Routine mammography is associated with earlier stage disease and greater eligibility for breast conservation in breast carcinoma patients age 40 years and older

BACKGROUND. Reduction in breast carcinoma mortality is a major benefit of screening mammography and has been demonstrated in multiple randomized clinical trials and service screening programs. Another benefit from screening is that it allows the patient a wider choice of treatment options, particularly the possibility of conservation surgery. The current study analyzed the impact of mammography in the staging and treatment of breast carcinoma. METHODS. A total of 1591 women aged ≥ 40 years were treated for breast carcinoma between July 1995 and October 2001. Three subgroups were defined and compared. Group 1 had 192 patients with no previous mammography, Group 2 was comprised of 695 patients who underwent mammography on average less often than once yearly, and Group 3 was comprised of 704 patients who on average underwent mammography once yearly or more often. RESULTS. The difference in tumor stage was found to be statistically significant between the groups (P < 0.0001). In Group 1, 15% of the patients had ductal carcinoma in situ (DCIS) compared with 21% of patients in Group 2 and 26% of patients in Group 3. In addition, 32% of patients in Group 1 had T1 tumors, whereas 50% of patients in Group 2 and 56% of patients in Group 3 had T1 tumors. The tumor size was ≤ 1 cm in 8% of the patients in Group 1 compared with 20-23% of patients in Groups 2 and 3 (P = 0.0092). Breast conservation was an option for 41% of the patients in Group 1 but mastectomy was recommended in another 41% of patients. However, in Groups 2 and 3, 61% of patients were offered breast conservation and mastectomy was recommended to 28% (P < 0.0001). CONCLUSIONS. In the current study, women age ≥ 40 years with breast carcinoma who underwent mammography at least once yearly were diagnosed with DCIS more often compared with patients who underwent mammography less frequently or those who had no prior mammography. Women who underwent mammographic screening were found to have smaller tumors, which resulted in a majority of these patients being able to consider breast conservation as an alternative to mastectomy.