nodes in Rectal Cancer Patients with Routine Radiation Therapy Practice and Associated Locoregional Recurrence Rates

PURPOSE

Involved internal iliac and obturator lateral lymph nodes (LLNs) are a known risk factor for the occurrence of ipsilateral local recurrences (LLR) in rectal cancer. This study examined coverage of LLNs with routine radiation therapy practice in the Netherlands and associated LLR rates.

METHODS AND MATERIALS

Patients with a primary tumor ≤8 cm of the anorectal junction, cT3-4 stage, and at least 1 internal iliac or obturator LLN with short axis ≥5 mm who received neoadjuvant (chemo)radiation therapy, were selected from a national, cross-sectional study of patients with rectal cancer treated in the Netherlands in 2016. Magnetic resonance images and radiation therapy treatment plans were reviewed regarding segmented LLNs as gross tumor volume (GTV), location of LLNs within clinical target volume (CTV), and received proportion of the planned radiation therapy dose.

RESULTS

A total of 223 out of 3057 patients with at least 1 LLN ≥5 mm were selected. Of those, 180 (80.7%) LLNs were inside the CTV, of which 60 (33.3%) were segmented as GTV. Overall, 202 LLNs (90.6%) received ≥95% of the planned dose. Four-year LLR rates were not significantly higher for LLNs situated outside the CTV compared with those inside (4.0% vs 12.5%, P = .092) or when receiving <95% versus ≥95% of the planned radiation therapy dose (7.1% vs 11.3%, P = .843), respectively. Two of 7 patients who received a dose escalation of 60 Gy developed an LLR (4-year LLR rate of 28.6%).

CONCLUSIONS

This evaluation of routine radiation therapy practice showed that adequate coverage of LLNs was still associated with considerable 4-year LLR rates. Techniques resulting in better local control for patients with involved LLNs need to be explored further.

Locally recurrent rectal cancer: Oncological outcomes for patients with a pathological complete response after neoadjuvant therapy

BACKGROUND

For patients with locally recurrent rectal cancer, it is an ongoing pursuit to establish factors predicting or improving oncological outcomes. In locally advanced rectal cancer, a pCR appears to be associated with improved outcomes. The aim of this retrospective cohort study was to compare the oncological outcomes of patients with locally recurrent rectal cancer with and without a pCR.

METHODS

Patients who underwent neoadjuvant treatment and surgery for locally recurrent rectal cancer with curative intent between January 2004 and June 2020 at a tertiary referral hospital were analysed. Primary outcomes included overall survival, disease-free survival, metastasis-free survival, and local re-recurrence-free survival, stratified according to whether the patient had a pCR.

RESULTS

Of a total of 345 patients, 51 (14.8 per cent) had a pCR. Median follow-up was 36 (i.q.r. 16-60) months. The 3-year overall survival rate was 77 per cent for patients with a pCR and 51.1 per cent for those without (P < 0.001). The 3-year disease-free survival rate was 56 per cent for patients with a pCR and 26.1 per cent for those without (P < 0.001). The 3-year local re-recurrence-free survival rate was 82 and 44 per cent respectively (P < 0.001). Surgical procedures (for example soft tissue, sacrum, and urogenital organ resections) and postoperative complications were comparable between patients with and without a pCR.

CONCLUSION

This study showed that patients with a pCR have superior oncological outcomes to those without a pCR. It may therefore be safe to consider a watch-and-wait approach in highly selected patients, potentially improving quality of life by omitting extensive surgical procedures without compromising oncological outcomes.

