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Biomedical subjects

P Harper

Publications and source records attributed to P Harper.

At least 19 recordsLinked to original sources

A randomized phase III study comparing dacarbazine, BCNU, cisplatin and tamoxifen with dacarbazine and interferon in advanced melanoma.

The purpose of this study was to compare the response rate, overall and 1-year survival in patients with advanced melanoma treated with a standard therapy, dacarbazine and interferon-alpha (DTIC/IFN), or combination chemotherapy, consisting of dacarbazine, BCNU, cisplatin and tamoxifen (DBCT). Treatment toxicity and time spent in hospital were secondary end points. One hundred and five patients (of whom 100 were eligible) were randomized to receive either DTIC/IFN or DBCT. The trial was designed to detect a 25% absolute difference in response rate or in 1-year survival with 80% power. There was no significant difference in response rate: this was 17.3% with DTIC/IFN and 26.4% with DBCT. Median overall survival was similar at 199 and 202 days respectively. One-year survival rate favoured standard treatment (30.6 vs 22.6%), but did not differ significantly between arms. DBCT was associated with significantly greater haematological toxicity, and a greater need for time spent in hospital (5.75 days/treatment cycle vs 2.29 with dacarbazine and interferon). DBCT combination therapy cannot be recommended as standard treatment for advanced melanoma. Dacarbazine remains the standard chemotherapy for this condition.

Adult

A model protocol evaluating the introduction of genetic assessment for women with a family history of breast cancer.

Randomised controlled trials allow comparisons to be made between different models of service delivery, but have not been used in the field of clinical genetics. With the advent of clinical governance, the evidence provided by such trials will be increasingly important in informing and shaping clinical genetics practice. The TRACE project (Trial of genetic assessment in breast cancer) is a randomised controlled trial of genetic assessment for women who are at increased risk of breast cancer because of their family history. The absence of cancer genetics service provision in Wales before this study gave a window of opportunity in which this important trial could be conducted. The present paper describes how TRACE will provide crucial evidence regarding the psychosocial as well as resource implications of adding individualised genetic assessment, genetic counselling, and (where appropriate) gene testing to typical advice and surveillance from a hospital breast clinic. In addition, it is anticipated that TRACE will represent a model for future trials of service delivery in the increasing number of complex genetic disorders where evidence on the economic implications of screening and management is currently limited.

Adult

Why do women attend familial breast cancer clinics?

The increasing demand for genetic assessment for familial breast cancer has necessitated the development of cancer genetics services. However, little is known about the factors motivating the client population likely to approach these services. A cross sectional questionnaire survey of 1000 women with a family history of breast cancer was conducted to identify self-reported reasons for attending a familial breast cancer clinic and possible differences in the characteristics of women who were attending for diverse reasons. Before attendance at clinic, 833 women completed a baseline questionnaire (83% response rate). Women who gave personal risk (n=188), awareness of a family history (n=120), risk to family members (n=84), reassurance (n=69), genetic testing (n=65), breast screening (n=46), or prevention (n=39) as their main reason for attending were compared on demographic and medical variables, and on psychological variables including general anxiety, cancer worry, perceived risk, and attitudes towards prophylactic surgery and genetic testing. Important differences in the psychological characteristics of these groups were found, which were unrelated to reported family history. In particular, women who primarily wanted genetic testing felt extremely vulnerable to developing breast cancer, were more likely to be considering prophylactic surgery, and perceived fewer limitations of testing. Those who primarily wanted reassurance were highly anxious about the disease. We recommend that cancer genetics services take into consideration the informational and psychological needs and concerns of their client group.

Ambulatory Care Facilities

Treatment of nondysgerminomatous ovarian germ cell tumors: an analysis of 69 cases.

