Abstract P5-02-01: Characteristics of physician detected breast cancer
Authors: Malmgren JA , Atwood MK , Kaplan HG 
Published: March 2017

Background: Clinical breast examination (CBE) conducted as a part of a routine or annual physical exam is no longer recommended by the American Cancer Society. The U.S. Preventive Services Task Force has not issued any guideline on use of CBE stating there is not enough evidence to recommend for or against the practice.

Methods: A retrospective cohort study was conducted of all physician detected breast cancers (BC) stage 0-IV (N=641) in a dedicated institutional breast cancer registry research database from 1990-2014 (n=12081). Method of detection was chart abstracted at time of diagnosis. Categories are 1) physician or health care professional detection (PhysD) of a palpable lump or abnormality at routine examination prompting a BC work up and diagnosis; 2) patient detection (PtD) of breast symptoms such as a palpable lump, pain, swelling or bleeding which prompted a doctor visit and subsequent BC diagnosis; and 3) mammography detected (MamD) disease discovered by routine mammogram in the absence of complaints or known physical findings. Patients with 'other' or 'missing' diagnosis method were excluded (n=214). Bivariate, multivariate and survival analysis were used to compare characteristics and disease specific survival (DSS).

Results: Over the 25 year time period 5% of breast cancers were PhysD (n=641), 38% PtD (n=4556) and 60% MamD (n=6852). Percentage of PhysD BC decreased from 9% to 3% over time as relative incidence of MamD BC increased with the number per year remaining constant (20-40 cases/year). On average PhysD BC cases were older than PtD BC and younger than MamD BC cases [mean age PtD = 53 years, PhysD = 58 years, MamD = 60 years, p&lt;.001] with significantly more PhysD cases age 75 and older [PtD = 8%, PhysD = 15%, MamD = 12%, p&lt;.001]. PhysD BC was 56% stage II-IV vs. 23% MamD BC but less than PtD BC (69%) (p&lt;.001). PhysD BC was more likely to be hormone receptor negative (15%) and more likely to be triple negative (ER-/PR-/Her2neu-) (11%) than MamD BC (6% for each) (p&lt;.001). Mean tumor size of PhysD BC was significantly larger than MamD BC and significantly smaller than PtD BC [MamD BC = 1.69 cm (95% CI = 1.62, 1.76), PhysD BC = 2.55 cm (95% CI = 2.39, 2.70), PtD BC = 3.23 (95% CI = 3.16, 3.31) p&lt;.001). Histology for PhysD BC cases was 7% less ductal and 3% more lobular than either PtD or MamD BC. PhysD BC was less likely to be seen on subsequent mammography (21%) than PtD BC (17%) (p&lt;.001). In a multinomial regression model, PhysD BC differed significantly by age, stage and HR status when compared to PtD and MamD BC (p&lt;.001). In disease specific survival analysis of the invasive BC cases, the PhysD cases had significantly better DSS than the PtD BC cases but worse DSS than the MamD BC cases [5 year DSS: PtD = 92%, PhysD = 95%, MamD = 98%; 10 year DSS: PtD = 85%, PhysD = 92%, MamD = 95% (p=.004 PhysD vs. PtD, p&lt;.001 PhysD vs. MamD).

Conclusions: Clinically detected breast cancer consistently presents as a small but significant portion of the breast cancer population. Physician detected breast cancer is less often seen on subsequent mammogram even after presentation of a palpable mass. While the percentage is modest the cost is minimal. CBE should continue to be taught and practiced by primary care physicians.

Citation Format: Malmgren JA, Atwood MK, Kaplan HG. Characteristics of physician detected breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-02-01.