False Positives in Cancer Screening Tests: A Concerning Trend in Japanese Start-up's Products

Cancer screening tests play a crucial role in early detection and prevention of cancer. They help identify individuals who may be at risk and enable timely intervention. However, a recent report highlights a concerning trend related to cancer screening tests sold by a Japanese start-up. According to some doctors, a significant number of cancer-free individuals have tested positive on these tests.

The Issue at Hand

The Japanese start-up’s cancer screening tests have gained popularity due to their accessibility and affordability. These tests utilize advanced technologies to detect cancer biomarkers in blood or other samples. While they have been successful in detecting cancer in many cases, there is growing evidence suggesting a high rate of false-positive results.

Doctors who have reviewed the test results of their patients are expressing concern about the potential harm caused by inaccurate diagnoses. False-positive results can lead to unnecessary anxiety, additional invasive diagnostic procedures, and increased healthcare costs. Moreover, false positives may divert medical resources from individuals who truly need attention.

Possible Explanations for False Positives

Understanding the reasons behind these false positives is essential to address the issue effectively. There could be several factors contributing to the problem:

  • Lack of specificity: The tests may not be specific enough, leading to the detection of biomarkers that are not exclusively associated with cancer. Cross-reactivity with other substances or conditions could be responsible for the false positives.
  • Inaccurate reference ranges: The reference ranges used to determine whether a test result is positive or negative may not be appropriately established. Flawed reference ranges can result in an increased number of false positives.
  • Technical errors: Issues related to sample handling, laboratory techniques, or equipment calibration could also contribute to false-positive results. Quality control measures need to be stringent to minimize these errors.

The Future of Cancer Screening Tests

Despite the concerns raised about false positives, the field of cancer screening tests continues to evolve rapidly. Significant advancements in technology and research provide hope for a future where accurate and reliable tests are widely available.

The key trends emerging in the industry include:

  1. Improved specificity: Efforts are being made to enhance the specificity of cancer screening tests. The development of novel biomarkers that are highly specific to certain types of cancer holds promise. Additionally, advancements in machine learning and artificial intelligence can aid in refining the algorithms used to analyze test results, reducing the incidence of false positives.
  2. Multi-modal approaches: Combining multiple screening methods, such as imaging techniques and liquid biopsy, can enhance the accuracy of cancer detection. Integrating various modalities into a comprehensive screening approach could help overcome the limitations of individual tests and minimize false positives.
  3. Personalized screening: The future of cancer screening lies in tailoring the tests according to an individual’s genetic and lifestyle factors. By considering specific risk factors, such as genetic mutations or exposure to carcinogens, screening tests can be optimized for each person, increasing accuracy and minimizing false positives.

Recommendations for the Industry

To address the issue of false positives in cancer screening tests, the following recommendations can be considered:

  1. Regulatory oversight: Regulatory bodies should establish stricter guidelines for the development and approval of cancer screening tests. These guidelines should emphasize the importance of specificity and accuracy, ensuring that false-positive rates are minimized.
  2. Collaborative research: Collaboration between start-ups, research institutions, and healthcare providers can facilitate the identification of novel biomarkers and advancement of screening technologies. Sharing knowledge and resources can accelerate progress in the field.
  3. Transparency and education: It is crucial for companies selling cancer screening tests to provide transparent information about the limitations and potential risks associated with their products. Patients need to be educated about the meaning of test results and the probability of false positives, empowering them to make informed decisions.


The issue of false positives in cancer screening tests sold by a Japanese start-up raises concerns about the accuracy of these tests. However, this challenge presents an opportunity for the industry to make improvements and advance towards more reliable and effective screening methods. With continued research, technological advancements, and regulatory oversight, the future holds promise for accurate and personalized cancer screening tests that can contribute to better healthcare outcomes.

Reference: Nature, Published online: 20 December 2023; doi:10.1038/d41586-023-03733-9