M. Mccredie et al., 2ND PRIMARY CANCERS FOLLOWING CANCERS OF THE KIDNEY AND PROSTATE IN NEW-SOUTH-WALES (AUSTRALIA), 1972-91, CCC. Cancer causes & control, 7(3), 1996, pp. 337-344
Data from the New South Wales (NSW) (Australia) Central Cancer Registr
y for the period 1972-91 were examined to determine the risk of second
primary cancers following an initial invasive cancer of the renal par
enchyma (ICD-9 code 189.0), renal pelvis (code 189.1), or prostate (co
de 185). Eligible cases were restricted to those who had survived for
at least two months after diagnosis of the first primary cancer. Expec
ted numbers of cancers were obtained by assuming that subjects experie
nced the same cancer incidence as prevailed in the corresponding gener
al population and applying gender-, age-, and calendar-specific rates
to the appropriate person-years at risk. The relative risk (RR) of a s
econd primary cancer was taken to be the ratio of observed to expected
numbers of second cancers. Following prostatic cancer, there was an o
verall deficit of cancers at all sites combined (RR = 0.79, 95 percent
confidence interval [CI] = 0.75-0.84), and no site had a significantl
y raised RR. Taking this into consideration, there appeared to be a re
ciprocal relationship of increased risk of prostatic cancer (RR = 1.7,
CI = 1.2-2.3) following an initial cancer of the renal parenchyma and
of renal parenchymal cancer (RR = 1.2, CI = 0.8-1.7) after cancer of
the prostate. An increased risk of bladder cancer occurred following r
enal parenchymal (RR = 3.4, CI = 1.1-8.0, for women only) as well as a
fter renal pelvic cancer (men: RR = 8.7, CI = 5.4-13; women: RR = 39,
CI = 26-56). A tobacco-related pattern of excess risk was seen after r
enal pelvic cancer but not after cancer of the renal parenchyma. These
data illustrate that an excess of second primary cancers may reflect
shared etiologic factors or increased medical surveillance.