Re: Breast cancer

I was concerned with some of the BCCA guidelines listed on page 199 (Breast cancer screening and diagnosis in British Columbia, BCMJ 2008;50:198-205). They are out of date, and do not include use of Breast Imaging Reporting and Data Systems (BIRADS) final assessment categories or current standards for further investigation and follow-up. 

I have since learned that the BCCA web site is in the process of being updated, but I am concerned that family physicians reading this article may start requesting the wrong tests, or insisting on unnecessary procedures.
The important changes to the original article are as follows:

• If there is an abnormality that is not clearly malignant but is new, further imaging with additional views, +/- magnification views, +/- ultrasound should be undertaken, based on the radiologist’s assessment.

• A new suspicious finding should be further assessed with imaging and a pathological diagnosis. A core biopsy done with either stereotactic or ultrasound guidance may be undertaken.

• If a mass is seen on mammography, ultrasound is appropriate. It can distinguish between a cyst and a solid lesion. There are also criteria to distinguish a benign from an indeterminate from a malignant lesion.

• If the lesion meets the criteria for a simple cyst, then aspiration is not required. If the lesion meets the criteria for a “complicated cyst” either aspiration or short interval (usually 6 months) ultrasound follow-up can be undertaken. If the lesion is symptomatic it can be aspirated. It is also reasonable to aspirate a cyst if necessary for mammographic/sonogra­phic correlation.

• If the lesion is solid, it is not always mandatory to proceed to biopsy. If it meets the imaging criteria for a “probably benign” lesion (positive predicative value for malignancy less than 2%), then short interval follow-up is preferable to biopsy. If the solid mass does not meet these criteria, then ultrasound-guided biopsy is appropriate. Fine needle aspiration biopsy (FNAB) has limited usefulness in image-guided breast bi­opsy. 

Unlike core biopsy, it cannot distinguish in-situ from invasive malignancy. Another reason core biopsies are preferred for suspicious lesions is that they also provide sufficient tissue for receptor analysis. Even for benign masses, core biopsy is more easily interpretable and therefore often yields more definitive diagnoses than FNAB. The appropriate use of FNAB is to rule out a complicated cyst, or to sample an axillary node suspicious for metastasis.

• When a lesion is visible both mammographically and sonographically, then ultrasound-guided intervention is generally preferable to stereotactic, unless the location of the lesion dictates that it would be safer to perform with stereotactic guidance. This is at the discretion of the radiologist.

• Any calcifications which do not meet the criteria for “probably be­nign” should be biopsied, usually stereotactically. “Sufficiently suspicious” is defined as a positive predictive value greater than 2%. Occasionally, suspicious calcification seen mammographically can be visible with ultrasound, but this is much less common.

—Paula Gordon, MD, FRCPC
Vancouver