Risk Of Cancer Incidence Research Articles

Recent and projected incidence trends and risk of anal cancer among people with HIV in North America.

Anal cancer risk is elevated among people with HIV. Recent anal cancer incidence patterns among people with HIV in the United States and Canada remain unclear. It is unknown how the incidence patterns may evolve. Using data from the North American AIDS Cohort Collaboration on Research and Design, we investigated absolute anal cancer incidence and incidence trends nationally in the United States and Canada and in different US regions. We further estimated relative risk compared with people without HIV, relative risk among various subgroups, and projected future anal cancer burden among American people with HIV. Between 2001 and 2016 in the United States, age-standardized anal cancer incidence declined 2.2% per year (95% confidence interval = ‒4.4% to ‒0.1%), particularly in the Western region (‒3.8% per year, 95% confidence interval = ‒6.5% to ‒0.9%). In Canada, incidence remained stable. Considerable geographic variation in risk was observed by US regions (eg, more than 4-fold risk in the Midwest and Southeast compared with the Northeast among men who have sex with men who have HIV). Anal cancer risk increased with a decrease in nadir CD4 cell count and was elevated among those individuals with opportunistic illnesses. Anal cancer burden among American people with HIV is expected to decrease through 2035, but more than 70% of cases will continue to occur in men who have sex with men who have HIV and in people with AIDS. Geographic variation in anal cancer risk and trends may reflect underlying differences in screening practices and HIV epidemic. Men who have sex with men who have HIV andpeople with prior AIDS diagnoses will continue to bear the highest anal cancer burden, highlighting the importance of precision prevention.

Implication of metabolically healthy obesity on the risk of incident pancreatic cancer: a nationwide population-based cohort study

Implication of metabolically healthy obesity on the risk of incident pancreatic cancer: a nationwide population-based cohort study

Trend analysis and age-period-cohort effects on morbidity and mortality of liver cancer from 2010 to 2020 in Guangzhou, China.

Liver cancer is one of the most common malignant gastrointestinal tumors worldwide. This study intends to provide insight into the epidemiological characteristics and development trends of liver cancer incidence and mortality from 2010 to 2020 in Guangzhou, China. Data were collected from the Cancer Registry and Reporting Office of Guangzhou Center for Disease Control and Prevention. Cross-sectional study, Joinpoint regression (JPR) model, and Age-Period-Cohort (APC) model were conducted to analyze the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) trend of liver cancer among the entire study period. The age-standardized incidence and mortality of liver cancer in Guangzhou showed an overall decreasing trend. The disparity in risk of morbidity and mortality between the two sexes for liver cancer is increasing. The cohort effect was the most significant among those born in 1965~1969, and the risk of liver cancer incidence and mortality in the total population increased and then decreased with the birth cohort. Compared with the birth cohort born in 1950~1954 (the reference cohort), the risk of liver cancer incidence and mortality in the males born in 1995~1999 decreased by 32% and 41%, respectively, while the risk in the females decreased by 31% and 32%, respectively. The early detection, prevention, clinical diagnosis, and treatment of liver cancer in Guangzhou have made remarkable achievements in recent years. However, the risk of liver cancer in the elderly and the middle-aged males is still at a high level. Therefore, the publicity of knowledge related to the prevention and treatment of liver cancer among the relevant population groups should be actively carried out to enhance the rate of early diagnosis and treatment of liver cancer and to advocate a healthier lifestyle.

