Staging of breast cancer: What standards should be used in research and clinical practice?

Background. Bone scan (BS), chest X-rays (CXR), liver ultrasonography (LUS) and laboratory parameters (LP) are frequently used as routine staging procedures for breast cancer patients. These procedures are not always appropriate in either clinical or research settings, regardless of the stage. The aim of this study was to identify groups of patients with differing risks for metastases in order to select more precise standard staging procedures. Patients ann methods: The staging data relating to 406 breast cancer patients consecutively referred to our institution between November 1989 and October 1996 were analysed including pathological TNN grading and biological parameters. All of the cases with a positive or suspicious pre-operatory staging and who proved to have metastatic disease before surgery or during the first six months of follow-up were considered true- positive; all of the other cases with a positive or suspicious initial staging but with no evidence of distant metastasis before surgery and with a disease-free survival longer then six months were considered false-positive. In the same way all cases with negative initial staging who relapsed during the first six months of follow-up were considered false-negative and those with negative initial staging and with a disease-free survival longer then six months were considered true-negative. Statistical analysis was performed using Fisher's exact test. Results: BS, CXR and LUS, 388, 399 and 398 examinations respectively, were considered available, and 17 (4.38%), six (1.5%) and four (1%), respectively, proved to be true-positive. A statistically significant difference was observed when our cases were grouped according to T status (T-4 vs. T-1-T-2-T-3, P < 0.01) and nodal status (N-0-N-1 cases with less than three involved nodes and N-1 with more than three positive lymph nodes N-2 patients, P < 0.01). Conclusions. The present study suggests that breast cancer patients can be divided into three subgroups with different detection rates for distant metastases at staging (0.59%, 2.94% and 15.53%), and that the standard practice should be changed. In the first (T1N0 and T1N1 patients with less than or equal to 3 positive lymph nodes - 41.13% of the patients) and the second group (T2N0, T2N1 with less than or equal to 3 positive lymph nodes, T3N0 and T3N1 patients with less than or equal to 3 positive lymph nodes -33.49% of the patients) there is no need for a complete set of staging procedures, whereas full procedural staging is needed in the third group of patients (T-4, N-1 with >3 lymph nodes and N-2, 25.37% of the patients).