Time response of interstitial fluid pressure measurements in cervix cancer

Increased interstitial fluid pressure (IFP) is a common finding in malignant tumors as a result of the abnormal tumor vasculature and a lack of functional lymphatics. A recent clinical study by Milosevic et al. [Cancer Res. 61 (2001) 6400] reported a link between elevated IFP and survival in patients with cancer of the cervix. Patients with high IFP were more likely to have recurrence of tumors even after radiotherapy and were also more likely to die of progressive disease, independent of other prognostic factors. In this complementary study, using human data, we analyze 152 cervical tumor pressure IFP measurements from 42 patients with clinically diagnosed cancer of the cervix, randomly selected from the sample of 102 patients involved in the original study. We propose a simple biophysical model, based on flow through porous media, to explain the time response of the measured pressure curves in human cervical tumors. The response of IFP was governed by a time-constant tau(IFP) = 14 +/- 1 s averaged over multiple tumor sites. Interstitial hydraulic conductivity was computed to be approximately equal to 4.3 x 10(-6) cm(2)/mm Hgs.