Intrapulmonary metastasis in resected pathologic stage IIIB non-small cell lung cancer: possible contribution of aerogenous metastasis to the favorable outcome.
OBJECTIVE
Non-small cell lung cancer with pulmonary metastasis in the primary lobe (PM+) is classified as pathologic stage IIIB. Although stage IIIB PM+ indicates a poor prognosis, this stage includes various subgroups with heterogeneous clinical outcomes. The objective of this study was to extract a subgroup of patients with stage IIIB PM+ non-small cell lung cancer with a better prognosis and assess their biological characteristics and metastatic mechanisms.


METHODS
We reviewed 122 cases of surgically resected stage IIIB PM+ non-small cell lung cancer and extracted a subgroup with a favorable outcome by univariate analysis of clinicopathologic factors. The 15 cases without lymph node metastasis and vessel invasion (PM+/N-/VI-) were extracted as the most favorable group. We assessed the clinicopathologic features of the PM+/N-/VI- group in comparison with the other patients with stage IIIB PM+ disease.


RESULTS
The disease-specific survival of the PM+/N-/VI- group was significantly better than that of the other stage IIIB PM+ group. Microscopic characteristics of the metastatic lesions suggesting that the cancer cells had invaded via the aerogenous route were seen in 86.7% of the PM+/N-/VI- group, as opposed to only 9.4% of the other PM+ cases. Furthermore, in all 4 patients in the PM+/N-/VI- group who had a recurrence, the relapse involved intrapulmonary metastasis, rather than distant organ metastasis.


CONCLUSIONS
Stage IIIB PM+ cases via the airway route were enriched in the PM+/N-/VI- group and had an extremely good survival. This group should be recognized as having local disease, and if relapse occurs in the remnant lobe, it may be possible to achieve a cure by local therapy.
Pathology Division, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Keiju
K
Aokage
Genichiro
G
Ishii
Kanji
K
Nagai
Osamu
O
Kawai
Yoichi
Y
Naito
Takahiro
T
Hasebe
Mitsuyo
M
Nishimura
Junji
J
Yoshida
Atsushi
A
Ochiai
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate