Factors associated with radiation therapy incompletion for patients with early-stage breast cancer

Treatment Terminations During Radiation Therapy: A 10-Year Experience

PURPOSE

Patients undergoing radiation therapy may terminate treatment for any number of reasons. The incidence of treatment termination (TT) during radiation therapy has not been studied. Herein, we present a cohort of TT at a large multicenter radiation oncology department over 10 years.

METHODS AND MATERIALS

TTs between January 2013 and January 2023 were prospectively analyzed as part of an ongoing departmental quality and safety program. TT was defined as any premature discontinuation of therapy after initiating radiation planning. The rate of TT was calculated as a percentage of all patients starting radiation planning. All cases were presented at monthly morbidity and mortality conferences with a root cause reviewed.

RESULTS

A total of 1448 TTs were identified out of 31,199 planned courses of care (4.6%). Six hundred eighty-six (47.4%) involved patients treated with curative intent, whereas 753 (52.0%) were treated with palliative intent, and 9 (0.6%) were treated for benign disease. The rate of TT decreased from 8.49% in 2013 to 3.02% in 2022, with rates decreasing yearly. The most common disease sites for TT were central nervous system (21.7%), head and neck (19.3%), thorax (17.5%), and bone (14.2%). The most common causes of TT were hospice and/or patient expiration (35.9%), patient choice unrelated to toxicity (35.2%), and clinician choice unrelated to toxicity (11.5%).

CONCLUSIONS

This 10-year prospective review of TTs identified a year-over-year decrease in TTs as a percentage of planned patients. This decrease may be associated with the addition of root cause reviews for TTs and discussions monthly at morbidity and mortality rounds, coupled with departmental upstream quality initiatives implemented over time. Understanding the reasons behind TTs may help decrease preventable TTs. Although some TTs may be unavoidable, open discourse and quality improvement changes effectively reduce TT incidents over time.

Preexisting Diabetes and Breast Cancer Treatment Among Low-Income Women

IMPORTANCE

Diabetes is associated with poorer prognosis of patients with breast cancer. The association between diabetes and adjuvant therapies for breast cancer remains uncertain.

OBJECTIVE

To comprehensively examine the associations of preexisting diabetes with radiotherapy, chemotherapy, and endocrine therapy in low-income women with breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included women younger than 65 years diagnosed with nonmetastatic breast cancer from 2007 through 2015, followed up through 2016, continuously enrolled in Medicaid, and identified from the linked Missouri Cancer Registry and Medicaid claims data set. Data were analyzed from January 2022 to October 2023.

EXPOSURE

Preexisting diabetes.

MAIN OUTCOMES AND MEASURES

Logistic regression was used to estimate odds ratios (ORs) of utilization (yes/no), timely initiation (≤90 days postsurgery), and completion of radiotherapy and chemotherapy, as well as adherence (medication possession ratio ≥80%) and persistence (<90-consecutive day gap) of endocrine therapy in the first year of treatment for women with diabetes compared with women without diabetes. Analyses were adjusted for sociodemographic and tumor factors.

RESULTS

Among 3704 women undergoing definitive surgery, the mean (SD) age was 51.4 (8.6) years, 1038 (28.1%) were non-Hispanic Black, 2598 (70.1%) were non-Hispanic White, 765 (20.7%) had a diabetes history, 2369 (64.0%) received radiotherapy, 2237 (60.4%) had chemotherapy, and 2505 (67.6%) took endocrine therapy. Compared with women without diabetes, women with diabetes were less likely to utilize radiotherapy (OR, 0.67; 95% CI, 0.53-0.86), receive chemotherapy (OR, 0.67; 95% CI, 0.48-0.93), complete chemotherapy (OR, 0.71; 95% CI, 0.50-0.99), and be adherent to endocrine therapy (OR, 0.71; 95% CI, 0.56-0.91). There were no significant associations of diabetes with utilization (OR, 0.95; 95% CI, 0.71-1.28) and persistence (OR, 1.09; 95% CI, 0.88-1.36) of endocrine therapy, timely initiation of radiotherapy (OR, 1.09; 95% CI, 0.86-1.38) and chemotherapy (OR, 1.09; 95% CI, 0.77-1.55), or completion of radiotherapy (OR, 1.25; 95% CI, 0.91-1.71).

CONCLUSIONS AND RELEVANCE

In this cohort study, preexisting diabetes was associated with subpar adjuvant therapies for breast cancer among low-income women. Improving diabetes management during cancer treatment is particularly important for low-income women with breast cancer who may have been disproportionately affected by diabetes and are likely to experience disparities in cancer treatment and outcomes.

Early Cardiac Effects of Contemporary Radiation Therapy in Patients With Breast Cancer

PURPOSE

To characterize the early changes in echocardiographically derived measures of cardiac function with contemporary radiation therapy (RT) in breast cancer and to determine the associations with radiation dose-volume metrics, including mean heart dose (MHD).

