Determinants and prognostic implications of malignant ascites in metastatic papillary renal cancer

To describe the incidence of ascites in metastatic papillary renal cell cancer (pRCC), identify the factors associated with its development and evaluate its prognostic effect on the survival of these patients.

A retrospective evaluation of the medical records of patients with metastatic pRCC seen at National Cancer Institute (2000-2014) was undertaken. Logistic regression to identify predictors of the development of malignant ascites and Kaplan-Meier analysis to estimate survival was done.

Overall, 106 consecutive patients with metastatic pRCC were identified; sufficient data were available in 100 patients to enable assessment of ascites. Further, 20% had evidence of malignant ascites. Median age at diagnosis of ascites was 48.0 years (26.1-76.6 years) and median time to development of ascites from initial diagnosis of metastatic disease was 16.0 (0-73.3) months. There was no significant difference in the incidence of ascites between patients with hereditary and sporadic pRCC (P = 0.803) or among patients with different subtypes of pRCC (P = 0.456). Elevated platelet-lymphocyte ratio predicted development of malignant ascites in our cohort (P = 0.009). Median overall survival was shorter for patients who developed ascites [25.0 (10.2-39.8) months] compared with patients who did not develop this complication [42.5 (30.5-54.4) months, P = 0.041].

To our knowledge, this is the first systematic evaluation of the incidence, predictors, and prognostic effect of ascites in metastatic pRCC. Malignant ascites is a common manifestation of metastatic pRCC and is associated with a shorter overall survival. An elevated platelet-lymphocyte ratio predicts a higher risk of developing malignant ascites.