Association of a Diagnosis of Ductal Carcinoma In Situ With Death From Breast Cancer

IMPORTANCE

It is not clear to what extent a diagnosis of ductal carcinoma in situ (DCIS) impacts a woman's lifetime risk of dying of breast cancer. Under ideal circumstances, treatment will eliminate the risk of invasive ipsilateral recurrence and prevent subsequent mortality from breast cancer. The risk of dying of breast cancer after a diagnosis of DCIS had not been compared with that of women without cancer in the general population.

OBJECTIVE

To determine the risk of death from breast cancer in a large cohort of patients treated for DCIS and to compare the risk with that of women in the general population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included data for women who had first primary DCIS diagnosed between 1995 and 2014 from the Surveillance, Epidemiology and End Results (SEER) registries database. Women with DCIS underwent surgical treatment, and approximately half also received radiotherapy. These women were followed from the date of DCIS diagnosis until death from breast cancer or date of last follow-up. Women in the general population without breast cancer were analyzed as controls. Follow-up information was available up to December 2016. The data were analyzed in March 2020.

EXPOSURES

Patients with DCIS who underwent surgical treatment.

MAIN OUTCOMES AND MEASURES

Breast cancer death was the main outcome. Standardized mortality ratios were estimated by comparing deaths from breast cancer among women diagnosed with DCIS with expected deaths from breast cancer among women in the general population who did not have cancer. Expected probability of death from breast cancer in the general population was calculated by an incidence-based mortality approach using standardized SEER-based incidence and case-fatality rates. Probability of breast cancer death was estimated based on the assumption that a cancer-free control was cancer free on the date the woman with DCIS was diagnosed and was studied until the end of follow-up.

RESULTS

A total of 144 524 women diagnosed with first primary DCIS were included (mean [SD] age at diagnosis, 57.4 [11.0] years). There were 1540 deaths from breast cancer in the cohort. Based on SEER-based incidence and case-fatality rates, 458 breast cancer deaths were expected in an equivalent number of cancer-free women from the general population with equal follow-up. The standardized mortality ratio for death from breast cancer among women with DCIS was 3.36 (95% CI, 3.20-3.53). The elevated risk of death persisted more than 15 years after diagnosis.

CONCLUSIONS AND RELEVANCE

In the population studied, the risk of dying of breast cancer was increased 3-fold after a diagnosis of DCIS. This suggests that our current treatment focus on preventing invasive recurrence is insufficient to eliminate all deaths from breast cancer after DCIS.

Evaluation of a Common Prescribing Cascade of Calcium Channel Blockers and Diuretics in Older Adults With Hypertension

IMPORTANCE

Calcium channel blockers (CCBs) are commonly prescribed agents for hypertension that can cause peripheral edema. A prescribing cascade occurs when the edema is misinterpreted as a new medical condition and a diuretic is subsequently prescribed to treat the edema. The extent to which this prescribing cascade occurs at a population level is not well understood.

OBJECTIVE

To measure the association between being newly dispensed a CCB and subsequent dispensing of a loop diuretic in older adults with hypertension.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study was performed using linked health administrative databases of community-dwelling adults 66 years or older with hypertension and new prescription drug claims from September 30, 2011, to September 30, 2016, in Ontario, Canada. The dates of analysis were September 1, 2018, to May 30, 2019.

EXPOSURES

Individuals who were newly dispensed a CCB were compared with the following 2 groups: (1) individuals who were newly dispensed an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker and (2) individuals who were newly dispensed an unrelated medication.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) with 95% CIs were estimated for individuals who were dispensed a loop diuretic within 90 days of follow-up using Cox proportional hazards regression models.

