Comprehensive measurement of UVB-induced non-melanoma skin cancer burden in mice using photographic images as a substitute for the caliper method

Abstract

The vernier caliper has been used as a gold standard to measure the length, width and height of skin tumors to calculate their total area and volume. It is a simple method for collecting data on a few tumors at a time, but becomes tedious, time-consuming and stressful for the animals and the operator when used for measuring multiple tumors in a large number of animals in protocols such as UVB-induced non-melanoma skin cancer (NMSC) in SKH-1 mice. Here, we show that photographic images of these mice taken within a few minutes under optimized conditions can be subjected to computerized analyses to determine tumor volume and area as accurately and precisely as the caliper method. Unlike the caliper method, the photographic method also records the incidence and multiplicity of tumors, thus permitting comprehensive measurement of tumor burden in the animal. The simplicity and ease of this method will permit more frequent monitoring of tumor burden in long protocols, resulting in the creation of additional data about dynamic changes in progression of cancer or the efficacy of therapeutic intervention. The photographic method can broadly substitute the caliper method for quantifying other skin pathologiesGrant: This work was supported by the grants to GMS from Natural Sciences and Engineering Research Council of Canada (Discovery Grants # RGPIN-2016-05868 and Discovery Accelerator Grant # RGPAS-492875-2016). NKP received a foreign student fee-waiver scholarship from Quebec Government and Shastri Indo-Canadian Institute. NKP was also a recipient of the graduate scholarships from the Neuroscience Axis of CR- CHU-Q. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.