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Pictogramme horloge November 2017

ProGRP has been available at Eurofins Biomnis since early October. It is the precursor of GRP, which is a neuropeptide identified in 1983 in SCLC but which has a half-life that is too short to allow it to be used as a marker.

Lung cancer (LC) is the fourth most common form of cancer, after prostate cancer, breast cancer and colorectal cancer. Its incidence is stable worldwide in men, but it has been increasing steadily in women since the 1980s. In 2012, average age at diagnosis was 67 years old in men and 66 years old in women, with net survival of diagnosed patients between 1989 and 2004 averaging out, in both sexes, at 43% at 1 year, 14% at 5 years and 9% at 10 years.

Almost all LCs are carcinomas (99%). They can be divided up into two major categories: NSC (Non-Small Cell) LCs, which are of epithelial origin and account for 80% of cases; and SC (Small Cell) LCs, which have neuroendocrine characteristics, making up the remaining 20%.

Various markers are already used regularly in follow-up of LC: Cyfra 21-1 and SCC, which may or may not be coupled with ACE for NSCLC, with NSE used for SCLC accompanied by Chromogranin A in some cases. More specifically, NSE and Cyfra 21-1 are used for a crucial differential diagnosis between NSCLC and SCLC, as they must be treated differently.

Nonetheless, these serum markers are not specific to the lung nor to the tumour process, meaning that it is essential to develop new markers, so as to improve the sensitivity and specificity linked to their use.

To this end, ProGRP has been available at Eurofins Biomnis since early October. It is the precursor of GRP, which is a neuropeptide identified in 1983 in SCLC but which has a half-life that is too short to allow it to be used as a marker.

By preference, ProGRP is used in LC:

  • In assisting with a primary diagnosis of SCLC

Its sensitivity and correlation with the histological type are better than that of NSE and its concentration is also correlated to tumour extension. However, the sensitivity of ProGRP can still be increased by between 14 and 23% according to studies in association with NSE.

The probability of having SCLC is 93% for a serum concentration of ProGRP in excess of 150 pg/ml.

  • In assisting with the differentiation of LC from other cancer pathologies

Concentrations of ProGRP are:

  • Less than 100 pg/ml in 96.4% of NSCLCs and 90% of neuroendocrine cancers;
  • More than 200 pg/ml in 60% of SCLCs but also 80% of medullary thyroid cancers.

 

  • In assisting with the differentiation between LC and a benign (non renal) disorder

Concentrations of ProGRP are less than 100 pg/ml in all cases, and even less than 50 pg/ml for 88.6% of lung diseases and 83.3% of other benign pathologies (liver, metabolic, autoimmune, inflammatory, etc.).

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