Completeness and registration bias in PROCARE, a Belgian multidisciplinary project on cancer of the rectum with participation on a voluntary basis

Completeness and selection bias of a Belgian multidisciplinary, registration-based study on the EFFectiveness and quality of Endometrial Cancer Treatment (EFFECT)

BACKGROUND

With the aim of obtaining more uniformity and quality in the treatment of corpus uteri cancer in Belgium, the EFFECT project has prospectively collected detailed information on the real-world clinical care offered to 4063 Belgian women with primary corpus uteri cancer. However, as data was collected on a voluntary basis, data may be incomplete and biased. Therefore, this study aimed to assess the completeness and potential selection bias of the EFFECT database.

METHODS

Five databases were deterministically coupled by use of the patient's national social security number. Participation bias was assessed by identifying characteristics associated with hospital participation in EFFECT, if any. Registration bias was assessed by identifying patient, tumor and treatment characteristics associated with patient registration by participating hospitals, if any. Uni- and multivariable logistic regression were applied.

RESULTS

EFFECT covers 56% of all Belgian women diagnosed with primary corpus uteri cancer between 2012 and 2016. These women were registered by 54% of hospitals, which submitted a median of 86% of their patients. Participation of hospitals was found to be biased: low-volume and Walloon-region centers were less likely to participate. Registration of patients by participating hospitals was found to be biased: patients with a less favorable risk profile, with missing data for several clinical-pathological risk factors, that did not undergo curative surgery, and were not discussed in a multidisciplinary tumor board were less likely to be registered.

CONCLUSIONS

Due to its voluntary nature, the EFFECT database suffers from a selection bias, both in terms of the hospitals choosing to participate and the patients being included by participating institutions. This study, therefore, highlights the importance of assessing the selection bias that may be present in any study that voluntarily collects clinical data not otherwise routinely collected. Nevertheless, the EFFECT database covers detailed information on the real-world clinical care offered to 56% of all Belgian women diagnosed with corpus uteri cancer between 2012 and 2016, and may therefore act as a powerful tool for measuring and improving the quality of corpus uteri cancer care in Belgium.

The Value of Clinical Colorectal Cancer Registries in Colorectal Cancer Research: A Systematic Review

Importance

Clinical colorectal cancer registries (CCCRs) are potentially powerful tools in colorectal cancer research. They are resource intensive, but to our knowledge, no formal review of their value exists. While quality control, clinical audit, and benchmarking are important factors in assessing the value of maintaining CCCRs, they are difficult to quantify. This study focuses on registry research output as a measure of value; the study hypothesizes that CCCRs do not produce sufficient published research output of clinical significance to justify the resources required to maintain them.

Objective

To assess the value of maintaining CCCRs by identifying and characterizing existing CCCRs and measuring their comparative research impact.

Evidence Review

We searched MEDLINE (PubMed) and Google Scholar for articles published from January 1990 to July 2016 that identified multi-institutional CCCRs with peer-reviewed published outcomes. Purely population-based registries were excluded. We then searched the same databases in the same time period for articles that were published by each included CCCR. The articles must have been based on outcomes relating to individual CCCR data. We categorized published outcomes into oncological, surgical, or other outcomes. We measured the research impact of each CCCR using the number of articles, citation index, impact factor, and Altmetric score.

Findings

A total of 18 CCCRs were identified, with sample sizes between 104 and 1 400 000 cases. Data fields, published aims, and outcomes were similar between registries. The most frequently published outcomes related to anastomotic leak following colorectal surgery. The National Cancer Database formed the basis of the highest number of publications (66), the Northern Region Colorectal Cancer Audit Group had the highest median article citation number (28.5), the National Bowel Cancer Audit had the highest median impact factor (4.72), and the National Cancer Database had the highest median Altmetric score (4.5).

