although not a diagnosis method for pulmonary neoplasms, are useful in monitoring the
response to treatment and the relapses, as follows: neuron specific enolase (NSE) increases
in micro-cellular neoplasm, Cyfra 21-1 increases in non-micro-cellular neoplasm, while the
increase of carcino-embryonic antigen (CEA) is non-specific, as it is high in both primary and
secondary lung cancer