Abstract PO3-09-03: Dysbiosis of gut microbiota in patients with breast cancer

Abstract [Background] The effects of gut microbiome on various diseases have become widely known, and many studies reported that there was a correlation between the change of gut microbiota, that is dysbiosis, and the progression of digestive tract cancer. In addition, it is well-known that gut microbiota was correlated to the efficacy of immune checkpoint inhibitors for multiple types of cancer. However, the significance of gut microbiota in patients with breast cancer still remains unclear. The aim of this study is to analyze the gut microbiota in patients with breast cancer, compared with healthy women. [Subjects and Methods] We used the pre-treatment feces of 79 patients with primary breast cancer who received treatment at our facility and performed metagenome analysis of the V3-4 region of 16S rDNA. We also analyzed the breast cancer patients' microbiota with QIIME2 analysis method, compared to randomly selected 100 women aged 30-77 years from NIBIOHN's public data . We also assessed the characteristics of the gut microbiota of breast cancer patients by subtypes and its relationship with clinical and pathological factors. [Results] In Japanese gut microbiota, the Firmicutes and Bacteroidetes phyla make up the majority, but Firmicutes was the most common bacterial phylum in 52% of the public cohort, whereas 96.2% (76/79) of the breast cancer patients’ group (BC) showed a significantly higher proportion (p< 0.0001). In addition, ANCOM analysis revealed that the relative bacterial amounts of the Firmicutes, Bacteroidetes, and Proteobacteria phyla were significantly decreased in BC compared to the public cohort (PC), and at the bacterial genus level, the Feacalibacterium genus was significantly decreased in BC. Furthermore, the percentage of Fusobacteria phylum, which is a well-known oral bacteria that exacerbates digestive tract cancer, was 49.3% in BC, compared to 35% in PC (p=0.04). Among BC, the relative frequency of Fusobacteria phylum was significantly higher in the HER2-negative group than in the HER2-positive group (p< 0.0001). In BC, both alpha diversity (p< 0.0001) and beta diversity (p=0.001) were significantly lower than in PC. [Conclusion] An increase in the Firmicutes phylum is known to be associated with obesity, and also likely to affect the incidence risk of breast cancer. The results suggest that the Fusobacteria phylum and Feacalibacterium genus may be risk or preventive factors for breast cancer. Dysbiosis of gut microbiota is suggested to be associated with various diseases, and in this study the decrease in bacterial amount and diversity was observed in BC compared to PC, which may affect the onset and progression of breast cancer. Citation Format: Mai Yamada, Takafumi Morisaki, Yo Sato, Kimihisa Mizoguchi, Yuka Takao, Yurina Ochiai, Yoshiki Ootubo, Saori Hayashi, Masafumi Nakamura, Makoto Kubo. Dysbiosis of gut microbiota in patients with breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-09-03.

Impaired lung function and lung cancer risk in 461 183 healthy individuals: a cohort study

BackgroundIt has been known that smoking and various lung diseases including lung cancer can cause lung function impairment. However, the impact of different types of lung function impairments, such as...

Safety of Immunosuppression in a Prospective Cohort of Inflammatory Bowel Disease Patients With a HIstoRy of CancEr: SAPPHIRE Registry

Background and AimsIn patients with inflammatory bowel disease (IBD) and a history of cancer, retrospective studies suggest that exposure to immunosuppressive agents does not increase the risk of incident (recurrent or new) cancer compared to unexposed patients. SAPPHIRE is a prospective registry aimed at addressing this issue. MethodsSince 2016, patients with IBD and confirmed index cancer prior to enrollment were followed annually. Patients receiving chemotherapy or radiation at enrollment, or recurrent cancer within five years were excluded. Primary outcome was development of incident cancer related to exposure to immunosuppressive medications. ResultsAmong 305 patients (47% male, 88% white), median age at IBD diagnosis and cancer were 32 and 52 years, respectively. Index cancers were solid organ (46%), dermatologic (32%), gastrointestinal (13%), and hematologic (9%). During median follow-up of 4.8 years, 210 (69%) were exposed to immunosuppressive therapy and 46 (15%) developed incident cancers (25 new, 21 recurrent). In unadjusted analysis, the crude rate of incident cancer in unexposed patients was 2.58/100 person-years versus 4.78/100 PY (relative risk 1.85, 95% CI 0.92-3.73) for immunosuppression exposed patients. In a proportional hazards model adjusting for sex, smoking history, age and stage at index malignancy, and non-melanoma skin cancer, no significant association was found between receipt of immunosuppression and incident cancer (adjusted hazard ratio, aHR, 1.41, 95% CI: 0.69-2.90), or with any major drug class. ConclusionIn this interim analysis of patients with IBD and a history of cancer, despite numerically elevated aHRs, we did not find a statistically significant association between subsequent exposure to immunosuppressive therapies and development of incident cancers.

Sodium-glucose cotransporter-2 inhibitors and the risk of lung cancer among patients with type 2 diabetes.

