Cholangitis and Interruptions of Neoadjuvant Chemotherapy Associate with Reduced Overall and Progression-Free Survival in Pancreatic Cancer.

BACKGROUND: Interrupting chemotherapy may explain the reduced overall survival (OS) in patients with pancreatic cancer (PC) with cholangitis. Endoscopic biliary decompression (BD) with metallic stents results in fewer chemotherapy interruptions and a lower cholangitis rate compared with plastic stents. We aimed to determine the impact of cholangitis, neoadjuvant treatment (NAT) interruptions and biliary stent choice on PC patients' survival. METHODS: We conducted a retrospective analysis of 162 patients with cancer of the head of the pancreas undergoing pancreatoduodenectomy after NAT and BD documenting progression-free survival (PFS) and OS. Data on BD, cholangitis, stent type, surgical radicality, and chemotherapy were collected. Survival was estimated based on the Kaplan-Meier method by using the log-rank test and multivariate Cox regression analysis. RESULTS: Median OS and PFS for patients with cholangitis (n = 33, 20%) were 26 and 8 months (95% confidence interval [CI] 20-32 and 5-10 months), respectively, compared with 36 and 17 months (95% CI 31-41 and 12-21 months; p < 0.001 for OS; p = 0.002 for PFS) for patients without cholangitis. Among patients without NAT interruptions median OS and PFS were 35 and 17 months (95% CI 31-40 and 12-21 months), falling to 26 and 7 months (95% CI 18-30 and 5-10 months) among those who experienced an NAT interruption caused by biliary stent failure (n = 26, 16%) (p = 0.039 for OS; p < 0.001 for PFS). We found no difference in OS or PFS between stent types. CONCLUSIONS: Cholangitis and NAT interruptions reduce OS and PFS among PC patients.

NTHL1 is a recessive cancer susceptibility gene.

In search of novel breast cancer (BC) risk variants, we performed a whole-exome sequencing and variant analysis of 69 Finnish BC patients as well as analysed loss-of-function variants identified in DNA repair genes in the Finns from the Genome Aggregation Database. Additionally, we carried out a validation study of SERPINA3 c.918-1G>C, recently suggested for BC predisposition. We estimated the frequencies of 41 rare candidate variants in 38 genes by genotyping them in 2482-4101 BC patients and in 1273-3985 controls. We further evaluated all coding variants in the candidate genes in a dataset of 18,786 BC patients and 182,927 controls from FinnGen. None of the variants associated significantly with cancer risk in the primary BC series; however, in the FinnGen data, NTHL1 c.244C>T p.(Gln82Ter) associated with BC with a high risk for homozygous (OR = 44.7 [95% CI 6.90-290], P = 6.7 × 10-5) and a low risk for heterozygous women (OR = 1.39 [1.18-1.64], P = 7.8 × 10-5). Furthermore, the results suggested a high risk of colorectal, urinary tract, and basal-cell skin cancer for homozygous individuals, supporting NTHL1 as a recessive multi-tumour susceptibility gene. No significant association with BC risk was detected for SERPINA3 or any other evaluated gene.

Pathogenic Variant Spectrum in Breast Cancer Risk Genes in Finnish Patients.

Recurrent pathogenic variants have been detected in several breast and ovarian cancer (BC/OC) risk genes in the Finnish population. We conducted a gene-panel sequencing and copy number variant (CNV) analysis to define a more comprehensive spectrum of pathogenic variants in BRCA1, BRCA2, PALB2, CHEK2, ATM, BARD1, RAD51C, RAD51D, BRIP1, and FANCM genes in Finnish BC patients. The combined frequency of pathogenic variants in the BRCA1/2 genes was 1.8% in 1356 unselected patients, whereas variants in the other genes were detected altogether in 8.3% of 1356 unselected patients and in 12.9% of 699 familial patients. CNVs were detected in 0.3% of both 1137 unselected and 612 familial patients. A few variants covered most of the pathogenic burden in the studied genes. Of the BRCA1/2 carriers, 70.8% had 1 of 10 recurrent variants. In the other genes combined, 92.1% of the carrier patients had at least 1 of 11 recurrent variants. In particular, PALB2 c.1592delT and CHEK2 c.1100delC accounted for 88.9% and 82.9%, respectively, of the pathogenic variation in each gene. Our results highlight the importance of founder variants in the BC risk genes in the Finnish population and could be used in the designing of population screening for the risk variants.