RESULTS

The cohort included 41 086 older adults (≥66 years) with hypertension who were newly dispensed a CCB, 66 494 individuals who were newly dispensed another antihypertensive medication, and 231 439 individuals who were newly dispensed an unrelated medication. At index (ie, the dispensing date), the mean (SD) age was 74.5 (6.9) years, and 191 685 (56.5%) were women. Individuals who were newly dispensed a CCB had a higher cumulative incidence at 90 days of being dispensed a loop diuretic than individuals in both control groups (1.4% vs 0.7% and 0.5%, P < .001). After adjustment, individuals who were newly dispensed a CCB had increased relative rates of being dispensed a loop diuretic compared with individuals who were newly dispensed an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (HR, 1.68; 95% CI, 1.38-2.05 in the first 30 days after index [days 1-30]; 2.26; 95% CI, 1.76-2.92 in the subsequent 30 days [days 31-60]; and 2.40; 95% CI, 1.84-3.13 in the third month of follow-up [days 61-90]) and individuals who were newly dispensed unrelated medications (HR, 2.51; 95% CI, 2.13-2.96 for 1-30 days after index; 2.99; 95% CI, 2.43-3.69 for 31-60 days after index; and 3.89; 95% CI, 3.11-4.87 for 61-90 days after index). This association persisted, although slightly attenuated, from 90 days to up to 1 year of follow-up and when restricted to a subgroup of individuals who were newly dispensed amlodipine.

CONCLUSIONS AND RELEVANCE

Many older adults with hypertension who are newly dispensed a CCB subsequently receive a loop diuretic. Given how widely CCBs are prescribed, interventions are needed to raise clinicians' awareness of this common prescribing cascade to reduce the prescribing of potentially unnecessary medications that may cause harm.

Impact of diabetes on colorectal cancer stage and mortality risk: a population-based cohort study

AIMS/HYPOTHESIS

Diabetes is associated with an increased incidence of colorectal cancer (CRC). There exists conflicting evidence regarding the impact of diabetes on CRC-specific mortality (herein also referred to as cancer-specific mortality). The objectives of this study were to determine whether diabetes is associated with a more advanced CRC stage at diagnosis and with higher all-cause and cancer-specific mortality.

METHODS

This retrospective cohort study used linked, population-based health databases from Ontario, Canada. Among individuals diagnosed with CRC from 2007 to 2015, we compared the likelihood of presenting with later- (III or IV) vs early- (I or II) stage CRC between patients with and without diabetes adjusting for relevant covariates. We then determined the association between diabetes and all-cause and CRC-specific mortality, after adjusting for CRC stage at diagnosis and other covariates.

RESULTS

Of the 44,178 individuals with CRC, 11,822 (26.7%) had diabetes. After adjustment for CRC screening and other covariates, individuals with diabetes were not more likely to present with later-stage CRC (adjusted OR 0.97, 95% CI 0.93, 1.01). Over a median follow-up of 2.63 (interquartile range [IQR] 0.97-5.10) years, diabetes was associated with higher all-cause mortality (adjusted HR 1.08, 95% CI 1.04, 1.12) but similar cancer-specific survival (adjusted HR 1.0, 95% CI 0.95, 1.06).

CONCLUSIONS/INTERPRETATION

Individuals with diabetes who develop CRC are not more likely to present with a later stage of CRC and have similar cancer-specific mortality compared with those without diabetes. Diabetes was associated with higher all-cause mortality in CRC patients, indicating that greater attention to non-cancer care is needed for CRC survivors with diabetes.

Effectiveness of confidential reports to physicians on their prescribing of antipsychotic medications in nursing homes

Background

Antipsychotic medication use in nursing homes is associated with potential for harms. In Ontario, Canada, an agency of the provincial government offers nursing home physicians quarterly audit and feedback on their antipsychotic prescribing. We compared the characteristics of physicians who did and did not engage with the intervention, and assessed early changes in prescribing.

Methods

This population-level, retrospective cohort study used linked administrative databases to track prescribing practices in nursing homes pre-intervention (baseline), immediately post-initiative (3 months), and at follow-up (6 months). Exposure variables identified whether a physician signed up to participate (or not) or viewed the feedback following sign up (or not). Differences in the proportion of days that residents received antipsychotic medications at 6 months compared to baseline by exposure(s) were assessed using a linear mixed effects regression analysis to adjust for a range of resident, physician, and nursing home factors. Benzodiazepine and statin prescribing were assessed as a balance and tracer measures, respectively.

