Standardized AgNOR analysis in actinic keratosis

Area of Science:

• Dermatopathology
• Oncology
• Cell Biology

Background:

• Actinic keratosis (AK) is a common pre-malignant skin lesion.
• Predicting AK's progression to invasive squamous cell carcinoma (SCC) is clinically important.
• Silver-stained nucleolar organizer region (AgNOR) proteins are associated with cellular proliferation.

Purpose of the Study:

• To evaluate if the quantity of AgNOR proteins can predict the behavior of AK.
• To compare AgNOR quantities in AK, squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and normal skin.

Main Methods:

• Standardized AgNOR analysis was performed on 51 AK cases, 10 SCC, 10 BCC, and 10 normal skin samples.
• Formalin-fixed, paraffin-embedded sections were used.
• Mean area of AgNORs per nucleus (NORA) was quantified according to Committee on AgNOR Quantification guidelines (1995).

Main Results:

• Significant differences in NORA values were observed among normal skin (1.869 µm²), AK (3.988 µm²), BCC (3.044 µm²), and SCC (5.286 µm²).
• A progressive increase in mean NORA values was noted in AK from Stage I (3.161 µm²) to Stage IV (5.168 µm²).
• Highly significant differences (P < 0.001) were found between early and late stages of AK progression.

Conclusions:

• AgNOR quantity is a significant indicator of proliferative activity in AK.
• Increased AgNOR levels in AK correlate with a higher tendency to develop into invasive SCC.
• AgNOR analysis may aid in identifying high-risk AK lesions requiring closer monitoring or treatment.