Private insurance is associated with better outcomes in multiple common cancers. We hypothesized that insurance status would significantly impact outcomes in primary breast sarcoma (PBS) due to the additional challenges of diagnosing and coordinating specialized care for a rare cancer. Using the National Cancer Database, we identified adult females diagnosed with PBS between 2004 and 2013. The influence of insurance status on overall survival (OS) was evaluated using the Kaplan–Meier estimator with log-rank tests and Cox proportional hazard models. Among a cohort of 607 patients, 67 (11.0%) had Medicaid, 217 (35.7%) had Medicare, and 323 (53.2%) had private insurance. Compared to privately insured patients, Medicaid patients were more likely to present with larger tumors and have their first surgical procedure further after diagnosis. Treatment was similar between patients with comparable disease stage. In multivariate analysis, Medicaid (hazard ratio (HR), 2.47; 95% confidence interval (CI), 1.62–3.77;
Breast sarcomas are rare neoplasms that represent less than 5% of soft-tissue sarcomas and less than 1% of breast malignancies [
Management of rare cancers including breast sarcoma is challenging due to limited case numbers and lack of prospective clinical trials. Current recommendations for primary breast sarcoma are derived from small retrospective studies and extrapolated from the treatment of nonbreast soft-tissue sarcomas. Given the complexity of management and paucity of data, cases should be managed by multidisciplinary teams with expertise in sarcoma [
Health insurance coverage affects access to cancer care and has important clinical consequences. Insurance coverage influences whether patients undergo recommended cancer screening [
We performed a retrospective cohort study using the National Cancer Database (NCDB) 2014 Participant User File. This study was exempt from review by our institutional review board. The NCDB is a joint program of the Commission on Cancer (CoC) of the American College of Surgeons and the American Cancer Society (ACS) and is a hospital-based registry with data from more than 1,500 CoC-accredited hospitals. It includes information about demographics, disease stage, comorbidity, and the first course of treatment for 70% of newly diagnosed cancer cases in the United States. The CoC and American Cancer Society have not verified and are not responsible for the analytic or statistical methodology used or for the conclusions drawn from these data.
We identified female patients 18 years and older who were diagnosed with histologically confirmed malignant breast sarcoma in 2004–2013 (International Classification of Diseases for Oncology-3 (ICD-O-3) site C50.0–50.9; ICD-O-3 histology 8800, 8801, 8802, 8810, 8830, 8831, 8850, 8851, 8852, 8854, 8890, 8894, 8930, 8940, 8990, 9120, 9130, 9180, 9220, and 9580) [
Cohort selection.
No. | % | ||
---|---|---|---|
1 | Total breast cancer cases diagnosed from 2004 to 2014 | 2,246,280 | 100.00% |
2 | Limit to female patients 18 years and older with histologically confirmed primary invasive breast sarcoma diagnosed from 2004 to 2013 | 741 | 0.03% |
3 | Exclude patients whose diagnosis date precedes reference date to ensure data completeness | 723 | 0.03% |
4 | Exclude patients who were diagnosed at reporting facility but did not receive any treatment at that facility | 696 | 0.03% |
5 | Exclude patients with unknown vital status or unknown follow-up; exclude patients diagnosed at autopsy | 683 | 0.03% |
6 | Exclude if insurance status is unknown | 656 | 0.03% |
7 | Limit to patients with private, Medicaid, or Medicare insurance | 607 | 0.03% |
Relevant patient, facility, and tumor characteristics were obtained from the database (Table
Baseline patient and tumor characteristics by insurance coverage type.
