Could Liquid Biopsies Be The Holy Grail in Cancer Diagnostics?

Next generation genetic tests aim to provide cancer diagnostics at a very early stage, potentially saving millions of lives per year and generating hundreds of billions in revenue. Given the pace of improvement in their specificity and reliability, molecular diagnostic tests could make more progress against cancer in the next decade than have all the advances in this fight during the last fifty years. The premise is simple. Roughly 59% of cancers go undetected until they metastasize (spread);[1] therefore, if a genetic blood test could identify these neoplasms locally, when they are contained entirely to the organ of origin,[2] then, as shown below, almost half of deaths due to cancer today could be avoided using existing therapeutic regimens.

Several companies are at the forefront of cracking the code to cancer at an early stage. Illumina [ILMN], for example, is responsible for more than 90% of all the base pairs of DNA sequenced in the world today. An Illumina spinout, GRAIL aims to provide early detection of cancer with a blood screen, commonly known as a “liquid biopsy.” The biopsy will be a “pan-cancer” screening test measuring nucleic acids circulating in the blood. GRAIL’s goal is to decrease global mortality by detecting cancer at a curable stage. According to a recent Illumina investor presentation, if cancer were to be detected routinely at Stage 1, GRAIL could capitalize on a ~$100 – $200 billion market opportunity.[3]

According to ARK’s research, the market for early stage cancer diagnostics (CDx) could be multiples of $200 billion. Historically, health systems have reimbursed tens of thousands of dollars for a year of extended life. Because early cancer diagnostics would potentially save millions of life years globally, the total available market for such an advance could exceed $1 trillion.

ARK believes that if all cancer diagnoses took place during Stage 1 instead of Stages 2 to 4, lifespans would be lengthened by 2.9 years on average, as illustrated below.

Based on the historical average life expectancy of US cancer patients from 1975 to 2008, and extrapolating through to 2016, therapy advances have added approximately 1.5 years of life post diagnosis per decade. From 1975 to 2016, the average lifespan of a cancer patient increased by approximately 5.5 years. Remarkably, by diagnosing cancer in Stage 1, GRAIL could deliver over half of that advance almost immediately, increasing the average life expectancy of 65 year olds with cancer to 80.6 years, as shown below. At the historical rates of therapeutic advances, that life expectancy would not occur until approximately 2035.

The cancer community would be quick to point out, and ARK would agree, that early cancer diagnostics procedures—such as colonoscopies to screen for precancerous lesions (polyps)—already have improved prognoses dramatically. Others in the space are competing to achieve early diagnostic precision as well. For non-high-risk cases, Exact Sciences’ Cologuard is screening for cancer through a noninvasive test administered at home, using stool samples. While identifying 92% of cancers and 42% of pre-cancers, Cologuard is less specific than the standard of care, a colonoscopy.[4] Someday if liquid biopsies could identify precancerous lesions with a level of accuracy equal to a colonoscopy, blood tests could take the place of colonoscopies.

While we recognize that our estimates are rough and could overstate the case, GRAIL and liquid biopsies could revolutionize the cancer landscape. Of particular importance, Stage 1 screening could take place during routine physicals each year. Even without an improvement in cancer therapeutics—like the promises associated with immunotherapy or gene-editing— earlier cancer diagnostics could reduce effective cancer mortality by almost half.