Session 1: Mortality Rates in Women Ages 40 and Older Diagnosed with Breast Cancer according to Method of Detection

Purpose: To determine the impact of following CTFPHC guidelines on method of detection of breast cancer on tumor stage, treatment, and mortality in women ≥40y.

Materials and Methods: This retrospective study assessed all consecutive women age ≥40y diagnosed with breast cancer at a tertiary referral center in 2016. All patient information was reviewed. Odds ratios(OR) and 95% confidence intervals(CI) were computed using univariate, multivariable, and proportional odds models to determine the impact of age, method of detection(screen-detected(SD), symptomatic or incidental), breast tissue density(BI-RADS 5thed.), AJCC 8thed. pathologic stage, tumor histology, hormone receptor (estrogen, progesterone, and HER2neu) status, treatment (type of surgery, chemotherapy and radiation therapy), and mortality at 4.3 years of follow-up. Chi-squared tests were performed to evaluate the association between method of detection and mortality and treatment among four age cohorts: 40-49, 50-59, 60-74 and ≥75y.

Results: 823 patients (mean age+/-standard deviation 62.5 +/-12.2y) were evaluated, 698/823(84.8%) invasive cancers and 125/823(15.2%) ductal carcinoma in situ. More symptomatic cancers were found in 40-49y (92/133(69.2%)) and ≥75y (77/135(57%)) than 50-59y (89/214(41.6%) or 60-74y (87/341(25.5%) cohorts. There were 52/823(6.3%) deaths overall with higher proportions of deaths in the lower screened cohorts 40-49y(9/133 (6.8%)) and ≥75y(11/135(8.2%)), than 50-59y(12/214(5.6%)) and 60-74y(20/341(5.9%)). Symptomatic cancers had 2.23 (95% CI: 1.23-4.03; p=0.0082) higher odds of death compared with SD when adjusted for age. There were 367/823(44.6%) advanced breast cancers (≥Stage IIA) in total, 234/367(63.8%) symptomatically detected. More advanced cancers were found symptomatically in 40-49y(64/68(94.1%)) and ≥75y(57/77(74%)), than 50-59y(59/97(60.8%)) or 60-74y(54/114(47.4%)). Symptomatic cancers had 5.88 (95% CI: 4.3-8.07; p<0.0001) higher odds of having advanced cancer compared to a lower stage.
Multivariable analysis found that HER2neu receptor status (OR=1.72(1.16-2.54), chemotherapy (OR=1.90(1.35-2.66), death (OR=3.82(2.21-6.58) and age at diagnosis (OR=1.02(1.00-1.03) were associated with higher tumor stage(all p< 0.01). Univariate analysis found higher odds of mastectomy (OR=1.704(1.27-2.29) p=0.0004) in symptomatic as compared to SD women.

Conclusion: SD as compared to symptomatic detection in women ≥40 y had 5.88 times lower odds of advanced breast cancer and 2.23 times lower odds of death at 4.3 years follow-up.

Clinical Relevance Statement: Following CTFPHC breast cancer guidelines of only screening women 50-74y led to more advanced cancers with higher odds of death and more extensive treatment.