Interstitial Hypertension in Human Breast and Colorectal Tumors1

The efficacy of present day antineoplastic regimens depends upon the delivery and penetration of therapeutic agents through the tumor vas cular and interstitial spaces to the tumor cell target. The distribution of relevant molecules or cells in a solid tumor is often poor and heteroge neous and is believed to be due to a number of pathophysiological factors, including elevated interstitial fluid pressure (IFF). Using the wkk-in-nmlKtechnique, IFF was measured in primary breast and colorectal carcinomas as well as their respective métastasesto the lymph nodes and liver in a total of 17 patients. IFF was also measured in one recurrent renal cell carcinoma, one melanoma metastasis to the lymph nodes, and another melanoma metastasis to the lung. IFF varied from 4 to 50 mm Hg with a mean ±SD of 20 ±13 mm Hg in the neoplasms (n = 41 measurements; n = 21 tumors), while IFF in normal tissues had a mean of 2 ±4 mm Hg (n = 11). The mean IFFs for metastatic melanoma, primary breast carcinoma, and liver métastases from a colorectal primary were found to be 33 ±14, 15 ±9, and 21 ±12 mm Hg, respectively. In the renal cell carcinoma, the pressure was 38 mm Hg. These results agree with the findings of our 3 previous studies examining IFF in human superficial melanomas (14.3 ±12.5 mm Hg, n = 12), cervical carcinomas (15.7 ±5.7 mm Hg, n = 12), and head and neck tumors (13.2 ±8.8 mm Hg, n = 19), and indicate that in all types of human tumors studied to date, IFF was significantly elevated above that of normal tissue. This observation may be useful in localizing tumors during needle biopsy.