Impact of renal vein invasion and fat invasion in pT3a renal cell carcinoma

Abstract

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 signifi cantly 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 signifi cantly different outcomes. OBJECTIVE• 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. RESULTS• 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 signifi cant differences in disease-specifi c survival (DSS) were noted between FI only and RVI only groups ( P = 0.91). DSS was signifi cantly 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 signifi cantly lower in the group containing the parameters concurrently ( P = 0.009). Progression-free survival also was signifi cantly 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. CONCLUSION• 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 classifi cation because they have signifi cantly different outcomes. KEYWORDSkidney , renal carcinoma , prognosis , oncology Study Type -Therapy (case series) Level of Evidence 4

Stage T3a renal cell carcinoma: staging accuracy of CT for sinus fat, perinephric fat or renal vein invasion

“…Sinus fat invasion by locally advanced RCC has been the focus of many recent clinical outcome studies (6,(20)(21)(22)(23)(24)(25). It is recognized as a common sign of stage T3a RCC and 1-4).…”

“…signifies a poorer prognosis(6,20,21), hence its recent inclusion into the TNM classification. Yet, invasion of sinus fat has not been investigated in the radiological literature.…”

Obesity and renal cancer

“…This said, limited information is available on the variation in the risk of obese patients to develop RCC of different histological type, stage or grade, or stratified on other potential risk factors. However, it appears that clear cell RCC (ccRCC) is the histological subtype of RCC that is the most strongly associated with obesity, 6 , 7 and for which perinephric fat invasion is a significant predictor of poor disease outcome 8 . Paradoxically, obesity appears to be associated with an improved survival of cancer patients as well as with relatively poor symptomatic or local tumors, as it was documented recently by several studies.…”

Tumor size and Fuhrman grade further enhance the prognostic impact of perinephric fat invasion and renal vein extension in T3a staging of renal cell carcinoma

“…Tumors in the pT3a category, defined by anatomical extent, were distinctly excluded from these revisions, which were based on size criteria. Hence, the questionable difference in prognostic implications attributable to PFI in comparison with tumor size (pT1–2 tumors) remains controversial …”