CYP2D6 genotype predicts tamoxifen discontinuation and drug response: a secondary analysis of the KARISMA trial.

BACKGROUND: Guidelines regarding whether tamoxifen should be prescribed based on women's cytochrome P450 2D6 (CYP2D6) genotypes are conflicting and have caused confusion. This study aims to investigate if CYP2D6 metabolizer status is associated with tamoxifen-related endocrine symptoms, tamoxifen discontinuation, and mammographic density change. PATIENTS AND METHODS: We used data from 1440 healthy women who participated the KARISMA dose determination trial. Endocrine symptoms were measured using a modified Functional Assessment of Cancer Therapy - Endocrine Symptoms (FACT-ES) questionnaire. Change in mammographic density was measured and used as a proxy for tamoxifen response. Participants were genotyped and categorized as poor, intermediate, normal, or ultrarapid CYP2D6 metabolizers. RESULTS: The median endoxifen level per mg oral tamoxifen among poor, intermediate, normal and ultrarapid CYP2D6 metabolizers were 0.18 ng/ml, 0.38 ng/ml, 0.56 ng/ml and 0.67 ng/ml, respectively. Ultrarapid CYP2D6 metabolizers were more likely than other groups to report a clinically relevant change in cold sweats, hot flash, mood swings, being irritable, as well as the overall modified FACT-ES score, after taking tamoxifen. The 6-month tamoxifen discontinuation rates among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were 25.7%, 23.6%, 28.6%, and 44.4%, respectively. Among those who continued and finished the 6-month tamoxifen intervention, the mean change in dense area among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were -0.8 cm2, -4.5 cm2, -4.1 cm2, and -8.0 cm2 respectively. CONCLUSIONS: Poor CYP2D6 metabolizers are likely to experience an impaired response to tamoxifen, measured through mammographic density reduction. In contrast, ultrarapid CYP2D6 metabolizers are at risk for exaggerated response with pronounced adverse effects that may lead to treatment discontinuation.

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium.

BACKGROUND: Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. METHODS: Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. RESULTS: Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. CONCLUSION: Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.

Effects of three anti-TNF-alpha drugs: etanercept, infliximab and pirfenidone on release of TNF-alpha in medium and TNF-alpha associated with the cell in vitro.

Tumor necrosis factor-alpha (TNF-alpha) is a vital component of the inflammatory process and its aberrant over-expression has been linked to numerous disease states. New treatment strategies have sought to reduce circulating TNF-alpha, either with neutralizing anti-TNF-alpha binding proteins such as etanercept or via drugs that inhibit de novo TNF-alpha synthesis like pirfenidone. In the present study, we examined the effects of both classes of drugs on secreted and cell-associated TNF-alpha produced by THP-1 cells. All of the tested drugs significantly reduced secreted levels of bioactive TNF-alpha following stimulation with LPS as measured by bioassay. However, etanercept-treated cells had approximately six-fold higher levels of cell-associated TNF-alpha compared with that of the LPS-alone treatment group. Surprisingly, LPS+infliximab treated cells did not increase cell-associated TNF-alpha relative to the LPS-alone treatment. Pirfenidone significantly reduced both secreted and cell-associated TNF-alpha levels. These drug-related differences in cell-associated TNF-alpha may have broad implications in the future for the therapeutic uses of anti-TNF-alpha drugs in the management of TNF-alpha diseases.

TGFBR1(*)6A and Int7G24A variants of transforming growth factor-beta receptor 1 in Swedish familial and sporadic breast cancer.