Conclusions and Relevance

There is a significant body of colorectal cancer outcomes research generated from the CCCRs. However, given the enormous resources required, the overall research output and impact of CCCRs is low in proportion to the size of the data sets. These registries hold key oncological and surgical outcomes data; focusing on data linkage between registries and developing automated data collection will enable international comparisons in colorectal cancer management and will increase the research impact of CCCRs, thereby increasing their value.

The Belgian Virtual Tumorbank: A Tool for Translational Cancer Research

Background: Biobanks play a critical role in cancer research by providing high quality biological samples for research. However, the availability of tumor samples in single research institutions is often limited, especially for rare cancers. In order to facilitate the search for samples scattered among different Belgian institutions, a nationwide virtual tumorbank project was launched and is operational since February 2012. The Belgian Virtual Tumorbank (BVT) network encompasses the tumor biobanks from eleven Belgian university hospitals that collect and store residual human tumor samples locally and is coordinated by the Belgian Cancer Registry. Materials and Methods: A web application was developed and consists of two modules. The registration module (BVTr) centralizes the tumor sample data from the local partner biobanks. The catalog module (BVTc) allows researchers to trace the tumor samples in the 11 tumor biobanks. The BVTc contains patient, medical and technical data, but excludes identifying information to ensure privacy of individuals. Automatic and manual controls guarantee high quality data on the samples requested by scientists for research purposes in oncology. A major advantage of the BVT network is that the available data can be linked to the data of the Belgian Cancer Registry for quality control purposes. Results: Currently, more than 92,000 registrations are available in the catalog. Twenty-seven percent of the residual primary tumor samples originate from breast tissue, but also less frequent localisations such as head and neck (4%), male genital organs (1.7%), and urinary tract (1%) are available. In addition to the residual tumor tissue samples, also other available material can be stored and registered by the local biobanks. The most common type is corresponding normal tissue (19%).Other frequently available materials are plasma, blood, serum, DNA, and buffy coat. Even PBMCs, RNA, cytology, and urine are available in some cases. Discussion and Conclusion: The BVT catalog is a valuable source of information for oncology research and the ultimate goal is to promote multidisciplinary cancer research (i.e., pathogenesis, disease prediction, prevention, diagnosis, treatment, and prognosis) for the benefit of all cancer patients.

Effect of abdominopelvic sepsis on cancer outcome in patients undergoing sphincter saving surgery for rectal cancer

BACKGROUND

In rectal cancer, the significance of abdominopelvic sepsis (APS) on metastatic tumor growth remains uncertain. We aimed to analyze the effect of abdominopelvic sepsis on long-term survival in patients undergoing restorative rectal cancer surgery.

METHODS

Data were used from the Belgian PROCARE rectal cancer registry. The effect of abdominopelvic infection on survival was assessed in uni- and multivariable Cox regression models. The effect of clinical and pathological covariates was controlled by propensity score-based matching of cases with controls. The effect of abdominopelvic sepsis on the rate of local and metastatic recurrence was evaluated using crosstabulation and the Pearson χ² test.

RESULTS

In univariable analysis, the presence of APS was associated with significantly worse overall survival (HR 1.3, P = 0.025). After propensity score matching including age, BMI, tumor level, pTstage, pN stage, CRM, tumor grade, number of lymph nodes, and presence of lymphovascular invasion, the association of APS with OS was no longer significant (HR 1.26, 95%CI 0.92-1.74, P = 0.15). No differences were observed in the risk of local or metastatic recurrence (3.6% vs 2.9% and 13% vs 16.5%).

CONCLUSIONS

In this analysis APS after rectal cancer resection was not significantly associated with OS, metastatic, or local recurrence.

The Rationale for and Reality of the New National Accreditation Program for Rectal Cancer

BACKGROUND

The treatment of rectal cancer has greatly evolved because of numerous diagnostic and therapeutic advances. More accurate staging by MRI has allowed more appropriate use of neoadjuvant therapy as well as more standardized high-quality total mesorectal excision. Lower rates of perioperative morbidity, permanent colostomy creation, and improved rates of oncologically acceptable rectal excision have led to lower recurrence and greater disease-free survival rates. The recognition of the need for pathologic assessment of the quality of total mesorectal excision, the status of the circumferential resection margins, and the finding of a minimum of 12 lymph nodes as well as identification of extramural vascular invasion has improved staging. These evolutions in imaging, surgical management, and pathologic specimen assessment are interdependent and have been repeatedly shown on national levels to be best operationalized in a multidisciplinary team environment.