A Multidisciplinary Approach for the Personalised Non-Operative Management of Elderly and Frail Rectal Cancer Patients Unable to Undergo TME Surgery

Despite it being the optimal curative approach, elderly and frail rectal cancer patients may not be able to undergo a total mesorectal excision. Frequently, no treatment is offered at all and the natural course of the disease is allowed to unfold. These patients are at risk for developing debilitating symptoms that impair quality of life and require palliative treatment. Recent advancements in non-operative treatment modalities have enhanced the toolbox of alternative treatment strategies in patients unable to undergo surgery. Therefore, a proposed strategy is to aim for the maximal non-operative treatment, in an effort to avoid the onset of debilitating symptoms, improve quality of life, and prolong survival. The complexity of treating elderly and frail patients requires a patient-centred approach to personalise treatment. The main challenge is to optimise the balance between local control of disease, patient preferences, and the burden of treatment. A comprehensive geriatric assessment is a crucial element within the multidisciplinary dialogue. Since limited knowledge is available on the optimal non-operative treatment strategy, these patients should be treated by dedicated multidisciplinary rectal cancer experts with special interest in the elderly and frail. The aim of this narrative review was to discuss a multidisciplinary patient-centred treatment approach and provide a practical suggestion of a successfully implemented clinical care pathway.

MRI tumour regression grade in locally recurrent rectal cancer

BACKGROUND

This study aimed to investigate the agreement between magnetic resonance tumour regression grade (mrTRG) and pathological regression grade (pTRG) in patients with locally recurrent rectal cancer (LRRC). Also, the reproducibility of mrTRG was investigated.

METHODS

All patients with LRRC who underwent a resection between 2010 and 2018 after treatment with induction chemotherapy and neoadjuvant chemo(re)irradiation in whom a restaging MRI was available were retrospectively selected. All MRI scans were reassessed by two independent radiologists using the mrTRG, and the pTRG was reassessed by an independent pathologist. The interobserver agreement between the radiologists as well as between the radiologists and the pathologist was assessed with the weighted kappa test. A subanalysis was performed to evaluate the influence of the interval between imaging and surgery.

RESULTS

Out of 313 patients with LRRC treated during the study interval, 124 patients were selected. Interobserver agreement between the radiologists was fair (k = 0.28) using a two-tier grading system (mrTRG 1-2 versus mrTRG 3-5). For the lead radiologist, agreement with pTRG was moderate (k = 0.52; 95 per cent c.i. 0.36 to 0.68) when comparing good (mrTRG 1-2 and Mandard 1-2) and intermediate/poor responders (mrTRG 3-5 and Mandard 3-5), and the agreement was fair between the other abdominal radiologist and pTRG (k = 0.39; 95 per cent c.i. 0.22 to 0.56). A shorter interval (less than 7 weeks) between MRI and surgery resulted in an improved agreement (k = 0.69), compared with an interval more than 7 weeks (k = 0.340). For the lead radiologist, the positive predictive value for predicting good responders was 95 per cent (95 per cent c.i. 71 per cent to 99 per cent), whereas this was 56 per cent (95 per cent c.i. 44 per cent to 66 per cent) for the other radiologist.

CONCLUSION

This study showed that, in LRRC, the reproducibility of mrTRG among radiologists is limited and the agreement of mrTRG with pTRG is low. However, a shorter interval between MRI and surgery seems to improve this agreement and, if assessed by a dedicated radiologist, mrTRG could predict good responders.

Metabolic positron emission tomography/CT response after induction chemotherapy and chemo(re)irradiation is associated with higher negative resection margin rate in patients with locally recurrent rectal cancer

AIM

Positron emission tomography (PET)/CT can be used to monitor the metabolic changes that occur after intensified treatment with induction chemotherapy and chemo(re)irradiation for locally recurrent rectal cancer (LRRC). This study aimed to analyse the correlation between the PET/CT response and final histopathological outcomes.

METHODS

All LRRC patients who underwent induction chemotherapy prior to surgery between January 2010 and July 2020 and were monitored with pretreatment and post-treatment PET/CT were included. Visual qualitative analysis was performed, and patients were scored as having achieved a complete metabolic response (CMR), partial metabolic response (PMR) or no response (NR). The histopathological response was assessed according to the Mandard tumour regression (TRG) score and categorized as major (TRG 1-2), partial (TRG 3) or poor (TRG 4-5). The PET/CT and TRG categories were compared, and possible confounders were analysed.

