Preemptive Appendicectomy at the Time of Pancreas Transplantation: Is It Necessary?

OBJECTIVES: Pancreas transplant is a major intraabdominal operation, and in most cases the graft is placed in the rightiliac fossa. At our center, preemptive appendicectomy is performed at the time of pancreas transplant to prevent any future risk in a complex transplant patient. The aim of this study was to review all histology reports from the removed appendices. MATERIALS AND METHODS: The histology reports from all incidental appendicectomies performed at pancreas transplant were reviewed. RESULTS: Between January 2001 and June 2016, 107 pancreas transplants were performed (86 simultaneous pancreas and kidney transplants, 11 pancreas after kidney transplants, and 10 pancreas transplants alone), and 65 appendix histology reports were available from this patient group. All were preemptive appendicectomies as none of the patients had symptoms to suggest acute appendicitis. Of the 65 appendix histologies, 43 (66.2%) were reported as normal. Twenty specimens (30.8%) showed fibrosis consistent with previous inflammation of the appendix, and 12 specimens (18.5%) showed fecal material in the lumen (1 due to an obstructing fecalith and another 2 showing luminal distension with feces). Three specimens (4.6%) showed lymphoid hyperplasia. There were 5 (7.7 %) unexpected findings upon histology. In review of histology reports, 1 patient had a 1.1-mm carcinoid tumor in an otherwise normal appendix, 1 had an Enterobius species worm infestation, 1 had focal endometriosis, 1 had crypt abscesses suggestive of inflammatory bowel disease, 1 had a metaplastic polyp, and 1 had melanosis coli of unknown clinical significance. There were no cases of overt acute appendicitis. No patients experienced a complication as a direct result of their appendicectomy. CONCLUSIONS: A policy ofroutine appendicectomy atthe time of pancreas transplant appears to be justified and safe.

Characterization of ERG, AR and PTEN gene status in circulating tumor cells from patients with castration-resistant prostate cancer.

Hormone-driven expression of the ERG oncogene after fusion with TMPRSS2 occurs in 30% to 70% of therapy-naive prostate cancers. Its relevance in castration-resistant prostate cancer (CRPC) remains controversial as ERG is not expressed in some TMPRSS2-ERG androgen-independent xenograft models. However, unlike these models, CRPC patients have an increasing prostate-specific antigen, indicating active androgen receptor signaling. Here, we collected blood every month from 89 patients (54 chemotherapy-naive patients and 35 docetaxel-treated patients) treated in phase I/phase II clinical trials of an orally available, highly specific CYP17 inhibitor, abiraterone acetate, that ablates the synthesis of androgens and estrogens that drive TMPRSS2-ERG fusions. We isolated circulating tumor cells (CTC) by anti-epithelial cell adhesion molecule immunomagnetic selection followed by cytokeratin and CD45 immunofluorescence and 4',6-diamidino-2-phenylindole staining. We used multicolor fluorescence in situ hybridization to show that CRPC CTCs, metastases, and prostate tissue invariably had the same ERG gene status as therapy-naive tumors (n=31). We then used quantitative reverse transcription-PCR to show that ERG expression was maintained in CRPC. We also observed homogeneity in ERG gene rearrangement status in CTCs (n=48) in contrast to significant heterogeneity of AR copy number gain and PTEN loss, suggesting that rearrangement of ERG may be an earlier event in prostate carcinogenesis. We finally report a significant association between ERG rearrangements in therapy-naive tumors, CRPCs, and CTCs and magnitude of prostate-specific antigen decline (P=0.007) in CRPC patients treated with abiraterone acetate. These data confirm that CTCs are malignant in origin and indicate that hormone-regulated expression of ERG persists in CRPC.