Question explored with the scientific record
can immunotherapy cause cancer to develop faster?
The short version: the evidence does not answer whether immunotherapy can accelerate tumor growth, because the question was never studied head-to-head against a true untreated control.
The evidence you retrieved is almost entirely about who benefits from immunotherapy, not who is harmed by it. The meta-analysis of CD8+ tumor-infiltrating lymphocytes [1] shows that patients with more immune cells in their tumors live longer on checkpoint inhibitors. The CheckMate 032 trial [2] reports a 12% response rate in small cell lung cancer, meaning 88% of patients did not respond. The mismatch-repair study [10] found zero responses in 18 patients with mismatch-repair-proficient colorectal cancer. None of these studies included a control arm that received no treatment at all, so they cannot distinguish between a patient whose tumor grew faster because of the drug and one whose tumor grew at its natural rate.
The hypothesis that immunotherapy could accelerate growth is biologically plausible. The evidence records document dozens of immune-related adverse events—myocarditis with 9-second cardiac arrests [14], bile duct obstruction [15], neutropenia that killed 41% of affected patients [23], acute thrombosis [25]. These are not subtle. If the same immune overactivation that attacks the heart and bone marrow can also stimulate tumor growth in some contexts, the mechanism exists. The CheckMate 026 trial [3] found that patients with low tumor mutational burden who received nivolumab had worse progression-free survival than those who got chemotherapy (hazard ratio 1.82), meaning the drug was actively harmful in that subgroup. That is the closest the evidence comes to answering your question.
My call: the evidence does not rule out acceleration, and the mechanism is plausible, but no study in this retrieval was designed to detect it. Confidence: low, because the question was never asked in a trial that could answer it.
Sources examined 25
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The association between CD8+ tumor-infiltrating lymphocytes and the clinical outcome of cancer immunotherapy: A systematic review and meta-analysis
A comprehensive meta-analysis of 33 studies (2559 patients) showing high CD8+ tumor-infiltrating lymphocytes (TILs) in tumor tissue—across intra-tumor, stroma, or invasive margin—predicts better overall survival, progression-free survival, and objective response rate to cancer i…
DOI: 10.1016/j.eclinm.2021.101134 -
Third-Line Nivolumab Monotherapy in Recurrent SCLC: CheckMate 032
CheckMate 032 pooled analysis shows third- or later-line nivolumab monotherapy yields durable responses and meaningful survival with manageable safety in recurrent small cell lung cancer (SCLC), with an objective response rate of 11.9%, median duration of response 17.9 months, 6…
DOI: 10.1016/j.jtho.2018.10.003 -
Impact of high tumor mutational burden in solid tumors and challenges for biomarker application
Tumor mutational burden (TMB) is a prognostic and predictive biomarker for immunotherapy across solid tumors, but standardization of measurement and thresholds remains challenging; plasma TMB offers a non-invasive alternative; harmonization efforts are underway.
DOI: 10.1016/j.ctrv.2020.102084 -
HMGB1 assists the predictive value of tumor PD-L1 expression for the efficacy of anti-PD-1/PD-L1 antibody in NSCLC
This study investigates the potential of serum HMGB1 levels as a predictive biomarker for the efficacy of anti-PD-1/PD-L1 antibody therapy in patients with non-small cell lung cancer (NSCLC), finding that higher HMGB1 levels correlate with improved treatment response and progres…
DOI: 10.1007/s00280-025-04751-2 -
Outcomes of patients with non‐melanoma solid tumours receiving self‐funded pembrolizumab at Chris O'Brien Lifehouse
This retrospective study evaluates the outcomes and toxicity of self-funded pembrolizumab in patients with non-melanoma solid tumors at Chris O'Brien Lifehouse, revealing a low response rate and significant financial burden on patients.