ß-catenin plus PROX1 immunostaining stratifies disease progression and patient survival in neoadjuvant-treated pancreatic cancer.

BACKGROUND: Wnt/ß-catenin signaling is a highly conserved signaling pathway that regulates the transcription factor PROX1. The role of ß-catenin and PROX1 in pancreatic cancer is ambiguous, as some studies have associated their expression with tumor regression and some with tumor progression. OBJECTIVE: We have investigated their expression in surgically treated pancreatic cancer patients receiving neoadjuvant therapy (NAT), and patients treated upfront with surgery (US). We furthermore compared the expression of ß-catenin and PROX1 between patients who had a good or poor response to NAT. METHODS: We evaluated ß-catenin and PROX1 expression through immunohistochemistry in 88 neoadjuvant and 144 upfront surgery patients by scoring the intensity of the immunopositivity as 0-3, corresponding to negative, weak, moderate, or strong. We developed a six-tier grading scheme for the neoadjuvant responses by analyzing the remaining tumor cells in surgical specimen histological sections. RESULTS: Strong ß-catenin immunopositivity associated with improved survival in the patients with good NAT-response (≤10% residual tumor cells) (Hazard ratio [HR] 0.26 95%, confidence interval [CI] 0.07-0.88 p = 0.030). Additionally, the combined moderate ß-catenin and PROX1 expression associated with improved survival (HR 0.20 95% CI 0.05-0-76 p = 0.018) among the good responders. Among the patients with a poor NAT-response (> 10% residual tumor cells), both strong ß-catenin immunopositivity and strong combined ß-catenin and PROX1 associated with shorter survival (HR 2.03 95% CI 1.16-3.55 p = 0.013, and HR 3.1 95% CI 1.08-8.94 p = 0.03, respectively). PROX1 alone was not associated with survival. CONCLUSIONS: Strong ß-catenin immunopositivity and combined strong or moderate ß-catenin and PROX1 immunopositivity associated with improved survival among the good NAT-responders and worse survival among the poor NAT-responders.

The expression and prognostic value of toll-like receptors (TLRs) in pancreatic cancer patients treated with neoadjuvant therapy.

OBJECTIVES: Toll-like receptors (TLRs) play a pivotal role in the immune system and carcinogenesis. There is no research on TLR expression and association with survival among preoperatively treated pancreatic cancer patients. We studied the expression intensity and prognostic value of TLRs in pancreatic cancer patients treated with neoadjuvant therapy (NAT) and compared the results to patients undergoing upfront surgery (US). METHOD: Between 2000 and 2015, 71 borderline resectable patients were treated with NAT and surgery and 145 resectable patients underwent upfront surgery at Helsinki University Hospital, Finland. We immunostained TLRs 1-5, 7, and 9 on sections of tissue-microarray. We classified TLR expression as 0 (negative), 1 (mild), 2 (moderate), or 3 (strong) and divided into high (2-3) and low (0-1) expression for statistical purposes. RESULTS: Among TLRs 1, 3, and 9 (TLR1 81% vs 70%, p = 0.008; TLR3 92% vs 68%, p = 0.001; TLR9 cytoplasmic 83% vs 42%, p<0.001; TLR9 membranous 53% vs 25%, p = 0.002) NAT patients exhibited a higher immunopositivity score more frequently than patients undergoing upfront surgery. Among NAT patients, a high expression of TLR1 [Hazards ratio (HR) 0.48, p<0.05] associated with a longer postoperative survival, whereas among US patients, high expression of TLR5 (HR 0.64, p<0.05), TLR7 (HR 0.59, p<0.01, and both TLR7 and TLR9 (HR 0.5, p<0.01) predicted a favorable postoperative outcome in separate analysis adjusted for background variables. CONCLUSIONS: We found higher immunopositive intensities among TLRs 1, 3, and 9 in NAT patients. A high TLR1 expression associated with a longer survival among NAT patients, however, among US patients, high expression intensity of TLR5 and TLR7 predicted a favorable postoperative outcome in the adjusted analysis.

Use of self-expandable metallic stents for endoscopic biliary decompression decreases stent complications in pancreatic cancer patients receiving chemotherapy.

