WEDNESDAY, Oct. 30, 2024 -- A health care system employing filtering functions before biopsy of skin lesions can achieve a low benign-to-malignant ratio (BMR), according to a study published online Oct. 12 in the Journal of the European Academy of Dermatology & Venereology.

Gustav G. Nervil, from Copenhagen University Hospital in Denmark, and colleagues examined the number and costs of skin biopsies in Denmark over 15 years, focusing on benign and malignant skin lesions and melanomas. The BMR and number needed to biopsy (NNB) were determined, and the direct cost of benign skin lesion biopsies was estimated in the Cancer Pathway.

A total of 4,481,207 biopsy samples were included from January 2007 to June 2022 from the Danish Pathology Data Bank; 151,988 of these from the Cancer Pathway were included in the primary analysis of BMR. The researchers found that from 2007 to 2021, there was a 39.1 percent increase in the number of biopsies. The overall BMR was 4.1:1 for malignancy, and NNB was 31.8 for melanoma. Among biopsies performed on clinical suspicion of malignancy or melanoma, the BMR was 1.5:1 and NNB was 2.8. In 2021, the cost of benign skin biopsies performed on suspicion of cancer or melanoma was €6.6 million, mainly in hospitals.

"A health care system that employs easy and swift access to filtering functions before biopsy of skin lesions can achieve a BMR as low as 1.5:1, NNB of 2.8, and an underdiagnosis rate of 1 in 161, but it carries a heavy toll on the public health care system," the authors write.