1031
young
women
who had their first pregnancy
at an un-
usually early age. Pregnancy at an early age may therefore be a factor in the development of the disease. In addition the data from the adolescent study confirm our findings that cell changes do not appear until 4 or more years after the first pregnancy. DISCUSSION
Approximately 1-6% of young women have abnormal cells in uterine cervical smears, and at least half of these smears will become normal without treatment. Although the number of atypical cases discussed in this paper is small, the data suggest that-provided follow-up by smears is practicable-immediate further investigations are not necessarily essential. Girls with atypical smears can be left for variable periods of time and through several pregnancies. This will be important to young women who wish to have a family. It is unlikely that anything more serious than a carcinoma-in-situ lesion will develop before the age of 25. At worst a lesion will become microinvasive. Routine screening of healthy very young girls therefore seems to be of doubtful value. It is likely that all patients whose lesions progress to preclinical cancer will have been pregnant. The findings of the adolescent study reinforce this statement. The part played by pregnancy in the development of cervical cancer has not been adequately examined, although several studies have shown that the risk of developing this disease increases when high parity has been reached at an early age. 1.8,9 Early first pregnancy and high parity at young ages may be associated with having had more than one sexual partner. The younger the age at marriage, the greater the probability of a prenuptial conception. Young age at marriage is associated with a high rate of divorces, but remarriage continues to be popular.6However, other studies have indicated that many young pregnant girls are in stable and continuing, though not necessarily long-term, relationships. 10 The connection between early pregnancy and serial relationships merits further investigation. Research in this direction is complicated by the role and availability of oral contraception. Patients with preclinical cancer in this study did not use the contraceptive pill before they had had at least one pregnancy. Some of the girls had more than one partner. In some cases in the adolescent study the relationship with the father of the first pregnancy did not continue. Some young women will start oral contraception as soon as they become sexually active. It is possible that such girls may have more sexual partners than the girls in our studies, the difference being that women in the group who use contraception do not become pregnant. If pregnancy at an early age is a key factor in the genesis of cervical cancer, then oral contraception, by reducing the number of pregnancies at young ages may reduce the incidence of the disease. Further work is necessary to establish the interactions between sexual, contraceptive, and reproductive behaviour in young women in order to establish any links with the incidence of clinical cervical cancer.
which might have been expected in association with the change in social mores and the widespread use of oral contraception has riot happened.’ 2. About 60% of the atypical smears in young women will revert to normal without treatment. 3. Only 11% of young women with atypical smears will progress to preclinical cancer, and the lesion will be at the in-situ stage at biopsy several years later. 4. The girls who develop preclinical cancer have had a pregnancy, usually at an early age; and they do not attend family-planning clinics until after their pregnancy. 5. Oral contraception, by preventing pregnancy at an early age, might help to reduce the incidence of cervical cancer.
should be part of obstetric care. the first Screening during pregnancy and re-screening at or at 5-yearly intervals should subsequent pregnancies cover the young women who are at risk of developing cervical cancer. Routine well-women screening need not be carried out on women under 25. 6. A cervical
smear
We thank the obstetricians and
gynaecologists
who treated these pa-
tients, and we thank Mrs Kathleen Swanson and Mrs Elizabeth Bruce for their help.
Requests for reprints should be addressed to J.E.M., Department of Pathology, University Medical Buildings, Foresterhill, Aberdeen, AB9 2ZD. REFERENCES
Macgregor, J. E. Tumori, 1976, 62, 287. Lawson, J. G.J. Obstet. Gynœc. Br. Emp. 1956, 64, 819. 3. Macgregor, J. E., Teper, S. Lancet, 1974, i, 1221. 4. Can. med. Ass.J. 1976, 114, 971 5. British Society for Clinical Cytology, Br. med.J. 1977, i, 1516. 6. Registrar General for Scotland. Annual report. H.M. Stationery Office, Edinburgh, 1976. 7. Teper, S. Unpublished. 1. 2.
8. See Rotkin, I. D. Cancer Res. 1973, 3 1353. 9. Aitken-Swan, J., Baird, D. Br. J. Cancer, 1966, 20, 642. 10. McEwan, J. A., Owens, C., Newton, J. R.J. biosoc. Sci. 1974,
6, 357.
Public Health MORTALITY FROM CARCINOMA OF THE CERVIX
ROBERT YULE Christie Hospital and Holt Radium Institute, Manchester M20 9BX
Withington,
was a small decrease in deaths from carcinoma of the cervix in England and Wales between 1970 and 1976. However, whilst there has been a significant improvement in the age-group 35-54 years, the number of deaths in women under 35years of age has doubled.
