Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study
Abstract Introduction The incidence of cancer during pregnancy and within first year post‐delivery, ie pregnancy‐associated cancer (PAC), is increasing in many countries, but little is known about risk factors for these trends. This study quantified incidence of PAC by trimesters and post‐delivery p...
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| Format: | Article |
| Language: | English |
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Wiley
2024-04-01
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| Series: | Acta Obstetricia et Gynecologica Scandinavica |
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| Online Access: | https://doi.org/10.1111/aogs.14677 |
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| author | Frida E. Lundberg Hanne Stensheim Gustav J. Ullenhag Hanna Milerad Sahlgren Kristina Lindemann Irma Fredriksson Anna L. V. Johansson |
| author_facet | Frida E. Lundberg Hanne Stensheim Gustav J. Ullenhag Hanna Milerad Sahlgren Kristina Lindemann Irma Fredriksson Anna L. V. Johansson |
| author_sort | Frida E. Lundberg |
| collection | DOAJ |
| description | Abstract Introduction The incidence of cancer during pregnancy and within first year post‐delivery, ie pregnancy‐associated cancer (PAC), is increasing in many countries, but little is known about risk factors for these trends. This study quantified incidence of PAC by trimesters and post‐delivery periods, and assessed the role of maternal age, parity, immigrant status, education, smoking and body mass index for the risk and incidence trends of PAC. Material and methods We used data from the national birth and cancer registers in Sweden during 1973–2017 to define a register‐based cohort of women aged 15–44 years. Incidence rates of PAC during pregnancy and up to 1 year post‐delivery were calculated per 100 000 deliveries per year. Poisson regression with multiple imputation estimated incidence rate ratios with 95% confidence intervals adjusted by year, age, previous parity, immigrant status, education, smoking and BMI during 1990–2017, when information on risk factors was available. Results Among 4 557 284 deliveries, a total of 1274 (during pregnancy) and 3355 (within 1 year post‐delivery) cases of PAC were diagnosed, with around 50 cases/year diagnosed during pregnancy and 110 cases/year during the first year post‐delivery in the latest period 2015–2017. The most common cancer types during pregnancy were malignant melanoma, breast and cervical cancer, together accounting for 57% of cases during pregnancy and 53% during the first year post‐delivery. The numbers of PAC were lower during pregnancy than during post‐delivery for all tumor types with lowest numbers during first trimester. The PAC incidence rates increased over calendar time. High maternal age at diagnosis, smoking, nulliparity and non‐immigrant background were associated with significantly higher risks of PAC. The increasing PAC incidence was in part explained by higher maternal age over time, but not by the other factors. Conclusions High maternal age is the strongest risk factor for PAC. We show for the first time that smoking, nulliparity and non‐immigrant background are also contributing risk factors for PAC. However, only high maternal age contributed significantly to the increasing incidence. Further studies on other potential risk factors for PAC are warranted, since our results indicate that age on its own does not fully explain the increase. |
| format | Article |
| id | doaj-art-5dac4144371b4ea39dbf9b5c7f3f27dd |
| institution | Kabale University |
| issn | 0001-6349 1600-0412 |
| language | English |
| publishDate | 2024-04-01 |
| publisher | Wiley |
| record_format | Article |
| series | Acta Obstetricia et Gynecologica Scandinavica |
| spelling | doaj-art-5dac4144371b4ea39dbf9b5c7f3f27dd2025-08-20T03:30:56ZengWileyActa Obstetricia et Gynecologica Scandinavica0001-63491600-04122024-04-01103466968310.1111/aogs.14677Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based studyFrida E. Lundberg0Hanne Stensheim1Gustav J. Ullenhag2Hanna Milerad Sahlgren3Kristina Lindemann4Irma Fredriksson5Anna L. V. Johansson6Department of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm SwedenCancer Registry of Norway Oslo NorwayDepartment of Oncology Uppsala University Hospital Uppsala SwedenDepartment of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm SwedenDepartment of Gynecological Oncology Oslo University Hospital Oslo NorwayDepartment of Molecular Medicine and Surgery Karolinska Institutet Stockholm SwedenDepartment of Medical Epidemiology and Biostatistics Karolinska Institutet Stockholm SwedenAbstract Introduction The incidence of cancer during pregnancy and within first year post‐delivery, ie pregnancy‐associated cancer (PAC), is increasing in many countries, but little is known about risk factors for these trends. This study quantified incidence of PAC by trimesters and post‐delivery periods, and assessed the role of maternal age, parity, immigrant status, education, smoking and body mass index for the risk and incidence trends of PAC. Material and methods We used data from the national birth and cancer registers in Sweden during 1973–2017 to define a register‐based cohort of women aged 15–44 years. Incidence rates of PAC during pregnancy and up to 1 year post‐delivery were calculated per 100 000 deliveries per year. Poisson regression with multiple imputation estimated incidence rate ratios with 95% confidence intervals adjusted by year, age, previous parity, immigrant status, education, smoking and BMI during 1990–2017, when information on risk factors was available. Results Among 4 557 284 deliveries, a total of 1274 (during pregnancy) and 3355 (within 1 year post‐delivery) cases of PAC were diagnosed, with around 50 cases/year diagnosed during pregnancy and 110 cases/year during the first year post‐delivery in the latest period 2015–2017. The most common cancer types during pregnancy were malignant melanoma, breast and cervical cancer, together accounting for 57% of cases during pregnancy and 53% during the first year post‐delivery. The numbers of PAC were lower during pregnancy than during post‐delivery for all tumor types with lowest numbers during first trimester. The PAC incidence rates increased over calendar time. High maternal age at diagnosis, smoking, nulliparity and non‐immigrant background were associated with significantly higher risks of PAC. The increasing PAC incidence was in part explained by higher maternal age over time, but not by the other factors. Conclusions High maternal age is the strongest risk factor for PAC. We show for the first time that smoking, nulliparity and non‐immigrant background are also contributing risk factors for PAC. However, only high maternal age contributed significantly to the increasing incidence. Further studies on other potential risk factors for PAC are warranted, since our results indicate that age on its own does not fully explain the increase.https://doi.org/10.1111/aogs.14677breast cancercervical cancerincidencemalignant melanomapregnancypregnancy‐associated cancer |
| spellingShingle | Frida E. Lundberg Hanne Stensheim Gustav J. Ullenhag Hanna Milerad Sahlgren Kristina Lindemann Irma Fredriksson Anna L. V. Johansson Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study Acta Obstetricia et Gynecologica Scandinavica breast cancer cervical cancer incidence malignant melanoma pregnancy pregnancy‐associated cancer |
| title | Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study |
| title_full | Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study |
| title_fullStr | Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study |
| title_full_unstemmed | Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study |
| title_short | Risk factors for the increasing incidence of pregnancy‐associated cancer in Sweden – a population‐based study |
| title_sort | risk factors for the increasing incidence of pregnancy associated cancer in sweden a population based study |
| topic | breast cancer cervical cancer incidence malignant melanoma pregnancy pregnancy‐associated cancer |
| url | https://doi.org/10.1111/aogs.14677 |
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