OBJECTIVE

The aim of this article is to evaluate the evidence leading to these important changes, including the imminent launch of the National Accreditation Program for Rectal Cancer.

DESIGN AND SETTING

Based on the myriad confirmatory experiences in Europe and in the United Kingdom, a multidisciplinary team rectal cancer program was designed by the Consortium for Optimizing Surgical Treatment of Rectal Cancer and subsequently endorsed and accepted by the American College of Surgeons Commission on Cancer.

MAIN OUTCOME MEASURES

The primary outcome measured is the adherence to the new program standards.

RESULTS

Surgical treatment of rectal cancer consortium membership rapidly increased from 14 centers in August 2011 to more than 350 centers in April 2017.

LIMITATIONS

The multidisciplinary team rectal cancer program has not yet launched; thus, its impact cannot yet be assessed.

CONCLUSIONS

It is our hope and expectation that the outstanding improvement in quality outcomes repeatedly demonstrated within Europe, and extensively shown as much needed in the United States, will be rapidly achieved.

Accuracy of pre-treatment locoregional rectal cancer staging in a national improvement project

BACKGROUND

The aim of this study was to assess the accuracy, particularly the predictive value, of locoregional clinical rectal cancer staging (cTN) and its variability in a national improvement project.

METHODS

cTN stages and the distance between tumour and mesorectal fascia (MRF) were compared with histopathological findings in 1168 patients who underwent radical resection without neoadjuvant treatment. Data were registered prospectively from 2006 to 2014.

RESULTS

Agreement between clinical and histopathological TN stages was 50%, independent of tumour location. Inter-hospital variability was within 99% prediction limits. Magnetic resonance imaging (MRI) was increasingly applied, but staging accuracy did not improve. Stage II-III was correctly predicted in 69% and pStage I was over-staged in 35%. The positive predictive value of endorectal ultrasonography (ERUS) for T1 lesions was 57%. MRI-based distances to MRF correlated poorly with the circumferential resection margin (r = 0.26). A negative resection margin was achieved in 91% when the distance to the MRF was >1 mm.

CONCLUSIONS

The accuracy of rectal cancer staging in general practice should be improved to avoid under- or overtreatment. Training and expert review of pre-treatment MR imaging could be helpful. A second ERUS is justified when transanal local resection for early lesions is planned.

Post-Marketing Safety Surveillance of the Salvia Miltiorrhiza Depside Salt for Infusion: A Real World Study

BACKGROUND

Salvia Miltiorrhiza Depside Salt for Infusion (SMDS) is made of a group of highly purified listed drugs. However, its safety data is still reported limitedly. Compared with the clinical trials, its safety in the real world setting is barely assessed.

OBJECTIVE

To investigate the safety issues, including adverse events (AEs), adverse events related to SMDS (ADEs), and adverse drug reactions (ADRs) of the SMDS in the real world clinical practice.

METHODS

This is a prospective, multicenter, pharmacist-led, cohort study in the real world setting. Consecutive patients prescribed with SMDS were all included in 36 sites. Pharmacists were well trained to standardized collect the patients information, including demographics, medical history, prescribing patterns of SMDS, combined medications, adverse events, laboratory investigations, outcomes of the treatment when discharge, and interventions by pharmacists. Adverse events and adverse drug reactions were collected in details. Multivariate possion regression analysis was applied to identify risk factors associated with ADEs using the significance level (α) 0.05. ClinicalTrials.gov Identifier: NCT01872520.