THERE
Deaths From Carcinoma
of Cervix (England and Wales) By
Age and Year
CONCLUSIONS
1. The absolute number of young women with abnormal smears is increasing, although the proportion with abnormal smears has not risen. A relative increase
The increase in deaths in younger women is widely held to be associated with the early onset of sexual activity in the young and with the increased use of non-bar-
1032 rier contraceptives, particularly the contraceptive pill and intrauterine devices which offer no protection against the transmissible agent, be it virus or spermatozoa, thought to be responsible for the disease. The North Western Region has developed the most advanced screening programme in the U.K. for the detection of pre-cancerous lesions of the cervix. Computerisation of the records system has also enabled us to analyse the large number of cyto-tests performed in this region in a way that would be impossible otherwise. In 1965, a total of 5171 tests were examined; in 1977 this number had reached 188 047, and the records now contain a total of 1476 865 tests from 696 768 women. Whilst this is a gratifying achievement, we are always conscious of the fact that, according to the 1971 census, we have some 1.5million women over the age of 20 years in the region. We have been especially successful in involving the general practitioners (G.P.s) in the screening programme.
The pre-invasive phase of carcinoma of the cervix may be shorter in younger women, leading more quickly to an aggressive invasive tumour, which is less likely to be prevented by routine screening, unless the interval between tests is short; or we may tend to test women at low risk. Indeed both of these factors may be operating. Conversely, in older women, we may be more effective in screening the high-risk segment. The pre-invasive stage may be longer, invasive growth a less frequent and less aggressive sequel. The Department of Health and Social Security encourages, by payments to general practitioners, the screening of older women. This conflicts with the findings in this paper. It is time to take note of the changes in sexual activity and contraceptive practice in younger women in the U.K. Since these women are not likely to abandon the contraceptive pill and return to the diaphragm and condom, the detection of pre-cancerous conditions of the cervix must be ensured by widespread and frequent cyto-testing.
Occupational Until recently, we were able to recall women for testing every three years, but financial stringency has compelled us to change to a five-yearly recall, in line with the national scheme. We believe that the increased frequency of testing contributed to an improvement in the incidence of, and mortality from, carcinoma of the cervix in the North Western Region which exceeds the improvement in the country as a whole. Data from the Registrar General show an improvement of 11-8% in deaths from carcinoma of the cervix in England and Wales, while the improvement in the North-Western Region over the same period of time was 15.2%. There was a progressive reduction in the numbers of women presenting for the first time to the Christie Hospital with clinical cervical cancer:
Despite the fact that in the North Western Region (and probably in England and Wales generally) the largest increase in cyto-testing occurred in women under 35 years of age, deaths in this age-group have increased. Also the rate of detection of pre-cancerous conditions of the cervix did not increase in this group from 1970 to 1977, although there was a significant increase in older women.
Positive
Cyto-test Rates (1970 and 1977) (North
Western
Region)
It seems that, although we are testing increasingly large numbers of young women, such screening is relatively ineffective in detecting pre-cancerous lesions leading to the prevention of death from invasive carcinoma.
Health
OCCUPATIONAL EXPOSURE TO IONISING RADIATION THE RISK IN PERSPECTIVE*
J. A. BONNELL
G. HARTE
Nuclear Health and Safety Department and Berkeley Nuclear Laboratories, Central Electricity Generating Board, London
IN its latest recommendations the International Commission on Radiological Protection has formulated its new protection philosophy. Having classified the biological effects of radiation exposure as "stochastic" and "non-stochastic", the document states that the aim of radiation protection should be to prevent non-stochastic effects (such as cataract of the lens and non-malignant skin damage for which the severity of the effect varies with dose) and to limit the probability of stochastic effects to an acceptable level. The stochastic effects of irradiation are those for which the probability of occurrence of the effect is a function of dose. Carcinogenesis-the chief somatic effect of irradiation at low doses-is stochastic, as is the induction of genetic
damage. In pursuance of its aims, the Commission has moved away from the concept of limiting the dose to a critical organ, and now recommends a protection procedure which takes account of the total risk attributable to the exposure of all irradiated tissues in the body. A protection system based on risk limitation involves the assignment of a risk per unit dose to the tissues of the body susceptible to the induction of stochastic effects, and table i lists the risk factors put forward by the Commission. These risk factors may be used in conjunction with postulated exposure regimens to estimate the risk to an average member of the working population or of the general public arising from the operation of nuclear power plants. * Based on a paper presented at an international symposium on the late biological effects of radiation held in Vienna on March 13-17, 1978, and published in this form by courtesy of the Editor of the Proceedings of the Conference.
