Treatment patterns for ductal carcinoma in situ from 2000-2010 across six integrated health plans

Factors associated with ductal carcinoma in situ (DCIS) treatment patterns and patient-reported outcomes across a large integrated health network

PURPOSE

To examine associations between ductal carcinoma in situ (DCIS) patients' characteristics, treating locations and DCIS treatments received and to pilot assessing quality-of-life (QoL) values among DCIS patients with diverse backgrounds.

METHODS

We performed a retrospective tumor registry review of all patients diagnosed and treated with DCIS from 2018 to 2019 in the UPMC-integrated network throughout central and western Pennsylvania. Demographics, clinical information, and administered treatments were compiled from tumor registry records. We categorized contextual factors such as different hospital setting (academic vs. community), socioeconomic status based on the neighborhood deprivation index (NDI) as well as age and race. QoL survey was administered to DCIS patients with diverse backgrounds via QoL questionnaire breast cancer module 23 and qualitative assessment questions.

RESULTS

A total of 912 patients were reviewed. There were no treatment differences noted for age, race, or NDI. Mastectomy rate was higher in academic sites than community sites (29 vs. 20.4%; p = 0.0045), while hormone therapy (HT) utilization rate was higher in community sites (74 vs. 62%; p = 0.0012). QoL survey response rate was 32%. Only HT side effects negatively affected in QoL scores and there was no significant difference in QoL domains and decision-making process between races, age, NDI, treatment groups, and treatment locations.

CONCLUSION

Our integrated health network did not show chronically noted disparities arising from social determinates of health for DCIS treatments by implementing clinical pathways and system-wide peer review. Also, we demonstrated feasibility in collecting QoL for DCIS women with diverse backgrounds and different socioeconomic statuses.

Factors influencing the initiation of adjuvant endocrine therapy in patients with estrogen receptor-positive ductal carcinoma in situ: a single institution experience

Purpose

This study evaluates whether race, socioeconomic status, insurance type, oncological provider type, and prior cancer treatment are associated with the suggestion and acceptance of hormonal therapy in patients with estrogen receptor (ER)-positive Ductal carcinoma in situ (DCIS). This study also assesses whether disparities exist pertaining to prescription of such medications.

Methods

This single-center retrospective study included 111 patients diagnosed with DCIS between 2020 and 2021. Data collected included race, type of insurance, prescribing providers, and socioeconomic status. We used zip codes to identify the poverty levels in these areas as published in the United States Census Bureau and stratified the patients into quartiles accordingly. Chi-Square statistics were used to calculate significance levels.

Results

There was no significant correlation between the intake of hormonal therapy and race (p = 0.60), insurance (p = 0.50), socioeconomic (p = 0.58), or providers (p = 0.99). 79.3% of women were offered endocrine therapy. Of those who were offered endocrine therapy, 70.8% accepted. Of patients not on hormonal therapy, 45.8% were not recommended the medications by their provider, and 54.2% declined treatment when offered.

Conclusion

In this study, patients’ demographics and providers were not associated with adjuvant hormonal therapy initiation in DCIS. Our results show that abstaining from endocrine therapy in DCIS patients is both due to lack of provider recommendation and patient rejection of these medications. The wide variation in hormonal therapy treatment among ER-positive DCIS patients suggests a need for improved provider-patient communication regarding the risks and benefits of endocrine therapy in order to ensure a shared decision-making process.

Rural-urban differences in secular trends of locoregional treatment for ductal carcinoma in situ: A patterns of care analysis

Precis

Omission of PORT following BCS remains high among rural patients despite evidence that PORT leads to a significant reduction in the risk of local recurrence. Further research is needed to examine the impact of rural residence on treatment choices and develop methods to ensure equitable care among all breast cancer patients.

Background

Despite national guidelines, debate exists among clinicians regarding the optimal approach to treatment for patients diagnosed with ductal carcinoma in situ (DCIS). While regional variation in practice patterns has been well documented, population‐based information on rural–urban treatment differences is lacking.

Methods

Data from the SEER Patterns of Care studies were used to identify women diagnosed with histologically confirmed DCIS who underwent cancer‐directed surgery in the years 1991, 1995, 2000, 2005, 2010, and 2015. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated using weighted multivariable logistic regression to evaluate cancer‐directed surgery and use of post‐operative radiation therapy (PORT).

