Interstitial fluid pressure predicts survival in patients with cervix cancer independent of clinical prognostic factors and tumor - Oxygen measurements

The purpose of this study was to determine the independent prognostic signi ficance of interstitial fluid pressure (IFP) measurements in cervix cancer. A total of 102 patients with newly diagnosed cervix cancer were accrued to this prospective study. There were 31 International Federation of Gynecolo gy and Obstetrics stage IB or IIA tumors, 40 IIB tumors, and 31 IIIB tumors . The median size was 5 cm (range, 2-10 cm). Pelvic lymphadenopathy was ide ntified radiographically in 20 patients. IFP was measured at examination un der anesthesia using a wick-in-needle technique. Multiple measurements were made in each tumor. The mean IFP in individual tumors ranged from -3 to 48 mm Hg, and the median for the entire cohort was 19 nim Hg. Treatment consi sted of external beam and intracavitary radiation without chemotherapy. Med ian follow-up was 2.5 years. The 3-year disease-free survival of all of the patients was 53%. Disease-free survival was 34% in patients with IFP >19 m m Hg, and 68% in those with lower IFP (P = 0.002). To evaluate rigorously t he independent prognostic significance of IFP measurements relative to esta blished clinical factors, a multivariate model was first developed using st epwise selection of clinical covariates. Tumor size (P = 0.0003) and pelvic lymph node status (P = 0.0016) comprised the clinical model. IFP, when add ed to this model, provided additional independent prognostic information (P = 0.0013). IFP was also significant (P = 0.0027) when the clinical factors and hypoxic proportion as determined with the Eppendorf electrode were ana lyzed together. Patients with high IFP were more likely to recur both local ly and at distant sites. This study is the first to document a strong, inde pendent prognostic importance of pretreatment IFP measurements in cervix ca ncer. Patients with high IFP are significantly more likely than those with low IFP to recur after radiotherapy and die of progressive disease, indepen dent of clinical prognostic factors and the results of tumor oxygen measure ments.