young
women
who had their first pregnancy
at an un-
usually early age. Pregnancy at an early age may therefore be a factor in the development of the disease. In addition the data from the adolescent study confirm our findings that cell changes do not appear until 4 or more years after the first pregnancy. DISCUSSION
Approximately 1-6% of young women have abnormal cells in uterine cervical smears, and at least half of these smears will become normal without treatment. Although the number of atypical cases discussed in this paper is small, the data suggest that-provided follow-up by smears is practicable-immediate further investigations are not necessarily essential. Girls with atypical smears can be left for variable periods of time and through several pregnancies. This will be important to young women who wish to have a family. It is unlikely that anything more serious than a carcinoma-in-situ lesion will develop before the age of 25. At worst a lesion will become microinvasive. Routine screening of healthy very young girls therefore seems to be of doubtful value. It is likely that all patients whose lesions progress to preclinical cancer will have been pregnant. The findings of the adolescent study reinforce this statement. The part played by pregnancy in the development of cervical cancer has not been adequately examined, although several studies have shown that the risk of developing this disease increases when high parity has been reached at an early age. 1.8,9 Early first pregnancy and high parity at young ages may be associated with having had more than one sexual partner. The younger the age at marriage, the greater the probability of a prenuptial conception. Young age at marriage is associated with a high rate of divorces, but remarriage continues to be popular.6However, other studies have indicated that many young pregnant girls are in stable and continuing, though not necessarily long-term, relationships. 10 The connection between early pregnancy and serial relationships merits further investigation. Research in this direction is complicated by the role and availability of oral contraception. Patients with preclinical cancer in this study did not use the contraceptive pill before they had had at least one pregnancy. Some of the girls had more than one partner. In some cases in the adolescent study the relationship with the father of the first pregnancy did not continue. Some young women will start oral contraception as soon as they become sexually active. It is possible that such girls may have more sexual partners than the girls in our studies, the difference being that women in the group who use contraception do not become pregnant. If pregnancy at an early age is a key factor in the genesis of cervical cancer, then oral contraception, by reducing the number of pregnancies at young ages may reduce the incidence of the disease. Further work is necessary to establish the interactions between sexual, contraceptive, and reproductive behaviour in young women in order to establish any links with the incidence of clinical cervical cancer.
which might have been expected in association with the change in social mores and the widespread use of oral contraception has riot happened.’ 2. About 60% of the atypical smears in young women will revert to normal without treatment. 3. Only 11% of young women with atypical smears will progress to preclinical cancer, and the lesion will be at the in-situ stage at biopsy several years later. 4. The girls who develop preclinical cancer have had a pregnancy, usually at an early age; and they do not attend family-planning clinics until after their pregnancy. 5. Oral contraception, by preventing pregnancy at an early age, might help to reduce the incidence of cervical cancer.
should be part of obstetric care. the first Screening during pregnancy and re-screening at or at 5-yearly intervals should subsequent pregnancies cover the young women who are at risk of developing cervical cancer. Routine well-women screening need not be carried out on women under 25. 6. A cervical
smear
We thank the obstetricians and
gynaecologists
who treated these pa-
tients, and we thank Mrs Kathleen Swanson and Mrs Elizabeth Bruce for their help.
Requests for reprints should be addressed to J.E.M., Department of Pathology, University Medical Buildings, Foresterhill, Aberdeen, AB9 2ZD. REFERENCES
Macgregor, J. E. Tumori, 1976, 62, 287. Lawson, J. G.J. Obstet. Gynœc. Br. Emp. 1956, 64, 819. 3. Macgregor, J. E., Teper, S. Lancet, 1974, i, 1221. 4. Can. med. Ass.J. 1976, 114, 971 5. British Society for Clinical Cytology, Br. med.J. 1977, i, 1516. 6. Registrar General for Scotland. Annual report. H.M. Stationery Office, Edinburgh, 1976. 7. Teper, S. Unpublished. 1. 2.
8. See Rotkin, I. D. Cancer Res. 1973, 3 1353. 9. Aitken-Swan, J., Baird, D. Br. J. Cancer, 1966, 20, 642. 10. McEwan, J. A., Owens, C., Newton, J. R.J. biosoc. Sci. 1974,
6, 357.
Public Health MORTALITY FROM CARCINOMA OF THE CERVIX
ROBERT YULE Christie Hospital and Holt Radium Institute, Manchester M20 9BX
Withington,
was a small decrease in deaths from carcinoma of the cervix in England and Wales between 1970 and 1976. However, whilst there has been a significant improvement in the age-group 35-54 years, the number of deaths in women under 35years of age has doubled.
