Lobular carcinoma in situ: observation without surgery as an appropriate therapy

The finding of lobular carcinoma in situ (LCIS) in the breast has generally prompted treatment with unilateral or bilateral mastectomy. Most experts now feel that LCIS simply identifies a woman who is at high risk to develop future breast cancer and requires only close clinical and mammographic follow-up. This approach has been recommended at our institution for > 15 years. This study defines the natural history of a population of women with LCIS who were treated by observation alone.

Women with a pathologic diagnosis of LCIS were identified by tumor registry search. Records and pathology were reviewed. Radiographic-pathologic correlation was performed on women who had undergone mammographic-localized breast biopsies. One hundred forty-nine women with LCIS were identified. Eighty four were excluded from analysis because of synchronous invasive cancer or ductal carcinoma in situ (DCIS). The remaining 65 women formed the basis of this report.

Sixty-five women with LCIS were treated from 1963 through 1990. Median follow-up was 83 months. No women were lost to follow-up. Median age at diagnosis was 48 years (range 37-81), and 32% had a family history of breast cancer. Clinical findings leading to biopsy were breast mass in 43, nipple discharge in three, and mammographic abnormality in 19. Mammographic-pathologic correlation showed that the focus of LCIS in these 19 women was not associated with the mammographic abnormality. Fourteen of 65 women underwent mastectomy after diagnosis of LCIS (nine ipsilateral, five bilateral). Fifty-one of 65 women elected observation alone. In the observation group, 13 of 51 women (25%) underwent a second breast biopsy for a clinical or mammographic abnormality during the follow-up period. The median interval to biopsy was 50 months. Pathology was benign in two, LCIS in seven, DCIS in one, and invasive cancer in three. All seven women with LCIS on subsequent biopsy continued with observation and none developed breast cancer. All four cancers were detected by mammography without an associated palpable mass. Three of four cancer masses were < 1 cm in diameter. The woman with DCIS was 47 years of age and developed DCIS 106 months after LCIS diagnosis. She was treated by total mastectomy and is disease free 108 months later. The three women with invasive cancer developed this at 41, 53, and 69 months after diagnosis of LCIS. All were < 50 years of age. All three cancers were in the same breast as the previous LCIS. Two women were treated by modified radical mastectomy, and the third had wide excision/axillary dissection followed by radiation therapy. They are alive and disease-free at 16, 82, and 116 months.

Four of 51 women treated with observation alone after diagnosis of LCIS developed breast cancer. All were detected by screening at an early stage. LCIS appeared to be an incidental finding on biopsy of mammographic abnormalities. The policy of observation alone for the finding of LCIS spares women mastectomy. Furthermore, cancers that develop in follow-up are likely to be detected at an early stage and be amenable to curative therapy. Observation alone is appropriate treatment for women with LCIS.