1492: Prevalence and Risk Factors of Gynecologic Cancers in Female Patients with Systemic Lupus Erythematosus

Background/Purpose: Systemic Lupus Erythematosus (SLE) is a chronic systemic autoimmune disorder that is nine times more prevalent in women. Patients with SLE are at an overall increased risk of cancer and may additionally have an increased risk of specific female reproductive cancers. This increase in cancer risk may be attributed to factors such as chronic inflammation, immunosuppression with decreased clearance of oncogenic viral infections, or treatment medication exposure. Our objective was to investigate if specific SLE clinical disease characteristics and sociodemographic factors are associated with gynecologic cancer in female patients with SLE.

Methods: We conducted a retrospective study utilizing our institutional ongoing longitudinal registry with a study population which included females ≥18 years of age, meeting classification criteria for SLE, and non-SLE population-matched female controls. Sociodemographic information and medical history were obtained from patient interviews and medical record information recorded in the registry. SLE disease damage was measured using SLICC Damage Index (SDI), modified for this study by excluding malignancy from the total score. Gynecologic cancers included any cancer of the female reproductive tract. Statistical analyses were Chi-squared test, Fisher’s exact test, two-sided t-test, and ANOVA, as appropriate, with significance determined by p-values < 0.05.

Results: Table 1 shows baseline demographic characteristics of the study population, comparing patients with SLE (n=800) to controls (n=499). Overall malignancy prevalence was higher among patients (8.5%) compared to controls (3.6%, p< 0.001), including a higher prevalence of breast cancer and gynecologic cancer. Of the 800 included female SLE patients (Table 2), 68 (8.5%) had been diagnosed with cancer, 14 (20.6%) of which had gynecologic cancers. Older age at baseline, and history of nicotine use were associated with a significantly higher prevalence of cancer and gynecologic cancers. Although the patients with SLE were disproportionately Black (74.5%) compared to White (21.3%), patients with gynecologic cancer were more likely to be White (57.1%, p< 0.001). The modified SDI score was associated with gynecologic cancers (p=0.04), while SDI score >2 was associated with both overall cancer (p=0.002) and gynecologic cancers (p=0.004). No significant association was found with childhood onset of SLE, lupus nephritis, or exposure to specific SLE medications. While most of the studied serologic markers did not correlate with the presence of cancer, a positive association between the presence of antiphospholipid antibodies and gynecologic cancers was found (p< 0.001).

Conclusion: Our findings provide insight into which SLE disease characteristics may be associated with gynecologic cancers for our cohort of female patients with SLE. The primary SLE disease characteristic found to correlate with gynecologic cancers was a higher modified SDI, while no association was found with SLE treatment medications, although overall cancer numbers were low. These results support ongoing investigation into additional risk and preventative factors for gynecologic cancers in patients with SLE.