Results

Of the 3337 patients who met inclusion criteria, 27% underwent mastectomy, 26% underwent breast‐conserving surgery (BCS) without PORT, and 47% underwent BCS with PORT. After adjustment for other covariates, there was no difference in the likelihood of receiving mastectomy between rural and urban patients (aOR = 0.65; 95% CI 0.37–1.14). However, rural residents were more likely than urban residents to have mastectomy during 1991/1995 (aOR = 1.78; 95% CI 1.09–2.91; p_interaction = 0.022). Across all diagnosis years, patients residing in rural areas were less likely to receive PORT following BCS compared to urban patients (aOR = 0.35; 95% CI 0.18–0.67).

Conclusions

Omission of PORT following BCS remains high among rural patients despite evidence that PORT leads to a significant reduction in the risk of local recurrence. Further research is needed to examine the impact of rural residence on treatment choices and develop methods to ensure equitable care among all breast cancer patients.

Validation of a Ductal Carcinoma In Situ Biomarker Profile for Risk of Recurrence after Breast-Conserving Surgery with and without Radiotherapy

PURPOSE

A major challenge in ductal carcinoma in situ (DCIS) treatment is selection of the most appropriate therapeutic approach for individual patients. We conducted an external prospective-retrospective clinical validation of a DCIS biologic risk signature, DCISionRT, in a population-based observational cohort of women diagnosed with DCIS and treated with breast-conserving surgery (BCS).

EXPERIMENTAL DESIGN

Participants were 455 health plan members of Kaiser Permanente Northwest diagnosed with DCIS and treated with BCS with or without radiotherapy from 1990 to 2007. The biologic signature combined seven protein tumor markers assessed in formalin-fixed, paraffin-embedded tumor tissue with four clinicopathologic factors to provide a DCISionRT test result, termed decision score (DS). Cox regression and Kaplan-Meier analysis were used to measure the association of the DS, continuous (linear) or categorical (DS ≤ 3 vs. DS > 3), and subsequent total ipsilateral breast events and invasive ipsilateral breast events at least 6 months after initial surgery.

RESULTS

In Cox regression, the continuous and categorical DS variables were positively associated with total and invasive breast event risk after adjustment for radiotherapy. In a subset analysis by treatment group, categorical Kaplan-Meier analyses showed at least 2-fold differences in 10-year risk of total breast events between the elevated-risk and low-risk DS categories.

CONCLUSIONS

In this first external validation study of the DCISionRT test, the DS was prognostic for the risk of later breast events for women diagnosed with DCIS, following BCS.

Association of Magnetic Resonance Imaging and a 12-Gene Expression Assay With Breast Ductal Carcinoma In Situ Treatment

IMPORTANCE

Advanced diagnostics, such as magnetic resonance imaging (MRI) and gene expression profiles, are potentially useful to guide targeted treatment in patients with ductal carcinoma in situ (DCIS).

OBJECTIVES

To examine the proportion of patients who converted to mastectomy after MRI and the reasons for those conversions and to measure patient adherence to radiotherapy guided by the 12-gene DCIS score.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of a prospective, cohort, nonrandomized clinical trial that enrolled women with DCIS on core biopsy who were candidates for wide local excision (WLE) from 75 institutions from March 25, 2015, to April 27, 2016, through the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network trial E4112.

INTERVENTIONS

Participants underwent breast MRI before surgery, and subsequent management incorporated MRI findings for choice of surgery. The DCIS score was used to guide radiotherapy recommendations among women with DCIS who had WLE as the final procedure and had tumor-free excision margins of 2 mm or greater.

MAIN OUTCOMES AND MEASURES

The primary end point was to estimate the conversion rate to mastectomy and the reason for conversion.

RESULTS

Of 339 evaluable women (mean [SD] age, 59.1 [10.1] years; 262 [77.3%] of European descent) eligible for WLE before MRI, 65 (19.2%; 95% CI, 15.3%-23.7%) converted to mastectomy. Of these 65 patients, conversion was based on MRI findings in 25 (38.5%), patient preference in 25 (38.5%), positive margins after attempted WLE in 10 (15.4%), positive genetic test results in 3 (4.6%), and contraindication to radiotherapy in 2 (3.1%). Among the 285 who had WLE performed after MRI as the first surgical procedure, 274 (96.1%) achieved successful breast conservation. Of 171 women eligible for radiotherapy guided by DCIS score (clear margins, absence of invasive disease, and score obtained), the score was low (<39) in 82 (48.0%; 95% CI, 40.6%-55.4%) and intermediate-high (≥39) in 89 (52.0%; 95% CI, 44.6%-59.4%). Of these 171 patients, 159 (93.0%) were adherent with recommendations.

