Multi Cancer Early Detection Testing: Promise and Challenges

Cancer remains one of the most significant public health challenges globally, accounting for nearly 10 million deaths each year.¹ Still, only a handful of cancer types have recommended routine screening. Because the success of cancer treatment often depends on how early the disease is detected, effective screening strategies are paramount.

Traditional screening methods are largely cancer‑specific, such as mammography for breast cancer, colonoscopy for colorectal cancer, Papanicolaou test for cervical cancer, prostate-specific antigen test for prostate cancer, skin exams, and low-dose CT scan for lung cancer. However, these screening methods are limited in coverage and access.

In response to the need for early and improved screening, an emerging technology known as multicancer early detection (MCED) tests seeks to detect multiple cancer types from a single blood draw. By analyzing circulating tumor DNA, methylation patterns, or protein markers, MCED tests hold enormous promise for improving clinical outcomes through early intervention.² Despite this potential, MCED testing has significant pros and cons.

Pros of MCED Testing

1. Earlier Detection and Improved Survival

The advantage of MCED testing is its potential to identify cancers at earlier, more treatable stages; detecting cancer even one stage earlier can reduce mortality. For cancers with rare early symptoms, such as pancreatic, ovarian, and esophageal cancers, early detection via blood test may dramatically improve survival rates.

2. Comprehensive Screening

MCED tests provide a multiorgan approach. A single blood sample can assess risk across more than a dozen cancer types.² This ability could improve screening adherence by being less invasive and reducing costs to the health care system. With proper implementation, MCED testing could improve access to rural and underserved populations where traditional screening is limited. There is significant potential for health care equity if MCED proves accessible to all populations, especially in financially challenged areas.

Cons of MCED

1. False Positives and Overdiagnosis

One major limitation of MCED technology lies in its accuracy. Although specificity is improving, false‑positive results remain a concern.³ Will false positives cause unnecessary follow‑up imaging, biopsies, or procedures that lead to increased cost and possible emotional distress? What happens to the detection of indolent tumors that may never progress? What are the ethical considerations about treating these patients? Clinicians must remember: “First, do no harm.”

2. Economic and Systemic Burden

Currently, MCED tests are expensive, with some marketed versions costing more than $900 per test.⁴ Large‑scale screening programs would place financial strain on health care budgets, especially if follow‑up diagnostics are necessary. Therefore, MCED assays will require careful considerations, focusing on high‑risk populations before expansion.

3. Research Gaps

Although results of early clinical studies are promising, long‑term data on MCED’s ability to reduce overall cancer mortality remain limited. Major MCED tests still miss 85% of stage I tumors, depending on the cancer type.⁴ Regulatory agencies, including the FDA, continue to emphasize the need for rigorous clinical validation before routine use.

4. Ethical and Privacy Considerations

MCED tests involve the collection of sensitive genomic data, raising concerns about patient privacy and data security. Storage, sharing, and secondary use of genetic information must comply with strict privacy legislation. Policy makers and clinicians will need clear guidelines to manage these complex ethical issues.

Conclusion

MCED tests represent a major technological leap in oncology, reflecting the ongoing shift toward personalized and predictive medicine. The potential for earlier detection, improved survival rates, and enhanced accessibility justifies optimism about their future integration. However, unresolved challenges—including test accuracy, affordability, clinical validation, and ethical governance—must be carefully addressed to ensure equitable and responsible use. With careful, precise evaluation and evidence‑based implementation, MCED testing could usher in a new era of proactive, inclusive cancer care.

References

1. Cancer. World Health Organization. February 3, 2025. Accessed January 22, 2026. https://www.who.int/news-room/fact-sheets/detail/cancer
2. Liu MC, Oxnard GR, Klein EA, Swanton C, Seiden MV; CCGA Consortium. Sensitive and specific multi-cancer detection and localization using methylation signatures in cell-free DNA. Ann Oncol. 2020;31(6):745-759. doi:10.1016/j.annonc.2020.02.011
3. Cohen JD, Li L, Wang Y, et al. Detection and localization of surgically resectable cancers with a multi-analyte blood test. Science. 2018;359(6378):926-930. doi:10.1126/science.aar3247
4. Sempere LF. Ethical considerations and implications of multi-cancer early detection screening: reliability, access and cost to test and treat. Camb Q Healthc Ethics. 2025;34(3):489-498. doi:10.1017/S0963180124000744