Infiltrating ductal carcinoma of the breast in South Australia. Implications of trends in tumour diameter, nodal status and case-survival rates for cancer control

The SA Central Cancer Registry gained sufficient information from routine pathology reports to record both the diameter and the nodal status for approximately half the infiltrating ductal carcinomas of the breast that were diagnosed in that State between 1980 and 1986. Of these, 27% of cancer had diameters of less than 2.0 cm at diagnosis and a similar proportion measured 4.0 cm or more. Almost half (48% of cancers) showed evidence of axillary nodal metastasis. Although the over-all variation in diameters by socioeconomic status did not approach statistical significance, lesions tended to be smaller in cases from the upper than the middle or lower socioeconomic areas of Adelaide. There also was evidence of earlier diagnosis during a breast self-examination campaign, but only a marginal increase in case-survival rates that readily was attributable to chance. A relatively poor case-survival rate applied in non-metropolitan areas, especially among older women, after adjusting for the available information on the stage of disease at diagnosis. A more limited access to treatment services may have been responsible. It will be important in a State-wide mammographic screening programme to provide for ready access by women in non-metropolitan areas to both screening and follow-up treatment services.