CONCLUSIONS AND RELEVANCE

Among women with DCIS who were WLE candidates based on conventional imaging, multiple factors were associated with conversion to mastectomy. This study may provide useful preliminary information required for designing a planned randomized clinical trial to determine the effect of MRI and DCIS score on surgical management, radiotherapy, overall resource use, and clinical outcomes, with the ultimate goal of achieving greater therapeutic precision.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02352883.

Treatment patterns for ductal carcinoma in situ with close or positive mastectomy margins

BACKGROUND

Mastectomy remains an effective treatment for ductal carcinoma in situ (DCIS) but whether further therapy is warranted for close or positive margins is controversial. We aim to characterize the treatment practices of DCIS throughout the United States in patients who undergo mastectomy with close or positive margins to better understand the use of postmastectomy radiation therapy (PMRT).

MATERIALS AND METHODS

Using the 2004-2013 National Cancer Database, we identified all female patients with a diagnosis of DCIS who underwent mastectomy. Distributional characteristics were summarized for overall and margin-stratified samples. Characteristic differences were assessed by region and receipt of radiation. Chi-square and independent sample t-tests were used to assess differences for categorical and continuous variables, respectively.

RESULTS

In 21,591 patients who met inclusion criteria, 470 patients with close/positive margins were identified. Sixteen percent of patients with close/positive margins received PMRT compared to 1.5% with negative margins (P < 0.01). There was no difference in PMRT and patient race, insurance status, treatment facility, or endocrine therapy. Patients with close/positive margins who received PMRT were more likely to be in an urban setting from the Midwest (24.6%) and Northeast (21.8%) compared to the West (11.0%) and South (10.7%) (P < 0.01).

CONCLUSIONS

Use of PMRT for DCIS following mastectomy with close/positive margins differs across the country. Regional variations in treatment patterns reinforce a need to determine whether PMRT improves survival to establish treatment guidelines.

Prescribing practices of endocrine therapy for ductal carcinoma in situ in British Columbia

Purpose

The mainstay of treatment for ductal carcinoma in situ (dcis) involves surgery in the form of mastectomy or lumpectomy. Inconsistency in the use of endocrine therapy (et) for dcis is evident worldwide. We sought to assess the variation in et prescribing for patients with dcis across a population-based radiotherapy (rt) program and to identify variables that predict its use.

Methods

Data from a breast cancer database were obtained for women diagnosed with dcis in British Columbia from 2009 to 2014. Associations between et use and patient characteristics were assessed by chi-square test and multilevel multivariate logistic regression. The Kaplan-Meier method, with propensity score matching and Cox regression analysis, was used to assess the effects of et on overall survival (os) and relapse-free survival (rfs).

Results

For the 2336 dcis patients included in the study, et use was 13% in dcis patients overall, and 17% in patients with estrogen receptor-positive (er+) tumours treated with breast-conserving surgery and rt. Significant variation in et use by treatment centre was observed (range: 8%-23%; p < 0.001), and prescription of et by individual oncologists varied in the range 0%-40%. After controlling for confounding factors, age less than 50 years [odds ratio (or): 1.72; p = 0.01], treatment centre, er+ status (or: 5.33; p < 0.001), and rt use (or: 1.77; p < 0.001) were significant predictors of et use. No difference in os or rfs with the use of et was observed.

Conclusions

In this population-based analysis, 13% of patients with dcis in British Columbia received et, with variation by treatment centre (8%-23%) and individual oncologist (0%-40%). Age less than 50 years, er+ status, and rt use were most associated with et use.

Endocrine Therapy Initiation among Older Women with Ductal Carcinoma In Situ

BACKGROUND

Although treatment of ductal carcinoma in situ (DCIS) is controversial, national guidelines recommend considering endocrine therapy for women with estrogen receptor- (ER-) positive DCIS or those undergoing breast conserving surgery (BCS) without radiation. We evaluated uptake and predictors of endocrine therapy use among older women with DCIS.