Two common variants in transforming growth factor-beta receptor 1 (TGFBR1), TGFBR1(*)6A and Int7G24A, A allele, have been shown to act as low-penetrance tumour susceptibility alleles in several common cancers, including breast cancer. We evaluated the TGFBR1 9A/6A and Int7G24A variant frequencies in two breast cancer cohorts; a population-based cohort of breast cancer with defined family history (n=459) and in breast cancer patients from a familial cancer clinic (n=340) and in 856 controls from the Stockholm region. The familial patients from both cohorts were further divided into high- and low-risk familial breast cancer based on pedigree analysis. There was no overall association with either variant and breast cancer risk. The TGFBR1(*)6A allelic frequency was, however, higher in low-risk familial breast cancer (0.138), compared to controls (0.106; P=0.04). No significant difference was found in the high-risk familial (0.102) or sporadic cases (0.109; P=0.83 and 0.83, respectively). TGFBR1(*)6A carrier status was further associated with a high-grade sporadic breast cancer (odds ratio: 2.27; 95% confidence interval: 1.01-5.11; P=0.049). These results indicate that the TGFBR1(*)6A variant may be associated with an increased risk of low-risk familial breast cancer and might be a marker for poorly differentiated breast cancer. The Int7G24A variant was not associated with breast cancer risk or clinical presentation of the disease including prognosis in our material.

High incidence of skewed X chromosome inactivation in young patients with familial non-BRCA1/BRCA2 breast cancer.

BACKGROUND: A higher frequency of skewed X chromosome inactivation has been reported in a consecutive series of young patients with breast cancer compared with controls of a similar age. OBJECTIVE: To investigate the X inactivation pattern in patients with familial non-BRCA1/BRCA2 breast cancer (n = 272), BRCA1/BRCA2 germline mutations (n = 35), and sporadic breast cancer (n = 292). METHODS: X inactivation pattern was determined by polymerase chain reaction analysis of the highly polymorphic CAG repeat in the androgen receptor (AR) gene. The X inactivation pattern was classified as skewed when 90% or more of the cells preferentially expressed one X chromosome. RESULTS: Young patients with familial breast cancer had a significantly higher frequency of skewed X inactivation (11.2%) than young controls (2.7%) (p = 0.001). There was also a strong tendency for middle aged patients with sporadic breast cancer to be more skewed than middle aged controls (13.6% v 4.4%) (p = 0.02). No association between skewed X inactivation and breast cancer was found for the BRCA1/BRCA2 patients . CONCLUSIONS: Skewed X inactivation may be a risk factor for the development of breast cancer in both sporadic and familial breast cancer and may indicate an effect of X linked genes.

Pharmacokinetics of orally administered pirfenidone in male and female beagles.

Pirfenidone, a promising antifibrotic agent, was administered orally to dogs at 0, 40, 140, and 400 mg/kg/day. Serum was collected for pirfenidone assay at 0, 26 and 39 weeks of treatment. From the pirfenidone concentrations, pharmacokinetic parameters were determined for each dog at each treatment interval. The only significant differences because of gender were for concentration maxima. Unsurprisingly, there were many significant differences because of dose in concentration maximum and area under curve (AUC), and significant, positive linear correlations of both parameters with dose. There were few significant differences in time of maximal concentration and no correlation with dose. The mean +/- SE clearances were 1.99 +/- 0.13, 1.64 +/- 0.13 and 1.78 +/- 0.14 L/h/kg for doses of 40, 140, and 400 mg/kg, respectively, with no significant differences attributable to dose. There was an unexplained pattern in maximal concentration and AUC with regard to duration of treatment, with the parameters being highest at week 0, lowest at week 26, and intermediate at week 39. Clearance had the reverse pattern; time of maximal concentration had no pattern.

Antirheumatic effect of pirfenidone in a double blind clinical pilot trial in humans.

The antirheumatic effect of pirfenidone was compared with a positive control drug, oxyphenbutazone which is used in patients suffering from rheumatoid arthritis, in a double blind clinical trial in humans. The data collected in this pilot project revealed that pirfenidone was more effective (p < 0.025) than oxyphenbutazone in providing relief from arthritic pain. In addition, a greater number (p < 0.025) of patients reported favorable response to oral pirfenidone than oral oxyphenbutazone. However, there were no significant differences in the number of patients who dropped out from the trial and the number of patients who tolerated the drugs for 21 days of the trial between the pirfenidone and oxyphenbutazone groups. It was concluded from this pilot study that pirfenidone potentially offers a novel therapeutic modality for the management of rheumatoid arthritis with little or no adverse effects unlike steroidal and non-steroidal anti-inflammatory drugs which are frequently used for this chronic debilitating disease.

