Lobular carcinoma in situ and invasive cancer: the contralateral breast controversy.

We determined if the risk of relapse is increased in patients with the concomitant diagnosis of lobular carcinoma in situ (LCIS) and an invasive cancer, suggesting the need for a more aggressive surgical approach. A retrospective chart review was conducted from the University of Michigan's Cancer Registry of patients with LCIS and a simultaneous invasive cancer and patients with invasive cancer only diagnosed between 1981 and 1997. The two groups were compared statistically with the following variables: age at diagnosis, tumor stage, histopathologic type of cancer, type of surgery, first line of treatment, relapse status with dates, site of relapse, and vital status. Statistically significant differences were found in the distribution of age (mean p = 0.0484 and median p = 0.0216), and histopathologic type of cancer (p < 0.0001). No significant difference was noted in the overall survival between the two groups (p = 0.511). There was also a significant difference in the relapse-free survival curves between the groups (p = 0.032). The risk of relapse was almost double (1.92) for the cancer-only patients relative to patients with LCIS as a histologic component of cancer. There was no significant increase in contralateral or ipsilateral breast recurrence for patients with LCIS and an invasive cancer compared to an invasive cancer alone. This lends support to the use of breast conservation therapy for invasive cancer patients with a histologic component of LCIS. The significant difference in the types of cancer may support the theory of genetic progression of LCIS to cancer, but clearly further data are required to prove this hypothesis.