Staging lymph node metastases from lung cancer in the mediastinum

LinyaoThoracic surgery,unit one

Background

Lung cancer: 18% of all cancer death

Staging: TNM classification system based in 1958T:tumor sizeN:nodal diseaseM:metastasis

Current classification of the “N” component

N0: no lymph node metastasis N1: local peribronchial and/or ipsilateral

hilar

N2: ipsilateral mediastinal and/or subcarinal

N3:contralateral mediastinal and/or supraclavicular

evaluating N2 disease Imaging modalities

CT

PET

evaluating N2 disease Mediastinoscopy:“gold standard”

Lymph nodes stations 1, 2R, 2L, 3, 4R, 4L, and anterior station 7

morbidity 2%

mortality 0.08%

evaluating N2 disease ---invasive modalitiesEndobronchial ultrasound(EBUS)endoscopic ultrasound guided(EUS)

EBUS EUS

sensitivity 89% 89%

specificity 91% 100%

shortage both require high levels of expertise

evaluating N2 disease ---Intra-operative tchniquese

Lymph node dissection VS sampling

Debate:small sampling of relevant lymph nodes ?complete dissection of all visible lymph nodes ?

Conclusion: no difference

Moving towards molecular staging At present , use only T component

molecular staging with N componentCurrently unsuccessful

Advancing step: detect tumor DNA in N1 and N2 rather than intact cells

Prospect: more potent molecular marker technology

Sentinel lymph node staging Rely on lymphatic flow drainage patterns

Unsuccessful:large variability in lymphatic drainage among patients----“skipped metastases”

Conclusions Lung cancer :high morbidity and

mortality

Staging :TNM system(gold standard)

N2 disease:very heterogeneous require multiple investigating modalities

Prospects

Provide better prognostic value

Optimize treatment

Lead to fewer death

Thank you!