Value-of-information analysis to guide future research in the management of the colorectal malignant polyp

Pathological features associated with metastasis in patients with early invasive (pT1) colorectal carcinoma in colorectal polyps

AIMS

Colorectal carcinoma (CRC) arising in a colorectal polyp with invasion limited to the submucosa is sufficiently treated by complete endoscopic resection alone in many cases. Histological features of the carcinoma including tumour size, vascular invasion and poor tumour differentiation or evidence of de-differentiation, such as tumour budding, are associated with a higher risk for metastasis such that oncological resection is recommended. However, most malignant polyps with these features do not have lymph node metastases at the time of resection, so there is a need for better refinement of the histological risk features.

METHODS AND RESULTS

A total of 437 consecutive colorectal polyps with submucosal invasive carcinoma from a single centre, 57 of which had metastatic disease, were supplemented by 30 cases with known metastatic disease from two additional centres. Clinical and histological features of the polyp cancers were reviewed looking for differences between the 87 cancers with metastatic disease and the remaining cases without metastasis. A subgroup of 204 polyps removed intact was also analysed to ensure maximum histological accuracy.

CONCLUSIONS

This study confirmed larger invasive tumour size, vascular invasion and poor tumour differentiation as adverse predictive features. Prominent peritumoral desmoplasia and high cytological grade were additional adverse features. A predictive logistic regression model comprised of (i) presence of any form of vascular invasion; (ii) presence of high tumour budding (BD3); (iii) width of invasive tumour component > 8 mm; (iv) depth of invasive tumour > 1.5 mm; and (v) the finding of prominent expansile desmoplasia located within and beyond the deep invasive edge of the carcinoma, showed excellent performance in predicting metastatic disease.

pT1 Colorectal Cancer Detected in a Colorectal Cancer Mass Screening Program: Treatment and Factors Associated with Residual and Extraluminal Disease

Simple Summary

Our study has evaluated the burden of pT1 CRC (confined to submucosa) detected during the first round of a CRC screening program, the surgery related complications and the factors related to four relevant outcomes: initial endoscopic resection, surgery rescue and residual disease after endoscopic resection and, finally, extraluminal disease after surgical resection. 38% of the CRC were detected in this stage.74.9% were initially resected endoscopically and 43.8% did not require surgery. There were inhospital surgical complications in 30.7%, mainly mild with no death and complications after discharge in 16.3% of the patients Residual disease was detected in 12 (4.3%) after endoscopic resection and extraluminal disease in 18 (8.6%) patients after surgery. We have determined several variables independently associated with the four outcome variables evaluated.

Abstract

The aim of this study is to describe the treatment of pT1 colorectal cancer (CRC) in a mass screening program, the surgery-related complications and the factors associated with residual disease after endoscopic resection and extraluminal disease after surgery. We included in this retrospective analysis all the pT1 CRC detected in the Galician CRC screening program between May 2013 and June 2019. We determined which variables were independently associated with the outcomes of the study through a multivariable logistic regression analysis. We included 370–354 pT1 N0(X), 16 pT1N1- out of the 971 CRC detected; 277 (74.9%) were resected endoscopically and 162 (43.8%) were not referred to surgery. There were surgical complications in 30.7% and 16.3% of the patients during hospitalization and after discharge. Residual disease was detected in 12 (4.3%) after endoscopic resection and extraluminal disease in 18 (8.6%) patients after surgery. The variables independently associated with initial endoscopic resection were a pedunculated morphology (OR 33.1, 95% CI 4.3–254), a diameter ≥ 20 mm (OR 3.94, 95% CI 1.39–11.18) and a Site–Morphology–Size–Access score < 9 (OR 428, 95% CI 42–4263). The variables related with surgery rescue were a piecemeal resection (OR 4.48, 95% CI 1.48–13.6), an infiltrated/nonevaluable resection border (OR 7.44, 95% CI 2.12–26.0), a non-well-differentiated histology (OR 4.76, 95% CI 1.07–20.0), vascular infiltration (OR 8.24, 95% CI 2.72–25.0) and a Haggitt 4 infiltration of the submucosa (OR 5.68, 95% CI 2.62–12.3). Residual disease after endoscopic resection was associated with an infiltrated/nonevaluable resection border (OR 34.9, 95% CI 4.08–298), a non-well-differentiated histology (OR 6.67, 95% CI 1.05–50.0), and the vascular infiltration of the submucosa (OR 7.61, 95% CI 1.55–37.4). The variables related with extraluminal disease after surgical resection were no endoscopic resection (OR 4.34, 95% CI 1.26–14.28), a non-well-differentiated histology (OR 4.35, 95% CI 1.39–14.29) and the lymphatic infiltration of the submucosa (OR 4.8, 95% CI 1.32–17.8). In a CRC screening program, although most of pT1 CRC are candidates for endoscopic treatment, surgery is a safe procedure. We have defined some easy to evaluate variables that can be used in the decision-making process.