Results

Of 944 eligible physicians, 210 (22.3%) signed up to recieve the feedback report and 132 (13.9%) viewed their feedback. Physicians who signed up for feedback were more likely to have graduated from a Canadian medical school, work in urban nursing homes, and care for a larger number of residents. The clinical and functional characteristics of residents were similar across physician exposure groups. At 6 months, antipsychotic prescribing had decreased in all exposure groups. Those who viewed their feedback report had a signicantly greater reduction in antipsychotic prescribing than those who did not sign up (0.94% patient-days exposed; 95% CI 0.35 to 1.54%, p = 0.002). Trends in prescribing patterns across exposure groups for benzodiazepines and statins were not statistically significant.

Interpretation

Almost a quarter of eligible physicians engaged early in a voluntary audit and feedback intervention related to antipsychotic prescribing in nursing homes. Those who viewed their feedback achieved a small but statistically significant change in prescribing, equivalent to approximately 14,000 fewer days that nursing home residents received antipsychotic medications over 6 months. This study adds to the literature regarding the role of audit and feedback interventions to improve quality of care.

Abstract P5-07-07: A generalizable relationship between mortality and time-to-death among breast cancer patients can be explained by tumor dormancy

Background: Women with ER-positive breast cancer may recur as late as twenty years post diagnosis. The reason for this delayed recurrence is unknown. We studied survival patterns, including time-to-death in 123,705 women with stage I to III invasive breast cancer, enrolled in the SEER database. We sought to determine if time from diagnosis to death could be explained by variation in tumor dormancy.

Methods: We divided the cohort into ten classes based on their 20-year risks of death from breast cancer. Probability of death at 20 years was estimated for each patient using year of diagnosis, patient characteristics (age, race, household income), tumor characteristics (grade, tumor size, nodal status, stage, ER and PR-status) and treatment (radiotherapy, chemotherapy). The 20-year mortality for women in the highest risk decile (decile 10) was 69% versus 5% for women in the lowest decile (decile 1). We define a variable α which represents the annual rate of reactivation from tumor dormancy. Using the highest risk decile as a reference distribution, we determined what α value gives the best fit for the time-to-death distribution of each decile. As a complementary analysis we performed quantile regression to determine independent predictors of time-to-death among women who died from breast cancer.

Results: The duration of tumor dormancy was much longer, on average, for ER-positive breast cancers than for ER-negative breast cancers. Time at peak mortality rate monotonically decreased by decile, ranging from 19 years post-diagnosis in the lowest risk decile to two years post-diagnosis in the highest risk decile (Table 1). The difference in the time-to-death distributions by decile could be explained by the variable α which represents the annual rate of reactivation from tumor dormancy.

In the regression analysis, ER-positive breast cancers had a median time-to-death 3.67 years longer than ER-negative breast cancers (Table 2). However, this effect was attenuated by risk factors correlated with ER status (adjusted difference 1.76 years). Notable independent predictors of time-to-death include ethnicity, tumor size, grade, nodal status and PR-status.

Conclusion: Reactivation from tumor dormancy appears to occur at random wherein the rate of tumor activation is correlated with probability of death from breast cancer. This model may explain the very long time to cancer recurrence in women with ER-positive node-negative breast cancers. The clinical course of women with low-risk breast cancer is inherently unpredictable.

Table 1: Factors related to breast cancer mortality and time-to-death by decile.Risk DecileNumber of patients (N)Annual death rate (per 100 person-years)20-year actuarial mortality (%)Peak mortality time (years)Median time-to-death (years)10th percentile time-to-death (years)90th percentile time-to-death (years)Optimal α (reactivations per person-year)112,3700.255.3%19.012.24.018.70.10212,3710.438.6%19.511.04.318.40.16312,3700.6011.3%9.510.33.517.60.20412,3710.7413.2%5.58.93.016.70.32512,3700.9016.0%3.58.62.617.40.32612,3711.1720.0%4.08.12.616.90.35712,3711.5124.8%3.07.62.316.70.41812,3702.1231.7%3.06.41.915.90.74912,3713.2242.5%2.55.61.714.81.291012,3706.6463.0%2.03.81.112.3InF (Ref.)

