Breaking new ground in the fight against cancer

With innovative cancer screening tests now available, care may be revolutionised for millions of patients

When a friend developed cancer some 20 years ago, biochemist Randy Scott began exploring the potential of genomics, the study of genes, to understand the disease. He developed the ground-breaking Oncotype DX tests designed to transform treatment decisions of certain cancers1. More than a million people worldwide have now received the Oncotype DX test2.

Breast cancer

Central to the genomics revolution transforming cancer care, Oncotype DX testing, among other things, identifies gene expression in cancer cells3,4. Take breast cancer for example. So-called adjuvant, or additional, therapy is a key part of treatment. This can include chemotherapy after surgery when there may be uncertainty about whether or not the operation has totally eradicated the tumour5.

The problem is that not all women benefit from chemotherapy6. Dr Richard Simcock, who has been a consultant clinical oncologist at the Sussex Cancer Centre since 2004, says: “We can now more accurately predict which women are going to benefit. The Oncotype DX test helps reduce the guesswork. More importantly, I can identify those women who are not going to benefit, sparing them the toxicity of chemotherapy.”

Chemotherapy side effects include fatigue, nausea and hair loss7. It is not only patients who benefit from this transformational advance. A recent study by the East Anglia Medical School reported that chemotherapy costs the NHS more than £248m per year8.

What surprised researchers and doctors was the scale of the impact of the Oncotype DX test. In a landmark trial with 10,000 patients in the US, Canada, Ireland and South America, reported in The New England Journal of Medicine, researchers found that 70% of women with the most common type of breast cancer show no benefit from chemotherapy9.

The Oncotype DX breast cancer test is not like a genetic test that maps a person’s genetic profile. The National Institute of Health and Care Excellence (NICE) explains: “It looks at genes in a patient’s breast tumour to understand how these genes interact and influence the tumour’s behaviour10.” This is critical because every tumour is unique: the more doctors know about each one, the more likely they are to be able to treat it effectively.

Marketed by a world leader in cancer diagnostics, Exact Sciences, the breast cancer test is part of an extensive portfolio of tests aiming to enable the delivery of personalised care across the cancer continuum.’

Colon cancer

Exact Sciences’ products include Cologuard, a stool DNA-based colorectal cancer screening test for average-risk individuals who are 45 or older. Detecting disease at an early stage when it is easier to treat, Cologuard analyses stool samples for 10 genetic markers and blood in the stool. Reported to have been used by more than 8 million people, the sample collection is carried out in the privacy of people’s homes11.

People do get ‘wowed’ by the science, but what we’re trying to do is to provide sufficient information to enable patients and physicians to make informed decisions about their treatment approach and likely outcome

Minimal residual disease

Exact Sciences is developing a test to identify so-called ‘minimal residual disease’ (MRD), which are cancer cells that remain in the body after treatment. The number of such cells may be so small that they do not cause any physical signs or symptoms.

Any remaining cancer cells in the body can become active and start to multiply, causing a relapse of disease. Detecting MRD from a blood sample may indicate that the treatment was not completely effective or that the treatment was incomplete or that the cancer cells became resistant to the medications used. Exact Sciences estimates that such information may be used to guide adjuvant therapy decisions and/or to monitor cancer recurrence, in conjunction with other clinicopathological findings, providing more than 12 million testing opportunities in the US alone.

Multi-cancer early detection

Too often, cancer is detected too late. Current screening can find some types of cancer – breast, colon, cervical and lung – but these make up less than a third of all cancers13. Exact Sciences is developing a new kind of blood test, Multi-Cancer Early Detection (MCED), to detect cancer early, when it is at its most treatable stage.

In future, MCED tests may become as standard as routine blood pressure testing and identify cancer in millions of patients long before symptoms occur. They may even consign late cancer detection to history.

Exact Sciences is further developing the MCED test originally developed by Thrive Earlier Detection, one of eight companies it has acquired in the last three years to position itself as a leader in the rapidly expanding world of genomics cancer testing.

In 2020, Thrive and researchers from Johns Hopkins University announced that a multi-cancer blood test used to screen more than 9,000 women had detected 26 undiagnosed cancers12.

Working across the cancer continuum

Transforming cancer outcomes requires a comprehensive suite of tests and treatments for all patients before, during, and after a diagnosis. Exact Sciences’ vision is to fuel the future and advance cancer care for patients at all stages of the disease, working with others to put all these pieces together and into action.

Hereditary cancer assessments will give as many people as possible the power to know their personal risk for cancer screening tests for more cancers so they can be detected early when they are more treatable. Therapy guidance tests to help patients and health care providers select the right course of treatment for their specific cancer and to avoid over-and under-treatment.

Minimal residual disease testing is currently in development and is designed to assess whether a treatment has removed the cancer and monitor whether the cancer is coming back on a highly personalised, cancer-by-cancer basis.

Personalised versus precision medicine

The pace of scientific progress is dazzling, but Simcock stresses that traditional holistic care is as important as ever. He says: “I think that some people conflate ‘personalised’ medicine’ with ‘precision medicine.’ Making a clinical decision purely on the basis of whether a person has a particular mutation is not very personal. It should not distract us from the holistic care of that individual. The key here is not what is the matter with them but what matters to them. But we need precision medicine to deliver ‘personalised’ medicine.”

Andrew Paramore, director of medical affairs at Exact Sciences, agrees. He says: “People do get ‘wowed’ by the science and references to ‘personalised’ and ‘precision,’ but what we’re trying to do is to provide sufficient information to enable patient and physicians to make informed decisions about their treatment approach and likely outcome.”

To find out more, please visit

  1. Exact Sciences. [Online] July 2022.
  2. Exact Sciences. Over 1 Million Patients Tested; Data Onfile. 2019.
  3. A Multigene Assay to Predict Recurrence of Tamoxifen-Treated, Node-Negative Breast Cancer. Paik, S, Shak, S and Tang, G. 27 , 2004, NEJM, Vol. 351, pp. 2187- 2862.
  4. Gene expression and benefit of chemotherapy in women with node-negative disease, estrogen recpetor -postive breast cancer. Paik S, Tang, G, & Shak S et al. 23, 2006, Journal of Clinical Oncology , Vol. 24, pp. 3726-3734.
  5. Breast Cancer Now. Chemotherapy. [Online] [Cited: July 14th, 2022.]
  6. Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100 000 women in 123 randomised trials. (EBCTCG), Early Breast Cancer Trialists’ Collaborative Group. 2012 , Lancet 2012; 379: 432–44, Vol. 379, pp. 432- 44.
  7. Side effects of chemotherapy and combined chemohormonal therapy in women with early-stage breast cancer. Partridge, A H, J, Burstein H and P., Winer E. 2001, J Natl Cancer Inst Monogr, pp. 135-142.
  8. Societal costs of chemotherapy in the UK: an incidence-based cost-of-illness model for early breast cancer. Krishnali Parsekar, Stephanie Wilsher, Anna Sweeting, et al. 2021, BMJ Open.
  9. Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast Cancer. JA Sparano, R J Gray, DF. Makower, et al. 2018, N Engl J Med, Vol. 379, pp. 111-121.
  10. Tumour profiling tests to guide adjuvant chemotherapy decisions in early breast cancer.
  11. Exact Sciences. [Online] Exact Sciences. [Cited: July 14th, 2022.]
  12. Feasibility of blood testing combined with PET-CT to screen for cancer and guide intervention. Lennon AM, Buchanan AH, Kinde I, et al. 6499, 2020, Science, Vol. 369.
  13. PleSiegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2022. CA Cancer J Clin. 2022;72:7-33ase

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