Early Detection: A New Front in the War on Cancer

Half a century after the original War on Cancer, cancer’s personal, societal, and economic burden remains high. One critical element to reduce this burden is the development of effective early detection technologies.

This requires a better understanding of the biology and trajectory of precancer and early cancer to distinguish the consequential disease from inconsequential lesions that do not require intervention. New blood-based multi-cancer early detection (MCED) technologies hold promise for changing the way we screen for cancers.

Advances in Detection

Over the past four decades, significant improvements have been made in the basic science and clinical approaches to detecting cancer early. These advances, combined with an increased understanding of the biological mechanisms and progression of cancer, have led to several new detection methods, including liquid biopsy techniques that use noninvasive sampling and molecular analysis to detect and monitor tumors.

In comparison to traditional imaging and tissue biopsy-based pathology, these methods are relatively low in invasiveness, faster, and simpler. They may also reduce false positives, a significant limitation of current screening strategies.

These new methods are being developed to be used across the body and simultaneously detect multiple types of cancer. This is important because a person whose cancer is detected before it spreads to other parts of the body is more than four times as likely to survive for five years as a patient with metastatic disease.

However, the development of these multicancer tests is not without challenges. For one, it’s difficult to know when a test is accurate enough to save lives. It’s also important to balance the benefits of these tests with other healthcare needs, such as keeping people healthy and avoiding overscreening. The US Preventive Services Task Force (USPSTF) recommends that individuals over age 50 seek regular cancer screening only when the benefits outweigh the harms of overscreening, such as the risk of false positives.

Challenges in Implementation

In a cancer screening context, the challenge is that it can take decades to get a new early detection test into the hands of the general public. This is largely due to the need for adequate research and for the healthcare system to adjust coverage and reimbursement to support this work.

Another challenge is that, as our understanding of cancer biology has evolved from histologic stratification to genetic subtyping and tumor heterogeneity within single cancer, we have come to recognize that not all cancers are equal.

Some are much more likely to progress and spread. Others are more likely to respond to therapeutics. MCED approaches must be attuned to identifying the more lethal cancers so that they do not indiscriminately detect indolent cancers that are unlikely to cause the kind of harm that patients would die from.

Lastly, women with low incomes or in remote areas may have trouble accessing the services necessary to make early detection possible. This is especially true if the providers they see do not have sufficient training and experience in recognizing early breast cancer or do not know where to refer a patient who might have a potentially symptomatic abnormality.

Boosting National Institutes of Health funding for cancer detection and diagnosis research can go a long way toward narrowing this gap, but it will also require that we rethink how we deliver these services to the populations most in need. Providing access to these technologies through community health workers is one strategy.

Costs of Implementation

Cancer is a major burden on health care systems, but it can be prevented or detected early by routine screening examinations. In addition to reducing cancer incidence and mortality, early detection reduces the personal, societal, and economic costs of cancer. The challenge is to implement early detection strategies that deliver transformative results, as measured by improved survival and quality of life.

This requires combining germline genomic susceptibility, family history, exposures, and demographic factors to develop nuanced risk models that determine who should be screened and what results mean for diagnosis, treatment, and follow-up.

Moreover, effective cancer prevention strategies require a commitment to the belief that individuals can have an impact on their long-term fate—which must be supported by the elimination of structural barriers to prevention, such as poverty and low educational attainment.

Finally, a key challenge is to translate the rapidly evolving biological insight into new diagnostic technologies and clinical trials that can be deployed in real-world settings. This requires broader skill sets that include engineers, physicists, technology developers, and social scientists—and integrated, interdisciplinary collaboration.

As we continue to make significant progress in detecting cancer at earlier stages, the time is now for a major shift in how we approach the fight against this deadly disease. Ultimately, a paradigm shift in the way we combat cancer will save lives and decrease the personal, societal, and economic costs associated with it.

Impact on Quality of Life

Cancer detection methods aim to find precancerous lesions and early-stage cancers before symptoms appear. They then provide healthcare providers with information about these abnormalities so that they can monitor or surgically remove them before they progress to a more dangerous stage.

These efforts are important because people who receive cancer screening and early diagnosis are more likely to survive and experience a better quality of life compared to those diagnosed later. Earlier diagnoses have also been associated with less treatment-related morbidity and lower costs of care.

However, reducing disparities in the uptake of cancer screening requires a comprehensive strategy that includes interventions to address barriers and ensure access. For example, research has shown that social-economic status (SES) plays a significant role in whether people with potentially terminal illnesses seek preventative and early-detection services. This includes cancer screening, where people of lower SES are more likely to report insufficient knowledge and barriers to accessing care.

A key obstacle is that there are currently only a few broad-based cancer screening tests available to asymptomatic patients. For instance, in the U.S., screening for breast, cervical, colorectal, and lung cancers for a high-risk subset of the population is recommended, but other cancers that are associated with higher mortality rates do not have routine screening recommendations (see sidebar on How Are Cancer Screening Guidelines Developed). Additionally, some individuals receive unnecessary screening tests due to overscreening.