METHODS AND MATERIALS

In a prospective longitudinal cohort study of 86 patients with breast cancer treated with photon or proton thoracic RT, clinical and echocardiographic data were assessed at 3 time points: within 4 weeks before RT initiation (T0), within 3 days before 6 weeks after the end of RT (T1), and 5 to 9 months after RT completion (T2). Associations between MHD and echocardiographically derived measures of cardiac function were assessed using generalized estimating equations to define the acute (T0 to T1) and subacute (T0 to T2) changes in cardiac function.

RESULTS

The median estimates of MHD were 139 cGy (interquartile range, 99-249 cGy). In evaluating the acute changes in left ventricular ejection fraction (LVEF) from T0 to T1, and accounting for the time from RT, age, race, preexisting cardiovascular disease, and an interaction term with anthracycline or trastuzumab exposure and MHD, there was a modest decrease in LVEF of borderline significance (0.22%; 95% confidence interval [CI], -0.44% to 0.01%; P = .06) per 30-day interval for every 100 cGy increase of MHD. Similarly, there was a modest worsening in longitudinal strain (0.19%; 95% CI, -0.01% to 0.39%; P = .06) per 30-day interval for each 100 cGy increase in MHD. We did not find significant associations between MHD and changes in circumferential strain or diastolic function.

CONCLUSIONS

With modern radiation planning techniques, there are modest subclinical changes in measures of cardiac function in the short-term. Longer-term follow-up studies are needed to determine whether these early changes are associated with the development of overt cardiac disease.

Factors Associated with Refusal or Discontinuation of Treatment in Patients with Bladder Cancer: A Cohort Population-Based Study in Taiwan

Cancer treatment causes adverse effects that lead to refusal or discontinuation of treatment. The purposes of this study were to identify 1) the factors associated with and 2) the reasons for refusing and discontinuing treatment in patients with bladder cancer (BC). We conducted a retrospective cohort study in patients diagnosed with BC in Taiwan from 1 January 2014 to 30 June 2019 using a linked cancer registry database. Of the 1247 BC patients in the study cohort, 2.1% reported refusing treatment. Patients with less education and those diagnosed at cancer stage II-IV were more likely to refuse treatment. The major reason for refusing treatment was "patient or the family considered patient's poor physical condition (chronic disease or unstable systemic disease), difficulty in enduring any condition likely to cause physical discomfort from disease treatment". A total of 4.3% of BC patients reported discontinuing treatment. Patients not living in the northern region of Taiwan and those diagnosed at cancer stage II-IV were more likely to terminate treatment before completion. The major reason given for discontinuing treatment was inconvenient transportation. Sufficient social resources and supportive care can help BC patients cope with the physical and psychological burden of treatment.

Comorbidity Assessment in the National Cancer Database for Patients With Surgically Resected Breast, Colorectal, or Lung Cancer (AFT-01, -02, -03)

PURPOSE

Accurate comorbidity measurement is critical for cancer research. We evaluated comorbidity assessment in the National Cancer Database (NCDB), which uses a code-based Charlson-Deyo Comorbidity Index (CCI), and compared its prognostic performance with a chart-based CCI and individual comorbidities in a national sample of patients with breast, colorectal, or lung cancer.

PATIENTS AND METHODS

Through an NCDB Special Study, cancer registrars re-abstracted perioperative comorbidities for 11,243 patients with stage II to III breast cancer, 10,880 with stage I to III colorectal cancer, and 9,640 with stage I to III lung cancer treated with definitive surgical resection in 2006-2007. For each cancer type, we compared the prognostic performance of the NCDB code-based CCI (categorical: 0 or missing data, 1, 2+), Special Study chart-based CCI (continuous), and 18 individual comorbidities in three separate Cox proportional hazards models for postoperative 5-year overall survival.

RESULTS

Comorbidity was highest among patients with lung cancer (13.2% NCDB CCI 2+) and lowest among patients with breast cancer (2.8% NCDB CCI 2+). Agreement between the NCDB and Special Study CCI was highest for breast cancer (rank correlation, 0.50) and lowest for lung cancer (rank correlation, 0.40). The NCDB CCI underestimated comorbidity for 19.1%, 29.3%, and 36.2% of patients with breast, colorectal, and lung cancer, respectively. Within each cancer type, the prognostic performance of the NCDB CCI, Special Study CCI, and individual comorbidities to predict postoperative 5-year overall survival was similar.

CONCLUSION

The NCDB underestimated comorbidity in patients with surgically resected breast, colorectal, or lung cancer, partly because the NCDB codes missing data as CCI 0. However, despite underestimation of comorbidity, the NCDB CCI was similar to the more complete measures of comorbidity in the Special Study in predicting overall survival.

