Ofer Nativ

MicroRNAs accurately identify cancer tissue origin

MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that is involved in oncogenesis and shows remarkable tissue specificity. Their potential for tumor classification suggests they may be used in identifying the tissue in which cancers of unknown primary origin arose, a major clinical problem. We measured miRNA expression levels in 400 paraffin-embedded and fresh-frozen samples from 22 different tumor tissues and metastases. We used miRNA microarray data of 253 samples to construct a transparent classifier based on 48 miRNAs. Two-thirds of samples were classified with high confidence, with accuracy >90%. In an independent blinded test-set of 83 samples, overall high-confidence accuracy reached 89%. Classification accuracy reached 100% for most tissue classes, including 131 metastatic samples. We further validated the utility of the miRNA biomarkers by quantitative RT-PCR using 65 additional blinded test samples. Our findings demonstrate the effectiveness of miRNAs as biomarkers for tracing the tissue of origin of cancers of unknown primary origin.

Reconsidering the necessity of ipsilateral adrenalectomy during radical nephrectomy for renal cell carcinoma

OBJECTIVES Ipsilateral adrenalectomy is traditionally advocated as part of radical nephrectomy performed for renal cell carcinoma. The current study addresses the controversy of whether ipsilateral adrenalectomy should be performed routinely during radical nephrectomy. METHODS A total of 225 patients were treated surgically for renal cell carcinoma over an 18-year period. Of these patients, 158 underwent nephrectomy and simultaneous ipsilateral adrenalectomy and the other 67 had sparing of the ipsilateral adrenal gland. A retrospective analysis of the medical records and assessment of the clinical and the pathologic data were performed. Rates of survival and progression were evaluated in a subgroup of 109 patients, further subdivided into 54 patients who underwent concomitant adrenalectomy and 55 patients with the ipsilateral adrenal preserved during surgery. RESULTS Histopathologic abnormalities were detected in seven adrenal specimens (4.4%); however, only 3 patients (1.9%) had involvement of the adrenal by renal cell carcinoma. All cases of adrenal involvement were detected by the preoperative imaging modalities. Ipsilateral adrenalectomy did not improve the outcome in comparison to adrenal preservation. CONCLUSIONS In view of the rarity of ipsilateral adrenal metastasis, the questionable prognostic merits of concomitant adrenalectomy, and the availability of accurate imaging modalities, we conclude that ipsilateral adrenalectomy is not necessary in the majority of the patients undergoing radical nephrectomy for renal cell carcinoma.

Long-term followup of patients less than 30 years old with transitional cell carcinoma of bladder.

A review of our records between 1970 and 1986 identified 22 patients with transitional cell carcinoma of the bladder who were less than 31 years old. Of these patients 7 were less than 20 years old (group 1) and 15 were 20 to 30 years old (group 2). The tumors usually were of low grade and low stage. Patients in group 1 had no recurrences, whereas 6 patients (40 per cent) in group 2 had recurrences. Upstaging occurred in 2 patients with tumor recurrence. It would appear that while transitional cell carcinoma of the bladder in patients less than 20 years old has a more favorable prognosis, in patients 20 to 30 years old the prognosis is poorer and similar to that observed in older patients.

Is it justified to avoid radical cystoprostatectomy in elderly patients with invasive transitional cell carcinoma of the bladder

Background. Although radical cystectomy is accepted by most urologists as the treatment of choice for invasive carcinoma of the bladder and age alone is not considered a contraindication for radical surgery, many consider radical major operations to be unsuitable for elderly patients.

The Frequency of Histopathological Abnormalities in Incidental Appendectomy in Urological Patients: The Implications for Incorporation of the Appendix in Urinary Tract Reconstruction

In 1980 Mitrofanoff described the use of the isolated appendix as an intermittent catheterization route to empty a continent urinary reservoir. The procedure was popularized and numerous variations on the same principle were reported. Presence of histopathological abnormalities in the appendix may limit its suitability for reconstructive purposes. We studied the frequency of incidental histopathological abnormalities in appendixes removed electively in 122 urological patients during a radical pelvic operation. The implications for incorporation of the appendix in urinary tract reconstruction are evaluated. A total of 38 patients (31.1%) had notable histological abnormalities of the appendix: 35 had fibrous obliteration of the lumen, 2 had carcinoid tumor and 1 had a mucocele of the appendix. The rate of abnormal appendixes was significantly higher in elderly patients (more than 70 years old). Incidental pathology of the appendix is a frequent finding that may affect the immediate results and the late outcome of urinary tract reconstruction using the appendix. When such strategy of urinary tract reconstruction is considered, potential histopathological abnormalities should be anticipated. The patients should be informed and aware of possible unexpected changes in the preplanned procedure, while the surgeon must be familiar with these alternative reconstructive methods.

Urinary Infections Following Transurethral Resection of Bladder Tumors—Rate and Source

The incidence of urinary infection and its source after transurethral resection of bladder tumors were investigated. Patients undergoing transurethral prostatectomy constituted the control group. All patients had proved preoperative sterile urine and did not receive any antimicrobial treatment. The incidence of urinary infection following transurethral resection of bladder tumors was 19.4 per cent, with an incidence of positive tumor chip cultures of 3.2 per cent. The incidence of urinary infection after transurethral prostatectomy was 32 per cent, with an incidence of positive prostate chip cultures of 8 per cent. We concluded that the source of urinary infection following transurethral resection of bladder tumors and transurethral prostatectomy in most cases is not from within the tissue but rather from perioperative manipulations.

Localized renal cell carcinoma treated by radical nephrectomy. Influence of pathologic data and the importance of dna ploidy pattern on disease outcome

Background. The course of patients with renal cell carcinoma may be considerably different. Approximately 50% with presumed localized disease have metastases after nephrectomy. Pathologic stage at diagnosis, histologic grade, and histologic type have been considered the most important predictors of prognosis. Nevertheless, subsets of patients within a specified stage and grade may have considerable differences in disease progression and survival.

Prophylactic antimicrobial treatment in transurethral prostatectomy How long should it be instituted

Eighty-one patients with proved preoperative sterile urine and undergoing transurethral resection of the prostate were studied. The patients were divided into 3 groups: group A received sulfamethoxazole-trimethoprim (ST) preoperatively and postoperatively for ten days; group B received ST in 2 divided doses, one pre- and one postoperatively; group C received no prophylaxis. In groups A and B, we found urinary infection in 3.8 per cent of patients compared with 32 per cent in group C. Performing prostatic chip cultures, we found that most urinary infections were unrelated to a prostatic source. When the prostate was infected, 75 per cent had infected urine postoperatively. We believe that prophylactic antimicrobial treatment should be given to all patients undergoing transurethral prostatectomy. However, it seems that immediate perioperative treatment suffices.

Semen Quality and Hormonal Status of Patients Following Testicular Torsion

Summary: 16 patients, 4 months to five years following unilateral torsion of the testis were evaluated as to semen quality and hormonal status.

Primary chondrosarcoma of the kidney.

Primary chondrosarcoma of the extraskeletal soft tissue is rare, usually occurring in the upper and lower extremities. We report the first case of this neoplasm arising in the kidney.