Table 2: Predictors of time-to-death in breast cancer patients.PredictorValueUnadjustedAdjustedMedian time-to-death (years)Difference* (years)Difference (years)**POverall/ Reference5.6713.05***&lt;.0001Year of diagnosis19905.42Reference19915.670.250.170.360919925.670.250.220.289919935.580.170.350.059919946.000.580.530.0054Age at diagnosis&lt;505.58Reference50-595.920.330.070.580760-696.170.58-0.060.655170-805.25-0.33-1.18&lt;.0001EthnicityWhite5.75ReferenceBlack4.33-1.42-0.320.009East Asian6.670.920.930.0058Southeast Asian6.080.330.090.8208Other/Unknown6.170.420.420.4176Tumor size (cm)&lt;1cm8.33Reference1-2cm7.33-1.00-0.650.07922-3cm5.58-2.75-1.42&lt;.00013-5cm4.75-3.58-1.76&lt;.00015+cm3.83-4.50-2.16&lt;.0001Tumor gradeI11.17ReferenceII7.58-3.58-2.82&lt;.0001III4.25-6.92-4.78&lt;.0001IV3.92-7.25-5.18&lt;.0001Unknown6.25-4.92-3.57&lt;.0001Nodal statusN06.83ReferenceN15.67-1.17-0.69&lt;.0001N25.00-1.83-1.08&lt;.0001N33.83-3.00-2.03&lt;.0001Unknown2.42-4.42-2.32&lt;.0001ER statusPositive7.17ReferenceNegative3.50-3.67-1.76&lt;.0001PR statusPositive7.25ReferenceNegative3.83-3.42-1.7&lt;.0001Unknown5.08-2.17-1.35&lt;.0001RadiotherapyNo5.42ReferenceYes6.080.670.260.0214Unknown5.08-0.33-0.470.1043ChemotherapyNo/Unknown6.58ReferenceYes5.17-1.42-0.310.0091*Difference in median time-to-death relative to reference value.**Independent difference in median time-to-death after adjusting for all covariates in table.***Median time-to-death of the reference group.

Citation Format: Vasily Giannakeas, Steven A Narod. A generalizable relationship between mortality and time-to-death among breast cancer patients can be explained by tumor dormancy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-07-07.

Sex Differences in the Prevalent Use of Oral Formulations of Cholinesterase Inhibitors in Older Adults with Dementia

BACKGROUND

Cholinesterase inhibitors (ChEIs) are one of only two drug therapies available to manage cognitive decline in dementia. Given sex-specific differences in medication access and effects, it is important to understand how ChEIs are used by women and men.

OBJECTIVE

The objective of this study was to provide contemporary sex-stratified evidence on patterns of ChEI use by community-dwelling older adults with dementia to inform opportunities to optimize drug prescribing.

METHODS

We conducted a population-based cross-sectional study examining ChEI use in older adults with dementia in Ontario, Canada. We identified all community-dwelling individuals aged 66 years and older with a pre-existing diagnosis of dementia as of 1 April, 2016. We examined the prevalence of ChEI use among women and men separately, and explored the association between ChEI use and age, sex, income status, geographic location of residence, use of palliative care services, comorbidity, and polypharmacy. Concurrent use of drugs known to impair cognition (including antipsychotics, benzodiazepines, and medications with strong anticholinergic properties) was separately assessed among women and men using multivariable analyses and prevalence risk ratios.

RESULTS

Of 74,799 women and 52,231 men living with dementia in the community, nearly 30% currently were using a ChEI (29.3% women, 28.6% men). Close to 70% of users were receiving the target therapeutic dose. Compared to men, women were less often taking the target therapeutic dose (67.8% women vs. 71.6% men, p < 0.001). Over 20% of users also were using drugs known to impair cognition, while being treated for cognitive decline using ChEIs. Compared to men, women were more often concurrently using drugs known to impair cognition (23.9% women vs. 21.8% men, p < 0.001).

CONCLUSIONS

This is one of the first studies of ChEI use to account for important sex differences. The results remind clinicians and researchers that patterns of ChEI therapy use differ by sex, as women were less likely to receive target therapeutic doses and more vulnerable to potentially problematic polypharmacy than men.

Sex-Specific Differences in End-of-Life Burdensome Interventions and Antibiotic Therapy in Nursing Home Residents With Advanced Dementia

IMPORTANCE

Nursing home residents with advanced dementia have limited life expectancies yet are commonly subjected to burdensome interventions at the very end of life. Whether sex-specific differences in the receipt of these interventions exist and what levels of physical restraints and antibiotics are used in this terminal setting are unknown.

