Radiologic tests after a new diagnosis of breast cancer.

CONTEXT: Radiologic tests may be overused in the staging of newly diagnosed breast cancer.
OBJECTIVE: To determine the frequency with which radiologic tests are used in women with newly diagnosed breast cancer and the yield of such tests in these patients.
METHODS: We used the tumor registry database from the Hoag Cancer Center, Newport Beach, California, to identify and classify the disease stage of all patients with breast cancer who received a diagnosis from or were initially treated by Hoag staff from 1990 to 1994. After excluding patients with unknown tumor (T) and lymph node (N) status, we retrospectively determined the frequency with which radiologic tests were performed within 4 weeks of diagnosis and the proportion of these tests that detected metastatic disease.
RESULTS: A total of 1910 radiologic tests, including 646 bone scans, 637 chest radiographs, and 627 other tests, were obtained in 1167 patients with a known TN status. Radiologic tests were performed in 42% of patients with carcinoma in situ, but none of the 183 tests detected metastases. Eight hundred twenty-eight radiologic tests were performed in patients who were classified as having stage I disease on the basis of TN criteria. Only three of these tests (0.4%) detected metastatic disease, and all three were performed in one patient with bone pain. For patients who were classified as having stage IIA, stage IIB, or stage III disease on the basis of TN criteria, 5 of 410 tests (1.2%), 20 of 294 tests (6.8%), and 33 of 195 tests (17%), respectively, yielded positive results.
CONCLUSIONS: Radiologic staging tests are overused in patients with newly diagnosed, early-stage breast cancer. These tests are unnecessary in patients with breast cancer who have 1) a tumor that is 5 cm in diameter or smaller, 2) no axillary lymphadenopathy on physical examination, 3) normal results on blood chemistry tests, and 4) no symptoms or physical findings of metastatic disease.