Age, tumor size and relative survival of patients with localized renal cell carcinoma: a surveillance, epidemiology and end results analysis

Abstract

Purpose: Recent data demonstrate that age may be a significant independent prognostic variable following treatment for renal cell carcinoma. We analyzed data from the SEER (Surveillance, Epidemiology and End Results) database to evaluate the relative survival of patients treated surgically for localized renal cell carcinoma as related to tumor size and patient age.

Materials and methods: Patients in the SEER database with localized renal cell carcinoma were stratified into cohorts by age and tumor size. Three and 5-year relative survival, the ratio of observed survival in the cancer population to the expected survival of an age, sex and race matched cancer-free population, was calculated with SEER-Stat. Brown's method was used for hypothesis testing.

Results: A total of 8,578 patients with surgically treated, localized renal cell carcinoma were identified. While 3 and 5-year survival for patients with small (less than 4 cm) renal cell carcinoma was no different from that of matched cancer-free controls, patients treated for large (greater than 7 cm) localized renal cell carcinoma experienced decreased 5-year relative survival across all age groups. Therefore, age was not a significant predictor of relative survival for patients with small (less than 4 cm) or large (greater than 7 cm) tumors. However, a statistically significant trend toward lower relative survival with increasing age was demonstrated in patients with medium size tumors (4 to 7 cm). Hypothesis testing confirmed these findings.

Conclusions: These data suggest that relative survival is high in patients with tumors less than 4 cm and lower in patients with tumors larger than 7 cm regardless of age. However, increasing age may be related to worse outcomes in patients with tumors 4 to 7 cm. The cause of this observation warrants further investigation.

Figure 1

Relative survival (3 and 5-year) for localized RCC less than 4 cm by age group. RS rates represent comparison of observed survival in patients with small (less than 4 cm) tumors to expected survival for age, sex and race matched cancer-free population. Therefore, likelihood of 5-year survival for 38-year-old patient treated surgically for small (less than 4 cm) localized RCC is nearly identical to that of age, sex and race matched control without cancer (97.9%). Similarly elderly patients with small treated localized RCC have nearly identical survival compared to peers without cancer. Moreover, comparisons of RS rates among age cohorts revealed no statistically significant differences.

Figure 2

Relative survival (3 and 5-year) for localized RCC 4 to 7 cm by age group. RS rates represent comparison of observed survival in patients with medium (4 to 7 cm) tumors to expected survival for age, sex and race matched cancer-free population. Statistically significant differences (*) were identified in 3 and 5-year RS rates with increasing age. Therefore, 38-year-old treated surgically for medium size RCC has likelihood of 5-year survival more similar to that of cancer-free peers than does elderly patient (95.8% vs 85.8%).

Figure 3

Relative survival (3 and 5-year) for localized RCC greater than 7 cm by age group. RS rates represent comparison of observed survival in patients with large (greater than 7 cm) tumors to expected survival for age, sex and race matched cancer-free population. Therefore, likelihood of 5-year survival for 38-year-old patient treated surgically for large localized RCC is less than that of age, sex and race matched control without cancer (87.4%). Similarly elderly patients with large, surgically treated, localized RCC demonstrate reduced overall survival compared to peers without cancer. Comparisons of RS rates among age cohorts revealed no statistically significant differences, suggesting that large tumor size decreases relative survival equally across all age groups.