P504S is a recently described, prostate cancer-specific gene that encodes a protein involved in the beta-oxidation of branched chain fatty acids. A recent study has shown that immunohistochemical detection of P504S gene product is a sensitive and specific marker of prostatic carcinoma in formalin-fixed, paraffin-embedded tissues. We performed a detailed analysis of P504S protein expression in a large series of prostate and bladder specimens with special emphasis on staining in specific morphologic patterns of prostatic adenocarcinoma, posthormonal and radiation therapy cases, and invasive urothelial carcinoma. A total of 366 prostate needle core biopsies from 124 patients with prostate cancer, 10 biopsies from 2 patients without prostate cancer, 28 prostatectomy specimens (16 with specific morphologic patterns, 7 posthormonal therapy and 5 postradiation therapy specimens), 5 bladder specimens with invasive urothelial carcinoma, and a single transurethral resection specimen from a patient with hormonally treated prostate cancer and invasive urothelial carcinoma were stained with P504S monoclonal antibody at a 1:250 dilution using standard heat-induced epitope retrieval and avidin-biotin technique. Extent (0, no staining; 1+, 1-10% staining; 2+, 11-50% staining; 3+, > or =51% staining) and location (luminal, subluminal, and diffuse cytoplasmic) of immunoreactivity in carcinoma and benign tissues were recorded. A total of 153 of 186 biopsies (82%) with prostatic adenocarcinoma stained for P504S. Pseudohyperplastic, atrophic, ductal, and mucinous prostatic carcinomas stained similarly, as did cases treated with hormone or radiotherapy. In 81 of 377 (21%) foci of benign prostatic tissue there was staining that was almost always focal, faint, and noncircumferential. Seminal vesicles did not stain for P504S. Five of six (83%) specimens with invasive urothelial carcinoma had 2+ staining and one case had focal staining. We conclude that immunohistochemistry for P504S has potential utility in the diagnosis of prostate cancer, including those treated by hormones and radiation. Circumferential luminal to subluminal and diffuse cytoplasmic staining is the most specific staining pattern for prostatic carcinoma and is almost never associated with benign prostatic tissue. However, a negative P504S immunostain does not automatically rule out prostate cancer, as 18% of cases were negative. Additionally, occasional benign glands, high-grade prostatic intraepithelial neoplasia, atypical adenomatous hyperplasia, and urothelial carcinoma may express P504S. Therefore, we think that P504S is best used only in conjunction with strict light microscopic correlation and preferably with high molecular weight cytokeratin immunostaining.

Patients with hyperplastic polyposis have multiple hyperplastic polyps (HPs) and increased risk of colorectal carcinomas. Aberrant crypt foci (ACF) are postulated to be the earliest precursor lesions in colorectal carcinogenesis. We evaluated BRAF mutations by DNA sequencing in 53 ACF from patients with sporadic colorectal carcinomas and familial adenomatous polyposis, in 18 sporadic HPs from patients with resected colorectal cancer, and in 70 HPs, 4 serrated adenomas, 3 admixed hyperplastic-adenomatous polyps, 10 tubular adenomas, and 6 carcinomas from 17 patients with multiple/large HPs and/or hyperplastic polyposis. BRAF mutation status was compared with clinicopathological features and other genetic alterations by marginal logistic regression. BRAF mutation was present in only 2% of ACF and 6% of sporadic HPs. In contrast, BRAF mutation was present in 43% of HPs (P = 0.01 versus sporadic HPs), 75% of serrated adenomas, 33% of admixed hyperplastic-adenomatous polyps, 30% of tubular adenomas, and 33% of carcinomas from patients with multiple/large HPs and/or hyperplastic polyposis. BRAF mutation status in patients with multiple/large HPs and/or hyperplastic polyposis correlated with HPs from the same patient (odds ratio, 5.8; P = 0.0002) but associated with younger age (odds ratio, 0.83; P = 0.006 compared to older age), with a large HP (odds ratio, 22.5; P = 0.01 compared with patients with multiple HPs), with location of HPs in the right colon (odds ratio, 3.0; P = 0.03), and with methylation of the p16 gene and the MINT31 locus [odds ratio, 12.2 (P = 0.0001) and 4.4 (P = 0.02), respectively]. Our study shows that BRAF mutation status is heterogeneous among patients with multiple/large HPs and/or hyperplastic polyposis, suggesting differences in pathogenesis of HPs that indicate subsets within this phenotype.

