Abstract 1177P
Background
Elderly patients with neuroendocrine neoplasms have a worse survival and are undertreated in comparison to younger patients. Platinum and etoposide chemotherapy is the standard of care for poorly differentiated grade 3 neuroendocrine carcinoma (NEC). Because of the more favorable toxicity profile, carboplatin is often preferred over cisplatin in the elderly population, however still shows significant hematologic side effects. Efficacy and toxicity of carboplatin and etoposide (CE) in elderly NEC patients has not been analyzed so far. Furthermore, an optimal dosing strategy has not yet been established.
Methods
Retrospective analysis of all patients aged 70 years or older with extrapulmonary NEC in the NEN database of our center, treated with CE between 01/2013 and 12/2019. Progression-free (PFS) and overall survival (OS) were calculated from start of chemotherapy.
Results
In a total of 47 patients, median age was 74 years (range 70-85), median Ki67 70 %. Most common primary tumors were unknown (n=13), prostatic (n=8), pancreatic (n=7), esophagogastric (n=7) and colorectal (n=6). 12.7 % of patients had switched from a cisplatin-based protocol because of toxicity. Upfront dose reduction of CE was performed in 51.1 % of patients, sequential dose reduction was necessary in 10.6 %. G-CSF support was applied in 6 patients upfront, and became necessary during treatment in another 7. Overall response rate was 57.7 %, disease control rate 68.8 %. Median PFS was 5.8 months, median OS 32.9 months. Patient with upfront dose reduction showed a similar PFS to fully dosed patients (5.8 vs. 6.3 months, p=0.876). However, patients needing sequential dose reduction showed a strong trend towards a shortened PFS (2.0 months, p=0.059). Grade 3/4 toxicity was hematologic in 38.3 % and non-hematologic in 8.5 % of cases. There was only one case of toxicity-related treatment discontinuation and no treatment-related deaths.
Conclusions
Carboplatin and etoposide is a safe and effective treatment for elderly patients with NEC. Toxicity is well manageable with dose reduction and G-CSF support. However, regarding efficacy, an upfront dose reduction should be preferred over a dose reduction strategy reacting to toxicities.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
National Center for Tumor Diseases Heidelberg.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.