BACKGROUND: Both plastic stents and self-expandable metallic stents (SEMSes) are used for endoscopic biliary decompression (BD) among patients with pancreatic cancer (PAC). Cholangitis or stent occlusion often interrupts or ends chemotherapy. We investigated cholangitis, stent occlusion, and chemotherapy interruption rates for SEMSes and plastic stents among patients receiving chemotherapy for PAC. MATERIALS AND METHODS: We retrospectively analyzed data for 293 PAC patients who received a biliary stent at Helsinki University Hospital during 2000-2017. Patients received chemotherapy as palliative treatment (PT: n = 187) or neoadjuvant treatment (NAT: n = 106). Among participants, 229 had a plastic stent (PT: n = 138, NAT: n = 91) and 64 had a SEMS (PT: n = 49, NAT: n = 15). RESULTS: Overall, 15.6% (n = 10) of patients with SEMSes (PT: 20.4%, n = 10, NAT: 0%) and 53.0% (n = 121) of patients with plastic stents (PT: 69.3%, n = 95, NAT: 28.5%, n = 26) experienced one or more stent complications (p < 0.001). Cholangitis developed in 6.3% (n = 8) of PT patients with SEMSes. No patients with SEMSes receiving NAT (n = 15) experienced cholangitis. However, 31.9% (PT: 42.8%, n = 59, p = 0.001; NAT: 15.4%, n = 14, p = 0.211) of patients with plastic stents developed cholangitis. Among all patients receiving NAT or PT, cholangitis interrupted chemotherapy 6 times (9.4%) in SEMS patients and 61 times (26.6%) in plastic stent patients (p = 0.004). Stent occlusion without cholangitis interrupted NAT or PT 2 times (2.1%) in SEMS patients and 31 times (13.5%) in plastic stent patients (p = 0.023). CONCLUSIONS: SEMS is recommended for BD among patients with PAC receiving chemotherapy. Among both PT and NAT patients, patients with SEMS experience a lower stent failure rate, lower rate of cholangitis, and fewer chemotherapy interruptions than patients with plastic stents.

Changes in CRP and CA19-9 during Preoperative Oncological Therapy Predict Postoperative Survival in Pancreatic Ductal Adenocarcinoma.

INTRODUCTION: Tumor and systemic inflammatory markers predict survival. This retrospective study aimed to explore the changes in CRP, CA19-9, and other routine laboratory tests during preoperative oncological therapy as prognostic factors in pancreatic ductal adenocarcinoma (PDAC). METHODS: Between 2000 and 2016, 68 borderline resectable PDAC patients received preoperative oncological therapy and underwent subsequent surgery at Helsinki University Hospital, Finland. We investigated changes in CRP, CA19-9, CEA, albumin, leukocytes, bilirubin, and platelets and examined the impact on survival. RESULTS: In the multivariate analysis, CRP remaining at ≥3 mg/L after preoperative oncological therapy predicted a poorer postoperative outcome when compared to CRP decreasing to or remaining at <3 mg/L (hazard ratio [HR] 2.766, 95% confidence interval [CI]: 1.300-5.885, p = 0.008). Furthermore, a CA19-9 decrease >90% during preoperative treatment predicted a favorable postoperative outcome (HR 0.297, 95% CI: 0.124-0.708, p = 0.006). In the Kaplan-Meier analysis, the median survival for patients with CRP remaining at <3 mg/L was longer than among patients with an increased CRP level at ≥3 mg/L (42 months vs. 24 months, p = 0.001). Patients with a CA19-9 decrease >90% or level normalization (to ≤37 kU/L) during preoperative treatment exhibited a median survival of 47 months; those with a 50-90% decrease, 15 months; and those with a <50% decrease, 17 months (p < 0.001). CONCLUSIONS: Changes in CRP and CA19-9 during preoperative oncological therapy predict postoperative survival.

Impact of histological response after neoadjuvant therapy on podocalyxin as a prognostic marker in pancreatic cancer.