RESULTS

A total of 106 patients were eligible for analysis; 24 (23%) had a CMR, 54 (51%) had a PMR and 28 (26%) had NR. PET/CT response was a significant predictor of the negative resection margin rate, achieving 96% for CMR, 69% for PMR and 50% for NR. The overall accuracy between PET score and pathological TRG was 45%, and the positive predictive value for CMR was 63%. A longer interval between post-treatment PET/CT and surgery negatively influenced the predictive value.

CONCLUSION

Metabolic PET/CT response evaluation after neoadjuvant treatment proves to be a complementary diagnostic tool to standard MRI in assessing tumour response, and may play a role for treatment planning in LRRC patients.

Improved response rate in patients with prognostically poor locally advanced rectal cancer after treatment with induction chemotherapy and chemoradiotherapy when compared with chemoradiotherapy alone: A matched case-control study

INTRODUCTION

The addition of induction chemotherapy (ICT) to neoadjuvant chemoradiotherapy (CRT) has the potential to improve outcomes in patients with locally advanced rectal cancer (LARC). However, patient selection is essential to prevent overtreatment. This study compared the complete response (CR) rate after treatment with and without ICT of LARC patients with prognostically poor characteristics.

METHODS

All LARC patients who were treated with neoadjuvant CRT, whether or not preceded by ICT, and who underwent surgery or were considered for a wait-and-see strategy between January 2016 and March 2020 in the Catharina Hospital Eindhoven, were retrospectively selected. LARC was defined as any T4 tumour, or a T2/T3 tumour with extramural venous invasion and/or tumour deposits and/or N2 lymph node status, and/or mesorectal fascia involvement (T3 tumours only). Case-control matching was performed based on the aforementioned characteristics.

RESULTS

Of 242 patients, 178 (74%) received CRT (CRT-group) and 64 patients (26%) received ICT followed by CRT (ICT-group). In the ICT-group, 3 patients (5%) did not receive the minimum of three cycles. In addition, in this selected cohort, compliance with radiotherapy was 100% in the ICT-group and 97% in the CRT-group. The CR rate was 30% in the ICT-group and 15% in the CRT-group (p = 0.011). After case-control matching, the CR rate was 28% and 9%, respectively (p = 0.013).

CONCLUSION

Treatment including ICT seemed well tolerated and resulted in a high CR rate. Hence, this treatment strategy may facilitate organ preservation and improve survival in LARC patients with prognostically poor characteristics.

Impact of a history of metastases or synchronous metastases on survival in patients with locally recurrent rectal cancer

AIM

Patients with locally recurrent rectal cancer (LRRC) frequently present with either synchronous metastases or a history of metastases. This study was conducted to evaluate whether LRRC patients without metastases have a different oncological outcome compared to patients with a history of metastases treated with curative intent or patients with potentially curable synchronous metastases.

METHOD

All consecutive LRRC patients who underwent intentionally curative surgery between 2005 and 2017 in a large tertiary hospital were retrospectively reviewed and categorized as having no metastases, a history of (curatively treated) metastases or synchronous metastases. Patients with unresectable distant metastases were excluded from the analysis.

RESULTS

Of the 349 patients who were analysed, 261 (75%) had no metastases, 42 (12%) had a history of metastases and 46 (13%) had synchronous metastases. The 3-year metastasis-free survival was 52%, 33% and 13% in patients without metastases, with a history of metastases, and with synchronous metastases, respectively (P < 0.001) A history of metastases did not influence overall survival (OS), but there was a trend towards a worse OS in patients with synchronous metastases compared with patients without synchronous metastases (hazard ratio 1.43; 95% CI 0.98-2.11).

CONCLUSION

LRRC patients with a history of curatively treated metastases have an OS comparable to that in patients without metastases and should therefore be treated with curative intent. However, LRRC patients with synchronous metastases have a poor metastasis-free survival and worse OS; in these patients, an individualized treatment approach to observe the behaviour of the disease is recommended.

