Journal of the National Cancer Institute最新文献

{"title":"A prediction model for metachronous colorectal cancer: development and validation","authors":"Ye Zhang, Amalia Karahalios, Aung Ko Win, Enes Makalic, Alex Boussioutas, Daniel D Buchanan, Stephanie L Schmit, N Jewel Samadder, Finlay A Macrae, Mark A Jenkins","doi":"10.1093/jnci/djaf191","DOIUrl":"https://doi.org/10.1093/jnci/djaf191","url":null,"abstract":"Background Being able to estimate a colorectal cancer case’s risk of metachronous colorectal cancer could enable risk-appropriate surveillance. The aim was to develop a risk prediction model to estimate individual 10-year risk of metachronous colorectal cancer following a colorectal cancer diagnosis. Methods A cohort of population-based colorectal cancer cases were recruited soon after their diagnosis between 1997 and 2012 from America, Canada, and Australia. Cox regression with the least absolute shrinkage and selection operator penalization was used to identify factors that predicted the risk of a new primary colorectal cancer diagnosed at least one year after the initial colorectal cancer. Potential predictors included demography, anthropometry, lifestyle factors, comorbidities, personal and family cancer history, medication use, and diagnosis age and pathological features of the first colorectal cancer. Internal validation through bootstrapping was used to evaluate the discrimination and calibration. Results 6,085 colorectal cancer cases were included. 138 (2.3%) were diagnosed with metachronous colorectal cancer over a median of 12 years (interquartile range 5 − 17 years). Metachronous colorectal cancer risk was predicted by body mass index, smoking, physical activity, family history of cancer and synchronous colorectal cancer, stage, grade, histological type and DNA mismatch repair status and diagnosis age of the first colorectal cancer. The model was valid with a c-statistic of 0.65 (95% CI: 0.63 − 0.68) and a calibration slope of 0.873 (standard deviation: 0.087). Conclusions Metachronous colorectal cancer can be predicted with reasonable accuracy by this prediction model that consists of clinical variables collected as part of routine practice.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144645389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"U.S. cancer deaths prevented due to survival improvements stratified by extent of disease, 2010-2019","authors":"Meredith S Shiels, Neal D Freedman, Anika T Haque, Amy Berrington de González, Stanley Lipkowitz, Douglas R Lowy, Ruth M Pfeiffer","doi":"10.1093/jnci/djaf192","DOIUrl":"https://doi.org/10.1093/jnci/djaf192","url":null,"abstract":"Background Progress against cancer mortality has been driven by primary prevention, early detection, and cancer treatment. We estimated the number of cancer deaths that were avoided due to stage-specific improvements in cancer survival among patients diagnosed in 2010-2019 followed through 2020. Methods We utilized cancer incidence data from 17 Surveillance, Epidemiology and End Results (SEER) cancer registries during 2004-2019. We estimated the number of cancer deaths prevented due to cancer- and stage-specific survival improvements (based on SEER summary stage) as the observed minus expected number of cancer deaths through 2020. We calculated the expected number of cancer deaths from estimated cumulative incidence models setting the calendar year effect to 2009. Results During 2010-2019, there were 3,310,270 incident cancers and 966,733 cancer deaths through 2020 in SEER-17. Improvements in stage-specific cancer survival resulted in a 4.7% (95%CI -5.3%, -4.2%) decline in cancer deaths in females (22,874 fewer deaths) and a 4.4% (95%CI -4.9%, -3.9%) decline in males (23,198 fewer deaths) in SEER-17 regions, corresponding to approximately 173,900 fewer cancer deaths in the full U.S. population. The largest absolute declines were for lung and liver cancers, while the largest relative declines were observed for melanoma and leukemia. Cancer deaths prevented were not statistically significant for colorectal or prostate cancers. All statistical tests were two-sided. Conclusions Stage-specific survival gains, reflecting treatment advances and improved access to cancer treatment from 2010-2019, resulted in an estimated 173,900 fewer cancer deaths among US cancer patients diagnosed during this time period.