Women with Low-Risk DCIS Eligible for the LORIS Trial After Complete Surgical Excision: How Low Is Their Risk After Standard Therapy?

Abstract

Background Identifying DCIS patients at low risk for disease progression could obviate need for standard therapy. The LORIS (surgery versus active monitoring for low-risk DCIS) trial is studying the safety of monitoring low-risk DCIS, although ipsilateral breast tumor recurrence (IBTR) rates in patients meeting enrollment criteria after complete surgical excision are unknown. Methods Women with pure DCIS treated with breast-conserving surgery (BCS) with/without radiation therapy (RT) from 1/1996–1/2011 were included from a prospectively maintained database. IBTR rates were compared between those who did and did not meet LORIS eligibility criteria (age ≥46yrs, screen-detected calcifications, nipple discharge absence, minimal family history, non-high–grade DCIS) after complete surgical excision. Results 2394 women were identified; 401 met LORIS criteria. Median follow-up was 5.9yrs; 431 had ≥10yrs follow-up. LORIS cohort median age was 61yrs (range: 46–86yrs); 207 (52%) underwent RT, 79(20%) received endocrine therapy. 24 of 401 experienced an IBTR. Overall 10-year IBTR rates were 10.3% (LORIS) versus 15.4% (non-LORIS)(p=0.08); without RT, 12.1% versus 21.4%, respectively (p=0.06). 10-year invasive-IBTR rates for women meeting LORIS criteria were: 5.3% BCS overall; 6.0% without RT. Conclusion Women meeting LORIS criteria (after complete surgical excision) are at somewhat lower risk for IBTR. Among such women undergoing excision without RT, the 10-year invasive-IBTR rate was 6%. Given approximately 20% of women with core-biopsy–proven non-high–grade DCIS have invasive cancer at excision, women managed without excision would be expected to incur higher invasive cancer rates. Additional criteria are needed to identify women not requiring intervention for DCIS.

Outcomes for Women with Minimal-Volume Ductal Carcinoma In Situ Completely Excised at Core Biopsy

“…22 Further, among women with DCIS who continued to meet LORIS criteria even after examination of the complete surgical excision specimen, the 10-year IBE rate was a substantial 12.1%. 23 Our current data show that in our entire population of women with very low-volume DCIS, and in the subsets of those age ≥50 years and those with low-grade DCIS, risk of IBE was clinically significant at 10-years: 12.3% (entire population), 12.6% (age ≥50 years), and 14.6% (low grade, including cases borderline between ADH and DCIS), respectively. In our 207 mDCIS patients not receiving radiation, all of whom underwent surgical excision demonstrating complete DCIS removal by the core biopsy, the 10-year IBE rate was 14.7%, and in the subset with low-grade DCIS, 13.9%.…”

Behaviour and characteristics of low‐grade ductal carcinoma in situ of the breast: literature review and single‐centre retrospective series

“…A retrospective study by Pilewskie et al . evaluated the risk of ipsilateral tumour recurrence after BCS with or without radiotherapy for women who met the inclusion criteria for the LORIS trial and found that 24 of 401 (6.0%) patients experienced an ipsilateral recurrence.…”

Wherein the Authors Attempt to Minimize the Confusion Generated by Their Study “Breast Cancer Mortality after a Diagnosis of Ductal Carcinoma In Situ” by Several Commentators Who Disagree with Them and a Few Who Don’t: A Qualitative Study

“…Most articles accurately stated that the mortality rate from dcis is low (3%) and that mortality was equivalent regardless of treatment type. Nevertheless, many commentators misinterpreted the finding of low mortality to infer either that dcis is a precursor, and not a cancer [15][16][17][18] ; that dcis is overdiagnosed and does not need to be treated (that is, "watch and wait") [19][20][21][22][23][24][25][26][27][28][29] ; or that dcis is overtreated (that is, omit radiotherapy) [30][31][32][33][34] . Most troubling from our point of view was that several commentators interpreted the finding that the increased risk of death from breast cancer in dcis patients who developed an ipsilateral invasive recurrence justified efforts to prevent the invasive ipsilateral recurrence as a life-saving measure [35][36][37][38][39][40][41][42][43] .…”

“…For example, Pilewskie et al 15 cite our paper in support of the statement that "ductal carcinoma in situ (dcis) is a noninvasive breast lesion with no theoretic metastatic potential and excellent survival"; Shieh et al 16 deem dcis "likely to be a true precursor lesion" rather than a cancer; Ganz et al 17 note that treatment for dcis is "thought of as breast cancer prevention, because ductal carcinoma in situ is rarely lethal"; and Masood et al 18 suggest that our paper "raises the question of why we are calling an entity 'cancer' when it does not act like a malignant lesion," which is "sufficient evidence to consider a definitive change in the use of the term 'carcinoma in situ' and replace it with a less threatening terminology." It is interesting to note that in regard to that issue (and the three other issues discussed in the subsections that follow), none of the commentators actually said that we were wrong-that is, that dcis is not a fully-fledged cancer.…”