Trends in pre-biopsy MRI usage for prostate cancer detection, 2007–2022

Abstract

BACKGROUND:

Clinical guidelines favor MRI before prostate biopsy due to proven benefits. However, adoption patterns across the US are unclear.

METHODS:

This study used the Merative^™ Marketscan^® Commercial & Medicare Databases to analyze 872,829 prostate biopsies in 726,663 men from 2007–2022. Pre-biopsy pelvic MRI within 90 days was the primary outcome. Descriptive statistics and generalized estimating equations assessed changes over time, urban-rural differences, and state-level variation.

RESULTS:

Pre-biopsy MRI utilization increased significantly from 0.5% in 2007 to 35.5% in 2022, with faster adoption in urban areas (36.1% in 2022) versus rural areas (28.3% in 2022). Geographic disparities were notable, with higher utilization in California, New York, and Minnesota, and lower rates in the Southeast and Mountain West.

CONCLUSIONS:

The study reveals a paradigm shift in prostate cancer diagnostics towards MRI-guided approaches, influenced by evolving guidelines and clinical evidence. Disparities in access, particularly in rural areas and specific regions, highlight the need for targeted interventions to ensure equitable access to advanced diagnostic techniques.

INTRODUCTION

Clinical trials have demonstrated that MRI and targeted prostate biopsy strategies focused on detecting MRI-suspicious lesions reduce the need for invasive prostate biopsies and improve the detection of aggressive cancer [1–4]. In comparison to systematic transrectal ultrasound (TRUS) biopsy, MRI-guided approaches also reduce the overdiagnosis of low-risk cancers [1–4]. Based on these trials, clinical guidelines have evolved to favor MRI prior to prostate biopsy [5]. Despite its proven benefits, patterns of MRI and MRI-ultrasound fusion targeted biopsy adoption across the US remain unknown. This study examines trends in MRI utilization for prostate cancer diagnosis within the US from 2007 to 2022.

METHODS

Patient encounters were derived from the Merative^™ Marketscan^® Commercial (DOI: 10.57761/n5v8-0v21) & Medicare Databases (DOI: 10.57761/h9zd-f494), capturing a broad segment of the US population [6]. The MarketScan Claims includes administrative claims data for insured employees, their dependents, and Medicare-eligible retirees with employer-sponsored supplemental coverage. This data spans the period from 2007 to 2022 and encompasses various individuals, including active employees, early retirees, COBRA participants, and Medicare-eligible retirees. While the Medicare data primarily focuses on retirees with employer-sponsored supplemental plans, it also includes Medicare Advantage enrollees from 2020 onwards. The analysis was not restricted solely to Medicare beneficiaries but rather encompassed the broader spectrum of insured individuals within the databases.

We identified men aged 18 or older who underwent a prostate biopsy procedure in 2007–2022 based on a CPT code (55700) and calculated the proportion who underwent pelvic MRI (CPT codes 72195, 72196, 72197, 76377, 77021) in the 90 days prior to biopsy. Our primary outcome was the percentage of men receiving MRI prior to biopsy. Descriptive statistics summarized changes in MRI utilization over time. State-level variation in MRI use was examined. We also assessed differences across urban and rural areas based on the Metropolitan Statistical Area (MSA) of primary beneficiary, mapped from 5-digit employee ZIP. Yearly trend was analyzed using a generalized estimating equation model, accounting urban/rural area and its interaction with year. In the men undergoing biopsy (CPT code 55700), we further identified those diagnosed with prostate cancer (ICD-9 code 185 or ICD-10 code C61). Given the data was deidentified, the study was deemed exempt from informed consent requirements by the Stanford University Medical Center Institutional Review Board.

RESULTS

We identified 726,663 men who underwent 872,829 prostate biopsy procedures in the US from 2007–2022, with 374,121 of the men having prostate cancer. MRI utilization before prostate biopsy markedly increased each year from 0.5% in 2007 to 2.1% in 2012, 16.4% in 2017, and 35.5% in 2022 (Fig. 1), p < 0.001. Urban areas showed a faster rate of increase compared to rural areas, p < 0.001. In 2007, the urban-rural utilization gap was 0.63%. This increased to 7.8% by 2022 (Fig. 1). In 2022, MRI utilization prior to prostate biopsy was 28.3% in rural areas versus 36.1% in urban areas.

Fig. 1. Temporal trends in pre-biopsy MRI for prostate cancer diagnosis in the United States, and in urban and rural areas, 2007–2022.

Left panel highlights overall yearly rates. Right panel highlights yearly rates in urban and rural areas.

