Surgical Management of Breast Cancer in 2010-2011 SEER Registries by Hormone and HER2 Receptor Status

Time interval between breast cancer diagnosis and surgery is associated with disease outcome

Time interval between breast cancer (BC) diagnosis and surgery is of concern to patients and clinicians, but its impact on survival remains unclear. We identified 5130 BC patients receiving surgery between 2009 and 2017 from the Shanghai Jiaotong University Breast Cancer Database (SJTU-BCDB), and divided as Ruijin cohort and SJTU cohort. All participants were divided into three groups according to the interval between diagnosis and surgery: ≤ 1 week, 1-2 weeks, and > 2 weeks. Among 3144 patients of Ruijin cohort, the estimated 5-year breast cancer-free interval (BCFI) rates for the ≤ 1 week, 1-2 weeks and > 2 weeks groups were 91.8%, 87.5%, and 84.0% (P = 0.088), and the estimated 5-year overall survival (OS) rates were 95.6%, 89.6%, and 91.5% (P = 0.002). Multivariate analysis showed that patients with a TTS > 2 weeks had significantly lower BCFI (HR = 1.80, 95%CI 1.05-3.11, P = 0.034) and OS (HR = 2.07, 95% CI 1.04-4.13, P = 0.038) rates than patients with a TTS ≤ 1 week. Among 5130 patients when combining Ruijin cohort with SJTU cohort, the estimated 5-year BCFI rates for the ≤ 1 week, 1-2 weeks, and > 2 weeks groups were 91.0%, 87.9%, and 78.9%, and the estimated 5-year OS rates for the ≤ 1 week, 1-2 weeks, and > 2 weeks groups were 95.8%, 90.6%, and 91.5%, both with a significantly p value < 0.001. Our findings demonstrated the prolonged time to surgery (more than 2 weeks) after BC diagnosis was associated with poor disease outcomes, suggesting that efforts to early initiate treatment after diagnosis need to be pursued where possible to improve survival.

The role of tumor phenotype in the surgical treatment of early-stage breast cancer

BACKGROUND

We investigated whether tumor phenotype influences surgical decision-making, and how that may impact overall survival (OS) for early-stage breast cancer.

METHODS

Women aged 18-69 with cT0-2/cN0/cM0 breast cancer in the National Cancer Database (2010-2017) were included. A generalized logistic model was used to identify factors associated with surgery type. A Kaplan-Meier curve was used to visualize unadjusted OS, and the log-rank test was used to test for differences in OS between surgery types.

RESULTS

Of 597,149 patients, 58% underwent lumpectomy with radiation (BCT), 25% unilateral mastectomy (UM), and 17% bilateral mastectomy (BM). After adjustment, HER2+ and triple-negative (TN) tumors were less likely to undergo UM than BCT, versus hormone receptor-positive tumors (OR = 0.881, 95% CI = 0.860-0.903; OR = 0.485, 95% CI = 0.470-0.501). UM and BM had worse 5-year OS versus BCT (UM: 0.926, vs BM: 0.952, vs BCT: 0.960).

CONCLUSIONS

BCT is increasingly used to treat HER2+ and TN tumors. More extensive surgery is not associated with better survival outcomes, regardless of tumor phenotype.

Perioperative magnetic resonance imaging in breast cancer care: Distinct adoption trajectories among physician patient-sharing networks

BACKGROUND

Despite no proven benefit in clinical outcomes, perioperative magnetic resonance imaging (MRI) was rapidly adopted into breast cancer care in the 2000's, offering a prime opportunity for assessing factors influencing overutilization of unproven technology.

OBJECTIVES

To examine variation among physician patient-sharing networks in their trajectory of adopting perioperative MRI for breast cancer surgery and compare the characteristics of patients, providers, and mastectomy use in physician networks that had different adoption trajectories.

