Autofluorescence (safe) bronchoscopy and p21/ki-67 immunostaining related to carcinogenesis

Archival biopsy materials from 20 randomly selected asymptomatic volunteers from the Czech uranium miners (CZ UM) risk group (n=98) were examined for p21 and ki-67 immunostatning. There were 16 areas with normal respiratory epithelium and 22 areas with bronchial intra-epithelial neoplasia (IEN). Normal and IEN areas were identified by autofluorescence (System Autofluorescence Endoscopy, SAFE-1000) and monitored during 1998-2002. The majority of specimens from areas with normal autofluorescence intensity with ciliated columnar bronchial epithelium showed strong predominantly cytoplasmic p21 positivity. The SAFE monitoring divided areas of decreased autofluorescence intensity with early stage IEN lesions into two groups. Persistent lesions (P)-showing a spectrum of p21 cytoplasmic staining ranging from negative or isolated negativity to weak or moderate positivity combined with higher proliferative capacity proved by ki-67 nuclear staining. Disappearing lesions (D)-showing strong cytoplasmic p21 positivity and negative ki-67 staining. The IEN lesions were classified into three groups based on p21/ki-67 immunostaining: proliferative lesions at risk (R) with low or without p21 plasma immunostaining combined with high ki-67 nuclear reactivity; ambiguous lesions (A) including cases combining strong p21 cytoplasmic positivity with high ki-67 nuclear reactivity or p21 cytoplasmic negativity with ki-67 negativity staining patterns; the quiescent lesion group (Q) was characterized by strong p21 cytoplasmic positivity and negative ki-67 immunostaining.