Baseline perfusion CT parameters as potential biomarkers in predicting long-term prognosis of localized clear cell renal cell carcinoma.

PURPOSE

We aimed to explore the relationship among baseline perfusion CT parameters, clinical, and pathological factors with post-nephrectomy long-term progression-free survival in localized clear cell renal cell carcinoma.

MATERIALS AND METHODS

This study retrospectively collected 127 patients from March 2005 to May 2007 who undertook perfusion CT. 61 patients were confirmed of pT1N0M0 or pT2N0M0 ccRCC. The mean follow-up time is 118.8 months (± 13.1 m, range 72-135 m). We compared clinical, pathological factors (gender, T stage, age, Fuhrmann grade, VEGF level, and MVD), and perfusion parameters before treatment [blood flow (BF), blood volume, mean transition time, and permeability surface-area product] between groups with post-nephrectomy metastasis and without metastasis. Association between covariates and progression-free survival (PFS) were analyzed using Cox proportional regression.

RESULTS

Among 61 patients, 11 developed distant metastasis (10 in the lung, one in the bone). BF in metastatic group [429.1 (233.8, 570.1) ml/min/100 g] was significantly higher than non-metastatic group [214.3 (153.3, 376.5) ml/min/100 g] (p = 0.011). Metastatic group also had more patients with higher Fuhrmann grade. Multi-covariant Cox regression demonstrated T staging, Fuhrmann grade, and BF were significantly associated with PFS [hazard ratio (HR) 3.35, 3.08, and 1.006]. In another model, BF > 230 ml/min/100 g was associated with PFS (HR 12.90), along with T staging and Fuhrmann grade (HR 4.73, 3.69).

CONCLUSION

Baseline tumor BF is a potential biomarker in prediction long-term metastasis of localized ccRCC and may help screening for higher risk localized ccRCC patients who need personalized surveillance strategy after nephrectomy.