Abstract 53P
Background
TET are associated with autoimmune disorders (AID) in up to 30% of patients (pts). However, there have been wide variations in the reported prevalence of AID in TET pts in small single-center series. RYTHMIC (Réseau tumeurs THYMiques et Cancer) is a French network mandated to systematically discuss every case of TET. We aimed to describe risk factors of AID in a large French population.
Methods
RYTHMIC database, hosted by IFCT (Intergroupe Francophone de Cancérologie Thoracique), prospectively includes all consecutive pts with a diagnosis of TET discussed in French national or regional tumor boards. We analyzed epidemiologic, clinical and pathological characteristics of pts with TET’s related AID.
Results
From January 2012 to December 2019, 2909 pts were included in the registry. The Median Age at diagnosis was 63,5 (range 9 to 91). There were 590 (20.2%) events of AID in 552 pts, mainly females (53.4%). 21 pts (3.8%) had more than 1 AID. AID events are represented in the table. Diagnosis of AID was either done at tumor diagnosis (n=477, 81%), before diagnosis (n=75, 12.6%) or during follow up (FU) (n=38, 6.4%). 21/411 (5.1%) pts have subclinical myasthenia gravis (i.e. Ach-R positive antibodies without symptoms). In 8.8% (25/283) of pts, AID occurred at recurrence. Thymoma B2 has the highest prevalence of AID (n=187/541, 34.6%) and thymic carcinoma (TC) (n=11/248, 4.4%) the lowest. Overall, presenting AIDs was an independent good prognostic factor for relapse (HR=0,75, 95%CI[0,58-0,99]; p=0,04) but not for survival. There was some heterogeneity among AID since pts presenting Good’s syndrome and neuropathy had higher risk of relapse (HR=4.2, 95%CI[1.8-9.8]; p=0.001 and HR=5.9, 95%CI[1.06-20.17]; p=0.004 respectively). Among pts with AID, the risk of relapse was higher with B1 and B2 subtypes (OR=3, p=0.04 and OR=1.7, p=0.19; respectively). Surgery improved the AID outcome in pts with AB TET (OR=7.4, p=0.04). TC showed risk for AID during FU (OR=1.5, p=0.5). Table: 53P
| AID (n=590) | ||
| N | % | |
| Myasthenia Gravis | 411 | 69.6% |
| Red cell aplasia | 17 | 2.8% |
| Good’s Symdrome | 33 | 5.6% |
| Thyroiditis | 20 | 3.4% |
| Lupus | 26 | 4.4% |
| Arthritis | 13 | 2.2% |
| Glomerulonephritis | 8 | 1.3% |
| Neuropathy | 11 | 2% |
| Sjögren syndrome | 5 | 1% |
| Dermatomyositis | 9 | 1.5% |
| Others# | 37 | 6.2% |
Table # Others: Hemolytic Anemia (n=4), Encephalitis (n=3), Vasculitis (n=2), colitis (n=2), Sclerodermia (n=1), thrombocytopenia (n=2), hepatitis (n=1), Behçet disease (n=1), chronic pruritus (n=1), vitiligo (n=2), myocarditis (n=1), Ankylosing spondylitis (n=2), Sarcoidosis (n=1), others (n=14).
Conclusions
The prevalence of AID in pts with TET was 20.2%. Diagnosis of AID can be subclinical and delayed compared to the diagnosis of TET, sometimes as a recurrence event including TC. Immunotherapy indication should be carefully assessed in pts with TET other than TC with a tight FU.
Legal entity responsible for the study
IFCT and RYTHMIC network.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.