Preoperative diagnosis of carcinoma of the breast: Is a "cost-cutter" algorithm tenable?

BACKGROUND

Decision making in favor of conservative breast surgery is dependent upon the accuracy of preoperative evaluation of tumor stage, of which imaging modalities occupy a pivotal role. Systematic studies correlating the relative accuracy of various evaluating strategies are few, but remain vital means of making the optimal selection of diagnosis and subsequent treatment option. In this study, we evaluated the relative efficacy of: (1) palpation (P), (2) ultrasonography (US), and (3) bilateral mammography (MG) of the breast and axilla.

METHODS

In a prospective study, 109 female patients undergoing a modified radical mastectomy were subjected to a preoperative diagnostic assessment protocol involving palpation, ultrasonography, and bilateral mammography of the breast and axilla. Subsequently the preoperative findings were correlated to the postoperative histopathological reports. Cancer-specific criteria evaluated were tumor size, location, histologic type, histoarchitecture, and calcification, as well as status of regional nodes. Patient-specific criteria included age, size, and density of the breast and presence of associated benign breast disease. Percentage sensitivity, specificity, and positive and negative predictive values were determined for MG, US, and P as well as MG + P and US + P.

RESULTS

In assessment of the primary tumor, P, MG, and US showed an overall sensitivity of 88%, 92%, and 90%, respectively; MG + P and US + P had a sensitivity of 99% each. In nodal assessment, P, MG, and US showed an overall sensitivity of 88%, 69%, and 77%, respectively; MG + P and US + P had a sensitivity of 90% and 94%, respectively. Mammography understaged the tumor, whereas US and P overstaged tumors as well as nodes. US was particularly better than MG in younger women, smaller breast size, denser breast consistency, with or without associated benign breast disease, and cystic or necrotic tumors with invasive ductal histology. In addition, US was comparable to MG in most of the other criteria as well. Disadvantages of US over MG were its complete inability to detect microcalcification and certain intraductal cancers.

CONCLUSION

We conclude that: (1) the combination of US and P provides equivalent preoperative efficacy as MG, (2) the combination is more cost-effective preoperative assessment for subsequent selection of therapeutic modality, and (3) in certain well-defined circumstances discussed by us, mammography is most useful and should be considered as the imaging modality of choice.