OBJECTIVE

To evaluate the population-based frequency, factors, and sex differences in burdensome interventions and antibiotic therapy among nursing home residents with advanced dementia.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study from Ontario, Canada, used linked administrative databases held at ICES, including the Continuing Care Resident Reporting System Long-Term Care database, which contains data from the Resident Assessment Instrument Minimum Data Set, version 2.0. Nursing home residents (n = 27 243) with advanced dementia who died between June 1, 2010, and March 31, 2015, at 66 years or older were included in the analysis. Initial statistical analysis was completed in May 2017, and analytical revisions were conducted from November 2018 to January 2019.

EXPOSURE

Sex of the nursing home resident.

MAIN OUTCOMES AND MEASURES

Burdensome interventions (transitions of care, invasive procedures, and physical restraints) and antibiotic therapy in the last 30 days of life.

RESULTS

The final cohort included 27 243 nursing home residents with advanced dementia (19 363 [71.1%] women) who died between June 1, 2010, and March 31, 2015, at the median (interquartile range) age of 88 (83-92) years. In the last 30 days of life, burdensome interventions were common, especially among men: 5940 (21.8%) residents were hospitalized (3661 women [18.9%] vs 2279 men [28.9%]; P < .001), 2433 (8.9%) had an emergency department visit (1579 women [8.2%] vs 854 men [10.8%]; P < .001), and 3701 (13.6%) died in an acute care facility (2276 women [11.8%] vs 1425 men [18.1%]; P < .001). Invasive procedures were also common; 2673 residents (9.8%) were attended for life-threatening critical care (1672 women [8.6%] vs 1001 men [12.7%]; P < .001), and 210 (0.8%) received mechanical ventilation (113 women [0.6%] vs 97 men [1.2%]; P < .001). Among the 9844 residents (36.1%) who had a Resident Assessment Instrument Minimum Data Set, version 2.0, completed in the last 30 days of life, 2842 (28.9%) were physically restrained (2002 women [28.3%] vs 840 men [30.4%]; P = .005). More than one-third (9873 [36.2%]) of all residents received an antibiotic (6599 women [34.1%] vs 3264 men [41.4%]; P < .001). In multivariable models, men were more likely to have a transition of care (adjusted odds ratio, 1.41; 95% CI, 1.33-1.49; P < .001) and receive antibiotics (adjusted odds ratio, 1.33; 95% CI, 1.26-1.41; P < .001). Only 3309 residents (12.1%; 2382 women [12.3%] vs 927 men [11.8%]) saw a palliative care physician in the year before death, but those who did experienced greater than 50% lower odds of an end-of-life transition of care (adjusted odds ratio, 0.48; 95% CI, 0.43-0.54); P < .001) and greater than 25% lower odds of receiving antibiotics (adjusted odds ratio, 0.74; 95% CI, 0.68-0.81; P < .001).

CONCLUSIONS AND RELEVANCE

In this study, many nursing home residents with advanced dementia, especially men, received burdensome interventions and antibiotics in their final days of life. These findings appear to emphasize the need for sex-specific analysis in dementia research as well as the expansion of palliative care and end-of-life antimicrobial stewardship in nursing homes.

A generalizable relationship between mortality and time-to-death among breast cancer patients can be explained by tumour dormancy

Background

Women with ER-positive breast cancer may recur as late as 20 years post-diagnosis. The reason for this delayed recurrence is unknown. We studied survival patterns, including time-to-death in 123,705 women with stage I to III invasive breast cancer, enrolled in the SEER database. Among these 76.8% were ER-positive and 23.2% were ER-negative.

Methods

We divided the cohort into ten classes with varying risks of death from breast cancer. The 20-year mortality for women in the highest risk decile 10 was 69% versus 5% for women in the lowest decile 1. The difference in the time-to-death by decile could be explained by a variable α which represents the annual rate of reactivation from tumour dormancy.

Results

The duration of tumour dormancy was much longer, on average, for ER-positive breast cancers than for ER-negative breast cancers. Reactivation from tumour dormancy appears to occur at random and may explain the very long time to cancer recurrence in women with small node-negative ER-positive breast cancers.