Podocalyxin overexpression associates with poor survival in pancreatic cancer (PDAC). We investigated whether podocalyxin expression correlates with treatment response or survival in neoadjuvant-treated PDAC. Through immunohistochemistry, we evaluated podocalyxin expression in 88 neoadjuvant and 143 upfront surgery patients using two antibodies. We developed a six-tier grading scheme for neoadjuvant responses evaluating the remaining tumor cells in surgical specimens. Strong podocalyxin immunopositivity associated with poor survival in the patients responding poorly to the neoadjuvant treatment (HR 4.16, 95% CI 1.56-11.01, p = 0.004), although neoadjuvant patients exhibited generally low podocalyxin expression (p = 0.017). Strong podocalyxin expression associated with perineural invasion (p = 0.003) and lack of radiation (p = 0.036). Two patients exhibited a complete neoadjuvant response, while a strong neoadjuvant response (≤ 5% of residual tumor cells) significantly associated with lower stage, pT-class and grade, less spread to the regional lymph nodes, less perineural invasion, and podocalyxin negativity (p < 0.05, respectively). A strong response predicted better survival (HR 0.28, 95% CI 0.09-0.94, p = 0.039). In conclusion, strong podocalyxin expression associates with poor survival among poorly responding neoadjuvant patients. A good response associates with podocalyxin negativity. A strong response associates with better outcome.

Combining CRP and CA19-9 in a novel prognostic score in pancreatic ductal adenocarcinoma.

Inflammation promotes tumor progression, induces invasion and metastatic spread. This retrospective study explored CRP, CA19-9, and routine laboratory values as preoperative prognostic factors in pancreatic cancer patients. Between 2000 and 2016, there were 212 surgically treated pancreatic cancer patients at Helsinki University Hospital, Finland. Out of these, 76 borderline resectable patients were treated with neoadjuvant therapy (NAT); 136 upfront resected patients were matched for age and sex at a 1:2 ratio. We analyzed preoperative CRP, CA19-9, CEA, leukocytes, albumin, bilirubin and platelets. CRP and CA19-9 were combined into a prognostic score: both CRP and CA19-9 below the cut-off values (3 mg/l and 37 kU/l, respectively), either CRP or CA19-9 above the cut-off value, and finally, both CRP and CA19-9 above the cut-off values. Among all patients, median disease-specific survival times were 54, 27 and 16 months, respectively (p < 0.001). At 5 years, among patients with CRP and CA19-9 levels below the cut-off values, 49% were alive and 45% were disease-free. Among NAT patients the corresponding survival rates were 52% and 45% and among those undergoing upfront surgery 45% and 40%, respectively. This novel prognostic score combining CRP and CA19-9 serves as a useful preoperative tool estimating survival.

Recurrent moderate-risk mutations in Finnish breast and ovarian cancer patients.

Mutations in BRCA1 and BRCA2 genes predispose to breast and ovarian cancer (BC/OC) with a high lifetime risk, whereas mutations in PALB2, CHEK2, ATM, FANCM, RAD51C and RAD51D genes cause a moderately elevated risk. In the Finnish population, recurrent mutations have been identified in all of these genes, the latest being CHEK2 c.319+2T>A and c.444+1G>A. By genotyping 3,156 cases and 2,089 controls, we estimated the frequencies of CHEK2 c.319+2T>A and c.444+1G>A in Finnish BC patients. CHEK2 c.319+2T>A was detected in 0.7% of the patients, and it was associated with a high risk of BC in the unselected patient group (OR = 5.40 [95% CI 1.58-18.45], p = 0.007) and similarly in the familial patient group. CHEK2 c.444+1G>A was identified in 0.1% of all patients. Additionally, we evaluated the combined prevalence of recurrent moderate-risk gene mutations in 2,487 BC patients, 556 OC patients and 261 BRCA1/2 carriers from 109 families. The overall frequency of the mutations was 13.3% in 1,141 BRCA1/2-negative familial BC patients, 7.5% in 1,727 unselected BC patients and 7.2% in 556 unselected OC patients. At least one moderate-risk gene mutation was found in 12.5% of BRCA1 families and 7.1% of BRCA1 index patients, as well as in 17.0% of BRCA2 families and 11.3% of BRCA2 index patients, and the mutations were associated with an additional risk in the BRCA1/2 index patients (OR = 2.63 [1.15-5.48], p = 0.011). These results support gene panel testing of even multiple members of BC families where several mutations may segregate in different individuals.

Neoadjuvant therapy offers longer survival than upfront surgery for poorly differentiated and higher stage pancreatic cancer.