We sought to determine whether the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitors is associated with a decreased risk of incident lung cancers among patients with type 2 diabetes. We assembled a new-user, active comparator cohort of SGLT-2 inhibitor and dipeptidyl peptidase-4 (DPP-4) inhibitor users using the United Kingdom Clinical Practice Research Datalink. We fit Cox proportional hazards models with propensity score fine stratification weighting to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident lung cancer. Crude incidence rates were 0.94 per 1000 person-years among 69 675 SGLT-2 inhibitor users followed for a median of 2.4years and 1.45 per 1000 person-years among 151 495 DPP-4 inhibitor users followed for a median of 3.7years. No reduced short-term risk of lung cancer was observed among SGLT-2 inhibitor users after weighting (HR 0.96, 95% CI 0.77-1.21). Further research with a longer follow-up period may be warranted.

Associations of combined phenotypic aging and genetic risk with incident cancer: A prospective cohort study.

Age is the most important risk factor for cancer, but aging rates are heterogeneous across individuals. We explored a new measure of aging-Phenotypic Age (PhenoAge)-in the risk prediction of site-specific and overall cancer. Using Cox regression models, we examined the association of Phenotypic Age Acceleration (PhenoAgeAccel) with cancer incidence by genetic risk group among 374,463 participants from the UK Biobank. We generated PhenoAge using chronological age and nine biomarkers, PhenoAgeAccel after subtracting the effect of chronological age by regression residual, and an incidence-weighted overall cancer polygenic risk score (CPRS) based on 20 cancer site-specific polygenic risk scores (PRSs). Compared with biologically younger participants, those older had a significantly higher risk of overall cancer, with hazard ratios (HRs) of 1.22 (95% confidence interval, 1.18-1.27) in men, and 1.26 (1.22-1.31) in women, respectively. A joint effect of genetic risk and PhenoAgeAccel was observed on overall cancer risk, with HRs of 2.29 (2.10-2.51) for men and 1.94 (1.78-2.11) for women with high genetic risk and older PhenoAge compared with those with low genetic risk and younger PhenoAge. PhenoAgeAccel was negatively associated with the number of healthy lifestyle factors (Beta = -1.01 in men, p<0.001; Beta = -0.98 in women, p<0.001). Within and across genetic risk groups, older PhenoAge was consistently related to an increased risk of incident cancer with adjustment for chronological age and the aging process could be retarded by adherence to a healthy lifestyle. This work was supported by the National Natural Science Foundation of China (82230110, 82125033, 82388102 to GJ; 82273714 to MZ); and the Excellent Youth Foundation of Jiangsu Province (BK20220100 to MZ).

Associations of combined phenotypic aging and genetic risk with incident cancer: A prospective cohort study

Background:Age is the most important risk factor for cancer, but aging rates are heterogeneous across individuals. We explored a new measure of aging-Phenotypic Age (PhenoAge)-in the risk prediction of site-specific and overall cancer.Methods:Using Cox regression models, we examined the association of Phenotypic Age Acceleration (PhenoAgeAccel) with cancer incidence by genetic risk group among 374,463 participants from the UK Biobank. We generated PhenoAge using chronological age and nine biomarkers, PhenoAgeAccel after subtracting the effect of chronological age by regression residual, and an incidence-weighted overall cancer polygenic risk score (CPRS) based on 20 cancer site-specific polygenic risk scores (PRSs).Results:Compared with biologically younger participants, those older had a significantly higher risk of overall cancer, with hazard ratios (HRs) of 1.22 (95% confidence interval, 1.18–1.27) in men, and 1.26 (1.22–1.31) in women, respectively. A joint effect of genetic risk and PhenoAgeAccel was observed on overall cancer risk, with HRs of 2.29 (2.10–2.51) for men and 1.94 (1.78–2.11) for women with high genetic risk and older PhenoAge compared with those with low genetic risk and younger PhenoAge. PhenoAgeAccel was negatively associated with the number of healthy lifestyle factors (Beta = –1.01 in men, p&lt;0.001; Beta = –0.98 in women, p&lt;0.001).Conclusions:Within and across genetic risk groups, older PhenoAge was consistently related to an increased risk of incident cancer with adjustment for chronological age and the aging process could be retarded by adherence to a healthy lifestyle.Funding:This work was supported by the National Natural Science Foundation of China (82230110, 82125033, 82388102 to GJ; 82273714 to MZ); and the Excellent Youth Foundation of Jiangsu Province (BK20220100 to MZ).