Intraoperative Electron Beam Radiation Therapy (IOERT) Versus High-Dose-Rate Intraoperative Brachytherapy (HDR-IORT) in Patients With an R1 Resection for Locally Advanced or Locally Recurrent Rectal Cancer

PURPOSE

Intraoperative radiation therapy (IORT), delivered by intraoperative electron beam radiation therapy (IOERT) or high-dose-rate intraoperative brachytherapy (HDR-IORT), may reduce the local recurrence rate in patients with locally advanced and locally recurrent rectal cancer (LARC and LRRC, respectively). The aim of this study was to compare the oncological outcomes between both IORT modalities in patients with LARC or LRRC who underwent a microscopic irradical (R1) resection.

METHODS

All consecutive patients who received IORT because of an R1 resection of LARC or LRRC between 2000 and 2016 in two tertiary referral centers were included. In LARC, a resection margin of ≤2 mm was considered R1. A resection margin of 0 mm was considered R1 in LRRC.

RESULTS

In total, 215 patients with LARC were included, of whom 151 (70%) received IOERT and 64 (30%) received HDR-IORT; in addition, 158 patients with LRRC were included, of whom 112 (71%) received IOERT and 46 (29%) received HDR-IORT. After multivariable analyses, the overall survival was not significantly different between the two IORT modalities. The local recurrence-free survival was significantly longer in patients treated with HDR-IORT, both in LARC (hazard ratio [HR], 0.496; 95% CI, 0.253-0.973; P = .041) and LRRC (HR, 0.567; 95% CI, 0.349-0.920; P = .021). In patients with LARC, major postoperative complications were similar for both IORT modalities (IOERT, 30%; HDR-IORT, 27%), whereas in patients with LRRC, the incidence of major postoperative complications was higher after HDR-IORT (IOERT, 26%; HDR-IORT, 46%).

CONCLUSIONS

This study showed a significantly better local recurrence-free survival in favor of HDR-IORT in patients with an R1 resection for LARC or LRRC. Optimization of the IOERT technique seems warranted.

Salvage Endoscopic Full-Thickness Resection of Colorectal Carcinoma after Radiotherapy in a Patient Not Eligible for Surgery

For early, superficial colorectal carcinoma, endoscopic resection is an accepted curative treatment with an excellent long-term prognosis. Our report is the first report describing endoscopic full-thickness resection (eFTR) of residual recto-sigmoid carcinoma after radiotherapy. Our patient with cT2N0M0 recto-sigmoid carcinoma had been treated with radiotherapy because severe comorbidity precluded surgical resection. When the residual tumor was observed endoscopically, complete remission was achieved by endoscopic full thickness resection. There were no endoscopic or radiological signs of recurrent malignancy after the two-years follow-up period. In selected cases, eFTR after radiotherapy could be a curative treatment option.

Prognostic implications of MRI-detected lateral nodal disease and extramural vascular invasion in rectal cancer

BACKGROUND

Lateral nodal disease in rectal cancer remains a subject of debate and is treated differently in the East and the West. The predictive value of lateral lymph node and MRI-detected extramural vascular invasion (mrEMVI) features on oncological outcomes was assessed in this study.

METHODS

In this retrospective cohort study, data on patients with cT3-4 rectal cancer within 8 cm from the anal verge were considered over a 5-year period (2009-2013). Lateral lymph node size, malignant features and mrEMVI features were evaluated and related to oncological outcomes.

RESULTS

In total, 192 patients were studied, of whom 30 (15·6 per cent) underwent short-course radiotherapy and 145 (75·5 per cent) received chemoradiotherapy. A lateral lymph node short-axis size of 10 mm or more was associated with a significantly higher 5-year lateral/presacral local recurrence rate of 37 per cent, compared with 7·7 per cent in nodes smaller than 10 mm (P = 0·041). Enlarged nodes did not result in a higher 5-year rate of distant metastasis (23 per cent versus 27·7 per cent in nodes smaller than 10 mm; P = 0·563). However, mrEMVI positivity was related to more metastatic disease (5-year rate 43 versus 26·3 per cent in the mrEMVI-negative group; P = 0·014), but not with increased lateral/presacral recurrence. mrEMVI occurred in 46·6 per cent of patients with nodes smaller than 10 mm, compared with 29 per cent in patients with nodes of 10 mm or larger (P = 0·267).

