Characteristics, Prognosis and Reasons for Opting-Out of Treatment in Patients with Untreated Pancreatic Cancer

<i>Background:</i> About 40% of patients with pancreatic cancer (PC) are left untreated. Identification of the modifiable factors for opting out could increase the number eligible for treatment. <i>Methods:</i> We first assessed the completeness of registration. Next, we identified patients residing in the North Denmark Region, included 2023/24 in the Danish Pancreas Cancer Database (DPCD), registered as "no treatment". We supplemented register data with health record data, including reasons for opting out of treatment. <i>Results:</i> Registration in DPCD was complete compared to the National Clinical Cancer Database, except for one patient. Six patients had other tumors. Of a total of 91 patients, 79% were >75 years old, 2/3 were in performance status (PS) > 2, more than half were socially or physically fragile, while 42% had significant comorbidity. Only 20% were referred to an oncologist. The median overall survival was 2 months, and the 1-year survival was 6%. Clinical stage and PS were prognostic in multivariable analysis. In 70%, poor PS was a reason for opting out of treatment, while 11% declined treatment without objective reasons. <i>Conclusions:</i> Poor PS, frailty, or patients' wishes explained 89% opting out of treatment. On a patient level, modifiable factors seem limited in this population.