Patient and tumor characteristics | Private | Medicaid | Medicare | |
---|---|---|---|---|
No. (%) | No. (%) | No. (%) |
| |
Totalb | 323 (53.2%) | 67 (11.0%) | 217 (35.7%) | — |
Age (years) | <0.001 | |||
18–44 | 95 (29.4%) | 20 (29.9%) | <11 | — |
45–54 | 101 (31.3%) | 29 (43.3%) | <11 | — |
55–64 | 97 (30.0%) | ≥11 | 13 (6.0%) | — |
≥65 | 30 (9.3%) | <11 | 192 (88.5%) | — |
Race | 0.001 | |||
White | 249 (77.1%) | 40 (59.7%) | 182 (83.9%) | — |
Black | 50 (15.5%) | ≥11 | ≥11 | — |
Other/unknown | 24 (7.4%) | <11 | <11 | — |
Year of diagnosis | 0.506 | |||
2004-2005 | 76 (23.5%) | ≥11 | 40 (18.4%) | — |
2006-2007 | 64 (19.8%) | <11 | 40 (18.4%) | — |
2008-2009 | 61 (18.9%) | 15 (22.4%) | 54 (24.9%) | — |
2010-2011 | 66 (20.4%) | 15 (22.4%) | 42 (19.4%) | — |
2012-2013 | 56 (17.3%) | 14 (20.9%) | 41 (18.9%) | — |
Charlson–Deyo score | <0.001 | |||
0 | 286 (88.5%) | ≥11 | 149 (68.7%) | — |
≥1 | 37 (11.5%) | <11 | 68 (31.3%) | — |
Residence type | 0.419 | |||
Metropolitan | 280 (86.7%) | 54 (80.6%) | 183 (84.3%) | — |
Urban/rural | 34 (10.5%) | 11 (16.4%) | 31 (14.3%) | — |
Incomec | 0.026 | |||
<$38,000 | 51 (15.8%) | 20 (29.9%) | 41 (18.9%) | — |
≥$38,000 | 269 (83.3%) | 45 (67.2%) | 175 (80.6%) | — |
Educational attainment (% without HSD)c | <0.001 | |||
≥13% | 130 (40.2%) | 43 (64.2%) | 88 (40.6%) | — |
<13% | 190 (58.8%) | 22 (32.8%) | 129 (59.4%) | — |
Facility locationd | <0.001 | |||
Northeast | 58 (18.0%) | ≥11 | 43 (19.8%) | — |
South | 87 (26.9%) | 15 (22.4%) | 76 (35.0%) | — |
Central | 58 (18.0%) | 15 (22.4%) | 61 (28.1%) | — |
West | 51 (15.8%) | <11 | ≥11 | — |
Unknown | 69 (21.4%) | 19 (28.4%) | <11 | — |
Facility cancer program typed | <0.001 | |||
Academic/researche | 101 (31.3%) | 21 (31.3%) | ≥11 | — |
Nonacademic | 153 (47.4%) | 27 (40.3%) | 152 (70.0%) | — |
Unknown | 69 (21.4%) | 19 (28.4%) | <11 | — |
Distance from facility | 0.087 | |||
≤50 miles | 289 (89.5%) | ≥11 | 198 (91.2%) | — |
>50 miles | 31 (9.6%) | <11 | 19 (8.8%) | — |
Angiosarcoma | 0.858 | |||
Yes | 111 (34.4%) | 21 (31.3%) | 71 (32.7%) | — |
No | 212 (65.6%) | 46 (68.7%) | 146 (67.3%) | — |
Stagef | 0.010 | |||
I/II | 193 (59.8%) | 25 (37.3%) | 114 (52.5%) | — |
III | 68 (21.1%) | 25 (37.3%) | 44 (20.3%) | — |
IV | 22 (6.8%) | <11 | 20 (9.2%) | — |
Unknown | 40 (12.4%) | <11 | 39 (18.0%) | — |
Tumor size category | <0.001 | |||
T1: ≤5 cm | 166 (51.4%) | ≥11 | 102 (47.0%) | — |
T2: >5 cm | 127 (39.3%) | 48 (71.6%) | 90 (41.5%) | — |
Unknown | 30 (9.3%) | <11 | 25 (11.5%) | — |
Node statusg | 0.435 | |||
N0 | 135 (41.8%) | 33 (49.3%) | 85 (39.2%) | — |
N+ | 11 (3.4%) | <11 | <11 | — |
No nodes examined/unknown | 177 (54.8%) | ≥11 | ≥11 | — |
Metastatic statush | 0.659 | |||
M0 | 284 (87.9%) | 55 (82.1%) | 183 (84.3%) | — |
M1 | 24 (7.4%) | <11 | 20 (9.2%) | — |
Unknown | 15 (4.6%) | <11 | 14 (6.5%) | — |
Grade | 0.096 | |||
G1: well differentiated | 58 (18.0%) | <11 | 29 (13.4%) | — |
G2: moderately differentiated | 44 (13.6%) | <11 | 22 (10.1%) | — |
G3: poorly/undifferentiated/anaplastic | 150 (46.4%) | 42 (62.7%) | 108 (49.8%) | — |
Unknown | 71 (22.0%) | 11 (16.4%) | 58 (26.7%) | — |
In order to protect patient identity, some categories are combined, unknown categories with few patients are not shown, and cells with fewer than 11 patients are hidden; aPearson’s chi-squared