CONCLUSION

Although lateral nodal disease is more a local problem, mrEMVI mainly predicts distant recurrence. The results of this study showed an unacceptably high local recurrence rate in patients with a short axis of 10 mm or more, despite neoadjuvant (chemo)radiotherapy.

Preliminary results of a cohort study of induction chemotherapy-based treatment for locally recurrent rectal cancer

BACKGROUND

A significant number of patients treated for locally recurrent rectal cancer have local or systemic failure, especially after incomplete surgical resection. Neoadjuvant treatment regimens in patients who have already undergone preoperative (chemo)radiotherapy for the primary tumour are limited. The objective of the present study was to evaluate the influence of a neoadjuvant regimen incorporating induction chemotherapy (ICT) in patients with locally recurrent rectal cancer who had preoperative (chemo)radiotherapy for the primary cancer or an earlier local recurrence.

METHODS

Patients were treated with a sequential neoadjuvant regimen including three or four cycles of 5-fluorouracil and oxaliplatin-containing chemotherapy. When no progressive disease was found at evaluation, neoadjuvant treatment was continued with chemoradiation therapy (CRRT) using 30 Gy with concomitant capecitabine. If there was a response to ICT, the patient was advised to continue with systemic chemotherapy after CRRT as consolidation chemotherapy while waiting for resection. These patients were compared with patients who received CRRT alone in the same time interval.

RESULTS

Of 58 patients who had ICT, 32 (55 per cent) had surgery with clear resection margins, of whom ten (17 per cent) exhibited a pathological complete response (pCR). The remaining 26 patients had 23 R1 and three R2 resections. In 71 patients who received CRRT, a similar rate of R0 (35 patients) and R1 (36) resection was found (P = 0·506), but only three patients (4 per cent) had a pCR (P = 0·015).

CONCLUSION

The incorporation of ICT in neoadjuvant regimens for locally recurrent rectal cancer is a promising strategy.

Serum screening with Down's syndrome markers to predict pre-eclampsia and small for gestational age: systematic review and meta-analysis

Background

Reliable antenatal identification of pre-eclampsia and small for gestational age is crucial to judicious allocation of monitoring resources and use of preventative treatment with the prospect of improving maternal/perinatal outcome. The purpose of this systematic review was to determine the accuracy of five serum analytes used in Down's serum screening for prediction of pre-eclampsia and/or small for gestational age.

Methods

The data sources included Medline, Embase, Cochrane library, Medion (inception to February 2007), hand searching of relevant journals, reference list checking of included articles, contact with experts. Two reviewers independently selected the articles in which the accuracy of an analyte used in Downs's serum screening before the 25^th gestational week was associated with the occurrence of pre-eclampsia and/or small for gestational age without language restrictions. Two authors independently extracted data on study characteristics, quality and results.

Results

Five serum screening markers were evaluated. 44 studies, testing 169,637 pregnant women (4376 pre-eclampsia cases) and 86 studies, testing 382,005 women (20,339 fetal growth restriction cases) met the selection criteria. The results showed low predictive accuracy overall. For pre-eclampsia the best predictor was inhibin A>2.79MoM positive likelihood ratio 19.52 (8.33,45.79) and negative likelihood ratio 0.30 (0.13,0.68) (single study). For small for gestational age it was AFP>2.0MoM to predict birth weight < 10^th centile with birth < 37 weeks positive likelihood ratio 27.96 (8.02,97.48) and negative likelihood ratio 0.78 (0.55,1.11) (single study). A potential clinical application using aspirin as a treatment is given as an example.

There were methodological and reporting limitations in the included studies thus studies were heterogeneous giving pooled results with wide confidence intervals.

Conclusion

Down's serum screening analytes have low predictive accuracy for pre-eclampsia and small for gestational age. They may be a useful means of risk assessment or of use in prediction when combined with other tests.

