DEMOGRAPHIC DISPARITIES IN THE MANAGEMENT OF LOBULAR CARCINOMA IN SITU OF THE BREAST

Background: Lobular carcinoma in situ (LCIS) of the breast has been shown to be a marker for an increased risk of breast cancer, rather than an actual carcinoma. There are several recommended options for the management of LCIS: observation alone, chemoprevention using Tamoxifen, and prophylactic mastectomy. It is unclear how demographic factors such as age, race and insurance type are associated with the type of management received; specifically, whether surgery was received and the type of surgery received. Therefore, the aim of this study was to identify whether demographic disparities exist in the management of LCIS and to quantify the risk associated with such disparities. Specifically, we sought to assess whether race-related differences exist in whether a person with LCIS received no surgery, partial mastectomy or complete mastectomy. Of secondary interest was to assess whether age and insurance-related differences exist in whether a person with LCIS received no surgery, partial mastectomy or complete mastectomy. Methods: The Surveillance, Epidemiology and End Results (SEER) database was used to obtain information on patients diagnosed with LCIS between 2005 and 2014. Patients were stratified by race, and racial differences in variables related to clinical features and treatment were assessed. Descriptive statistics were calculated; Chi-square tests compared categorical variables and one-way ANOVA compared group means for continuous variables. To assess whether age was an effect modifier of the association between race and type of treatment received, a multinomial logistic regression model was run including the interaction or product term of race*age. Similarly, to assess whether insurance type was an effect modifier of the association between race and type of treatment received, a multinomial logistic regression model was run including the interaction or product term of race*insurance type. Age was considered an effect modifier, and thus multinomial logistic regression was performed with the study sample stratified by age category. To assess whether a variable was a confounder of the association between race and treatment type, stratified multinomial logistic regression was performed with each variable in question independently added as a covariate to the stratified analyses. The crude odds ratio was compared to the odds ratio adjusted for the variable in question. If the odds ratios differed by more than 10%, the variable in question was considered a confounder. No variable acted as a confounder. Thus, no covariates were added to the model for adjustment. In the final model, multinomial logistic regression with stratification by age category was performed to assess the association between race and treatment type (i.e., no surgery, partial mastectomy, or complete mastectomy), and calculate relative risk ratios (RRR) that reflected the likelihood of receiving a particular treatment for each racial group. Although insurance type did not appear to act as an effect modifier or confounder, another stratified multinomial logistic regression model was run that included insurance type as a covariate in order to assess whether insurance type had any impact at all on the association between race and treatment type. A p-value of < 0.05 was used to determine significance for all statistical tests, and 95% confidence intervals were used for logistic models. Results: The study sample (N=16,646) was 75.6% non-Hispanic white, 8.0% non-Hispanic Black, 9.3% Hispanic, 5.1% non-Hispanic Asian, and 2.1% other/unknown. White patients were older (mean age 55.4 years versus 54.9 years for Blacks, 52.0 years for Hispanics, and 51.4 years for Asians; p < 0.001). A greater proportion of whites and Asians were insured than Blacks and Hispanics (73.9% for whites and 77.0% for Asians versus 66.5% for Blacks, and 66.0% for Hispanics; p < 0.001). The predominant treatment type was partial mastectomy for all races. However, a greater proportion of whites underwent complete mastectomy compared to other races (22.8% versus 15.5% for Blacks, 19.3% for Hispanics, and 16.9% for Asians; p < 0.001). Among patients 65 – 74 years, Blacks were less likely to undergo partial mastectomy than no surgery compared to whites (RRR = 0.61, 95% CI 0.40 – 0.95). Moreover, Blacks in all but the youngest age group were less likely to undergo complete mastectomy than no surgery compared to whites (RRR range: 0.35 – 0.48). There were no significant differences in the type of treatment received among Hispanics. In all age groups, patients of other/unknown race were significantly less likely to undergo partial (RRR range: 0.02 –0.14) or complete mastectomy (RRR range: 0.19 – 0.28) than no surgery compared to whites. There were less consistent findings for other race and age strata. Asians were more likely to undergo partial mastectomy than no surgery compared to whites if they were aged 45 – 54 years (RRR = 1.57, 95% CI 1.03 – 2.41). But Asians were less likely to undergo complete mastectomy than no surgery compared to whites if they were aged 55 – 64 years (RRR = 0.48, 95% CI 0.26 – 0.92). In the additional stratified multinomial logistic regression model that included insurance type as a covariate, racial differences in treatment were also noted and results were similar to those reported above for the unadjusted model. Conclusion: A larger proportion of white women had complete mastectomy compared to all other racial groups. While there were significant racial differences in socioeconomic variables in descriptive analyses, they did not confound the relationship between race and treatment of patients with LCIS. Racial differences in treatment were most significant among patients who were Black or of other/unknown race and the association was modified by age. Further research into factors affecting the decision to proceed with surveillance or surgery, as well as reasons behind the disparity in treatment among certain racial groups is warranted.

Grantor dc:publisher

Temple University. Libraries

Year dc:date.issued

2018

Author dc:creator

• Moten, Ambria

Advisor dc:contributor.advisor

• Jones, Resa M.

Committee member dc:contributor.committeemember

• Coffman, Donna L.

• Medicine

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• IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/20.500.12613/3312

OAI identifier oai:identifier

oai:scholarshare.temple.edu:20.500.12613/3312