Prospective Versus Retrospective Study of Comorbidity and Complications in Relation to Radical Cystectomy and Nephrectomy

Background:

Today there are many different systems to classify co morbidity and complication of radical cystectomy and nephrectomy. Regarding complication, there is Clavien Dindo classifications System and The National Surgical Quality Improvement Program (NSQIP) while Charlson Comorbidity Index (CCI) and Eastern Cooperative Oncology Group (ECOG) performance scale classifies comorbidity. At the present time, there is not a system that takes both parameters into account, although it is of high clinical relevance to be able to figure out the significant and important patient parameters that can influence the outcome of a treatment modality. Such a system is in development, from cystectomy patients, in this study's project group. This is currently to be validated in two large patient cohorts from respectively Herlev Hospital and Memorial Sloan Kettering Cancer Center, New York, USA. Virtually all previous publications on comorbidity or complications after cancer surgery, including the aforementioned, is based on data retrospectively collected from medical records. Even prospectively maintained database are based predominantly on data from records written in the journal prospective, but then transferred retrospectively to the database. The problem is that data on comorbidities and complications are not collected with this registration method in mind. Especially in the definition of the individual complications this contains a significant source of error. In addition, most minor complications that do not require re-intervention or re-operation, are probably underreported. Involvement of lesser complications after discharge is rarely reported, unless they lead to readmission. This is probably one of the causes of an uneven distribution in the reporting of serious complications requiring re-operation when comparing surgical case series, while the number of minor complications (Clavien 1-2) are highly variable. Even a minor complication which does not cause a readmission, can have a major impact on a patient's quality of life and experience of the disease. In addition, the small complications are often preventable, if you have a knowledge of their cause and context with the intervention. Patients who are to undergo cystectomy, are predominantly elderly patients with a large tobacco consumption and high comorbidity. At the same time cystectomy is associated with the highest risk of complications (75%) in cancer surgery, followed by nephrectomy patients (20%). Kidney cancer, and especially bladder cancer has a high- 1- and 5-year survivalrate. The patients will likely live for many years with their complications and the potential impact on quality of life as a result.

Since current knowledge and previous publications on comorbidity and/or complications after cancer surgery often is build on retrospective collected data, it will be highly relevant to examine the extent to which the retrospectively collected data is accurate by comparing with prospectively collected data. By conducting this study, it can be assessed which kind of gathering gives the correct information on the complications of radical cancer surgery and if previous publications should be revalidated?

Aim of the study The study will examine which differences there are in comorbidity and complications collected retrospectively from medical records compared with data collected prospectively.

Hypothesis The prevalence of registered comorbidity and minor complications in patients who have undergone radical cystectomy or nephrectomy, will increase if the data collection is focused and prospective, compared with retrospectively collected data.