Incident Cancer Risk in Patients with Incident Type 2 Diabetes Mellitus in Hungary (Part 1).

(1) Background: Patients with type 2 diabetes mellitus (T2DM) are at higher risk of cancer but how these two diseases associate is still debated. The goal of this study was the assessment of the overall incidence of cancer among patients with newly diagnosed T2DM in Hungary. (2) Methods: A nationwide, retrospective, longitudinal study was performed using a Hungarian database. After exclusion of cases of age < 18 years, with gestational diabetes, with polycystic ovary syndrome, and with type 1 and prevalent type 2 diabetes mellitus, the incident T2DM (approx. 50,000 cases yearly) and for comparison, the diabetes-free Hungarian adult population (approx. 7,000,000 cases yearly) was included in the study. The primary endpoints were the overall and site-specific incidence and annual percentage change of the incidence of cancer in both populations. (3) Results: The overall incidence of cancer in patients amounted to 29.4/1000 and 6.6/1000 with or without T2DM, respectively, and the OR (95%CI) of cancer of the T2DM group was 4.32 (4.14-4.53), p < 0.0001. The risk of having cancer was age dependent. The incidence of cancer was declining in the non-diabetic but was unchanged in the T2DM population. The average lag time of diagnosing cancer after the detection of T2DM was 3.86 months. (4) Conclusions: Incident T2DM is associated with a significantly higher overall risk of incident cancer, with a reverse correlation of age. Newly registered T2DM patients were suggested to be screened for cancer within 6 months.

Blood-Based Epigenetic Age Acceleration and Incident Colorectal Cancer Risk: Findings from a Population-Based Case-Control Study.

This study investigates the association between epigenetic age acceleration (EAA) derived from DNA methylation and the risk of incident colorectal cancer (CRC). We utilized data from a random population sample of 9,360 individuals (men and women, aged 45-69) from the HAPIEE Study who had been followed up for 16 years. A nested case-control design yielded 35 incident CRC cases and 354 matched controls. Six baseline epigenetic age (EA) measures (Horvath, Hannum, PhenoAge, Skin and Blood (SB), BLUP, and Elastic Net (EN)) were calculated along with their respective EAAs. After adjustment, the odds ratios (ORs) for CRC risk per decile increase in EAA ranged from 1.20 (95% CI: 1.04-1.39) to 1.44 (95% CI: 1.21-1.76) for the Horvath, Hannum, PhenoAge, and BLUP measures. Conversely, the SB and EN EAA measures showed borderline inverse associations with ORs of 0.86-0.87 (95% CI: 0.76-0.99). Tertile analysis reinforced a positive association between CRC risk and four EAA measures (Horvath, Hannum, PhenoAge, and BLUP) and a modest inverse relationship with EN EAA. Our findings from a prospective population-based-case-control study indicate a direct association between incident CRC and four markers of accelerated baseline epigenetic age. In contrast, two markers showed a negative association or no association. These results warrant further exploration in larger cohorts and may have implications for CRC risk assessment and prevention.

CORRELATION OF ADOLESCENT KNOWLEDGE ABOUT FREE SEX PRACTICES WITH THE RISK OF CERVICAL CANCER ON THE MOTIVATION OF HPV VACCINATION AT JUNIOR HIGH SCHOOL 6 SURABAYA

Background: Cervical cancer had the second position as the leading cause of cancer towards woman in worldwide. The prevalence of cervical cancer in Indonesia reaches 23,4 cases from 100.000 population (Kemenkes RI, 2019). To enhance awareness and knowledge about HPV vaccination and cervical cancer, it is imperative to disseminate information through early health promotion regarding cervical cancer prevention, including HPV vaccination, and avoiding behaviors that may elevate the risk of cervical cancer, such as engaging in unprotected sexual activities. The aim of this study is to determine the correlation between adolescents' knowledge of "Free Sexual Practices with Cervical Cancer Incidence Risk" towards motivation for HPV vaccination at 6 Junior High School Surabaya. Method: The quantitative cross-sectional approach involved 304 students from grades 7, 8, and 9, selected through stratified sampling and was analyzed using the Spearman analysis test. Results: The majority (83.1%) of adolescents in grades 7, 8, and 9 demonstrated good knowledge (83.1%) regarding free sexual practices with the risk of cervical cancer incidence. A considerable number of adolescents (29.9%) in grades 7, 8, and 9 showed a moderate level of motivation. There is a significant correlation between the knowledge level regarding cervical cancer and the risk of cervical cancer incidence concerning motivation for HPV vaccination, with a p-value of 0.000 (p &lt; 0.05). Conclusion: There is a correlation between the knowledge level regarding cervical cancer and the risk of cervical cancer incidence concerning motivation for HPV vaccination at 6 Junior High School Surabaya.

