Prostaglandin in human breast cancer: Evidence suggesting that an elevated prostaglandin production is a marker of high metastatic potential for neoplastic cells.

Prostaglandin (PG) production by human breast cancers was investigated in 91 lesions selected so that the distribution of histologic type was similar to that of the general population of mammary carcinomas. With regard to the shape characteristics of the tumors, PG production was higher in lesions classified T1 and T2 than in lesions classified T3 and T4 (T-classification is based on extent of tumor as graded by the International Union Against Cancer), higher in tumors exhibiting a high cellularity than in lesions with a low tumor cell density and higher in tumors in which the cells were still adherent to each other. A high PG production was associated with the presence of neoplastic cells in tumor lymphatic and blood vessels and in axillary lymph nodes. PG production by node metastases was always higher than that by the primary tumor sites. The analysis of the stroma reaction and the presence of edema and necrosis suggest that an active PG synthesis occurred in lesions in which the tumor cell-surrounding stroma presented characteristics of low resistance to invasive growth of cancer cells. With regard to histologic differentiation and histoprognostic grade of lesions, PG production was elevated in carcinomas that retained a minute part of the acinoductal differentiation and in tumors with a moderate or high degree of cancer. A lesion containing a steroid receptor (SR) tended to produce less PG than did an SR-negative tumor. PG production increased slightly according to ages and times of menopause of the patients. PG production occurred early in the natural course of breast cancer and was elevated in tumors at a time when active tumor invasion proceeded. By contrast, PG production decreased later in the course of tumor development. These results indicated that elevated PG production can be used as a marker of high metastatic potential for neoplastic cells in breast cancer.