The primary surgical procedure was categorized into no surgery, breast-conserving surgery (BCS), mastectomy without reconstruction, mastectomy with reconstruction, and mastectomy not otherwise specified (NOS). Treatment was defined as no definitive treatment, surgery alone, surgery and radiation therapy (RT), and other. The “other” category included patients who received chemotherapy alone, RT alone, chemotherapy and RT, or unknown. Additional characteristics are listed in Table
Baseline treatment characteristics by insurance coverage type.
Treatment Characteristics | Private | Medicaid | Medicare | |
---|---|---|---|---|
No. (%) | No. (%) | No. (%) |
|
|
Total | 323 (53.2%) | 67 (11.0%) | 217 (35.7%) | — |
Primary surgical procedure | <0.001 | |||
No surgery | 22 (6.8%) | <11 | 26 (12.0%) | — |
BCS | 111 (34.4%) | 16 (23.9%) | 49 (22.6%) | — |
Mastectomy without reconstruction | 124 (38.4%) | 27 (40.3%) | 91 (41.9%) | — |
Mastectomy with reconstruction | 32 (9.9%) | <11 | <11 | — |
Mastectomy NOS | 32 (9.9%) | 19 (28.4%) | ≥11 | — |
Surgical margins | 0.217 | |||
Negative | 272 (84.2%) | 58 (86.6%) | 171 (78.8%) | — |
Positiveb | 18 (5.6%) | <11 | 13 (6.0%) | — |
NA/unknown | 33 (10.2%) | <11 | 33 (15.2%) | — |
Receipt of RT | 0.004 | |||
No | 188 (58.2%) | 33 (49.3%) | 150 (69.1%) | — |
Yes | 131 (40.6%) | 31 (46.3%) | 66 (30.4%) | — |
Receipt of chemotherapy | 0.021 | |||
No | 221 (68.4%) | 43 (64.2%) | 173 (79.7%) | — |
Yes | 94 (29.1%) | 23 (34.3%) | 39 (18.0%) | — |
Treatment | <0.001 | |||
No definitive tx | 12 (3.7%) | <11 | 17 (7.8%) | — |
Surgery alone | 124 (38.4%) | 22 (32.8%) | 112 (51.6%) | — |
Surgery and RT | 126 (39.0%) | 31 (46.3%) | 60 (27.6%) | — |
Otherc | 61 (18.9%) | ≥11 | 28 (12.9%) | — |
Median (IQR) | Median (IQR) | Median (IQR) |
| |
Days from diagnosis to surgery | 15.0 (0.0, 33.0) | 27.5 (8.0, 44.0) | 19.0 (0.0, 35.0) | 0.017 |
In order to protect patient identity, some categories are combined, unknown categories with few patients are not shown, and cells with fewer than 11 patients are hidden; aPearson’s chi-squared
Pearson chi-square tests were used to determine associations between insurance type and demographic, tumor, and treatment characteristics. Wilcoxon and Kruskal–Wallis tests were used to compare median age and time from diagnosis to first surgical procedure between insurance types. Differences in overall survival, defined as time to death or last contact after diagnosis, were assessed using the Kaplan–Meier estimator with log-rank testing. Univariate and multivariate Cox proportional hazard models were used to evaluate the impact of insurance type on survival. Covariates in the multivariate model were selected a priori and included insurance type, age, race, year of diagnosis, comorbidity score, income, residence environment type, distance from reporting facility, educational attainment, angiosarcoma histology, tumor size, lymph node status, metastatic status, grade, and treatment. All tests were two-sided with an alpha value of 0.05. Statistical analyses were performed using STATA/SE software (version 14.0, StataCorp, College Station, TX).