Conclusion

The clinical course of women with low-risk ER-positive breast cancer is inherently unpredictable and consequently death is equally as likely to occur at year 3 than at year 20.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05334-5) contains supplementary material, which is available to authorized users.

The Association Between Insulin Initiation and Adverse Outcomes After Hospital Discharge in Older Adults: a Population-Based Cohort Study

BACKGROUND

Starting insulin therapy in hospitalized patients may be associated with an increase in serious adverse events after discharge.

OBJECTIVE

Determine whether post-discharge risks of death and rehospitalization are higher for older hospitalized patients prescribed new insulin therapy compared with oral hypoglycemic agents (OHAs).

DESIGN

Retrospective population-based cohort study including hospital admissions in Ontario, Canada, between April 1, 2004, and Nov 30, 2013.

PATIENTS

Persons aged 66 and over discharged after a hospitalization and dispensed a prescription for insulin and/or an OHA within 7 days of discharge. We included 104,525 individuals, subcategorized into four mutually exclusive exposure groups based on anti-hyperglycemic drug use in the 7 days post-discharge and the 365 days prior to the index admission.

MAIN MEASURES

Prescriptions at discharge were categorized as new insulin (no insulin before admission), prevalent insulin (prescribed insulin before admission), new OHA(s) (no OHA or insulin before admission), and prevalent OHA (prescribed OHA only before admission) as the referent category. The primary and secondary outcomes were 30-day deaths and emergency department (ED) visits or readmissions respectively.

KEY RESULTS

Of 104,525 patients, 9.2% were initiated on insulin, 4.1% died, and 26.2% had an ED visit or readmission within 30 days of discharge. Deaths occurred in 7.14% of new insulin users, 4.86% of prevalent insulin users, 3.25% of new OHA users, and 3.45% of prevalent OHA users. After adjustment for covariates, new insulin users had a significantly higher risk of death (adjusted hazard ratio (aHR) 1.59, 95% confidence interval (CI) 1.46 to 1.74) and ED visit/readmissions (aHR 1.17, 95% CI 1.12 to 1.22) than prevalent OHA users.

CONCLUSIONS

Initiation of insulin therapy in older hospitalized patients is associated with a higher risk of death and ED visits/readmissions after discharge, highlighting a need for better transitional care of insulin-treated patients.

Denosumab and breast cancer risk in postmenopausal women: a population-based cohort study

BACKGROUND

Denosumab inhibits the receptor activator of nuclear factor κB (RANK) pathway and is used to treat osteoporosis. Emerging evidence suggests RANK-blockade may play a role in mammary tumourigenesis. Thus, we undertook a population-based study of denosumab use and breast cancer risk in a large cohort of postmenopausal women.

METHODS

We included women 67+ years with prior bisphosphonate use who filled a first prescription for denosumab. They were matched on age, date, cumulative prior use of and time since last use of a bisphosphonate to women with no history of denosumab. Cox proportional hazards was used to estimate the hazard ratio (HR) of breast cancer with denosumab use.

RESULTS

A total of 100,368 women were included in the analysis with 1271 incident breast cancer events. Denosumab use was associated with a 13% decreased breast cancer risk (HR = 0.87; 95% CI 0.76-1.00). There was no relationship between increasing number of denosumab doses and breast cancer risk (P-trend = 0.15).

CONCLUSION

These findings suggest a potential protective effect of ever denosumab use on breast cancer risk in a cohort of older women previously treated with bisphosphonates.

Time to death in breast cancer patients as an indicator of treatment response

PURPOSE

To describe the mortality experience of women who die of breast cancer in the 20-year period post-diagnosis using various metrics, including annual mortality rates, Kaplan-Meier survival curves and time-to-death histograms.

METHODS

We generated three visual representations of SEER-based and hospital-based breast cancer patient cohorts using three different metrics of mortality.

RESULTS

The greatest impact of most prognostic factors was on the probability of latent metastases present after treatment, but for some factors the primary impact was on the time to death for those women with metastases.

CONCLUSIONS

The use of time-to-death statistics to display mortality benefits for treated versus untreated women helps facilitate the distinction between treatments which increase the likelihood of cure and treatments that delay cancer growth.

