Radiation Oncology/Breast/LCIS

Risk of invasive cancer

• SEER data, 2005 (1973-98) - PMID 16110014 — "Bilateral risk for subsequent breast cancer after lobular carcinoma-in-situ: analysis of surveillance, epidemiology, and end results data." Chuba PJ et al. J Clin Oncol. 2005 Aug 20;23(24):5534-41.
  • Incidence of invasive carcinoma 7.1% at 10 yrs, 18% at 25 yrs.
  • 46% ipsilateral / 54% contralateral. Higher proportion of cancers with ILC than in the general population (23.1% vs 6.5%).
  • Conclusion: LCIS is associated with increased risk of subsequent invasive breast cancer, which can occur with roughly equal probability in either breast.

Prevention of invasive cancer

• P-1 prevention trial
  • See page at Prevention for detail.
  • 43% risk reduction with tamoxifen overall (46% for those with LCIS).

Surgery alone

• NSABP - PMID 14716756 — "Pathologic findings from the National Surgical Adjuvant Breast and Bowel Project: twelve-year observations concerning lobular carcinoma in situ." Fisher ER et al. Cancer. 2004 Jan 15;100(2):238-44.
  • Analysis of previous NSABP trial. 12-year results of 180 pts treated with surgical excision only.
  • IBTR in 14.4% and CBTR in 7.8%. 9 of 26 IBTR and 10 of 14 CBTR were invasive, mostly invasive lobular carcinoma.
  • Conclusion: LCIS is an indolent disease and can be managed with conservative surgery

LCIS concurrent with breast carcinoma

• U. Michigan; 2006 (1989-2003) PMID 16329136 -- "Is lobular carcinoma in situ as a component of breast carcinoma a risk factor for local failure after breast-conserving therapy? Results of a matched pair analysis." (Ben-David MA, Cancer. 2006 Jan 1;106(1):28-34.)
  • Retrospective. 64 pts with Stage 0-II (DCIS or invasive ca.) breast carcinoma with LCIS as a component of the primary tumor. Compared with matched controls (LCIS-).
  • Conclusion: The extent of LCIS and its presence at the margins did not reduce the excellent rates of local control after BCS+RT. The data suggest that LCIS in the tumor specimen, even when multifocal, should not affect selection of patients for BCS and whole-breast RT.

Pleomorphic LCIS

Uncommon (12% of LCIS cases). May be associated with invasive carcinoma (usually invasive lobular) 25% of the time. Biologically can behave similar to high grade DCIS.

Treatment is controversial. Some recommend complete excision with negative margins (see NCCN Guidelines 2011-1).

• 2013: Review PMID 23357705 Full text -- "Challenges in the management of pleomorphic lobular carcinoma in situ of the breast." (Masannat YA, Breast. 2013 Apr;22(2):194-6.)

• 2012: Case report - PMID 22037287 Full text -- "Pleomorphic lobular carcinoma in situ: treatment options for a new pathologic entity." (Murray L, Clin Breast Cancer. 2012 Feb;12(1):76-9.)

• 2011: MDACC - PMID 21631266 -- "Clinical implications of margin involvement by pleomorphic lobular carcinoma in situ." (Downs-Kelly E, Arch Pathol Lab Med. 2011 Jun;135(6):737-43.)
  • Conclusion: "This is the first series, to our knowledge, that evaluates margin status in patients with PLCIS and documents recurrence. Recurrent PLCIS was identified at a rate similar to low- or intermediate-grade ductal carcinoma in situ. Therefore, known methods of local control, including surgical excision with negative margins (2 mm), may be the appropriate treatment in these patients."

Reviews

• 2011 (MSKCC) No PMID yet Full text -- "Recommendations for Women With Lobular Carcinoma In Situ (LCIS)" (Oppong BA, Oncology. 2011 Oct 12;25(11)