Accuracy of mean arterial pressure and blood pressure measurements in predicting pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the accuracy of using systolic and diastolic blood pressure, mean arterial pressure, and increase of blood pressure to predict pre-eclampsia.

DESIGN

Systematic review with meta-analysis of data on test accuracy.

DATA SOURCES

Medline, Embase, Cochrane Library, Medion, checking reference lists of included articles and reviews, contact with authors. Review methods Without language restrictions, two reviewers independently selected the articles in which the accuracy of blood pressure measurement during pregnancy was evaluated to predict pre-eclampsia. Data were extracted on study characteristics, quality, and results to construct 2x2 tables. Summary receiver operating characteristic curves and likelihood ratios were generated for the various levels and their thresholds.

RESULTS

34 studies, testing 60 599 women (3341 cases of pre-eclampsia), were included. In women at low risk for pre-eclampsia, the areas under the summary receiver operating characteristic curves for blood pressure measurement in the second trimester were 0.68 (95% confidence interval 0.64 to 0.72) for systolic blood pressure, 0.66 (0.59 to 0.72) for diastolic blood pressure, and 0.76 (0.70 to 0.82) for mean arterial pressure. Findings for the first trimester showed a similar pattern. Second trimester mean arterial pressure of 90 mm Hg or more showed a positive likelihood ratio of 3.5 (95% confidence interval 2.0 to 5.0) and a negative likelihood ratio of 0.46 (0.16 to 0.75). In women deemed to be at high risk, a diastolic blood pressure of 75 mm Hg or more at 13 to 20 weeks' gestation best predicted pre-eclampsia: positive likelihood ratio 2.8 (1.8 to 3.6), negative likelihood ratio 0.39 (0.18 to 0.71). Additional subgroup analyses did not show improved predictive accuracy.

CONCLUSION

When blood pressure is measured in the first or second trimester of pregnancy, the mean arterial pressure is a better predictor for pre-eclampsia than systolic blood pressure, diastolic blood pressure, or an increase of blood pressure.

Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis

BACKGROUND

Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters.

METHODS

We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios.

RESULTS

We identified 74 studies of pre-eclampsia (total 79,547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients.

INTERPRETATION

Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.

Methods of prediction and prevention of pre-eclampsia: systematic reviews of accuracy and effectiveness literature with economic modelling

OBJECTIVES

To investigate the accuracy of predictive tests for pre-eclampsia and the effectiveness of preventative interventions for pre-eclampsia. Also to assess the cost-effectiveness of strategies (test-intervention combinations) to predict and prevent pre-eclampsia.

DATA SOURCES

Major electronic databases were searched to January 2005 at least.

REVIEW METHODS

Systematic reviews were carried out for test accuracy and effectiveness. Quality assessment was carried out using standard tools. For test accuracy, meta-analyses used a bivariate approach. Effectiveness reviews were conducted under the auspices of the Cochrane Pregnancy and Childbirth Group and used standard Cochrane review methods. The economic evaluation was from an NHS perspective and used a decision tree model.

