The shifting cancer landscape involves an increase in early-onset cases among those under 50, in addition to the age-related risk. With regular screening to detect cancer early as the mainstay of preventing the disease, multi-cancer early-detection liquid biopsy tests are making their way as a cancer screening because of their higher detection sensitivity. Dr. Tan Min Han, a medical oncologist and the Medical Director of Lucence, provides further insights into this development.
Cancer can be considered an age-related disease due to the incidence of many cancers increasing sharply as individuals enter middle age, regardless of gender. That having said, cancer does not have to be an inevitable consequence of aging. Earlier cancer detection before symptoms arise allows for earlier intervention, and even a potential cure.
Singapore's aging population, coupled with the urban lifestyles of the younger generation, raises concerns about a potential surge in cancer cases in the coming years. Local oncologists have already seen an increase in younger adult patients seeking treatment.
While modern targeted treatments and immunotherapy have shown promise in some cases, early cancer detection allows patients to enjoy a better quality of life. However, focusing solely on treatment advancements is insufficient to tackle the cancer burden, including the financial costs of treatment and caregiving. It is imperative to view cancer not only as a treatable but also as a preventable condition through regular screening and early detection.
"The earlier cancer is detected, the less invasive and the less painful treatments are going to be,” Dr. Tan said.
Treatment of earlier-stage cancer leads to better outcomes and fewer long term side effects, compared to treatment of late-stage cancers which involve expensive drugs and palliative care.
While screening programs have improved cancer survival rates, there are challenges in making them even more effective and less invasive. Some methods, such as low-dose CT and mammography to detect lung and breast cancers can lead to overdiagnosis, false positives and unnecessary radiation exposure. Similarly, screening for prostate cancer using serum PSA testing has its limitations. On the other hand, colonoscopy is highly accurate for colorectal cancer detection, but it is invasive and uncomfortable.
Besides imaging and procedures to pick up abnormal tissue growth and polyps, blood tests are another screening test to detect tumor markers. It is pivotal in early cancer detection, diagnosis, and treatment. But there are limitations.
While some cancers, like prostate cancer, remain asymptomatic in their initial stages, these markers can also be elevated in patients without cancer1, leading to false-positive and unnecessary follow-up tests and treatments.
Some tumor markers may be unique to a particular type of cancer, whereas others may be linked to multiple types of cancers. There are also cancers with no known tumor markers2.
“Tumor markers, while remaining a standard in cancer screening, has a risk of low specificity that produces false positives. These false positives lead to patients’ anxiety, an impact on their insurance coverage and further invasive investigative procedures,” Dr. Tan said.
In some patients, tumor marker levels don't go up until the cancer worsens, making it harder to diagnose cancer in its early stages.
Hence, there is a need for innovative, accurate, and minimally invasive tools for early cancer detection. Multi-cancer early detection (MCED) tests have emerged as a screening tool, capable of detecting a range of cancer signals with high specificity3.
“The high specificity of these tests will enable even earlier detection of a much broader range of cancers, so patients benefit from early treatment and have a better chance of a cure,” he added.
“To a cancer patient, time is precious and it’s important to understand quickly what the best treatment option is for a patient. No one wants to have to undergo two months of expensive therapy, to find that it wasn’t the right option,” he said.
MCED test is still a blood test, but now it combines DNA molecular analysis of tumor-related markers with artificial intelligence to simultaneously detect the presence of cancer.
Cancer happens when gene changes make cells grow uncontrollably. These cells release circulating tumor DNA (ctDNA) into the blood, which the MCED test amplifies and detects. Using machine learning, it analyzes the cancer signal profile and identifies the ctDNA's possible source. This includes breast, lung, colorectal, nose, liver, pancreas, prostate, bile duct and blood cancers. Localized treatments with surgery and radiation therapy can then follow to treat a specific tumor or area of the body.
MCED tests are shifting the cancer screening approach from single organ checks to multi-organ testing with a single blood sample.
“We develop MCED liquid biopsies or blood tests, to achieve earlier cancer detection and better treatment selection. Today, these blood tests are most useful for patients whose cancers are difficult to biopsy. These include lung cancer, gastrointestinal cancer, as well as cancers that are widely metastatic, such as breast or prostate cancers that have metastasized to bone,” Dr. Tan explained.
A liquid biopsy is a blood test that detects cancerous tumors by finding pieces of tumor cells and DNA in your bloodstream. Like a regular biopsy, which directly tests tumor tissue, liquid biopsies provide evidence of a tumor and genetic information about it.
“Cancers that are difficult for physicians to diagnose, will need tissue biopsies to identify the presence of cancer. These procedures are invasive, painful, and risky. Getting that same information from a blood test is a far better option,” he added.
In medicine, screening tests are assessed based on their sensitivity and specificity.
Sensitivity checks if the test can accurately spot the condition it seeks without missing real cases (no false negatives).
Specificity checks if the test can correctly identify people without the condition, avoiding false alarms (no false positives).
Dr. Tan’s medical lab, Lucence, has been researching and developing enhanced liquid biopsy technology since it was founded in 2016. At the 59th Annual ASCO Meeting in Chicago, June 2-6, 2023, Lucence shared data on a multi-cancer screening test that looks for mutations in ctDNA using its unique sequencing technology. They tested it on 613 people and found a sensitivity of 72.7% (finding cancer-related changes) and a specificity of 98.6%. They also used a personalized algorithm which includes clinico-demographic information such as gender and age to predict where the cancer came from.
“Liquid biopsies are making a big difference to cancer patients in terms of early detection and treatment decisions. It can be considered for individuals at elevated risk, particularly those who are concerned about cancers not traditionally screened for. Age thresholds that have been proposed include above age 40,” he advised.