Regardless of location, few people have escaped being touched by cancer and infectious
diseases. Since the COVID-19 pandemic began, the world has a new-found respect for
infectious diseases threats; people everywhere on the planet already had an awareness
and substantial fear of cancer.
The relationships between infectious diseases and cancer are clear, although we have
a lot to learn. Potential vaccine-mediated prevention of >90% of cervical cancers
arising from the recognition of human papillomavirus (HPV) oncogenicity [1], as well
as the impact of prevention and management of hepatitis B and C viral infection on
dramatically reducing hepatocellular carcinoma burden [2, 3], are the most striking
examples of the value of exploring such linkages. Helicobacter pylori and gastric
cancer [4], Schistosoma haematobium and bladder cancer [5], Epstein-Barr virus and
Burkitt’s lymphoma [6], and Human Herpesvirus 8 (HHV8) and Kaposi’s Sarcoma [7] are
other notable examples.
Simplistically, infections trigger cancers through chronic inflammation of the tissues
they infect, creating the potential for oncogenic mutations in those tissues, but
there are multiple processes that contribute at cellular, interstitial, immunologic,
vascular and molecular levels, as well as co-factors with innate host characteristics,
environmental exposures, especially radiation and toxins, and potentially additional
pathogens or pathogen-related substances.
Infections and oncogenesis have been characterized with a sufficient number of cancers
to wonder whether we are, thus far, just scratching the surface. Upon receiving the
Nobel Prize for his work on HPV and cervical cancer in 2005, Harald zur Hausen predicted
more discoveries in this field—he was correct—and research efforts on infectious diseases
and cancer did expand.
At least 800,000 new cancers were estimated for Africa in 2020 with >500,000 deaths,
likely underestimated because of limitations in diagnostics and reporting; by 2040,
1.5 million new cases and one million deaths are projected [8]. Cancer prevention,
detection, and management in sub-Saharan Africa are decades behind what exists in
high-income geographies. These inequities, coupled with the substantial and rising
cancer burden, serve as a clarion call for action. In response, we are building a
network for sophisticated and collaborative infectious diseases and oncology research
and basing it in sub-Saharan Africa. The goal of research and programs will be to
produce innovative, effective, yet practical diagnostics, preventatives, and therapeutics
that are designed for use in sub-Saharan Africa, and may also have global application.
Scientists in cancer and infectious diseases disciplines use sophisticated, expensive
tools to advance the science. But, they typically operate in silos—clinicians and
scientists in the two arenas seldom interact. We will make the case for changing that
to accelerate impactful advances.
While there are an estimated 2.2 million infection-attributable cancer cases occurring
each year globally [9], that figure is based on what is currently known. Why is there
not a discipline of infectious oncogenesis? Perhaps if infectious disease and cancer
immunologists, biologists, clinicians and epidemiologists were thinking, innovating
and working together there might be unexpected and exciting discoveries bringing about
an accelerated pathway towards new clinical tools. Collaborations would take such
findings to the next level, developing diagnostics, prevention approaches like vaccines
or novel methods, and therapies. An ideal end to end framework would include downstream
processes for working with industry, advisory groups, regulatory agencies, Ministries
of Health, civil society, and other stakeholders to move effective products, like
early diagnostics and vaccines, into use, energizing the “discovery to action” timeline.
Are there additional infection-associated cancers that would make such a collaborative
union worthwhile? To answer with a question, given that there is solid evidence for
a significant relationship for six cancers already, why would we think that there
are no more to be discovered using systematic approaches? There are evidence-based
hypotheses to support infectious facilitation of development and outcomes for prostate,
breast, colorectal cancer to name a few [10–12]. Importantly, the search for infectious
disease linkages with cancer should not be limited to viruses and bacteria. The relationship
between aflatoxin and liver cancer is already well described, and fungi and their
products (i.e. mycotoxins) might stimulate chronic inflammation, facilitating carcinogenesis
in the case of esophageal cancer [13]. The collaboration will be attentive, as well,
to the potential impact of climate change on the geographic scope and magnitude of
oncogenic pathogens and associated toxins, as well as the effect of climate change
on access to timely diagnoses and care for infectious diseases and cancers.
