An international panel updated their standards on the diagnosis and treatment of breast cancer, as reported in the October 2006 issue of the Journal of the American College of Surgeons (JACS).
According to the American Cancer Society, invasive breast cancer will be diagnosed in 211,240 women and will cause more than 40,000 deaths in 2005. The updated statement reflects the conclusions of a panel of 23 expert surgeons, radiologists, pathologists, and oncologists based on their own research, clinical experiences, familiarity with the professional literature, and points of consensus reached through discussion at a conference. However, the panel cautions that their conclusions should not be considered inclusive of all appropriate treatments or exclusive of other treatments reasonably directed at achieving the same results or of interventions performed in the context of clinical trials.
The overall focus of the statement is that physicians should attempt to replace traditional, invasive procedures for diagnosing breast cancer with proven, less-invasive diagnostic methods, such as minimally invasive needle biopsies of the breasts and sentinel node biopsies.
Summary of Recommendations
Mammography is the only imaging modality that should be used routinely to screen women for breast cancer. However, MRI may be used to screen younger women with a high risk of breast cancer because of a strong family history or BRCA mutation. MRI findings should be combined with other imaging data or histologic results prior to surgical planning. Diagnostic ultrasonography can be helpful in characterizing known breast masses, as it is more sensitive than mammography in evaluating tumor size.
The panel agreed that minimally invasive breast biopsy is the optimal initial method for tissue acquisition for image-detected breast lesions, in large part because the determination of cancer prior to surgery improves outcomes of breast-conserving therapy. For microcalcifications without an obvious mass, the authors recommend vacuum-assisted devices with needle sizes of 11 gauge or larger. Fine- needle aspiration is suitable for lymph-node evaluation but less so for evaluation of breast lesions.
Biopsy specimens should be labeled by surgeons to preserve three-dimensional orientation. Radiography or ultrasonography of the surgical specimen can be useful in determining whether the target lesion was successfully removed. Two views should be used for specimen radiography.
Pathologic breast specimens should be evaluated using the Nottingham Combined Histologic Grade, which accounts for glandular differentiation, mitotic count, and nuclear grade. Ideally, these findings are combined with radiologic data at a treatment conference involving pathologists, radiologists, and surgeons.
Pathologists should read both prognostic size, determined by the extent of the largest invasive component of the tumor and helpful in predicting survival and distant metastasis, as well as the overall size of the breast tumor.
Intraoperative ultrasonography and bracketing localization wires can aid in defining the limits of resection in breast-conserving surgery, as can preoperative MRI and ultrasonography.
Sentinel lymph node biopsy is the preferred means of pathologic axillary nodal staging. However, patients should be made aware of the possibility of a false- negative result with such testing. When the sentinel lymph node reveals minimal involvement of 0.2 mm or smaller, complete axillary dissection is not necessarily indicated.
Regarding treatment of DCIS, adjunctive radiation therapy has been demonstrated to reduce rates of local failure but may not improve survival. Older age, smaller, widely excised DCIS, and low- or intermediate-grade histology mitigate against using radiation therapy following surgery for DCIS. The use of adjunctive tamoxifen for patients with DCIS is controversial, but it seems to be more helpful among patients with receptor-positive DCIS. Sentinel lymph node biopsy generally has no role in the staging of DCIS, but it should be performed in women receiving mastectomy for DCIS.
Hormonal therapy should be offered to all women with hormone-receptor-positive tumors, and the minimum period of treatment is 5 years. Patients receiving other chemotherapy should receive both an anthracycline and a taxane. However, chemotherapy in addition to hormonal therapy is less likely to provide an overall clinical benefit for women older than 60 years of age with hormone-receptor-positive tumors or for those older than the 70 years with any breast cancer.