Risk of Infiltrating Breast Cancer Subsequent to Lobular Carcinoma in Situ

Lobular neoplasia occult on conventional imaging and diagnosed on MRI-guided biopsy: can we estimate upgrade on surgical pathology?

PURPOSE

The goal of this study is to evaluate the frequency and imaging features of lobular neoplasia (LN) diagnosed on MRI-guided biopsy, determine the upgrade rate to malignancy, and assess for any features that may be associated with an upgrade on surgical excision.

MATERIALS AND METHODS

Research ethical board approved the review of consecutive patients with MRI-detected LN between January 2009 and December 2018 with differentiation between pure LN and LN with associated other high-risk lesions. The final outcome was determined by final pathology results from surgical excision or 24 months of follow-up. Appropriate statistical tests were used.

RESULTS

Out of 1250 MRI-guided biopsies performed, 76 lesions (6%) fulfilled the inclusion criteria and formed the study cohort. Of the 76 lesions, 54 (71%) were pure LN while the rest had coexistent high-risk lesion. Non-mass enhancement (NME) was the most common lesion type (62, 82%). Fifty-nine lesions (78%) were surgically excised, the other 17 had benign follow-up. Overall, 8 lesions (11%) were upgraded to malignancy on final pathology. Malignant outcome was associated with larger lesion size (5.5 versus 1.9 cm, P < 0.001) and a clumped NME pattern (75% versus 24%, P = 0.006). Lesion size and clumped NME remained significantly associated with upgrade on sub-analysis of the pure LN group.

CONCLUSION

Larger lesion size and clumped NME are imaging findings associated with upgrade of LN diagnosed by MRI-guided biopsy. This may influence patient management in this clinical setting. Additional larger studies are needed to consolidate our results and to potentially detect additional factors associated with upgrade.

Most lobular carcinoma in situ and atypical lobular hyperplasia diagnosed on core needle biopsy can be managed clinically with radiologic follow-up in a multidisciplinary setting

We evaluated the efficacy of using standard radiologic and histologic criteria to guide the follow-up of patients with lobular carcinoma in situ (LCIS), lobular neoplasia (LN), or atypical lobular hyperplasia (ALH). Patients with high-risk benign lesions diagnosed on biopsy were presented and reviewed in a multidisciplinary clinical management conference from 1 November 2003 through September 2011. Associations between patient characteristics and rates of upgrade were determined by univariate and multivariate logistic models, and times to diagnosis carcinoma were calculated. Of 853 cases reviewed, 124 (14.5%) were lobular neoplasms. In all, 104 patients were clinically and/or radiographically monitored. In 20 patients, who were found to have LN on core biopsy and were recommended to have immediate surgical excision, a more significant lesion was identified in 8 (40%) of the excised specimens. Factors associated with a more significant lesion on excisional biopsy included whether the lobular lesion had been targeted for biopsy and whether the extent of disease involved three or more terminal duct lobular units. Of the 104 patients radiographically and clinically monitored, the median follow-up time was 3.4 years with a range of 0.44–8.6 years. Five patients under surveillance were subsequently diagnosed with breast malignancy (three of the five at a site unrelated to the initial biopsy). Patients with incidental lobular lesions identified on percutaneous core needle biopsy have a small risk of upgrade and may not require an excisional biopsy. Clinical management of low-volume lobular lesions in a multidisciplinary setting is an efficacious alternative to surgical excision when radiologic and histologic characteristics are well-defined.

Loss of heterozygosity in lobular carcinoma in situ of the breast

Aims-(1) To investigate whether loss of heterozygosity identified at various loci in invasive breast carcinoma or is present in lobular carcinoma in situ (LCIS). (2) To investigate whether LCIS is a monoclonal (neoplastic) or a polyclonal (hyperplastic) proliferation.Methods-Forty three cases of LCIS (30 with associated invasive carcinoma or in situ ductal carcinoma (DCIS) and 13 cases of pure LCIS) were investigated for loss of heterozygosity on chromosomes 16q, 17q, 17p, and 13q using a microdissection technique, polymorphic DNA markers, and the polymerase chain reaction (PCR).Results-Loss of heterozygosity was detected in both subgroups of LCIS at all the loci examined. There was no significant difference in the frequency of the loss between the group associated with invasive carcinoma and the pure LCIS group. The frequency of loss of heterozygosity ranged from 8% on 17p to 50% on 17q.Conclusions-Because of the nature of the technique employed, our findings show that LCIS is a monoclonal (neoplastic) proliferation rather than a hyperplastic proliferation. The incidence of loss of heterozygosity on 17p (D17S796) is lower than we have observed previously in DCIS, suggesting that LCIS and DCIS are different genetically as well as clinically and morphologically. The similar incidence of loss of heterozygosity on 16q and 17q, however, suggests that DCIS and LCIS may share a common pathway of evolution.