BACKGROUND The authors conducted a two‐arm Phase II study of temozolomide to determine its efficacy and toxicity in patients with soft tissue sarcomas (STSs) who had received, had refused, or were not eligible for standard chemotherapy with doxorubicin and ifosfamide (Arm 1) and in patients with gastrointestinal stromal tumors (GISTs; Arm 2). Patients with GIST were eligible regardless of prior therapy before imatinib was available. METHODS Sixty patients were enrolled in the current study, 19 of whom had GISTs and 41 of whom had other STSs. The patients received temozolomide at a dose of 85 mg/m2 orally for 21 days followed by 7 days without treatment. Standard radiographic imaging after every two cycles was used to assess the treatment response. RESULTS Of the 39 patients in Arm 1, there was 1 complete response and 1 partial response of 39 evaluable patients, for a total response rate of 5% (95% confidence interval, 0–12%). The responses lasted 7 months and 8 months, respectively. In Arm 2, there was no response in 17 patients. The disease was stable in 22% of the patients with GISTs and 33% of the patients with other STSs. The median overall survival time was 26.4 months in patients with GISTs and 11 months in patients with other STSs. The median time to disease progression was 2.3 months in patients with GISTs and 3.3 months in patients with other STSs. Grade 3 and Grade 4 adverse effects (according to National Cancer Institute Common Toxicity Criteria) were rare and included fatigue (eight patients), anemia (six patients), constipation (four patients), neutropenia (four patients), and thrombocytopenia (four patients). CONCLUSIONS The data from the current study suggest that temozolomide is well tolerated but has only minimal efficacy and a limited role in the treatment of patients with STSs. Cancer 2003;98:2693–9. © 2003 American Cancer Society.

BACKGROUNDThe authors conducted a 2‐arm Phase II trial of 9‐nitrocamptothecin (9‐NC), an oral topoisomerase I inhibitor, to define response rates in patients with gastrointestinal (GI) leiomyosarcomas and other soft‐tissue sarcomas (STS).METHODSPatients were required to provide informed consent and have measurable disease, Zubrod performance status ≤ 2, and adequate organ function. 9‐NC was administered orally at 1.5 mg/m2 per day × 5 days every week. Response evaluation was performed at 8 weeks, and those with stable or responding disease continued treatment until maximal response was achieved. A total of 56 patients (30 females and 26 males) with a median age of 55 years (range, 19–79 years) were enrolled on the study. Seventeen patients were enrolled on the GI leiomyosarcoma arm; only 1 minor response, lasting < 8 weeks in a patient with liver metastases, was noted, and so this arm was terminated. Thirty‐nine patients were entered on the other STS arm.RESULTSThree patients achieved a partial response (response rate, 8%) for durations of 4, 6, and 13 months, respectively. Fourteen patients had stable disease for a median of 4 months (range, 2–8 months). Two patients died of disease during the first 2 months. Four other patients required hospitalization for nausea, vomiting, and dehydration. Other toxicities included diarrhea (36 patients, 5 with Grade 3 toxicity); fatigue (42 patients, 11 with Grade 3 toxicity); anorexia (32 patients, 1 with Grade 3 toxicity); nausea (37 patients, 2 with Grade 3 toxicity); vomiting (24 patients, 3 with Grade 3 toxicity); neutropenia (14 patients, 5 with Grade 3 toxicity); and thrombocytopenia (16 patients, 5 with Grade 3 or 4 toxicity).CONCLUSIONS9‐NC is well tolerated but inactive in GI leiomyosarcomas and has minimal activity in previously treated patients with STS. Cancer 2003;97:2848–52. © 2003 American Cancer Society.DOI 10.1002/cncr.11385