Rudolf-Virchow-Preis 1996. Priesträgerrede. Detection of surfactant protein gene expression by reverse transcriptase-polymerase chain reaction (RT-PCR) identifies metastases and occult tumor spread of pulmonary adenocarcinomas.

A highly sensitive assay using RT-PCR and primers specific for surfactant protein A (SP-A), B (SP-B), C (SP-C) and D (SP-D) genes was applied to detect nodal metastases and occult tumor spread of pulmonary adenocarcinomas. Transcripts of a 367-bp long SP-B gene fragment were detected in all control lymph nodes and tonsils offering evidence of illegitimate transcription of the SP-B gene in cells of lymphatic tissue. SP-A, SP-C, and/or SP-D transcripts were detected in 30 (83.3%) of 36 lymph nodes with histologically identifiable metastases of pulmonary adenocarcinomas and in 10 (55.5%) of 18 lymph nodes that were tumor-free on histologic examination. These findings provide evidence of occult tumor spread in regionary lymph nodes which remains undetectable by conventional light microscopy but can be detected by RT-PCR. Gene expression of SP-A and SP-C was restricted to pulmonary adenocarcinomas but SP-D gene activity has been detected in pulmonary large cell carcinomas, one pulmonary adenosquamous carcinomas and in non-pulmonary adenocarcinomas as well.