Correlation of DNA content and histology in prognosis of astrocytomas

Thirty-two cases of astrocytoma were analyzed for DNA content and cell-cycle proliferation features by flow cytometry using paraffin-embedded tissue. The findings were correlated with histologic grading and survival. Abnormal DNA (aneuploidy or elevated G2-M fraction greater than or equal to 7%) was present in 18 cases (56%). Glioblastoma multiforme (GBM) had 11 of 16 (69%), anaplastic astrocytomas (ANA) 7 of 11 (64%), and low-grade (LG) neoplasms 0 of 5 cases with abnormal DNA content. Short-term survival (less than or equal to 26 months) occurred in all 16 patients with GBM (100%), 7 of 11 patients with ANA (64%), and 1 of 5 patients with LG neoplasms (20%). Seventeen of 18 patients (94%) with abnormal DNA content were short-term survivors (P less than 0.0002). Abnormal DNA content was found in 17 of 24 short-term survivors (71%), whereas histologic grading identified 16 of 24 such cases (67%). A combination of grading and abnormal DNA content identified 22 of 24 (92%) of the poor survival cases. DNA content was most useful in the anaplastic group. Six of seven cases (86%) with abnormal DNA content had short survival (P less than 0.055), and three of four (75%) with normal DNA content had long survival. DNA analysis combined with histologic grading improves prognosis designation.