Practice guideline for the role of combination chemotherapy in the initial management of limited-stage small-cell lung cancer

An evidence-based practice guideline was developed to identify the optimal combination chemotherapy regimen, schedule of administration, and duration of therapy for the first-line treatment of adults with limited-stage small-cell lung cancer. The guideline is based on a systematic search and review of literature published between 1985 and December 2002. Three reviewers selected studies for inclusion in the guideline according to pre-defined criteria. Fifty randomized controlled trials, five in abstract form, were included in the review, and feedback on a draft version of the guideline was obtained from medical oncologists in the province of Ontario, Canada. The most commonly used regimens in clinical trials are cyclophosphamide-doxorubicin(Adriamycin)-vincristine, and etoposide-cisplatin. No combination chemotherapeutic regimen has been conclusively shown to be superior to either of these regimens. Most studies comparing chemoradiation regimens used sequential rather than concurrent thoracic radiotherapy. When treating for cure with chemoradiation, there is evidence from one randomized controlled trial to support the use of etoposide-cisplatin over an anthracycline-containing regimen. There is conflicting evidence concerning a survival advantage for a regimen that alternates cyclophosphamide-doxorubicin-vincristine with etoposide-cisplatin compared with either regimen alone. If bolus etoposide-cisplatin is the treatment of choice, evidence from one randomized trial suggests that the optimal sequence of administration is cisplatin followed by etoposide. The use of maintenance chemotherapy is not indicated. There is insufficient evidence to support the routine use of dose-intensive regimens outside a clinical trial, to determine the optimal duration of chemotherapy, or to support the routine substitution of carboplatin for cisplatin in combination chemotherapy regimens in this patient population.

RECOMMENDATIONS

Etoposide-cisplatin is the preferred chemotherapy regimen for patients with limited-stage small-cell lung cancer when concurrent thoracic radiotherapy is used. It is reasonable to offer the alternation of etoposide-cisplatin with cyclophosphamide-doxorubicin-vincristine, provided the administration of radiotherapy concurrent with an anthracycline is avoided.

Measuring women's preferences for breast cancer treatments and BRCA1/BRCA2 testing

In establishing decision models in the treatment and prevention of breast cancer, it is important to evaluate patients' preferences for such interventions. The objectives of the present study were: (i) to characterize women's preferences for breast cancer treatments and BRCA1/BRCA2 testing, using the rating scale and standard gamble techniques; and (ii) to identify factors associated with these quality of life indices. Data were collected from women with breast cancer (n = 60), high-risk relatives of women with breast cancer (n = 58), and women in the general population (n = 51). Regardless of group membership, participants favoured treatment and prevention options that involved minimal physical invasiveness. Women with breast cancer rated lumpectomy and radiation treatment more highly than high-risk relatives and women in the general population. Preferences did not differ according to participants' intentions to undergo BRCA testing. Age was the only demographic variable associated with health state preferences. These findings hold implications for the application of patient preferences to clinical decision making.

Canadian oncologists and clinical practice guidelines: a national survey of attitudes and reported use. Provincial Lung Disease Site Group of Cancer Care Ontario

PURPOSE

To determine (1) Canadian oncologists' attitudes toward practice guidelines, (2) oncologists' self-reported use of practice guidelines and, (3) physicians' characteristics and attitudes associated with self-reported use of practice guidelines.

PARTICIPANTS AND METHODS

A cross-sectional, self-administered postal survey was administered to Canadian oncologists. Main outcome measures were level of agreement with 8 descriptive statements about guidelines, score on the attitudinal scale of the guideline of Tunis et al., and physicians' stated use of guideline. chi(2) and logistic regression procedures were used to explore the relationship between physician characteristics and use of guidelines.

RESULTS

Over 80% of respondents agreed that they were good educational tools, convenient sources of advice, intended to improve quality of care; over 40% agreed that they were unbiased syntheses of expert opinion. Conversely, 42, 26, 20 and 16% felt they were intended to cut costs, were oversimplified cookbook medicine, were too rigid to apply to individual patients, and a challenge to physicians' authority, respectively. Forty-one percent reported using practice guidelines routinely or most of the time. Use was associated with positive attitudes about guidelines, receiving medical school training abroad and being a radiation oncologist.

CONCLUSION

Canadian oncologists were quite positive about practice guidelines and reported using them frequently. Our results suggest that use of guidelines by oncologists may be related to attitudes about guidelines in general, specialty within oncology and country of medical school training.