BACKGROUND: Neoadjuvant therapy for pancreatic cancer remains controversial. Our aim was to assess differences in survival, disease recurrence and histopathological tumor characteristics between patients treated with neoadjuvant therapy followed by subsequent surgery and patients undergoing upfront surgery. MATERIAL AND METHODS: Out of 399 consecutive pancreatic ductal adenocarcinoma (PDAC) patients operated at Helsinki University Hospital in 2000-2015, 75 borderline resectable patients were treated with neoadjuvant therapy. Resectable propensity scored patients (n = 150) underwent upfront surgery. Neoadjuvant therapy consisted of folfirinox, single gemcitabine or combined with cisplatin, nab-paclitaxel or capecitabine with or without radiation. Survival was calculated with Kaplan-Meier and compared with the Breslow test. Survival was determined from the start of treatment, being the first day of treatment for patients treated with neoadjuvant therapy and the date of surgery for others. RESULTS: Between 2000 and 2015 median disease-specific survival (DSS) [34 vs. 26 months, p = .016] and disease-free survival (DFS) [22 vs. 13 months, p = .001] were longer in patients treated with neoadjuvant therapy than in those undergoing upfront surgery. Survival differences were not significant in the 2000s but were, in turn, among patients treated in the 2010s with better survival for patients treated with neoadjuvant therapy [DSS 35 vs. 26 months, p = .008 and DFS 25 vs. 13 months, p = .001]. Especially patients with poorly differentiated G3 tumors [DSS 30 vs. 11 months, p = .004 and DFS 21 vs. 7 months, p = .001] and higher stage IIB-III [DSS 34 vs. 20 months, p = .006 and DFS 21 vs. 10 months, p = .001] had longer survival when treated with neoadjuvant therapy. CONCLUSIONS: PDAC patients treated with neoadjuvant therapy had longer DSS and DFS than those undergoing upfront surgery. Neoadjuvant therapy benefits especially borderline resectable patients with higher stage and poorly differentiated tumors.

Case-control analysis of truncating mutations in DNA damage response genes connects TEX15 and FANCD2 with hereditary breast cancer susceptibility.

Several known breast cancer susceptibility genes encode proteins involved in DNA damage response (DDR) and are characterized by rare loss-of-function mutations. However, these explain less than half of the familial cases. To identify novel susceptibility factors, 39 rare truncating mutations, identified in 189 Northern Finnish hereditary breast cancer patients in parallel sequencing of 796 DDR genes, were studied for disease association. Mutation screening was performed for Northern Finnish breast cancer cases (n = 578-1565) and controls (n = 337-1228). Mutations showing potential cancer association were analyzed in additional Finnish cohorts. c.7253dupT in TEX15, encoding a DDR factor important in meiosis, associated with hereditary breast cancer (p = 0.018) and likely represents a Northern Finnish founder mutation. A deleterious c.2715 + 1G > A mutation in the Fanconi anemia gene, FANCD2, was over two times more common in the combined Finnish hereditary cohort compared to controls. A deletion (c.640_644del5) in RNF168, causative for recessive RIDDLE syndrome, had high prevalence in majority of the analyzed cohorts, but did not associate with breast cancer. In conclusion, truncating variants in TEX15 and FANCD2 are potential breast cancer risk factors, warranting further investigations in other populations. Furthermore, high frequency of RNF168 c.640_644del5 indicates the need for its testing in Finnish patients with RIDDLE syndrome symptoms.

Metabolism of berry anthocyanins to phenolic acids in humans.

We studied the metabolism of berry anthocyanins to phenolic acids in six human subjects by giving them bilberry-lingonberry puree with and without oat cereals. Puree + cereals contained 1435 micromol of anthocyanins and 339 micromol of phenolic acids. The urinary excretion of measured 18 phenolic acids increased 241 micromol during the 48 h follow-up after the puree + cereals supplementation. The excretion peak of dietary phenolic acids was observed at 4-6 h after the puree + cereals supplementation and 2 h earlier after the supplementation of the puree alone. Homovanillic and vanillic acids were the most abundant metabolites, and they were partly produced from anthocyanins. No gallic acid, a fragmentation product of delphinidin glycosides, was detected, and only a very low amount of malvidin glycosides was possibly metabolized to syringic acid. Although anthocyanins were partly fragmented to phenolic acids, still a large part of metabolites remained unknown.

Consumption of juice fortified with oregano extract markedly increases excretion of phenolic acids but lacks short- and long-term effects on lipid peroxidation in healthy nonsmoking men.

