Purpose: To evaluate the significance of apoptotic index [Al) as a prognost
ic factor after surgery for nonsmall-cell lung cancer (NSCLC).
Patients and Methods: A total of 236 patients who underwent surgery for pre
viously untreated pathologic stage I to IIIa NSCLC between 1985 and 1990 we
re reviewed. Al was defined as the number of apoptotic cells, detected by t
erminal deaxynucleotidyl transferase-mediated deoxyuridine triphosphate-bio
tin nick end-labeling, per 1,000 tumor cells. Proliferative index (PI) and
aberrant p53 expression were also evaluated immunohistochemically.
Results: The 5-year survival rate for the lowest-Al group (Al < 5.0) was 74
.7%; those for the lower-Al group (5.0 less than or equal to Al < 11.0) and
the higher-Al group(11.0 less than or equal to Al < 25.0) were 51.6% and 5
7.8%, respectively These survival rates were significantly lower than that
of the lowest-Al group (P = .021 and P = .043, respectively). The highest-A
l group (25.0 less than or equal to Al), however, showed the most favorable
prognosis, with a 5-year survival rate of 83.2%. Multivariate analysis con
firmed that a moderate Al (5.0 less than or equal to Al < 11.0 or 11.0 less
than or equal to Al < 25.0) was a significant factor to predict poor progn
osis. The pls for the lowest-, the lower-, the higher-, and the highest-Al
groups were 32.3%, 48.0%, 54.3%, and 50.7%, respectively. The lowest-Al gro
up showed a favorable prognosis because of its low PI, whereas the lower- a
nd the higher-Al groups had a poor prognosis caused by increased cancer-cel
l proliferation. The highest-Al group showed the most favorable prognosis b
ecause apoptotic cell death overcame cell proliferation. No significant cor
relation was observed between Al and aberrant p53 expression.
Conclusion: Al proved to be an independent prognostic factor in NSCLC. a 19
99 by American Society of Clinical Oncology.