METHODS AND FINDINGS

Using the Surveillance, Epidemiology, and End Results-Medicare database in 2004-2009, we identified 147 physician patient-sharing networks (caring for 26,886 patients with stage I-III breast cancer). After adjusting for patient clinical risk factors, we calculated risk-adjusted rate of perioperative MRI use for each physician network in 2004-2005, 2006-2007, and 2008-2009, respectively. Based on the risk-adjusted rate, we identified three distinct trajectories of adopting perioperative MRI among physician networks: 1) low adoption (risk-adjusted rate of perioperative MRI increased from 2.8% in 2004-2005 to 14.8% in 2008-2009), 2) medium adoption (8.8% to 45.1%), and 3) high adoption (33.0% to 71.7%). Physician networks in the higher adoption trajectory tended to have a larger proportion of cancer specialists, more patients with high income, and fewer patients who were Black. After adjusting for patients' clinical risk factors, the proportion of patients undergoing mastectomy decreased from 41.1% in 2004-2005 to 38.5% in 2008-2009 among those in physician networks with low MRI adoption, but increased from 27.0% to 31.4% among those in physician networks with high MRI adoption (p = 0.03 for the interaction term between trajectory group and time).

CONCLUSIONS

Physician patient-sharing networks varied in their trajectory of adopting perioperative MRI. These distinct trajectories were associated with the composition of patients and providers in the networks, and had important implications for patterns of mastectomy use.

Impact of surgical management of primary tumors in stage IV breast cancer patients: a retrospective observational study based on SEER database

OBJECTIVES

Although primary tumour surgery could prolong survival for patients with stage IV breast cancer, how to select candidates for primary tumour surgery is still a challenging problem for medical oncologists.

DESIGN

This study is a retrospective database study.

SETTING AND PARTICIPANTS

In this study, we aimed at evaluating the primary site surgery effect and select the beneficial subgroups. 13 618 patients with stage IV breast cancer, diagnosed between 2010 and 2015, were collected from SEER*Stat database.

INTERVENTIONS

Based on the local surgery at primary tumour site, patients were categorised into three groups: primary tumour surgery performed group, recommended for primary tumour surgery but refused (RBR) group and surgery not recommended (NR) group.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause survival and breast cancer-specific survival (BCSS).

RESULTS

Univariate Cox regression analyses showed that, compared with surgery group, patients in non-surgery (RBR and NR) groups tend to be older, T4, N0/NX, triple-negative and visceral metastatic. For both all-cause survival and BCSS, non-surgery, advanced T stage, triple-negative BC (TNBC) and visceral metastases were significant risk factors. Primary tumour surgery showed benefits for both all-cause survival (HR=0.44, 95% CI=0.39-0.49, p<0.0001) and BCSS (HR=0.43, 95% CI=0.38-0.49, p<0.0001). However, after propensity score matching, primary tumour surgery failed to demonstrate significant benefits for TNBC (HR=0.96, 95% CI=0.60-1.53, p=0.851) and patients with visceral metastases (HR=0.90, 95% CI=0.60-1.36, p=0.62).

CONCLUSION

Surgery was associated with prolonged survival in stage IV breast cancers, but not in patients with TNBC and visceral metastases.

Triple-negative breast cancer: current treatment strategies and factors of negative prognosis

Breast cancer is the most common cancer in women and the most common cause of death in working-age women. According to the results of immunohistochemical studies, 10-20% of cases revealed a triple-negative type of breast cancer. This subtype is characterized by significant proliferative activity and growth rate, aggressive clinical course, and early metastasis. This leads to a suspicious prognosis and, accordingly, encourages an increase of surgical treatment radicalism and aggressive systemic treatment. This review briefly analyzes existing treatment strategies for triple-negative breast cancer with a focus on surgical treatment. Surgical treatment is an integral part of complex therapy. Currently, the attention of researchers is focused not only on the radicalism of the operation, ensuring long-term survival, but also on achieving a good cosmetic result that determines the quality of life of patients. In this aspect, organ-preserving and prosthetic methods of operations are promising, the feasibility and effectiveness of which are being discussed. The relevance of choosing the optimal method of operation is evidenced by the lack of generally accepted approaches based on informative markers for the prognosis of the course of the disease. Therefore, the choice of the optimal method of surgical treatment taking into account the individual characteristics of the patient and the tumor, indications for chemotherapy, and radiation therapy remains an unresolved issue and requires further research.

A population-based comparison of treatment, resource utilization, and costs by cancer stage for Ontario patients with HER2-positive breast cancer

PURPOSE

We sought to expand the currently limited, Canadian, population-based data on the characteristics, treatment pathways, and health care costs according to stage in patients with human epidermal growth factor receptor-2 positive (HER2+) breast cancer (BC).

METHODS

We extracted data from the publicly funded health care system in Ontario. Baseline characteristics, treatment patterns, and health care costs were descriptively compared by cancer stage (I-III vs. IV) for adult women diagnosed with invasive HER2+ BC between 2012 and 2016. Resource use was multiplied by unit costs for publicly funded health care services to calculate costs.

