Early cancer detection is critical to achieving better treatment outcomes. The earlier that cancer is detected, the easier it is to treat—in terms of how susceptible it is to treatment, how invasive those treatments need to be, and subsequently, how much they affect quality of life. The WHO estimates that early detection and intervention could prevent 30-50 percent of all cancer cases.
Technological advances in healthcare are leading to new and improved screening methods capable of detecting cancer earlier. Two leading methods are MRI (magnetic resonance imaging) scans and liquid biopsies. Screening forms a key element of preventive healthcare - where early detection and disease prevention are encouraged to maintain long-term health. This article will explain what MRIs and liquid biopsies are and how they work in cancer screening. We will then discuss the advantages and disadvantages of the two screening methods and how to decide which is best for you.
A liquid biopsy is a test that analyzes the presence of cancer markers in biological fluids such as blood, urine, and saliva. The most common fluid used is blood. If abnormalities are detected in the biological fluid, further tests will be performed to confirm whether cancer is present.
Liquid biopsies work by testing for the presence of tumor-derived materials in the blood such as:
The presence and amount of these materials in the blood can provide information crucial to the diagnosis and treatment of cancer, such as the type of cancer, how developed the cancer is, and other disease signature information. Tumor-derived materials may be present in the blood before obvious symptoms, resulting in early cancer diagnosis.
MRI scans produce a detailed image of internal organs or tissues to identify anomalies or early signs of cancer. Their ability to distinguish between different types of soft tissues makes them particularly effective at detecting soft tissue cancers, such as breast or brain cancers. The high level of detail obtained from an MRI scan is sufficient to identify the earliest signs of cancer, distinguish malignant and benign tumors, and even identify whether the cancer is aggressive or non-aggressive.
Due to its ability to detect the earliest signs of cancer, MRIs can be used for cancer screening. This could be a general screening in the form of a full-body MRI, such as those carried out by Ezra, where the entire body is scanned for abnormalities or tumors indicative of cancer. Full-body MRIs also have the added benefit of identifying if the cancer has metastasized and is present elsewhere in the body. These scans are further recommended for those at an increased risk of cancer, such as due to a genetic predisposition. MRIs can be used for more specific organ screenings, such as breast screenings for high-risk individuals - MRIs can detect breast cancer with 90 percent sensitivity compared to 37.5 percent for mammograms - or prostate cancer screenings to avoid unnecessary invasive prostate biopsies.
Liquid biopsies and MRI scans are both used in the early detection of cancers. MRI has a high sensitivity (the probability of a positive result in a patient with cancer) for detecting cancers. For example, in breast cancer, the sensitivity ranges between 81 percent and 100 percent, and in brain cancer, it can be as high as 98.9 percent using advanced MRI techniques. Specificity (the probability of a negative result in a patient without cancer) is lower than sensitivity in MRIs, although this does depend on the type of cancer and whether previous screening rounds have been carried out.
MRIs are particularly effective at locating tumors. Liquid biopsies can have high sensitivity and specificity - cancer type dependent - and can detect certain biomarkers before any visible signs of tumors can be detected. However, at the earliest stages of some types of cancer, insufficient levels of biomarkers are released for the biopsies to detect. This could result in false negatives.
Liquid biopsies typically analyze cancer biomarkers in blood, which makes them particularly effective at detecting blood cancers, such as leukemia or lymphoma, where the cancer cells and cancer DNA will readily circulate in the blood. The ability of MRIs to distinguish between different types of soft tissue makes them particularly effective at identifying soft tissue cancers, such as breast cancer or brain cancer.
MRIs can offer visualization of tumor size and location and may be able to offer insight into how aggressive the cancer is. Small early tumors and other abnormalities can be identified very early in cancer progression, potentially even before any symptoms have materialized. Liquid biopsies also show potential in the early detection of cancer (although this is test-dependent) and can offer insights into the molecular characteristics of the cancer, which may provide improved personalized treatment options specific to the molecular signature of the cancer. In the future, liquid biopsies may also be able to detect multiple cancers at once, which could be life-saving for those with cancer types not regularly screened for.
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Both liquid biopsies and MRIs are effective at detecting cancer early; however, both have advantages and disadvantages. MRI scans are more effective at detecting physical tumors and are recommended for those with genetic predispositions or a family history of cancer. Liquid biopsies are particularly effective for blood-based monitoring and may be able to detect tumors before they are visible on an MRI for some cancers.
Different screening methods may be recommended based on an individual’s health history and risk of cancer. As with all screening tests, your healthcare professionals will know best and will be able to advise you on what method of screening will be most effective for you. This could include MRIs, liquid biopsies, other screening methods, or a combined approach for comprehensive screening.
Early detection is key to catching cancer when at its most treatable. MRI scans and liquid biopsies are both effective methods for the early detection of cancer and are therefore, important to consider as part of preventive healthcare. MRIs produce a detailed image of the body where anomalies and tumors can be detected with high sensitivity. Liquid biopsies detect the presence of tumor-derived materials in the blood and, in some instances, can detect tumors before they are visible using imaging techniques. Both screening methods have advantages and disadvantages, so consulting with your healthcare professional is essential to deciding which will work best for you.
If you want to be proactive about your health, why not book an Ezra full-body MRI? Our annual scan catches potential cancer earlier, leveraging AI through the screening process to make it more efficient, affordable, and faster.
