Diagnostic accuracy of laparoscopy following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

Added value of digital FDG-PET/CT in disease staging and restaging in patients with resectable or borderline resectable pancreatic cancer

BACKGROUND

We studied the added value of digital FDG-PET/CT in disease staging and restaging compared to the standard work-up with contrast enhanced CT (ceCT) and CA19-9 in patients with resectable or borderline resectable pancreatic cancer who received neo-adjuvant therapy. Primary endpoints were tumor response compared to ceCT and CA19.9 as well as the ability to detect distant metastatic disease.

METHODS

35 patients were included in this dual-center prospective study. FDG-PET using digital photon counting technology combined with CT scans were acquired before (T₁) and after neo-adjuvant therapy (T₂). Patients were staged and restaged based on standard protocol with ceCT and CA 19.9, while all PET/CT scans were stored securely and not included in clinical decision making. After the pancreatic resection, an expert team retrospectively assessed the CT tumor diameter, CA19-9, tumor FDG-uptake, and appearance of metastatic disease of all patients for both time points.

RESULTS

CA19-9 levels, CT tumor diameter, and tumor FDG-uptake on PET significantly decreased from T₁ to T₂ (p = 0.017, p = 0.001, and p < 0.0001). The change in FDG-uptake values showed a strong positive correlation with the change in CT tumor diameter and change in CA19-9 (R = 0.75 and R = 0.73, respectively). In addition, small-volume liver lesions were detected on digital PET/CT in 5/35 patients (14%), 4 of which were pathology confirmed at laparotomy. Only one of these five cases was detected on baseline staging ceCT (3%).

CONCLUSION

We found that adding digital PET/CT strengthens restaging after neo-adjuvant therapy based on the observed strong correlation with ceCT tumor diameter and Ca19.9. Also, digital PET/CT was found to detect occult metastatic disease not visualized on ceCT, that would have resulted in altered disease staging and therapeutic strategy in a substantial proportion of patients.

LDL receptor-peptide conjugate as in vivo tool for specific targeting of pancreatic ductal adenocarcinoma

Despite clinical advances in diagnosis and treatment, pancreatic ductal adenocarcinoma (PDAC) remains the third leading cause of cancer death, and is still associated with poor prognosis and dismal survival rates. Identifying novel PDAC-targeted tools to tackle these unmet clinical needs is thus an urgent requirement. Here we use a peptide conjugate that specifically targets PDAC through low-density lipoprotein receptor (LDLR). We demonstrate by using near-infrared fluorescence imaging the potential of this conjugate to specifically detect and discriminate primary PDAC from healthy organs including pancreas and from benign mass-forming chronic pancreatitis, as well as detect metastatic pancreatic cancer cells in healthy liver. This work paves the way towards clinical applications in which safe LDLR-targeting peptide conjugate promotes tumor-specific delivery of imaging and/or therapeutic agents, thereby leading to substantial improvements of the PDAC patient’s outcome.

Acier et al. investigated a peptide cargo system, the Fc(A680)-VH4127, that targets PDAC through the LDLR cell-surface receptor. The Fc(A680)-VH4127 was found to specifically target spontaneous pancreatic tumors in KICmice, as well as metastatic pancreatic tumors in liver.

Curing pancreatic cancer

The distinct biology of pancreatic cancer with aggressive and early invasive tumor cells, a tumor promoting microenvironment, late diagnosis, and high therapy resistance poses major challenges on clinicians, researchers, and patients. In current clinical practice, a curative approach for pancreatic cancer can only be offered to a minority of patients and even for those patients, the long-term outcome is grim. This bitter combination will eventually let pancreatic cancer rise to the second leading cause of cancer-related mortalities. With surgery being the only curative option, complete tumor resection still remains the center of pancreatic cancer treatment. In recent years, new developments in neoadjuvant and adjuvant treatment have emerged. Together with improved perioperative care including complication management, an increasing number of patients have become eligible for tumor resection. Basic research aims to further increase these numbers by new methods of early detection, better tumor modelling and personalized treatment options. This review aims to summarize the current knowledge on clinical and biologic features, surgical and non-surgical treatment options, and the improved collaboration of clinicians and basic researchers in pancreatic cancer that will hopefully result in more successful ways of curing pancreatic cancer.

