Renal cell cancer histological subtype distribution differs by race and sex

Objectives

To examine racial differences in the distribution of histological subtypes of renal cell carcinoma (
RCC
) and associations with established
RCC
risk factors by subtype.



Materials and Methods

Tumours from 1532 consecutive patients with
RCC
who underwent nephrectomy at
V
anderbilt
U
niversity
M
edical
C
enter (1998–2012) were classified as clear‐cell, papillary, chromophobe and other subtypes. In pairwise comparisons, we used multivariate logistic regression to estimate odds ratios (
ORs
) and 95% confidence intervals (
CIs
) for the associations between race, sex, age, end‐stage renal disease (
ESRD
) and body mass index at diagnosis according to histological subtype.



Results

The
RCC
subtype distribution was significantly different in black people from that in white people (
P
< 0.001), with a substantially higher proportion of patients with papillary
RCC
among black people than white people (35.7 vs 13.8%). In multivariate analyses, compared with clear‐cell
RCC
, people with papillary
RCC
were significantly more likely to be black (
OR
4.15; 95%
CI
2.64–6.52) and less likely to be female (
OR
0.60; 95%
CI
0.43–0.83). People with chromophobe
RCC
were significantly more likely to be female (
OR
2.32; 95%
CI
1.44–3.74). Both people with papillary
RCC
(
OR
6.26; 95%
CI
2.75–14.24) and those with chromophobe
RCC
(
OR
7.07; 95%
CI
2.13–23.46) were strongly and significantly more likely to have
ESRD
, compared with those with clear‐cell
RCC
.



Conclusion

We observed marked racial differences in the proportional subtype distribution of
RCCs
diagnosed at a large tertiary care academic centre. To our knowledge, no previous study has examined racial differences in the distribution of
RCC
histologies while adjusting for
ESRD
, which was the factor most strongly associated with papillary and chromophobe
RCC
compared with clear‐cell
RCC
.