Person:

Padera, Timothy

Background: Thoracic and cardiac irradiation increases the risk of pulmonary and cardiovascular disease. In addition, radiation, often in combination with chemotherapy, can cause treatment-related pneumonitis. Previously, we showed that the common marker for cardiac damage, troponin T, was not elevated by chemoradiation [Lung Cancer 62:351–355, 2008]. In this study, we explore whether dose-volume metrics and biomarkers for cardiac damage, inflammation or angiogenesis could identify patients receiving thoracic radiation who would later have cardiac or pulmonary complications. Findings: To this end, we quantified cardiac biomarkers including c-reactive protein (cRP) as well as a panel of angiogenic and inflammatory molecules in thirty patients who received radiation therapy to the thorax with or without concurrent chemotherapy between May 2006 and May 2007. Serum was collected at baseline, 2 weeks into radiation treatment and at the completion of radiation therapy. Heart and lung dosimetric parameters and clinical risk factors were also examined, along with the monitoring of adverse pulmonary and cardiac events during follow-up. Contrary to our hypothesis, there was no correlation between serum biomarker levels and cardiac radiation dose. Similarly there was little association between lung dose-volume metrics and inflammatory or angiogenic biomarkers. Furthermore, there was no correlation with serum biomarkers and adverse pulmonary or cardiovascular events. Conclusion: Based on these data, acute elevations in serum biomarkers of cardiac damage, inflammation or angiogenesis should not be attributed to thoracic (chemo)radiation and elevations in such biomarkers of tissue damage should be further evaluated.

Solid stress and tissue stiffness affect tumour growth, invasion, metastasis and treatment. Unlike stiffness, which can be precisely mapped in tumours, the measurement of solid stresses is challenging. Here, we show that two-dimensional spatial mappings of solid stress and the resulting elastic energy in excised or in situ tumours with arbitrary shapes and wide size ranges can be obtained via three distinct and quantitative techniques that rely on the measurement of tissue displacement after disruption of the confining structures. Application of these methods in models of primary tumours and metastasis revealed that: (i) solid stress depends on both cancer cells and their microenvironment; (ii) solid stress increases with tumour size; and (iii) mechanical confinement by the surrounding tissue significantly contributes to intratumoural solid stress. Further study of the genesis and consequences of solid stress, facilitated by the engineering principles presented here, may lead to significant discoveries and new therapies.