Innovations in cancer prevention, diagnosis, and management over the past decade have given significant hope for those living with cancer. Yet, there still exists a sharp divide between resource-rich nations and the low- and middle-income countries (LMICs) where the cancer survival rate is far lower. Seventy-five percent of all cancer deaths occur in LMICs where cancer is often diagnosed in a late stage.1
The good news is that there is promising new technology on the horizon. An early stage multi-cancer screening that could be used for cancer screening in LMICs which have limited resources, is in development, according to ASCP Chief Medical Officer Dan Milner, MD, MBA, FASCP. “These assays could be a game changer for low- and middle-income countries,” he says. “Even a flawed test that is 75 percent effective is better than what some of these countries currently have.”
In January, Dr. Milner attended an international universal cancer screening summit, hosted by the Mayo Clinic Cancer Center, the American Cancer Society, and the Union for International Cancer Control in Rochester, Minnesota. Participants included oncologists, surgeons, industry leaders, venture capitalists, and one pathologist—Dr. Milner.
Attendees explored implications of recent advances in cancer biology, biomarker discovery, and laboratory methodology which could transform cancer prevention and control through earlier detection via a multi-organ screening approach. Seven teams, comprised of participants at the summit, developed articles addressing myriad issues pertaining to the development of a multi-organ screening approach.
Dr. Milner served on a panel that drafted a commentary titled, “International perspectives on the development, application, and evaluation of a multi-cancer early detection strategy,” published February 15, 2022, in Cancer magazine. The topics examined in the commentary include:
the challenges experienced by most LMIC settings that have screening and early diagnosis systems in place;
places where the introduction of a multi-cancer early detection test could have the greatest impact on transforming cancer care;
the opportunities and challenges related to implementation of a multi-cancer early detection assay that could function as a universal cancer test; and,
key considerations relevant to the international setting.
Currently, around the globe, cancer prevention and early detection are considered key components of a cancer control strategy; they are also cost-effective. Nonetheless, there are some cancers that present symptoms at later stages and for which early screening would not be effective. These cancers, including pancreas, esophagus, ovaries and stomach, are more complex and do not always respond well to treatment.
The specific types of cancer experienced by populations vary globally with higher incidence of cancers related to infections in LMICs. The article recommends that some countries should consider implementing screenings for certain types of cancer. In Asia, for example, the prevalence of gastric cancer is high enough that endoscopic screening can be recommended to identify individuals who have precancerous histologic changes in the stomach and those who have Helicobacter pylori, a carcinogenic agent that can be treated with antibiotics to reduce the risk for malignant transformation.2
But the implementation of screenings for early detection of cancer, by itself, is not enough to reduce mortality. Timely follow up and stage appropriate treatment are also necessary. “Therefore, whether a multi-cancer early detection test would lead to a reduction in mortality for low-prevalence and rare cancers would depend on the availability and effectiveness of treatment for those cancers,” the article’s authors write.
The implementation of a multi-cancer early detection test in a low-income country may still seem to be a stretch. However, the authors note that cancer diagnostics and treatment in LMICs have greatly benefited already from advances in liquid biopsies and next generation sequencing. The article cites cervical cancer as an example of a cancer that has benefited from next generation sequencing which has resulted in new diagnostic tools to test HPV genotypes, which are linked to cervical cancer.
Currently, in many LMICs, patients must travel to a specialized cancer center, frequently located in a city, and incur numerous visits for assessments including fine needle aspiration or core biopsy and imaging tests. Just scheduling the visits can take several weeks, thus delaying treatments. It’s also very expensive.
“Decentralizing screening for any cancer to include the test at point-of-care (POC) would be [a] transformative [innovation], and if the test is multi-cancer-focused, it may be [a] disruptive [innovation],” the authors write. Transformative innovations quickly sweep a system and become the new gold standard, while disruptive innovations present an entirely new approach that makes old systems obsolete. Since these cancer detection systems do not exist in most LMICs traditionally (for example, widespread mammography and colonoscopy are lacking), blood-based multi-cancer early detection (MCED) tests for many cancers would be a disruptive innovation.
A hub and spoke model—anchored by a tertiary hospital or cancer center with a full array of services, connected to satellite centers, could be created to provide services to a geographically defined service area in LMICs. Using this model, a point-of-care approach to providing the MCED could allow testing to be done a primary health care or secondary-level health facilities. Patients requiring more intensive treatment could then be referred to a tertiary hospital for follow up.
“Many patients with cancer in LMICs frequently present at relatively late stages,” Dr. Milner says. “The (MCED) test can also serve as a multi-cancer diagnostic; that is, patients with a demonstrable mass could still benefit if time-value, cost, and treatment plan alignment are considered in the integrated care pathway.”
Implementing a universal cancer test may have a different approach in various nations, depending on the capacity of their respective health systems. A short-term goal identified by Dr. Milner and his co-authors is to define how to conduct the necessary clinical trials in these nations to generate the local data needed for adoption. This is especially so in LMICs where a lack of financial and human capacity, and ethical and regulatory barriers make it challenging to conduct clinical trials.
What needs to happen first is strengthening laboratory services in LMICs before innovations in cancer screening and diagnostics can occur.
At the country level, laboratory strengthening and the integration of services are likely to have a significant impact on patient outcomes by enabling existing laboratories to provide cancer testing and thus giving more patients access to a diagnosis.
In closing, the authors wrote, “Despite several implementation challenges highlighted in this commentary, we believe that an MCED strategy is worth pursuing for international applications because of the potential for substantially positive impacts on population-level cancer statistics and the patient-level cancer experience. The current situation in LMICs for cancer screening and testing remains challenging. We recognize that there is no blueprint or one-size-fits-all strategy for the introduction of an MCED test internationally because health systems, the epidemiology of cancer, and the stage presentation of cancer disease are very different in countries and regions.”
Sonali E. Johnson, BA, MSc, PhD, et al. International perspectives on the development, application, and evaluation of a multi-cancer early detection strategy. Cancer, Feb 15, 2022, pg. 877.
2. Sonali E. Johnson, BA, MSc, PhD, et al. International perspectives on the development, application, and evaluation of a multi-cancer early detection strategy. Cancer, Feb 15, 2022, pg. 878.