External validation of the RIETE and SOME scores for occult cancer in patients with venous thromboembolism: a multicentre cohort study.

Introduction: Venous thromboembolism (VTE) may be the first sign of an undiagnosed cancer. The RIETE and SOME scores aim to identify patients with acute VTE at high risk of occult cancer. In the present study, we evaluated the performance of both scores.

Methods: The scores were evaluated in a retrospective cohort from two centers. The area under the receiver-operating characteristics curve (AUC) evaluated the discriminatory performance.

Results: The RIETE score was applied to 815 patients with provoked and unprovoked VTE, of whom 56 (6.9%) were diagnosed with cancer. Of the 203 patients classified as high-risk, 18 were diagnosed with cancer, representing 32.1% (18/56) of the total cancer diagnoses. In the group of 612 low-risk patients, 67.9% of the cancer cases were diagnosed (38/56). Sensitivity, specificity, negative and positive predictive values, and AUC were 32%, 76%, 94%, 9%, and 0.430 (95% confidence interval [CI], 0.38‒0.47), respectively. The SOME score could be calculated in 418 patients with unprovoked VTE, of whom 33 (7.9%) were diagnosed with cancer. Of the 45 patients classified as high-risk, three were diagnosed with cancer, representing 9.1% (3/33) of the total cancer diagnoses. In the group of 373 low-risk patients, 90.9% of the cancer cases were diagnosed (30/33). Sensitivity, specificity, negative and positive predictive values, and AUC were 33%, 88%, 94%, 20%, and 0.351 (95% CI, 0.27‒0.43), respectively.

Conclusions: The performance of both scores was poor. Our results highlight the need to develop new models to identify high-risk patients who may benefit from an extensive cancer screening strategy.