Mammographically negative breast cancer at the Strathfield Breast Centre

The current diagnostic modalities used to detect breast cancer are mammography, together with clinical examination, ultrasound and fine needle aspiration biopsy (FNAB). The accuracy rates for each modality varies and a combination of the modalities is recommended to detect cancer early. Some authors have suggested that mammography should be used primarily as a screening tool because of the false negative mammography results that have been reported in the past 10 years. The records of patients at the Strathfield Breast Centre were reviewed to determine the accuracy of other modalities.

The records of 371 breast cancer patients treated at the Strathfield Breast Centre in the 6 years form 1989 to 1994 were reviewed to determine the accuracy of mammography, ultrasound, clinical examination and fine needle aspiration biopsy. Of the 371 women with histopathologically diagnosed breast cancer, 349 had mammography.

The accuracy rate of mammography in the present study was 91% with a false negative rate of 9%. It was found that there was no significant delay in treatment of breast cancer in mammogram-negative patients.

Mammographically negative breast cancer was found to be more common in younger women, to be similar in size to mammogram-positive cancer, to occur in all histological types and grades and was usually invasive rather than noninvasive. The rate of lymph node involvement was similar to the mammogram-positive group.