Aggressive behavior in clinically depressed adolescents

OBJECTIVE

To investigate the prevalence and characteristics of aggressive behavior in adolescent inpatients and outpatients with major depressive disorder (MDD). Differences between males and females in prevalence and type of aggression, and level of parent-child agreement in report of aggression, were analyzed.

METHOD

Participants were 74 adolescents with MDD, aged 13 to 17 years. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to identify MDD. Adolescents' aggressive behavior was assessed using an adapted version of the Brown-Goodwin Assessment for Lifetime History of Aggression; the Measure of Aggression, Violence, and Rage in Children; and the Buss-Durkee Hostility Inventory-Adapted Version.

RESULTS

Results indicate high levels of aggressive behavior in adolescents with MDD. Amount and type of aggression did not differ by gender. Results indicate poor correspondence between parent and adolescent reports of aggression, which was most marked for females.

CONCLUSIONS

Aggressive behaviors are highly prevalent in depressed youths, with similar types and levels evident in males and females. Parents tend to under-report and may not be cognizant of aggressive behavior that occurs outside the home, particularly for females.

Integrating play therapy in the treatment of children with obsessive-compulsive disorder

While behavioral and psychopharmacological approaches are the most effective interventions for treating obsessive-compulsive disorder (OCD), psychodynamically oriented play therapy can enhance the treatment of children with this disorder. Play therapy techniques are useful in addressing treatment resistance, feelings of shame around OCD symptoms, negative self-concept, and issues of psychosocial adjustment. A case study illustrates this integrated approach to treatment.

Psychological and social determinants of women's decisions to undergo genetic counseling and testing for breast cancer

This study examined the demand for breast cancer genetic testing and counseling among Canadian women diagnosed with breast cancer under the age of 50, together with some of the factors predicting both their intentions to be tested and the degree to which they act on their intentions. Participants were 110 women under the age of 50 and comprised of two groups: 1) women diagnosed with breast cancer (BC, n = 60): and 2) an index group of unaffected women from the general population (GP, n = 50). All participants completed a survey that addressed family history of breast and other cancers, demographic variables, knowledge and attitudes about breast cancer, and genetic testing. Members of the BC group were offered genetic counseling and testing for BRCA1 and BRCA2 free of charge. Overall, 60% of participants indicated they would like the test, and 40% either did not want it or were uncertain. Seventy-two percent of women in the BC group wanted to be tested. Of these, only 49% had actually contacted the genetic counselor about testing at follow-up 3-15 months later. Intention to be tested was associated with presence of breast cancer, greater perceived benefits of testing, fewer perceived 'costs' of testing, and higher levels of concern about the risk of relatives developing breast cancer. Actual arranging to meet with the genetic counselor among women in the BC group was associated with fewer perceived costs of having the test. Results suggest a moderate level of interest in gene testing, though intention to be tested may not translate into actual uptake. Women who do choose to have the test may believe the potential 'costs' of using this new genetic technology to be relatively few. This has implications for genetic counselors in terms of providing balanced and complete information to women considering genetic testing for breast cancer susceptibility.

Glycyl-tRNA synthetase from Thermus thermophilus--wide structural divergence with other prokaryotic glycyl-tRNA synthetases and functional inter-relation with prokaryotic and eukaryotic glycylation systems

The tRNA glycylation system is amongst the most complex aminoacylation systems since neither the oligomeric structure of the enzymes nor the discriminator base in tRNAs are conserved in the phylae. To understand better this structural diversity and its functional consequences, the prokaryotic glycylation system from Thermus thermophilus, an extreme thermophile, was investigated and its structural and functional inter-relations with those of other origins analyzed. Alignments of the protein sequence of the dimeric thermophilic glycyl-tRNA synthetase (Gly-tRNA synthetase) derived from its gene with sequences of other dimeric Gly-tRNA synthetases revealed an atypical character of motif 1 in all these class 2 synthetases. Interestingly, the sequence of the prokaryotic thermophilic enzyme resembles eukaryotic and archaebacterial Gly-tRNA synthetases, which are all dimeric, and diverges drastically from the tetrameric enzymes from other prokaryotes. Cross aminoacylations with tRNAs and synthetases of different origins provided information about functional interrelations between the glycylation systems. Efficient glycylations involving partners from T. thermophilus and Escherichia coli showed conservation of the recognition process in prokaryotes despite strong structural variations of the synthetases. However, Gly-tRNA synthetase from T. thermophilus acylates eukaryotic tRNA(Gly) while the charging ability of the E. coli enzyme is restricted to prokaryotic tRNA(Gly). A similar behaviour is found in eukaryotic systems where the restricted species specificity for tRNA glycylation of mammalian Gly-tRNA synthetase contrasts with the relaxed specificity of the yeast enzyme. The consensus sequence of the tRNAs charged by the various Gly-tRNA synthetases reveals conservation of only G1-C72 in the acceptor arm, C35 and C36 in the anticodon, and the (G10-Y25)-G45 triplet involved in tRNA folding. Conservation of these nucleotides indicates their key role in glycylation and suggests that they were part of the ancestral glycine identity set. These features are discussed in the context of the phylogenic connections between prokaryotes, eukaryotes, and archaebacteria, and of the particular place of T. thermophilus in this phylogeny.