RESULTS

For the 27 tests reviewed, the quality of included studies was generally poor. Some tests appeared to have high specificity, but at the expense of compromised sensitivity. Tests that reached specificities above 90% were body mass index greater than 34, alpha-foetoprotein and uterine artery Doppler (bilateral notching). The only Doppler test with a sensitivity of over 60% was resistance index and combinations of indices. A few tests not commonly found in routine practice, such as kallikreinuria and SDS-PAGE proteinuria, seemed to offer the promise of high sensitivity, without compromising specificity, but these would require further investigation. For the 16 effectiveness reviews, the quality of included studies was variable. The largest review was of antiplatelet agents, primarily low-dose aspirin, and included 51 trials (36,500 women). This was the only review where the intervention was shown to prevent both pre-eclampsia and its consequences for the baby. Calcium supplementation also reduced the risk of pre-eclampsia, but with some uncertainty about the impact on outcomes for the baby. The only other intervention associated with a reduction in RR of pre-eclampsia was rest at home, with or without a nutritional supplement, for women with normal blood pressure. However, this review included just two small trials and its results should be interpreted with caution. The cost of most of the tests was modest, ranging from 5 pounds for blood tests such as serum uric acid to approximately 20 pounds for Doppler tests. Similarly, the cost of most interventions was also modest. In contrast, the best estimate of additional average cost associated with an average case of pre-eclampsia was high at approximately 9000 pounds. The results of the modelling revealed that prior testing with the test accuracy sensitivities and specificities identified appeared to offer little as a way of improving cost-effectiveness. Based on the evidence reviewed, none of the tests appeared sufficiently accurate to be clinically useful and the results of the model favoured no-test/treat-all strategies. Rest at home without any initial testing appeared to be the most cost-effective 'test-treatment' combination. Calcium supplementation to all women, without any initial testing, appeared to be the second most cost-effective. The economic model provided little support that any form of Doppler test has sufficiently high sensitivity and specificity to be cost-effective for the early identification of pre-eclampsia. It also suggested that the pattern of cost-effectiveness was no different in high-risk mothers than the low-risk mothers considered in the base case.

CONCLUSIONS

The tests evaluated are not sufficiently accurate, in our opinion, to suggest their routine use in clinical practice. Calcium and antiplatelet agents, primarily low-dose aspirin, were the interventions shown to prevent pre-eclampsia. The most cost-effective approach to reducing pre-eclampsia is likely to be the provision of an effective, affordable and safe intervention applied to all mothers without prior testing to assess levels of risk. It is probably premature to suggest the implementation of a treat-all intervention strategy at present, however the feasibility and acceptability of this to women could be explored. Rigorous evaluation is needed of tests with modest cost whose initial assessments suggest that they may have high levels of both sensitivity and specificity. Similarly, there is a need for high-quality, adequately powered randomised controlled trials to investigate whether interventions such as advice to rest are indeed effective in reducing pre-eclampsia. In future, an economic model should be developed that considers not just pre-eclampsia, but other related outcomes, particularly those relevant to the infant such as perinatal death, preterm birth and small for gestational age. Such a modelling project should make provision for primary data collection on the safety of interventions and their associated costs.

Systematic review: Accuracy of body mass index in predicting pre-eclampsia: bivariate meta-analysis

OBJECTIVE

The objective of this study was to determine the accuracy of body mass index (BMI) (pre-pregnancy or at booking) in predicting pre-eclampsia and to explore its potential for clinical application.

DESIGN

Systematic review and bivariate meta-analysis.

SETTING

Medline, Embase, Cochrane Library, MEDION, manual searching of reference lists of review articles and eligible primary articles, and contact with experts.

POPULATION

Pregnant women at any level of risk in any healthcare setting.

METHODS

Reviewers independently selected studies and extracted data on study characteristics, quality, and accuracy. No language restrictions.

MAIN OUTCOME MEASURES

Pooled sensitivities and specificities (95% CI), a summary receiver operating characteristic curve, and corresponding likelihood ratios (LRs). The potential value of BMI was assessed by combining its predictive capacity for different prevalences of pre-eclampsia and the therapeutic effectiveness (relative risk 0.90) of aspirin.

RESULTS

A total of 36 studies, testing 1,699,073 pregnant women (60,584 women with pre-eclampsia), met the selection criteria. The median incidence of pre-eclampsia was 3.9% (interquartile range 1.4-6.8). The area under the curve was 0.64 with 93% of heterogeneity explained by threshold differences. Pooled estimates (95% CI) for all studies with a BMI > or = 25 were 47% (33-61) for sensitivity and 73% (64-83) for specificity; and 21% (12-31) and 92% (89-95) for a BMI > or = 35. Corresponding LRs (95% CI) were 1.7 (0.3-11.9) for BMI > or = 25 and 0.73 (0.22-2.45) for BMI < 25, and 2.7 (1.0-7.3) for BMI > or = 35 and 0.86 (0.68-1.07) for BMI < 35. The number needed to treat with aspirin to prevent one case of pre-eclampsia ranges from 714 (no testing, low-risk women) to 37 (BMI > or = 35, high-risk women).

