Date Published: April 5, 2018
Publisher: Public Library of Science
Author(s): Lionel Perrier, Pauline Rascle, Magali Morelle, Maud Toulmonde, Dominique Ranchere Vince, Axel Le Cesne, Philippe Terrier, Agnès Neuville, Pierre Meeus, Fadila Farsi, Françoise Ducimetière, Jean-Yves Blay, Isabelle Ray Coquard, Jean-Michel Coindre, Dominique Heymann.
This study examined the types of discordance occurring in the diagnosis of soft tissue and visceral sarcomas, gastrointestinal stromal tumors (GIST), and desmoid tumors, as well as the economic impact of diagnostic discrepancies.
We carried out a retrospective, multicenter analysis using prospectively implemented databases performed on a cohort of patients within the French RRePS network in 2010. Diagnoses were deemed to be discordant based on the 2013 World Health Organization (WHO) classification. Predictive factors of discordant diagnoses were explored. A decision tree was used to assess the expected costs of two strategies of disease management: one based on revised diagnoses after centralized histological review (option 1), the other on diagnoses without centralized review (option 2). Both were defined based on the patient and the disease characteristics, according to national or international guidelines. The time horizon was 12 months and the perspective of the French National Health Insurance (NHI) was retained. Costs were expressed in Euros for 2013. Sensitivity analyses were performed using low and high scenarios that included ± 20% estimates for cost.
A total of 2,425 patients were included. Three hundred forty-one patients (14%) had received discordant diagnoses. These discordances were determined to mainly be benign tumors diagnosed as sarcomas (n = 124), or non-sarcoma malignant tumors diagnosed as sarcomas (n = 77). The probability of discordance was higher for a final diagnosis of desmoid tumors when compared to liposarcomas (odds ratio = 5.1; 95%CI [2.6–10.4]). The expected costs per patient for the base-case analysis (low- and high-case scenarios) amounted to €8,791 (€7,033 and €10,549, respectively) for option 1 and €8,904 (€7,057 and €10,750, respectively) for option 2.
Our findings highlight misdiagnoses of sarcomas, which were found to most often be confused with benign tumors. Centralized histological reviews are likely to provide cost-savings for the French NHI.
Discordant diagnoses are known to occur for most malignancies, with a wide range of discordance rates due mainly to the use of variable definitions for discordance, the nature of the histological review used (i.e., a second opinion request vs. systematic review), and the tumor type [1–7]. Nevertheless, the use of a histological review to improve the accuracy of histological diagnosis in oncology, particularly with rare cancers, has recently received considerable attention due to increased efforts to enhance institutional performance and to reduce medical errors [4, 6, 8–12]. In light of the value of histological review, policies in support of its use in oncology have become more prevalent [13, 14].
Our results should assist with defining health policies regarding the organization of histological review of sarcomas, GIST, and desmoid tumors from both clinical and economic points of view. From a clinical perspective, initial diagnoses sent either for second opinion or systematic review according to the French National Cancer Institute (INCa) recommendations increased the probability of discordance as compared to a primary analysis within the RRePS network. From an economic perspective, centralized histological reviews lower the cost of patient disease management for the French NHI. Moreover, our findings shed light on the overdiagnosis of sarcoma, which was found to most often be confused with benign tumors. Care should also be taken when diagnosing desmoid tumors, as they similarly exhibit high rates of discordance.