SUN-343 Mortality in Pheochromocytoma after Radical Surgery: Danish National Data over a Period of 40 Years

Background Pheochromocytomas and catecholamine-secreting paragangliomas (PPGL) are rare catecholamine-producing tumors. Due to the rarity, limited data on prognosis exists. Here, we present national data on mortality for radically operated patients compared to the background population over a period of 40 years. Materials and methods We have previously identified a national cohort of 588 PPGL patients diagnosed in Denmark 1977-2016. After excluding 80 patients diagnosed post-mortem, we found that out of 508 patients diagnosed alive, 479 (94%) underwent radical surgery. Each operated patient was matched on birth year, age and sex with 100 random controls from the general population. PPGL patients and comparison cohort members were then followed from date of surgery (or matched index date) to date of death, emigration or 31(st) of December 2016. Mortality rate-ratios (MRR) were calculated in patient-comparisons strata using Cox regression and adjusted for Charlson Comorbidity Index (CCI). CCI was determined using diagnosis codes registered before time of PPGL diagnosis (or matched index date). To identify prognostic factors, we obtained health records and analyzed clinical data in a geographic subgroup of patients (N=162). Results Operated PPGL patients had a median age of 55 years (Q1-Q3 42-65) and 56% were female. 26% of PPGL patients had a Charlson Comorbidity Index of 2 or more, compared to only 9% in the comparison cohort, with a higher proportion of patients registered with cardiovascular disease (19% vs 7%), cancer (16% vs 5%) and with diabetes (12% vs 3%). Median follow-up time for patients was 7.2 years (Q1-Q3 3.4-15.6), with 10- and 20-year survival after surgery of 78% (95% CI 73-82) and 64% (95% CI 57-69), respectively. MRR for PPGL patients was 1.8 (95% CI 1.5-2.2) compared to the comparison cohort and 1.4 (95% CI 1.2-1.7) when adjusted for CCI. In the subcohort of PPGL patients with available clinical data (N=162), we found, that patients diagnosed with PPGL due to diagnostic work-up for secondary hypertension (N=27) had the highest mortality after surgery with an adjusted MRR of 3.1 (95% CI 1.7-5.8) compared to these patients’ matched comparison cohorts. Adjusted MRR was 0.9 (95% CI 0.4-1.8, N=49) for patients evaluated for paroxysmal symptoms, 1.0 (95% CI 0.2-4.6, N=16) for patients diagnosed due to hereditary PPGL in family or after syndromic presentation, 1.3 (95% CI 0.7-2.2, N=58) for adrenal incidentalomas, and 2.2 (95% CI 0.9-4.9, N=10) in patients diagnosed due to other causes. Conclusion PPGL patients undergoing radical curative surgery have a higher mortality compared to the background population even when considering their higher comorbidity index at time of diagnosis. Especially patients diagnosed due to work-up for secondary hypertension have an increased mortality. These results indicate that radical surgery might not completely reverse the harmful effects of PPGL.