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144645465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polygenic risk of coronary artery disease for long-term survivors of breast cancer","authors":"Gordon P Watt, Anne S Reiner, Xiang Shu, Kathleen E Malone, Julia A Knight, Esther M John, Eric J Chow, Charles F Lynch, Lene Mellemkjær, Meghan Woods, Xiaolin Liang, Anh Phong Tran, Jung Hun Oh, Andriy Derkach, Jonine L Bernstein","doi":"10.1093/jnci/djaf189","DOIUrl":"https://doi.org/10.1093/jnci/djaf189","url":null,"abstract":"Aim Cardiovascular disease is a leading cause of death for long-term breast cancer survivors. We evaluated whether a polygenic risk score for coronary artery disease (CAD-PRS) was associated with the risk of incident CAD for survivors of unilateral or contralateral breast cancer. Methods The study included 1,307 women with breast cancer first diagnosed at age <55 years who participated in the WECARE Follow-up Study. The CAD-PRS was based on a PRS developed and validated in a separate population. We modelled the association between incident CAD and the CAD-PRS, adjusting for age, CAD risk factors, first (and second) breast cancer treatment, study recruitment phase, and genetic population stratification. We also explored whether the risk of CAD depended on interactions between the CAD-PRS and cardiotoxic cancer treatment. Results There were 65 incident CAD diagnoses reported at a median of 16 years after breast cancer diagnosis. Participants with CAD-PRS≥median had a 2.48-times increased risk of CAD (95%CI = 1.44-4.29) relative to participants with CAD-PRS<median. Anthracycline-based chemotherapy was associated with increased CAD risk (HR = 2.04, 95%CI = 1.04-3.98), and the association was not modified by the CAD-PRS. The association between incident CAD and left-sided RT was increased for those with CAD-PRS≥median (HR = 2.90, 95% CI = 1.26-6.68), but not for those with CAD-PRS<median (HR = 0.96, 95% CI 0.32-2.88). There was evidence of super-additive interaction between the CAD-PRS and left-sided RT (relative excess risk due to interaction = 2.06, 95% CI 0.05-4.06). Conclusions A genome-wide CAD-PRS was associated with non-fatal CAD risk for long-term breast cancer survivors, providing potential utility for personalized cardiovascular care, particularly after RT.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"679 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144639767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clonal hematopoiesis and risk of non-myeloid subsequent malignant neoplasms after autologous hematopoietic cell transplantation","authors":"June-Wha Rhee, Sitong Chen, Raju Pillai, Alysia Bosworth, Artem Oganesyan, Emma Grigorian, Liezl Atencio, Caitlyn Estrada, Mareen Kassabian, Lanie Lindenfeld, Rusha Bhandari, Scott Goldsmith, Michael Rosenzweig, Alex F Herrera, Matthew G Mei, Ryotaro Nakamura, F Lennie Wong, Stephen J Forman, Saro H Armenian","doi":"10.1093/jnci/djaf181","DOIUrl":"https://doi.org/10.1093/jnci/djaf181","url":null,"abstract":"Purpose Examine the association between clonal hematopoiesis (CH) and non-myeloid subsequent malignant neoplasms (SMNs) after autologous hematopoietic cell transplantation (HCT). Methods This was a retrospective cohort study of 1,931 consecutive patients who underwent HCT between 2010 and 2016 at a single center. DNA from pre-HCT mobilized blood products was sequenced to identify CH variants (variant allele frequency [VAF] ≥2%). The primary outcome was 8-year(y) cumulative incidence (CI) of non-myeloid SMNs. Multivariable regression analysis was used to evaluate the association between CH and non-myeloid SMNs, as well as cause-specific mortality. Results Median age at HCT was 58.8 y (range 18.4-78.1y); 389 patients (20.1% of the cohort) had at least one CH variant and 94 (4.9%) had ≥2 variants. The 8 y CI of non-myeloid SMNs was significantly higher in patients with CH compared to those without (15.1% vs 7.2%, p < .001), and increased by VAF: 7.2% (VAF <2%), 14.0% (VAF 2– <10%), 19.4% (VAF ≥10%); p = .001. Patients with CH had a two-fold increased risk of non-myeloid SMNs (standardized incidence ratio = 1.9), compared with the general population. In multivariable analysis, CH was an independent and significant risk factor for non-myeloid SMNs (hazard ratio [HR]=1.72, 95%CI 1.15–2.59). Finally, patients with CH had significantly worse survival, primarily due to the higher risk of non-relapse mortality (HR: 2.97, 95%CI: 1.90-4.64). Conclusions CH was significantly associated with risk of non-myeloid SMNs after HCT, and the magnitude of association increased by VAF. CH may serve as a biomarker for identifying HCT survivors at higher risk for developing non-myeloid SMNs.