RESULTS

Thirty six hospitals were participated in the study and 30180 consecutive inpatients were included. The median age was 62 (interquartile range [IQR], 50-73) years, and male was 17384 (57.60%) among the 30180 patients. The incidences of the AEs, ADEs and ADRs were 6.40%, 1.57% and 0.79%, respectively. There were 9 kinds of new ADEs which were not on the approved label found in the present study. According to the multivariate analysis, male (RR = 1.381, P = 0.009, 95%CI [1.085~1.759]), more concomitant medications (RR = 1.049, P<0.001, 95%CI [1.041~1.057]), longer duration of SMDS therapy (RR = 1.027, P<0.001, 95%CI [1.013~1.041]), higher drug concentration (RR = 1.003, P = 0.014, 95%CI [1.001~1.006]), and resolvent unapproved (RR = 1.900, P = 0.002, 95%CI [1.260~2.866]) were the independent risk factors of the ADEs. Moreover, following the approved indication (RR = 0.655, P<0.001, 95%CI [0.532~0.807]) was associated with lower incidence of ADEs.

CONCLUSIONS

SMDS was well tolerated in the general population. The incidences of the AEs, ADEs and ADRs were 6.40%, 1.57% and 0.79%, respectively. Several risk factors of its ADEs have been identified. It is recommended to follow the instructions when prescribing and administrating SMDS in the real world clinical practice.

Review of the quality of total mesorectal excision does not improve the prediction of outcome

AIM

A fair to moderate concordance in grading of the total mesorectal excision (TME) surgical specimen by local pathologists and a central review panel has been observed in the PROCARE (Project on Cancer of the Rectum) project. The aim of the present study was to evaluate the difference, if any, in the accuracy of predicting the oncological outcome through TME grading by local pathologists or by the review panel.

METHOD

The quality of the TME specimen was reviewed for 482 surgical specimens registered on a prospective database between 2006 and 2011. Patients with a Stage IV tumour, with unknown incidence date or without follow-up information were excluded, resulting in a study population of 383 patients. Quality assessment of the specimen was based on three grades including mesorectal resection (MRR), intramesorectal resection (IMR) and muscularis propria resection (MPR). Using univariable Cox regression models, local and review panel histopathological gradings of the quality of TME were assessed as predictors of local recurrence, distant metastasis and disease-free and overall survival. Differences in the predictions between local and review grading were determined.

RESULTS

Resection planes were concordant in 215 (56.1%) specimens. Downgrading from MRR to MPR was noted in 23 (6.0%). There were no significant differences in the prediction error between the two models; local and central review TME grading predicted the outcome equally well.

CONCLUSION

Any difference in grading of the TME specimen between local histopathologists and the review panel had no significant impact on the prediction of oncological outcome for this patient cohort. Grading of the quality of TME as reported by local histopathologists can therefore be used for outcome analysis. Quality control of TME grading is not warranted provided the histopathologist is adequately trained.

Effect of Neoadjuvant Radiation Dose and Schedule on Nodal Count and Its Prognostic Impact in Stage II-III Rectal Cancer

BACKGROUND

It is unknown how neoadjuvant treatment schedule affects lymph node count (LNC) and lymph node ratio (LNR) and how these correlate with overall survival (OS) in rectal cancer (RC).

METHODS

Data were used from the Belgian PROCARE rectal cancer registry on RC patients treated with surgery alone, short-term radiotherapy with immediate surgery (SRT), or chemoradiation with deferred surgery (CRT). The effect of neoadjuvant therapy on LNC was examined using Poisson log-linear analysis. The association of LNC and LNR with overall survival (OS) was studied using Cox proportional hazards models.

RESULTS

Data from 4037 patients were available. Compared with surgery alone, LNC was reduced by 12.3 % after SRT and by 31.3 % after CRT (p < 0.001). In patients with surgery alone, the probability of finding node-positive disease increased with LNC, while after SRT and CRT no increase was noted for more than 12 and 18 examined nodes, respectively. Per node examined, we found a decrease in hazard of death of 2.7 % after surgery alone and 1.5 % after SRT, but no effect after CRT. In stage III patients, the LNR but not (y)pN stage was significantly correlated with OS regardless of neoadjuvant therapy. Specifically, a LNR > 0.4 was associated with a significantly worse outcome.

