1. Increase in the Use of Double Mastectomies for the Treatment of Early-Stage Breast Cancer in California Cyllene R. Morris, DVM, PhD California Cancer Registry

2. isk of contralateral breast cancer (BC) Risk of contralateral breast cancer (BC) Estimated risk: 0.5% - 1% per year risk in BRCA1-BRAC2 carriers, family history risk if lobular carcinoma in situ (LCIS) (risk for invasive lobular carcinomas?) risk in HR negative than HR+ breast cancers

3. Prophylactic Contralateral Mastectomy (PCM) After BC, limited options available: Tamoxifen (ER+), screening, and PCM Radical procedure: for most women, no effect on survival ◦Exception: small benefit in young women with ER (-), higher risk of second primary? 1 1 Bedrosian I, Hu CY, Chang GJ. J Natl Cancer Inst 2010;102:401-9

4. Recent Increase in PCM PCM rates from 1.8% in 1998 to 4.5% in 2003 (SEER): young age, white race, lobular tumors associated with PCM 2 PCM doubled in NY between 1995-2005, similar predictors 3 2 Tuttle TM, Habermann EB, Grund EH, Morris TJ, Virnig BA. J Clin Oncol 2007;25:5203-9 3 McLaughlin CC, Lillquist PP, Edge SB. Cancer 2009; 115:5404-12

5. Recent increase in Use of MRI LCIS detected by MRI (but not by mammogram) MRI use: incidence of LCIS PCM rates

6. Objectives Use data in the California Cancer Registry (CCR) database to: Describe trends in PCM in California Evaluate predictors of PCM

7. Study Population BC diagnosed 2000-2009 AJCC Stages 0-II Surgically treated Microscopically confirmed Only tumor ever diagnosed 156,106 cases

8. Data Analysis Proportions and trends tested by Chi- Square Logistic Regression: Odds of receiving PCM as opposed to mastectomy or breast-conserving surgery

9. Study Population PCMBCS/Mastectomy N%N% Race/Ethnicity NH White5,6735.2102,84394.8 NH Black2302.68,66297.4 Hispanic7923.323,54496.7 Asian/ PI5382.918,02197.1 Age at DX < 401,14911.48,97088.6 40-543,3826.548,26493.5 55-641,6854.139,02595.9 65-747402.330,98897.7 75+2771.125,85698.9 Marital Status Married4,8815.190,16694.9 Not Married2,2793.760,09796.3 Unknown732.52,84097.5

10. PCMBCS/Mastectomy N%N% AJCC Stage In Situ1,7025.131,41694.9 (LCIS)1915.43,22594.6 I2,6033.767,61096.3 II2,9285.154,07794.9 ER Positive/Unk5,9484.4129,17395.6 Negative/Bord1,2855.123,93094.9 Grade Low (I/II)3,8874.191,85995.9 High (III/IV)3,3465.261,24494.8 Histology Lobular15646.422,87993.6 Other5,6694.2130,22495.8 Insurance Private/Other6,0555.6101,64494.4 Medicare7072.231,48697.8 Medicaid3382.314,33397.7 Not/Unknown1352.35,64897.7

16. FACTOROR95% CI HistologyDuctal /Other1- Lobular1.711.61 – 1.81 AJCC StageStage I1- In Situ1.281.21 – 1.36 Stage II1.211.14 – 1.30 Tumor GradeLow (I/II)1 High (III/IV)1.171.11 – 1.24 ER StatusPositive/Unk1 Negative1.081.01 – 1.16 Multivariate Odds Ratios (OR) for PCM

17. FACTOROR95% CI InsuranceNo/Unknown1- Medicaid1.000.82 – 1.23 Medicare*1.651.36 – 2.00 Private/Other2.131.79 – 2.53 Race/EthnicityWhite1- Black0.430.38 – 0.49 Hispanic0.500.46 – 0.54 Asian/PI0.420.39 – 0.46 Multivariate Odds Ratios (OR) for PCM * PCM not covered by Medicare

18. FACTOROR95% CI Age at DX≥ 751- 65 – 741.121.01 – 1.24 55 – 641.821.66 – 2.00 40 – 542.852.62 – 3.10 < 404.764.37 – 5.18 Marital StatusNot Married1- Married1.171.11 – 1.23 Multivariate Odds Ratios (OR) for PCM All models adjusted to year of diagnosis

19. Conclusions Use of PCM in California increased 2 – 4 fold in all groups (except 75 and older) Women more likely to opt for PCM if:  Young (< 40)  White  Privately insured  Married  Diagnosed with stage II or in situ  Lobular carcinoma  High grade, ER negative

20. Possible Reasons (1): Increased use of MRI  Incidence of LCIS in California: stable since 2000 BUT  If enhancement foci found, women may elect PCM and forgo further tests!

21. Incidence of Lobular Carcinoma In Situ: California, 1988-2007

22. Possible Reasons (2): High risk of second tumor?  Women at high risk: BRAC1/BRAC2 carriers, family history  Genetic testing becoming mainstream (but no information available in CCR)

23. Possible Reasons (3): Fear  Risk usually overestimated: lack of information?  However, because of scrutiny, second cancers more likely to be detected early

24. Possible Reasons (4): Peace of mind (avoid stress of repeated screenings) Cosmetic symmetry, if mastectomy recommended (None better than only one – but loss of sensation across the chest…) Plastic surgeon preference (easier reconstruction)

25. Comments in a newspaper article NYT: After Cancer, Removing a Healthy Breast March 8, 2010 Get done with it Fear of losing insurance Society too obsessed with breasts Chemo and radiation side effects Lack of trust in medical professionals (specially when felt mishandled)

26. Another option: waiting Study of 27 patients (UK)* requesting PCM, not recommended by surgeon: After 12 months “cooling” period:  All patients less anxious about risk  23 (85.2%) glad after waiting  4 (14.8%) still requested PCM * Chaundhry & Sahu, European BC Conference, March 2010

27. Conclusion Use of PCM increasing dramatically in California Are patients getting all the facts? Waiting may benefit low/moderate risk patients Patients have the final decision and choose what feels right to them