Heterogeneity of cancer prevalence in young adults in the post–COVID-19 era: A multicenter real-world analysis.

Abstract

e22597 Background: COVID-19 exposure has been linked to persistent immune dysregulation, inflammatory signaling, and epigenetic changes whose role in cancer biology remains unclear. This study evaluated temporal differences in early-onset cancer (EOc) prevalence across major cancer groups in the pre- and post-pandemic eras. Methods: De-identified patient data from the TriNetX database; a federated electronic medical record was used to collect the number of patients diagnosed with various cancers. Data was divided into pre-COVID (2014-2019) and post-COVID (2020-2025) groups. The period between 7/1/2019-6/30/20 was excluded given ambiguity of COVID-19 diagnoses in the US during this time. Patients ≥18 years with malignant neoplasms of digestive organs (C15-26), bronchus and lung (C34), soft tissue sarcomas (C49), breast (C50), female genital organs (C51-58), male genital organs (C60-63), urinary tract (C64-68), reticuloendothelial groups (C81-96) were selected in each period. Groups were further stratified by age ≤50 years (EOc) and >50 years. Chi-square and rate ratios were used for statistical analysis. Results: A total of 2,106,086 patients were included in the 2014–19 group and 2,904,405 patients in the 2020-25 group. Patients with >1 malignancy of interest were excluded in individual group analyses. EOc accounted for 6.686% of 2014-19 group and 9.181% of 2020-25 group. Due to large sample sizes, p < 0.001 was deemed significant. The proportion of EOc was significantly increased in the 2020-25 across all groups (p < 0.001) except in the soft tissue sarcoma group ( p = 0.0247). Upon stratification, breast cancer had the highest EOc burden in post-COVID period, followed by gastrointestinal and lung cancers. Urinary tract and female genital groups showed a moderate rise in EOc, while male genital and reticuloendothelial groups had mild increases (p < 0.001, rate ratio ~1). To account for earlier breast cancer diagnoses compared to other groups, the age cut-off for EOc was lowered to ≤40 years. The EOc rate ratio for breast cancer remained high at 2.824 [CI: 2.727–2.925] in 2020-25 with this lowered cut-off. Conclusions: The aftermath of the COVID-19 pandemic has seen increasing cases of younger adults with primary solid malignancies. Heterogeneity among cancer sub-groups, especially a two-fold rise in proportion of early-onset breast cancer, is suggestive of a molecular mechanism rather than system-level differences in health care access. Further studies are needed to clarify mechanisms to improve current screening guidelines. Cancer type EOc rate ratio – post vs pre-COVID [95% CI] Breast 2.0908 [2.0619 - 2.1200] Gastrointestinal 1.8952 [1.8598 - 1.9312] Lung 1.7486 [1.6690 - 1.8320] Urinary tract 1.4781 [1.4376 - 1.5197] Female Genital organs 1.4031 [1.3793 - 1.4273] Male Genital organs 1.0822 [1.0564 - 1.1086] Soft tissue 1.0293 [1.0037 - 1.0557] Reticuloendothelial 1.0275 [1.0167 - 1.0384]