METHODS

In the SEER-Medicare database, we identified women aged 65+ years diagnosed with DCIS during 2007-2011. We evaluated demographic, tumor, and treatment characteristics associated with endocrine therapy initiation.

RESULTS

Among 2,945 women with DCIS, 41% initiated endocrine therapy (66% tamoxifen, 34% aromatase inhibitors). Initiation was more common among women with ER-positive than ER-negative DCIS (48% versus 16%; HR = 3.75, 95% CI: 2.91-4.83); 28% of women with unknown ER status initiated endocrine therapy. Initiation was less common after BCS alone compared to BCS with radiation (32% versus 50%; HR = 0.69, 95% CI: 0.59-0.80).

CONCLUSIONS

Less than half of older women with DCIS initiate endocrine therapy to prevent second breast cancers. Our findings suggest use was more common, but not exclusive, among women with ER-positive DCIS, but not among women who underwent BCS alone. Endocrine therapy should be targeted toward patients most likely to benefit from its use.

Tamoxifen Acceptance and Adherence among Patients with Ductal Carcinoma In Situ (DCIS) Treated in a Multidisciplinary Setting

Tamoxifen and other endocrine agents have proven benefits for women with ductal carcinoma in situ (DCIS), but low patient acceptance is widely reported. We examined factors associated with tamoxifen acceptance and adherence among DCIS patients who received a recommendation for therapy in a multidisciplinary setting. Using our institutional database, we identified women diagnosed with DCIS, 1998 to 2009, who were offered tamoxifen. We recorded data on demographics, tumor and therapy variables, tamoxifen acceptance, and adherence to therapy for ≥4 years. Univariable and multivariable analyses were conducted using logistic regression to identify factors specific to each group that were related to acceptance and adherence. A total of 555 eligible women identified, of whom 369 were offered tamoxifen; 298 (81%) accepted, among whom 214 (72%) were adherent, 59 of 298 (20%) were nonadherent, and for 25 (8%), adherence was undetermined. After stepwise elimination in adjusted logistic regression models, acceptance of breast radiotherapy was associated with acceptance of tamoxifen [OR, 2.22; 95% confidence interval (CI), 1.26-3.90; P < 0.01], as was a medical oncology consultation (OR, 1.76; 95% CI, 0.99-3.15; P = 0.05). Insured patients were more likely to adhere to tamoxifen (OR, 6.03; 95% CI, 2.60-13.98; P < 0.01). The majority of nonadherent women (n = 38/56, 68%) discontinued the drug during the first year of treatment with 48 (86%) citing adverse effect(s) as the reason. In a multidisciplinary, tertiary care setting, we observed relatively high rates of acceptance and adherence of tamoxifen. Acceptance of tamoxifen and radiotherapy were associated, and adherence was influenced by insurance status.Key Message: Tamoxifen acceptance and adherence following resection of DCIS of the breast is related to acceptance of radiotherapy and may be improved by confirmation of the recommendation by a medical oncologist. Despite the low cost of tamoxifen, adherence to therapy is significantly impacted by lack of insurance; those who discontinue therapy report adverse effects as a major reason. Cancer Prev Res; 10(7); 389-97. ©2017 AACR.

Endocrine Therapy Initiation and Medical Oncologist Utilization Among Women Diagnosed with Ductal Carcinoma in Situ

BACKGROUND

Though randomized clinical trials have demonstrated a reduction in second breast events with endocrine therapy among women with ductal carcinoma in situ (DCIS), use of these therapies remains highly variable. The purpose of this study was to evaluate patient and treatment-related factors associated with endocrine therapy initiation and medical oncology specialty utilization after DCIS.

MATERIALS AND METHODS

We identified women with a DCIS diagnosis during 2006-2010 in the North Carolina Central Cancer Registry with linked public and private insurance claims in the University of North Carolina Integrated Cancer Information Surveillance System data resource. Multivariable generalized linear regression models were used to estimate risk ratios (RR) and 95% confidence intervals (CI) for endocrine therapy initiation in the year following DCIS diagnosis.