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144594153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incidence of rare cancers during the COVID-19 pandemic: a US population-based study","authors":"Cameron B Haas, Jeremy Miller, Meredith S Shiels, Ruth M Pfeiffer, Eric A Engels","doi":"10.1093/jnci/djaf175","DOIUrl":"https://doi.org/10.1093/jnci/djaf175","url":null,"abstract":"Background Recent media reporting has suggested an increase in the incidence of rare cancers in 2021 as a result of the COVID-19 pandemic, raising concern for possible carcinogenic effects of severe acute respiratory syndrome coronavirus 2 infection. We aimed to identify cancers that increased in incidence in the United States during 2021 compared with 2018-2019. Methods We analyzed data from Surveillance, Epidemiology, and End Results (SEER-22) using a systematic classification schema including rare cancers. We estimated age-standardized incidence rate ratios (aIRRs) comparing the year 2021 to 2018-2019 for 693 individual cancer types and highlight those with an aIRR>1 based on a Bonferroni-corrected p-value threshold. Cancer types of particular interest included cholangiocarcinoma, diffuse large B-cell lymphoma, Kaposi sarcoma and lung cancer. Results Among 693 unique cancer types evaluated, nine showed a significant increase in incidence in 2021 compared to 2018-2019 and did not also increase in prior years, including four subtypes of thymoma (type-A aIRR=2.50; type-AB aIRR=2.78; type-B aIRR=1.90; type not otherwise specified aIRR=1.60), granulosa cell tumor of the ovary (aIRR=2.72), peripheral neuroectodermal tumors of the bone (aIRR=10.6) and soft tissue (aIRR=3.20), pheochromocytoma (aIRR=4.59), and paraganglioma (aIRR=3.30). Increases for all nine cancer types could be attributed to changes in cancer registry reporting practice. Cancer types of particular interest did not increase in incidence during 2021. Conclusions Our study does not support an increase in cancer incidence in the United States in 2021 due to the COVID-19 pandemic. It is important to monitor future trends, which may reveal longer-term effects of COVID-19.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144594160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Meeting trial eligibility in follicular lymphoma patients is associated with overall survival but not progression-free survival","authors":"Kimberly S Q Wong, Arina Martynchyk, Zoe Krisnadi, Fiona Swain, Ahmad Zargari, Luke Cassidy, Georgia Mills, Kenneth Lim, Jeremy Gervasi, Portia Smallbone, Jenny Wang, Olivia Slifirski, Zoe Loh, Chan Cheah, Colm Keane, Gareth Gregory, Masa Lasica, Geoffrey Chong, Allison Barraclough, Tara Cochrane, Denise Lee, Eliza Hawkes","doi":"10.1093/jnci/djaf174","DOIUrl":"https://doi.org/10.1093/jnci/djaf174","url":null,"abstract":"Background Clinical trial eligibility criteria are necessary for safety and target population homogeneity; however, increasingly restrictive organ function eligibility rarely preclude standard therapies and impede clinical application of trial results. Methods This multicentre, retrospective study applied safety-related eligibility criteria from four landmark phase III trials (GALLIUM, RELEVANCE, StiL NHL1, BRIGHT) to 528 treatment-naïve follicular lymphoma (FL) patients receiving standard immunochemotherapy. Results 55% were ineligible for at least one study and 12% were ineligible for all four studies. Ineligible patients were more likely aged over 60 years with poorer performance status compared to eligible patients (p < .05 respectively). There was no difference between response rate or progression-free