Abstract:
Objective: Increased numbers of removed lymph nodes (LN) are resulting in more accurate staging
of the patient (Will-Rogers-Phenomenon). This study evaluates dependence of lymph node
sample size to 1) Will-Rogers-Phenomenom, 2) influence of sample size on overall survival and in
terms of 3) morbidity and mortality. Methods: 131 patients after pulmonary resection were retrospectively
analysed concerning surgery, number of removed lymph nodes, stage, complications
and survival. Patients were stratified according to the median number of lymph nodes in two
groups (A <12 lymph nodes and B ≥12 lymph nodes). Results: 5% of the patients had only local
lymphadenectomy and in 14% a systematic lymphadenectomy was performed. 17% of the patients
showed skip metastasis. Lymph node positivity was correlated to the number of removed
lymph nodes (p = 0.003). The approximated median survival for UICC (Union internationale contre
le cancer) stage I was 511, stage II 521 and stage III 290 days. Subgroup analysis of survival
data showed in group A an approximated median survival at stage I of 495 days, at II 537 days and
at III 451.5 days. Group B showed at stage I 675 days, at II 521 days and at III 221 days. There was
no difference in complications and mortality. Conclusion: A too low sample size leads to understaging
due to skip metastasis. Obligatory mediastinal lymph node sampling would decrease the
risk of understaging due to skip metastasis and does not increase morbidity or complications.
Lymph node sampling is not inferior concerning morbidity and survival in our patient collective.
This study cannot recommend a minimum number of LN to be resected. The evaluated limit of 12
LN proves to be suitable as a guideline.
