METHODS

As part of a larger, retrospective study of the experience of those counselled for the familial occurrence of colorectal cancer, we investigated the psychosocial impact of receiving a negative DNA test result. The study comprised all those counselled for the familial occurrence of colorectal cancer at three family cancer clinics in Amsterdam during the period 1986–98. Both asymptomatic subjects and those ever treated for cancer were invited to participate in the study. The study was approved by the institutional ethics committees of the three participating hospitals.

Of the 214 counsellees eligible for the overall study, 178 returned a completed questionnaire (83%). Among the 178 respondents, 25 were established to be non-carriers of the pathogenic mutation detected in their families (response within non-carriers 83%), and 31 were found to be carriers of a pathogenic HNPCC mutation (response within carriers 84%). The remaining 122 counsellees received a risk estimation and screening advice based on their family history only, either because DNA testing was not available or performed at the time they were counselled (n=108) or because the DNA test yielded inconclusive results (n=14). In this letter, we report data on the HNPCC mutation negative and positive counsellees.

As part of a self-report questionnaire assessing a wide range of psychosocial issues, three questions adapted from Lerman et al¹² were posed about the prevalence of cancer worries: “During the past year, how frequently did you worry about the risk of developing cancer”, “During the past year, how frequently did your worries about cancer have an impact on your daily functioning?”, and “During the past year, how frequently did you worry about the risk of cancer in members of your family”. Response categories included “almost never”, “sometimes”, “often”, and “almost always”. Those found to be HNPCC mutation negative were also asked to answer the following questions: “When were you told that colonoscopies were no longer necessary?”, “Did you undergo colon screening before this date?”, “Did you undergo colon screening after this date?”, “Are you pleased that colon screening is no longer necessary?”, and “Are you concerned about having been discharged from colon screening?”. The questionnaire was sent, on average, four years (SD 2 years, median 3 years) after they had received their final counselling session during which, if tested, personal DNA test results were discussed.

RESULTS

The HNPCC mutation negative counsellees comprised 12 men and 13 women with a mean age of 48 years at the time of completion of the questionnaire (SD 9 years, range 29–63 years). Of these 25 counsellees, three had been treated for benign polyps in the past; the remaining 22 had no personal history of polyps or cancer. The mean age of 31 mutation positive counsellees was 42 years (SD 10 years, range 26–58 years). Of the 18 male and 13 female carriers, 10 had been treated for polyps or colorectal cancer in the past.

As shown in table 1, none of the non-carriers reported being “often”, or “almost always” worried about their own cancer risk, compared to 19% of the carriers (p=0.06). Only a small percentage of the non-carriers and carriers (3% and 4%, respectively) reported that concerns about cancer had had a significant impact on their daily functioning during the past year. Relatively few respondents reported being frequently concerned about the risk of cancer for other family members (12% and 13% for the non-carriers and carriers, respectively).

Of the 25 non-carriers, one had never had a colonoscopy, 10 had undergone one colonoscopy, six had had two colonoscopies, and eight had had three or more colonoscopies. Of the 22 counsellees who responded to the questions about discharge, most (82%) were pleased with the fact that they no longer needed to undergo screening. However, of the 22 respondents, seven (32%) reported that they were concerned with their discharge from screening. Of these seven, three had also reported that they were pleased that the screening was no longer required, suggesting the presence of conflicting feelings. Only one counsellee reported having undergone a colonoscopy about one year after having been discharged from the surveillance programme. This woman had been under surveillance since 1975 and had no personal history of polyps or cancer. Her motives for undergoing colonoscopy after having been discharged were unclear.

DISCUSSION

These results suggest that, although worries about developing colorectal cancer are infrequent and most non-carriers are pleased that colonoscopies are no longer necessary, about one-third of non-carriers have some concerns about stopping surveillance. The reasons for these concerns are unclear. It might be that, as in the study by Michie et al,¹¹ some people doubt the accuracy of the genetic test results. This issue should be investigated in future studies, preferably with larger samples and using a prospective design. Although it is generally accepted that discharge from surveillance is one of the greatest benefits of genetic counselling for colorectal cancer, clinical geneticists and gastroenterologists need to be aware of the fact that, for some HNPCC mutation negative family members, concerns remain. During the final consultation with the geneticist or gastroenterologist, these concerns should be addressed and, depending on local guidelines, participation in a general population surveillance programme might be recommended.