DOI: 10.1111/imj.13232 -
Comprehensive molecular characterization of clinical responses to PD-1 inhibition in metastatic gastric cancer
This study investigates the molecular characteristics and clinical responses to PD-1 inhibition in metastatic gastric cancer, revealing that patients with microsatellite instability-high (MSI-H) and Epstein-Barr virus-positive tumors exhibit significantly higher response rates t…
DOI: 10.1038/s41591-018-0101-z -
A multicentre and randomised prospective study comparing three intravesical therapies, two with Bacillus Calmette-Guerin inmunotherapy and one with mitomicyn-C chemotherapy in medium and low risk superficial bladder tumours
This study compares the long-term efficacy and toxicity of two intravesical therapies, Bacillus Calmette-Guerin (BCG) immunotherapy and mitomycin C (MMC) chemotherapy, in patients with medium and low-risk superficial bladder tumors, finding that BCG significantly reduces recurre…
DOI: 10.1016/s1569-9056(02)80388-8 -
Advances in Cancer Immunotherapy: Enhancing the Immune Response and Addressing Therapeutic Challenges
A comprehensive overview of cancer immunotherapy modalities, including cell-based therapies, vaccines, cytokines, oncolytic viruses, and immune checkpoint inhibitors, highlighting clinical progress and ongoing challenges.
DOI: 10.61173/vzsn1s98 -
CD200R, a co-inhibitory receptor on immune cells, predicts the prognosis of human hepatocellular carcinoma
This study investigates the prognostic significance of CD200R expression in hepatocellular carcinoma (HCC), revealing that higher levels of CD200R are associated with increased tumor size, poor survival rates, and may serve as a potential therapeutic target.
DOI: 10.1016/j.imlet.2016.08.009 -
PD-1 Blockade in Tumors with Mismatch-Repair Deficiency
A phase-2 trial of pembrolizumab across three cohorts showed that tumors with mismatch-repair deficiency (MMR-d)—including colorectal and noncolorectal cancers—have high response rates and prolonged progression-free survival compared with mismatch-repair-proficient (MMR-p) color…
DOI: 10.1056/nejmoa1500596 -
Adjuvant Topical Chemotherapy versus Immunotherapy in Primary Superficial Transitional Cell Carcinoma of the Bladder
This study compares the efficacy of ethoglucid and keyhole-limpet haemocyanin (KLH) in preventing recurrent tumors in patients with primary superficial transitional cell carcinoma of the bladder, finding no statistically significant differences in recurrence rates or disease-fre…
DOI: 10.1111/j.1464-410x.1991.tb15072.x -
SARS-CoV-2 mRNA Vaccines as Immunologic Adjuvants to Overcome Tumour Resistance to Immune Checkpoint Blockade
Peri-immunotherapy SARS-CoV-2 mRNA vaccines prime innate immunity and reprogram the tumor-immune interface to enhance checkpoint blockade responses across cancers, most notably in PD-L1–low NSCLC, though causal proof awaits prospective testing.
DOI: 10.33140/jtma.05.01.07 -
Patterns, risk factors and management of CD19-directed chimeric antigen receptor T-cell therapy failure in CNS lymphoma
Baseline peripheral contrast enhancement and leptomeningeal disease independently predict shorter CNS-progression-free survival after CD19-CAR therapy in CNS lymphoma, and salvage immune checkpoint inhibitors or lenalidomide-based regimens can yield durable responses after CAR-T…
DOI: 10.1186/s13045-025-01761-8 -
Immune-related myocarditis characterized by malignant arrhythmia caused by conduction system involvement: case report and literature review
Two patients developed immune checkpoint inhibitor-related myocarditis with conduction system involvement and malignant arrhythmia, treated with conventional-dose corticosteroids and pacemaker support, with good clinical outcomes.
DOI: 10.3389/fonc.2025.1589990 -
Bile duct obstruction in a patient treated with nivolumab as second-line chemotherapy for advanced non-small-cell lung cancer: a case report
This case report describes a 63-year-old Japanese man with advanced lung adenocarcinoma who developed bile duct obstruction as an immune-related adverse effect of nivolumab treatment, which was successfully managed with high-dose prednisone and stenting.
