Prognostic Factors in Renal Cell Carcinoma

Are Small Renal Tumors Harmless? Analysis of Histopathological Features According to Tumors 4 Cm or Less in Diameter

PURPOSE

Small renal tumors detected incidentally are considered to have less aggressive potential. This assumption is mainly based on the low tendency to increase in size on serial imaging studies, but histopathological parameters of progression in larger patient series are scant.

MATERIALS AND METHODS

We reviewed data of 287 tumor bearing kidneys in which solid tumors 4 cm or less in diameter were detected by cross-sectional imaging and subsequently removed surgically. Tumor size as documented by preoperative computerized tomography was correlated to histological diagnosis, and in cases of malignancy correlated to tumor type, pathological TNM stage and nuclear (Fuhrman) grade. With multifocal lesions the largest single tumor was considered the reference lesion but multifocality was also considered a separate parameter.

RESULTS

At a mean tumor diameter of 2.94 +/- 0.87 cm 65 (22.6%) tumors were 2 cm or less, 103 (35.9%) were 2.1 to 3.0 cm and 119 (41.5%) were 3.1 to 4 cm in diameter. A total of 56 (19.5%) tumors were benign with no correlation to tumor size (Pearson test p = 0.660). Renal cell cancer was found in 227 (79.1%) patients with 159 (70.0%) clear cell, 47 (20.7%) papillary, 11 (4.8%) chromophobe and 10 others with no correlation to tumor diameter. Of the kidneys 31 (13.6%) had multifocal renal cell carcinoma, with a significant correlation to larger tumor diameter (linear regression p = 0.048) and papillary renal cell carcinoma subtype (linear regression p = 0.018). Two (4.2%), 4 (5%) and 25 (25.5%) cases of renal cell carcinoma 2 cm or less, 2.1 to 3 cm and 3.1 to 4 cm in diameter had Fuhrman grade G3/4, respectively (Pearson p = 0.0007). Advanced stage (pT3a or greater) was documented in 2 (4.2%), 12 (14.9%) and 35 (35.7%) cases for the same categories, respectively (p = 0.0023). Whereas distant metastases were diagnosed in only 4 patients with renal cell carcinoma with tumors 3 cm or less, distant metastases were in 10 (8.4%) patients with tumors 3.1 to 4 cm (p = 0.045).

CONCLUSIONS

The aggressive potential of small renal cell carcinoma increases dramatically beyond a tumor diameter of 3 cm. Given the difficulty in measuring tumor diameters reliably with sequential imaging studies, the threshold for selecting patients for a surveillance strategy should be set well under this parameter.

[Survival prognostic factors valuation on a series of 202 patients with surgical treatment of renal cell carcinoma]

OBJECTIVES

To describe renal cell carcinoma prognostic factors and set up the relationship with survival rates in this neoplasm. Likewise we show epidemiologic, clinical, diagnosis and therapeutic facts.

MATERIAL AND METHOD

We review 202 patients underwent surgical treatment for renal cell carcinoma and the following features were recorded: gender, age and presenting symptoms, especially incidentally discovered tumors; tumor-related factors like TNM tumor stage, tumor grade and venous involvement: therapy-related recorded were surgical techniques and cytokine-based therapy.

RESULTS

60% of the patients showed organ-confined disease, 10% of patients with renal cell carcinoma presented with nodal positive disease and 7% with systemic metastases. 42% of patients presenting incidental tumor, with survival rates substantially better than that for symptomatic patients. 42% of patients with nodal positive disease presented systemic metastases at diagnosis, and 30% at surveillance. Systemic metastases presented a particularly poor prognosis for patients with renal cell carcinoma, with 12-months survival rates that 0%. Patients with cytokine-related therapy for metastatic disease presented 24-months survival rates that 20%.

CONCLUSIONS

Renal cell carcinoma remains a major source of mortality, basically at advanced disease (nodal positive disease or systemic disease), without a clear improvement of survival rates despite the newer therapy modalities.