R. Taylor et M. Coates, BREAST-CANCER 5-YEAR SURVIVAL IN NEW-SOUTH-WALES WOMEN, 1972 TO 1991, Australian and New Zealand journal of public health, 21(2), 1997, pp. 199-205
This study of breast cancer survival is based on analysis of five-year
relative survival of 38 362 cases of invasive breast cancer in New So
uth Wales (NSW) women, incident between 1972 and 1991, with follow-up
to 1992, using data from the population-based NSW Central Cancer Regis
try. Survival was ascertained by matching the registry file of breast
cancers against NSW death certificates from 1972 to 1992, mainly by au
tomated probabilistic linkage. Absolute survival of cases was compared
with expected survival of age- and period-matched NSW women. Proporti
onal hazard regression analysis was used for examination of the effect
s on excess mortality of age, period of diagnosis and degree of spread
at diagnosis. Relative survival at five years increased from 70 per c
ent in 1972-1976 to 77 per cent in 1987-1991. Survival improved during
the 1970s and in the late 1980s. Regression analysis suggested that p
art of the improved survival in the late 1980s was due to lesser degre
e of spread at diagnosis, whereas the improved survival during the 197
0s may have been due to treatment. Survival was better for those aged
40-49 years (RR = 0.86) and worse for those aged greater than or equal
to 70 years (RR = 1.22) compared with the referent group (60-69 years
). Excess mortality was much less for those with invasive localised di
sease than those with regional spread (RR = 3.1) or metastatic cancer
(RR = 15.5) at diagnosis. For the most recent period (1987-1991), rela
tive five-year survival was 90, 70 and 18 per cent, respectively, for
the three degree-of-spread categories.