Importance of Presurgical Breast MRI in Patients 60 Years of Age and Older

INTRODUCTION

Breast Magnetic Resonance Imaging (MRI) is routinely recommended as a screening tool for women who are at increased risk for breast cancer, due to the high sensitivity (94-100%) of this imaging modality. Over the years, breast MRI has also been utilized to evaluate patients presurgically after a breast cancer diagnosis. However recommendations on such use of the technology remain contested. The American Cancer Society (ACS) has issued recommendations on the use of screening breast MRI, supported by the American College of Radiology (ACR) and the Society of Breast Imaging (SBI).[1] However, the ACS recommendations do not specifically address the use of breast MRI in the presurgical setting. The ACR and the European Society of Breast Imaging have provided guidelines on the recommended indications for use of breast MRI, and the extent of disease evaluation after a newly diagnosed breast cancer is one among these.[23] These recommendations state that MRI determines the extent of disease more accurately than standard mammography and physical examination, though it remains to be shown that there is a reduction in recurrence rates.

Presurgical breast MRI has been shown to detect otherwise occult ipsilateral cancer in 6-27%[456] of patients and contralateral malignancy in 3-9% of patients.[478910] Contrary to this, studies have argued that presurgical MRI can lead to potentially unnecessary surgery.[1112131415161718] Houssami has contended in serveral publications that there is evidence that MRI does change surgical management; however, there is no evidence that it improves surgical treatment or outcomes.[11151718]

There is extensive literature on presurgical breast MRI evaluation. However, to our knowledge, only a few studies to date have specifically reviewed the impact on the aging/postmenopsausal patient population. A recent article by Fortune-Greeley has shown that obtaining preoperative MRI in patients with invasive lobular carcinoma (ILC) reduces the reoperation rates and overall has mastectomy rates similar to those of patients not undergoing a breast MRI.[19] Aging women have an increased risk of breast cancer; by 50 years of age, there is a 2.38% risk (1 in 42), and by age of 60 years, there is a 3.56% risk (1 in 28).[20] Combined with this already increased risk of developing breast cancer, once a woman is diagnosed with breast cancer, her 10-year risk of developing local recurrence can be up to 10%.[17] Given that the aging patient population has an increased risk of developing breast cancer, and when combining this with the risk of developing another cancer after the original diagnosis, we feel that this population is an important group to evaluate presurgically with breast MRI. Because of this, we reviewed our patient outcomes in order to demonstrate the importance of performing presurgical bilateral breast MRI in women of age 60 years and above.

MATERIALS AND METHODS

Institutional review board approval with waiver of informed consent was obtained for this Health Insurance Portability and Accountability Act (HIPAA) compliant retrospective review. One thousand two hundred and sixty-eight patients of age 60 years and above with a breast cancer diagnosis, either invasive carcinoma (ductal and lobular) or ductal carcinoma in situ (DCIS), or an atypical diagnosis (lobular neoplasm, atypical ductal hyperplasia, atypical lobular hyperplasia, papillary neoplasm), undergoing presurgical bilateral breast MRI examination at our community-based private practice from December 2003 to December 2011 were reviewed. Through our outcomes database, we identified 310 new lesions identified on a presurgical breast MRI exam. To be included in this analysis, the criteria were: All patients of age 60 years and above, having had a presurgical bilateral breast MRI exam and a newly discovered and suspiciously enhancing lesion identified on the MRI exam, classified using the ACR's Breast Imaging Reporting and Data System as a BI-RADS 4 or BI-RADS 5, and having undergone additional evaluation and needle biopsy. Upon reviewing the data, 38 findings were excluded due to incomplete or missing data, thus making 243 patients with 272 MRI findings eligible for inclusion in the study analysis. Data recorded included patient demographics, additional findings at MRI, targeted ultrasound findings, core biopsy method and pathology, type of surgery, and open surgical pathology results.

RESULTS

Out of 1268 presurgical bilateral MRI exams performed in patients aged 60 years and above, there were a total of 272 suspicious MRI findings in 243 patients available for the study and analysis. Average patient age was 68 years (range 60-90 years).

All 272 suspicious MRI findings underwent needle biopsy, giving a resultant biopsy rate of 21.0% (272/1268). Of these biopsies performed, MRI-guided core needle biopsy was performed in 128 (47%), with pathology tests showing 43 malignant, 65 benign, and 20 atypical results. Ultrasound-guided core needle biopsy was performed in 103 (38%), with pathology tests showing 56 malignant, 39 benign, and 8 atypical results. Stereotactic core needle biopsy was performed in 21 (8%), with pathology tests showing 14 malignant, 6 benign, and 1 atypical lesions. Fine needle aspiration was performed in 20 (7%), with pathology tests showing 1 malignant, 17 benign, and 2 atypical results. There was a second look ultrasound correlate in 44.4% (121/272) of which 56 malignancies were identified. Pathology of malignant and atypical lesions are presented in Tables 1 and 2, respectively. A positive predictive value of 9.0% was found (114/1268); false-positive rate was 10% (127/1268).

