International Study Validates That Breast MRI Is Effective At Detecting Cancer In Dense Breasts
A new international study had validated that breast magnetic resonance imaging (MRI) is an effective diagnostic tool in detecting cancer in dense breasts.
The study comprised of researchers from the University of Toronto-Canada, University Health Network-Canada, Sinai Health System-United States, Women’s College Hospital-Canada, Worcestershire Acute Hospitals NHS Trust-United Kingdom, Princess Margaret Cancer Centre-Canada and McMaster University-Canada.
Prior to the study, there were lingering doubts about what available supplemental breast cancer screening modalitities in women at average risk or intermediate risk for breast cancer with dense breast and negative mammogram were truly effective.
The study team decided to conduct a systematic review and detailed meta-analysis comparing clinical outcomes of the most common available supplemental screening modalities in women at average risk or intermediate risk for breast cancer in patients with dense breasts and mammography with negative findings.
The study team conducted a comprehensive search until March 12, 2020, in Medline, Epub Ahead of Print and In-Process and Other Non-Indexed Citations; Embase Classic and Embase; Cochrane Central Register of Controlled Trials; and Cochrane Database of Systematic Reviews, for Randomized Controlled Trials and Prospective Observational Studies.
Incremental cancer detection rate (CDR); positive predictive value of recall (PPV1); positive predictive value of biopsies performed (PPV3); and interval CDRs of supplemental imaging modalities, digital breast tomosynthesis, handheld US, automated breast US, and MRI in non–high-risk patients with dense breasts and mammography negative for cancer were reviewed.
Data metrics and risk of bias were assessed. Random-effects meta-analysis and two-sided metaregression analyses comparing each imaging modality metrics were performed (PROSPERO; CRD42018080402).
A total of twenty-two studies reporting 261 233 screened patients were included.
The study findings showed that of 132 166 screened patients with dense breast and mammography negative for cancer who met inclusion criteria, a total of 541 cancers missed at mammography were detected with these supplemental modalities.
MRI was superior in detecting breast cancer with an incremental cancer detection rate (CDR) of 1.54 cancers per 1000 screenings (P < .001) on metaregression analysis.
Metaregression models showed that MRI was superior to other supplemental modalities in CDR (incremental CDR, 1.52 per 1000 screenings; 95% CI: 0.74, 2.33; P < .001), including invasive CDR (invasive CDR, 1.31 per 1000 screenings; 95% CI: 0.57, 2.06; P < .001), and in situ disease (rate of ductal carcinoma in situ, 1.91 per 1000 screenings; 95% CI: 0.10, 3.72; P < .04). No differences in PPV1 and PPV3 were identified.
However, the limited number of studies prevented assessment of interval cancer metrics. Excluding MRI, no statistically significant difference in any metrics were identified among the remaining imaging modalities.
The study findings were published in the peer reviewed journal: Radiology (RSNA).
The study findings validated that when compared to other common supplemental screening methods, breast MRI was superior at detecting breast cancer in women with dense breasts.
At present, breast cancer is one of the leading causes of cancer death in women. Roughly 47% of women in the United States have dense breasts, which is an independent risk factor of breast cancer. Women with dense breasts have a higher amount of glandular tissue and fibrous connective tissue and low amounts of fatty tissue in the breasts.
With the current ongoing COVID-19 pandemic, it is expected that breast cancer incidences will also go up exponentially as the SARS-CoV-2 virus does contribute to downregulating certain tumor suppressor genes, damaging and making NK cells and other T cells exhausted while also upregulating certain oncogenic genes not to mention that viral persistence is causing constant inflammatory issues.
Although screening mammography effectively detects up to 98% of cancer in fatty breasts, breast cancer is more easily missed in dense breasts. This results in a negative mammogram, giving patients false reassurance.
Study co-author, Dr Vivianne Freitas, M.D., M.Sc., assistant professor at the University of Toronto, Canada, and staff radiologist at the Joint Department of Medical Imaging in Toronto told Breast Cancer News
, "Breast cancer masses appear white on a mammogram, and dense tissue also appears white, which makes finding breast cancers within dense breast tissue harder for radiologists.”
In most cases, supplemental screening may be required to assist in cancer detection in women with dense breasts.
Currently, the four most common supplemental imaging tests are hand-held breast ultrasound, automated breast ultrasound, digital breast tomosynthesis and breast MRI.
Dr Freitas added, "This study was designed to evaluate the role of different supplementary screening tests in women of average or intermediate risk of breast cancer with dense breast tissue who had a negative screening mammogram.”
In order to evaluate which screening method was the most beneficial to women with dense breasts, the study team conducted a meta-analysis on 22 studies that included 261,233 patients screened for breast cancer.
Among these 22 identified studies, ten of the studies covered hand-held breast ultrasound, four studies covered automated breast ultrasound, three studies covered breast MRI, and eight studies reported on digital breast tomosynthesis.
It was also noted that of the patients included, 132,166 patients had dense breasts and a negative mammogram.
The study team utilized risk assessment models to identify patients with an average and intermediate risk of developing breast cancer.
At present in the United States, women with an estimated lifetime risk of 12 to 13% of developing breast cancer are considered average risk.
Identified factors that elevate the risk to intermediate include having a history of treated breast cancer or previous breast biopsies with high-risk lesions.
All high-risk patients, with a lifetime risk of 20% or higher, were excluded from the study since the benefit of breast MRI is already established in high-risk populations.
Detailed meta-analysis showed that of the 132,166 patients with dense breasts, a total of 541 breast cancers that were initially missed on mammography were detected with supplemental screening methods.
The study findings showed that breast MRI was the superior screening method and was capable of detecting even the smallest of cancers. Excluding MRI, there was not a significant difference between the other supplemental screening methods.
Dr Freitas commented, "Breast MRI is far superior in terms of cancer detection compared to hand-held ultrasound, automated ultrasound and digital breast tomosynthesis. Our study findings about the role of MRI in supplementary screening will allow stakeholders to guide healthcare policies in this setting and direct further research."
The study team stressed that although the research findings demonstrate the effectiveness of breast MRI in cancer detection, further detailed research is still warranted.
Dr Freitas explained, "Before we can advocate for wider application of breast MRI in these women, further evaluation of cost-effectiveness of breast MRI compared to other techniques, effect on mortality reduction, etc., will need to be studied. At the current time, availability and cost of the breast MRI remain the biggest barrier for widespread implementation."
The study team concluded that in women at average or intermediate risk for breast cancer with dense breasts and mammography negative for cancer undergoing supplemental screening, MRI had higher detection of breast cancer compared with handheld US, automated breast US, and digital breast tomosynthesis.
For the latest Breast Cancer News
, keep on logging to Thailand Medical News.