Oregano has been shown to possess antioxidant capacity in various in vitro models and has thus been suggested to be potentially beneficial to human health, but studies in humans are lacking. The aim of this study was to investigate the bioavailability and the effects of Origanum vulgare extract supplementation on serum lipids and lipid peroxidation in healthy nonsmoking men. A four-week double-blinded supplementation trial was concluded in which volunteers (n = 45) were randomized to consume daily mango-orange juice (placebo), mango-orange juice enriched with 300 mg/d total phenolic compounds from oregano extract, or mango-orange juice enriched with 600 mg/d total phenolic compounds from oregano extract. The excretion of phenolic compounds was markedly increased in the higher phenolic group as compared to the placebo group, but no significant changes were observed in the safety parameters, serum lipids, or biomarkers of lipid peroxidation.

Ingestion of oregano extract increases excretion of urinary phenolic metabolites in humans.

Despite the promising antioxidant action of Lamiaceae herbs in vitro, human studies on these potential sources of dietary antioxidants have remained scarce. In this work, the phenolic acids recovered in human urine after single ingestion of Origanum onites extract were analyzed. The excretion was increased 4- and 2-fold during 0-24 and 24-48 h of the follow-up, respectively. The mean increase in the excretion of phenolic compounds exceeded the ingested amount of identified phenolic acids. The result can be partly explained by rosmarinic acid, the main identified phenolic constituent in the extract, as well as flavonoids present in minor amounts, presumably being metabolized into a double amount of simple phenolic metabolites. Furthermore, unidentified phenolic constituents in the extract partly contribute to the excretory increase. The main metabolite, p-hydroxybenzoic acid, was excreted rapidly. The results show that constituents of oregano extract and, in particular, their metabolites may contribute to the dietary intake of phenolic antioxidants.

Polyphenol-rich phloem enhances the resistance of total serum lipids to oxidation in men.

In humans, polyphenol supplementation studies have resulted in inconsistent findings in lipid peroxidation. Our aim was to investigate the effects of a 4-week consumption of polyphenol-rich phloem on serum lipids and lipid peroxidation in the hydrophilic fraction of serum and on isolated lipoproteins. We conducted a randomized double-blind supplementation study consisting of 75 nonsmoking hypercholesterolemic men. Participants consumed 70 g daily of either rye bread (placebo) or phloem-fortified rye bread containing 31 mg (low polyphenol, LP) or 62 mg (high polyphenol, HP) of catechins. The ex vivo susceptibility of total serum lipids and VLDL and LDL to oxidation after copper induction was measured as a lag time to the maximal oxidation rate at the baseline and after the supplementation. In the HP group, an increase in the oxidation resistance of total serum lipids was observed (11.4%), while no effect was seen in the LP group (-0.8%) or in the placebo group (-1.0%) (p = 0.007). No differences were observed in the oxidation resistance of VLDL and LDL between the study groups. The phloem also increased in vitro oxidation resistance of serum lipids and radical scavenging activity (DPPH.) in a dose-dependent manner. Our results suggest that polyphenols may inhibit lipid peroxidation in the hydrophilic fraction of serum.

Differing Effects of Two Angiotensin Converting Enzyme Inhibitors, Captopril and CI-906, on Diuresis and the Urinary Excretion of Kallikrein and Prostaglandins in Spontaneously Hypertensive Rats.

The effects of two angiotensin I convening enzyme inhibitors on the kallikrein-kinin system and prostanoids were studied in spontaneously hypertensive rats. The doses of captopril were 20, 50 and 100 mg/kg×day given twice daily, and those of CI-906 20 and 40 mg/kg once daily. Both drugs were equally effective in reducing the systolic blood pressure. Captopril increased urine volume dose-dependently (up to 3-fold with the largest dose). Only the larger dose of CI-906 was slightly diuretic. Captopril decreased the 24-h urinary excretion of kallikrein, while the excretion of the prostacyclin metabolite 6-keto-PGF1α was increased markedly and that of T × B2 to a lesser extent. CI-906 had no effect on the 24-h urinary excretion of kallikrein, 6-keto-PGF1α and T × B2. Both drugs tended to reduce PGE2 excretion. Captopril and CI-906 did not alter plasma kininogen levels. The marked renal effects of captopril may be caused by a strong local inhibition of converting enzyme in the kidneys. Captopril is mainly excreted unchanged in urine, and it is secreted actively by the proximal tubular cells. CI-906 is eliminated predominantly by biliary excretion. It is also possible that direct stimulation of prostacyclin formation by captopril may be involved in the diuretic action of the drug. However, as it was shown with CI-906, the increase in urine flow and the associated changes in urinary kallikrein and prostanoids are not necessary for the antihypertensive effect caused by the inhibition of converting enzyme.