Single-institutional analysis of patients with clear-cell papillary renal cell carcinoma

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Background: Recently clear cell papillary renal cell carcinoma (cpRCC) has been recognized as new histologic subtype with immunohistochemical profiles that differentiate it from clear cell (ccRCC) and papillary (pRCC) RCC. Several previous studies highlighted the indolent behaviour of this entity in the reported cases. Our primary objective is to further elucidate the genomic and clinical characteristics of cpRCC. Methods: 44 patients with cpRCC were selected from the MSKCC database with surgery performed between 2007 and 2014. Only tumors with appropriate histological configuration and immunohistochemically confirmed CAIX and CK7 positivity and CD10 negativity were included. Whole exome sequencing (WES) was performed on 5 cpRCC tumor samples and one sample was analyzed by next-generation sequencing (MSK-IMPACT). A further comparison was made to 825 ccRCC and 219 pRCC tumors with initial pT1 diagnosis from our institutional database. Differences in the variables across groups were analyzed with the Chi-Square and the Kruskal–Wallis tests. To visualize and test the survival distribution differences, we used Kaplan–Meier plots and Log-rank tests. Results: Sequencing did not reveal VHL mutations or other known driver mutations commonly seen in ccRCC or pRCC and no recurrent mutations were identified. The median follow up period for cpRCC was 27 months, for ccRCC 59 months and for pRCC 63 months. cpRCC frequently co-occured with ccRCC or other RCC subtypes (17/44 cases). Female patients developed cpRCC significantly more frequently than ccRCC or pRCC (47.7% P<0.001) and Kruskal-Wallis test revealed differences in tumor size between the 3 groups (cpRCC median size 2.5 cm, P<0.001). Recurrence, metastatic development and death from kidney cancer was observed in ccRCC (3.7%, 2.3% and 0.8%) and in pRCC (4.5%, 1.8% and 2%), but not in the cpRCC cohort. Conclusions: cpRCC is genomically distinct from ccRCC and pRCC and lacks driver mutations commonly associated with aggressive disease. The tumors tend to present smaller than other RCC subtypes, commonly co-occur with other RCCs and disproportionately affect women. Extended follow-up of larger cohorts is necessary to confirm the true indolent nature of cpRCC.

PVT1 Exon 9: A Potential Biomarker of Aggressive Prostate Cancer?

Prostate cancer (PCa) is the most commonly diagnosed cancer as well as the greatest source of cancer-related mortality in males of African ancestry (MoAA). Interestingly, this has been shown to be associated with single nucleotide polymorphisms around regions 2 and 3 of the 8q24 human chromosomal region. The non-protein coding gene locus Plasmacytoma Variant Translocation 1 (PVT1) is located at 8q24 and is overexpressed in PCa and, therefore, is also a candidate biomarker to explain the well-known disparity in this group. PVT1 has at least 12 exons that make separate transcripts which may have different functions, all of which are at present unknown in PCa. Our aim was to determine if any PVT1 transcripts play a role in aggressiveness and racial disparity in PCa. We used a panel of seven PCa cell lines including three derived from MoAA. Ribonucleic acid extraction, complementary deoxyribonucleic acid synthesis, and quantitative polymerase chain reaction (qPCR) were performed to evaluate expression of all 12 PVT1 exons. Each qPCR was performed in quadruplicates. At least four separate qPCR experiments were performed. Expression of PVT1 exons was inconsistent except for exon 9. There was no significant difference in exon 9 expression between cell lines derived from Caucasian males (CM), and an indolent cell line derived from MoAA. However, exon 9 expression in the aggressive MDA PCa 2b and E006AA-hT cell lines derived from MoAA was significantly higher than in other cell lines. Consequently, we observed differential expression of exon 9 of PVT1 in a manner that suggests that PVT1 exon 9 may be associated with aggressive PCa in MoAA.

Salvage surgery after failed treatment of synthetic mesh sling complications

PURPOSE

We report our experience with the diagnosis and treatment of refractory synthetic sling complications in women.

MATERIALS AND METHODS

This is a retrospective study of consecutive women with failed treatments for mesh sling complications. Before and after surgery the patients completed validated questionnaires and voiding diaries, and underwent uroflow with post-void residuals, pad test, cystourethroscopy and videourodynamic studies. Treatment was individualized, and results were subdivided into the 2 groups of conditions and symptoms. Outcomes were assessed with the Patient Global Impression of Improvement with success classified as a score of 1, improvement as 2 to 3 and failure as 4 to 7.

RESULTS

A total of 47 women 35 to 83 years old (mean 60) had undergone at least 1 prior operation (range 1 to 4) to correct sling complications. Original sling composition was type 1 mesh in 36 patients and types 2 and 3 in 11. Surgical procedures included sling incision, sling excision, urethrolysis, urethral reconstruction, ureteroneocystotomy, cystectomy and urinary diversion, and enterocystoplasty. Median followup was 2 years (range 0.25 to 12, mean 3). Overall a successful outcome was achieved in 34 of 47 patients (72%) after the first salvage surgery. Reasons for failure were multiple for each patient. Of the 13 patients with treatment failure 9 subsequently underwent 14 operations. Success/improvement was achieved in 5 women (56%) after continent urinary diversion (1), continent urinary diversion and cystectomy (1), partial cystectomy and augmentation cystoplasty (1), biological sling and sinus tract excision (1), and vaginal mesh excision (1).

CONCLUSIONS

Success after the initial failure of mesh sling complications repair is possible but multiple surgeries may be required. Each symptom should be addressed separately.

Rectal biopsy for Hirschsprung's disease--are we performing too many?

BACKGROUND

Rectal biopsy is considered the gold standard for the diagnosis of Hirschsprung's disease. The aim of this study was to evaluate the outcome of rectal biopsies performed in our institution, and to determine whether we are performing an adequate number of biopsies in patients presenting with features suggestive of this disease.

METHODS

A retrospective analysis was conducted of patients who underwent rectal biopsy to exclude Hirschsprung's disease over a seven year period between 2000 and 2006. The histological diagnosis of Hirschsprung's disease was made using haematoxylin and eosin as well as acetylcholinesterase on frozen section. Patients were grouped into three age categories: neonates (group A), infants (group B) and those over 1 year of age (group C). The results of the biopsies were compared between groups.

RESULTS

A total of 668 patients underwent rectal biopsy. 18 samples were insufficient. Based on the histological studies of 650 suitable samples, 73 (11%) were positive and 577 (89%) were negative for Hirschsprung's disease. Of the 73 positive biopsies, 34 (47%) were from group A, 20 (27%) from group B and 19 (26%) from group C. The percentage of positive biopsies was much higher in group A with 29% (34 out of 118) compared to group B with 15% (20 out of 135) and group C with 5% (19 out of 395). Three complications of minor rectal bleeding occurred.

CONCLUSIONS

With 3 complications and 18 insufficient samples out of 668, rectal biopsy is a safe procedure and remains the gold standard for the diagnosis of Hirschsprung's disease, despite the large number of negative biopsies. Contrary to some reports in the literature which question the need for rectal biopsy in those presenting after the neonatal period, 53% of our positive diagnoses were made in children presenting after this period, with 19 positive biopsies out of 395 (5%) performed in children above the age of 1 year.