BACKGROUND: Combination chemotherapy has dramatically improved the prognosis of patients with nondysgerminomatous ovarian germ cell tumors (NDOGCT). However, guidelines are needed for the identification of patients at risk of relapse. METHODS: The authors performed a retrospective analysis of women with NDOGCT managed during the period 1970-1994 at the Royal Marsden Hospital and other hospitals of the London Gynaecological Oncology Group. RESULTS: Sixty-nine women were included; their median follow-up was 5.7 years (minimum, 12 months). The median age was 21 years (range, 4-44 years), with a histology of immature teratoma (IT) for 17 patients, endodermal sinus tumor (EST) for 20 patients, and mixed tumors for 32 patients. Thirty-five patients (51%) had Stage I disease. Nine patients with Stage I tumors were observed without further therapy (six with IT and three with mixed tumors), and one relapsed. Seven patients received non-platinum-based chemotherapy, and four relapsed. A total of 52 patients were treated with platinum-based chemotherapy, with relapse free and overall survival rates of 87% (95% confidence interval [CI], 73-93%) and 84% (95% CI, 70-91%), respectively. Of these patients, relapse was seen in 0 of 9 IT patients, 1 of 25 patients with mixed tumors, and 6 of 18 EST patients. With alpha-fetoprotein (AFP) > 1000 kU/L, relapse was seen in 6 of 18 patients compared with 1 of 33 relapses with lower AFP levels. In multivariate analysis, including all patients who received chemotherapy, AFP >1000 kU/L (P = 0.001) and non-platinum-based chemotherapy (P = 0.005) were associated with relapse. When only patients given platinum-based treatment were considered, EST histology (P = 0.003) and AFP >1000 kU/L (P = 0.003) were associated with relapse in univariate analysis; however, these factors were linked. No malignant tumor was found at second-look surgery performed on 24 patients. Of 26 women assessable for fertility, 24 subsequently recommenced regular menstrual function, and 11 patients had pregnancies. CONCLUSIONS: Platinum-based chemotherapy has been confirmed to be effective in the management of patients with NDOGCT. Relapses were principally seen among patients with AFP >1000 kU/L or pure EST histology. Efforts to improve outcome need to focus on patients with EST, whereas less intensive management strategies may be appropriate for some patients with IT.

Adolescent

Self-expanding metallic stents in the management of pyloric dysfunction after gastric pull-up operations.

The purpose of this paper is to report the use and benefits of self-expanding metallic stents employed in pyloric dysfunction. Four patients treated with oesophagectomy and gastric pull-up for oesophageal carcinoma failed to respond to balloon dilatation for pyloric dysfunction. Three of the patients were thought to have residual tumour at sites remote from the pylorus prior to stenting, but the fourth, who had undergone surgery 8 years previously, was thought to be cured. All were treated with self-expanding metallic stents. All four patients responded well with resolution of their symptoms. Over a mean follow-up of 6 months there has been no recurrence of symptoms. Stent insertion represents a potentially valuable method of treatment in patients with post-surgical pyloric dysfunction in whom simple balloon dilatation has failed.

Aged

Intergroup collaboration in ovarian cancer: a giant step forward.

The rather slow evolution of so-called "optimal chemotherapy" for ovarian cancer is the result of suboptimal randomised clinical trials, not having the statistical power to identify truly superior regimens, and of the lack of systematic comparisons of new agents with relevant control arms. There is little doubt that we need international collaboration to move the field forward in a timely and coherent manner. European and transatlantic collaboration represents the beginning of the process and point to the success that can await us if the drive to work together remains strong. A similar organisation as for breast cancer (Breast International Group, BIG) needs to be established for ovarian cancer.

Clinical Trials as Topic

Long-term survival after epirubicin, cisplatin and fluorouracil for gastric cancer: results of a randomized trial.

We report the final results of a prospectively randomized study that compared the combination of epirubicin, cisplatin and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin and methotrexate (FAMTX) in previously untreated patients with advanced oesophagogastric cancer. Between 1992 and 1995, 274 patients with adenocarcinoma or undifferentiated carcinoma were randomized from eight oncology centres in the UK and analysed for response and survival. The overall response rate was 46% (95% confidence interval (CI), 37-55%) with ECF, and 21% (95% CI, 13-28%) with FAMTX (P = 0.00003). The median survival was 8.7 months with ECF and 6.1 months with FAMTX (P = 0.0005). The 2-year survival rates were 14% (95% CI, 8-20%) for the ECF arm, and 5% (95% CI, 2-10%) for the FAMTX arm (P = 0.03). Histologically complete surgical resection following chemotherapy was achieved in ten patients in the ECF arm (three pathological complete responses to chemotherapy) and three patients in the FAMTX arm (no pathological complete responses). The ECF regimen resulted in a response and survival advantage compared with FAMTX chemotherapy. The probability of long-term survival following surgical resection of residual disease is increased by this treatment. The high response rates seen with ECF support its use in the neoadjuvant setting.

Antineoplastic Combined Chemotherapy Protocols

A novel mutation of delta-aminolaevulinate dehydratase in a healthy child with 12% erythrocyte enzyme activity.

Cloning, expression and phenotype studies of the defective gene for delta-aminolaevulinate dehydratase (ALAD) in a family with an asymptomatic girl who had ALAD deficiency were carried out. The proband was identified by neonatal ALAD screening, and had erythrocyte ALAD activity at 12% of the normal control. She was heterozygous for ALAD deficiency, which was inherited from her father. Nucleotide sequence analysis of the cloned ALAD cDNA revealed C36 to G and T168 to C mutations on the same allele. The former mutation resulted in F12L substitution, whereas the latter was a silent mutation. All family members who had decreased ALAD activity had the same mutation. Expression of the mutant ALAD cDNA in Chinese hamster ovary cells produced an ALAD protein without significant enzyme activity. Additionally, the mutant ALAD cDNA which encodes F12L substitution produced an aberrant migration pattern in polyacrylamide gel electrophoresis under denaturing conditions. This finding probably reflects an abnormal folding of the F12L protein, since the mutation occurred in the alpha1 helix of the N-terminal arm of the enzyme, which is involved in the extensive quaternary interactions among the subunits. This is also the first report of ALAD gene mutation in an asymptomatic subject.