We identified 607 patients who met our inclusion criteria (Table
Medicaid and privately insured patients were similar in age (median 50 and 52 years, resp.) and younger than Medicare patients (median 76 years). Medicaid-insured patients were more likely to be black and live in zip codes with lower median household income and educational attainment. Medicaid patients were less likely to have comorbid conditions and more likely to have large tumors, with 31.3% of Medicaid patients presenting with tumors greater than 10 cm in size.
Baseline treatment characteristics are presented in Table
Medicaid-insured patients were more likely to undergo surgery, radiation, and chemotherapy. Receipt of RT was not significantly different between Medicaid and privately insured patients presenting with high-grade tumors (42.9% versus 51.3%, resp.;
Median follow-up time from the date of diagnosis to the date of death or last contact was 42 months (interquartile range (IQR), 21 to 77 months), 27 months (IQR, 12 to 48 months), and 7 months (IQR, 3 to 13 months) for stage I/II (Figure
Kaplan–Meier plots of overall survival stratified by insurance coverage type (private insurance, Medicaid, and Medicare) for patients with (a) stage I/II, (b) stage III, and (c) stage IV primary breast sarcomas.
On univariate analysis, Medicaid and Medicare insurance were associated with increased hazard of death compared to private insurance (Table
Univariate and multivariate Cox proportional hazard models.
Variable | Univariate analysis | Multivariate analysis | ||
---|---|---|---|---|
HR (95% CI) |
|
HR (95% CI) |
|
|
Insurance coverage | ||||
Private | Reference | Reference | ||
Medicaid | 3.01 (2.04–4.45) | <0.001 | 2.47 (1.62–3.77) | <0.001 |
Medicare | 2.55 (1.94–3.33) | <0.001 | 1.68 (1.10–2.57) | 0.017 |
Age (years) | ||||
18–44 | Reference | Reference | ||
45–54 | 1.34 (0.87–2.06) | 0.187 | 1.20 (0.76–1.89) | 0.435 |
55–64 | 1.34 (0.86–2.08) | 0.194 | 1.52 (0.95–2.43) | 0.081 |
≥65 | 2.40 (1.65–3.50) | <0.001 | 2.03 (1.20–3.43) | 0.008 |
Race | ||||
White | Reference | Reference | ||
Black | 0.90 (0.63–1.27) | 0.543 | 0.65 (0.43–0.98) | 0.040 |
Other/unknown | 0.43 (0.23–0.81) | 0.009 | 0.45 (0.24–0.87) | 0.018 |
Year of diagnosis | ||||
2004-2005 | Reference | Reference | ||
2006-2007 | 0.80 (0.54–1.18) | 0.256 | 0.70 (0.47–1.06) | 0.095 |
2008-2009 | 1.31 (0.92–1.87) | 0.130 | 1.04 (0.71–1.51) | 0.843 |
2010-2011 | 1.27 (0.87–1.86) | 0.220 | 0.68 (0.44–1.03) | 0.066 |
2012-2013 | 0.94 (0.60–1.49) | 0.802 | 0.74 (0.46–1.18) | 0.207 |
Charlson–Deyo score | ||||
0 | Reference | Reference | ||
1 | 1.19 (0.86–1.66) | 0.291 | 1.13 (0.77–1.63) | 0.535 |
≥2 | 3.28 (1.67–6.42) | 0.001 | 1.40 (0.68–2.92) | 0.363 |
Income | ||||
<$38,000 | Reference | Reference | ||
≥$38,000 | 0.77 (0.57–1.05) | 0.099 | 0.95 (0.65–1.39) | 0.795 |
Residence type | ||||
Metropolitan | Reference | Reference | ||
Urban/rural | 1.21 (0.85–1.72) | 0.282 | 1.01 (0.67–1.53) | 0.956 |
Distance from facility | ||||
≤50 miles | Reference | Reference | ||
>50 miles | 0.93 (0.61–1.43) | 0.741 | 0.72 (0.45–1.16) | 0.179 |
Educational attainment (% without HSD) | ||||
≥13% | Reference | Reference | ||