survival (PFS) of eligible vs ineligible patients. Patients ineligible for all trials had inferior 5-year overall survival (OS) compared to patients eligible for at least one study (69% vs 92%, p < .001). More than half of deaths were due to causes other than lymphoma. Conclusion In summary, current trials select populations with favourable OS despite similar disease-based outcomes. Patients suitable for standard chemoimmunotherapy should not be routinely excluded based on age, performance status and organ function from frontline randomised trials with PFS primary endpoints. There is a significant need to broaden trial eligibility to include all patients fit for standard treatment to correctly benchmark new therapies.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144594152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling non-small cell lung cancer treatment effect heterogeneity: a comparative analysis of statistical methods.","authors":"Jessica A Lavery,Yuan Chen,Katherine S Panageas,Yuanjia Wang","doi":"10.1093/jnci/djaf176","DOIUrl":"https://doi.org/10.1093/jnci/djaf176","url":null,"abstract":"For patients with advanced non-small cell lung cancer lacking targetable genomic alterations, the impact of clinico-genomic characteristics on the effectiveness of combining chemotherapy with immunotherapy is unclear. We evaluated four statistical methods for detecting heterogeneous treatment effects (HTE) related to clinical factors, including programmed death-ligand 1 (PD-L1) expression, tumor mutation burden (TMB), and stage at diagnosis, using the American Association for Cancer Research Project GENIE BPC dataset supplemented with institutional data collected under the same data curation model. A two-sided p-value ≤0.05 was used to denote statistical significance for all analyses. The mixture model revealed two latent subgroups: in one subgroup, there was no meaningful treatment effect, with average PFS only 5% longer with immunotherapy alone (95% confidence interval [CI] -19%, 35%); in the second subgroup, immunotherapy alone was associated with a 35% decrease in average PFS (95% CI -59%, 2%), corresponding to a ratio in treatment effects of 1.62 (95% CI 1.02, 2.57). There was a marginal association between lower TMB levels and membership in the subgroup with improved PFS following receipt of chemoimmunotherapy. The causal survival forest highlighted the importance of TMB (variable importance ranking: 1) and PD-L1 (variable importance ranking: 3) when assessing heterogeneity. In contrast, the accelerated failure time and Cox proportional hazards models did not detect any statistically significant HTE. In simulations, the mixture model identified HTE more frequently than other methods, especially with weak covariate relationships, demonstrating its utility for informing personalized treatment approaches.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"690 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144593977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between glucagon-like peptidase 1 receptor agonist and obesity-related cancer in overweight or obese patients with type 2 diabetes: a nationwide cohort study","authors":"Xianhua Mao, Xinrong Zhang, Linda Henry, Ka Shing Cheung, Man-Fung Yuen, Ramsey Cheung, Wai-Kay Seto, Mindie H Nguyen","doi":"10.1093/jnci/djaf163","DOIUrl":"https://doi.org/10.1093/jnci/djaf163","url":null,"abstract":"Background Evidence regarding the effect of glucagon-like peptidase 1 receptor agonist (GLP-1a), when compared with other glucose-lowering drugs (oGLD), on obesity-related cancer (ORC) in overweight or obese patients with type 2 diabetes (T2D) is limited. Methods Using Merative™ Marketscan® Research Databases, we identified all overweight or obese patients with T2D aged 20-79 years who received GLP-1a or oGLD in the U.S. between January 2016 and June 2021. The primary outcome was ORC, defined as a component of 13 cancer types. Results Among 919,609 overweight or obese individuals with T2D (mean [SD] age, 52.3 [10.9] years; female, 53.5%), 16,653 newly diagnosed ORC were recorded during the 2,086,526 person-years of follow-up. GLP-1a users (vs oGLD users) were associated with lower incidence (7.5 vs 8.1 per 1000 person-years) and