Predicting positive peritoneal cytology in pancreatic cancer

INTRODUCTION

Positive cytology from peritoneal washings obtained prior to potential resection of pancreatic cancer is associated with grim prognosis, equivalent to M1 disease. We examine our experience with pancreatic cancer patients who underwent pre-resection lavage in an attempt to predict who would have malignant cells on peritoneal cytology.

METHODS

We conducted a retrospective review of patients undergoing pancreatectomy for pancreatic adenocarcinoma at a tertiary care institution from 1995 to 2019 and had pre-resection lavage performed. Demographic and clinicopathologic data were collected. Logistic regression models were used to identify predictors of positive cytology.

RESULTS

Three hundred ninety-nine patients underwent pancreatic resection and had lavage performed. Forty-three (10.8%) had positive peritoneal cytology. Those with positive cytology had higher median Ca19-9 value than those with negative cytology at diagnosis (368.5 vs 200 U/mL, p = 0.007) and after neoadjuvant therapy (100.3 vs 43 U/mL, p = 0.013). After controlling for preoperative therapy received, an initial Ca19-9 greater than 1220 U/mL (OR 2.72, 95% CI 1.07-6.89, p = 0.035), locally advanced disease (OR 4.86, 95% CI 1.31-18.09, p = 0.018), and BMI ≥ 25 kg/m² (OR 2.67, 95% CI 1.04-6.97, p = 0.042) were associated with positive cytology in multivariate logistic regression model. The associated ROC curve had an AUC of 0.7507, suggesting adequate discrimination of those with positive peritoneal cytology.

CONCLUSION

Diagnostic laparoscopy remains an important adjunct to the workup, diagnosis, and staging of pancreatic adenocarcinoma. Patients with locally advanced disease, significantly elevated serum Ca19-9 at diagnosis, and BMI ≥ 25 kg/m² may be at higher risk for positive peritoneal cytology, regardless of whether neoadjuvant therapy is administered.

Imaging and Management of Pancreatic Cancer

Pancreatic cancer is an aggressive disease with rising incidence and high mortality despite advances in imaging and therapeutic options. Surgical resection is currently the only curative treatment, with expanding roles for adjuvant and neoadjuvant chemoradiation. Accurate detection, staging, and post-treatment monitoring of pancreatic cancer are critical to improving survival and imaging plays a central role in the multidisciplinary approach to this disease. This article will provide a broad overview of the imaging and management of pancreatic cancer with a focus on diagnosis and staging, operative and nonoperative treatments, and post-therapeutic appearances after surgery and chemoradiation therapy.

Surgical exploration without resection in pancreatic and periampullary tumors: Report from a national database

Background and objective:

Pancreatic and periampullary cancers are sometimes found to have a too advanced disease during surgery to allow resection. The aim was to describe characteristics, treatment, outcome, and time trends for patients that were planned for pancreatic surgery but found unresectable during surgery.

Methods:

Data from the Swedish National Pancreatic and Periampullary Cancer Registry were used. All patients registered between January 2010 and August 2018 were included. The patient cohort was divided in two halves based on year of diagnosis.

Results:

In total, 12,377 patients were included in the registry and finally 4568 patients were scheduled for surgery. During surgical exploration, 3879 (84.9%) patients underwent pancreatic resection, 658 (14.4%) patients were found unresectable, and 31 (0.7%) had no pancreatic resection due to other reasons (e.g. benign lesion, comorbidity). More patients underwent surgical exploration and resection during the second time period, but exploration without resection was unchanged (15.7% vs 13.7%; p = 0.062). Survival rates were lower among the unresectable patients with pancreatic and periampullary tumors compared to the resectable patients, including 30-day mortality (n = 17 (3.5%) vs n = 39 (1.6%), p = 0.004) and 90-day mortality (n = 72 (15.0%) vs n = 70 (2.8%), p < 0.001). Palliative surgery became less common during the second half of the time period (p < 0.001).

