The manifestation of proliferating cell nuclear antigen in adenoid cystic carcinoma

This study was conducted to evaluate the prognostic value of immunostaining with a genetically engineered monoclonal antibody (PC10) to proliferating cell nuclear antigen in patients with adenoid cystic carcinoma (ACC).

Formalin-fixed, paraffin-embedded tissue blocks from patients with ACC were stained with PC10, and an index (percentage of positively staining cells per tumor cells) was calculated. The patients' clinical course was compared with the PC10 index. Follow-up ranged from 12 to 177 months (mean, 64 months).

Patient selection and immunohistochemical studies were done at Seoul (Korea) National University Hospital.

Twenty-eight cases of ACC were retrieved from our files between January 1979 and December 1992.

All of the cases expressed the PC10 antibody. The PC10 index ranged from 1.0% to 44% (mean, 14.5%). We divided the 28 cases into two groups: group 1 (PC10 index, less than 15%) and group 2 (PC10 index, greater than 15%).

The PC10 index (groups 1 and 2) did not correlate with established pathologic grades, tumor staging, local recurrences, or survival rates. However, those with higher PC10 indexes (group 2) exhibited significantly increased distant metastases compared with those with lower indexes (group 1).

We conclude that the proliferating cell nuclear antigen in ACC may be used as an indicator in the prediction of distant metastasis.