RESULTS

Overall, 4535 patients with stage I-III and 354 with stage IV HER2+ BC were identified. Most patients with stage I-III disease were treated with surgery (4372, 96.4%), with the majority having a lumpectomy, and 3521 (77.6%) received radiation. Neoadjuvant (NAT) and adjuvant (AT) systemic treatment rates were 20.1% (n = 920) and 88.8% (n = 3065), respectively. Systemic treatment was received by 311 patients (87.9%) with metastatic HER2+ BC, 264 of whom (84.9%) received trastuzumab. Annual health care costs per patient were nearly 3 times higher for stage IV vs. stage I-III HER2+ BC.

CONCLUSION

Per-patient annual costs were substantially higher for women with metastatic HER2+ BC, despite less frequent exposure to surgery and radiation compared to those with early stage disease. Increasing NAT rates in early stage disease represent a critical opportunity to prevent recurrence and reduce the costs associated with treating metastatic HER2+ BC.

A population-based comparison of treatment patterns, resource utilization, and costs by cancer stage for Ontario patients with hormone receptor-positive/HER2-negative breast cancer

PURPOSE

To update and expand on data related to treatment, resource utilization, and costs by cancer stage in Canadian patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC).

METHODS

We analyzed data for adult women diagnosed with invasive HR+/HER2- BC between 2012 and 2016 utilizing the publicly funded health care system in Ontario. Baseline characteristics, treatment received, and health care use were descriptively compared by cancer stage (I-III vs. IV). Resource use was multiplied by unit costs for publicly funded health care services to calculate costs.

RESULTS

Our study included 21,360 patients with stage I-III plus 813 with stage IV HR+/HER2- BC. Surgery was performed on 20,510 patients with stage I-III disease (96.0%), with the majority having a lumpectomy, and radiation was received by 15,934 (74.6%). Few (n = 1601, 7.8%) received neoadjuvant and most (n = 15,655, 76.3%) received adjuvant systemic treatment. Seven hundred and fifty eight patients with metastatic disease (93.2%) received systemic therapy; 542 (66.7%) received endocrine therapy. Annual per patient health care costs were three times higher in the stage IV vs. stage I-III cohort with inpatient hospital services representing nearly 40% of total costs.

CONCLUSION

The costs associated with metastatic HR+/HER2- BC reflect a significant disease burden. Low endocrine treatment rates captured by the publicly funded system suggest guideline non-adherence or that a fair portion of Ontarian patients may be incurring out-of-pocket drug costs.

Factors related to re-excision procedures following primary breast-conserving surgery for women with breast cancer in the U.S. Military Health System

BACKGROUND AND OBJECTIVES

Re-excision surgery is undertaken to obtain clear margins after breast-conserving surgery (BCS) for localized breast cancer. This study examines patient and tumor characteristics related to re-excision surgery in the universal-access Military Health System (MHS).

METHODS

Retrospective analysis of patients with pathologically confirmed stage I-III breast cancer between 1998 and 2014 in the Department of Defense Central Cancer Registry and MHS Data Repository-linked databases who received primary BCS. Multivariable stepwise logistic regression methods identified characteristics associated with re-excision surgery (lumpectomy and mastectomy) and conversion to mastectomy, given as adjusted odds ratios (AOR) and 95% confidence intervals (CIs).

RESULTS

Of 7637 women receiving BCS, 26.3% had a re-excision and 9.9% converted to mastectomy. Tumor location, larger tumor size (≥4 cm), and regional lymph node involvement were associated with a greater likelihood of re-excision and mastectomy conversion. Pathology before BCS (AOR, 0.39; 95% CI, 0.35, 0.44 for re-excision) and neoadjuvant treatment (AOR, 0.50; 95% CI, 0.36, 0.69 for re-excision) were associated with a decreased likelihood of these outcomes. Additionally, age, tumor histology, and military-specific variables were associated with mastectomy conversion.

CONCLUSION

Comprehensive preoperative workup, including tumor pathology, may better inform surgical decision-making and reduce re-excision rates.

Breast cancer in young black women

BACKGROUND

Young age at breast cancer diagnosis is associated with negative prognostic outcomes, and breast cancer in black women often manifests at a young age. This study evaluated the effect of age on breast cancer management and outcomes in black women.

