Additional Workups Recommended During Preoperative Breast MRI: Methods to Gain Efficiency and Limit Confusion

The Impact of Preoperative Breast MRI on Timing of Surgical Management in Newly Diagnosed Breast Cancer

Purpose: Preoperative breast MRI has been recommended at our center since 2016 for invasive lobular carcinoma and cancers in dense breasts. This study examined how preoperative breast MRI impacted surgical timing and outcomes for patients with newly diagnosed breast cancer. Methods: Retrospective single-center study of consecutive women diagnosed with new breast cancer between June 1, 2019, and March 1, 2021, in whom preoperative breast MRI was recommended. MRI, tumor histology, breast density, post-MRI biopsy, positive predictive value of biopsy (PPV3), surgery, and margin status were recorded. Time from diagnosis to surgery was compared using t-tests. Results: There were 1054 patients reviewed, and 356 were included (mean age 60.9). Of these, 44.4% (158/356) underwent preoperative breast MRI, and 55.6% (198/356) did not. MRI referral was more likely for invasive lobular carcinoma, multifocal disease, and younger patients. Following preoperative MRI, 29.1% (46/158) patients required additional breast biopsies before surgery, for a PPV3 of 37% (17/46). The time between biopsy and surgery was 55.8 ± 21.4 days for patients with the MRI, compared to 42.8 ± 20.3 days for those without (P < .00001). MRI was not associated with the type of surgery (mastectomy vs breastconserving surgery) (P = .44) or rate of positive surgical margins (P = .52). Conclusion: Among patients who underwent preoperative breast MRI, we observed significant delays to surgery by almost 2 weeks. When preoperative MRI is requested, efforts should be made to mitigate associated delays.

Local Recurrence After Breast-Conserving Therapy in Patients With Multiple Ipsilateral Breast Cancer: Results From ACOSOG Z11102 (Alliance)

PURPOSE

Breast-conserving therapy (BCT) is the preferred treatment for unifocal breast cancer (BC). The oncologic safety of BCT for multiple ipsilateral breast cancer (MIBC) has not been demonstrated in a prospective study. ACOSOG Z11102 (Alliance) is a phase II, single-arm, prospective trial designed to evaluate oncologic outcomes in patients undergoing BCT for MIBC.

PATIENTS AND METHODS

Women age 40 years and older with two to three foci of biopsy-proven cN0-1 BC were eligible. Patients underwent lumpectomies with negative margins followed by whole breast radiation with boost to all lumpectomy beds. The primary end point was cumulative incidence of local recurrence (LR) at 5 years with an a priori rate of clinical acceptability of <8%.

RESULTS

Among 270 women enrolled between November 2012 and August 2016, there were 204 eligible patients who underwent protocol-directed BCT. The median age was 61 years (range, 40-87 years). At a median follow-up of 66.4 months (range, 1.3-90.6 months), six patients developed LR for an estimated 5-year cumulative incidence of LR of 3.1% (95% CI, 1.3 to 6.4). Patient age, number of sites of preoperative biopsy-proven BC, estrogen receptor status and human epidermal growth factor receptor 2 status, and pathologic T and N categories were not associated with LR risk. Exploratory analysis showed that the 5-year LR rate in patients without preoperative magnetic resonance imaging (MRI; n = 15) was 22.6% compared with 1.7% in patients with a preoperative MRI (n = 189; P = .002).

CONCLUSION

The Z11102 clinical trial demonstrates that breast-conserving surgery with adjuvant radiation that includes lumpectomy site boosts yields an acceptably low 5-year LR rate for MIBC. This evidence supports BCT as a reasonable surgical option for women with two to three ipsilateral foci, particularly among patients with disease evaluated with preoperative breast MRI.