RESULTS

Among 2,090 women with a DCIS diagnosis, 37% initiated endocrine therapy. Initiation was less common among women aged 75+ at diagnosis (RR = 0.79; 95% CI: 0.64-0.97 vs. age 45-54) and women treated with breast-conserving surgery (BCS) who did not receive radiation (RR = 0.63; 95% CI: 0.50-0.78 vs. BCS plus radiation). Consultation with a medical oncologist was strongly associated with endocrine therapy initiation (RR = 1.40; 95% CI: 1.23-1.61). Women who saw a medical oncologist more often had private insurance, higher census tract-level income, hormone receptor positive disease, and treatment with BCS and radiation.

CONCLUSION

Treatment strategies for DCIS remain controversial. Our data suggest that endocrine therapy is more often used in addition to standard therapies such as BCS plus radiation, rather than as an alternative to radiation. The Oncologist 2017;22:535-541 IMPLICATIONS FOR PRACTICE: Randomized trials have demonstrated a reduction in second breast cancer events with use of endocrine therapy for ductal carcinoma in situ (DCIS). However, notable variation exists in the uptake of these therapies among DCIS patients. In this study, factors associated with endocrine therapy initiation in the year following a DCIS diagnosis included consultation with a medical oncologist and treatment with breast-conserving surgery with radiation. Our findings help to explain the wide variation in endocrine therapy initiation and suggest the need for clear guidelines in the treatment of DCIS.

Effect of Patient Age on Outcomes in Breast Reconstruction: Results from a Multicenter Prospective Study

BACKGROUND

Although >40% of new breast cancer diagnoses in the US are in older women, few studies have assessed the outcomes of post-mastectomy reconstruction in this population. Our objective was to evaluate age effects on postoperative complications and patient-reported outcomes in women undergoing breast reconstruction, and to investigate whether age effects differ between reconstructive procedure types.

STUDY DESIGN

Eligible patients in the Mastectomy Reconstruction Outcomes Consortium study from 11 institutions (57 providers) in North America were analyzed. Two-year complications and patient-reported outcomes via BREAST-Q domains were compared across younger (younger than 45 years), middle-aged (45 to 60 years), and older (older than 60 years) women. Mixed-effects regression models were used, controlling for a range of demographic and clinical covariates.

RESULTS

A total of 1,531 patients were studied: 494 younger, 803 middle-aged, and 234 older. Age was not a significant predictor of complications. For sexual well-being 2 years post-reconstruction, older women reported 4.25 (p = 0.04) higher mean scores with implant procedures, and 10.39 (p < 0.01) higher mean scores with autologous procedures compared with younger women. No age effect was seen with implant procedures with regard to physical and psychosocial well-being; however, older women who underwent autologous procedures reported 6.07 (p < 0.01) higher physical, and 8.21 (p < 0.01) higher psychosocial well-being scores than younger women.

CONCLUSIONS

Age did not significantly affect complication rates. Older women demonstrated higher sexual well-being for both procedures, and better satisfaction and physical and psychosocial well-being than younger women with autologous procedures. Post-mastectomy reconstruction is a viable option for older patients, with risks and benefits comparable with those in younger women.

Initiation of and adherence to tamoxifen and aromatase inhibitor therapy among elderly women with ductal carcinoma in situ

BACKGROUND

The National Surgical Adjuvant Breast and Bowel Project B35 and International Breast Cancer Intervention Studies II Ductal Carcinoma In Situ trials showed similar treatment effects of anastrozole and tamoxifen in reducing cancer recurrence risk among ductal carcinoma in situ (DCIS) patients. Studies have shown low levels of hormone therapy drug initiation for DCIS patients, but the current body of literature lacks information on the 5-year adherence rates for these drugs from population-based studies.

METHODS

This study evaluated the initiation and 5-year adherence levels for women aged 66 to 85 years who had been diagnosed with estrogen receptor (ER)-positive DCIS between 2007 and 2011 according to the Surveillance, Epidemiology, and End Results and Texas Cancer Registry databases linked to Medicare claims. Chi-square tests, trend tests, and logistic regression were used to identify factors associated with treatment initiation.

RESULTS

There were 2871 women with ER-positive DCIS, and approximately 45% began treatment with tamoxifen or aromatase inhibitors (AIs) within 1 year of their DCIS diagnosis. The median age was 73 years for the users and 75 years for the nonusers. Women aged 66 to 70 years who underwent lumpectomy and radiation therapy were significantly more likely to initiate hormone therapy. The initiation of therapy was also significantly associated with patients' geographic location, education, marital status, diagnosis year, and race/ethnicity. Among users, adherence decreased from 67% in the first year to 30% in the fifth year.

