Effect of chemotherapy on somatostatin receptor detection with octreotide scintigraphy in hormone-refractory prostate cancer patients.

BACKGROUND: Neuroendocrine cells have been found in all stages of prostate cancer. Neuroendocrine differentiation of prostate adenocarcinoma is a possible target for therapeutic strategies, such as administration of GH analogs (e.g., somatostatin), especially in patients with hormone-refractory prostate cancer (HRPC). The presence of receptors for these drugs in tumor cells and tissues is essential and is assessed with 111In-octreotide scintigraphy (Octreoscan). The relationship between these receptors and chemotherapy, the new standard therapy for HRPC, is unknown. PATIENTS AND METHODS: 111In-octreotide scintigraphy was performed on 20 patients affected by HRPC, all with metastatic disease. Chemotherapy with a single agent was also administered to all patients. RESULTS: In 63% of the patients, all metastases were negative to Octreoscan. Several metastases were positive in 37% of patients only, compared to 94% previously described in a chemotherapy-naive population. CONCLUSION: Chemotherapy seemed to reduce the cellular receptors for somatostatin analogs.

Chemoimmunotherapy with low dose vinorelbine and interleukin-2 in treatment of patients with metastatic renal cell carcinoma.

Systemic therapies employed in patients with metastatic renal cell carcinoma (MRCC) include chemotherapy to immunomodulatory cytokines (interleukin 2 [IL-2], interferon alpha [INFalpha]), chemoimmunotherapy, adoptive immune therapy and anti-angiogenic therapy. Despite this range of treatment alternatives, the optimal therapy for MRCC patients is far from being established. Thus, attempts with novel therapeutic approaches implementing new drug combinations are justified. We conducted a phase II evaluation of a combination of vinorelbine and IL-2, both at low doses, in 30 patients with MRCC. The rationale of the combination was to damage the tumor tissue to the extent necessary to make it more immunogenic while, at the same time, to obtain an efficient immune response through the concomitant administration of IL-2. The treatment, given in different dose combinations and administration times, resulted feasible, with no renal, neurological or hematological toxicity. The overall survival of the whole group of patients is higher than that usually observed following treatment with immunotherapies (18.2 versus 13.3 months, respectively). While the limited number of treated patients does not allow advancing conclusions on the effective activity of the adopted protocol, the results observed are encouraging.

Randomized trial of fenretinide in superficial bladder cancer using DNA flow cytometry as an intermediate end point.

Retinoids have shown a potential activity in preventing tumor recurrence in superficial bladder cancer. We assessed the activity of the synthetic retinoid fenretinide in superficial bladder cancer using DNA flow cytometry and conventional cytology as surrogate biomarkers. A total of 99 subjects with resected superficial bladder cancer (pTa, pT1) were randomized to either fenretinide (200 mg day p.o. for 24 months) or no intervention. Cystoscopy and bladder washing for DNA flow cytometry end points (proportion of DNA aneuploid histograms, hyperdiploid fraction, and percentage of apoptotic cells) and proportion of abnormal cytological examinations were repeated every 4 months for up to 36 months. The primary study end point was the proportion of DNA aneuploid histograms after 12 months. This figure was 48.9% in the fenretinide arm and 41.9% in the control arm (odds ratio, 1.16; 95% confidence interval, 0.44-3.07). There was no difference in any other response biomarker between the two groups up to 36 months, nor was any biomarker able to predict recurrence risk. Recurrence-free survival was comparable between the arms (27 events in the fenretinide arm versus 21 in the control arm; P = 0.36). Twelve subjects in the fenretinide arm complained of diminished dark adaptability, and nine subjects in the fenretinide arm versus one control subject had mild dermatological alterations. We conclude that fenretinide showed a lack of effect on the DNA content distribution and the morphology of urothelial cells obtained in serial bladder washings. Recurrence-free survival was comparable between groups. Because our data are hampered by the lack of predictivity of the selected biomarkers, additional studies are necessary to assess the activity of fenretinide in preventing bladder cancer.

Assessment of DNA flow cytometry as a surrogate end point biomarker in a bladder cancer chemoprevention trial.

Although conventional cytology represents the most widely performed cytometric analysis of bladder cancer cells, DNA flow cytometry has, over the past decade, been increasingly used to evaluate cell proliferation and DNA ploidy in cells from bladder washings. We have investigated whether DNA flow cytometry and conventional cytology of epithelial cells obtained from bladder washings provide reliable surrogate endpoint biomarkers in clinical chemoprevention trials. We used cytometric and clinical data from a chemoprevention trial of the synthetic retinoid Fenretinide on 99 patients with superficial bladder cancer. A total of 642 bladder washing specimens obtained from the patients at 4 month intervals was analyzed. Intra-individual agreement and correlation of flow cytometric DNA ploidy (diploid vs. aneuploid), DNA Index, Hyper-Diploid-Fraction (proportion of cells with DNA content higher than 2C), and conventional cytologic examination, as assessed by kappa statistics and Spearman's correlation test, were poor from baseline through 24 months. Moreover, no correlation was found between DNA ploidy and cytology at each time point. The same results were obtained when the analyses were stratified by treatment group. In addition, the association between the results of bladder washing (by either DNA flow cytometry or cytology) and concomitant tumor recurrence was significant only for abnormal cytology, while neither biomarker was predictive of tumor recurrence at the subsequent visit. During the time of this study only four patients progressed to muscle-invasive bladder cancer, indicating the "low-risk" features of the patient population. We conclude that DNA flow cytometry and conventional cytology on epithelial cells obtained from bladder washings do not appear to provide suitable surrogate endpoint biomarkers during the early stages of bladder carcinogenesis.

Normal epithelial cells modulating HLA class I surface molecules are susceptible to lysis mediated by CD3(+) and CD3(-) "nonspecific" killer cells.

Natural killer (NK) cells and NK-like T cells have been described as efficiently lysing neoplastic cells derived from hematopoietic tumors. By modulating the expression of HLA class I surface molecules on normal epithelial cells, we also observed that nonneoplastic cells can efficiently be lysed by "nonspecific" effectors. Clonal analysis clearly demonstrates that the presence of HLA-specific inhibitory NK receptors, such as CD94, CD158a, and CD158b, described on NK cells, is responsible for the inhibitory signal. Thus, NK cells, as well as NK-like T cells, in the absence of HLA surface molecules on normal target cells, efficiently lyse epithelial cells.

Phenotypic, functional and molecular analysis of lymphocytes associated with bladder cancer.

Bladder-washing-derived lymphocytes (BWDL) from 67 patients with bladder cancer were studied. The large majority of samples contained a pure population of T lymphocytes, whereas B and NK cells were absent. A comparative analysis of bladder lymphocytes and peripheral blood lymphocytes (PBL), collected in parallel, showed that BWDL significantly differed from PBL. In vitro cultures of bladder lymphocytes were attempted on 21 samples but in vitro expansion was only possible on six patients treated with bacillus Calmette-Guérin (BCG). This finding indicates that BWDL are characterized by a severe proliferative defect. Nevertheless, the addition of BCG on bladder lymphocytes expanded in vitro enhanced their proliferation, suggesting that this population is sensitized against BCG antigen(s). The analysis of T cell receptor restriction patterns showed that bladder lymphocytes from patients under BCG treatment were oligoclonal. A possible explanation for the efficiency of the immune response and good clinical outcome in patients treated with BCG could be found in the high homology between some BCG antigens and human heat-shock proteins, which are overexpressed in transformed cells.