Conclusions:

Unresectability is associated with an unfavorable prognosis. The frequency did not decrease during the study period, but palliative surgical procedures became less common.

White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology's disease-focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy with a poor 5-year survival rate. Accurate staging of PDAC is an important initial step in the development of a stage-specific treatment plan. Different staging systems/consensus statements convened by different societies and academic practices are currently used. The most recent version of the American Joint Committee on Cancer (AJCC) tumor/node/metastases (TNM) staging system for PDAC has shifted its focus from guiding management to assessing prognosis. In order to preoperatively define the resectability of PDAC and to guide management, additional classification systems have been developed. The National Comprehensive Cancer Network (NCCN) guidelines, one of the most commonly used systems, provide recommendations on the management and the determination of resectability for PDAC. The NCCN divides PDAC into three categories of resectability based on tumor-vessel relationship: 'resectable,' 'borderline resectable,' and 'unresectable'. Among these, the borderline disease category is of special interest given its evolution over time and the resulting variations in the definition and the associated recommendations for management between different societies. It is important to be familiar with the evolving criteria, and treatment and follow-up recommendations for PDAC. In this article, the most current AJCC staging (8th edition), NCCN guidelines (version 2.2019-April 9, 2019), and challenges and controversies in borderline resectable PDAC are reviewed.

Role of Staging Laparoscopy in Patients Undergoing Pancreaticoduodenectomy

Background Pancreatic cancer patients undergoing curative resection need staging laparoscopy for detecting metastatic disease not picked up on standard radiological scans. Identifying these patients can help to prevent unnecessary laparotomies and early induction of palliative therapies. The aim of our study was to determine the effect of staging laparoscopy on resectable pancreatic or periampullary tumors at our hospital. Methods Patients recommended pancreaticoduodenectomy between September 2014 and June 2018 were included in this study. Any significant finding and its impact on management was recorded. Results A total of 120 patients underwent staging laparoscopy. Fifteen patients had suspicious lesions and one patient had cirrhotic liver on staging laparoscopy. Out of these 15 patients nine patients had liver lesions, three patients with peritoneal nodules and three patients having both liver and peritoneal lesions. Among patients with liver lesions, four patients were found to have metastatic deposits. All of the remaining lesions were benign. Plan of curative resection was changed in five patients. Three patients who were planned for pancreaticoduodenectomy cancelled because of hepatic metastasis. One patient with hepatic metastasis showing neuroendocrine tumor considered for resection. One patient with resectable disease had cirrhotic liver on laparoscopy, so not medically fit for this major surgery. Conclusion In patients planned for pancreaticoduodenectomy, staging laparoscopy is an important step to detect metastatic disease involving peritoneum or viscera. It is very helpful in determining the stage of disease and further management plan.

CA 19-9 predicts resectability of pancreatic cancer even in jaundiced patients

BACKGROUND

Surgical resection remains the only curative option for pancreatic adenocarcinoma. Despite recent improvements in medical imaging, unresectability is still often discovered at the time of surgery. It is essential to identify unresectable patients preoperatively to avoid unnecessary surgery. High serum CA 19-9 levels have been suggested as a marker of unresectability but considered inaccurate in patients with hyperbilirubinemia.

AIM OF THE STUDY

To evaluate CA 19-9 serum levels as a predictor of unresectability of pancreatic adenocarcinomas with a special focus on jaundiced patients.

METHODS

All patients presenting with histologically-confirmed pancreatic adenocarcinoma and having serum CA 19-9 levels available prior to any treatment were included in this retrospective study. The relationship between serum concentrations of CA 19-9 and resectability was studied by regression analysis and theROC curves obtained. A cut-off value of CA 19-9 was calculated. In jaundiced patients, a CA 19-9 adjusted for bilirubinemia was also evaluated.

RESULTS

Of the 171 patients included, 49 (29%) were deemed resectable and 122 (71%) unresectable. Altogether, 93 patients (54%) had jaundice. The area under the ROC curve for CA 19-9 as a predictor of resectability was 0.886 (95%CI:[0.832-0.932]); in jaundiced patients it was 0.880 (95% CI [0.798-0.934]. A cut-off in CA 19-9 at 178 UI/mlyielded 85% sensitivity, 81% specificity and 91% positive predictive value for resectability. There was no correlation between the levels of bilirubin and CA 19-9 (r = 0.149).

