A decade of breast cancer screening in The Netherlands: trends in the preoperative diagnosis of breast cancer.

PURPOSE: In a prospective, multi-institutional follow-up study we describe the trends in the preoperative pathologic confirmation of breast cancer of women who underwent breast cancer screening between 1995 and 2005.

METHODS: We included all women aged 50-75 years who underwent biennial screening mammography in the southern breast cancer screening region of the Netherlands between February 13, 1995 and December 22, 2004. Clinical data, breast imaging reports, biopsy results and breast surgery reports were collected of all women with a positive screening result. Follow-up lasted through the next biennial screening examination and was approximately two years for all referred women.

RESULTS: Of 258,900 mammographic screening examinations, 3,064 (1.2%) were positive screens. The majority of women (92%) were analyzed in four regional hospitals and workup yielded breast cancer in 1,332 women. From 1995 to 2005, the percentage of breast cancer cases that underwent percutaneous biopsy prior to surgery, increased from 42.4 to 100%. The proportion of cancers with a preoperative diagnosis of malignancy by percutaneous biopsy, increased from 27.1% in 1995 to 92.7% in 2004. Preoperative breast cancer confirmation by fine needle aspiration cytology (FNAC) gradually decreased from 91.3% to 14.5%, whereas preoperative confirmation by ultrasound guided core biopsy (USCB) or stereotactic core needle biopsy (SCNB) increased from 8.7% to 69.1% and from 0 to 17.4% respectively.

CONCLUSIONS: A preoperative diagnosis of breast cancer is currently obtained in more than 90% of breast cancer patients. The increase in preoperative breast cancer diagnosis through 1995-2004 is correlated with the introduction of SNCB and increased use of USCB at the expense of FNAC.