Association of Radiotherapy With Survival in Women Treated for Ductal Carcinoma In Situ With Lumpectomy or Mastectomy

IMPORTANCE

Patients with ductal carcinoma in situ (DCIS) are treated with radiotherapy to reduce their risk of local invasive recurrence after breast-conserving surgery. However, the association of radiotherapy with breast cancer survival in patients with DCIS has not yet been clearly established.

OBJECTIVE

To determine the extent to which radiotherapy is associated with reduced risk of breast cancer mortality in a large cohort of patients treated for DCIS, using a propensity score-based matching approach.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of women who had first primary DCIS diagnosed between 1998 and 2014 used data from the Surveillance, Epidemiology, and End Results 18 registries database. Information on age and year of diagnosis, ethnicity, income, tumor size, tumor grade, estrogen receptor status, all treatments (surgery and radiation), and outcomes (invasive local recurrence and death from breast cancer) was abstracted for 140 366 women diagnosed with first primary DCIS. Three separate comparisons were performed using 1:1 matching: lumpectomy with radiation vs lumpectomy alone; lumpectomy alone vs mastectomy; and lumpectomy with radiation vs mastectomy.

EXPOSURES

Use of radiotherapy and/or extent of surgery.

MAIN OUTCOMES AND MEASURES

Crude and adjusted 15-year breast cancer-specific mortality.

RESULTS

Of the 140 366 patients with DCIS in the cohort (109 712 [78.2%] white; mean [SD] age, 58.8 [12.3] years), 35 070 (25.0%) were treated with lumpectomy alone, 65 301 (46.5%) were treated with lumpectomy and radiotherapy, and 39 995 (28.5%) were treated with mastectomy. The actuarial 15-year breast cancer mortality rate was 2.33% for patients treated with lumpectomy alone, 1.74% for patients treated with lumpectomy and radiation, and 2.26% for patients treated with mastectomy. The adjusted hazard ratios for death were 0.77 (95% CI, 0.67-0.88) for lumpectomy and radiotherapy vs lumpectomy alone (29 465 propensity-matched pairs), 0.91 (95% CI, 0.78-1.05) for mastectomy alone vs lumpectomy alone (20 832 propensity-matched pairs), and 0.75 (95% CI, 0.65-0.87) for lumpectomy and radiotherapy vs mastectomy (29 865 propensity-matched pairs).

CONCLUSIONS AND RELEVANCE

In patients with DCIS, treatment with lumpectomy and radiotherapy was associated with a significant reduction in breast cancer mortality compared with either lumpectomy alone or mastectomy alone. This suggests that the survival benefit of radiation is likely not due to local control, but rather to systemic effects.

Public reporting of antipsychotic prescribing in nursing homes: population-based interrupted time series analyses

Background

Although sometimes appropriate, antipsychotic medications are associated with increased risk of significant adverse events. In 2014, a series of newspaper articles describing high prescribing rates in nursing homes in Ontario, Canada, garnered substantial interest. Subsequently, an online public reporting initiative with home-level data was launched. We examined the impact of these public reporting interventions on antipsychotic prescribing in nursing homes.

Methods

Time series analysis of all nursing home residents in Ontario, Canada, between 1 October 2013 and 31 March 2016. The primary outcome was the proportion of residents prescribed antipsychotics each month. Balance measures were prescriptions for common alternative sedating agents (benzodiazepines and/or trazodone). We used segmented regression to assess the effects on prescription trends of the newspaper articles and the online home-level public reporting initiative.

Results

We included 120 009 nursing home resident admissions across 636 nursing homes. Following the newspaper articles, the proportion of residents prescribed an antipsychotic decreased by 1.28% (95% CI 1.08% to 1.48%) and continued to decrease at a rate of 0.2% per month (95% CI 0.16% to 0.24%). The online public reporting initiative did not alter this trend. Over 3 years, there was a net absolute reduction in antipsychotic prescribing of 6.0% (95% CI 5.1% to 6.9%). Trends for benzodiazepine prescribing did not change as substantially during the period of observation. Trazodone use has been gradually increasing, but its use did not change abruptly at the time of the mass media report or the public reporting initiative.

Interpretation

The rapid impact of mass media on prescribing suggests both an opportunity to use this approach to invoke change and a warning to ensure that such reporting occurs responsibly.