癌症治疗延迟是公认的更糟糕结果的标志。及时治疗可能与医生患者共享网络特征相关，但这仍然没有得到充分研究。旨在检查外科医生和护理团队患者共享网络措施与乳腺癌治疗延迟之间的关联。这项针对美国人群医疗保险索赔的横断面研究基于 2017 年至 2020 年进行的设置。合格的参与者包括接受手术的乳腺癌患者和继续接受辅助治疗的子集。患者共享网络是为治疗医生而构建的。对 2023 年 9 月至 2024 年 2 月的数据进行了分析。评估了外科医生关键评分（衡量当地独特性或稀缺性的指标）和护理密度（衡量医生团队熟悉程度的指标）。如果外科医生的关键得分位于前 15%，则他们被视为关键。患者医生团队的护理密度是根据接受手术治疗的患者的术前团队和接受辅助治疗的患者的术后团队计算的。主要结局是手术和辅助延迟，定义为活检和手术之间的时间超过 60 天，手术和辅助治疗之间的间隔分别超过60天。研究队列包括56433名患者（18004名70-74岁[31.9%]），其中大部分来自城市地区（44931名患者[79.6%]）。在这些患者中，8009 例（14.2%）经历了手术延误。关键外科医生身份（当地独特的外科医生）与手术延迟没有统计学相关性；然而，与术前护理密度低的患者相比，术前护理密度高（即团队熟悉度高）的患者手术延迟的几率较低（比值比 [OR]，0.58；95% CI，0.53-0.63）。在术后接受辅助治疗的 29458 名患者中，有 5700 名（19.3%）经历了辅助延迟。与非关键外科医生相比，关键外科医生的患者辅助延迟的几率更大（OR，1.30；95% CI，1.13-1.49）。与术后护理密度低的患者相比，术后护理密度高（OR，0.77；95% CI，0.69-0.87）和术后护理密度中等（OR，0.85；95% CI， 0.77-0.94）。在这项医疗保险索赔横断面研究中，捕捉医生稀缺性和团队熟悉程度的网络测量与及时治疗相关。这些结果可能有助于指导系统级干预措施，以减少癌症治疗的延误。

Cancer treatment delay is a recognized marker of worse outcomes. Timely treatment may be associated with physician patient-sharing network characteristics, yet this remains understudied.To examine the associations of surgeon and care team patient-sharing network measures with breast cancer treatment delay.This cross-sectional study of Medicare claims in a US population-based setting was conducted from 2017 to 2020. Eligible participants included patients with breast cancer who received surgery and the subset who went on to receive adjuvant therapy. Patient-sharing networks were constructed for treating physicians. Data were analyzed from September 2023 to February 2024.Surgeon linchpin score (a measure of local uniqueness or scarcity) and care density (a measure of physician team familiarity) were assessed. Surgeons were considered linchpins if their linchpin score was in the top 15%. The care density of a patient's physician team was calculated on preoperative teams for surgically-treated patients and postoperative teams for adjuvant therapy-receiving patients.The primary outcomes were surgical and adjuvant delay, which were defined as greater than 60 days between biopsy and surgery and greater than 60 days between surgery and adjuvant therapy, respectively.The study cohort included 56 433 patients (18 004 aged 70-74 years [31.9%]) who were mostly from urban areas (44 931 patients [79.6%]). Among these patients, 8009 (14.2%) experienced surgical delay. Linchpin surgeon status (locally unique surgeon) was not statistically associated with surgical delay; however, patients with high preoperative care density (ie, high team familiarity) had lower odds of surgical delay compared with those with low preoperative care density (odds ratio [OR], 0.58; 95% CI, 0.53-0.63). Of the 29 458 patients who received adjuvant therapy after surgery, 5700 (19.3%) experienced adjuvant delay. Patients with a linchpin surgeon had greater odds of adjuvant delay compared with those with a nonlinchpin surgeon (OR, 1.30; 95% CI, 1.13-1.49). Compared with those with low postoperative care density, there were lower odds of adjuvant delay for patients with high postoperative care density (OR, 0.77; 95% CI, 0.69-0.87) and medium postoperative care density (OR, 0.85; 95% CI, 0.77-0.94).In this cross-sectional study of Medicare claims, network measures capturing physician scarcity and team familiarity were associated with timely treatment. These results may help guide system-level interventions to reduce cancer treatment delays.