Pathologist second opinion significantly alters clinical management of pT1 endoscopically resected colorectal cancer

We retrospectively collected a series of 82 endoscopically removed early colorectal cancers. Histological specimens were revised by two gastrointestinal pathologists, performing a re-evaluation of all risk factors for lymph node metastasis. The comparison between second opinion and first pathological report revealed that lymphovascular invasion and tumor grading showed a lower level of concordance than other parameters. Our results demonstrated that second opinion modified risk assessment in about 10% of cases. It was mainly due to a lack in reporting of some parameters at the first diagnosis and a different evaluation in second opinion for updated guidelines. Considering the subgroup of patients with modified risk assessment, clinical data revealed that tumors, re-classified as low risk, did not develop lymph node metastasis that, conversely, occurred in patients identified as high risk by second opinion. In conclusion, second opinion significantly alters risk perception of endoscopically removed early colorectal carcinomas representing a valuable tool for their appropriate clinical management.

Endoscopic surveillance after colonic polyps and colorrectal cancer resection. 2018 update

There is limited scientific evidence available to stratify the risk of developing metachronous colorectal cancer after resection of colonic polyps and to determine surveillance intervals and is mostly based on observational studies. However, while awaiting further evidence, the criteria of endoscopic follow-up needs to be unified in our setting. Therefore, the Spanish Association of Gastroenterology, the Spanish Society of Family and Community Medicine, the Spanish Society of Digestive Endoscopy, and the Colorectal Cancer Screening Group of the Spanish Society of Epidemiology, have written this consensus document, which is included in chapter 10 of the "Clinical Practice Guideline for Diagnosis and Prevention of Colorectal Cancer. 2018 Update". Important developments will also be presented as regards the previous edition published in 2009. First of all, situations that require and do not require endoscopic surveillance are established, and the need of endoscopic surveillance of individuals who do not present a special risk of metachronous colon cancer is eliminated. Secondly, endoscopic surveillance recommendations are established in individuals with serrated polyps. Finally, unlike the previous edition, endoscopic surveillance recommendations are given in patients operated on for colorectal cancer. At the same time, it represents an advance on the European guideline for quality assurance in colorectal cancer screening, since it eliminates the division between intermediate risk group and high risk group, which means the elimination of a considerable proportion of colonoscopies of early surveillance. Finally, clear recommendations are given on the absence of need for follow-up in the low risk group, for which the European guidelines maintained some ambiguity.

Clinical outcome of low- and high-risk malignant colorectal polyps: results of a population-based study and meta-analysis of the available literature

Some histological features of malignant polyps have been used to classify patients into low- and high-risk groups. This study proposed to evaluate the impact of this classification on the clinical outcome of patients with malignant polyps. Through the Colorectal Cancer Registry, 105 patients with endoscopically removed malignant polyps were selected. The presence of one of the following histological features defined malignant polyps as high-risk: infiltrated resection-margin, poorly differentiated carcinoma, lymphatic/vascular invasion and tumour budding and depth of submucosal invasion. Available literature was reviewed by applying a similar classification. Most of the malignant polyps were pedunculated and were localized in the left colon. Fifty-five malignant polyps were classified as low-risk lesions and 50 as high-risk. None of the patients at low-risk died of colorectal cancer. Of the patients at high-risk, three died of cancer; all three cases showed lymphatic/vascular invasion. Review of the literature reveals that an unfavourable clinical outcome is significantly more prevalent in the high-risk compared with the low-risk group (p > 0.005). Moreover, all histological risk factors show a specific predictive value of clinical adverse outcome. Our study and the pooled data analysis confirmed the usefulness of the subdivision into low- and high-risk malignant polyps for management of patients with endoscopically removed colorectal carcinoma.