CONCLUSION

Serum CA 19-9 is a good predictive marker of unresectability of pancreatic adenocarcinoma, even in jaundiced patients. CA 19-9 levels over 178 UI/ml strongly suggest unresectable disease.

Neoadjuvant therapy for resectable pancreatic cancer

The use of neoadjuvant therapies has played a major role for borderline resectable and locally advanced pancreatic cancers (PCs). For this group of patients, preoperative chemotherapy or chemoradiation has increased the likelihood of surgery with negative resection margins and overall survival. On the other hand, for patients with resectable PC, the main rationale for neoadjuvant therapy is that the overall survival with current strategies is unsatisfactory. There is a consensus that we need new treatments to improve the overall survival and quality of life of patients with PC. However, without strong scientific evidence supporting the theoretical advantages of neoadjuvant therapies, these potential benefits might turn out not to be worth the risk of tumors progression while waiting for surgery. The focus of this paper is to provide the readers an overview of the most recent evidence on this subject.

Diagnostic Laparoscopy Prior to Neoadjuvant Therapy in Pancreatic Cancer Is High Yield: an Analysis of Outcomes and Costs

BACKGROUND

There is currently no standardized regimen for management of borderline resectable pancreatic cancer (BRPC), and treatment includes varying sequences of surgery, chemotherapy, and/or radiation. This study examines the diagnostic yield and cost of performing staging diagnostic laparoscopy (SDL) prior to neoadjuvant therapy (NAT) in BRPC.

METHODS

Sequential patients treated for BRPC between January 2010 and October 2013 were included. SDL was adopted in a staged fashion due to surgeon preference, and included biopsy of visible lesions and washings for cytology. Cost ratios (CRs) were calculated to compare the direct cost of the SDL versus no-SDL groups and to compare patients with positive versus negative SDL.

RESULTS

Of 116 patients evaluated for BRPC, 75 patients underwent SDL and 19 (25%) revealed occult metastatic disease. Sixteen patients had a positive biopsy and three had positive cytology alone. There was no difference in overall treatment cost (CR 0.95, 95% CI 0.62-1.37), oncologic treatment (CR 0.66, 95% CI 0.32-1.23), or remaining surgical treatment (CR 1.14, 95% CI 0.77-1.71) for patients who underwent SDL compared to those who did not. Patients with a positive SDL incurred lower overall cost compared to those with a negative SDL (CR 0.23, 95% CI 0.16-0.32) due to lack of further surgery or radiation, and less intensive chemotherapy regimens.

CONCLUSIONS

SDL prior to NAT is a useful adjunct to CT to diagnose occult metastatic disease in BRPC.

Contrast-enhanced CT in determining resectability in patients with pancreatic carcinoma: a meta-analysis of the positive predictive values of CT

OBJECTIVE

To obtain a summary positive predictive value (sPPV) of contrast-enhanced CT in determining resectability.

METHODS

The MEDLINE and EMBASE databases from JAN2005 to DEC2015 were searched and checked for inclusion criteria. Data on study design, patient characteristics, imaging techniques, image evaluation, reference standard, time interval between CT and reference standard, and data on resectability/unresectablity were extracted by two reviewers. We used a fixed-effects or random-effects approach to obtain sPPV for resectability. Several subgroups were defined: 1) bolus-triggering versus fixed-timing; 2) pancreatic and portal phases versus portal phase alone; 3) all criteria (liver metastases/lymphnode involvement/local advanced/vascular invasion) versus only vascular invasion as criteria for unresectability.

RESULTS

Twenty-nine articles were included (2171 patients). Most studies were performed in multicentre settings, initiated by the department of radiology and retrospectively performed. The I2-value was 68%, indicating heterogeneity of data. The sPPV was 81% (95%CI: 75-86%). False positives were mostly liver, peritoneal, or lymphnode metastases. Bolus-triggering had a slightly higher sPPV compared to fixed-timing, 87% (95%CI: 81-91%) versus 78% (95%CI: 66-86%) (p = 0.077). No differences were observed in other subgroups.

