The problem of cancer has long been supported by public taxation, private philanthropy and business investment (1), with this support having been both a cause and effect of clinical and scientific breakthroughs – including but not limited to adjuvant therapies, targeted therapies, immunotherapies, digitised imaging technologies, genetic sequencing, and cancer-preventive vaccines. Indeed, the term “oncology” only entered professional usage after proclamation of a War on Cancer by President Nixon in the lead-up to his 1972 re-election (2); this anti-cancer campaign was revived in 2016 by the Cancer Moonshot project, “re-ignition” of which was declared in 2022 by President Biden, with the goal of reducing age-specific cancer deaths by 50% over 25 years (3).

To understand the success [notwithstanding certain caveats (4)] of what has so far been a half-century campaign, it should first be asked why cancer has attracted more funding per unit of disease-specific mortality than have most other health issues; for example, there has been no similar support for a War on Heart Disease, even though cardiovascular problems have long caused higher death rates and health costs than cancer (5). This depth of support for cancer has been attributed to perceptions that a cancer diagnosis presents a unique existential threat [i.e., an “unspeakable” illness (6)] that not only poses lethal risks but also creates spiritually arduous – whether “moralistic” or “militaristic” – uncertainties as to the timing of cancer recurrence, nature of future symptoms, disease response or resistance, and speed (rapidity or slowness) of death (7).

Nonetheless, since resources are limited in any system, even the most serious personal health concerns (8, 9) must ultimately compete for support with societal-level threats (10, 11). During the first two decades (1971-90) of the War on Cancer, such threats included overpopulation, risks of nuclear war, and the HIV pandemic. Concerns over these issues abated over time; in hindsight, this fading of competing threats – akin to a peace dividend (12) – enabled sharper focus on the individual risk of a cancer diagnosis. Looking ahead, although cancer will always loom large as a major worry for personal health (13), the association of this disease with aging [i.e., with a low detriment to species fertility (14)] ensures that its impact on humanity will remain modest (15).

Competing threats to the traditional support base for cancer lie ahead. Amongst these are the approaching impacts of global population aging, in tandem with falling birth rates (16), on oncology practice. Population aging will increase the aggregate burden of cancer diagnoses (17), even as age-specific cancer prevalence declines due to preventive advances; hence, as populations age over the coming decades, cancer will become commoner, but mainly among adults older than 65 years who will tend to have more age-related frailties than those diagnosed (younger) in the past (18). On the positive side, this greater longevity partly reflects improved disease prevention and wellness (19) (“healthy aging”, “delayed aging”), just as falling fertility may arise to some extent from more effective contraception (20).

Whatever the reasons for population aging, a key consequence for today’s oncologists is that their future (older) patients – who despite healthy aging are likely to have on average more restricted activities of daily living, more tenuous quality of life, and more competing causes of death (18) – may come to value autonomy and life quality relatively more highly than did their survival-focused predecessors (21, 22). The advent of patient-reported outcome measures represents a major step forward in this process of change, signaling as it does a ‘personalisation’ not of treatment targeting but of quality-of-life feedback and optimisation. Although such changes will not transform practice in the present decade, by 2040 evidence of this transition is predicted to become clear (23).

A different threat to human livelihoods is environmental degradation (24). There may seem little that links oncology practice and the causes or effects of environmental decline; yet when all correlates of the latter problem are considered – global warming, weather disasters, species displacements driving risks of disease spread to humans, travel restrictions, decarbonisation costs, energy shortages, rising prices, geopolitical instability – a total disconnect seems unlikely (25). At the least, traditional access to funding and philanthropy is likely to be constrained by competing cost-intensive problems like climate change (26), with the result – amplified by population aging – that resources for cancer become squeezed. Hence, although paradigm-shifting therapeutic advances must continue to add benefit for cancer patients in the future, other emerging challenges are likely to diminish investment in cancer therapeutics over time, especially when expressed as a fraction of world expenditures against all threats.

Public acceptance of this new reality could bring with it a slow change from an individualistic view of health as priceless (27) to a more socially cognizant “doughnut economics” (28), with proposals of this kind having already been made (29). Such a trend is also consistent with the Moonshot initiative which, in contrast to the War on Cancer, is not driven by major new funds; instead, the Moonshot proposes a switch of emphasis limited to an additional 5% of existing funding, with prevention as the priority. A transition of this kind aligns with recommendations to invest in a Culture of Health (30), based on a mindset valuing shared community needs (31, 32) at least as highly as the ‘magic bullet’ hope and hype which has for so long energised cancer research (33).

Different cultures of oncology already exist in different parts of the world, implying that changes are possible in any knowledge system (34). For cancer care to evolve from its golden age values to a more equable and lower-profile green age culture ( Table 1 ), resistance may be eased by educational campaigns which can convince both public and professionals that these selection pressures reflect essential adaptive challenges for modern healthcare (35). A stepwise approach to this cultural transition is suggested below.

The choice of a War on Cancer as an encore to the Apollo moon landings signalled the zenith for cancer as an existential human threat, kicking off a golden age for the science and practice of oncology. Times have since changed, however, as population aging and planetary threats have altered the trajectory of public concerns. The field of oncology is likely to feel these pressures to adapt within the next two decades, and the healthcare changes that result over the next fifty years could prove to be just as important and beneficial as the paradigm shifts that preceded these.

A global approach, based on public and professional education (65), will be needed to bring about economics-based system changes that can adapt to the disruptive evolutionary era ahead (66). Crosstalk with all stakeholders – including, though not limited to, patients, physicians, advocacy groups, governments, insurers, and pharmas – will necessarily precede such changes. The 20^th century paradigm of ever more resources (ultimately derived from the environment) being harnessed to deliver ever more personalised oncologic increments (ultimately benefiting individuals more than populations) may prove to be less sustainably applicable to the 21^st century world, where an imbalance between human demand and ecosystem fragility has become evident. Constructive change will require that concepts such as ‘greater good’, ‘big picture’ and ‘longer term’ come to be pursued more systematically than the self-interested priorities of the past.

RE wrote the first draft with inputs from FL and YG, then the second draft was further appraised and critiqued by FL and YG. All authors contributed to the article and approved the submitted version.