[Comparative study for detecting micrometastases of lymph nodes in patients with lung cancer].
OBJECTIVE
To set up a new method to detect occult micrometastases of lymph nodes in patients with no-small-cell lung cancer (NSCLC).


METHODS
We had detected 195 lymph node samples taken from 25 patients with NSCLC during the operations. Each lymph node sample was divided into two same parts in size. The one half part of lymph node should be examined by conventional histopathologic examination and immunohistochemical (IHC) staining. All the remaining lymph node samples of each patient should be mixed together for the reverse transcriptase-polymerase chain reaction (RT-PCR) if they located in the same region. As long as the presence of metastatic tumor in one lymph node was found by H&E staining, all other lymph node samples in the same region should not be detected by IHC staining or RT-PCR techniques.


RESULTS
Frozen tissue sections of 135 lymph nodes that were staged as free of metastases by conventional histopathologic examination were screened by IHC staining. 31 lymph nodes showed single cell or cells clusters. Of 39 groups mixed regional lymph nodes which were diagnosed to be devoid of metastases by conventional histopathologic examination, 11 groups were found to have positive reactions to cytokeratin 19-mRNA by RT-PCR. There was a correlation between IHC staining and RT-PCR for detection of nodal micrometastases of NSCLC (U = 7.682, P = 0.0001).


CONCLUSIONS
IHC staining analysis can facilitate the detection of occult micrometastases in lymph nodes of NSCLC, and its assessment of nodal micrometastases can provide a refinement of TNM stage for partial patients with stage I to II. RT-PCR has the same value as IHC staining in detection of lymph nodal micrometastases. RT-PCR technique can reduce expense of the detecting micrometastases in lymph nodes.
Wang
Yun-Xi
YX
Department of Thoracic Surgery, General Hospital of the Chinese People's Liberation Army, Beijing 100853, China. wang_yunxi301@sina.com
Sun
Yu-E
YE
Li
Xiang-Hong
XH
Wang
Zhan-Bo
ZB
Liu
Yuan-Lin
YL
Chen
Liang-An
LA
Tong
Xin-Yuan
XY
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053539:Keratin-19 / Q000096:biosynthesis / Q000235:genetics; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction
D053539:Keratin-19