DOI: 10.1007/s00262-017-2062-3 -
Outcomes Following Immunotherapy Re-Challenge After Immune-Related Adverse Event: Systematic Review and Meta-Analysis
This systematic review and meta-analysis evaluates the safety and efficacy of re-challenging patients with immune checkpoint inhibitors after experiencing immune-related adverse events, finding that re-challenge is associated with lower rates of severe adverse events and a modes…
DOI: 10.2217/imt-2020-0103 -
Effects of immune related adverse events and corticosteroids on the outcome of patients treated with immune checkpoint inhibitors
This study investigates the impact of immune-related adverse events (irAEs) and corticosteroid use on treatment outcomes in patients with advanced non-small cell lung cancer (NSCLC) receiving immune checkpoint inhibitors, finding that irAEs are associated with improved overall s…
DOI: 10.1038/s41598-025-91102-z -
Hypertrophic lichenoid dermatitis immune‐related adverse event during combined immune checkpoint and exportin inhibitor therapy: A diagnostic pitfall for superficially invasive squamous cell carcinoma
A case report describing hypertrophic lichenoid dermatitis as an immune-related adverse event during combined pembrolizumab (anti-PD-1) therapy and an exportin-1 inhibitor in a patient with metastatic melanoma, including clinical, dermoscopic, and histopathologic features that m…
DOI: 10.1111/cup.13739 -
Association of Cutaneous Immune-related Adverse Events with Overall Survival and Progression-free Survival in Oncology Patients Receiving Immune Checkpoint Inhibitors: A Prospective Study of 189 Patients in a Spanish Tertiary Care Hospital
This prospective observational study investigates the association between cutaneous immune-related adverse events (cirAEs) and overall survival and progression-free survival in 189 oncology patients receiving immune checkpoint inhibitors at a Spanish tertiary care hospital, find…
DOI: 10.2340/actadv.v105.42023 -
Association Between Immune-related Adverse Events and Efficacy of Immune Checkpoint Inhibitors in Non–small-cell Lung Cancer
This study investigates the association between immune-related adverse events (IRAEs) and the efficacy of immune checkpoint inhibitors (ICIs) in 270 patients with advanced non-small cell lung cancer (NSCLC), finding that patients experiencing IRAEs had significantly better overa…
DOI: 10.1016/j.cllc.2018.10.002 -
Adverse events associated with immune checkpoint inhibitors in patients with breast cancer: A systematic review and meta-analysis
A comprehensive systematic review and meta-analysis assessing the frequency and severity of adverse events and immune-related adverse events in adults with breast cancer treated with immune checkpoint inhibitors versus conventional therapies, demonstrating higher incidences of A…
DOI: 10.1016/j.intimp.2021.107796 -
Clinical outcomes of endocrine and other disorders induced by immune checkpoint inhibitors in Japanese patients
This study investigates the clinical outcomes and survival rates of Japanese patients treated with immune checkpoint inhibitors (ICIs) and the associated endocrine-related and other immune-related adverse events (irAEs), revealing that patients with irAEs, particularly those inv…
DOI: 10.1038/s41598-024-84488-9 -
Challenges in diagnosis and management of neutropenia upon exposure to immune-checkpoint inhibitors: meta-analysis of a rare immune-related adverse side effect
This study presents a two-case report and a systematic review with meta-analysis of 34 cases of neutropenia as a rare immune-related adverse event during immune checkpoint inhibitor therapy, detailing onset, clinical course, treatments (G-CSF, corticosteroids, IVIG), infection r…
DOI: 10.1186/s12885-020-06763-y -
Correlations Between the Immune-related Adverse Events Spectrum and Efficacy of Anti-PD1 Immunotherapy in NSCLC Patients
This study investigates the predictive and prognostic roles of immune-related adverse events (irAEs) in patients with non-small-cell lung cancer (NSCLC) treated with anti-PD-1 immunotherapy, finding that the occurrence of irAEs is associated with improved overall response rates,…
DOI: 10.1016/j.cllc.2019.02.006 -
Pembrolizumab-induced acute thrombosis
This case report presents two patients with non-small cell lung cancer who developed acute thrombosis as an immune-related adverse event following pembrolizumab treatment, highlighting the need for awareness and management of such rare but serious complications.
DOI: 10.1097/MD.0000000000010772