Cancer Rates & COVID-19: What the Data Actually Shows

Cancer screenings dropped 86–94% in early 2020. Delayed diagnoses are now presenting as apparent new cases. This is the strongest and most evidence-supported explanation for the apparent cancer surge.

Biologically plausible, increasingly studied at the cellular level, not yet proven at the population level. Mechanisms identified include tumor suppressor gene inhibition, immune dysregulation, and MAPK/NF-κB pathway activation.

Signals exist in some observational studies. Confounding is significant. Causation is not established. It is not disproven either. Prospective data is urgently needed.

Pre-Existing Trend

International incidence: 0.59–5 per 100,000 persons annually, rising before COVID. Approximately 13,000 new GBM diagnoses in the U.S. annually. Median age at diagnosis 64 years. 15-month median survival despite advances in surgery, radiotherapy, and chemotherapy.

COVID as Risk Factor

Mendelian randomization study (Frontiers in Oncology, 2023): 6,183 GBM cases and 18,169 controls. Genetically predicted COVID-19 hospitalization increases GBM risk (OR=1.202, 95% CI=1.035–1.395, p=0.016). First study to identify COVID-19 hospitalization as a documented risk factor for GBM development.

COVID Accelerates Existing GBM

MD Anderson Cancer Center retrospective study: accelerated tumor progression in GBM patients who contracted COVID-19. SARS-CoV-2 may bind to overexpressed receptors on glioblastoma cells, potentially activating oncogenic pathways including MAPK signaling cascades.

Diagnostic Disruption

Belgian population study (2020): fewer patients with glioblastoma underwent surgery during the pandemic. The proportion of patients receiving no surgery, radiotherapy, or systemic therapy increased by six percentage points. This profoundly impacted diagnosis rates, treatment strategies, and survival.

New 2024–2025 Development

Nature Communications (2024): real-world study of personalized peptide vaccines for GBM — patients with multiple vaccine-induced T-cell responses showed significantly prolonged survival (53 months vs 27 months, p=0.03). mRNA vaccine technology is now being developed as a treatment for GBM — an important counterpoint to the vaccine-risk narrative.

Pre-Existing Rise

Age-adjusted incidence per 100,000: 4.90 in 2000 rising to 8.19 in 2018 (Annual Percentage Change 3.40%, 95% CI 3.13–3.67). The most significant increases were in Grade 1, localized stage, and appendix NETs.

Younger Adults

Nationwide population-based time-trend analysis (DDW 2023, ACG 2023): the incidence of rectal NETs is increasing in younger adults in the U.S. between 2001–2020. This trend predates COVID but may be accelerating.

COVID Care Disruption

International NET CONNECT survey: NET patients require highly specialized and interdisciplinary infrastructure for diagnostics and therapy. Medical care was severely disrupted during the COVID-19 pandemic for this population specifically.

Case Report — Vaccine and Pituitary NET

Nara Medical University (Frontiers in Surgery, 2023): a 45-year-old male developed pituitary apoplexy causing acute visual loss three days after his second COVID-19 vaccination. A pre-existing but undiagnosed pituitary NET was likely precipitated by vaccination-induced inflammation. Single case — not generalizable, but raises legitimate questions.

SCLC — The Counterintuitive Signal

Overall SCLC incidence is declining due to reduced smoking. However: SCLC in never-smokers is rising — a distinct and unexplained signal that warrants monitoring.

Breast Cancer

Screening dropped 94% in early 2020 — catch-up diagnoses are still presenting through 2024. ACS Annual Report 2025: among women, rates of new stomach cancer cases increased fastest (3.2%/year) while lung cancer fell fastest. No clear vaccine signal after controlling for screening access differences.

Colorectal Cancer

Rising in young adults — this trend began well before COVID. Post-pandemic: screening gaps plus diagnostic disruption are compounding an already alarming trajectory. Brazilian case series (2022): 3 previously healthy young adults diagnosed with hematologic malignancies 2–3 months post-COVID infection (T-cell ALL, MDS, AML). No causal determination is possible from a case series.

Prostate Cancer

ACS Annual Report 2025: the steepest increasing trend among men — AAPC 2.9% all races combined, ranging from 1.3% in Hispanic males to 4.0% in API males. PSA testing was severely disrupted during COVID, creating a significant diagnostic backlog now presenting.

Lymphoma

Brazilian case series (2022): a 35-year-old male diagnosed with T-cell acute lymphoblastic leukemia approximately 2 months post-COVID; a 36-year-old male diagnosed with myelodysplastic syndrome; a 31-year-old female diagnosed with AML approximately 3 months post-COVID. Case series only — not generalizable, hypothesis-generating.