Table 1 Pathology of new malignant lesions detected on breast MRI

Table 2 Pathology of new atypical lesions detected on breast MRI

Of the 114 malignancies, 83 were in the ipsilateral breast and 31 in the contralateral breast. Of the ipsilateral findings, 47 were in the same quadrant as the primary diagnosis, 28 in a different quadrant, and 8 were metastatic lymph nodes. Of the 31 atypical findings, 14 were contralateral to the primary diagnosis and 17 were ipsilateral (8 in a different quadrant and 9 in the same quadrant).

A total of 234 patients with 262 findings underwent surgical excision. There was a change in surgical management as a result of the newly discovered and suspiciously enhancing finding on the MRI exam for 111 patients (111/1268, 8.8%). Forty-five patients (45/1268, 3.6%) changed management from lumpectomy to mastectomy. Sixty-four patients (64/1268, 5.1%) underwent bilateral surgery. Two patients (2/1268, 0.2%) opted to have a wider lumpectomy procedure. Eight patients (10 lesions) did not undergo surgical excision. For five patients (7 lesions), the new MRI finding was in the contralateral breast and was biopsy-proven benign, so the lesion was not surgically excised. Three patients (3 lesions), who had additional testing preoperatively (by their surgeon), were found to have advanced disease after the MRI examination and underwent treatment other than surgical excision.

One patient did choose to undergo bilateral mastectomy based on a new contralateral MRI finding that was proven to be benign on biopsy.

DISCUSSION

Presurgical breast MRI has the ability to detect otherwise undetected malignancies, which has been demonstrated by many published studies.[45678910192021222324252627] In our analysis of women of age 60 years and above undergoing presurgical bilateral breast MRI, we found additional malignancy in 9% of the patients (114/1268). Of these new malignancies, 2.4% were in the contralateral breast. This drastically changes the management of the patient, and is important information to be able to provide to our patients prior to surgery. We found in our patient cohort that 8.8% (n = 111/1268) of them had a surgical change in management based on the MRI findings. Despite the ability of presurgical breast MRI to detect new malignancies, there is opposition in the United States to performing breast MRI prior to surgery. It has been reported that there is no consistent evidence that preoperative breast MRI is beneficial to the patient.[28] It is reported that preoperative MRI can change the management in ways that can ultimately be harmful to patients, such as increased mastectomy rates, increased work-ups, and delays to surgical excision.[29] In our patient cohort, there was only one case where a benign biopsy result led the patient to undergo more extensive surgery. Most recently, in 2014, Houssami et al., conducted a meta-analysis evaluating the association between preoperative MRI and local recurrence as well as distant recurrence in patients with breast cancer.[18] Preoperative MRI was not found to reduce the risk of local or distant recurrence, ultimately leading the authors to state that preoperative MRI should not be used routinely, but it would be helpful in certain situations such as evaluating axillary node metastases or unknown primary cancer. However, it is important to note that this meta-analysis only evaluated MRI in the ipsilateral breast and did not review MRI findings in the contralateral breast. Conversely, Fortune-Greeley and colleagues presented evidence supporting the use of preoperative MRI for surgical planning in elderly women with ILC.[19] They reported that 20.6% of all patients had an additional reoperation after initial breast conserving surgery and those with ILC were found to have the highest percentage of reoperation rates. The study reported, after propensity score adjustments, that having a presurgical breast MRI lowered the odds of having reoperation in this group. Dr. Lehman and colleagues reported on MRI evaluation of the contralateral breast in women with recently diagnosed breast cancer. They evaluated patients in the age group of 18 years and above, with post-menopausal women comprising over half of the group studied (57.2%).[9] Overall, this study demonstrated the value of performing bilateral presurgical breast MRI in patients with a recently diagnosed breast cancer. In addition, when specifically reviewing the post-menopausal cohort, it was reported that in 3.1%, MRI detected cancer in the contralateral breast otherwise missed by mammography and clinical examination. The number of cancers detected was not influenced by menopausal status or histological features of the primary tumor. Our study found 31 (2.4%) contralateral breast cancers (31/1268) in patients 60 years and above, demonstrating value in the aging population as well.

CONCLUSION

Bilateral breast MRI does detect additional malignancies that may otherwise go undetected, ultimately leading to more extensive surgical plans which can eliminate multiple subsequent surgical procedures for the patient. This study shows that performing presurgical bilateral breast MRI is of value in patients 60 years of age and older and for all subtypes of breast cancer.