METHODS

This was a retrospective cohort study of all black women treated for invasive breast cancer between 2005 and 2010 at a specialized tertiary-care cancer centre. Clinical and treatment characteristics were compared by age. Kaplan-Meier methodology was used to estimate overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 666 black women were identified. Median BMI was 30 (range 17-56) kg/m² and median tumour size was 16 (1-155) mm. Most tumours were oestrogen receptor-positive (66·4 per cent). Women were stratified by age: less than 40 years (74, 11·1 per cent) versus 40 years or more (592, 88·9 per cent). Younger women were significantly more likely to have a mastectomy, axillary lymph node dissection and to receive chemotherapy, and were more likely to have lymphovascular invasion and positive lymph nodes, than older women. The 5-year OS rate was 88·0 (95 per cent c.i. 86·0 to 91·0) per cent and the 5-year DFS rate was 82·0 (79·0 to 85·0) per cent. There was no statistically significant difference in OS by age (P = 0·236). Although DFS was inferior in younger women on univariable analysis (71 versus 88 per cent; P < 0·001), no association was found with age on multivariable analysis.

CONCLUSION

Young black women with breast cancer had more adverse pathological factors, received more aggressive treatment, and had worse DFS on univariable analysis. Young age at diagnosis was, however, not an independent predictor of outcome.

Assessing the Impact of CALGB 9343 on Surgical Trends in Elderly-Women With Stage I ER+ Breast Cancer: A SEER-Based Analysis

Purpose: Lumpectomy (L) and breast radiotherapy (RT) results in equivalent outcomes in comparison to mastectomy (M) for early-stage breast cancer (BC) based on randomized controlled trials (RCT). Since 2004, RCT support that L without RT yields equivalent survival and acceptable local-regional outcomes in women ≥70-years old with T1N0 hormone-sensitive (ER+) BC on endocrine therapy. Based on this, we hypothesized that M rates should decrease substantially after 2004 in this low-risk elderly population.

Methods: We used the Surveillance Epidemiology and End Results registry data to conduct this study. We included women with T1N0 ER+ BC from 2000 to 2014. We compared M rates in women diagnosed from 2000 to 2004 vs. 2005–2012 using the Chi-Square test. Logistic regression analyses was performed to examine demographic/clinical factors associated with mastectomy.

Results: 67,506 women met the study criteria. In elderly Stage I ER+ BC, the M rate decreased by 6.3%: 29.0% before 2004 to 22.7% after 2004 (p < 0.0001). M rates remained higher in elderly non-Hispanic black (NHB, 27.1%, p < 0.0001), non-Hispanic Asian-Pacific-Islander (NHAPI, 30.1%, p < 0.0001), and Hispanics (24.4%, p = 0.0004) vs. non-Hispanic White (NHW, 21.5%). Treatment in the modern cohort was associated with decreased odds of mastectomy (OR = 0.71, 95% CI 0.68-0.74, p < 0.0001) while NH-API race was associated with the highest increased odds of mastectomy (OR = 1.65, 95% 1.53-1.78, p < 0.0001). In the modern cohort specifically (2005–2014), Hispanic women (OR = 1.12, p = 0.014), NHB women (OR = 1.21, p < 0.0001), and NHAPI women (OR = 1.73, p < 0.0001) all had higher odds of undergoing mastectomy relative to NHW women after adjusting for all other patient and tumor related factors.

Conclusions: In elderly patients with stage I, ER+ BC, M rates have decreased modestly since 2004. These trends are driven mostly be decreases in the M rate in NHW women, but M rates remain ~25% in Hispanic, NHB, and NHAPI women. Further research is needed to identify why M, which is associated with higher cost and morbidity than L alone, has not changed substantially in elderly, low-risk BC.

Where youth matters-clinicopathologic characteristics and emerging trends in treatment and outcomes in young Irish women with breast cancer

BACKGROUND

Young women with breast cancer (YWBC) represent 7-12% of breast cancer diagnoses and ostensibly have more biologically aggressive subtypes with higher relapse and mortality rates. We studied the clinical and pathological characteristics in YWBC and examined how outcomes and treatment have evolved.

METHODS

YWBC were identified from pathology databases at two tertiary centers. Patients were divided into two cohorts: those diagnosed from 2000 to 2005 (C1) and from 2006 to 2015 (C2). Data were retrieved from clinical, radiology, and histology databases. Statistical analysis was performed using R® (V3.2.0).

