Beschreibung:
<jats:p> e13634 </jats:p><jats:p> Background: Cancer patients have an increased risk of developing secondary primary neoplasia (SPN) compared to the general population. These multiple primary malignancies (MMs) represent an increasing challenge for patients and physicians. So far, little is known about risk factors, patient characteristics, and survival. The study’s purpose was to obtain an overview of the occurrence and distribution of MMs and the outcome and prognosis of affected patients reporting to a large cancer center in Germany. Methods: The cancer registry data base of the Charité Comprehensive Cancer Center was queried for patients, which had their first cancer diagnosis between 01.01.2009 - 31.01.2010 and consecutively developed at least one more primary cancer within the follow-up period till 31.03.2019. For defining MM the rules from the Surveillance, Epidemiology, and End Results (SEER) Program were used. General tumor and patient characteristics as well as outcome were analyzed. Results: In total, 231 patients (155 male; 76 female) were included in the final analysis. Out of the 231 patients, 203 (87.9 %) presented with 2 primary tumors, 27 patients (11.7 %) with 3 and 1 patient (0.4%) with more than three. MMs occurred mostly in patients > 65 years (59.3%) and between 50-64 years (30.3%). According to the SEER definition 75.3% of the patients had metachronous and 24.7% had synchronous MMs. Most male patients presented initially with cancer of the bladder and the urinary tract (20.6%) and developed SPN in the prostate and the testicles (53.1%). The second most common initial cancer in this cohort was cancer of the prostate and testicles (18.1%) and the subsequent developed SPN was cancer of the bladder and the urinary tract (28.6%). For female patients the most common initial diagnosis was breast cancer (32.9%) followed by breast cancer as SPN in 60%. Overall, most frequent SPN were cancer of the prostate and testicles (13.4%), cancers of the lung and trachea (12.6%), and breast cancer (10.4%). Most patients (37.7%) developed the SPN within the 1st year and 28.6% after 5 years or later. Patients with synchronous MMs had a more than 40 months shorter OS than patients with the metachronous MM (79.00 ± 14.58 months vs. 122.00 ± 9.66 months). Conclusions: We could show that most MMs develop within the first year but that there is another peak after 5 years. However, it is still unclear how often SPN are misinterpreted as progressive disease. Therefore, further analyses and close follow-up are necessary. </jats:p>