Hyaluronan (hyaluronic acid) and hyaluronectin in the extracellular matrix of human breast carcinomas: Comparison between invasive and non‐invasive areas

We performed quantitative determination of the distribution of hyaluronan (hyaluronic acid, HA) and the HA‐binding protein, hyaluronectin (HN), 2 components of the extracellular matrix of tumor desmoplasia, within 71 human breast carcinomas. Results showed that HA and HN were more elevated in tumoral than in non‐tumoral adjacent tissue, and that the peripheral invasive area of tumors contained increased levels of HA and HN as compared with the central non‐invasive area (p < 10–3 and p < 10–5 respectively). HN and HA levels of 61 ductal carcinomas were related to the histological grade of tumors; no significant difference was found between grades for HA; HN was found to be significantly lower in grade III than in grade II tumors (p < 0.01). HA and HN rates were correlated in grade I and grade II tumors and were not correlated in grade III. Mean percentage of HA saturation level by HN for whole tumors was found to be less than 4%, indicating that HA is essentially free of proteins and could be used as a target for cancer diagnosis or therapy. © 1992 Wiley‐Liss, Inc.