Value of information analysis from a societal perspective: a case study in prevention of major depression

OBJECTIVES

Productivity losses usually have a considerable impact on cost-effectiveness estimates while their estimated values are often relatively uncertain. Therefore, parameters related to these indirect costs play a role in setting priorities for future research from a societal perspective. Until now, however, value of information analyses have usually applied a health care perspective for economic evaluations. Hence, the effect of productivity losses has rarely been investigated in such analyses. The aim of the current study therefore was to investigate the effects of including or excluding productivity costs in value of information analyses.

METHODS

Expected value of information analysis (EVPI) was performed in cost-effectiveness evaluation of prevention from both societal and health care perspectives, to give us the opportunity to compare different perspectives. Priorities for future research were determined by partial EVPI. The program to prevent major depression in patients with subthreshold depression was opportunistic screening followed by minimal contact psychotherapy.

RESULTS

The EVPI indicated that regardless of perspective, further research is potentially worthwhile. Partial EVPI results underlined the importance of productivity losses when a societal perspective was considered. Furthermore, priority setting for future research differed according to perspective.

CONCLUSIONS

The results illustrated that advise for future research will differ for a health care versus a societal perspective and hence the value of information analysis should be adjusted to the perspective that is relevant for the decision makers involved. The outcomes underlined the need for carefully choosing the suitable perspective for the decision problem at hand.

A systematic and critical review of the evolving methods and applications of value of information in academia and practice

OBJECTIVE

This article provides a systematic and critical review of the evolving methods and applications of value of information (VOI) in academia and practice and discusses where future research needs to be directed.

METHODS

Published VOI studies were identified by conducting a computerized search on Scopus and ISI Web of Science from 1980 until December 2011 using pre-specified search terms. Only full-text papers that outlined and discussed VOI methods for medical decision making, and studies that applied VOI and explicitly discussed the results with a view to informing healthcare decision makers, were included. The included papers were divided into methodological and applied papers, based on the aim of the study.

RESULTS

A total of 118 papers were included of which 50 % (n = 59) are methodological. A rapidly accumulating literature base on VOI from 1999 onwards for methodological papers and from 2005 onwards for applied papers is observed. Expected value of sample information (EVSI) is the preferred method of VOI to inform decision making regarding specific future studies, but real-life applications of EVSI remain scarce. Methodological challenges to VOI are numerous and include the high computational demands, dealing with non-linear models and interdependency between parameters, estimations of effective time horizons and patient populations, and structural uncertainties.

CONCLUSION

VOI analysis receives increasing attention in both the methodological and the applied literature bases, but challenges to applying VOI in real-life decision making remain. For many technical and methodological challenges to VOI analytic solutions have been proposed in the literature, including leaner methods for VOI. Further research should also focus on the needs of decision makers regarding VOI.

Immunohistochemical alterations in invasive adenocarcinoma in endoscopically resected adenoma and factors associated with risk of residual or recurrent disease

AIM

We determined the pattern of immunohistochemical expression in invasive adenocarcinoma in endoscopically resected adenoma, its relationship with the risk of residual or recurrent disease and the related factors.

METHOD

We included individuals with malignant polyps resected endoscopically in the period 1999-2009. Clinical and endoscopic data were collected. All histological specimens were re-analysed. CD44, matrix metalloproteinase 9 (MMP-9), vascular endothelial growth factor-β (VEGF-β), β-catenin, laminin and cyclooxygenase 2 (COX-2) expression were determined by immunohistochemistry. A multivariate logistic regression was performed to determine variables independently associated with the risk of residual or recurrent disease.