CONCLUSIONS

Initiation and adherence levels for tamoxifen or AIs among older women with ER-positive DCIS are low. Future studies should develop methods to ensure that informed discussions take place between health care providers and patients regarding hormonal therapy for cancer prevention. Cancer 2017;123:940-47. © 2016 American Cancer Society.

Tamoxifen Initiation After Ductal Carcinoma In Situ

BACKGROUND

Endocrine therapy initiation after ductal carcinoma in situ (DCIS) is highly variable and largely unexplained. National guidelines recommend considering tamoxifen for women with estrogen receptor-positive (ER+) DCIS or who undergo excision alone. We evaluated endocrine therapy use after DCIS over a 15-year period in an integrated health care setting to identify factors related to initiation.

METHODS

Female Group Health Cooperative enrollees ages 18-89 years with a DCIS diagnosis during 1996-2011 were eligible for inclusion. Endocrine therapy was identified through pharmacy records. Tumor and treatment information were from tumor registry reports; demographics and other risk factors were from questionnaires and electronic medical records. Relative risks (RRs) and 95% confidence intervals (CIs) for endocrine therapy initiation were calculated using multivariable generalized linear models.

RESULTS

We identified 727 women with a DCIS diagnosis, including 163 (22%) who initiated endocrine therapy (149 tamoxifen, 14 aromatase inhibitor). Younger women were more likely to initiate endocrine therapy (RR 1.69; 95% CI 1.16-2.46 for ages 45-54 vs. 65-74 years). Compared with breast-conserving surgery (BCS) with radiation, women who had BCS alone (RR 0.46; 95% CI 0.25-0.84) or mastectomy (RR 0.54; 95% CI 0.39-0.75) were less likely to use endocrine therapy. ER testing increased from 4% of DCIS cases in 2001 to 71% in 2011; however, endocrine therapy initiation decreased from 58% of ER+ DCIS in 2001-2005 to 37% in 2009-2011.

CONCLUSION

Increasing ER testing since 2001 has not corresponded to parallel increases in endocrine therapy initiation. Age, surgery, and radiation were the primary factors associated with initiation.

IMPLICATIONS FOR PRACTICE

National guidelines recommend considering tamoxifen for women with ductal carcinoma in situ (DCIS) who are estrogen receptor-positive (ER+) or who undergo excision alone. In this study, the rapid increase in ER testing caused by tamoxifen's approval in 2000 did not lead to increases in endocrine therapy initiation, despite recognition of an increasing number of DCIS tumors as ER+ each year. Contrary to the suggested guidelines, women who had breast-conserving surgery without radiation were less likely to use tamoxifen than those who had radiation. Future Food and Drug Administration approval of new endocrine agents for DCIS (such as aromatase inhibitors) may provide an opportunity to reemphasize benefits by ER and surgery status.

Trends in Treatment Patterns and Outcomes for Ductal Carcinoma In Situ

BACKGROUND

Impact of contemporary treatment of pre-invasive breast cancer (ductal carcinoma in situ [DCIS]) on long-term outcomes remains poorly defined. We aimed to evaluate national treatment trends for DCIS and to determine their impact on disease-specific (DSS) and overall survival (OS).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) registry was queried for patients diagnosed with DCIS from 1991 to 2010. Treatment pattern trends were analyzed using Cochran-Armitage trend test. Survival analyses were performed using inverse probability weights (IPW)-adjusted competing risk analyses for DSS and Cox proportional hazard regression for OS. All tests performed were two-sided.

RESULTS

One hundred twenty-one thousand and eighty DCIS patients were identified. The greatest proportion of patients was treated with lumpectomy and radiation therapy (43.0%), followed by lumpectomy alone (26.5%) and unilateral (23.8%) or bilateral mastectomy (4.5%) with significant shifts over time. The rate of sentinel lymph node biopsy increased from 9.7% to 67.1% for mastectomy and from 1.4% to 17.8% for lumpectomy. Compared with mastectomy, OS was higher for lumpectomy with radiation (hazard ratio [HR] = 0.79, 95% confidence interval [CI] = 0.76 to 0.83, P < .001) and lower for lumpectomy alone (HR = 1.17, 95% CI = 1.13 to 1.23, P < .001). IPW-adjusted ten-year DSS was highest in lumpectomy with XRT (98.9%), followed by mastectomy (98.5%), and lumpectomy alone (98.4%).

