BERKELEY, CA (UroToday.com) - In the United States, renal cancer represents respectively the 7th and 9th most common malignancy in men and in women, accounting for about 3% of cancer deaths. In this country, the National Cancer for Health Statistics Institute (NCHSI)[1] estimated that 57 760 new cases would be diagnosed and 12 980 deaths would occur in 2009. In 2002, the global estimate was 20 800 new cases and 10 200 deaths, accounting for about 1.9% of tumors in general. We have, in our national literature, a lack of data concerning the general characteristics of patients with renal malignancy, since the disease is not among the 10 most frequent tumor types annually reported by the Brazilian National Cancer Institute.[2] The current work aims to show, from a survey of factors relevant to disease, the profile of patients with this type of pathology at the Brazilian National Cancer Institute over the past six years.
Between 2004 and 2010, 227 consecutive patients, including 116 males (51%) and 111 females (49%), with renal cell carcinoma (RCC), were referred to our Institute and treated with curative intent by radical nephrectomy. Only histological subtype, tumor necrosis, lymph node involvement, and presence of metastasis proved to be independent predictive variables of disease-free survival on multivariate analysis (p = 0.011, 0.042, 0.025 and p < 0.0001, respectively, Table 1). Our disease-free survival rates after 5 years for patients with clear cell, chromophobe, and papillary type I and II RCC were 72.5%, 100%, 90%, and 70% respectively. The presence of a sarcomatoid component was significantly associated with death of our patients with disease-free survival rate of 21.7% after 35 months of follow-up (Figure1).
The presence of tumor necrosis, lymph nodal involvement, and distant metastasis were the most powerful prognostic factors for survival in our patients with RCC. The survival rate at 5 years was 82.5%, 71.6% and 62.5% for patients without tumor necrosis, with less than 50% tumor necrosis and more than 50% tumor necrosis, respectively (Figure 2).
The literature is scant and contradictory in relation to the value of retroperitoneal lymphadenectomy for staging site. When lymph nodes are positive, the prognosis is poor because these patients often have concomitant distant metastases. The benefit would be in non-metastatic resectable disease. The trouble is that patients with positive nodes and absence of metastases are a rare group. In these selected cases there would be a longer survival, however lymphadenectomy would be unnecessary in patients with node-negative disease. In our series, lymphadenectomy was performed in 130 of our patients of whom 22 had lymph node involvement. When lymph nodes were negative for malignancy, disease-free survival at 5 years was 80% while in patients with lymph node involvement, rate of disease-free survival dropped to 43.3%. In patients in whom we had no access to the lymph nodes because the lymphadenectomy was not carried out, the rate of disease-free survival reached 70% (Figure 3).
Regarding the presence of metastases, only 14% of patients who developed metastases were alive after 5 years (Figure 4). Several studies have identified various sites of metastatic disease to have prognostic significance; however, the number of involved sites appears to be a good surrogate for these individual sites. In multivariate analysis, the number of metastatic sites appears to be a strong independent prognostic factor.[3]
In conclusion, histological subtype, tumor necrosis, lymph node involvement, and presence of metastasis proved to be independent predictive variables of disease-free survival on multivariate analysis (p = 0.011, 0.042, 0.025 and p < 0.0001, respectively). Therefore, the presence and rate of tumor necrosis should always be informed by the pathologist, and lymphadenectomy should always be performed in all patients.
References:
- Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ: Cancer statistics, 2009. CA Cancer J Clin. 2009; 59: 225-49.
- Brasil. Ministério da Saúde. Instituto Nacional de Câncer. Estimativa 2010: incidência de câncer no Brasil. Instituto Nacional de Câncer. Rio de Janeiro, INCA, 2009; p. 98.
- Bukowski RM. Prognostic factors for survival in metastatic renal cell carcinoma: update 2008. Cancer. 2009; 115(10 Suppl): 2273-81.
Written by:
Antonio Augusto Ornellas, MD, PhD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Department of Urology
Brazilian National Cancer Institute and Mário Kröeff Hospital
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