CONCLUSIONS

BMI appears to be a fairly weak predictor for pre-eclampsia. Although BMI is virtually free of cost, noninvasive, and ubiquitously available, its usefulness as a stand-alone test for risk stratification must await formal cost-utility analysis. The findings of this review may serve as input for such analyses.

Accuracy of fibronectin tests for the prediction of pre-eclampsia: a systematic review

The purpose of this study was to review systematically all studies that assessed the accuracy of maternal plasma fibronectin as a serum marker for early prediction of pre-eclampsia. We therefore assessed studies that reported on fibronectin as serum marker for pre-eclampsia before the 25th gestational week. For the selected studies, sensitivity and specificity were calculated and plotted in ROC-space. We included 12 studies, of which only 5 studies reported sufficient data to calculate accuracy estimates, such as sensitivity and specificity. These five studies reported on 573 pregnant women of whom 109 developed pre-eclampsia. At a sensitivity of at least 50%, specificities ranged between 72 and 96% for cellular fibronectin. For total fibronectin, these numbers were 42-94%. Fibronectin seems to be a promising marker for the prediction of pre-eclampsia, however, further studies are needed to determine whether the accuracy of this test is sufficient to be clinically relevant.

Prediction of pre-eclampsia: a protocol for systematic reviews of test accuracy

BACKGROUND

Pre-eclampsia, a syndrome of hypertension and proteinuria, is a major cause of maternal and perinatal morbidity and mortality. Accurate prediction of pre-eclampsia is important, since high risk women could benefit from intensive monitoring and preventive treatment. However, decision making is currently hampered due to lack of precise and up to date comprehensive evidence summaries on estimates of risk of developing pre-eclampsia.

METHODS/DESIGN

A series of systematic reviews and meta-analyses will be undertaken to determine, among women in early pregnancy, the accuracy of various tests (history, examinations and investigations) for predicting pre-eclampsia. We will search Medline, Embase, Cochrane Library, MEDION, citation lists of review articles and eligible primary articles and will contact experts in the field. Reviewers working independently will select studies, extract data, and assess study validity according to established criteria. Language restrictions will not be applied. Bivariate meta-analysis of sensitivity and specificity will be considered for tests whose studies allow generation of 2 x 2 tables.

DISCUSSION

The results of the test accuracy reviews will be integrated with results of effectiveness reviews of preventive interventions to assess the impact of test-intervention combinations for prevention of pre-eclampsia.

Accuracy of serum uric acid determination in predicting pre-eclampsia: A systematic review3-33

BACKGROUND

Pre-eclampsia is a leading cause of maternal and perinatal mortality and morbidity. Early prediction of pre-eclampsia may be used to target high-risk women for effective preventative treatments. Hyperuricemia is associated with pre-eclampsia and it has been tested in early pregnancy for its ability to predict the later onset of the disease.

OBJECTIVE

To systematically review the accuracy of determining serum uric acid before the 25th gestational week in predicting pre-eclampsia.

METHODS

We searched Medline, Embase, Cochrane Library, Medion, bibliographies of review articles and eligible primary studies, and contacted experts in the field. Language restrictions were not applied. Reviewers working independently selected studies, extracted data and assessed validity according to eight criteria. Sensitivities and specificities were plotted in a Receiver Operating Characteristic plot.

RESULTS

We identified five primary articles, with a total of 572 women, including 44 who developed pre-eclampsia. Study populations differed clinically, with incidences ranging from 3.4% to 40.1%. Sensitivity ranged from 0.0% to 55.6% and specificity ranged from 76.9% to 94.9%. Clinical heterogeneity and poor reporting precluded sensible pooling of data. In particular, consecutive entry of eligible women, blind assessment of the reference standard, and treatment to prevent pre-eclampsia were poorly reported.

CONCLUSION

Contrary to previous reviews, we conclude that there is currently insufficient evidence to draw firm conclusions about the accuracy of serum uric acid determination in predicting pre-eclampsia.