Tumour location and prognostic characteristics as determinants of survival of women with invasive breast cancer: South Australian hospital-based cancer registries, 1987-1998.

Survivals from breast cancer varied by location of lesion (P<0.001), with 10-year survivals of 61% applying for central (n=772), 73% for medial (n=350), and 72% for lateral (n=966) lesions. Univariate analyses of determinants of central locations indicated that the following were predictive: a more advanced TNM stage (P<0.001); a larger tumour diameter (P=0.002); a higher grade (P=0.032); a negative oestrogen receptor status (P=0.004); a negative progesterone receptor status (P=0.004); and histological type (P=0.011), with more of the lobular lesions being located centrally. Cox proportional hazards regression indicated that the relative risk (95% confidence limits) of case fatality for central, as opposed to other, lesions reduced from 1.46 (1.20, 1.78) to 1.16 (0.95, 1.41) when stage was added to the model, with no other factor having an additional conditioning effect. It is concluded that central lesions have worse outcomes, mostly due to their more advanced stages. Means of finding these tumours earlier should be investigated.