[Lobular intra-epithelial neoplasia: atypical lobular hyperplasia and lobular carcinoma in situ]

OBJECTIVE

To review main knowledge about lobular intra-epithelial neoplasia with special interest for daily practice management.

MAIN RESULTS

Intra-epithelial lobular neoplasias (ILN) are non invasive proliferations within the terminal ducto-lobular unit of monomorphic loosely cohesive small cells. A lack of expression of the E-cadherin adhesion molecule is often observed as in invasive lobular breast cancer. ILN are infrequent, however, a rise in incidence partly, due to the generalization of mammographic screening, is observed. Actually ILN are usually asymptomatic and diagnosed after breast biopsy for unspecified microcalcifications. ILN are associated with an increased risk of breast cancer that persists over 20 years after the initial diagnosis. The average risk is 4.2 % for the ipsilateral breast and 3,5 % for the controlateral breast. However, a great variability in the risk estimation is observed between the studies. There is no consensus on how to treat ILN. Surgical options have varied from biopsy to bilateral mastectomy. Current tendency is favouring lumpectomy.

[Breast lobular carcinoma in situ: diagnosis and evolution]

The incidence of lobular cancers in situ is increasing, especially in post-menopausal women. Whereas this form of disease was regarded for a long time as nothing but a risk factor of the occurrence of later infiltrating carcinoma, it now tends to represent a precancerous state whose progression to subsequent infiltrating carcinoma does not inevitably occur. The clinical and radiological diagnosis remains difficult and the choice of therapies varies according to teams, ranging from mere surveillance to mastectomy.

Breast-conserving surgery and radiotherapy: a possible treatment for lobular carcinoma in situ?

Lobular carcinoma in situ (LCIS) is generally treated by conservative surgery alone and less often by mastectomy. We report our experience using conservative surgery and whole breast irradiation (WBI) for the treatment of patients with LCIS. From 1980 to 1992, 25 women with a median age of 54 years underwent lumpectomy (20) or quadrantectomy (5) and WBI (median dose: 52 Gy) for treatment of their LCIS. Five cases had palpable lesions, 19 were found by mammography alone and one case was found due to nipple discharge. Twelve women received tamoxifen at 20 mg/day for 2 years. With a median follow-up of 153 months (range 58-240), only one local recurrence was observed. The global rate of bilateral carcinoma was 17.6% (two synchronous and one metachronous). Until now, no case of LCIS treated by lumpectomy and radiation therapy has been reported in detail in the literature. After biopsy alone for LCIS, a subsequent infiltrating carcinoma occurs in approximately 15% of cases. Thus, classical radiosurgical therapy should represent an interesting alternative both for limited surgery alone and mastectomy, both of which have been proposed as sole treatments for LCIS.

Interpretation of the risk associated with the unexpected finding of lobular carcinoma in situ

BACKGROUND

The risk of developing invasive breast cancer after finding lobular carcinoma in situ (LCIS) is controversially reported in the literature. The surgeon who finds LCIS unexpectedly may be tempted to remove the breast, or even remove both breasts.

METHODS

From 1976 to 1991, 157 consecutive women with palpable or mammographically detected breast lesions underwent surgery to resolve doubt as to the presence of invasive cancer. We report on the women in whom LCIS was found after diagnostic breast surgery and analyze the incidence of breast cancer after a mean 5 years of follow-up in comparison with that in the normal reference population.

RESULTS

Eight patients developed infiltrating breast carcinoma (four ipsilateral, four contralateral as first events), equal to a homolateral rate of 0.00625. The expected rate in the normal reference population is 0.00152; ratio 4.11 (95% confidence interval 1.1-10.5). For a contralateral event the rate ratio is 3.0 (95% confidence interval 0.8-7.6).

CONCLUSION

LCIS is one of many markers for later infiltrating cancer, so patients should be carefully followed. Ablative surgery is not justified.