Family history and gastric cancer incidence and mortality in Asia: a pooled analysis of more than half a million participants

BackgroundThe family history of gastric cancer holds important implications for cancer surveillance and prevention, yet existing evidence predominantly comes from case–control studies. We aimed to investigate the association between family history of gastric cancer and gastric cancer risk overall and by various subtypes in Asians in a prospective study.MethodsWe included 12 prospective cohorts with 550,508 participants in the Asia Cohort Consortium. Cox proportional hazard regression was used to estimate study-specific adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between family history of gastric cancer and gastric cancer incidence and mortality, then pooled using random-effects meta-analyses. Stratified analyses were performed for the anatomical subsites and histological subtypes.ResultsDuring the mean follow-up of 15.6 years, 2258 incident gastric cancers and 5194 gastric cancer deaths occurred. The risk of incident gastric cancer was higher in individuals with a family history of gastric cancer (HR 1.44, 95% CI 1.32–1.58), similarly in males (1.44, 1.31–1.59) and females (1.45, 1.23–1.70). Family history of gastric cancer was associated with both cardia (HR 1.26, 95% CI 1.00–1.60) and non-cardia subsites (1.49, 1.35–1.65), and with intestinal- (1.48, 1.30–1.70) and diffuse-type (1.59, 1.35–1.87) gastric cancer incidence. Positive associations were also found for gastric cancer mortality (HR 1.30, 95% CI 1.19–1.41).ConclusionsIn this largest prospective study to date on family history and gastric cancer, a familial background of gastric cancer increased the risk of gastric cancer in the Asian population. Targeted education, screening, and intervention in these high-risk groups may reduce the burden of gastric cancer.

Paediatric cancer risks associated with chest computed tomography (CT) scans: comparison of routine chest and COVID-19 diagnosis CT protocols

The aim of this study is to compare the radiation dose and cancer incidence risk associated with two chest Computed Tomography (CT) protocols: routine chest CT (RC-CT) and COVID-19 Diagnosis CT protocol (CD-CT). The study included 254 pediatric patients divided into three age groups: G1 (&lt;5), G2 (5–&lt;10), and G3 (10–15). The effective diameter, volumetric CT dose index (CTDIvol), dose length product (DLP), size specific dose estimate (SSDE), organ doses, and cancer incidence risk were calculated for the two protocols. Organ doses (mSv) and effective dose (mSv) were estimated using the National Cancer Institute dosimetry system for CT (NCICT) software. Estimation of cancer incidence risks were conducted according to the Biological Effects of Ionizing Radiation (BEIR) VII report. The oldest group (G3) in two protocols exhibited the greatest values for CTDIvol, DLP, effective dose and SSDE. The results showed that CD-CT protocol resulted in statistically significant (p &lt; 0.05) lower organ doses and cancer incidence risk. The cancer incidence risk for both protocols did not exceed the reference levels reported in literature surveys on pediatric CT chest radiation dose for all age groups. It can be concluded that the choice of CT protocol can significantly impact the radiation dose received by pediatric patients during CT imaging, highlighting the importance of carefully selecting the appropriate protocol to minimize radiation exposure.

Targeted-BEHRT: Deep Learning for Observational Causal Inference on Longitudinal Electronic Health Records.