Pirfenidone suppressed the development of glomerulosclerosis in the FGS/Kist mouse.

Pirfenidone (PFD) is a newly developed anti-fibrotic agent. We evaluated the effect of PFD for the prevention of renal fibrosis using a spontaneous progressive glomerulosclerosis animal model, FGS/Kist mice. Male and female FGS/Kist mice were fed a diet containing 0.5% PFD or the same control diet (CD) without PFD, for 1, 2, or 3-month periods. Body weight was monitored for the general effect of PFD on the mice. Proteinuria and glomerular filtration rate (GFR) were evaluated for renal function. The sclerosis index was examined for the morphological changes. There were no significant changes in body weight between the PFD and control groups in both sexes. Proteinuria levels were low in all the PFD groups compared to the corresponding CD groups. The sclerosis scores were also reduced in both sexes of the 3-month PFD groups (p<0.05), and glomerular filtration rates were increased in both sexes of the 3-month PFD groups compared to the CD groups. The treatment of PFD for 1 or 2-month periods did not have statistic significances but the treatment for 3 months had statistic significances in sclerosis and GFR compared to CD groups. These results suggested that long-term administration of PFD suppressed the progression of glomerulosclerosis and improved renal function of the FGS/Kist mice.

Pirfenidone inhibits early myointimal proliferation but has no effect on late lesion size in rats.

AIMS: intimal hyperplasia is mediated by smooth muscle cell proliferation, migration and deposition of extracellular matrix. The anti-fibrotic agent pirfenidone has been shown to inhibit pro-fibrotic growth factors in non-vascular inflammatory models. This study investigated the effect of the novel anti-fibrotic agent pirfenidone on the development of neointima. METHODS: male Sprague-Dawley rats received either standard diet or diet supplemented with pirfenidone (250, 500, 1000 mg/kg/day). Animals underwent left common carotid balloon angioplasty and were explanted at 4, 8, 14 and 28 days and analysed for intimal thickening, pro-fibrotic gene expression, extracellular matrix deposition and metalloproteinase activity. RESULTS: neointimal thickness was significantly reduced in a dose-dependent manner at 14 days; pirfenidone 250 mg/kg (p<0.005), pirfenidone 500 mg/kg (p<0.001), pirfenidone 1 g/kg ( p<0.001). There were no significant differences in intimal thickening at 28 days. Expression of MMP-2, MMP-9, TIMP-1, collagen III and TGF-beta were all significantly inhibited at 14 days. Both collagen III expression and ECM deposition were reduced at 28 days ( p<0.05 and <0.002 respectively). CONCLUSION: pirfenidone reduces expression of MMPs governing smooth muscle cell proliferation and migration (MMP-2 and 9), and genes favouring ECM accumulation (TIMP-1 and collagen III). This study shows that inhibition of MMP activity is not sufficient to inhibit late lesion size.

Pirfenidone for chronic progressive multiple sclerosis.

Current treatment of secondary progressive multiple sclerosis is unsatisfactory in stabilizing or reversing the disabilities associated with the disease. Pirfenidone is a new non-peptide drug which has been shown in vitro and in vivo to decrease synthesis of Tumor Necrosis Factor-alpha (TNF-alpha) and block receptors for TNF-alpha. Since TNF-alpha seems to be a key cytokine in demyelination, a pilot study of oral pirfenidone was undertaken in an open-label baseline vs treatment protocol over a 2-year period in 20 patients. Fourteen (14120) patients (70%) remained in the study for 2 years. Three (3/20) patients dropped out early because of gastrointestinal adverse reactions, and another three patients dropped out for personal reasons after 1 year (not because of adverse reactions). The remaining patients did not manifest any other drug-related adverse reactions and complications. Improvement or stabilization occurred in most patients at about 3 months, and it was sustained at 6, 12 and 24 months as evaluated by both primary and secondary outcome measures. Magnetic resonance imaging foiled to reveal any new lesions. Thus, pirfenidone appears to offer protection against the usual slow progression of the disease. Most patients experienced a distinct decrease in their neurological disability. These findings indicate that an extensive multi-center double blind and placebo controlled trial is warranted.