THERE
Deaths From Carcinoma
of Cervix (England and Wales) By
Age and Year
CONCLUSIONS
1. The absolute number of young women with abnormal smears is increasing, although the proportion with abnormal smears has not risen. A relative increase
The increase in deaths in younger women is widely held to be associated with the early onset of sexual activity in the young and with the increased use of non-bar-
1032 rier contraceptives, particularly the contraceptive pill and intrauterine devices which offer no protection against the transmissible agent, be it virus or spermatozoa, thought to be responsible for the disease. The North Western Region has developed the most advanced screening programme in the U.K. for the detection of pre-cancerous lesions of the cervix. Computerisation of the records system has also enabled us to analyse the large number of cyto-tests performed in this region in a way that would be impossible otherwise. In 1965, a total of 5171 tests were examined; in 1977 this number had reached 188 047, and the records now contain a total of 1476 865 tests from 696 768 women. Whilst this is a gratifying achievement, we are always conscious of the fact that, according to the 1971 census, we have some 1.5million women over the age of 20 years in the region. We have been especially successful in involving the general practitioners (G.P.s) in the screening programme.
The pre-invasive phase of carcinoma of the cervix may be shorter in younger women, leading more quickly to an aggressive invasive tumour, which is less likely to be prevented by routine screening, unless the interval between tests is short; or we may tend to test women at low risk. Indeed both of these factors may be operating. Conversely, in older women, we may be more effective in screening the high-risk segment. The pre-invasive stage may be longer, invasive growth a less frequent and less aggressive sequel. The Department of Health and Social Security encourages, by payments to general practitioners, the screening of older women. This conflicts with the findings in this paper. It is time to take note of the changes in sexual activity and contraceptive practice in younger women in the U.K. Since these women are not likely to abandon the contraceptive pill and return to the diaphragm and condom, the detection of pre-cancerous conditions of the cervix must be ensured by widespread and frequent cyto-testing.
Occupational Until recently, we were able to recall women for testing every three years, but financial stringency has compelled us to change to a five-yearly recall, in line with the national scheme. We believe that the increased frequency of testing contributed to an improvement in the incidence of, and mortality from, carcinoma of the cervix in the North Western Region which exceeds the improvement in the country as a whole. Data from the Registrar General show an improvement of 11-8% in deaths from carcinoma of the cervix in England and Wales, while the improvement in the North-Western Region over the same period of time was 15.2%. There was a progressive reduction in the numbers of women presenting for the first time to the Christie Hospital with clinical cervical cancer:
Despite the fact that in the North Western Region (and probably in England and Wales generally) the largest increase in cyto-testing occurred in women under 35 years of age, deaths in this age-group have increased. Also the rate of detection of pre-cancerous conditions of the cervix did not increase in this group from 1970 to 1977, although there was a significant increase in older women.
Positive
Cyto-test Rates (1970 and 1977) (North
Western
Region)
It seems that, although we are testing increasingly large numbers of young women, such screening is relatively ineffective in detecting pre-cancerous lesions leading to the prevention of death from invasive carcinoma.
Health
OCCUPATIONAL EXPOSURE TO IONISING RADIATION THE RISK IN PERSPECTIVE*
J. A. BONNELL
G. HARTE
Nuclear Health and Safety Department and Berkeley Nuclear Laboratories, Central Electricity Generating Board, London
IN its latest recommendations the International Commission on Radiological Protection has formulated its new protection philosophy. Having classified the biological effects of radiation exposure as "stochastic" and "non-stochastic", the document states that the aim of radiation protection should be to prevent non-stochastic effects (such as cataract of the lens and non-malignant skin damage for which the severity of the effect varies with dose) and to limit the probability of stochastic effects to an acceptable level. The stochastic effects of irradiation are those for which the probability of occurrence of the effect is a function of dose. Carcinogenesis-the chief somatic effect of irradiation at low doses-is stochastic, as is the induction of genetic
damage. In pursuance of its aims, the Commission has moved away from the concept of limiting the dose to a critical organ, and now recommends a protection procedure which takes account of the total risk attributable to the exposure of all irradiated tissues in the body. A protection system based on risk limitation involves the assignment of a risk per unit dose to the tissues of the body susceptible to the induction of stochastic effects, and table i lists the risk factors put forward by the Commission. These risk factors may be used in conjunction with postulated exposure regimens to estimate the risk to an average member of the working population or of the general public arising from the operation of nuclear power plants. * Based on a paper presented at an international symposium on the late biological effects of radiation held in Vienna on March 13-17, 1978, and published in this form by courtesy of the Editor of the Proceedings of the Conference.
