Histologic associations and long-term cancer risk in columnar cell lesions of the breast: A retrospective cohort and a nested case-control study

BACKGROUND. Mammary columnar cell lesions with atypia have been receiving increased scrutiny in view of their association with atypical hyperplasia (AH) and carcinoma. However, the few retrospective outcome studies performed have failed to establish an increased risk for recurrence or carcinoma on long-term follow-up. METHODS. The authors evaluated the overall cancer risk for 1261 biopsies with columnar cell lesions (CCL) in 4569 women from the Nashville Breast Cohort who were biopsied between 1969 and 1988. On the basis of Schnitt and Vincent-Salomon's classification, they also classified 229 biopsies with CCL into 3 categories: without hyperplasia or atypia, with hyperplasia lacking atypia, and with atypia. By using a nested case-control design, they compared the risks of invasive cancer associated with these 3 categories. RESULTS. A 2- to 3-fold increase in the occurrence of AH in the presence of CCL versus in their absence (P < .005) was observed. Relative risk of invasive breast cancer for women with both AH and CCL compared with those with AH alone did not differ significantly (risk ratio [RR] = 1.55; P = .29). The presence of CCL alone was associated with a mild increase in the overall cancer risk (RR = 1.47; P = .05). In the nested case-control study, no significant risk difference was observed among the 3 categories of CCL. CONCLUSIONS. The authors observed a positive association between CCL and AH. The possibility that CCL by themselves significantly elevate breast cancer risk is not well supported. However, a finding of CCL on benign breast biopsy may indicate the presence of AH, a more worrisome lesion.