RESULTS

We identified 345 patients. Median age was 36 years (23-39 years). Mastectomy was performed in 232 patients (67.2%) and axillary lymph node clearance (ALNC) in 207 patients (60% [C1 82.7 vs. C2: 49.4%, p < 0.001]). One hundred-seventy patients (49%) were ER + HER2-, 88 (25.5%) were HER2+, and 58 (16.8%) were triple negative. Eighty patients (23.2%) received neoadjuvant therapy. Pathological complete response rates were statistically similar between C1 and C2 [C1 1 (0.9%) vs C2 16 (6.8%) p = 0.1]. Distant relapse occurred in 59 (19%) patients. There was a higher relapse rate (RR) in C1 [27 (32.1%) vs. 32 (15.7%), p < 0.002). HER2+ and ER+ HER2- patients in C1 had higher RRs than C2. Median overall survival in patients with metastatic disease was 29 months (range 2-119 months).

CONCLUSION

Locally advanced disease was more prevalent in YWBC. Mastectomy and ALNC rates were high and most received multimodal treatment. The extent of axillary surgery declined over time. Outcomes were unchanged in triple negative patients. These remain a priority for research.

The Effect of Receptor Status on Mastectomy and Contralateral Prophylactic Mastectomy Rates in Early Stage Invasive Breast Carcinoma

BACKGROUND

There is an established relationship between hormone receptor (HR; estrogen and/or progesterone receptors) status, HER2 status, and locoregional recurrence. The purpose of this study was to analyze how HR and HER2 receptor status have influenced the surgical management trends among patients with early stage breast cancer.

PATIENTS AND METHODS

The National Cancer Database was queried for patients with cT1 to cT3, cN0, and cM0 breast carcinoma from 2004 to 2012. Patients were grouped on the basis of receptor status and surgical management (mastectomy or breast-conserving surgery [BCS]). Multivariable analyses were performed to investigate factors associated with increased odds of receiving mastectomy over BCS. Among a subgroup of patients who underwent ipsilateral mastectomy, analyses were performed to determine any association between contralateral prophylactic mastectomy (CPM) and receptor status.

RESULTS

We found 280,241 patients who met inclusion criteria for analyzing mastectomy or BCS surgical decision. Patients with HER2-positive (HER2⁺) tumors (HR⁺/HER⁺ and HR^-/HER2⁺) were the most likely to undergo mastectomy (odds ratio [OR], 1.212 and 1.499 respectively, compared with HR⁺/HER2^- patients, each P < .001). HR status alone did not affect ipsilateral surgical management as patients with HR⁺/HER2^- and HR^-/HER2^- tumors demonstrated similar mastectomy rates (P = .391). Among the 108,018 who underwent mastectomy, 20% underwent CPM. After adjustment, patients with HR⁺/HER2⁺, HR^-/HER2⁺, and HR^-/HER2^- were all more likely to undergo CPM (OR 1.356, 1.608, and 1.358, respectively compared with HR⁺/HER2^- patients, each P < .001).

CONCLUSION

This analysis indicates that patients with early stage breast cancer are more likely to undergo a mastectomy and CPM if they have HER2⁺ tumors.

Routine Pre-Treatment MRI for Breast Cancer in a Single-Payer Medical Center: Effects on Surgical Choices, Timing and Outcomes

Introduction: Pre-operative MRI is being used with increasing frequency to evaluate breast cancer patients, but the debate surrounding risks and benefits of this use continues. At our institution, we instituted a standardized protocol for pre-operative MRI. Here, we compare patients seen prior to routine use of MRI to those seen after and examine effects on surgical choices, timing and outcomes.

Methods: This is a retrospective review of a prospectively collected database of all new invasive breast cancers seen from January 2007 to December 2012. The control group (CG) did not receive MRI, while the MRI group (MRG) underwent MRI according to our pretreatment protocol. Groups were compared with regards to basic demographics, initial surgical choices, need for re-excision, and surgical timing. The electronic medical records of patients in the MRG who underwent mastectomy as their initial surgery were examined closely to determine the main factors leading to their choice of surgery. Finally, correlation between findings on MRI and final surgical pathology was analyzed.

