A model for individualized risk prediction of contralateral breast cancer.
Patients diagnosed with invasive breast cancer (BC) or ductal carcinoma in situ are increasingly choosing to undergo contralateral prophylactic mastectomy (CPM) to reduce their risk of contralateral BC (CBC). This is a particularly disturbing trend as a large proportion of these CPMs are believed to be medically unnecessary. Many BC patients tend to substantially overestimate their CBC risk. Thus, there is a pressing need to educate patients effectively on their CBC risk. We develop a CBC risk prediction model to aid physicians in this task.



We used data from two sources: Breast Cancer Surveillance Consortium and Surveillance, Epidemiology, and End Results to build the model. The model building steps are similar to those used in developing the BC risk assessment tool (popularly known as Gail model) for counseling women on their BC risk. Our model, named CBCRisk, is exclusively designed for counseling women diagnosed with unilateral BC on the risk of developing CBC.



We identified eight factors to be significantly associated with CBC-age at first BC diagnosis, anti-estrogen therapy, family history of BC, high-risk pre-neoplasia status, estrogen receptor status, breast density, type of first BC, and age at first birth. Combining the relative risk estimates with the relevant hazard rates, CBCRisk projects absolute risk of developing CBC over a given period.



By providing individualized CBC risk estimates, CBCRisk may help in counseling of BC patients. In turn, this may potentially help alleviate the rate of medically unnecessary CPMs.
Department of Mathematical Sciences, University of Texas at Dallas, 800 W Campbell Rd, FO 35, Richardson, TX, 75080, USA.
Marzana
M
Chowdhury
Division of Surgical Oncology, Johns Hopkins University, Baltimore, USA.
David
D
Euhus
Department of Community and Family Medicine, Geisel School of Medicine at Dartmouth, Hanover, USA.
Tracy
T
Onega
Department of Mathematical Sciences, University of Texas at Dallas, 800 W Campbell Rd, FO 35, Richardson, TX, 75080, USA. swati.biswas@utdallas.edu.
Swati
S
Biswas
Department of Mathematical Sciences, University of Texas at Dallas, 800 W Campbell Rd, FO 35, Richardson, TX, 75080, USA. pankaj@utdallas.edu.
Pankaj K
PK
Choudhary
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D018426:SEER Program; D055815:Young Adult
Absolute risk; Breast Cancer Surveillance Consortium; Breast density; CBCRisk; Contralateral breast cancer; SEER