DNA, Complementary

Vinorelbine (Navelbine) in the treatment of non-small-cell lung cancer: studies with single-agent therapy and in combination with cisplatin.

Initial studies of vinorelbine (Navelbine) given as a single agent to patients with operable non-small-cell lung cancer (NSCLC) showed that overall response rates of the order of 30% could be obtained with a schedule of 30 mg/m2 given weekly. Although such high levels of response have seldom been obtained when vinorelbine is given alone in one arm of a comparative study, the level of activity is clearly worthwhile and represents a significant improvement over supportive care. Combination therapy with cisplatin has been highly successful, establishing Vinorelbine as a safe well-tolerated agent which provides considerable activity, and experience from large phase III studies suggests that the combination of vinorelbine and cisplatin could represent a reference schedule against which other therapy should be compared.

Antineoplastic Agents, Phytogenic

Vinorelbine (navelbine) in the treatment of non-small-cell lung cancer: recent developments in combination chemotherapy and radiotherapy.

The investigation of the activity of vinorelbine in non-small-cell lung cancer (NSCLC) has continued beyond the initial studies which established its single agent activity and defined the combination of vinorelbine and cisplatin as one of the standard treatments for inoperable NSCLC. Alternative partners to cisplatin have been evaluated in combination therapy with vinorelbine with promising results emerging from combinations with carboplatin, ifosfamide, mitomycin C and gemcitabine. Three drug combinations such as vinorelbine, cisplatin and ifosfamide can clearly produce high response rates in patients with good performance status at the time of treatment. The ability of vinorelbine to contribute to disease reduction either alone or in combination with other cytotoxic drugs has made it possible to consider its use in neo-adjuvant therapy, while the synergistic action of vinorelbine with radiotherapy has encouraged the use of sequential or concomitant chemoradiotherapy producing high response rates after completion of both modalities. The possible role of post-operative adjuvant treatment with Vinorelbine either alone or in combination with cisplatin is being assessed in a prospective trial.

Antineoplastic Combined Chemotherapy Protocols

Which 5-fluorouracil regimen?--the great debate.

5-Fluorouracil (5-FU) has been available for over 40 years and has been used in a wide variety of different regimens for the treatment of advanced colorectal cancer, a malignancy with a poor prognosis that is common in industrialized countries. However, despite numerous clinical trials in which 5-FU has been used alone and in combination with a variety of modulating agents [chiefly leucovorin (LV)], and has been administered by bolus injection and i.v. infusion, the optimal regimen for the management of advanced colorectal cancer remains unclear, and there are notable national and international variations in clinical practice. The toxicity of 5-FU also remains an obstacle to the achievement of overall clinical benefit in many patients. The introduction of novel chemotherapeutic agents may make it necessary to reassess the place of 5-FU in the treatment of advanced colorectal cancer. This article debates these issues with a review of clinical trials of 5-FU, and concludes that the future lies in the utilization of novel and established agents in combinations that may significantly improve outcomes, rather than in continuing experimentation with various schedules of 5-FU and LV.

Antimetabolites, Antineoplastic

Myotonic dystrophy: the correlation of (CTG) repeat length in leucocytes with age at onset is significant only for patients with small expansions.

Myotonic dystrophy (DM) was the first of a group of diseases to be identified for which the genetic basis is the expansion of a triplet repeat. Myotonic dystrophy also exhibits anticipation, in which the disease worsens through successive generations. These two features have led many groups to analyse whether a significant negative correlation between triplet repeat length and severity of disease exists. However, the recent molecular finding that two distinct subsets of classically affected DM patients exist, those who export expansion derived DMPK RNA and those who do not, led us to question whether combining data from these two sets of patients is statistically valid. We found that although patients with small expansions showed a significant correlation between age at onset and triplet repeat length, those with larger expansions did not. The theoretical triplet repeat size, which separated the two groups, was also deduced.

Age of Onset

[Porphyria cutanea tarda is the most common type of porphyria. Medical control is a team work].

Porphyria cutanea tarda (PCT) is probably the most common of the porphyrias. The development of skin fragility and blisters are the symptoms that generally bring the patient to the notice of the dermatologist. During the past decade the disease has been recognised as being of heterogeneous aetiology, and a pathogenetic classification has been proposed. The significance of subtyping for the choice of management strategy is currently appreciated, as is the need of close monitoring owing to the risk of the common PCT-associated liver conditions. Preferably the PCT patient should be managed by a dermatologist and a hepatologist working in concert and supported by a specialised porphyria laboratory. The use of a structured management protocol should be considered.

