Risk of recurrence after surgical resection of small-sized invasive lung adenocarcinoma: analysis based on apoptotic index.
OBJECTIVE
It has been reported that small-sized invasive lung adenocarcinomas, i.e., those classified as type C through type F according to Noguchi's classification, may also recur even after complete resection. We evaluated the prognostic value of molecular biologic markers (apoptosis, Ki-67, p53, epidermal growth factor) and clinicopathological factors in patients with small-sized invasive lung adenocarcinomas.


METHODS
The clinical records of all patients who had had a peripheral adenocarcinoma surgically resected between 1996 and 2002, and histologically diagnosed as type C through type F according to Noguchi's classification were retrospectively reviewed. The apoptotic index (AI) was determined by the triphosphate biotin nick end-labeling method and the expression of Ki-67, aberrant p53 protein and epidermal growth factor receptor was determined by immunohistochemical staining.


RESULTS
Data from 28 patients who had been followed up for a mean period of 41.8 months (range: 16 to 89 months) were evaluated. During the follow-up period, recurrence was seen in 6 patients. The log-rank test showed that AI was a significant predictor of cancer recurrence. The 5-year disease-free survival rate of the 10 patients in the high AI group (AI > 0.3%) was 100%; while that of the 18 patients in the low AI group (AI < or = 0.3%) was 50.5% (p = 0.036). None of the other molecular biologic markers or clinicopathological factors were found to be a significant predictor of cancer recurrence.


CONCLUSIONS
Peripheral small-sized invasive lung adenocarcinomas with a low AI carry an increased risk of distant metastases, indicating that adjuvant chemotherapy after complete resection might be needed.
Morio
Atsushi
A
Department of General Thoracic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Miyamoto
Hideaki
H
Izumi
Hiroshi
H
D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D017209:Apoptosis; D015415:Biomarkers / Q000032:analysis; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D019394:Ki-67 Antigen / Q000032:analysis; D008175:Lung Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D012189:Retrospective Studies; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D015415:Biomarkers; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; D066246:ErbB Receptors