The same mRNA technology that brought us COVID-19 vaccines is now revealing surprising potential in the fight against cancer.
When the COVID-19 pandemic swept across the globe in early 2020, it created unprecedented challenges for every facet of healthcare. But perhaps no patient population faced more complex threats than people with cancer—those already navigating life-threatening diagnoses who suddenly found themselves exceptionally vulnerable to a new virus. The oncology community braced for disaster as studies revealed cancer patients faced significantly higher risks of severe COVID-19 outcomes, with one analysis showing they experienced severe events at nearly five times the rate of non-cancer patients 1 .
Yet amidst the crisis, something remarkable happened. The relentless pressure of the pandemic forged unexpected innovations, accelerated long-needed reforms, and revealed surprising connections between viral infections and cancer biology that are now reshaping oncology in ways that will benefit patients for decades to come.
Early in the pandemic, the ominous connection between cancer and COVID-19 severity became quickly apparent. Patients with cancer faced a double threat: their underlying condition and often-compromised immune systems made them more susceptible to severe COVID-19 complications, while the virus itself disrupted the very healthcare systems they depended on for survival 2 .
The statistics were concerning. A pooled analysis of multiple studies found that approximately 2% of all COVID-19 patients had underlying cancer—a proportion significantly higher than in the general population 1 . More alarmingly, among those who became critically ill or died from COVID-19, the percentage with cancer was substantially higher, ranging from 8% in Italian ICU admissions to 20.3% among patients who died from COVID-19 in Italy 3 .
As healthcare systems worldwide scrambled to respond to COVID-19, cancer care experienced severe disruptions. The delay in cancer screenings and diagnoses created what experts fear will be a "stage shift"—with cancers being diagnosed at later, more advanced stages, potentially leading to poorer long-term outcomes 4 .
The numbers tell a stark story. A 2020 report in JAMA Oncology revealed a drastic decline in the diagnosis of six common cancers during the pandemic's first months 4 . Meanwhile, a global survey by the European Society for Medical Oncology found that more than 50% of cancer patients faced treatment delays, with variations depending on region and local COVID-19 burden 4 .
| Aspect of Care | Pre-Pandemic Norm | During Pandemic | Consequence |
|---|---|---|---|
| Cancer screenings | Routine schedule | Significant reductions | Later-stage diagnoses |
| Elective surgeries | Standard scheduling | Postponed or canceled | Disease progression |
| Chemotherapy/radiation | Continuous treatment | Modifications or delays | Potential reduced efficacy |
| In-person consultations | Standard practice | Shifted to telemedicine | Reduced infection risk but communication challenges |
Faced with the impossible choice between continuing essential cancer treatments and risking COVID-19 exposure, the oncology community turned to technology. Telemedicine transitioned from niche offering to cornerstone of cancer care almost overnight, allowing patients to continue receiving consultations, follow-up visits, and even some forms of supportive care while minimizing infection risk 4 .
This transformation proved more than a temporary fix—it revealed a new paradigm for patient-centered care. The convenience of reducing travel for routine visits, particularly for those living far from cancer centers, and the ability to integrate family members into virtual consultations demonstrated benefits that will likely make telemedicine a permanent fixture in oncology 5 .
85% of cancer centers implemented telemedicine during the pandemic, up from less than 10% pre-pandemic.
The pandemic's impact extended to cancer research, with dire consequences. New clinical trials dropped by 60% during the pandemic, and an estimated 99,940 patients were not enrolled in trials that were stopped 5 . The disruption threatened to delay the development of new cancer therapies by years.
Yet these challenges sparked necessary reforms. The oncology community began implementing more flexible trial designs, including remote monitoring, electronic documentation, telehealth visits, and delivery of research-related care at local clinical sites 5 . These changes addressed longstanding structural barriers to trial participation and promised to make future cancer research more efficient and accessible.
Rigid protocols requiring frequent in-person visits
Remote monitoring and decentralized approaches
Hybrid designs combining in-person and remote elements
Perhaps the most thrilling development to emerge from the pandemic is the discovery that COVID-19 mRNA vaccines may enhance cancer treatment. Research presented at the 2025 ESMO Congress revealed that advanced cancer patients who received mRNA COVID-19 vaccines within 100 days of starting immunotherapy lived significantly longer than those who did not get vaccinated 6 7 .
The effect was most dramatic in patients with immunologically "cold" tumors—those not expected to respond well to immunotherapy. These patients experienced a nearly five-fold improvement in three-year overall survival after receiving a COVID-19 vaccine 7 . The researchers found that mRNA vaccines work like an alarm system, putting the body's immune system on high alert and creating a perfect environment for immunotherapy drugs to unleash immune cells against cancer 7 .
While the mRNA vaccine story brings hope, other research revealed a more concerning connection between respiratory viruses and cancer. A landmark study published in Nature showed that respiratory infections like COVID-19 can awaken dormant cancer cells in the lungs, raising the risk of metastatic disease 8 .