CONCLUSIONS

This meta-analysis showed a sPPV of 81% for predicting resectability by CT, meaning that 19% of patients falsely undergo surgical exploration.

KEY POINTS

• Predicting resectability of pancreatic cancer by CT is 81% (95%CI: 75-86%). • The percentage of patients falsely undergoing surgical exploration is 19%. • The false positives are liver metastases, peritoneal metastases, or lymph node metastases.

Diagnostic accuracy of laparoscopy following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

BACKGROUND

Surgical resection is the only potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Laparoscopy can detect metastases not visualised on CT scanning, enabling better assessment of the spread of cancer (staging of cancer). This is an update to a previous Cochrane Review published in 2013 evaluating the role of diagnostic laparoscopy in assessing the resectability with curative intent in people with pancreatic and periampullary cancer.

OBJECTIVES

To determine the diagnostic accuracy of diagnostic laparoscopy performed as an add-on test to CT scanning in the assessment of curative resectability in pancreatic and periampullary cancer.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, EMBASE via OvidSP (from inception to 15 May 2016), and Science Citation Index Expanded (from 1980 to 15 May 2016).

SELECTION CRITERIA

We included diagnostic accuracy studies of diagnostic laparoscopy in people with potentially resectable pancreatic and periampullary cancer on CT scan, where confirmation of liver or peritoneal involvement was by histopathological examination of suspicious (liver or peritoneal) lesions obtained at diagnostic laparoscopy or laparotomy. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment using the QUADAS-2 tool. The specificity of diagnostic laparoscopy in all studies was 1 because there were no false positives since laparoscopy and the reference standard are one and the same if histological examination after diagnostic laparoscopy is positive. The sensitivities were therefore meta-analysed using a univariate random-effects logistic regression model. The probability of unresectability in people who had a negative laparoscopy (post-test probability for people with a negative test result) was calculated using the median probability of unresectability (pre-test probability) from the included studies, and the negative likelihood ratio derived from the model (specificity of 1 assumed). The difference between the pre-test and post-test probabilities gave the overall added value of diagnostic laparoscopy compared to the standard practice of CT scan staging alone.

MAIN RESULTS

We included 16 studies with a total of 1146 participants in the meta-analysis. Only one study including 52 participants had a low risk of bias and low applicability concern in the patient selection domain. The median pre-test probability of unresectable disease after CT scanning across studies was 41.4% (that is 41 out of 100 participants who had resectable cancer after CT scan were found to have unresectable disease on laparotomy). The summary sensitivity of diagnostic laparoscopy was 64.4% (95% confidence interval (CI) 50.1% to 76.6%). Assuming a pre-test probability of 41.4%, the post-test probability of unresectable disease for participants with a negative test result was 0.20 (95% CI 0.15 to 0.27). This indicates that if a person is said to have resectable disease after diagnostic laparoscopy and CT scan, there is a 20% probability that their cancer will be unresectable compared to a 41% probability for those receiving CT alone.A subgroup analysis of people with pancreatic cancer gave a summary sensitivity of 67.9% (95% CI 41.1% to 86.5%). The post-test probability of unresectable disease after being considered resectable on both CT and diagnostic laparoscopy was 18% compared to 40.0% for those receiving CT alone.

AUTHORS' CONCLUSIONS

Diagnostic laparoscopy may decrease the rate of unnecessary laparotomy in people with pancreatic and periampullary cancer found to have resectable disease on CT scan. On average, using diagnostic laparoscopy with biopsy and histopathological confirmation of suspicious lesions prior to laparotomy would avoid 21 unnecessary laparotomies in 100 people in whom resection of cancer with curative intent is planned.

