Age at diagnosis, extent of disease and breast cancer survival: A population-based study in Florence, Italy

Background: The effect of age at diagnosis on the prognosis of breast cance r is still controversial. The study described the variation by age at diagn osis of some clinical-pathologic features and evaluated the relationship be tween age and survival, taking into account the effect of extent of disease . Materials: The study comprised a large population-based series of 1,182 inv asive breast cancers, incident in the period 1985-1986 in the province of F lorence, Results: The proportion of cases without nodal involvement progressively lo wered from 59% in the age group less than or equal to 39 years to 22% in th e age group greater than or equal to 80 years. The extent of disease was un known in 14% of cases aged 70-79 years end in 43% of those aged greater tha n or equal to 80 years (other age groups: 3%-5%). A lower rate of surgical treatment and axillary surgery were the main reasons for inadequate staging in the elderly. Ten-year observed survival progressively decreased from 71 % for age less than or equal to 39 years to 12% for age greater than or equ al to 80 years. Ten-year relative survival showed less evident differences, dropping from 72% for age less than or equal to 39 years to 51% for age gr eater than or equal to 80 years. In the relative survival analysis, the dif ferences in relative risks of death among age groups were not significant, either in the univariate or multivariate analysis. Nevertheless, the model with adjustment for extension of disease showed a flattening of the estimat ed relative risks in age groups over 59 years. Conclusions: Age at diagnosis was not significantly related to 10-year brea st cancer relative survival, suggesting that the worse prognosis in the eld erly was largely related to the risk of death from other causes, rather tha n to a different malignant potential of the tumor. The worse distribution b y extent of disease in older women indirectly suggested that diagnostic del ays also the different prognosis observed among age groups.