A role for histamine and substance P in immediate allergic responses in guinea pig airways: characterization of MDL 108,207DA, a dual H1/NK-1 receptor antagonist

BACKGROUND

Histamine is a critical mediator of immediate hypersensitivity reactions. Sensory neuropeptides, such as substance P (SP), may also contribute to acute inflammatory responses. A compound which antagonizes both H1 and NK-1 receptors, such as MDL 108,207DA, may present a significant therapeutic advantage over pure antihistamines.

METHODS

The binding affinity of MDL 108,207DA for H1 and NK-1 receptors was evaluated and its potency of antagonism evaluated in vitro. The in vivo antagonism of SP- or histamine-induced microvascular leakage in guinea pig airways was examined. A role for these mediators in antigen-induced microvascular leakage in ovalbumin-sensitized guinea pig airways was examined using MDL 108,207DA as well as the NK-1-selective antagonist FK888 and the H1-selective antagonist pyrilamine alone or in combination.

RESULTS

The affinity of MDL 108,207DA for H1 and NK-1 receptors is similar to that of receptor-selective antagonists. The compound inhibits both receptors in vitro and in vivo with comparable potencies for each. The efficacy of FK888 in combination with pyrilamine and MDL 108,207DA on antigen-induced microvascular leakage in sensitized guinea pig airways supports a role for both SP and histamine in early allergic responses.

CONCLUSION

The contribution of both SP and histamine to immediate hypersensitivity reactions supports the utility of NK-1 and H1 receptor antagonist therapy. MDL 108,207DA incorporates both activities into the same compound and, as a result, may be useful in the treatment of allergic diseases.

Lung cancer practice guidelines: lessons learned and issues addressed by the Ontario Lung Cancer Disease Site Group

PURPOSE

The primary objective was to identify the lessons learned and issues addressed by the Disease Site Group (DSG) developing guidelines on lung cancer for practitioners in the province of Ontario.

METHODS

The minutes of the Ontario Lung Cancer Disease Site Group (LCDSG) and the meeting notes of a medical sociologist who attended all LCDSG meetings were reviewed to identify the disease-specific and generic issues addressed by the LCDSG during guideline development.

RESULTS AND CONCLUSION

The Ontario LCDSG has completed three practice guidelines and has five evidence-based recommendations (EBRs) in production. Topics for guideline development were selected on the basis of known practice variability (eg, advanced-stage non-small-cell lung cancer [NSCLC]); the size of the patient population that could potentially be affected by the guideline; results of phase II trials of new and potentially expensive agents (vinorelbine, paclitaxel, and docetaxel); and randomized controlled clinical trials that support new practice standards (combined modality therapy for unresectable stage III NSCLC). The wording of each EBR reflects the strength and quality of the evidence in support of the treatment option, the primary outcome(s), and the individual physician and discipline values concerning treatment outcomes in the absence of known patient values.

Phase II study of a one hour paclitaxel infusion in combination with carboplatin for advanced non-small cell lung cancer

PURPOSE

To determine the activity, toxicity, and optimal dose of paclitaxel when given by one hour infusion combined with carboplatin in advanced non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Thirty-seven previously untreated patients with stage IIIB or IV NSCLC were enrolled. Paclitaxel was administered by one hour infusion at a dose of 175 mg/m2 for the first cycle, and was escalated up to 255 mg/m2 over successive cycles if tolerated. In the absence of toxicity, the carboplatin dose was kept constant at an area under the concentration-time curve (AUC) of 6. Cycles were repeated at 3-week intervals until progression or intolerable toxicity occurred.

