Prognostic significance of nuclear deoxyribonucleic acid ploidy patterns in resected hepatic metastases from colorectal carcinoma.

Nuclear deoxyribonucleic acid (DNA) ploidy studies of paraffin-embedded archival tumor specimen blocks were performed by flow cytometry on extracted nuclei from 101 surgically resected hepatic metastases from colorectal cancer. In 28 patients, the corresponding primary carcinoma of the metastases was also studied. Tumor clinicopathology and clinical course of the patients were reviewed. Preparation of paraffin-embedded tissue specimens was performed by the technique of Hedley et al. and stained with propidium iodide according to the method of Vindelov et al. Eighty-eight of 101 metastatic tumors and 26 of 28 primary tumors yielded evaluable DNA histograms. Twenty-six metastases showed a DNA diploid pattern, 25 showed a significantly increased 4C peak (DNA tetraploid/polyploid), and 37 had a DNA aneuploid peak. Ploidy pattern was constant between primary and metastases in 84.6% of tumors. No significant relationship between host and tumor characteristics and ploidy pattern was found except for a correlation between grade 3 metastases and DNA aneuploid. Survival of patients with DNA aneuploid metastases was significantly less than that of patients with DNA diploid metastases (p = 0.03). However, among DNA nondiploid metastases, survival was significantly less for low DNA index metastases (less than or equal to 1.5) than for high DNA index (greater than 1.5) metastases (p less than 0.05). Flow cytometric DNA ploidy measurements may have prognostic value for patients with resected hepatic metastases from colorectal carcinoma.