Tumor size and oxygenation are independent predictors of nodal disease in patients with cervix cancer

Purpose: To determine the relationships between tumor oxygenation and nodal stage in a prospective study of patients with cervix cancer, controlling f or other prognostic factors. Methods and Materials: Between 1994 and 1999, 128 eligible patients with ce rvix cancer were entered into a prospective study of tumor oxygenation asse ssed by Eppendorf oxygen electrode before primary radiation therapy. Oxygen ation was evaluated using the proportion of pO(2) values < 5 mmHg (HP5), an d tumors were classified as hypoxic if the HP5 was > 50%. Patients were ass igned to one of three groups: those with no imaging evidence of nodal (pelv ic or para-aortic) or distant metastatic disease (N group; n = 67), those w ith equivocal findings (E group; n = 28), and those with nodal or distant m etastatic disease (P group; n = 33). Results: The proportion of hypoxic tumors in the P, E, and N groups were 67 %, 50%, and 40%, respectively (p 0.014), with median HP5, values of 63%, 48 %, and 36%, respectively (p = 0.0024). In a multivariate analysis including tumor size, stage, HP5 and hemoglobin, it was found that tumor size and HP 5 were the only independently significant variables for the finding of meta static disease (p = 0.009 and 0.017, respectively). Conclusion: In this patient population, there was a significantly increased risk of nodal or distant metastases in patients with hypoxic tumors, and t his finding was independent of tumor size. These results are consistent wit h the hypothesis that tumor hypoxia is an adverse prognostic factor associa ted with selection for a metastatic phenotype. (C) 2001 Elsevier Science In c.