Study Type – Therapy (case series)
Level of Evidence 4
What's known on the subject? and What does the study add?
The presence of invasion of renal vein and perinephric fat are predictors of poor outcome in patients with RCC. The latest version of the TNM system included tumours exhibiting such parameters in the T3a stage, thus grouping tumours with distinct pathologic features.
Our study showed that patients with RCC presenting concomitant invasion of the renal vein invasion and perinephric fat invasion have significantly worse survival rates than those showing any of the parameters separately. Therefore, we conclude that these tumours should not be grouped within T3a stage since they have significantly different outcomes.
• To evaluate the prognostic impact of tumor fat invasion (FI) and renal vein invasion (RVI) in patients with T3a renal cell carcinoma.
PATIENTS AND METHODS
• In total, 220 consecutive patients treated for renal cell carcinoma between 1992 and 2009 were analyzed. T3a stage cases were selected.
• A single pathologist reviewed all cases.
• The present study cohort included 46 patients with mean follow-up of 28.6 months, of whom 17 (36.9%) died from disease. Patients were initially divided into three groups including 24 (52.1%) of FI only, 11 (23.9%) of RVI only and 11 (23.9%) of both FI and RVI.
• In univariate analysis, no significant differences in disease-specific survival (DSS) were noted between FI only and RVI only groups (P= 0.91). DSS was significantly worse in the FI + RVI group compared to the other groups (P= 0.02).
• When grouped into FI or RVI vs FI + RVI, DSS remained significantly lower in the group containing the parameters concurrently (P= 0.009). Progression-free survival also was significantly lower in FI + RVI group (P= 0.01).
• Metastasis, positive lymph nodes and the presence of FI + RVI remained as isolated predictors of survival.
• Patients with FI + RVI presented a 2.6-fold increase in risk of death from cancer and a 2.5-fold increase in risk of disease progression (P= 0.04) compared to those with either of them alone.
• The isolated or concomitant presence of FI and RVI may be used as one of the criteria for staging in the next edition of the Tumour-Node-Metastasis classification because they have significantly different outcomes.