CONCLUSIONS

Nodal counts are reduced in a schedule-dependent manner by neoadjuvant treatment in RC. After chemoradiation, the LNC does not confer any prognostic information. A LNR of >0.4 is associated with a significantly worse outcome in stage III disease, regardless of neoadjuvant therapy type.

[Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume]

OBJECTIVE

This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals.

METHODS

Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures.

RESULTS

A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001).

CONCLUSION

Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.

Cancer patients' participation in population-based health surveys: findings from the HUNT studies

Background

The magnitude of participation bias due to non-participation should be considered for cancer patients invited to population-based surveys. We studied participation rates among persons with and without cancer in a large population based study, the Nord-Trøndelag Health Study (HUNT).

Methods

Citizens 20 years or above living in the Nord-Trøndelag County of Norway have been invited three times to comprehensive health surveys. The invitation files with data on sex, invitation date and participation were linked to the Cancer Registry of Norway. In a first step unadjusted crude participation rates (participants/invited persons) were estimated for cancer patients (CaPts) and non-cancer persons (NonCaPers), followed by logistic regression analyses with adjustment for age and sex. To evaluate the “practical” significance of the estimated odds ratios in the cancer diagnosis group, relative risks were also estimated comparing the observed rates to the estimated rates under the counterfactual assumption of no earlier cancer diagnosis among CaPts.

Results

Overall 3 % of the participants in the three HUNT studies were CaPts and 59 % of them had been diagnosed with their first life-time cancer >5 years prior to each survey. In each of the three HUNT surveys crude participation rates were similar for CaPts and NonCaPers. Adjusted for sex and age, CaPts’ likelihood to participate in HUNT1 (1984–86) and HUNT2 (1995–97), but not in HUNT3 (2006–2008), was statistically significantly reduced compared to NonCaPers, equaling a relative risk of 0.98 and 0.96, respectively. The lowest odds ratio emerged for CaPts diagnosed during the last 2 years preceding a HUNT invitation. Only one-third of CaPts participating in a survey also participated in the subsequent survey compared to approximately two-thirds of NonCaPers, and 11 % of CaPts participated in all three HUNT surveys compared to 37 % of NonCaPers.

Conclusion

In the three HUNT surveys no or only minor participation bias exist as to CaPts’ participation rates. In longitudinal studies selection bias as to long-term cancer survivorship should be taken into account, the percentage of repeatedly participating CaPts diminishing more strongly than among NonCaPers.

Scoring the quality of total mesorectal excision for the prediction of cancer-specific outcome

AIM

A three-grade system for macroscopic evaluation of the resection plane is used to describe the quality of total mesorectal excision (TME). In several studies, two of the three grades have been combined when analysing the outcome. The aim of our study was to compare the predictive value of the three-graded with that of a two-graded TME score.

METHOD

The quality of TME in 1382 patients who underwent elective resection for mid or low rectal adenocarcinoma was registered by 65 hospitals in PROCARE, a Belgian multidisciplinary improvement project. Prediction of outcome based on the classic three-grade score was compared with a two-grade scoring system in which intramesorectal resection (IMR) was combined with mesorectal (MRR) or with muscularis propria resection (MPR). End-points included the local recurrence rate, distant metastasis rate (DMR), disease-free survival (DFS) and overall survival (OS).

RESULTS

Among the 1382 resections, 63% were MRR, 27% IMR and 9% MPR. No significant differences were found in local recurrence between the different grades of TME. A two-grade score distinguishing MRR from the others was found to predict DMR, DFS and OS as well as the three-grade score.

CONCLUSION

The discriminatory and predictive value of a two-grade score, differentiating MRR from the combined IMR and MPR, was as good as the classic three-grade score.