A phase II trial of pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone), a novel anti-fibrosing agent, in myelofibrosis with myeloid metaplasia.

The anti-fibrotic and cytokine modulatory properties of pirfenidone suggest its usefulness in the treatment of myelofibrosis with myeloid metaplasia (MMM). In a prospective study, 28 patients with MMM were treated with oral pirfenidone. Twelve patients completed 1 year of therapy; 13 were withdrawn because of disease progression and three because of drug intolerance. Only one patient experienced a clinically relevant benefit with respect to anaemia and splenomegaly. The overall lack of clinical benefit correlated with no significant improvement in the bone marrow morphological features of the disease. We conclude that pirfenidone has no significant clinical or biological activity in MMM.

Reversal of cardiac and renal fibrosis by pirfenidone and spironolactone in streptozotocin-diabetic rats.

Fibrosis leads to chronic impairment of cardiac and renal function and thus reversal of existing fibrosis may improve function and survival. This project has determined whether pirfenidone, a new antifibrotic compound, and spironolactone, an aldosterone antagonist, reverse both deposition of the major extracellular matrix proteins, collagen and fibronectin, and functional changes in the streptozotocin(STZ)-diabetic rat. Streptozotocin (65 mg kg(-1) i.v.)-treated rats given pirfenidone (5-methyl-1-phenyl-2-[1H]-pyridone; approximately 200 mg kg(-1) day(-1) as 0.2 - 2g 1(-1) drinking water) or spironolactone (50 mg kg(-1) day(-1) s.c.) for 4 weeks starting 4 weeks after STZ showed no attenuation of the increased blood glucose concentrations and increased food and water intakes which characterize diabetes in this model. STZ-treatment increased perivascular and interstitial collagen deposition in the left ventricle and kidney, and surrounding the aorta. Cardiac, renal and plasma fibronectin concentrations increased in STZ-diabetic rats. Passive diastolic stiffness increased in isolated hearts from STZ-diabetic rats. Both pirfenidone and spironolactone treatment attenuated these increases without normalizing the decreased +dP/dt(max) of STZ-diabetic hearts. Left ventricular papillary muscles from STZ-treated rats showed decreased maximal positive inotropic responses to noradrenaline, EMD 57033 (calcium sensitizer) and calcium chloride; this was not reversed by pirfenidone or spironolactone treatment. STZ-treatment transiently decreased GFR and urine flow rates in isolated perfused kidneys; pirfenidone but not spironolactone prevented the return to control values. Thus, short-term pirfenidone and spironolactone treatment reversed cardiac and renal fibrosis and attenuated the increased diastolic stiffness without normalizing cardiac contractility or renal function in STZ-diabetic rats.

Low frequency of E-cadherin alterations in familial breast cancer.

In order to explore the possible role of E-cadherin in familial cancer, 19 familial breast cancer patients, whose tumours demonstrated loss of heterozygosity (LOH) at the E-cadherin locus, were screened for germline mutations. No pathogenic germline alterations were detected in these individuals. However, a somatic mutation was found (49-2A-->C) in one of the tumours. This tumour showed a pattern of both ductal and lobular histology. Another 10 families with cases of breast, gastric and colon cancer were also screened for germline mutations, and no mutations were found. A missense mutation in exon 12 of E-cadherin (1774G-->A; Ala592Thr) was previously found in one family with diffuse gastric cancer, and colon and breast cancer. An allelic association study was performed to determine whether the Ala592Thr alteration predisposes to breast cancer. In total, we studied 484 familial breast cancer patients, 614 sporadic breast cancer patients and 497 control individuals. The frequencies of this alteration were similar in these groups. However, a correlation between the Ala592Thr alteration and ductal comedo-type tumour was seen. These results, together with previously reported studies, indicate that germline mutations and, more commonly, somatic mutations in E-cadherin may have an influence on the behaviour of the tumours, rather than predispose to breast cancer.