RESULTS

One-hundred and fifty-one malignant polyps (114 pedunculated; mean size ± SD=22.61 ± 10.86 mm) were resected endoscopically. Resection was fragmented and incomplete in 26.5% and 8.6% of patients, respectively. Surgical resection was performed on 71 (47%) patients. After a median follow-up of 44 months, residual (n=12) or recurrent (n=6) disease was detected in 17 patients. Conventional histology showed that 32.1% met high-risk histological criteria. Immunohistochemical expression was positive for CD44, MMP-9, VEGF-β, β-catenin, laminin and COX-2 in 63.3%, 25.3%, 45%, 38.8%, 79% and 34.5% of specimens, respectively, with no differences between both groups. Variables associated with residual or recurrent disease in the univariate analysis were: nonpedunculated morphology (P=0.07); fragmented (P<0.001) or incomplete resection (P<0.001); margin infiltration (P=0.04); and histological high-risk lesion (P=0.003). Finally, incomplete resection (OR=12.16, 95% CI=3.15-46.98; P<0.001) and histological high risk (OR=4.73, 95% CI=1.33-16.74; P=0.002) were independently associated with the risk of residual or recurrent disease.

CONCLUSION

Immunohistochemistry could not predict residual or recurrent disease. Only incomplete excision and histological high risk did so. The factors independently associated were histological high-risk lesion and incomplete resection.

When to wait for more evidence? Real options analysis in proton therapy

PURPOSE

Trends suggest that cancer spending growth will accelerate. One method for controlling costs is to examine whether the benefits of new technologies are worth the extra costs. However, especially new and emerging technologies are often more costly, while limited clinical evidence of superiority is available. In that situation it is often unclear whether to adopt the new technology now, with the risk of investing in a suboptimal therapy, or to wait for more evidence, with the risk of withholding patients their optimal treatment. This trade-off is especially difficult when it is costly to reverse the decision to adopt a technology, as is the case for proton therapy. Real options analysis, a technique originating from financial economics, assists in making this trade-off.

METHODS

We examined whether to adopt proton therapy, as compared to stereotactic body radiotherapy, in the treatment of inoperable stage I non-small cell lung cancer. Three options are available: adopt without further research; adopt and undertake a trial; or delay adoption and undertake a trial. The decision depends on the expected net gain of each option, calculated by subtracting its total costs from its expected benefits.

RESULTS

In The Netherlands, adopt and trial was found to be the preferred option, with an optimal sample size of 200 patients. Increase of treatment costs abroad and costs of reversal altered the preferred option.

CONCLUSION

We have shown that real options analysis provides a transparent method of weighing the costs and benefits of adopting and/or further researching new and expensive technologies.

Clinical features and prognosis of early colorectal cancer treated by endoscopic mucosal resection

BACKGROUND AND AIMS

The incidence of early colorectal cancer (ECC) has been increasing. The aim of this study was to evaluate the clinical outcome and prognosis of ECC treated by endoscopic mucosal resection (EMR).

METHODS

A total of 129 ECC patients who were initially treated by EMR between April 2005 and August 2007 were enrolled. Clinicopathological characteristics and prognoses were evaluated retrospectively.

RESULTS

En bloc resection was performed in 85% of ECC patients, and piecemeal resection was performed in 15% of patients. Clear lateral and deep margins were achieved in 86% of cases. Of the 129 patients, 64 were found to have intramucosal cancer and 65 had submucosal cancer. Clinical characteristics were not different between patients with intramucosal cancer and submucosal cancer; however, poor differentiation and the absence of background adenoma showed significant association with submucosal cancer. Seven patients with submucosal cancer underwent subsequent surgical resection; five had lymphovascular invasion or a positive resection margin, one had perforation, and one patient requested surgical resection. Of these seven patients, one had residual cancer and two had lymph node metastasis. All patients with intramucosal cancer had no recurrence during the follow-up period. Seven patients with submucosal cancer showed adverse outcomes within 3 years, such as residual/recurrence of primary cancer or lymph node metastasis; five showed lymphovascular invasion or a positive deep margin, and two had no histological risk factors.

CONCLUSIONS

Our results suggest that intramucosal cancer shows good prognosis, and a cure could be expected after EMR; however, adverse outcomes can occur in submucosal cancer. Therefore, meticulous endoscopic follow up is needed in patients with submucosal cancer for at least 3 years after EMR.