Objective: The purpose of this study was to compare invasive breast cancer in patients in their 40s with and without a family history of breast cancer as well as the lymph node meta-static rate and mastectomy rate.
Materials and methods: From 2000 to 2011, a total of 793,827 examinations were performed; 221,541 (28%) were women between 40 and 49 years old. A total of 6965 cancers were found in 6511 patients. Specifically, 1207 cancers (17.3%) were detected in 1162 patients in their 40s. Patients presenting for diagnostic evaluation and those with a personal history of breast cancer were excluded, leaving 388 cancers available for study; 238 (61%) cancers were in patients with no family history of breast cancer, and 150 (39%) were in patients with a family history of breast cancer. Pearson chi-square, Fisher exact, and Student t tests were used for between-group comparisons for qualitative data. A two-sided p value was reported for all tests.
Results: The difference in lesions detected by imaging was not statistically significant (p = 0.17); 65% (154/238) had invasive and 35% (84/238) noninvasive disease in the no family history of breast cancer group and 65% (98/150) and 35% (52/150), respectively, in the family history of breast cancer group (p = 0.90). The mastectomy rate was not statistically significantly different (p = 0.14). Fifteen percent (35/238) of the no family history of breast cancer patients and 12% (18/150) of the family history of breast cancer patients had positive lymph nodes (p = 0.45).
Conclusion: In patients in their 40s with or without a family history of breast cancer, no differences were detected in the proportion of invasive versus noninvasive cancers diagnosed, lymph node metastases, or mastectomy rates. Screening mammography should be performed in this age group regardless of family history.