Lack of association between renal cell carcinoma and non-Hodgkin's lymphoma.

OBJECTIVES

To determine the incidence of non-Hodgkin's lymphoma (NHL) and renal cell carcinoma (RCC) after a diagnosis of the other malignancy.

METHODS

The 1973 to 1994 Surveillance, Epidemiology, and End Results (SEER) data base was used to determine the age-, sex-, race-, and calendar year-specific incidence rates for each year for RCC and NHL. The expected number of second cancers for each sex, race, and follow-up period (less than 1, 1 to 5, 5 to 10, and 10 or more years) was obtained by multiplying these incidence rates by the age-, sex-, race-, and calendar year-specific number of person-years at risk, with these products summed over the different age groups and calendar years. The standardized incidence ratio (SIR) was calculated (observed/expected number of second cancers), with statistical significance determined using the Poisson test.

RESULTS

From 1973 to 1994, 32,293 individuals in the SEER data base were diagnosed with RCC and 63,997 with NHL. NHL was diagnosed after RCC in 67 cases versus 59.8 expected (SIR 1.12, P = 0.19) and RCC after NHL in 96 cases versus 56.1 expected (SIR 1.71, P <0.0001). Only white males and females had a significantly increased risk of RCC after NHL, which was limited to the first year of follow-up. Excluding the first year of follow-up, NHL was diagnosed after RCC in 54 cases versus 49.3 expected (SIR 1.10, P = 0.27) and RCC after NHL in 54 cases versus 45.1 expected (SIR 1.20, P = 0.11).

CONCLUSIONS

When the first year of follow-up is excluded, there is no increased risk of NHL after RCC or vice versa.