Joan Slack

Screening and genetic counselling for relatives of patients with colorectal cancer in a family cancer clinic.

OBJECTIVE--To introduce and monitor a screening programme for first degree relatives of patients with colorectal cancer based on their calculated lifetime risk. DESIGN--Lifetime risks were calculated for first degree relatives of patients with colorectal cancer and used to offer screening based on estimated risk. SETTING--A family cancer clinic was set up as part of the North East Thames Regional Genetic Service for relatives of patients who had developed colorectal cancer before the age of 45 and members of families in which multiple cancer had occurred. PATIENTS--Self referrals as well as patients referred by general and hospital practitioners. INTERVENTION--Relatives with a lifetime risk of 1 in 10 or greater (high risk group) were offered screening five yearly by colonoscopy, and those whose risk was between 1 in 10 and 1 in 17 were offered yearly screening for faecal occult blood. Women with family histories compatible with Lynch type II cancer family syndrome were offered screening for breast and pelvic tumours. RESULTS--In four years 715 patients were seen. Acceptance of screening was 90% (644 patients). Of 151 patients screened for faecal occult blood, two were found to have polyps. This screening test was unsatisfactory for the high risk group, having a negative predictive value of 78% in 59 patients tested. Regular screening by colonoscopy was offered to 382 high risk patients; 62 patients with polyps and five with colonic cancer were found. One hundred and ten pedigrees were identified with the Lynch type II cancer family syndrome, and four of 35 women screened were found to have breast cancer. Of 14 relatives aged over 65 with a 1 in 2 risk of site specific colonic cancer or Lynch type II cancer family syndrome, seven were found to have polyps, one of whom had carcinoma in situ. CONCLUSIONS--Family history can be used to identify those at risk of colonic cancer and to target appropriate screening. Colonoscopy detected a high number of premalignant colonic polyps, but faecal occult blood testing was unsatisfactory for those at high risk of colorectal cancer.

Presenting a routine screening test in antenatal care: Practice observed

Peoples knowledge of screening tests for which they are eligible and which they may have undergone is frequently low. The aim of the current study is to determine the extent to which this is due to how a test is offered and explained. Routine consultations (n = 102) between midwives, obstetricians and pregnant women were tape-recorded to determine how a routine screening test for fetal abnormalities (maternal serum alpha-fetoprotein) is presented. The test was presented in the vast majority of consultations. Overall, little information was provided about the test, the conditions screened for, and the meaning of either a positive or a negative result. Screening was presented in such a way as to encourage women to undergo the test. The way in which routine prenatal screening is presented is unlikely to maximise informed decisions about whether to participate in this screening programme. Factors likely to be influencing test presentation include knowledge, attitudes and skills of staff, as well as the attitudes of pregnant women. The results of this study highlight a need to train the heath professionals implementing screening programmes in how to inform people fully about low probability but serious events without alarming them unduly, or reassuring them falsely.

Perceived risk not actual risk predicts uptake of amniocentesis

Summary. A consecutive cohort of 71 women eligible for amniocentesis because they were over 38 years of age completed questionnaires during the first trimester of pregnancy. Sixty‐one women underwent amniocentesis, an uptake rate of 86%. Uptake was associated with a less negative attitude towards termination of an affected baby and a higher perceived risk of the fetus being abnormal. It was not associated with actual age‐related risks. There was no significant relation between actual risk and perceived risk. The results of this study suggests that it is important for doctors to understand the basis of womens decisions to have amniocentesis, and the difference between actual and perceived risk if they are to communicate effectively with women about the test and their options.

Development of a self-administered questionnaire to measure women's knowledge of prenatal screening and diagnostic tests

A prerequisite to an informed decision to undergo any screening or diagnostic test is knowledge about such a test. This study describes the development of a self-administered questionnaire to measure knowledge of prenatal tests, for use in studies concerning the uptake of these tests. Both the reliability (internal and test-retest) and predictive validity are evaluated. Validity is assessed in two studies: first, comparison is made between three criterion groups (two with experience of pregnancy, one without); and second, scores on the questionnaire are compared before and after women have been provided with information about possible tests. The results show this to be both a reliable and valid measure of knowledge about prenatal tests. The results also highlight aspects of knowledge that are lacking. For example, a sizeable minority of women were uncertain or incorrect in identifying which tests they had undergone in a recent pregnancy.

Family history and risk of breast cancer.