Pirfenidone reduces in vitro rat renal fibroblast activation and mitogenesis.

BACKGROUND: Fibroblasts have been universally recognised in tubulointerstitial injury, where their presence has been shown to be a marker of disease progression. Recently, pirfenidone (PF) has been shown to both ameliorate progressive fibrosis and reduce established scarring after ureteric obstruction (UUO) in the rat, suggesting that it is a novel anti-fibrotic agent. The objective of this study was therefore to determine if these effects include down-regulation of fibroblast function. METHODS: Cortical fibroblasts were obtained from outgrowth cultures of renal tissue isolated from kidneys 3 days after UUO and constituted 100% of cells studied. Functional studies examined the effects of 20 and 200 microg/ml PF on basal serum stimulated activity. Activation was examined by western blotting for alpha smooth muscle actin (alphaSMA) and connective tissue growth factor (CTGF). Cell proliferation, collagenase activity and collagen production were determined from kinetic studies, zymography for MMP2 and [3H] proline incorporation in collagenous proteins respectively. RESULTS: Proliferation, as measured by [3H] thymidine incorporation, was reduced in dose dependent manner by 20 and 200 microg/ml PF (p<0.05; 200 vs 0 microg/ml). Likewise, 200 microg/ml PF reduced cell population growth over 5 days of culture (p<0.05 vs 0 microg/ml). PF (200 microg/ml) decreased alphaSMA and CTGF protein expression to 66+/-13 and 37+/-26% of basal levels respectively (both p<0.05 vs 0 microg/ml). Synthesis of collagen was unaffected by PF. Maximal dose of PF produced a modest reduction in MMP2 lytic activity (p=0.05). Effects of PF were independent of cell toxicity. CONCLUSIONS: Down-regulation of renal fibroblast activation and proliferation are specific actions of PF.

Effects of pirfenidone on the generation of reactive oxygen species in vitro.

Pirfenidone is a newly developed antifibrotic drug that has been reported to retard the progression of pulmonary fibrosis induced by bleomycin and cyclophosphamide in animal models of lung fibrosis. The present in vitro studies using noncellular and cellular systems evaluated the antioxidant and cytotoxic properties of this drug. The Fenton reaction [Fe(II) + H2O2 --> Fe(III) + *OH + OH-] and the xanthine/xanthine oxidase system were used as sources of hydroxyl (*OH) and superoxide anion (O2*-) radicals, respectively. Electron spin resonance spin trapping was used for free radical detection and measurement. The reaction rate of pirfenidone with *OH was found to be 1.63 x 10(10) M(-1) s(-1), which is comparable to several well-established antioxidants, such as ascorbate, glutathione, cysteine, azide, and lipoic acid. Compared to *OH radicals, the O2*- scavenging was less efficient 42.36 M(-1) s(-1) with pirfenidone. Pirfenidone was also effective in inhibiting zymosan-stimulated chemiluminescence. In a noncellular model of lipid peroxidation, pirfenidone inhibited crystalline silica-induced lipid peroxidation. The inhibition of crystalline silica-induced cytotoxic reactions and lipid peroxidation combined with the efficient antioxidant properties of pirfenidone indicate that this agent may express its antifibrotic effects partly through its ability to scavenge reactive oxygen species.

Involution of keloid implants in athymic mice treated with pirfenidone or with triamcinolone.

