A case-control study of the androgen receptor gene CAG repeat polymorphism in Australian prostate carcinoma subjects

BACKGROUND

The development of prostate carcinoma is androgen-dependent. The coding sequence of the androgen receptor (AR) gene contains a CAG repeat polymorphism that has been shown to influence AR activity in vitro. Studies of this polymorphism as a prostate carcinoma risk factor have been conflicting.

METHODS

A matched case-control design was used in a clinic-based multicenter study of Australian prostate carcinoma subjects. Cancer subjects were matched by age and locality with controls, all of whom had a serum prostate specific antigen (PSA) level of less than 4 mg/L. Conditional logistic regression was used to determine the relative risk of prostate carcinoma dependent on AR gene CAG number. The association of disease characteristics at diagnosis with the polymorphism also was assessed.

RESULTS

Five hundred forty-five cases of prostate carcinoma and 456 matched case-control pairs were recruited. Association studies of disease characteristics at diagnosis showed age at diagnosis to be associated with AR CAG number by univariate (P = 0.004) and multivariate (adjusting for PSA, stage, and grade) linear regression (P = 0.018). No association was observed between the polymorphism and disease stage (TNM-based categories; P = 0.277), histologic grade (P = 0.41), or PSA level at diagnosis (P = 0.48). In the pairwise case-control analysis, the odds ratio of prostate carcinoma for a change of 5 CAG repeats gave an odds ratio of 0.9821 (95% confidence interval, 0.84-1.15).

CONCLUSIONS

In this Australian study population, the AR CAG repeat polymorphism was not a risk factor for prostate carcinoma, but a shorter repeat sequence was associated with earlier age at diagnosis.

The GP-hospital interface: attitudes of general practitioners to tertiary teaching hospitals

OBJECTIVE

To assess general practitioner (GP) perceptions of liaison with two local tertiary teaching hospitals.

DESIGN

Questionnaire-based survey of GP attitudes.

SETTING

Melbourne and North West Melbourne Divisions of General Practice, in July and September 1994.

PARTICIPANTS

All GPs (587) practising in the Divisions (identified from Health Insurance Commission lists of consultations charged at GP rates).

OUTCOME MEASURES

Degree of agreement on a 5-point Likert scale to statements about GP-hospital liaison, and relevant open comments.

RESULTS

350 GPs (60%) responded, including 84% of vocationally registered GPs; 68% of the 350 were in full-time practice and 70% had been in practice for over 10 years. GPs had no clear strategy for obtaining admission of semi-urgent patients to public hospitals. For patients needing urgent admission, almost a third of GPs sometimes resorted to sending them to the emergency department without first telephoning. Most GPs agreed that hospitals did not notify them of patient admission (84%), major changes in patient condition, including death (87%), and patient discharge (75%). Most would interrupt a consultation to discuss a patient with hospital staff (92%). About half agreed they had poor access to outstanding results, and 65% were concerned that proposed early-discharge practices would be detrimental to patient care.

CONCLUSIONS

The survey identified considerable GP dissatisfaction with hospital-GP communication and GP willingness to be more involved in liaison and communication with hospitals about patient care. Changes in hospital organisation and hospital staff attitudes are needed to allow this.