Results: Of 282 patients included, 38 were in the CG and 244 in the MRG; the groups were well matched. The MRG had a significantly higher percentage of patients choosing initial mastectomy (MRG: 47.1% vs CG 21.1%, p=0.003). Patients seen in the first 2 years of the study were less likely to choose mastectomy than those enrolled in the latter years (29.2%vs 48.6%, p=0.004). The MRG had a lower chance of return to the operating room for re-excision (15.2% vs 28.9%, p=0.035). The average time from initial imaging to initial surgery was approximately the same between groups (MRG: 39.7 days vs CG 42.1 days, p=0.45) and the MRG actually had shorter time to definitive (margin-negative) surgical management (MRG: 43.5 days vs CG: 50.3 days, p=0.079). One hundred-fifteen patients in the MRG underwent mastectomy as initial surgery. Of these, 64 (55.7%) had no additional findings on MRI and chose mastectomy based on patient preference; 30 patients (26.1%) (29 unilateral, 1 bilateral) had mastectomy because of MRI findings. Of the 31 breasts removed (29 unilateral and 1 bilateral mastectomies) because of MRI findings, 26 (83.9%) had histologic findings that correlated with the MRI findings, while 5 (16.1%) did not.

Conclusion: Patients receiving routine pre-treatment MRI had an increased mastectomy rate, but had a lower re-excision rate. We found no delay to initial surgical therapy and, perhaps more importantly, a slight decrease in time to margin-negative surgical therapy in the MRI group. Women choosing mastectomy after MRI did so because of personal preference over half of the time, while MRI findings influenced this choice in 26% of these women. When MRI findings did lead to mastectomy, these findings were confirmed by pathology results in the vast majority of cases.

Trends in the use of mastectomy in women with small node-negative breast cancer treated at US academic centers

Breast-conserving surgery (BCS) provides equivalent survival outcomes to unilateral mastectomy. There is no survival advantage to bilateral mastectomy in average risk breast cancer. Among a cohort of breast cancer patients expected to be candidates for BCS, we examined choice of surgery and factors associated with it. A prospective cohort study of unilateral clinical Stage I breast cancer patients treated at National Comprehensive Cancer Network centers from 2000 to 2009 was performed. The proportion of patients who initially underwent mastectomy versus BCS and time to definitive surgery and chemotherapy were examined. Of 10,249 patients, 23 % underwent mastectomy as an initial surgery. No decline in the use of mastectomy as initial surgery was found. There was significant institutional variation, with rates of initial mastectomy ranging from 14 to 30 % (adjusted odds ratio: 0.42-1.38). Tumor characteristics were associated with surgical option, but with small absolute differences. Of those who received initial mastectomy, 22 % had bilateral mastectomy, with an increase over time (2000:13 % vs. 2009:30 %) and substantial institutional variation (11-34 %). Women treated with initial mastectomy had longer median times from diagnosis to complete definitive surgery (6 vs. 4 weeks) and to start of adjuvant chemotherapy (12 vs. 11 weeks). Among Stage I breast cancer, the overall use of mastectomy did not change significantly over 10 years; however, an increasing proportion of women with unilateral cancer had bilateral mastectomy, and there was wide variation in type of surgery by institution. Further studies to assess reasons for the observed wide variation are warranted.

Her2 positivity and race predict higher mastectomy rates: a SEER database analysis

Given the difference in incidence of biologic subtype of breast cancer between black and white women, and the potential disparity in type of surgery in black and white women presenting with early stage breast cancer, this study aimed to examine the odds of mastectomy compared to lumpectomy by molecular subtype in black and white women with size T1 and T2 invasive breast cancer. Using the SEER database, breast operation choice for women over the age of 15 with T1 or T2 tumors between 2010 and 2012 were examined. Tumors were categorized according to the Breast Subtype variable in the SEER database and data were stratified by tumor size and race. Bivariate comparisons and logistic regression models adjusted for age were used. In women with T1 or T2 tumors, mastectomy rates were higher in women with Her2 positive tumors than in those with Her2 negative tumors. When Her2 results are the same among comparison groups, those women with HR positive tumors were less likely to undergo a mastectomy than those with HR negative tumors. In T1 tumors, the magnitude of the association was larger for white women than women of other races. Results suggest there are differences in surgical decision making based on breast cancer subtype in women with T1 or T2 tumors and that race may play a role for size T1 tumors. The strong association between Her2 positive tumors and higher mastectomy rates warrants further investigation.