To evaluate the association between urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) level—a marker of oxidative stress—and the incidence of preterm births (PTBs).

Prospective cohort study.

The Japan Environment and Children’s Study (JECS).

Data from 92 715 women with singleton pregnancies at and after 22 weeks of gestation who were enrolled in the JECS, a nationwide birth cohort study, between 2011 and 2014 were analysed. U8-OHdG levels were assessed once in the second/third trimester using liquid chromatography–tandem mass spectrometry. Participants were categorised into the following three or five groups: low (

Adjusted OR (aOR) for PTB before 37 and 34 weeks of gestation were calculated using a multivariable logistic regression model while adjusting for confounding factors; the moderate or lowest U8-OHdG group was used as the reference, respectively.

The aORs for PTB before 37 weeks of gestation in the high U8-OHdG group were 1.13 (95% CI 1.05 to 1.22) and 1.13 (95% CI 1.04 to 1.23) after stratification. The aOR for PTB before 37 weeks in the fourth group was 0.90 (95% CI 0.81 to 0.99). After stratification, the aORs for PTB before 37 and 34 weeks in the fifth group were 1.15 (95% CI 1.03 to 1.29) and 1.46 (95% CI 1.08 to 1.97), respectively.

High U8-OHdG levels were associated with increased PTB incidence, especially in participants without representative causes for artificial PTB. Our results can help identify the mechanisms leading to PTB, considering the variable aetiologies of this condition; further validation is needed to clarify clinical impacts.

Since May 2019, comprehensive genomic profiling (CGP) has been covered by Japan’s health insurance system for patients with solid tumours that have progressed on standard chemotherapy, rare tumours or tumours of unknown primary origin. Although CGP has the potential to identify actionable mutations that can guide the selection of genomically matched therapies for patients with advanced cancer and limited treatment options, less than 10% of patients benefit from CGP testing, which may have a negative impact on patients’ mental status. The aim of this study is to investigate the prevalence of psychological distress and associated factors among patients with advanced cancer who are undergoing CGP testing across Japan.

This multicentre, prospective cohort study will enrol a total of 700 patients with advanced cancer undergoing CGP testing. Participants will be asked to complete questionnaires at three timepoints: at the time of consenting to CGP testing (T1), at the time of receiving the CGP results (T2; 2–3 months after T1) and 4–5 months after T2 (T3). Primary outcome is the prevalence of depression as measured by the Patient Health Questionnaire-9 at the three timepoints. Secondary outcomes are the prevalence of anxiety and Quality of Life Score. Associated factors with psychological distress will also be examined, including knowledge about CGP, attitudes, values and preferences towards CGP, satisfaction with oncologists’ communication and patient characteristics as well as medical information including CGP test results and genomically matched therapies if provided. The prevalence of depression and anxiety will be estimated using the unadjusted raw rates observed in the total sample. Longitudinal changes in measures will be explored by calculating differences between the timepoints. Multivariate associations between variables will be examined using multiple or logistic regression analysis depending on the outcomes to adjust for confounders and to identify outcome predictors.

This study was approved by the Institutional Review Board of the National Cancer Center Japan on 5 January 2023 (ID: 2022-228). Study findings will be disseminated through peer-reviewed journals and conference presentations.

The study is currently recruiting participants and the enrolment period will end on 31 March 2025, with an expected follow-up date of 31 March 2026.

UMIN000049964.