<13% | 0.87 (0.67–1.11) | 0.255 | 0.89 (0.66–1.19) | 0.415 |
Angiosarcoma | ||||
Yes | Reference | Reference | ||
No | 0.96 (0.74–1.24) | 0.755 | 0.82 (0.62–1.10) | 0.183 |
Tumor size category | ||||
T1: ≤5 cm | Reference | Reference | ||
T2: >5 cm | 3.26 (2.47–4.30) | <0.001 | 3.66 (2.66–5.02) | <0.001 |
Unknown | 1.72 (1.08–2.74) | 0.022 | 1.56 (0.95–2.54) | 0.079 |
Node status | ||||
N0 | Reference | Reference | ||
N+ | 1.54 (0.75–3.16) | 0.239 | 1.43 (0.67–3.06) | 0.348 |
No nodes examined/unknown | 0.98 (0.76–1.26) | 0.880 | 0.92 (0.70–1.23) | 0.586 |
Metastatic status | ||||
M0 | Reference | Reference | ||
M1 | 7.20 (5.19–10.00) | <0.001 | 7.19 (4.69–11.03) | <0.001 |
Grade | ||||
G1: well differentiated | Reference | Reference | ||
G2: moderately differentiated | 1.36 (0.78–2.38) | 0.280 | 1.49 (0.83–2.69) | 0.181 |
G3: poorly, undifferentiated, or anaplastic | 2.67 (1.74–4.12) | <0.001 | 2.23 (1.39–3.58) | 0.001 |
Unknown | 2.04 (1.25–3.30) | 0.004 | 1.89 (1.14–3.13) | 0.014 |
Treatment summary | ||||
No definitive treatment | Reference | Reference | ||
Surgery alone | 0.31 (0.18–0.53) | <0.001 | 0.20 (0.11–0.37) | <0.001 |
Surgery and RT | 0.27 (0.15–0.47) | <0.001 | 0.12 (0.06–0.23) | <0.001 |
Other/unknown | 0.60 (0.34–1.07) | 0.083 | 0.22 (0.11–0.43) | <0.001 |
Abbreviations: HR, hazard ratio; CI, confidence interval; HSD, high school degree; RT, radiation therapy.
Our findings did not change when we created another model additionally adjusting for facility type, thereby excluding patients aged below 40 years; Medicaid and Medicare patients again had worse survival outcomes compared to privately insured patients. Treatment at nonacademic facility type was associated with worse OS relative to treatment at an academic facility (HR, 1.52; 95% CI, 1.12–2.07;
To evaluate whether the impact of insurance on outcomes was greater among patients with a rare cancer like breast sarcoma compared to breast carcinoma, we constructed another model that included patients with breast carcinoma to look at the interaction between cancer type (breast sarcoma versus breast carcinoma) and insurance category (Medicaid versus private) (Table
Multivariate Cox proportional hazard models of the effect of insurance status on overall survival in patients with breast sarcoma versus carcinoma.
Multivariate analysisa | ||
---|---|---|
HR (95% CI) |
|
|
Interaction between insurance status and breast cancer typeb | ||
Medicaid versus private; sarcoma versus carcinoma | — | <0.001 |
Medicare versus private; sarcoma versus carcinoma | — | 0.912 |
Breast cancer type | ||
Carcinoma: Medicaid versus private (reference) | 1.69 (1.66–1.72) | <0.001 |
Sarcoma: Medicaid versus private (reference) | 2.48 (1.63–3.78) | <0.001 |
aAdjusted for age, race, year of diagnosis, comorbidity, income, location, distance from treatment facility, educational attainment, tumor size, node status, metastatic status, tumor grade, and treatment; b
Using a nationwide database of women with primary breast sarcoma (PBS), we found that patients who were privately insured had better survival than those who had nonprivate insurance. We also found that the Medicaid-related health disparity was greater in the setting of a rare cancer.