risk of ORC (adjusted hazard ratio [aHR] 0.87, 95%CI 0.83-0.91). This significant association was consistent when comparing GLP-1a with metformin (aHR 0.90, 95%CI 0.86-0.95), dipeptidyl peptidase-4 inhibitor (aHR 0.88, 95%CI 0.84-0.93), thiazolidinediones (aHR 0.84, 95%CI 0.71-0.99), sulfonylureas (aHR 0.81, 95%CI 0.74-0.88), sodium-glucose transport protein 2 inhibitor (aHR 0.73, 95%CI 0.66-0.80), insulin (aHR 0.70, 95%CI 0.65-0.76), all P <.05, and was strengthened with increasing weight (overweight, mild-to-moderate, and severe obesity HR 0.95, 95%CI 0.81-1.10 vs 0.90, 95%CI 0.84-0.97 vs 0.82, 95%CI 0.77-0.88; Pinteraction = .032). Conclusions In a nationwide U.S. cohort of overweight or obese patients with T2D, GLP-1a, when compared with oGLD, was associated with a lower risk of ORC, with more pronounced risk reduction with increasing body weight.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144594158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-invasive colorectal cancer screening: simple may be optimal.","authors":"David Lieberman,Uri Ladabaum","doi":"10.1093/jnci/djaf171","DOIUrl":"https://doi.org/10.1093/jnci/djaf171","url":null,"abstract":"","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144578617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breastfeeding after breast cancer in young BRCA carriers","authors":"Eva Blondeaux, Virginia Delucchi, Elene Mariamidze, Rinat Bernstein-Molho, Sophie Frank, Alberta Ferrari, Sabine Linn, Hee Jeong Kim, Elisa Agostinetto, Shani Paluch-Shimon, Laura Cortesi, Antonio Di Meglio, Judith Balmana, Rinat Yerushalmi, Kenny A Rodriguez-Wallberg, Tiphaine Renaud, Wanda Cui, Halle C F Moore, Stephanie M Wong, Katarzyna Pogoda, Maryam Lustberg, Kelly-Anne Phillips, Sileny Han, Fabio Puglisi, Claudio Vernieri, Jyoti Bajpai, Amir Sonnenblick, Christine Rousset-Jablonski, Laura De Marchis, Ugo De Giorgi, Giampaolo Bianchini, Luis Texeira, Francois P Duhoux, Cynthia Villarreal-Garza, Valentina Sini, Robert Fruscio, Lucia Del Mastro, Isabelle Demeestere, Hatem A Azim, Fedro A Peccatori, Ann H Partridge, Matteo Lambertini","doi":"10.1093/jnci/djaf177","DOIUrl":"https://doi.org/10.1093/jnci/djaf177","url":null,"abstract":"Background We investigated safety of breastfeeding after breast cancer in patients carrying germline BRCA pathogenic or likely pathogenic variants. Methods This was an international, multicentre, hospital-based, retrospective cohort study including BRCA carriers diagnosed with stage I-III invasive breast cancer at age 40 years or younger between January 2000 and December 2020 (NCT03673306). Locoregional recurrences and/or contralateral breast cancers, disease-free survival (DFS) and overall survival (OS) were compared between patients who breastfed after delivery and those who did not. Results Among 4732 patients included from 78 centres worldwide, 659 had a pregnancy after breast cancer diagnosis, of whom 474 delivered a child. After excluding patients with uptake of bilateral risk-reducing mastectomy prior to delivery (n = 225) or unknown breastfeeding status (n = 71), 110 (61.8%) breastfed (median duration 5 months) and 68 (38.2%) did not breastfeed. Compared to patients in the no breastfeeding group, those who breastfed were more frequently nulliparous at breast cancer diagnosis (61.8% vs 45.6%) and did not report prior smoking habit (71.8% vs 57.4%). After a median follow up of 7.0 years following delivery, 7-year cumulative incidence of locoregional recurrences and/or contralateral breast cancers was 29% in the breastfeeding group and 37% in the no breastfeeding group (adjusted subdistribution hazard ratio[HR]=1.08, 95%CI 0.57-2.06). No difference in DFS (aHR = 0.83, 95%CI 0.49-1.41) nor in OS (aHR = 1.32, 95%CI 0.31-5.66) was observed. Conclusions Breastfeeding did not appear to be associated with a higher risk of developing locoregional recurrences or contralateral breast cancers, emphasizing the possibility of achieving a balance between maternal and infant needs without compromising oncological safety.","PeriodicalId":501635,"journal":{"name":"Journal of the National Cancer Institute","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144577994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}