Background: Immunotherapy in cancer is a therapeutic strategy based on stimulating the immune system to recognize and destroy tumor cells. Among immunotherapy, therapies targeting molecular processes occurring in tumor cells stand out. Although these therapies have been a significant advance in the fight against cancer, they can also trigger various immune-mediated adverse effects, some of rheumatological nature.

Objectives: To describe the rheumatological manifestations in cancer patients receiving targeted therapies.

Methods: Multicenter, retrospective, and descriptive study, including patients derivated from oncology related to immunotherapy treatment between January 2020 and December 2023. Demographic and clinical variables were collected. An immune-mediated effect was considered severe if it endangered the patient’s life and/or led to hospitalization, disability, or death. Statistical analysis was performed using R4.3.2.

Results: 56 patients were included. The majority were men (60.7%), with an average age of 65.56 ± 12.56 years. The most frequent comorbidities were hypertension (47.4%), dyslipidemia (44.7%), and type 2 diabetes (28.9%). The immunotherapy treatments received were PD-1 inhibitors: Pembrolizumab (48.2%) and Nivolumab (41.1%) and PDL-1 inhibitors: Atezolizumab (7.1%) and Durvalumab (3.6%). The most common types of neoplasia were lung (51.8%), followed by melanoma (16.1%), renal (10.7%), and digestive tract (7.14%). Other less frequent tumor types included bladder (3.6%), ear-nose-throat area (3.6%), hematological (3.6%), mesothelioma (1.79%), and cervix and lung (1.79%). The most common reasons for referral were arthralgias (77.8%), arthritis (55.6%), and suspected autoimmune disease (37%). After follow-up, the most common diagnosis was “inflammatory arthralgia/polyarthritis” in 51.2% of patients. Other newly diagnosed pathologies were: Sjögren (n=4), RA (n=4), PsA (n=2), lupus-like (n=2), PMR (n=1), myositis (n=1), antisynthetase syndrome (n=1), gout (n=1), scleroderma (n=1), and Behçet’s (n=1). There were 3 patients with a previous diagnosis of Rheumatoid Arthritis and 2 with Systemic Lupus Erythematosus who had a flare, one of them severe, after the start of immunotherapy. In 96.2% of cases, the diagnoses were attributed to treatment with targeted therapies. The average time between tumor diagnosis and symptom onset was 114.45 ± 147.72 weeks, while the time between treatment initiation and symptom onset was 25.35 ± 31.32 weeks (Figure 1). Regarding the treatment received, 65.5% received corticosteroids as indicated by Rheumatology, with an average prednisone dose in the last 6 months of 5.86 ± 7.18 mg. 27.3% received infiltrations, 34.5% DMARDs (23.6% methotrexate and 10.9% hydroxychloroquine), and only 2 patients (3.6%) biologics. In 7 patients (12.7%), immunotherapy had to be withdrawn. 48% died with an average time from the start of immunotherapy to death of 153.14 ± 96.61 weeks.

Conclusion: Most rheumatological manifestations are derived from treatment with PD-1 inhibitors, with symptoms appearing early after treatment initiation. A high percentage of patients respond to corticosteroids, although some require DMARDs, biologics, or even discontinuation of immunotherapy due to severe manifestations.

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Figure 1.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.