Population-based validation of the National Cancer Comprehensive Network recommendations for baseline imaging workup of cutaneous melanoma

Abstract

The aim of the current study is to assess the performance of some of the imaging scans recommended in the National Comprehensive Cancer Network Guidelines as part of baseline staging for cutaneous melanoma, regarding the detection of lung, brain, bone, and liver metastases. Surveillance, Epidemiology and End Results database (2010-2015) was used to extract the data, and cases with cutaneous melanoma and complete information about TN stages and sites of distant metastases were explored. Performance parameters assessed in the current study included positive predictive value (PPV), negative predictive value, sensitivity, specificity, number needed to investigate (NNI), and accuracy. A total of 109 971 patients were included in the analysis. If all stage III patients in the study cohort are to be staged through routine imaging, PPV (for the recognition of lung metastases) will be 2.9% and NNI to detect one case of lung metastasis will be 34. Likewise, PPV (for the recognition of bone metastases) will be 1.8% and NNI to detect one case of bone metastasis will be 55. Moreover, PPV (for the recognition of liver metastases) will be 1.8% and NNI to detect one case of liver metastasis will be 55. Excluding stage III patients with clinically node-negative/sentinel node-positive disease would improve PPV and decrease NNI for the three metastatic sites. Adherence to current National Comprehensive Cancer Network guidelines for cutaneous melanoma imaging for baseline staging results in low rates of failure to detect asymptomatic lung, liver, brain, or bone metastases.