It is also likely that absence of infectious agent(s) increases risk for certain cancers.
If, for instance, the respiratory, gut, skin or other microbiome is absent a particular
bacterium or diversity of bacteria, might that leave an organ prone to other carcinogenic
stimuli? The diversity of organisms, especially bacteria and fungi, within tumors
has been a growing topic for study [14]. Immunologic responses to infectious diseases
in the context of tumor development will also need to be assessed.
What if there was an expectation of detecting infectious facilitators for a specific
cancer? When a connection is shown, algorithms would be activated for a) defining
the importance (i.e. what proportion of cancers in what populations are associated
with the pathogen); b) developing diagnostic tests and evaluating them; c) developing
therapeutics and testing them; d) developing vaccines and testing them; e) carrying
out formative research and community engagement, ultimately conducting demonstration
projects and forming the use cases; f) and working with industry, as well as advisory,
regulatory and other policy-making bodies to advocate for and develop guidelines for
use.
Benefits of an interdisciplinary approach extend beyond identifying infectious etiologies
of cancers. For example, cancer and HIV research share several challenges in the development
of targeted and effective therapies for eradication/cure or remission. A synergistic
approach will uncover similarities between the two disciplines, and allow for the
use of well-established methodologies, approaches and practices from one area to advance
the other. While effective therapies for cancer may not give the desired results for
HIV cure or remission, or vice versa, a synergistic approach will provide benefit
to both disciplines.
Intentionally focusing on infectious disease and oncology linkages in academic settings
in Africa is no small undertaking. However, the concept aligns with progress in shifting
centers of gravity for where state-of-the-art public health research occurs [15];
sustainable progress is more credible if research to benefit populations in Africa
is derived and led within the continent. Useful outcomes will require a supportive,
collaborative and highly connected environment with sophisticated research investigators,
laboratories and equipment, clinical research capacity, population-based community
research settings and registries, as well as the capacity to translate findings into
products for testing and ultimately clinical and public health use.
The University of the Witwatersrand (Wits) in Johannesburg, South Africa is establishing
an Infectious Diseases and Oncology Research Institute (Wits-IDORI), built on a core
of internationally recognized scientists conducting cutting edge research in cancer
and infectious diseases, ranging from basic sciences to Phase III human clinical trials
within well-established collaborative networks. Wits-IDORI will be a collaborative
venture with scientists from universities across Africa, many already operating according
to international standards, and with academic partners and industry worldwide. IDORI
will engage national public health institutes, the Africa Centres for Disease Control,
the African Regional Office of WHO (AFRO) and a variety of professional organizations
dedicated to access to effective cancer management. Doing this work in Africa, and
promoting the next generation of African scientists will help to ensure that research
outputs reduce the growing burden of cancer on the continent, while strengthening
scientific capacity.
Initially, Wits-IDORI will focus on priority cancers, based on burden data in Africa.
Wits- IDORI will design epidemiologic, clinical, and basic science investigations
to elucidate pathogen-facilitation of cancer development with an eye towards identifying
prevention, diagnostic and therapeutic tools that will lead to measurable beneficial
outcomes at population-levels. The Institute will also focus on research to provide
evidence for minimizing devastating impacts of infectious diseases on cancer, such
as optimizing timely empiric therapy for managing febrile neutropenic pediatric and
adult patients.
Wits-IDORI will emphasize and promote collaboration on high quality, state of the
art investigations with a culture of nurturing and retaining excellent young people
in training, and junior scientists in Africa. Optimal, sustainable success of Wits-IDORI
will depend on strategic investments. Wits-IDORI will build on multi-faceted scientific
partnerships with African institutions, including Universities across the continent,
and globally, to accelerate progress to products and strategies to reduce burden in
Africa and beyond. Defining novel pathways to oncogenesis and cancer burden will pave
pathways for cost-efficient diagnostics, therapies and vaccines. Public health ramifications
of achieving this vision are immense.