Cancer incidence rates did not rise overall following the COVID-19 pandemic or the rollout of COVID-19 vaccines, based on population-level data from health registries and surveillance systems. Instead, diagnoses sharply declined in 2020 due to healthcare disruptions, with partial recovery in subsequent years but without a compensatory surge to account for missed cases. 38 40 44 This led to concerns about delayed detections and potential stage migration (e.g., more advanced presentations), but no evidence of a broad increase in new cancers attributable to the virus itself or vaccines. 41 Claims of “turbo cancer”—aggressive, rapid-onset malignancies supposedly triggered by vaccines—lack scientific support and have been dismissed as misinformation by experts and organizations like the Global Vaccine Data Network. 0 2 3 6 31

Impact of the COVID-19 Pandemic on Cancer Incidence

• Decline in Diagnoses (2020): Globally and in regions like Canada, the U.S., and Europe, new cancer diagnoses fell by 5-46% in early 2020 compared to pre-pandemic averages, primarily due to suspended screenings, delayed elective procedures, and reduced healthcare access during lockdowns. 37 39 42 43 45 For example, in Manitoba, Canada, overall incidence dropped by 23% in April 2020, with steeper falls for breast (46%), colorectal (35-47%), and melanoma (65%) cancers. 44 Lung cancer remained lower throughout 2020. 37
• Recovery and Trends (2021-2022): By 2021, rates approached pre-pandemic levels for most sites, but without a rebound to offset 2020’s deficit—e.g., an estimated 5.3% shortfall in Manitoba (692 fewer cases than expected), largest for breast (14.1%), colon (12.2%), and lung (7.6%). 38 40 44 Some sex-based differences emerged, like sustained colon cancer declines in females but stabilization in males. 39 42 Modeling suggests potential stage shifts (e.g., more stage III/IV breast and lung cancers) due to delays, but no overall incidence spike. 41
• Post-2022 Data: U.S. national surveillance through 2022 shows no abrupt population-wide increase; mortality continued declining, with patterns tied to pandemic disruptions rather than the virus causing more cancers. 14 A 2025 Italian study reported a 2020-2021 rise in incidence (from 14.3 to 23.1 per 1,000 person-years), but this reflects diagnostic recovery, not new cases. 36 COVID-19 infection itself may hypothetically promote oncogenesis via inflammation or immune dysregulation, but real-world evidence is limited to case reports and requires more study. 26 28 34

COVID-19 Vaccines and Cancer Risk

• No Proven Causal Increase: Extensive monitoring, including from the CDC, NCI, and global pharmacovigilance, shows no evidence that COVID-19 vaccines cause or accelerate cancer. 3 6 8 31 Cancers develop over years, so short-term post-vaccination observations (e.g., 1 year) are unlikely to reflect causation. 0 27 VAERS reports of cancers post-vaccination are elevated (18-33x vs. other vaccines), but these are unverified, voluntary, and influenced by reporting bias—not proof of causality. 46 53
• Conflicting Studies: A 2025 South Korean study of ~8.4 million people found associations between vaccination and higher 1-year risks for thyroid (35%), gastric (34%), colorectal (28%), lung (53%), breast (20%), and prostate (69%) cancers, varying by vaccine type (mRNA, cDNA, heterologous). 4 26 However, critics note flaws like surveillance bias (vaccinated people get more checkups), unadjusted confounders (e.g., older/healthier vaccinated cohorts), and short follow-up; the journal added a concerns notice. 0 27 31 An Italian cohort (~300,000) showed slightly higher cancer hospitalization risk post-vaccination (HR 1.23), but this reversed with longer lag times (e.g., lower risk after 1 year), suggesting bias. 28 34 A U.S. military study (~1.3 million) found no broad increase. 28
• Potential Benefits: Emerging research indicates mRNA vaccines may enhance immunotherapy for existing cancers (e.g., nearly doubling survival in advanced lung/melanoma patients vaccinated within 100 days of treatment, from 20.6 to 37.3 months). 29 30 35 9 They appear to boost type I interferon and immune surveillance, potentially sensitizing tumors to checkpoint inhibitors. 30
• “Turbo Cancer” Claims: These originated from anti-vaccine narratives and rely on anecdotes, case reports (e.g., rare lymphomas/sarcomas post-vaccination), or misinterpretations. 1 2 5 7 28 32 10 22 49 A 2026 review of 69 publications (333 cases) noted temporal associations with rapid progression or unusual features, but emphasized these are preliminary, biased toward reporting novelties, and not causal. 28 No biological mechanism (e.g., SV40 DNA fragments) supports vaccine-induced cancer, and long-term data contradict an epidemic. 6 31 Social media amplifies these, often linking to royal family cases or unsubstantiated 1000% rises, but registries show no such trends. 1 12 14 17 20 23 24 25 47 50 51 52 53

Ongoing research is needed to monitor long-term effects, but current evidence prioritizes pandemic disruptions over viral or vaccine causation for observed patterns.