Advances in the Surgical Management of Resectable and Borderline Resectable Pancreas Cancer

Successful surgical resection offers the only chance for cure in patients with pancreatic cancer. However, pancreatic resection is feasible in less than 20% of the patients. In this review, the current state of surgical management of pancreatic cancer is discussed. The definition of resectability based on cross-sectional imaging and the technical aspects of surgery, including vascular resection and/or reconstruction, management of aberrant vascular anatomy and extent of lymphadenectomy, are appraised. Furthermore, common pancreatic resection-specific postoperative complications and their management are reviewed.

Preoperative radiochemotherapy versus immediate surgery for resectable and borderline resectable pancreatic cancer (PREOPANC trial): study protocol for a multicentre randomized controlled trial

Background

Pancreatic cancer is the fourth largest cause of cancer death in the United States and Europe with over 100,000 deaths per year in Europe alone. The overall 5-year survival ranges from 2–7 % and has hardly improved over the last two decades. Approximately 15 % of all patients have resectable disease at diagnosis, and of those, only a subgroup has a resectable tumour at surgical exploration. Data from cohort studies have suggested that outcome can be improved by preoperative radiochemotherapy, but data from well-designed randomized studies are lacking. Our PREOPANC phase III trial aims to test the hypothesis that median overall survival of patients with resectable or borderline resectable pancreatic cancer can be improved with preoperative radiochemotherapy.

Methods/design

The PREOPANC trial is a randomized, controlled, multicentric superiority trial, initiated by the Dutch Pancreatic Cancer Group. Patients with (borderline) resectable pancreatic cancer are randomized to A: direct explorative laparotomy or B: after negative diagnostic laparoscopy, preoperative radiochemotherapy, followed by explorative laparotomy. A hypofractionated radiation scheme of 15 fractions of 2.4 gray (Gy) is combined with a course of gemcitabine, 1,000 mg/m²/dose on days 1, 8 and 15, preceded and followed by a modified course of gemcitabine. The target volumes of radiation are delineated on a 4D CT scan, where at least 95 % of the prescribed dose of 36 Gy in 15 fractions should cover 98 % of the planning target volume. Standard adjuvant chemotherapy is administered in both treatment arms after resection (six cycles in arm A and four in arm B). In total, 244 patients will be randomized in 17 hospitals in the Netherlands. The primary endpoint is overall survival by intention to treat. Secondary endpoints are (R0) resection rate, disease-free survival, time to locoregional recurrence or distant metastases and perioperative complications. Secondary endpoints for the experimental arm are toxicity and radiologic and pathologic response.

Discussion

The PREOPANC trial is designed to investigate whether preoperative radiochemotherapy improves overall survival by means of increased (R0) resection rates in patients with resectable or borderline resectable pancreatic cancer.

Trial registration

Trial open for accrual: 3 April 2013

The Netherlands National Trial Register – NTR3709 (8 November 2012)

EU Clinical Trials Register – 2012-003181-40 (11 December 2012)

Adjuvant and neoadjuvant therapies in resectable pancreatic cancer: a systematic review of randomized controlled trials

The timing of surgery and antineoplastic therapies in patients with resectable non-metastatic pancreatic cancer is still a controversial matter of debate, with special regard to neoadjuvant approaches. Following the criteria of the PRISMA statement, a literature search was conducted looking for RCTs focusing on adjuvant and neoadjuvant therapies in resectable pancreatic cancer. The quality of the available evidence was assessed using the Cochrane Collaboration's tool for assessing risk of bias. Data extraction was carried out by two independent investigators. The search led to the identification of 2830 papers of which 14 RCTs focusing on adjuvant and neoadjuvant treatment of resectable pancreatic cancer eligible for the systematic review. Risk of bias was estimated "unclear" in 3 studies and "high" in 5 studies. Median age ranged between 53 and 66. Overall survival in the surgery-only arms ranged between 11 and 20.2 months; in the adjuvant treatment arms 12.5-29.8 months; and in the neoadjuvant setting 9.9-19.4 months. Neoadjuvant protocols should be offered only in randomized clinical trials comparing the standard of care (surgery followed by adjuvant treatments) to a neoadjuvant approach followed by surgery and adjuvant treatment.

Blood CEA levels for detecting recurrent colorectal cancer

BACKGROUND

Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation.

