Recent studies published by a group of scientists at an Italian university suggest that the levels of a common growth factor may have an effect on the survival of post-surgery mesothelioma patients.
Mesothelioma is a cancer of the mesothelium – the thin lining that surrounds the lungs, heart, and other organs. Its only known cause is asbestos exposure, and the disease carries a poor prognosis. Malignant mesothelioma is a particularly devastating disease because it has an extremely long latency period; the disease often does not become symptomatic until decades after the initial exposure has taken place. By the time diagnosis is made, the cancer has reached a late stage and mesothelioma treatment is not particularly effective. Research into new methods and treatments is ongoing, as no completely effective remedy is yet known.
Placental growth factor (PlGF) is a protein which, as its name suggests, is normally found in very high levels in the cells of the developing placenta. It has also been implicated in the survival of malignant tumors, and was recently shown to be found in very high levels in mesothelioma cells.
PlGF is related to vascular endothelial growth factor (VEGF), which has been shown to encourage the growth of new blood vessels in the human body. Under the right circumstances, these new blood vessels can feed tumors that might otherwise starve if left alone. The motivation for research into VEGF and its related proteins is founded in the desire to arrest the progression of certain cancers by stopping the development of blood vessels, and slowing down the growth of a tumor that requires the new blood vessels to provide nutrients.
The most recent study found PlGF to be overexpressed in cancerous mesothelioma. Of 27 patients with mesothelioma, 41% had higher-than-normal levels of the protein; a significant difference from the 7% of patients with a benign version of the disease. Interestingly, as PlGF levels increased in mesothelioma patients, their survival time after invasive surgery decreased. Conversely, lower levels of the protein correlated with longer survival times.
This means that PlGF might be a good diagnostic tool to determine the prognosis of mesothelioma patients. A cure for mesothelioma is a long way off, but the protein might also present an avenue for the treatment of the disease.