RESULTS

Thirty-six patients were evaluable for toxicity and survival, and thirty-five for responses. The partial response rate was 10 of 35 (29%) and there were no complete responses. The median duration of response was 4.8 months (range 0.5-11.7 months). The median survival duration was 6.5 months, and 1 year survival was 31%. The mean paclitaxel dose was 188 mg/m2. Treatment was generally well tolerated. Four patients (11%) had febrile neutropenia. Five patients (14%) had grade 3 neuropathy, and 4 (11%) had grade 3 nausea and vomiting. Minor toxicities included alopecia, myalgias, arthralgias and stomatitis.

CONCLUSIONS

Paclitaxel and carboplatin is a well-tolerated regimen that can safely be given by a one hour paclitaxel infusion. The modest response rate observed in this study may be due to either the low dose-intensity of paclitaxel or the short infusion duration. Further trials to optimize the relative doses of paclitaxel and carboplatin are needed.

Ribonucleotide reductase--structural studies of a radical enzyme

Ribonucleotide reductase contains a stable organic free radical essential for its activity located on a tyrosine residue in the small subunit of the enzyme called R2. The substrate binding site is, however, found in the catalytic subunit called R1. A long-range protein-mediated radical transfer pathway appears to be responsible for the delivery of the radical from the tyrosine in R2 to the substrate on R1. The active site is located deep inside the protein in a very stable beta/alpha-barrel structure and a hydrogen bonded system leads from the surface to Cys439 at the active site which is in excellent position to remove a hydrogen from the 3' of the ribose of a bound substrate nucleotide.

Paclitaxel plus hydroxyurea as second line therapy for non-small cell lung cancer

We tested paclitaxel (Taxol) and low dose hydroxyurea as second line therapy in 30 patients with non-small cell lung cancer since both drugs are active against non-small cell lung cancer in other settings, and since hydroxyurea may reverse chemotherapy resistance by disrupting double minute chromosomes. Hydroxyurea 500 mg was given orally each Monday, Wednesday, Friday starting 1 week before paclitaxel, and continuing until removal from study. Paclitaxel 135 mg/m2 was given i.v. over > or = 1 h every 3 weeks with dexamethasone, diphenhydramine, and ranitidine. Patients could have paclitaxel doses escalated to 175 mg/m2 in course 2 and to 200 mg/m2 in course 3, where tolerated. Sixteen males and 14 females were treated. All patients had previously received a single cisplatin-based chemotherapy regimen and 23 had previously received radiotherapy. Twelve patients had adenocarcinomas, six had squamous cell carcinomas, and 12 had large cell carcinomas. Eight patients had Stage IIIb cancers and 22 had Stage IV. Paclitaxel doses were 135 mg/m2 in 56 courses, 175 mg/m2 in 24, and 200 mg/m2 in 15. Treatment was well tolerated. Median granulocyte nadirs were 2.5 (x 10(9)/l) for paclitaxel 135 mg/m2, 1.8 for 175 mg/m2, and 1.3 for 200 mg/m2. No patient developed febrile neutropenia, and none required a dose reduction. Two patients had reversible anaphylaxis. Other toxicities were quite tolerable. They included fatigue, myalgias, dizziness, paresthesias, diarrhea, alopecia, mucositis, flushing, headache, swollen red hands, and anxiety. One patient had a partial remission and 15 had stable disease (including six with minor responses). Median survival was 20 (95% CI, 12-34) weeks, with 19% of patients remaining alive at 1 year from initiation of treatment. This is a well-tolerated regimen with modest activity as second line chemotherapy for patients with non-small cell lung cancer previously treated with cisplatin regimens. Higher doses would be feasible and other strategies are now being explored.

Structural comparison of two strains of foot-and-mouth disease virus subtype O1 and a laboratory antigenic variant, G67

BACKGROUND

Foot-and-mouth disease viruses (FMDVs) are members of the picornavirus family and cause an economically important disease of cloven-hoofed animals. To understand the structural basis of antigenic variation in FMDV, we have determined the structures of two viruses closely related to strain O1BFS whose structure is known.