Observational causal inference is useful for decision-making in medicine when randomized clinical trials (RCTs) are infeasible or nongeneralizable. However, traditional approaches do not always deliver unconfounded causal conclusions in practice. The rise of "doubly robust" nonparametric tools coupled with the growth of deep learning for capturing rich representations of multimodal data offers a unique opportunity to develop and test such models for causal inference on comprehensive electronic health records (EHRs). In this article, we investigate causal modeling of an RCT-established causal association: the effect of classes of antihypertensive on incident cancer risk. We develop a transformer-based model, targeted bidirectional EHR transformer (T-BEHRT) coupled with doubly robust estimation to estimate average risk ratio (RR). We compare our model to benchmark statistical and deep learning models for causal inference in multiple experiments on semi-synthetic derivations of our dataset with various types and intensities of confounding. In order to further test the reliability of our approach, we test our model on situations of limited data. We find that our model provides more accurate estimates of relative risk [least sum absolute error (SAE) from ground truth] compared with benchmark estimations. Finally, our model provides an estimate of class-wise antihypertensive effect on cancer risk that is consistent with results derived from RCTs.

Association of Lung Cancer Risk With the Presence of Both Lung Nodules and Emphysema in a Lung Cancer Screening Trial.

The coexistence of emphysema and lung nodules could interact with each other and then lead to potential higher lung cancer risk. The study aimed to explore the association between emphysema combined with lung nodules and lung cancer risk. A total of 21,949 participants from the National Lung Screening Trial (NLST) who underwent low-dose computed tomography (LDCT) examination were included. Participants were categorized into four groups (NENN group (non-emphysema and non-nodules), E group (emphysema without nodules), N group (nodules without emphysema), and E + N group (nodules with emphysema)) according to whether there were lung nodules and emphysema. Multivariable Cox regression and stratified analyses were performed to estimate the association between the four groups and lung cancer risk. Among the 21,949 participants, there were 9,040 (41.2%), 5,819 (26.5%), 4,737 (21.6%), and 2,353 (10.7%) participants in the NENN group, E group, N group, and E + N group. The risk of lung cancer incidence increased in turn in NENN group, E group, N group and E + N group. Compared with NENN group, the age-adjusted hazard ratios (HRs) (95% confidence intervals (CIs)) of lung cancer incidence were 2.07 (1.69 - 2.54) for E group, 4.13 (3.47 - 5.05) for N group, and 6.26 (5.14 - 7.62) for E + N group. The association was robust to adjustment for potential confounders (1.83 (1.47 - 2.27) for E group, 3.97 (3.24 - 4.86) for N group, and 5.23 (4.28 - 6.48) for E + N group). Comparable results as the lung cancer incidence were observed for lung cancer mortality, whether in age-adjusted model (E group: 1.85 (1.39 - 2.46), N group: 2.49 (1.89 - 3.29), E + N group: 4.27 (3.21 - 5.68)) or fully adjusted model (E group: 1.56 (1.15 - 2.11), N group: 2.43 (1.81 - 3.26), E + N group: 3.39 (2.50 - 4.61)). However, the trend of all-cause mortality risk among the four groups was somewhat different from that of lung cancer risk, whether in age-adjusted model (1.37 (1.21 - 1.54) for E group, 1.06 (0.92 - 1.21) for N group, and 1.75 (1.51 - 2.02) for E + N group) or fully adjusted model (1.26 (1.10 - 1.44) for E group, 1.09 (0.94 - 1.27) for N group, and 1.52 (1.30 - 1.79) for E + N group). Based on a large-scale lung cancer screening trial in the United States, this study demonstrated that either emphysema or lung nodules can increase lung cancer risk, and lung nodules combined with emphysema can further increase the lung cancer risk and all-cause mortality. The significance of these findings for lung cancer screening should be evaluated.

Association between prolactin increasing antipsychotic use and the risk of breast cancer: a retrospective observational cohort study in a United States Medicaid population.

Results of retrospective studies examining the relationship between prolactin increasing antipsychotics and incident breast cancer have been inconsistent. This study assessed the association between use of high prolactin increasing antipsychotics (HPD) and the incidence of breast cancer using best practices in pharmacoepidemiology. Using administrative claims data from the MarketScan Medicaid database, schizophrenia patients initiating antipsychotics were identified. Those initiating HPD were compared with new users of non/low prolactin increasing drugs (NPD). Two definitions of breast cancer, two at-risk periods, and two large-scale propensity score (PS) adjustment methods were used in separate analyses. PS models included all previously diagnosed conditions, medication use, demographics, and other available medical history. Negative control outcomes were used for empirical calibration. Five analysis variants passed all diagnostics for sufficient statistical power and balance across all covariates. Four of the five variants used an intent-to-treat (ITT) approach. Between 4,256 and 6,341 patients were included in each group for the ITT analyses, and patients contributed approximately four years of follow-up time on average. There was no statistically significant association between exposure to HPD and risk of incident breast cancer in any analysis, and hazard ratios remained close to 1.0, ranging from 0.96 (95% confidence interval 0.62 - 1.48) to 1.28 (0.40 - 4.07). Using multiple PS methods, outcome definitions and at-risk periods provided robust and consistent results which found no evidence of an association between use of HPD and risk of breast cancer.

