The value of dna flow cytometry and P53 as prognostic indicators in sebaceous gland carcinoma

Purpose. To evaluate the biologic behavior and prognosis of 21 cases of sebaceous gland carcinoma (SGC) using DNA flow cytometry and p53. Methods. Paraffin-embedded tissues from 21 SGC's were analyzed for DNA content (DNA index), the S-phase fraction (SPF), and p53 expression. The DNA index was reported as being either diploid or aneuploid, and the percentage of cells in the SPF was used to assess proliferative activity. Immunohistochemical stains for p53 were subjectively scored regarding staining intensity and percent of positive cells. These parameters were statistically correlated (Fisher exact test) with the clinical outcome Results. Of the 21 patients, twelve were alive at last follow-up, right have died of tumor and one died of unrelated causes. Fifteen tumors were diploid and six showed aneuploid DNA stemlines (28.6%) The SPF was analyzed in all tumors (range 2 l%-48.7%; median 21.5%) Of the twelve patients whose tumors expressed p53, 10 were reported to be alive and well, one died of métastases, and one died of unrelated causes. Seven of eight patients who died of metastatic disease did not express p53 in their invasive tumors (p value 0.0008). Conclusions. Our study strongly suggests that lack of expression of p53 in SGC is an ominous prognostic indicator DNA ploidy and SPF did not significantly predict the biologic behavior of these 2] tumors.