Our findings contribute to the growing literature highlighting the importance of insurance status in cancer outcomes and quality of care. While previous studies have explored the relationship between insurance status and outcomes in other common cancers including breast cancer [
There are many factors that could lead to worse outcomes in Medicaid patients ranging from the consequences of Medicaid insurance policies to the socioeconomic factors driving patients to be insured by Medicaid. While insurance coverage reduces disparities in cancer outcomes, it does not completely eliminate the effects of social determinants of health such as race and socioeconomic status [
We found that Medicaid-insured patients with breast sarcoma were more likely to present with large, advanced stage tumors. This association builds upon previous studies that have found that patients with nonprivate insurance have an increased likelihood of presenting with advanced breast, prostate, lung, colorectal, head and neck, liver, and pancreatic cancers compared to those with private insurance [
Commensurate with more advanced stage tumors, Medicaid patients underwent more aggressive locoregional management of PBS. However, privately insured and Medicaid-insured patients with comparable disease stage received similar treatment. Many Medicaid patients were likely ineligible for breast-conserving surgery (BCS) due to presentation with very large (>10 cm) tumors. We found similar rates of BCS among privately insured and Medicaid-insured patients with stage I/II disease. Receipt of radiation therapy (RT) was also similar between privately insured and Medicaid-insured patients undergoing lumpectomy or presenting with large or high-grade tumors. Given the similarity in treatment, presentation with advanced disease may be a more important driver of poor outcomes in Medicaid patients.
After adjusting for sociodemographic, tumor, and treatment characteristics, Medicaid and Medicare patients continued to have worse outcomes than privately insured patients. Furthermore, the health disparity associated with Medicaid insurance was significantly worse in patients with breast sarcoma versus breast carcinoma. Medicaid insurance may be a greater challenge for patients with rare cancers because of limited access to centers with specialists [
Access to specialists and insurance network adequacy is a concern among patients who have Medicaid insurance. Medicaid-managed care plans can limit access to providers and “off-label” drugs, including chemotherapies [
Medicare insurance did not differentially impact outcomes in breast sarcoma compared to breast carcinoma. This may suggest that the survival detriment associated with Medicare is related to the agedness and higher comorbidity of Medicare patients more than the healthcare access issues that might be worse with a rare cancer. Medicare patients have better access to care and higher provider reimbursements than Medicaid patients do. Consistent with this, Medicare patients have been shown to benefit from improved cancer treatment and survival over time, while survival disparities are worsening for Medicaid patients [
In this study, treatment at academic and NCI-designated cancer centers was independently associated with better overall survival in a subset of patients with available facility type. While we did not find that privately insured patients were more likely to be treated at academic centers, our analysis is limited by the large percentage of patients with unknown treatment facility type, which the NCDB suppresses for patients aged below 40 years for privacy reasons. Additionally, we were unable to distinguish NCI-designated comprehensive cancer centers from academic centers, which represent the majority of safety net hospitals caring for the underinsured [
Our finding of worse outcomes in Medicaid-insured patients does not necessarily suggest that Medicaid itself is inferior to private insurance because Medicaid is designed to cover poorer patients who tend to have more advanced disease. Almost half of the Medicaid beneficiaries with cancer enroll in Medicaid after they are diagnosed with cancer when they already have advanced disease [
Our study has multiple limitations including its retrospective design and reliance on the content and accuracy of data included in the NCDB. While we attempted to control for observed confounders, we could not control for unmeasured confounders such as baseline performance status, patient preference, and molecular data. Additionally, we were unable to account for the clinical heterogeneity of sarcomas, which exists even among tumors of the same histologic subtype [
In conclusion, we show that privately insured patients with PBS present with earlier stage disease and have better outcomes. Further work is warranted to address the cultural and socioeconomic factors that lead to such health disparities.
Julie L. Koenig and C. Jillian Tsai are co-first authors.
The authors declare that there are no conflicts of interest regarding the publication of this article.
The project described was supported by the Memorial Sloan-Kettering Cancer Center Support Grant (P30 CA008748-50).