Diagnosis, Differential

[Prevention of acute intermittent porphyria is the best solution. Most important are early diagnosis and counseling].

Recent mapping of acute intermittent porphyria (AIP) in Sweden has confirmed its very high prevalence in northern districts, though about fifty per cent of the gene carriers are to be found in the central and southern parts of the country. More than eighteen different AIP mutations are currently recognised in the Swedish kindreds. One mutations, evidently originating in northern Sweden, is predominant. As AIP is a pharmacogenetic disease, more than 200 substances being currently known to precipitate the neuropsychiatric symptoms, the greatest care is required in prescribing drugs to carriers of genetic predisposition to the disease. Guidelines are provided in the booklet. Drugs contraindicated in acute porphyria (Läkemedel farliga vid akut porfyri), jointly issued by the Swedish Porphyria Association and the Corporation of Swedish Pharmacists (Apoteksbolaget). Where doubt exists, specialists should be consulted since there are a number of factors that may contribute to an adverse reaction. Early diagnosis, preferably before puberty, and counselling are the cornerstones of management, and genetic analysis the diagnostic tool of choice, applicable in most families. In the symptomatic phase, glucose or haem arginate is effective in reversing the metabolic processes responsible for the exacerbation. Recently, the hepatic and late renal manifestations of the disease have been recognised, and early detection of the associated conditions is recommended. This includes monitoring for paraneoplastic prodromes of hepatocellular cancer.

Genetic Counseling

[Risk of liver failure in erythropoietic protoporphyria. Be alert for sings of cholestatic development!].

Erythropoietic protoporphyria (EPP) presents clinically as a painful skin reaction to sun-light exposure. The profoundly disabling psychosocial consequences of the disease often go unnoticed by the physician, and the need to monitor the patient for hepatic complications is not generally recognised. The article describes the clinical and biochemical course in a 51-year-old man with EPP, who within a few days developed signs of acute hepatic failure. The case emphasises the importance of a well designed monitoring programme that allows close evaluation of the patient's current porphyrin metabolism, and indicates what measures should be considered.

Cholestasis, Intrahepatic

[Porphyria--a metabolic mine field].

The porphyrias, uncommon conditions often eluding diagnosis, extremely susceptible to inappropriate treatment and associated with severe late manifestations, are representative of the small groups of scarce and complex diseases that are difficult to manage without specialised resources. A network of offices with diagnostic and consultative support from a national specialist centre is probably the most cost effective way of meeting the patients' demands in terms of highly specialised medical experience coupled with close contact and continuity This approach, adopted by the Swedish Porphyria Centre, is based on well structured and regularly updated programmes for the management of porphyria patients.

Counseling

Genetic variation in the 3' untranslated region of the neurofibromatosis 1 gene: application to unequal allelic expression.

Neurofibromatosis type 1 (NF1) is a common genetic disorder caused by inactivation of neurofibromin, a protein capable of modulating signal transduction by activating Ras-GTPase activity. We have used cDNA cloning and Northern blot analysis to confirm the NF1 gene produces alternatively polyadenylated mRNAs with 3' untranslated regions (3' UTR) that show striking evolutionary conservation. Scanning of the 3'UTRs for genetic variation revealed three common sequence polymorphisms (> 30% heterozygosity), one less informative polymorphism (approximately 5% heterozygosity) and one rare variant (1/144 chromosomes). These differences were used to examine relative levels of expression of normal and mutant NF1 alleles in lymphoblast cell lines and in one case, autopsy tissue, from patients with NF1. Unequal allelic expression (up to 4-fold) was observed in a subset of both sporadic and familial NF1 cases. Where linkage phase could be determined, the allele segregating with the disorder displayed a relative reduction in expression. However, the magnitude of this effect was variable suggesting the operation of additional, non-genetic factors in determining the degree of relative expression of the mutant allele.

3' Untranslated Regions

BRCA1 and BRCA2 in breast cancer families from Wales: moderate mutation frequency and two recurrent mutations in BRCA1.

Mutations in the BRCA1/BRCA2 genes account for varying proportions of breast cancer families studied, and demonstrate considerable variation in mutational spectra coincident with ethnic and geographical diversity. We have screened for mutations in 17 families from Wales with two or more cases of breast cancer under age 50 and/or ovarian cancer. Eight out of 17 (47%) families had demonstrable mutations. Six out of 17 (35%) carried BRCA1 mutations and 2 out of 17 (12%) carried BRCA2 mutations. Two recurrent mutations in BRCA1 were identified, which appear to represent founder mutations in this population. These data support the existence of additional breast and ovarian cancer susceptibility genes.

Adult