Abstract 828: Associations of perfluoroalkyl substances with breast cancer incidence risk and mediation role of mitochondrial DNA copy number: A prospective case-cohort study

Abstract Background: Perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs), notable representatives of perfluoroalkyl substances (PFASs), are synthetic persistent chemicals widely accumulated and detected in humans. Short-chain PFASs [PFCAs with carbon number &amp;lt;8 and PFSAs &amp;lt;6, e.g. perfluoroheptanoic acid (PFHpA)] are considered less bioaccumulative and increasingly used in commercial products, yet their health impacts are rarely investigated. Perfluorooctanoic acid (PFOA) has been categorized as a possible human carcinogen (group 2B) and a potential mammary toxicant. However, few population studies explored the prospective associations of PFOA and other common PFASs with breast cancer risk nor the underlying mechanisms. Methods: Hence, we conducted a case-cohort study within the DongFeng-Tongji Cohort, compromising 226 incident breast cancer cases and a random sub-cohort of 990 individuals. Plasma concentrations of four PFCAs [PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and PFHpA] and two PFSAs [perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS)], as well as peripheral blood mitochondrial DNA copy number (mtDNAcn) levels, were measured at baseline. Results: Using Barlow-weighted Cox regression, we found 35% and 20% increased incident risk of breast cancer for each 1-unit ln-transformed increase in PFOA and PFHpA, respectively [HR (95% CI) = 1.35 (1.03, 1.78) and 1.20 (1.02, 1.40)]. Quantile g-computation analysis revealed a 19% increased incident risk of breast cancer along with each simultaneous quartile increase in all ln-transformed PFCA concentrations [HR (95% CI) = 1.19 (1.01, 1.41)], driven mainly by contributions from PFOA (56%), PFNA (24%), and PFHpA (20%). Besides, mtDNAcn was positively associated with PFHpA levels [β (95% CI) =0.027 (0.005, 0.048)], but not with PFOA or PFNA (P&amp;gt;0.05). We also found significantly higher breast cancer risk in participants with the highest mtDNAcn (Q4, ≥1.52) than those with the lowest (Q1, &amp;lt;0.87) [HR (95% CI) =2.92 (1.69, 5.04)], and that mtDNAcn mediated 12.77% of PFHpA-breast cancer association [Indirect effect, HR (95% CI) =1.02 (1.00, 1.04)]. No significant mediation effect of mtDNAcn was observed in associations of PFOA and PFNA with breast cancer (P&amp;gt;0.05). Conclusions: Our work unveiled the relationship of short-chain PFHpA with increased incident risk of breast cancer for the first time and highlighted the intermediate role of mtDNAcn in this association, providing a research clue for exploring the potential mechanisms of PFAS-induced breast cancer. Moreover, co-exposure to PFASs was observed as a risk factor for breast cancer, shedding light on breast cancer prevention by regulating PFASs as a chemical class. Citation Format: Yue Feng, Huan Guo. Associations of perfluoroalkyl substances with breast cancer incidence risk and mediation role of mitochondrial DNA copy number: A prospective case-cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 828.

Abstract 2179: Microbiome-derived metabolites mediate carcinogenic alterations of breast tissue in the context of obesity