Spatial barriers impact upon appropriate delivery of radiotherapy in breast cancer patients

Radiotherapy (RT) is the standard treatment for breast cancer patients after conserving surgery or mastectomy when patients are at high risk of relapse. Major obstacles to appropriate RT delivery are journey times. Since studies on access to RT were carried out mostly in large countries, this study investigated factors in an Italian region and the influence of RT delivery on survival. A total of 4735 female candidates for RT were included in the study. A geographic information system calculated journey times from patients' homes and surgery hospitals to RT centers. Logistic regression analyzed the influence of journey times, socioeconomic status, and other factors on RT delivery. Survival probabilities and excess mortality were assessed in 4364 propensity score-matched patients. Journey times of 40 min or less from residence and from surgery hospital to RT center played a major role in access to RT. A large survival difference emerged between treated and untreated breast cancer patients. The excess mortality for untreated patients compared with propensity score-matched women receiving RT was 3.1 (95% CI: 2.2-4.3). Expansion of RT facilities during the 11-year study period improved RT delivery and outcomes by increasing availability but mainly by shortening journey times.

How do age and molecular subtypes impact surgical decisions?

Tumor molecular subtype and patient age are the predominant drivers of recommendations for systemic therapy in patients with breast cancer. Yet, the impact of these factors on surgical decision-making remains controversial. Younger women often receive the most extensive surgical therapy despite a lack of evidence that bigger surgery translates into better outcomes. In contrast, among older women, there is a desire to minimize local therapy and its associated morbidity. Here, we review contemporary data highlighting the relationship between patient age and breast cancer molecular subtype, and local therapy outcomes. Our perspective is that tumor biology, rather than age, should be the driving factor in determining appropriate local therapy for breast cancer.

Healthcare System Distrust, Physician Trust, and Patient Discordance with Adjuvant Breast Cancer Treatment Recommendations

Background: Adjuvant therapy after breast cancer surgery decreases recurrence and increases survival, yet not all women receive and complete it. Previous research has suggested that distrust in medical institutions plays a role in who initiates adjuvant treatment, but has not assessed treatment completion, nor the potential mediating role of physician distrust.Methods: Women listed in Pennsylvania and Florida cancer registries, who were under the age of 65 when diagnosed with localized invasive breast cancer between 2005 and 2007, were surveyed by mail in 2007 to 2009. Survey participants self-reported demographics, cancer stage and treatments, treatment discordance (as defined by not following their surgeon or oncologist treatment recommendation), healthcare system distrust, and physician trust. Age and cancer stage were verified against cancer registry records. Logistic regression assessed the relationship between highest and lowest tertiles of healthcare system distrust and the dichotomous outcome of treatment discordance, controlling for demographics and clinical treatment factors, and testing for mediation by physician trust.Results: Of the 2,754 participants, 30.2% (n = 832) reported not pursing at least one recommended treatment. The mean age was 52. Patients in the highest tertile of healthcare system distrust were 22% more likely to report treatment discordance than the lowest tertile; physician trust did not mediate the association between healthcare system distrust and treatment discordance.Conclusions: Healthcare system distrust is positively associated with treatment discordance, defined as failure to initiate or complete physician-recommended adjuvant treatment after breast cancer.Impact: Interventions should test whether or not resolving institutional distrust reduces treatment discordance. Cancer Epidemiol Biomarkers Prev; 26(12); 1745-52. ©2017 AACR.

Trends in adjuvant therapies after breast-conserving surgery for hormone receptor-positive ductal carcinoma in situ: findings from the National Cancer Database, 2004-2013

PURPOSE

Breast-conserving surgery (BCS) followed by radiotherapy (RT) with or without endocrine therapy (ET) is a standard treatment option for ductal carcinoma in situ (DCIS). We sought to investigate national patterns in the use of adjuvant therapy after BCS for hormone receptor (HR)-positive DCIS over time.

PATIENTS AND METHODS

Using data from the National Cancer Data Base, we identified patients diagnosed with DCIS and treated with BCS between 2004 and 2013. Multivariable logistic regression was used to estimate the odds of adjuvant therapy use controlling for clinicopathologic demographic and facility-level characteristics.

RESULTS

We identified 66,079 patients who underwent BCS for DCIS. Overall, 21% received no adjuvant treatment, 71% received RT, 48% received ET, and 38% received the combination therapy. In adjusted analyses among the patients with HR-positive DCIS (n = 50,147), the administration of RT decreased (odds ratio [OR] 0.86, 95% CI 0.77-0.97), while the use of ET increased (OR 1.5, 95% CI 1.4-1.6) in 2013 compared to 2004. Young patients, elderly patients, positive margin status, and Medicare insurance were associated with lower use of both RT and ET. We observed both clinicopathologic and geographic variation in the use of adjuvant therapies. In the lowest risk subgroup, the use of RT decreased from 57% in 2004 to 48% in 2013 (OR 0.64, 95% CI 0.45-0.89).

CONCLUSION

Our study suggests a shift in patterns of care for DCIS that is impacted by both clinicopathologic and demographic factors, with the use of RT decreasing and the use of ET increasing in HR-positive DCIS patients. Current trials are designed to address the possible over-treatment of low-risk DCIS.