Surgical attitudes toward preoperative breast magnetic resonance imaging in women with early-stage breast cancer

Does Preoperative MRI Reduce Positive Margins after Breast-Conserving Surgery?

BACKGROUND

Breast-conserving surgery (BCS) is a mainstay for breast cancer management, and obtaining negative margins is critical. Some have advocated for the use of preoperative magnetic resonance imaging (MRI) in reducing positive margins after BCS. We sought to determine whether preoperative MRI was associated with reduced positive margins.

PATIENTS AND METHODS

The SHAVE/SHAVE2 trials were multicenter trials in ten US centers with patients with stage 0-3 breast cancer undergoing BCS. Use of preoperative MRI was at the discretion of the surgeon. We evaluated whether or not preoperative MRI was associated with margin status prior to randomization regarding resection of cavity with shave margins.

RESULTS

A total of 631 patients participated. Median age was 64 (range 29-94) years, with a median tumor size of 1.3 cm (range 0.1-9.3 cm). Patient factors included 26.1% of patients (165) had palpable tumors, and 6.5% (41) received neoadjuvant chemotherapy. Tumor factors were notable for invasive lobular histology in 7.0% (44) and extensive intraductal component (EIC) in 32.8% (207). A preoperative MRI was performed in 193 (30.6%) patients. Those who underwent preoperative MRI were less likely to have a positive margin (31.1% versus 38.8%), although this difference was not statistically significant (p = 0.073). On multivariate analysis, controlling for patient and tumor factors, utilization of preoperative MRI was not a significant factor in predicting margin status (p = 0.110). Rather, age (p = 0.032) and tumor size (p = 0.040) were the only factors associated with margin status.

CONCLUSION

These data suggest that preoperative MRI is not associated margin status; rather, patient age and tumor size are the associated factors.

Perioperative magnetic resonance imaging in breast cancer care: Distinct adoption trajectories among physician patient-sharing networks

BACKGROUND

Despite no proven benefit in clinical outcomes, perioperative magnetic resonance imaging (MRI) was rapidly adopted into breast cancer care in the 2000's, offering a prime opportunity for assessing factors influencing overutilization of unproven technology.

OBJECTIVES

To examine variation among physician patient-sharing networks in their trajectory of adopting perioperative MRI for breast cancer surgery and compare the characteristics of patients, providers, and mastectomy use in physician networks that had different adoption trajectories.

METHODS AND FINDINGS

Using the Surveillance, Epidemiology, and End Results-Medicare database in 2004-2009, we identified 147 physician patient-sharing networks (caring for 26,886 patients with stage I-III breast cancer). After adjusting for patient clinical risk factors, we calculated risk-adjusted rate of perioperative MRI use for each physician network in 2004-2005, 2006-2007, and 2008-2009, respectively. Based on the risk-adjusted rate, we identified three distinct trajectories of adopting perioperative MRI among physician networks: 1) low adoption (risk-adjusted rate of perioperative MRI increased from 2.8% in 2004-2005 to 14.8% in 2008-2009), 2) medium adoption (8.8% to 45.1%), and 3) high adoption (33.0% to 71.7%). Physician networks in the higher adoption trajectory tended to have a larger proportion of cancer specialists, more patients with high income, and fewer patients who were Black. After adjusting for patients' clinical risk factors, the proportion of patients undergoing mastectomy decreased from 41.1% in 2004-2005 to 38.5% in 2008-2009 among those in physician networks with low MRI adoption, but increased from 27.0% to 31.4% among those in physician networks with high MRI adoption (p = 0.03 for the interaction term between trajectory group and time).

CONCLUSIONS

Physician patient-sharing networks varied in their trajectory of adopting perioperative MRI. These distinct trajectories were associated with the composition of patients and providers in the networks, and had important implications for patterns of mastectomy use.

Are we choosing wisely? Drivers of preoperative MRI use in breast cancer patients

INTRODUCTION

Factors contributing to the use of preoperative MRI remain poorly understood.

METHODS

Data from a randomized controlled trial of stage 0-3 breast cancer patients undergoing breast conserving surgery between 2016 and 2018 were analyzed.

RESULTS

Of the 396 patients in this trial, 32.6% had a preoperative MRI. Patient age, race, ethnicity, tumor histology, and use of neoadjuvant therapy were significant predictors of MRI use. On multivariate analysis, younger patients with invasive lobular tumors were more likely to have a preoperative MRI. Rates also varied significantly by individual surgeon (p < 0.001); in particular, female surgeons (39.9% vs. 24.0% for male surgeons, p = 0.001) and those in community practice (58.9% vs. 14.2% for academic, p < 0.001) were more likely to order preoperative MRI. Rates declined over the two years of the study, particularly among female surgeons.

CONCLUSIONS

Preoperative MRI varies with patient age and tumor histology; however, there remains variability by individual surgeon.

Preoperative Breast MRI in Women 35 Years of Age and Younger with Breast Cancer: Benefits in Surgical Outcomes by Using Propensity Score Analysis

Background The role of preoperative MRI in women 35 years of age or younger with breast cancer remains controversial. Purpose To determine the association between preoperative MRI and surgical outcomes in women aged 35 years or younger with breast cancer by using propensity score (PS) analysis to investigate the impact of preoperative MRI. Materials and Methods Women 35 years of age or younger diagnosed with breast cancer between 2007 and 2017 who had or had not undergone preoperative breast MRI were retrospectively identified. The MRI detection rate of additional suspicious lesions was analyzed, and changes in surgical management were recorded. Inverse probability weighting (IPW) and PS matching were used to adjust 19 variables and to create a balance between the two groups. Surgical outcomes were compared by using univariable logistic regression. Results Among 964 women (mean age ± standard deviation, 32 years ± 3), 665 (69%) had undergone preoperative MRI (MRI group; mean age, 32 years ± 3) and 299 (31%) had not (no-MRI group; mean age, 32 years ± 3). In the MRI group, additional suspicious lesions were found in 178 of the 665 women (27%), with 88 of those 178 women (49%) having malignant lesions. The surgical management was changed in 99 of the 665 women (15%) due to MRI findings, which was appropriate for 62 of those 99 women (63%). In the IPW analysis, the MRI group showed lower odds of repeat surgery (odds ratio [OR], 0.13; 95% CI: 0.07, 0.21; P < .001) and higher odds of initial mastectomy (OR, 1.62; 95% CI: 1.17, 2.25; P = .004). However, there was no difference in the overall mastectomy rate (OR, 1.24; 95% CI: 0.91, 1.68; P = .17) compared with the no-MRI group. These results were consistent when using the PS matching method. Conclusion Preoperative MRI in young women with breast cancer is useful for detecting additional malignancy and improving surgical outcomes by reducing the repeat surgery rate, with a similar likelihood of overall mastectomy. © RSNA, 2021 Online supplemental material is available for this article.