Abstract Obesity increases the relative risk for breast cancer incidence. Multiple molecular mechanisms linked to obesity drive breast cancer progression. Obesity shifts the gut microbiome in ways that may increase breast cancer risk. Microbial-associated molecular pattern (MAMP)-proteins and metabolites could directly affect breast epithelial cell signaling. In this study, we focused on lipopolysaccharide (LPS), a structural component of the outer membranes of gram-negative bacteria and a toll-like receptor 4 (TLR4)-agonist. Systemic LPS levels are known to increase in obesity. We hypothesize that chronic low-grade inflammation caused by LPS contributes to breast cancer initiation. To test this hypothesis, we first quantified levels of LPS, along with a panel of adipokines/cytokines, in serum samples from women (n= 33; BMI range= 18.3-45.3 Kg/m2; Age range= 18-51 years). Women with elevated serum LPS had significantly higher BMI, leptin, and leptin/adiponectin ratio, confirming a link between systemic LPS and metabolic markers of obesity. Other biomarkers of breast cancer risk include DNA damage. Analyses of non-cancerous breast tissue sections from matched donors revealed higher densities of DNA double-strand breaks (estimated based on 53BP1 foci counts) in women with high serum LPS. Experiments with HMT-3522 S1 breast acini showed that LPS increases DNA break frequencies and oxidative stress levels in 3D structures of mammary epithelium. Moreover, LPS increases oxidative lesions in the DNA (estimated based on 8-oxoguanine fluorescence in MCF-10A cells) that may lead to increased LPS-mediated DNA damage. Patient obesity status was associated with alterations in oxidative modifications in the breast proteome. We also found that LPS disrupts epithelial polarity, a hallmark of breast tissue homeostasis. In mammary epithelium, LPS activates the nuclear factor-kappa B (NFκB) pathway by binding to the TLR4 receptor, leading to an increased expression of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α). Interestingly, TLR4 blockade prevented the loss of apical polarity and DNA damage induced by LPS. Last, but not least, we show an association between LPS immunogenicity (anti-LPS IgA concentrations) and participant BMI in non-cancerous breast tissue samples. These novel findings show that LPS is a key systemic and local mediator of the obesity-modulated microbiome that increases breast cancer risk. The outcomes of our study underscore the importance of considering the microbiome in the prevention of breast cancer. Citation Format: Mohamed Gaber, Kayla Neary, Julia Holmes, Adam S. Wilson, Adam J. Katz, Pierre-Alexandre Vidi, Katherine L. Cook. Microbiome-derived metabolites mediate carcinogenic alterations of breast tissue in the context of obesity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2179.

Abstract 3436: Circadian rhythm dysregulation with risk of gastrointestinal cancers: A large-scale prospective analysis

Abstract Introduction: The incidence of multiple gastrointestinal (GI) cancers has been rising among younger adults with unknown etiology. Circadian rhythm dysregulation due to increasing exposures to artificial lighting, irregular work hours, and frequent travel, has been recently linked with multiple diseases. Disruption of the circadian clock drives Apc LOH to hyperactivate Wnt signaling and enhances MYC-dependent glycolytic metabolism to accelerate colorectal cancer progression. However, the association between circadian rhythm dysregulation, quantified by relative amplitude (RA)–a parameter derived from rest-activity patterns, and risk of colorectal and other GI cancers has not been evaluated in epidemiologic studies. Methods: We prospectively examined the associations between RA and risk of incident GI cancers among 87,653 UK Biobank participants who wore an Axivity AX3 triaxial accelerometer over 7 days (2013-15) with follow-up to 2021. RA was derived and averaged across all valid days, using the difference between the mean activity levels during the most active 10-hour period and the least active 5-hour period. Cox models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs). Results: During 512,074 person-years, 1,079 incident GI cancer cases occurred. After multivariable adjustment, lower RA was associated with an increased risk of overall GI cancer (RR per SD [standard deviation] = 1.12, 95% CI 1.04-1.21, P for trend = 0.01). Compared to individuals in the highest tertile (T1), those with RA in the lowest tertile (T3) had a 25% increased risk of overall GI cancer (RR = 1.25, 95% CI 1.05-1.50). The positive associations with GI cancers were mainly driven by gastric cancer (RR per SD = 1.33, 95% CI 1.02-1.74, P for trend= 0.04) and colon cancer (RR per SD = 1.13, 95% CI 1.00-1.28, P for trend = 0.03). Conclusion: In this large-scale, prospective analysis of accelerometer data, circadian rhythm dysregulation was associated with subsequent risk of GI cancers, primarily gastric and colon cancer. To our knowledge, this is among the first population-based studies reporting the positive link between circadian rhythm dysregulation with cancer risk. Citation Format: Yi Kang, Shinghei Mok, Xiaoyu Zong, Yin Cao. Circadian rhythm dysregulation with risk of gastrointestinal cancers: A large-scale prospective analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3436.