SAT-107 - Evolving Survival Patterns in Pituitary Adenocarcinoma: Insights from SEER Data Across Two Eras

Background: Pituitary adenocarcinoma is a rare and aggressive malignancy associated with poor survival and early mortality. Since 2010, advancements in imaging, surgical techniques, radiotherapy and the introduction of temozolomide-based therapy have changed clinical management. Nevertheless, the effect of these developments on population-level survival outcomes remains unclear. This study examines survival trends among patients aged 18–85 years diagnosed with pituitary adenocarcinoma, utilizing data from the Surveillance, Epidemiology, and End Results (SEER) Program spanning 2000 to 2019.

Methods: Data were extracted from the SEER-21 registry (2000–2019) using SEER*Stat version 9.0.42.2. Survival analyses were performed using the Kaplan–Meier method in SPSS version 24, comparing patients diagnosed in the 2011–2019 era with those diagnosed in the 2000–2010 era at 6, 12, and 36 months. Time truncation minimized bias from unequal follow-up. Survival differences between cohorts were assessed using the log-rank test within each truncated interval.

Multivariable Cox proportional hazards regression was conducted to identify factors independently associated with mortality when a significant survival difference was observed. Covariates included age, sex, race/ethnicity (White, Black, Hispanic, Asian/Pacific Islander, American Indian/Alaska Native), annual household income ( < $50,000, $50,000–$100,000, >$100,000), residential area (metropolitan and non-metropolitan) and diagnostic era (2011–2019 and 2000–2010). Statistical significance was set at p < 0.05.

Results: Truncated Kaplan–Meier analyses stratified by diagnostic era demonstrated a statistically significant difference in 6-month survival between patients diagnosed in 2011–2019 and those diagnosed in 2000–2010 (96.8% vs 88.1%; χ²(1)=5.03, p=0.025). The magnitude of the survival difference diminished with longer truncated follow-up and was no longer statistically significant at 12 months (95.7% vs 88.1%; χ²(1)=3.69, p=0.055) or at 36 months (86.2% vs 80.5%; χ²(1)=1.25, p=0.263).

A multivariable Cox proportional hazards model limited to the first 3 months of follow-up demonstrated that increasing age was independently associated with higher early mortality, with a 5% increase in risk per additional year of age (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.02–1.07; p=0.002). Sex, race/ethnicity, household income and residential area were not significantly associated with early mortality.

Conclusion: Early survival in pituitary adenocarcinoma appears to have improved in recent years, particularly during the first 6 months; however, longer-term outcomes remain largely unchanged. Given the rarity of this malignancy, these observations should be interpreted cautiously and suggest the need for further research to explore strategies that may enhance sustained survival.

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