- Lung cancer drives vascular remodeling in its micro-environment.
- This vascular remodeling leads to the development of pulmonary hypertension.
- Dyspnea in advanced-lung cancer may be caused by immune and inflammatory processes.
To identify the causes, the lung researchers analyzed three different forms of lung cancer in mice. "These were tumor types that grow at different rates and can be experimentally induced in the lungs of mice. All three mouse models showed signs of pulmonary hypertension as tumor growth progressed," says Soni Pullamsetti, the study’s lead author.
Inflammation in blood vessels could act as trigger
But why does lung cancer often lead to pulmonary hypertension? "Neither in the patients nor in the mouse models were we able to detect any clots or cancer cells - both conceivable triggers - migrating into the vessel wall," explains Savai. However, the researchers did find that blood vessels located near tumors were infiltrated by a large number of immune cells.
Inflammation triggered by lung cancer may cause pulmonary hypertension
Further experiments showed that the immune cells release various chemical messengers, as is generally observed in inflammatory reactions. Conversely, pulmonary hypertension did not occur when the mice in the experiment lacked functioning immune cells. For the Bad Nauheim-based scientists, this is an indication that inflammatory processes triggered by lung cancer may be responsible for pulmonary hypertension.
Lung cancer has long since taken on the character of an epidemic: the disease is already responsible for more than a quarter of all cancer deaths, and the trend is rising. One reason for this is that the prognosis is poor: only one-fifth of patients are still alive five years after diagnosis. This is partly due to the fact that lung cancer is often not recognized until it is in an advanced stage. Another problem is that a variety of different lung cancers exist, each of which requires its own therapeutic concept. This, in turn, requires a better understanding of the disease.
References:
- Soni Savai Pullamsetti, Baktybek Kojonazarov et al. Lung Cancer–Associated Pulmonary Hypertension: Role of Microenvironmental Inflammation Based on Tumor Cell–Immune Cell Cross-Talk, Science Translational Medicine DOI: 10.1126/scitranslmed.aai9048