The experimental drug pirfenidone (PFD) has been evaluated as an inhibitor of keloid proliferation and compared with triamcinolone (TAC) injections by studying the involution of active human keloid implants in athymic nude mice (nu-nu). PFD was fed to mice with keloid implants at a level of 2.75 mg/g of feed. At this level PFD had no adverse effect on the body weights of the mice. Implant weights in both PFD-fed and control mice decreased with time. The weights of the implants from the PFD group were significantly lower than those of the control implants at 60 and 90 days after implantation. Consequently PFD may cause an increased degradation and absorption of keloid tissue. The implants from the PFD mice were not significantly different histologically from the implants of the mice with corresponding implants. The chondroitin-4-sulfate (C4S) levels of the implants from PFD-fed mice were not significantly different from those of the implants from control mice. Therefore the mechanism of action of PFD apparently is not mediated by an effect on C4S metabolism. In contrast, the injections of TAC at a level that caused temporary body weight loss in the mice resulted in significant decreases in both hyaluronic acid (HA) and C4S in the keloid implants. Histologically, fibroblasts disappeared from the implants treated with TAC by 20 days after injection. At 30 days after TAC injection, HA and C4S were not detected by electrophoresis in keloid implants; only dermatan sulfate appeared to be present.

Pirfenidone induces intercellular adhesion molecule-1 (ICAM-1) down-regulation on cultured human synovial fibroblasts.

Pirfenidone has been shown to modify some cytokine regulatory actions and inhibit fibroblast biochemical reactions resulting in inhibition of proliferation and collagen matrix synthesis by fibroblast. We have investigated the effect of pirfenidone on the expression of cell adhesion molecules. The synovial fibroblasts were treated with IL-1alpha in the presence or absence of pirfenidone (range 0-1000 microM), and assayed for the expression of adhesion molecules such as ICAM-1 and endothelial-leucocyte adhesion molecule-1 (E-selectin) by cell ELISA. Pirfenidone significantly down-regulated the expression of ICAM-1 on cultured synovial fibroblasts in a dose-dependent manner. In contrast, expression of E-selectin was not affected. Furthermore, we examined whether pirfenidone affects the cellular binding between cultured lymphocytes and IL-1alpha-stimulated synovial fibroblasts by in vitro binding assay and found their mutual binding was significantly suppressed in a dose-dependent manner by pirfenidone. It is speculated that down-regulation of ICAM-1 might be one of the novel mechanisms of action of pirfenidone. These data indicate a novel mechanism of action for pirfenidone to reduce the activation of synovial fibroblasts.

Pirfenidone improves renal function and fibrosis in the post-obstructed kidney.

BACKGROUND: Pirfenidone (PFD) is a novel anti-fibrotic agent that can prevent and even reverse extracellular matrix accumulation in several organs, as shown by experimental and clinical studies. Unilateral ureteral obstruction (UUO) is a well-characterized model of experimental renal disease culminating in tubulointerstitial fibrosis. METHODS: UUO or sham-operated rats were administered PFD (500 mg/kg/day) in their food for 21 days to examine the effect on collagen production. The renal function was measured in the kidney after release of obstruction which had been maintained for one week to examine the effects of PFD on restoration after renal dysfunction. RESULTS: The collagen content detected by hydroxyproline progressively increased in kidney with UUO for 21 days. These increases were significantly suppressed by administration of PFD. PFD had no effect on collagen production in sham-operated rats. Expression of mRNA for type IV and I collagen and matrix metalloproteinase-2 in the cortex increased with UUO, but was inhibited by PFD treatment. The levels of cortical transforming growth factor-beta (TGF-beta) mRNA progressively rose with UUO for 21 days, but this increase also could be suppressed by PFD. Inulin clearance of the obstructed kidney was markedly depressed and remained low at five weeks after release. A progressive increase in hydroxyproline content was also observed in the post-obstructed kidney despite the release of obstruction. Administration of PFD following the release not only attenuated collagen accumulation, but also induced recovery of the impaired renal function. CONCLUSIONS: These results demonstrate that PFD can attenuate both renal fibrosis and renal damage in this model, and suggest that PFD can be clinically useful for preventing progressive, irreversible renal failure.