The risk of breast cancer in first degree relatives of patients with breast cancer can be derived from family history and is dependent upon the age at diagnosis in the index patient. For the relatives of index patients older than 55, the relative risk is 1.57, if less than 55 the relative risk is 2.29, and 3.85 if less than 45 (95% confidence limits 0.83 to 2.68, 1.18 to 4.01, and 1.67 to 3.85, respectively). First degree relatives of patients with bilateral breast cancer have a 6.43-fold increase in risk (95% confidence limits 1.32 to 18.77). The genetic contribution to overall lifetime liability to breast cancer in the relatives declines rapidly with increasing age of onset of breast cancer in the index patient from 37% at 20 years to 8% by 45 years. This information can be used in clinical practice for counselling and the establishment of screening programmes.

Psychological models in predicting uptake of prenatal screening.

Abstract The purpose of the current study was to determine which psychological models are most useful in predicting uptake of a prenatal screening test, maternal-serum alphafetoprotein screening for spina bifida and Downs syndrome. 1000 women eligible for the test completed standardised self-report questionnaires at two routine clinic visits to an antenatal clinic prior to the time when the test could take place. 902 underwent the screening test; 51 declined the test; and 47 did not undergo the test, giving no reason for this to staff. Knowledge of the test, the subjective expected utility attached to the test, and attitudes to doctors and medicine were all significant predictors of uptake behaviour. Results of a discriminant function analysis demonstrated distinct psychological processes underlying each of these three uptake behaviours, explaining 21% of the variance in uptake of screening. If uptake of screening is examined not as a dichotomous variable but as a group of behaviours, predictive models a...

Factors influencing the uptake of screening for open neural‐tube defects and amniocentesis to test for Down's syndrome

The study assesses relationship between uptake of prenatal screening tests and women attitudes about these tests and pregnancy. All 218 women studied had asked for tests. Various questionnaires and rating scales are used

An economic appraisal of screening for Down's syndrome in pregnancy using maternal age and serum alpha fetoprotein concentration.

The direct and indirect costs and benefits of expanding the existing screening programme for Downs syndrome by using maternal age and serum alpha fetoprotein concentrations have been calculated using an ascertainment of Downs syndrome pregnancies from the North East Thames Regions in 1982. In addition, a possible approach to evaluating the total costs and benefits to the families concerned is presented. If the uptake of the proposed screening programme is maximal, the replacement rate is zero and a discount rate of 5% is used, the benefit cost ratio is 23.6. If the uptake of the programme is 50%, the replacement rate is 100% and a discount rate of 7% is used, the benefit cost ratio is 12.2. The proposed screening programme, based upon a risk of Downs syndrome of at least 1 in 220 using maternal age and serum alpha fetoprotein is both equitable for families at risk and of economic benefit to both families and society.

PSYCHOLOGICAL EFFECTS OF HAVING AMNIOCENTESIS: ARE THESE DUE TO THE PROCEDURE, THE RISK OR THE BEHAVIOUR?

The purpose of the study was to examine the impact of amniocentesis on women at risk for having a baby with Downs syndrome because of raised maternal age. Fifty-four of the study participants had amniocentesis and nine did not. At the time of the procedure, those having amniocentesis were significantly more anxious, less certain about the babys health, and held more negative attitudes towards the baby than women who did not undergo amniocentesis. For women undergoing amniocentesis there was a positive association between perceived risk of having an abnormal baby and anxiety. After the babys birth, women who had undergone amniocentesis held less positive attitudes to the baby and were significantly more worried about the babys health. These results suggest that the anxiety surrounding amniocentesis is related both to the procedure and to the perceived likelihood of an abnormal result. The differences between the groups after the birth seem more likely to reflect pre-existing attitudinal differences between the two groups, than the effects of amniocentesis.

Risk of ovarian cancer and genetic relationship to other cancers in families.

The risk of ovarian and other cancers was assessed in first-degree relatives of patients with ovarian cancer from an analysis of 391 pedigrees. Overall there was a significant increase in the risk of ovarian cancer (4.5-fold; p < 0.001). The risks were 14.2- (p < 0.001), 5.2- (p < 0.001) and 3.7-fold (p < 0.001) for relatives of patients diagnosed before 45, between 45 and 54 and after the age of 55, respectively. There was no significant increase in the risk of cancers of the uterus, stomach, lung, colorectum or prostate. There was, however, an overall increase in the risk of breast cancer (1.3-fold; p < 0.05). The risk was highest for those relatives of patients diagnosed with ovarian cancer before the age of 55 (2.2-fold; p < 0.01). These results support the role of genetic factors in the aetiology of ovarian cancer and provide further evidence for the existence of a breast-ovarian family cancer syndrome, which may result from the pleiotropic effects of the same gene in some families.