Neoplasia and Autoimmune Disease Save

Malignancy rivals cardiovascular disease as a leading cause of death in patients with systemic autoimmune diseases. Chronic inflammation and immune dysregulation can drive oncogenesis, while antitumor immune responses can trigger autoimmune phenomena (paraneoplastic syndromes, checkpoint inhibitor-induced rheumatic disease).

Key Takeaways

• Malignancy as a leading cause of death in autoimmune disease, with the bidirectional cancer–autoimmunity relationship
• Increased inflammatory disease activity is consistently related to greater cancer risk
• Cancer screening should follow general population guidelines, but intensified with high-risk features (RNA polymerase III antibodies in systemic sclerosis, or anti-TIF-1γ and NXP-2 antibodies in dermatomyositis)
• Disease-specific guidance for cancer screening exists for IIM, Sjögren's, SSc, SLE, and VEXAS
  • Inflammatory myopathies carry the highest absolute cancer risk (mostly solid tumors; ~25% within 5 years); heightened in the presence of anti-TIF1-γ and anti-NXP2 antibodies. Consider annual cancer screening for at least 3 years post-diagnosis.
  • Sjögren's disease confers the highest relative lymphoma risk of any autoimmune condition (SIR up to 19x). Worry about parotid enlargement, cryoglobulins, C4 hypocomplementemia, monoclonal gammopathy, and high ESSDAI scores.
  • Anti-RNA polymerase III antibody in systemic sclerosis is strongly associated with synchronous cancer — particularly breast cancer.
• Hydroxychloroquine has a dose-dependent protective effect against malignancy in SLE and should be continued unless contraindicated.
• Cyclophosphamide carries meaningful bladder and myeloid cancer risk — use the minimum effective cumulative dose and surveil appropriately post-exposure.
• VEXAS syndrome is linked to myeloid malignancy and clonal hematopoiesis. Mandatory hematology co-management and MDS surveillance are essential from diagnosis.

Malignancy rivals cardiovascular disease as a leading cause of death in patients with systemic autoimmune diseases. Chronic inflammation and immune dysregulation can drive oncogenesis, while antitumor immune responses can trigger autoimmune phenomena (paraneoplastic syndromes, checkpoint inhibitor-induced rheumatic disease).

While there is often concern about cancer risk with immunosuppressive therapies, for most, the risk is driven by disease, more so than therapies (with few exceptions). Conventional DMARDs (csDMARDs) have not been consistently associated with a significant increase in cancer risk. Methotrexate may increase the risk of a new nonmelanomatus skin cancer (NMSC) in patients with previous skin cancer, and mycophenolate mofetil has been associated with an increase in skin cancer, and possibly lymphoma, but primarily in patients with solid organ transplantation. Nonetheless, the rheumatologist must be vigilant in considering the risk of cancer longitudinally.

Potential mechanisms linking chronic autoimmunity to malignancy:

• Chronic inflammation and DNA damage: Sustained production of reactive oxygen species, cytokines (TNF, IL-6, IL-17), and NF-κB activation damages DNA, impairs tumor suppressor function, and creates a microenvironment permissive to neoplastic transformation. This is the dominant mechanism in conditions like RA and scleroderma-associated lung cancer.
• Pathological B–T cell collaboration: A 2026 Nature Communications study identified a specific mechanism — chronic idiotype-driven T–B cell co-stimulation — in which autoreactive B cells receive continuous dual activation signals from Id-specific T cells. Over time, this chronic, poorly regulated B–T collaboration drives clonal B-cell expansion and progression to lymphoma. This mechanism may explain the dramatically elevated lymphoma risk across many autoimmune diseases, and represents a potential therapeutic intervention target.
• Immunosuppression-related impaired tumor surveillance: Chronic use of immunosuppressive agents — particularly cyclophosphamide, azathioprine, and high-dose glucocorticoids — impairs cytotoxic T-cell and NK-cell tumor surveillance, allowing transformed cells to escape immune clearance,

Drug Therapy and Cancer Risk

• TNF inhibitors in RA do not increase overall cancer risk or lymphoma risk beyond that of RA itself.
• Rituximab, by depleting B cells, may reduce lymphomagenesis risk in Sjögren's disease, although robust RCT data are lacking.
• Oral Surveillance trial in older RA patients with cardiovascular risk factors showed a higher risk of certain cancers (lung, skin) with tofacitinib; OR conversely showed that adalimumab (TNF inhibitor) had lower risk of these cancers. Nevertheless, JAK inhibitors carry the FDA black box warning for lymphoma and other malignancies.
• Skin cancer will affect 20% of the population.  Skin cancers (NMSC and melanoma) appear to be higher in patients with autoimmune inflammatory rheumatic diseases (AIRD), hence screening skin exams with periodic annual screens are indicated for many rheumatologic patients.
• Past ACR guidelines have recommended that AIRD patients with solid tumors should be treated the same as if they did not have cancer. Meaning, there is no credible evidence that aggressive or biologic therapies will affect their cancer outcomes.

Disease Specific Cancer Screening

There are no universal, disease-specific cancer screening guidelines exist for most autoimmune conditions. But there are suggestions and guidances (without substantial evidence) to support disease specific screenings:

• Idiopathic Inflammatory myopathies (IIM): most should have age appropriate health maintenance and cancer screens. But for those deemed to be high risk (eg, with Anti-TIF1-γ and anti-NXP2 antibodies) comprehensive screening at diagnosis (CT chest/abdomen/pelvis, age-appropriate colonoscopy, mammography, PSA, CA-125 may be indicated and repeated for the first 3 years after diagnosis.
• Sjögren's disease: Lymphoma monitoring should be considered in patient with parotid enlargement, cryoglobulinemia, C4 consumption, monoclonal gammopathy, lymphadenopathy, and possibly with high ESSDAI scores. Many suggest a low threshold for lymph node biopsy is appropriate.
• Systemic sclerosis: patients with anti-RNA polymerase III antibody should be screened for synchronous breast cancer at diagnosis. Also consider annual CT scans for lung cancer in patients with established ILD.
• SLE: Annual cervical cytology for all women, especially those on cyclophosphamide or other immunosuppressants. Post-cyclophosphamide patients: consider periodic urinalysis/urine cytology for bladder cancer surveillance.
• VEXAS syndrome: Hematology co-management is mandatory; MDS and plasma cell dyscrasias may precede, coincide with, or follow VEXAS diagnosis.

Disease-Specific Cancer Risk