Blood plays a crucial role in our bodies, carrying oxygen and nutrients while regulating temperature and protecting us from infection. In recent years, scientists have discovered that blood may hold the secret to detecting certain types of cancer.
Most cancers start in one organ and grow, releasing fragments of cancer cells into the bloodstream. These circulating tumor DNA (ctDNA) fragments can be detected through blood tests, which are changing how cancer is diagnosed, treated, and monitored.
However, there’s a downside: these tests aren’t very effective at detecting precancerous or early-stage cancers. For example, they may miss stage 1 colorectal cancers or identify only half of them. This limitation makes it crucial to use other screening methods, such as stool tests or colonoscopies, which can detect precancerous polyps.
Another concern is cross-reactivity, where the test detects something other than its intended target due to similarities in structure. This can lead to false positives and diagnostic odysseys for physicians.
On the flip side, certain blood tests can help detect some deadly cancers before symptoms appear. These tests can identify aggressive cancers like pancreatic or ovarian cancer at earlier stages when treatment is more effective. They also enable doctors to predict with greater accuracy whether a patient has recurred after surgery or chemotherapy.
In fact, tumor-informed blood tests that individualize the test from your specific tumor can help determine if a recurrence is occurring. These tests sequence the DNA from a piece of your tumor and then test your blood for genetic mutations specific to your cancer tissue.
For patients, this means having peace of mind knowing whether their tumor has returned or not. It also helps doctors identify which patients need chemotherapy after surgery. While these blood tests are not yet perfect, they offer hope in the fight against cancer.
Source: https://katiecouric.com/health/cancer/benefits-of-ctdna-blood-testing-for-cancer