OBJECTIVES

To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice.

SEARCH METHODS

We conducted all searches to January 29 2014. We applied no language limits to the searches, and translated non-English manuscripts. We searched for relevant reviews in the MEDLINE, EMBASE, MEDION and DARE databases. We searched for primary studies (including conference abstracts) in the Cochrane Central Register of Controlled Trials (CENTRAL), in MEDLINE, EMBASE, and the Science Citation Index & Conference Proceedings Citation Index - Science. We identified ongoing studies by searching WHO ICTRP and the ASCO meeting library.

SELECTION CRITERIA

We included cross-sectional diagnostic test accuracy studies, cohort studies, and randomised controlled trials (RCTs) of post-resection colorectal cancer follow-up that compared CEA to a reference standard. We included studies only if we could extract 2 x 2 accuracy data. We excluded case-control studies, as the ratio of cases to controls is determined by the study design, making the data unsuitable for assessing test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors (BDN, IP) assessed the quality of all articles independently, discussing any disagreements. Where we could not reach consensus, a third author (BS) acted as moderator. We assessed methodological quality against QUADAS-2 criteria. We extracted binary diagnostic accuracy data from all included studies as 2 x 2 tables. We conducted a bivariate meta-analysis. We used the xtmelogit command in Stata to produce the pooled estimates of sensitivity and specificity and we also produced hierarchical summary ROC plots.

MAIN RESULTS

In the 52 included studies, sensitivity ranged from 41% to 97% and specificity from 52% to 100%. In the seven studies reporting the impact of applying a threshold of 2.5 µg/L, pooled sensitivity was 82% (95% confidence interval (CI) 78% to 86%) and pooled specificity 80% (95% CI 59% to 92%). In the 23 studies reporting the impact of applying a threshold of 5 µg/L, pooled sensitivity was 71% (95% CI 64% to 76%) and pooled specificity 88% (95% CI 84% to 92%). In the seven studies reporting the impact of applying a threshold of 10 µg/L, pooled sensitivity was 68% (95% CI 53% to 79%) and pooled specificity 97% (95% CI 90% to 99%).

AUTHORS' CONCLUSIONS

CEA is insufficiently sensitive to be used alone, even with a low threshold. It is therefore essential to augment CEA monitoring with another diagnostic modality in order to avoid missed cases. Trying to improve sensitivity by adopting a low threshold is a poor strategy because of the high numbers of false alarms generated. We therefore recommend monitoring for colorectal cancer recurrence with more than one diagnostic modality but applying the highest CEA cut-off assessed (10 µg/L).

Impact of delay between imaging and treatment in patients with potentially curable pancreatic cancer

Background

Locoregional pancreatic ductal adenocarcinoma (PDAC) may progress rapidly and/or disseminate despite having an early stage at diagnostic imaging. A prolonged interval from imaging to resection might represent a risk factor for encountering tumour progression at laparotomy. The aim of this study was to determine the therapeutic window for timely surgical intervention.

Methods

This observational cohort study included patients with histologically confirmed PDAC scheduled for resection with curative intent from 2008 to 2014. The impact of imaging-to-resection/reassessment (IR) interval, vascular involvement and tumour size on local tumour progression or presence of metastases at reimaging or laparotomy was evaluated using univariable and multivariable regression. Risk estimates were approximated using hazard ratios (HRs).

Results

Median IR interval was 42 days. Of 349 patients scheduled for resection, 82 had unresectable disease (resectability rate 76·5 per cent). The unresectability rate was zero when the IR interval was 22 days or shorter, and was lower for an IR interval of 32 days or less compared with longer waiting times (13 versus 26·2 per cent; HR 0·42, P = 0·021). It was also lower for tumours smaller than 30 mm than for larger tumours (13·9 versus 32·5 per cent; HR 0·34, P &lt; 0·001). Tumours with no or minor vascular involvement showed decreased rates of unresectable disease (20·6 per cent versus 38 per cent when there was major or combined vascular involvement; HR 0·43, P = 0·007). However, this failed to reach statistical significance on multivariable analysis (P = 0·411), in contrast to IR interval (P = 0·028) and tumour size (P &lt; 0·001).

