Analysis of Ki-67 immunoreactivity in recurring and nonrecurring nasal polyps.

OBJECTIVE

Nasal polyps are common, abnormal lesions. Recurrence of the nasal polyposis is prevalent and a severe problem. The aim of this study was to investigate the relationship between Ki-67 immunoreactivity and the risk of recurrence of nasal polyps. Ki-67 staining of polypectomy material was tested as a risk factor for recurrence independent of etiologic factors or treatment modalities.

DESIGN

Retrospective study.

SETTING

University hospital.

MAIN OUTCOME MEASURE: Ki-67 immunoreactivity.

METHODS

Pathologic specimens from patients with nonrecurrent and recurrent nasal polyps archived at the Department of Pathology were reviewed, and the most suitable blocks were chosen among the excision materials. Ki-67 antibody staining was investigated immunohistochemically using the avidin-biotin-peroxidase method. The percentages of nuclei immunostained for Ki-67 of at least 1000 epithelial cells in the most intensive staining areas at final magnification (x400) were calculated and defined as the labeling index. The Mann-Whitney U-test was used to compare the Ki-67 labeling index in the nonrecurring and recurring nasal polyp groups.

RESULTS

The mean Ki-67 labeling index was 1.4 +/- 1.972 (range 1-87 in 1000 epithelial cells) in the nonrecurrent nasal polyp group and 17.8 +/- 5.67 (range 82-446 in 1000 epithelial cells) in the recurrent nasal polyp group; the difference between the nonrecurrent and the recurrent group was significant (p < .01).

CONCLUSION

The results of this study clearly demonstrate that proliferative activity in the surface epithelial cells of recurring nasal polyps is significantly higher than that in nonrecurring nasal polyps.