Risk of head-and-neck cancer following a diagnosis of severe cervical intraepithelial neoplasia: a nationwide population-based cohort study in Denmark.

OBJECTIVE: Women with a history of cervical intraepithelial neoplasia grade 3 including adenocarcinoma in situ (CIN3/AIS) may be more prone to develop cancers of the ano-genital region and head-and-neck cancers. The current literature is, however, limited. METHODS: We established a nationwide cohort of approximately 2,500,000 Danish women born in 1918-1990. By linking the cohort to population-based health registries, we obtained information on CIN3/AIS, cancer, migration, death, education, and smoking. Cox proportional hazards models were used to estimate hazard ratios (HRs) and confidence intervals (CIs) for the association between CIN3/AIS and risk of head-and-neck squamous cell carcinoma (HNSCC). HRs were presented for any HNSCC and for four subgroups categorized by their anticipated degree of association with human papillomavirus (HPV). RESULTS: A history of CIN3/AIS was significantly associated with an increased overall relative risk of HNSCC after adjustment for year of birth, attained age, and length of education. The risk was especially high for sites anticipated to be strongly associated with HPV (e.g. base of tongue, tonsils) (HR, 2.49; 95% CI, 1.84-3.36). Lower risks were found for sites anticipated to be not or weakly associated with HPV (e.g. nasal cavity, middle ear, sinuses) (HR, 1.29; 95% CI, 0.61-2.76). CONCLUSION: Women with a history of CIN3/AIS have a significantly higher risk of HNSCC than women without such a history. The increased relative risk persisted for at least 20years after the CIN3/AIS diagnosis. Women with CIN3/AIS may be more susceptible to the consequences of HPV and/or may have higher risk behavior, such as smoking.

Mental disorders in childhood and young adulthood among children born to women with fertility problems.

STUDY QUESTION: Is the risk of hospital admission or outpatient contact for mental disorders increased in children born to women with fertility problems compared with children born to women without fertility problems? SUMMARY ANSWER: We found an increased risk of hospital admission or outpatient contact for mental disorders in children born to women with fertility problems. WHAT IS KNOWN ALREADY: Few studies have investigated the risk of mental disorders in children born after fertility treatment and although some studies have pointed to an increased risk, others found no association. The inconsistent results may be due to methodological constraints in many previous studies, including small sample size and short follow-up, resulting in imprecise risk estimates and lack of information on risk patterns of mental disorders in adulthood. STUDY DESIGN, SIZE, DURATION: This nationwide retrospective register-based cohort study included all 2 412 721 children born in Denmark between 1969 and 2006. All children were followed from date of birth until date of hospital contact for a mental disorder, date of emigration, date of death or 31 December 2009, whichever occurred first. PARTICIPANTS/MATERIALS, SETTING, METHODS: Information concerning maternal fertility status for all children in the cohort was obtained by linkage to the Danish Infertility Cohort, which contains data on nearly all women with fertility problems in Denmark since 1963. A total of 124 269 (5%) children were born to women with fertility problems and 2 288 452 (95%) to women without fertility problems. To identify children hospitalized for a mental disorder, the cohort was linked to the Danish Psychiatric Central Research Registry. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between maternal fertility status and the risk of hospital admission or outpatient contact for various groups of mental disorders, including any mental disorder and all 11 main discharge diagnostic groups, classified according to the International Classification of Diseases, version 10. MAIN RESULTS AND THE ROLE OF CHANCE: During a mean follow-up period of 21 years (range, 0-40 years), 168 686 (7%) children were admitted to hospital or had an outpatient contact for a mental disorder. Children born to women with fertility problems had a significantly higher risk of any mental disorder (HR 1.23; 95% CI 1.20-1.26) and for most of the 11 main discharge groups, including schizophrenia (HR 1.16; 95% CI 1.07-1.27), mood (affective) disorders (HR 1.21; 95% CI 1.15-1.28) and disorders of psychological development (HR 1.15; 95% CI 1.09-1.21) as well as the subgroup of attention-deficit/hyperactivity disorders (HR 1.36; 95% CI 1.29-1.45) compared with children born to women without fertility problems. The risk estimates did not change markedly when analyses were performed separately for mental disorders diagnosed during childhood (0-19 years) and in young adulthood (20-40 years). LIMITATIONS, REASON FOR CAUTION: The true risk of mental disorders may be somewhat underestimated, as only severe disorders requiring hospital admission or outpatient contact were considered as events. Furthermore, we could not determine whether the increased risks observed were due to factors related to the underlying infertility or to fertility treatment procedures. WIDER IMPLICATIONS OF THE FINDINGS: This is the first report on mental disorders in adulthood among children born to women with fertility problems. Furthermore, we have assessed the risk of several severe mental disorders not previously studied (e.g. neurotic, stress-related and somatoform disorders and disorders of adult personality and behaviour). These important findings should be investigated further in large epidemiological studies designed to differentiate between factors related to fertility treatment and to the underlying infertility. STUDY FUNDING/COMPETING INTERESTS: The study was supported by internal funding from the Unit of Virus, Lifestyle and Genes at the Danish Cancer Society Research Center. All authors report no conflicts of interest.