RESULTS

The two new structure are, like O1BFS, both serotype O viruses. The first, O1 Kaüfbeuren (O1K), is a field isolate dating from an outbreak of FMD in Europe in the 1960s. The second, called G67, is a quadruple mutant of O1K, generated in the laboratory, that bears point mutations conferring resistance to neutralizing by monoclonal antibodies, specific for each of the four major antigenic sites defined previously. The availability of the three related virus structures permits a detailed analysis of the way amino acid substitutions influence antigenicity. Structural changes are seen to be limited, in general, to the substituted side chain. For example, the GH loop of VP1, a highly antigenic and mobile protuberance which becomes ordered only under reducing conditions, was essentially indistinguishable in the three viruses despite the accumulation of up to four changes within its 15-residue sequence. At one of the other antigenic sites, however, changes between the two field strains did perturb both side-chain and main-chain structures in the vicinity.

CONCLUSIONS

The conservation of conformation of the GH loop of VP1 adds to the evidence implicating an integrin as the cellular receptor for FMDV, since this loop contains a conserved RGD (Arg-Gly-Asp) sequence structurally similar to the same tripeptide in some other integrin-binding proteins. Structural changes required for the virus to escape neutralization by monoclonal antibodies are generally small. The more extensive type of structural change exhibited by the field isolates probably reflects differing selective pressures operating in vivo and in vitro.

Mixed germ cell malignancy of the ovary concurrent with pregnancy

BACKGROUND

A rare malignant germ cell tumor of the ovary during pregnancy was detected by screening of maternal serum alpha-fetoprotein (MSAFP). Treatment of this uncommon tumor during pregnancy incorporated combination chemotherapy including etoposide.

CASE

An 18-year-old primiparous woman undergoing antenatal genetic screening was found to have an extremely elevated MSAFP of 477.8 IU/mL, or 12.46 multiples of the median. Oophorectomy and staging laparotomy at 20.5 weeks' gestation resulted in the diagnosis of mixed germ cell tumor of the ovary, with both endodermal sinus tumor and grade 3 immature teratoma. The patient received three courses of cis-platinum, etoposide, and bleomycin. Maternal serum AFP titers had returned to normal pregnancy levels by the start of the second course. A healthy female infant was delivered at 39 weeks' gestation following induction of labor for pregnancy-induced hypertension.

CONCLUSION

Elevated MSAFP levels may be a presenting sign of malignant ovarian germ cell neoplasms. This report describes both surgical and chemotherapeutic treatment of a germ cell malignancy during pregnancy, with delivery at term. To date, major fetal toxicity from chemotherapy has not been identified.

Addition of pentoxifylline plus nifedipine to chemotherapy in patients with cisplatin-resistant cancers of the lung and other sites

Eight evaluable patients with cisplatin-resistant non-small cell lung cancer (6 patients), small cell lung cancer (1 patient), or both breast and ovarian cancer (1 patient) were entered on a study to determine whether the addition of nifedipine plus pentoxifylline to cisplatin-based chemotherapy would result in increased chemotherapy efficacy. No patient responded to treatment. Myelosuppression may have been augmented by the nifedipine and pentoxifylline (median granulocyte nadir, 0.3 x 10(9)/L). Two patients developed febrile neutropenia. Nifedipine and pentoxifylline had to be stopped in two evaluable patients due to hypotension, and three additional inevaluable patients withdrew from the study due to nifedipine-pentoxifylline toxicity before receiving their chemotherapy. There was no indication that other types of chemotherapy toxicity were increased by the addition of nifedipine and pentoxifylline. A major problem with the strategy followed in this protocol was that patients whose tumors had failed to respond to cisplatin-based regimens were often too ill to tolerate additional cisplatin, particularly when accompanied by nifedipine-associated hypotension.

The structure of an immunodominant loop on foot and mouth disease virus, serotype O1, determined under reducing conditions

Residues 136-159 of VPI of foot and mouth disease virus (FMDV) comprise the G-H loop of the protein and form a prominent feature on the surface of virus particles. This sequence contains an immunodominant neutralizing epitope, which can be mimicked with synthetic peptides, and includes an Arg, Gly, Asp motif which has been implicated in the binding of the virus to cellular receptors. Crystallographic analysis of native virus particles failed to resolve the structure of this region due to its disordered state. However, reduction of a disulphide bond between cysteine residues 134 of VP1 and 130 of VP2 caused the G-H loop to collapse onto the surface of the virus particle and allowed its conformation to be determined.