Detection of contralateral breast cancer by mammography in women with previous breast cancer and the impact of endocrine therapy.

AIMS: To determine the efficacy and extent of screening mammography for detection of contralateral breast cancer in a cohort of women with previous unilateral mammary carcinoma, and to assess the effect of endocrine therapy on the risk of developing cancer in the contralateral breast. METHODS: Women with previous breast cancer eligible for mammography were identified from the Auckland breast cancer data file and the extent and outcome of mammographic screening determined by questionnaire and survey of mammography reports. The extent of adjuvant hormonal therapy and development of contralateral breast cancer was ascertained from the ABCDF records. RESULTS: Of 703 eligible subjects, 59% had undergone screening mammography with a cancer detection rate of 17 per 1000 mammograms and a benign to malignant ratio was 1.7 to 1. Contralateral breast cancer developed in 2.9% of 1980 women with previous unilateral mammary tumours who did not receive endocrine therapy with 1.1% of 374 women who were given adjuvant hormonal treatment (p = 0.04). CONCLUSIONS: The efficacy of mammography in those screened was comparable to major overseas screening programs, but the proportion of women undergoing mammography in this high risk group was relatively low suggesting a need for greater promotion of mammography in Auckland. The use of adjuvant endocrine therapy significantly reduced the rate of development of contralateral breast tumours supporting the current development of formal trials of chemoprevention of breast cancer in women at high risk groups of the disorder.

Mammographic screening for breast cancer: prospects for New Zealand.

The Cancer Society and the Department of Health invited a working group to make recommendations on screening by mammography. Mammography offers the best opportunity for preventing deaths from breast cancer. Randomised trials suggest that mortality can be reduced by about 30% in women over 50; the value of routine mammography in younger women is still uncertain. Apart from financial costs, the main drawback of mammography is that many women receive unnecessary investigation because of false-positive results. Careful design and monitoring of programmes is essential to ensure that the benefits of screening outweigh the disadvantages. In New Zealand there is a shortage of radiologists, pathologists, and clinicians who are skilled in the specialised techniques required for the screening of asymptomatic women. Decisions about routine screening should be delayed until pilot programmes have been established, with assessment of their effectiveness, economic efficiency, and social acceptability. Recommendations for the design of such programmes are made.

Obesity in a New Zealand community.

A retrospective analysis of the height, weight and certain biochemical data from the Rangiora Diabetic Survey is presented. In this survey 93 percent of the 2670 adult Europeans in Rangiora were studied. A high prevalence of obesity was found with 31 percent of the men and 46 percent of the women being greater than 20 percent above their ideal body weight. More than half the women aged 50 years and over were obese by the criteria used. The peak prevalence of obesity was in the seventh decade for women and in the eighth and ninth decades for men. There were significant increases in serum uric acid in obese men and women in each age decade. A surprise finding in the obese men was the increase in plasma protein levels but this did not occur in the obese women. Both men and women had a trend towards higher blood sugars when obese.