Surgical excision may be avoidable for classic lobular neoplasia

SAN FRANCISCO — Surgical excision of classic lobular neoplasia diagnosed on calcification-targeting core biopsy can be avoided when careful imaging and pathology correlation is applied, according to results of a prospective study presented at the Breast Cancer Symposium.

“Lobular neoplasia, including atypical lobular hyperplasia or lobular carcinoma in situ (classic type), is a known pathologic marker of bilateral risk for subsequent breast cancer,” Barbara Susnik, MD, of Virginia Piper Cancer Institute in Minneapolis, told HemOnc Today. “The management of lobular neoplasia identified on core biopsy is controversial, in that recommendations are not established and practices vary. We identified a subset of patients who can avoid surgical excision: patients with lobular neoplasia identified on stereotactic core biopsy, who presented with calcifications on mammography.”

Barbara Susnik

Susnik and colleagues analyzed 13,772 percutaneous breast core biopsy procedures performed between June 2008 and December 2013.

The 370 patients with core biopsy-diagnosed lobular neoplasia received referrals for surgical excision. Of them, 302 (81.6%) patients with a combined 316 lesions underwent excision within 2 months of diagnosis.

Among those who underwent excision, the mean age was 55.3 years, 4% had prior breast carcinoma and 27% reported a positive family history.

Susnik and colleagues excluded patients for whom synchronous ipsilateral core biopsy showed cancer. The majority (77%) of the remaining 296 lesions were classic lobular neoplasia (LN-C), whereas 17.9% were flat epithelial atypia or atypical ductal hyperplasia (LN-DA), and about 5% were lobular carcinoma in situ variants (LN-V).

Dedicated breast pathologists and radiologists reviewed each case with careful imaging/pathology correlation, researchers wrote.

In the classic lobular neoplasia group, imaging/pathology discordance occurred in six of 228 cases (2.6%). Upgrade to carcinoma occurred in 8 of 222 concordant cases (3.6%) and all six discordant cases (100%).

Comparatively, upgrades occurred in 15 of 53 (28.3%) cases of flat epithelial atypia or atypical ductal hyperplasia, and in four of 15 (26.7%) cases of lobular carcinoma in situ variants.

Analysis showed calcifications were the imaging target in the majority (81%) of the concordant classic lobular neoplasia cases. Upgrade occurred in seven (3.9%) of those cases.

Researchers reported upgrade in 3.1% of mass lesions (n=1), and no upgrade in any of the 14 MRI-targeted lesions. Upgrade rates were similar between lobular carcinoma in situ (4.5%) and atypical lobular hyperplasia (3.4%).

“By employing careful pathologic–radiologic correlation, patients with concordant findings may be managed by close observation and possible chemoprevention, without undergoing surgical excision,” Susnik said. “By employing these new guidelines at our institution, many patients will be spared surgical excision. We will continue to recommend surgical management for patients with core biopsy diagnoses of non-classic variants of lobular neoplasia, or when lobular neoplasia is associated with ductal atypia — such as atypical ductal hyperplasia — due to substantial risk of upgrade to cancer in the surgical specimen.”

For more information:

Susnik B. Abstract #4. Presented at: Breast Cancer Symposium; Sept. 4-6, 2014; San Francisco.

Disclosure: The researchers report no relevant financial disclosures.