CONCLUSIONS

We identified substantial shifts in treatment patterns for DCIS from 1991 to 2010. When outcomes between locoregional treatment options were compared, we observed greater differences in OS than DSS, likely reflecting both a prevailing patient selection bias as well as clinically negligible differences in breast cancer outcomes between groups.

Adjuvant Endocrine Therapy in Patients with Ductal Carcinoma In Situ: A Population-Based Retrospective Analysis from 2005 to 2012 in the National Cancer Data Base

BACKGROUND

Adjuvant endocrine therapy (AET) has been shown to reduce the risk of second breast cancer events in women with ductal carcinoma in situ (DCIS). There is no population-level evaluation of AET use in DCIS patients after standardized reporting of estrogen receptor (ER) status in cancer registries in 2004.

METHODS

We conducted a retrospective cohort study of women with DCIS in the National Cancer Data Base between 2005 and 2012. Patient, tumor, and treatment characteristics as well as temporal trends associated with receipt of AET were evaluated by generalized linear regression.

RESULTS

Among 206,255 DCIS patients, 36.5% received AET. Fewer than half of ER-positive patients (n = 62,146, 46.4%) received AET, with a modest but significant increase over time (43.6% in 2005 to 47.5% in 2012; unadjusted p trend <0.001). AET decreased among ER-negative patients (8.9-6.5%, p trend <0.001) over the same time period. On multivariate analysis, younger (<40 years) and older (≥70 years) women were less likely to receive AET than 50- to 59-year-old women (<40 years: relative risk 0.86, 95% confidence interval 0.82-0.89; ≥70 years: relative risk 0.79, 95% confidence interval 0.77-0.81). ER-positive status conferred a 6.15-fold higher likelihood of receiving AET compared to ER-negative status (95% confidence interval 5.81-6.50). Women who underwent breast-conserving surgery (BCS) with adjuvant radiotherapy were most likely to receive AET.

CONCLUSIONS

Receipt of AET is relatively low in the group of women most likely to benefit from its use, namely ER-positive patients who underwent BCS. Significant variation exists with respect to patient, tumor, site, and treatment factors. More tolerable drugs or clearer guideline recommendations may increase use.

Trends in Treatment Patterns and Outcomes for Ductal Carcinoma In Situ

BACKGROUND

Impact of contemporary treatment of pre-invasive breast cancer (ductal carcinoma in situ [DCIS]) on long-term outcomes remains poorly defined. We aimed to evaluate national treatment trends for DCIS and to determine their impact on disease-specific (DSS) and overall survival (OS).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) registry was queried for patients diagnosed with DCIS from 1991 to 2010. Treatment pattern trends were analyzed using Cochran-Armitage trend test. Survival analyses were performed using inverse probability weights (IPW)-adjusted competing risk analyses for DSS and Cox proportional hazard regression for OS. All tests performed were two-sided.

RESULTS

One hundred twenty-one thousand and eighty DCIS patients were identified. The greatest proportion of patients was treated with lumpectomy and radiation therapy (43.0%), followed by lumpectomy alone (26.5%) and unilateral (23.8%) or bilateral mastectomy (4.5%) with significant shifts over time. The rate of sentinel lymph node biopsy increased from 9.7% to 67.1% for mastectomy and from 1.4% to 17.8% for lumpectomy. Compared with mastectomy, OS was higher for lumpectomy with radiation (hazard ratio [HR] = 0.79, 95% confidence interval [CI] = 0.76 to 0.83, P < .001) and lower for lumpectomy alone (HR = 1.17, 95% CI = 1.13 to 1.23, P < .001). IPW-adjusted ten-year DSS was highest in lumpectomy with XRT (98.9%), followed by mastectomy (98.5%), and lumpectomy alone (98.4%).

CONCLUSIONS

We identified substantial shifts in treatment patterns for DCIS from 1991 to 2010. When outcomes between locoregional treatment options were compared, we observed greater differences in OS than DSS, likely reflecting both a prevailing patient selection bias as well as clinically negligible differences in breast cancer outcomes between groups.