Conclusion

Operation within 32 days of diagnostic imaging reduced the risk of tumour progression to unresectable disease by half compared with a longer waiting time. The results of this study highlight the importance of efficient clinical PDAC management.

Cost-effectiveness of diagnostic laparoscopy for assessing resectability in pancreatic and periampullary cancer

Background

Surgical resection is the only curative treatment for pancreatic and periampullary cancer, but many patients undergo unnecessary laparotomy because tumours can be understaged by computerised tomography (CT). A recent Cochrane review found diagnostic laparoscopy can decrease unnecessary laparotomy. We compared the cost-effectiveness of diagnostic laparoscopy prior to laparotomy versus direct laparotomy in patients with pancreatic and periampullary cancer with resectable disease based on CT scanning.

Method

Model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs) per patient from the perspective of the UK National Health Service. A decision tree model was constructed using probabilities, outcomes and cost data from published sources. One-way and probabilistic sensitivity analyses were undertaken.

Results

When laparotomy following diagnostic laparoscopy occurred in a subsequent admission, diagnostic laparoscopy incurred similar mean costs per patient to direct laparotomy (£7470 versus £7480); diagnostic laparoscopy costs (£995) were offset by avoiding unnecessary laparotomy costs. Diagnostic laparoscopy produced significantly more mean QALYs per patient than direct laparotomy (0.346 versus 0.337). Results were sensitive to the accuracy of diagnostic laparoscopy and the probability that disease was unresectable. Diagnostic laparoscopy had 63 to 66% probability of being cost-effective at a maximum willingness to pay for a QALY of £20 000 to £30 000. When laparotomy was undertaken in the same admission as diagnostic laparoscopy the mean cost per patient of diagnostic laparoscopy increased to £8224.

Conclusions

Diagnostic laparoscopy prior to laparotomy in patients with CT-resectable cancer appears to be cost-effective in pancreatic cancer (but not in periampullary cancer), when laparotomy following diagnostic laparoscopy occurs in a subsequent admission.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0270-x) contains supplementary material, which is available to authorized users.

Impact of the time interval between MDCT imaging and surgery on the accuracy of identifying metastatic disease in patients with pancreatic cancer

OBJECTIVE

Pancreatic adenocarcinoma is a rapidly progressive malignancy characterized by its tendency for early metastatic spread. MDCT is the primary diagnostic modality for the preoperative staging of patients with pancreatic cancer, with an accuracy established in multiple studies. However, for a variety of reasons, there is often a prolonged interval between staging MDCT and the surgical intervention. This study examines the relationship between the interval between imaging and surgery and the accuracy of MDCT in determining the presence or absence of metastatic disease at surgery in patients with pancreatic cancer.

MATERIALS AND METHODS

Patients were identified who had undergone surgery for pancreatic cancer at our institution with a dedicated preoperative pancreas-protocol MDCT performed in our department. Findings from the preoperative MDCT report were correlated with the operative findings, as well as the time between imaging and surgery.

RESULTS

Two hundred ninety-two MDCT scans were performed on 256 patients who underwent exploration for pancreatic adenocarcinoma. The patients had a median age of 67 years (range, 30-95 years), and 51.6% (132/256) were male. The median time between MDCT and surgical exploration was 15.5 days (range, 1-198 days). MDCT correctly predicted the absence of metastatic disease at surgery in 233 of 274 (85.0%) studies. MDCT was more accurate in predicting the absence of metastatic disease if the study was performed within 25 days of surgery than it was if the study was performed within more than 25 days of surgery (89.3% vs 77.0%; p = 0.0097). Furthermore, regression models showed that the negative predictive value of a given MDCT significantly decreased after approximately 4 weeks.

CONCLUSION

MDCT is an accurate method to stage patients with pancreatic cancer, but its accuracy in excluding distant metastatic disease depreciates over time. Patients should undergo a repeat MDCT within 25 days of any planned definitive operative intervention for pancreatic cancer to avoid unexpectedly finding metastatic disease at surgery.