Melanoma

Screening delays during COVID caused stage migration — more late-stage presentations at diagnosis across multiple registry reports. No clear overall incidence increase signal was detected in delay-adjusted data.

Mechanism 1 — Immune Suppression

SARS-CoV-2 induces the release of immunosuppressive cytokines IL-10 and TGF-β. These inhibit effective anti-tumor immune responses and promote a tumorigenic microenvironment. Chronic inflammation creates conditions conducive to viral persistence and potentially to oncogenesis.

Mechanism 2 — Tumor Suppressor Inhibition

Unlike classical oncogenic viruses, which transform cells through viral oncogenes, SARS-CoV-2 appears to promote tumorigenesis by inhibiting tumor suppressor genes and pathways while activating survival, proliferation, and inflammation-associated signaling cascades including MAPK and NF-κB.

Mechanism 3 — Apoptosis Interference

The SARS-CoV-2 N protein may inhibit cell apoptosis by affecting the anti-apoptotic protein MCL-1 and Casp-3 cleavage — potentially representing one mechanism by which COVID-19 infection could promote the survival of pre-malignant cells.

Mechanism 4 — Direct GBM Receptor Binding

SARS-CoV-2 has been shown to bind to receptors overexpressed on glioblastoma cells, potentially activating oncogenic signaling pathways directly in tumor cells — distinct from the immune-mediated mechanisms above.

Kim et al. (Biomarker Research, September 2025, peer-reviewed): South Korean National Health Insurance cohort — 8,407,849 individuals followed 2021–2023. The vaccinated group showed a 27% higher overall cancer risk within one year, with signals in lung, prostate, thyroid, gastric, colorectal, and breast cancers.

Italian Pescara province cohort (296,015 residents, 30-month follow-up): a 23% higher cancer hospitalization rate in vaccinated vs unvaccinated individuals.

Case reports of rapid cancer progression temporally associated with vaccination are increasing in the peer-reviewed literature.

• South Korean study: the unvaccinated group comprised only 680,000 of 8.4 million participants — just 8% of the study population. This group had significantly less healthcare access.
• Surveillance bias: vaccinated individuals had more medical contact = more screening = more diagnoses.
• One-year follow-up is too short for most solid tumors to develop from scratch.
• Science Feedback reviewed the study and noted "concerns have been raised with the Editors."
• Official NCI SEER data: 2021 cancer rates were 0.5% below pre-pandemic 2019 levels after delay adjustment.
• Cancer screening dropped 86–94% in 2020 — catch-up diagnoses from delayed screening explain a significant portion of the 2021–2023 apparent surge.
• ACS data: cancer mortality declined 33% from 1991–2021, a period that includes the vaccine rollout.
• Japanese study claiming increased cancer mortality after the third mRNA dose: published in Cureus (2024), subsequently retracted due to methodological flaws.Retracted

Counterpoint — New 2024–2025 Data

VA study (PMC12377599, 2024–2025): lower cancer incidence was observed 3 years post-COVID in vaccinated populations compared to unvaccinated — the opposite of the South Korean signal. Conflicting data must be presented equally.

What We Do Not Know

Whether the South Korean and Italian signals persist after rigorous, equal-screening-access controlled analysis. Whether mRNA technology could influence immune surveillance of pre-existing subclinical malignancies in specific populations. Long-term data beyond 3 years post-vaccination does not exist for most cancer types.

• Pandemic screening disruption explains a significant portion of the apparent cancer surge.
• COVID-19 hospitalization is a documented risk factor for GBM (Mendelian randomization, p=0.016).
• SARS-CoV-2 has documented oncogenic mechanisms at the cellular/molecular level.
• Early-onset cancer rise predates COVID by decades — the pandemic likely accelerated an existing trend.
• Cancer mortality rates continued declining through the pandemic and vaccine rollout period.

• SARS-CoV-2 as a direct population-level oncogenic agent.
• mRNA vaccine contribution to immune dysregulation promoting cancer in susceptible individuals.
• COVID-related immune suppression accelerating subclinical pre-malignant disease.

• Vaccines as the primary cause of the cancer surge.
• "Turbo cancer" as a specific vaccine-induced clinical entity with a defined mechanism.
• Single-cause explanations for what is clearly a multi-factorial trend.
• The retracted Japanese study claiming a mortality increase after the third dose.