Table 5 Cox regression analysis of predicting factors for freedom from metastasis in 749 patients with localized clear cell renal cell carcinoma

pT classification

< 0.001

0.048

(T1b vs. T1a)

4.10 (2.16–7.78)

0.001

0.155

(T2a vs. T1a)

8.65 (4.55–16.44)

< 0.001

0.949

(T2b vs. T1a)

19.22 (10.39–35.57)

< 0.001

0.651

Age(≥65 vs < 65)

1.06 (0.72–1.57)

0.769

0.614

Gender

0.90 (0.63–1.30)

0.587

Fuhrman grade

< 0.001

0.004

(II vs. I)

4.70 (2.66–8.33)

< 0.001

0.757

(III vs. I)

9.70 (5.35–17.57)

< 0.001

0.398

(IV vs. I)

28.03 (14.11–55.69)

< 0.001

0.013

Smoking history

1.39 (0.98–1.96)

0.065

Hypertension

1.10 (0.77–1.57)

0.609

Diabetes

1.14 (0.71–1.84)

0.593

tumor necrosis extent

0.986

0% < TN < 20% vs. TN = 0%

1.06 (0.54–2.10)

0.865

TN ≥ 20% vs. TN = 0%

1.00 (0.54–1.87)

0.993

Ki-67 index

0.266

0% < Ki-67 < 10%vs. Ki-67 = 0%

0.53 (0.25–1.14)

0.104

Ki-67 ≥ 10%vs. Ki-67 = 0%

0.94 (0.44–2.02)

0.875

Tumor volume group

< 0.001

<0.001

17cm³ ≤ V < 40 cm³ vs. V < 17 cm³

2.06 (0.98–4.35)

0.058

0.999

40cm³ ≤ V < 134 cm³ vs V < 17 cm³

6.45 (3.60–11.57)

0.001

0.009

V ≥ 134 cm³ vs V < 17 cm³

17.07 (9.91–29.42)

< 0.001

<0.001

BMI(≥25 vs < 25)

1.11 (0.78–1.60)

0.561

Sugical approach (open vs laparoscopic)

0.99 (0.70–1.41)

0.970

Surgical modality (partial vs radical nephrectomy)

1.05 (0.74–1.50)

0.772

Tumor location (left vs right kidney)

0.73 (0.52–1.04)

0.080