Substantial geographic disparities in MRI utilization were observed (Fig. 2). In 2011–2022, California, New York, and Minnesota were consistently among the top five states in MRI utilization. Between 2015–2018 and 2019–2022, utilization rates in these states increased markedly: Minnesota from 31.4% to 47.3%, New York from 25.8% to 37.8%, and California from 22.1% to 33.0%. In contrast, geographic clusters in the Southeast and Mountain West regions exhibited some of the lowest MRI utilization rates. In the Southeast, Tennessee’s rates increased from 9.5% in 2015–2018 to 17.9% in 2019–2022, Mississippi from 4.9% to 14.4%, and Arkansas from 10.4% to 15.2%. Meanwhile, in the Mountain West, Utah’s utilization rose from 6.3% to 20.9%, Colorado from 10.0% to 21.3%, and New Mexico from 6.5% to 15.6% over the same periods.

Fig. 2. Geographic trends in pre-biopsy MRI for prostate cancer diagnosis in the United States, 2007–2022.

A 2007–2010, B 2011–2014, C 2015–2018, and D 2019–2022. Information on states with fewer than 11 MRI-guided biopsies in each time period has been omitted.

DISCUSSION

The dramatic increase in pre-biopsy MRI utilization over a decade reflects a paradigm shift in prostate cancer diagnostics, driven by evolving guidelines and supportive clinical evidence. The increase utilization of MRI from <1% to 35% constitutes a relatively rapid change considering that integration of new technologies and paradigm shifts in healthcare often take decades to achieve. Indeed, MRI and targeted biopsy only began to gain popularity in the early 2010s. Clinical guidelines have evolved as evidence has accumulated in support of MRI and targeted biopsy. The NCCN first mentioned the potential use of MRI in 2014, in the context of excluding the presence of anterior cancer if PSA rises and systematic biopsies remain negative [7]. In 2016, the panel acknowledged that MRI may increase detection of high-risk disease while lowering detection of low-risk disease, yet avoided routinely recommending MRI before initial biopsy [8]. It was not until the 2023 guidelines that the NCCN recommended the use of MRI to determine initial and repeat biopsy [5]. Notably, the adoption of MRI seemed to increase even before this stronger recommendation, suggesting that clinicians were already recognizing its value.

Even with this significant progress and given the current clinical guidelines do recommend pre-biopsy MRI, only approximately 1 in 3 biopsies in 2022 were preceded by MRI. This highlights that while the adoption rate has been impressive, there is still considerable room for further integration of this valuable tool into standard clinical practice. Several barriers may exist that limit faster MRI adoption. Potential barriers could include limited access to MRI facilities, financial constraints for patients and healthcare systems, lack of insurance reimbursement, and the need for specialized training for radiologists and urologists. Persistent under-utilization of MRI provides an opportunity for quality improvement efforts, particularly in rural settings and in the Southeast and Mountain West where use of MRI is disproportionately lower.

Adoption of pre-biopsy MRI has also increased in other countries. For example, MRI prior to biopsy in Denmark increased from 22% in 2020, to 29% in 2021, and to 52% in 2022 [9]. This is consistent with the latest EAU-EANM-ESTRO-ESUR-ISUP-SIOG guidelines [10]. This rapid increase in a country with a different healthcare system suggests that the rising utilization of pre-biopsy MRI is a global trend reflecting the growing recognition of its clinical value in prostate cancer diagnosis.

Our study has noteworthy limitations. First, while the MarketScan database includes both commercial and Medicare data, the Medicare portion primarily focuses on Medicare-eligible retirees with employer-sponsored Medicare Supplemental plans, with the inclusion of Medicare Advantage enrollees from 2020 onwards. This may limit the generalizability of our findings to the broader Medicare population, particularly those enrolled solely in Medicare or Medicare Advantage plans without employer-sponsored supplemental coverage. Second, the MarketScan dataset does not include information on race, limiting our ability to fully investigate potential disparities in MRI utilization related to racial and ethnic backgrounds. However, we did examine MRI utilization across urban and rural areas to explore potential geographic disparities. Third, our study may underestimate MRI utilization because it does not include men who underwent prostate MRI but did not have a subsequent biopsy. Fourth, the proportion of the US population that the MarketScan database captures has been decreasing for many years which could mean the results are less representative of the total US population in later years.

Our findings highlight the rapid transformation of prostate cancer diagnosis and underscore the need for targeted strategies to bridge gaps in access, ensuring equitable benefits of precision medicine across all communities in the United States.