Scientists pave the way for lung cancer blood test
A molecule involved in tumour development is found in high concentrations in the blood of lung cancer patients, and could act as an early indicator of the disease, according to research published in the British Journal of Cancer1.
Testing for the molecule - called pleiotrophin - might also be useful for monitoring the success of treatment, since its levels seemed to be highest in patients with advanced cancer and lowest in those who had responded well to chemotherapy.
German researchers found that levels of pleiotrophin were 11 times higher in the blood of lung cancer patients than in healthy people, with 81 per cent of patients having raised concentrations of the molecule.
Scientists from the Phillipps University of Marburg in Germany took blood samples from 63 patients with small cell lung cancer and 22 with non-small cell lung cancer. They measured the levels of the pleiotrophin molecule and compared them with those of 41 healthy volunteers.
Only 1 of the 41 healthy people (2.4 per cent) had raised levels of pleiotrophin, compared with 87 per cent of the small cell lung cancer patients and 63 per cent of those with non-small cell lung cancer. The average concentration of the molecule was 11 times higher in the people with cancer.
Levels of pleiotrophin in the blood seemed to increase as the disease became more advanced. Scientists divided the patients into three groups, with early, intermediate and late stage cancer. Compared with the early stage group, levels of pleiotrophin were 37 per cent higher in the intermediate group and 62 per cent higher in the late stage cancers.
Team leader Dr Gerhard Zugmaier comments: "Lung cancer is often diagnosed much too late and a blood test that could detect early signs of the disease would be a real step forward.
"Our study suggests that the levels of pleiotrophin are substantially increased in lung cancer patients, particularly those with small cell lung cancer. If large-scale research confirms our results, then testing for the molecule could help in diagnosing the disease."
Dr Zugmaier and his colleagues also conducted a small additional study to see how levels of the molecule varied during a patient's treatment. Blood levels of pleiotrophin were monitored in seven lung cancer patients who were receiving chemotherapy.
In two patients who went into remission, the levels of pleiotrophin dropped, while in three who did not benefit from chemotherapy, they remained high. And in two further patients who initially responded, only to relapse, levels of pleiotrophin dipped, before returning to their initial level.
Commenting on these results, Dr Zugmaier says: "This part of the study was very preliminary, but it was certainly intriguing that the levels of the molecule seemed to correlate with the success, or otherwise, of treatment. It would undoubtedly be very useful for clinicians to have a quick and simple way of monitoring patients during a course of treatment."
Prof Gordon McVie, Joint Director General of Cancer Research UK, owners of the British Journal of Cancer, says: "Lung cancer has to be detected early to increase the chance of successful treatment. This research, while at an early stage, could be an important step towards a future diagnostic test."
Sir Paul Nurse, Joint Director General of Cancer Research UK, says: "This is an interesting study, which suggests that a molecule we think is involved in the growth and spread of tumours is detectable in the bloodstream of lung cancer patients."
- British Journal of Cancer86 (6)
Note to Editors:
There are around 39,000 cases of lung cancer each year in the UK. Around a quarter of these are small cell lung cancers, with the remainder being non-small cell.
Pleiotrophin promotes cell division and the growth of a tumour's blood supply, and seems to be important in cancer spread.
Levels of pleiotrophin are also raised in pancreatic and colon cancer.