Abstract P1-08-28: Impact of surgery and time to surgery on breast cancer survival in the United States, 2004–2014 (N=2,211,245)

Abstract

Background: Surgery is very common for patients diagnosed with breast cancer. Its impact on survival depends on diagnostic, patient, tumor-related, and other-treatment factors. Moreover, time to surgery from the date of diagnosis is also a critical factor affecting outcome. Objective: In this study we investigated the impact of surgery on survival in breast cancer patients using two methods: (1) multivariate regression; and (2) propensity score matching. For the patients undergoing surgical intervention, we aimed to identify the optimum time from diagnosis to surgery. Methods: The study population was taken from the National Cancer Database over the years 2004 through 2014. Of 2,211,245 patients, 99.1% were female, 0.9% male, 85% non-Hispanic white, 10.5% black, 0.7% Hispanic, and 14.5% other races. Mean age of the patient population was 60.0 ± 13.4 years (range: 18–90). The majority of the patients (92.9%) underwent a surgical procedure. Results: Overall, the patients who did not undergo surgery were 6.7 times more likely to die within the study time period (95% confidence interval [CI]: 6.7–6.8, p<0.001) than those who did. However, after adjusting for patients' demographics, tumor-related factors, cancer stages, and combination of other treatments, the risk for dying of patients without surgery was 2.3 times higher (hazard ratio [HR]: 2.3, 95% CI: 2.3–2.4, p<0.001). In the propensity-matched cohort of 51,630 patients that was divided equally into two groups — those who underwent surgery and those who did not — the risk of mortality remained 2.4 times higher for patients without surgery (HR: 2.4, 95% CI: 2.3–2.4, p<0.001). Regarding time to surgery from the date of diagnosis, patient survival was best for the patients whose time to surgery ranged from 31 to 60 days. The next best timeframe was 61 to 90 days, followed by 30 days or fewer, then 91 to 120 days, and finally 120 and more days (p<0.001). Conclusion: Using two different statistical methods, surgery is clearly an independent predictor of survival for patients with breast cancer. After matching for other factors, patients not having surgery were more than twice as likely to die as their surgical counterparts. Time to surgery from the date of diagonosis confirmed ealier findings that surgery is most benificial within 2–3 months from the date of diangosis. These findings can provide clinical guidance to clinicians and patients for planning treatment. Citation Format: Singh M, Konduri SD, Bobustuc GC, Rovin RA, Kassam AB. Impact of surgery and time to surgery on breast cancer survival in the United States, 2004–2014 (N=2,211,245) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-08-28.