Like ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS) is not classified as invasive breast cancer. In DCIS, the cancer cells have not spread beyond the duct walls to invade the surrounding tissue, whereas in LCIS the cells have not spread beyond the milk-producing glands (lobules) of the breast.
However, DCIS has greater potential to lead to invasive breast cancer than LCIS. If left untreated, at least a third of DCIS cases will progress to invasive breast cancer whereas approximately one-fifth of LCIS patients will eventually develop invasive breast cancer.
Also, while DCIS is a direct precursor to ductal breast cancer, women with LCIS can go on to develop lobular or ductal breast cancer and this may occur in the contralateral (opposite) breast, suggesting that LCIS is not a direct precursor to invasive breast cancer. In addition, this condition is rare—LCIS is found in fewer than 2% of all breast cancers. These factors have led to a great deal of variability in the management of LCIS, from increased surveillance to mastectomy. Now a new study has reported that recurrence rates for LCIS are significant, especially among women who are treated with lumpectomy without radiotherapy.
When does LCIS lead to invasive breast cancer?
While it is not possible to predict which LCIS patients will develop invasive breast cancer, there are some factors known to make it more likely. It is important that these variables be considered in deciding how to treat LCIS.
- Palpable LCIS. Note that LCIS that can be detected manually is more likely to feel like an area of thickening or firmness than a lump.
- High Ki-67 expression. Ki-67 is a marker of proliferation that normally can be found in breast cancer pathology reports.
- Pleomorphic LCIS. Such lesions should be removed surgically when diagnosed with a needle biopsy.
- Cigarette smoking is associated with increased risk of invasive breast cancer in women with LCIS.
Note that atypical lobular hyperplasia, which appears to be a precursor to both LCIS and invasive breast cancer, is more likely to progress to invasive breast cancer than LCIS.
Latest research finds LCIS is not always an indolent disease
The retrospective study referenced at the beginning of this news story was designed to investigate LCIS outcomes. The study included 200 women (median age 52) with pure LCIS who were treated in seven centers between 1990 and 2008. A total of 176 (88%) of the study participants underwent breast conserving surgery (typically, lumpectomy) and 24 (12%) had a mastectomy. Seventeen of the women received whole breast radiotherapy after breast conserving surgery. Fifteen of the women were also treated with tamoxifen and five received an aromatase inhibitor.
None of the 24 women who underwent a mastectomy experienced a local breast cancer recurrence (i.e., in the same breast, chest wall, or lymph nodes) during follow up. Three late local recurrences (i.e., after 10 years) occurred among the 17 women treated by breast conserving surgery plus whole breast irradiation. Among the 159 patients treated with breast conserving surgery without radiation, 20 (13%) experienced a local recurrence within 72 months and 17.5% experienced such a recurrence within 10 years. The authors were not able to identify specific risk factors associated with local recurrence.
Three of the 200 study participants developed distant metastases during follow up: two after first experiencing invasive local recurrence. A total of 22 (11%) of the women developed breast cancer in the contralateral breast—59% of these tumors were invasive. An additional five of the women were diagnosed with a second cancer during follow up. The authors conclude that LCIS is not always an indolent disease. The long-term outcome is quite similar to DCIS, according to the authors, who conclude that more accurate pathological definitions and clear identification of more aggressive subtypes are needed. Furthermore, breast conserving surgery plus whole breast irradiation makes sense in some selected cases, and the long-term results of such treatment appear comparable to DCIS.
Please see our article on lobular breast cancer and LCIS for more information.
Selected breast cancer studies
Synchronous lobular carcinoma in situ and invasive lobular cancer: Marker or precursor for invasive lobular carcinoma
Wallace A, Xiang D, Hockman L, Arya M, Jeffress J, Wang Z, et al. Synchronous lobular carcinoma in situ and invasive lobular cancer: Marker or precursor for invasive lobular carcinoma. European Journal of Surgical Oncology (EJSO). Elsevier BV; 2014; 40:1245-1249 10.1016/j.ejso.2014.04.007
Genetic Predisposition to In Situ and Invasive Lobular Carcinoma of the Breast
Sawyer E, Roylance R, Petridis C, Brook MN, Nowinski S, Papouli E, et al. Genetic Predisposition to In Situ and Invasive Lobular Carcinoma of the Breast. PLoS Genetics. Public Library of Science (PLoS); 2014; 10:e1004285 10.1371/journal.pgen.1004285
Evolving concepts in breast lobular neoplasia and invasive lobular carcinoma, and their impact on imaging methods
Oliveira TMG, Elias J, Melo AF, Teixeira SR, Filho SC, Gonçalves LM, et al. Evolving concepts in breast lobular neoplasia and invasive lobular carcinoma, and their impact on imaging methods. Insights into Imaging. Springer Science and Business Media LLC; 2014; 5:183-194 10.1007/s13244-014-0324-6
The Significance of Lobular Carcinoma In Situ and Atypical Lobular Hyperplasia of the Breast
Lewis JL, Lee DY, Tartter PI. The Significance of Lobular Carcinoma In Situ and Atypical Lobular Hyperplasia of the Breast. Annals of Surgical Oncology. Springer Science and Business Media LLC; 2012; 19:4124-4128 10.1245/s10434-012-2538-5
Clonal relatedness between lobular carcinoma in situ and synchronous malignant lesions
Andrade VP, Ostrovnaya I, Seshan VE, Morrogh M, Giri D, Olvera N, et al. Clonal relatedness between lobular carcinoma in situ and synchronous malignant lesions. Breast Cancer Research. Springer Science and Business Media LLC; 2012; 14 10.1186/bcr3222
High Ki67 expression is a risk marker of invasive relapse for classical lobular carcinoma in situ patients
Vincent-Salomon A, Hajage D, Rouquette A, Cédenot A, Gruel N, Alran S, et al. High Ki67 expression is a risk marker of invasive relapse for classical lobular carcinoma in situ patients. The Breast. Elsevier BV; 2012; 21:380-383 10.1016/j.breast.2012.03.005
The Diagnosis of Pleomorphic Lobular Carcinoma In Situ Warrants Complete Excision with Negative Margins
Middleton LP. The Diagnosis of Pleomorphic Lobular Carcinoma In Situ Warrants Complete Excision with Negative Margins. Current Breast Cancer Reports. Springer Science and Business Media LLC; 2012; 4:96-101 10.1007/s12609-012-0072-x
Surgical Outcome of Biopsy-Proven Lobular Neoplasia: Is There Any Difference Between Lobular Carcinoma In Situ and Atypical Lobular Hyperplasia?
Ibrahim N, Bessissow A, Lalonde L, Mesurolle B, Trop I, Lisbona A, et al. Surgical Outcome of Biopsy-Proven Lobular Neoplasia: Is There Any Difference Between Lobular Carcinoma In Situ and Atypical Lobular Hyperplasia?. American Journal of Roentgenology. American Roentgen Ray Society; 2012; 198:288-291 10.2214/ajr.11.7212