"Dormant cancer cells are like the embers left in an abandoned campfire, and respiratory viruses are like a strong wind that reignites the flames," explained Dr. James DeGregori, deputy director of the CU Cancer Center, who led the research 8 .
The study found that infection with either flu virus or SARS-CoV-2 led to a massive expansion—more than 100-fold—of previously dormant breast cancer cells in animal models. Analysis of human data confirmed the concerning trend: cancer survivors who contracted COVID-19 had significantly higher odds of dying from their cancer, particularly in the first year after infection 8 .
| Cancer Type | Unvaccinated Median Survival | Vaccinated Median Survival | Survival Benefit |
|---|---|---|---|
| Advanced Non-Small Cell Lung Cancer | 20.6 months | 37.33 months | Near doubling of survival |
| Metastatic Melanoma | 26.67 months | Not yet reached (30-40+ months) | Significant improvement |
Increase in dormant cancer cells after respiratory infection
Survival improvement in "cold" tumor patients with mRNA vaccines
Drop in new clinical trials during pandemic
Cancer patients facing treatment delays
The groundbreaking research that revealed how respiratory viruses awaken dormant cancer cells employed a multi-faceted approach:
The findings were striking. Both SARS-CoV-2 and influenza infections triggered massive expansion of previously dormant cancer cells in the lungs—increasing their numbers more than 100-fold 8 . Analysis of the UK Biobank data revealed that the chance of dying from cancer was substantially higher among people who had contracted COVID-19, with the risk strongest in the year after infection 8 .
Further analysis of data from Flatiron Health focusing on women with breast cancer showed that contracting COVID-19 significantly increased the risk of developing metastatic disease in the lungs, directly aligning with the experimental results from animal models 8 .
The researchers identified interleukin 6 (IL6), a cytokine known to be involved in inflammatory responses, as a key driver of this reawakening process. This finding was particularly significant because IL6 is already targeted in severe COVID-19 cases with FDA-approved drugs, suggesting a potential dual benefit of these medications 8 .
| Research Aspect | Experimental Findings | Human Data Correlations |
|---|---|---|
| Effect of respiratory infection | 100-fold increase in dormant cancer cells in lungs | Increased cancer mortality after COVID-19 infection |
| Timeframe of risk | Rapid activation after infection | Strongest risk in first year after infection |
| Biological mechanism | IL6-driven inflammatory response | Existing IL6-blocking drugs potentially protective |
| Cancer type studied | Breast cancer models | Confirmed in breast cancer patients, potentially other cancers |
The remarkable discoveries emerging from the intersection of COVID-19 and cancer research rely on specialized tools and methodologies. Here are some key components of the research toolkit that enabled these advances:
| Tool/Reagent | Function | Application Example |
|---|---|---|
| mRNA vaccines | Train immune systems to recognize threats; activate immune responses | Enhancing effectiveness of immunotherapy in cancer patients 6 7 |
| Animal models | Simulate human disease processes; test interventions | Studying effects of viral infections on dormant cancer cells 8 |
| Interleukin-6 (IL6) inhibitors | Block inflammatory signaling | Investigating prevention of dormant cancer cell awakening 8 |
| Lipid nanoparticles | Deliver genetic material (including mRNA) into cells | Component of both COVID-19 vaccines and experimental cancer vaccines 6 |
| Immune checkpoint inhibitors | "Release the brakes" on immune cells | Combined with mRNA vaccines to enhance anti-cancer immunity 6 7 |
| Large health databases | Provide real-world patient data | Analyzing outcomes of cancer patients with COVID-19 8 3 |
The COVID-19 pandemic presented extraordinary challenges for cancer patients, their families, and healthcare providers. Yet it also forged innovations and discoveries that are permanently reshaping oncology. The rapid adoption of telemedicine, reforms to make clinical trials more accessible, and surprising discoveries about the connections between viral immunity and cancer defense all emerged from this difficult period.
Perhaps the most important lesson is the need for resilient healthcare systems that can adapt to crises without compromising care for vulnerable populations like cancer patients. This requires continued investment in telemedicine infrastructure, strategic stockpiling of essential medical supplies, and developing clear guidelines for cancer management during future public health emergencies 4 .
As the world continues to navigate the aftermath of the pandemic, the oncology community has emerged with new tools, new knowledge, and a renewed commitment to transforming cancer care. The challenges were immense, but the successes and lessons learned will benefit cancer patients for decades to come.
The pandemic revealed that even in crisis, there exists opportunity—to innovate, to collaborate, and to advance our understanding of disease in ways that ultimately improve patient outcomes. As research continues to unravel the complex connections between COVID-19 and cancer, one thing remains clear: the resilience of patients, healthcare providers, and researchers has forged a path toward more effective, accessible, and equitable cancer care for the future.