Extrapulmonary Small Cell Carcinoma: A Single Institution Review of Brain Metastases, Treatment Paradigms and Patient Outcomes

PURPOSE/OBJECTIVE(S)

Extrapulmonary small cell carcinoma (EPSCC) is a rare entity with 1,000 cases reported annually in the U.S. It can originate in a variety of sites outside of the lung, and even with locoregional disease, relapse is common, and survival is poor. Prophylactic cranial irradiation (PCI) can improve survival in small cell lung carcinoma, however in the setting of EPSCC its role has not been clearly defined. We offer a single institution retrospective review of EPSCC, outlining the incidence of brain metastases, treatment paradigms, and patient outcomes.

MATERIALS/METHODS

Patients with available records were identified from an institutional database. Demographic, disease-related, and treatment details were abstracted from the electronic medical record. Clinical outcomes were obtained by medical record review and brain metastases were identified through diagnostic imaging. Patients were classified as having brain metastases at diagnosis or in follow-up. Brain metastasis-free survival (BMFS) was defined as the duration of time from diagnosis to the development of brain metastases, and extracranial progression-free survival (ePFS), as the duration of time from diagnosis to progression of disease outside the brain. Time to event outcomes were summarized using the Kaplan-Meier method. Analyses were performed using R version 3.6.

RESULTS

In total, 68 patients met eligibility criteria for analysis. The majority were male (66%) and median age was 68. The most common primary sites were genitourinary (32%) and gastrointestinal/hepatobiliary (22%). Thirty-eight patients (56%) had diagnostic brain imaging at time of diagnosis, with brain metastases present in 5 (13%). Treatment was delivered to 53 patients (80%) and treatment modalities included chemotherapy (n = 46), radiotherapy (n = 21), and surgery (n = 18). Median follow-up was 9.3 months for all patients and 10.3 months for surviving patients. Overall, 12 patients were observed to have brain metastases: 5 at diagnosis and 7 in follow-up. The competing risk of death without brain metastases at 1 year was 51.5%. Four of 5 patients with de novo brain metastases received WBRT. Of the 7 patients with subsequent brain metastases, 1 received salvage WBRT and 3 received salvage SRS. In total, 49 patients died and median OS was 10.0 months. Those with brain metastases had no significant difference in OS when compared to those without brain metastases (10.8 months v. 9.4 months). There was no association between primary type and survival.

CONCLUSION

EPSCC is a rare entity that is most commonly diagnosed in the genitourinary system. In contrast to SCLC, the incidence of brain metastases is uncommon. No difference in survival was observed between patients with or without brain metastases. While retrospective studies must be interpreted with caution, our data suggest that the risks of PCI may outweigh the benefits. Further studies investigating the role of brain imaging surveillance, as well as the optimal management of brain metastases, is warranted.

Surveillance for Babesia odocoilei in Hunter-Harvested Wild-Elk (Cervus elaphus canadensis) from Pennsylvania, USA (2016-2017)

Babesia odocoilei is a tick-borne protozoal parasite which infects the erythrocytes of members of the families Cervidae and Bovidae. Infection can result in hemolytic anemia, lethargy, anorexia, and death. The reservoir host of B. odocoilei is the white-tailed deer (Odocoileus virginianus); however, infections with overt disease have only been documented in reindeer (Rangider tarandu tarandus), caribou (Rangider tarandu caribou) and captive elk (Cervus elaphus canadensis). Infected elk may remain asymptomatic, creating the risk for dissemination of the pathogen when elk are relocated. Additionally, infected asymptomatic elk may contribute to the spread of B. odocoilei in the local wildlife/captive population via feeding ticks. Information regarding endemic regions of B. odocoilei infection is limited due to frequent asymptomatic infections and a lack of targeted surveillance of B. odocoilei in wildlife. To obtain data on B. odocoilei infection in wild elk in Pennsylvania, we tested blood samples collected from 190 hunter-harvested wild elk between 2016 and 2017. Of the 190 blood samples tested, 18.4% (35/190) tested positive for Babesia spp. Genetic sequencing of the positive samples showed a 98.0–100.0% match for B. odocoilei. No other Babesia species were identified. Results of this study documents B. odocoilei infection within hunter-harvested wild elk from Pennsylvania.

UME6 is a key regulator of nitrogen repression and meiotic development

This report describes the identification, cloning, and molecular analysis of UME6 (CAR80/CARGRI), a key transcriptional regulator of early meiotic gene expression. Loss of UME6 function results in the accumulation of fully derepressed levels (70- to 100-fold increase above basal level) of early meiotic transcripts during vegetative growth. In contrast, mutations in five previously identified UME loci (UME1 to UME5), result in low to moderate derepression (2- to 10-fold increase) of early meiotic genes. The behavior of insertion and deletion alleles indicates that UME6 is dispensable for mitotic division but is required for meiosis and spore germination. Despite the high level of meiotic gene expression during vegetative growth, the generation times of ume6 mutant haploid and diploid cells are only slightly reduced. However, both ascus formation and spore viability are affected more severely. The UME6 gene encodes a 91-kD protein that contains a C6 zinc cluster motif similar to the DNA-binding domain of GAL4. The integrity of this domain is required for UME6 function. It has been reported recently that a mutation in CAR80 fails to complement an insertion allele of UME6. CAR80 is a gene required for nitrogen repression of the arginine catabolic enzymes. Here, through sequence analysis, we demonstrate that UME6 and CAR80 are identical. Analyses of UME6 mRNA during both nitrogen starvation and meiotic development indicate that its transcription is constitutive, suggesting that regulation of UME6 activity occurs at a post-transcriptional level.