Abstract 1365: The PAMM (pulmonary assessment of metastatic morbidity) diagnostic: A novel non-invasive method for evaluating lung metastasis in murine models

Abstract

Abstract Metastasis continues to be the most significant problem in the field of cancer. The biological complexity that characterizes metastasis requires relevant experimental systems for its study, necessitating the use of animal models. When using murine models for pulmonary metastasis, it is valuable to conduct longitudinal studies during which progression of metastatic burden in the lung occurs. Current methods for evaluating pulmonary metastatic burden in experimental mice are limited to advanced imaging approaches or to the development of morbidity linked to pulmonary metastasis. Unfortunately, clinical signs of morbidity are often vague and unpredictable. A novel, inexpensive, clinical method to detect advanced metastatic burden in mice before the development of significant morbidity or mortality would be beneficial to the study of metastasis in mice. With this goal in mind we have developed a novel, non-invasive technique for assessing pulmonary metastatic burden in laboratory mice. The PAMM (Pulmonary Assessment of Metastatic Morbidity) test is performed by restraining an awake mouse and gently applying pressure with the index finger under the xiphoid process. This pressure reduces the diaphragmatic component to respiration. Mice with advanced lung metastases will show signs of respiratory distress within 3 seconds of applying this pressure. Application of this method in 4 models of pulmonary metastasis (n=27 mice including sarcoma and mammary carcinoma histologies), amongst 3 independent “users,” yielded 100% positive and 100% negative predictive values that were validated by post mortem examination. In summary, the PAMM method is a simple, inexpensive, reproducible and efficient method to assist in the detection of advanced pulmonary metastasis. This method contributes to the humane care of mice included in longitudinal studies of pulmonary metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1365. doi:1538-7445.AM2012-1365