Patterns of use and short-term complications of breast brachytherapy in the national medicare population from 2008-2009

Use of Instrumental Variable Analyses for Evaluating Comparative Effectiveness in Empirical Applications of Oncology: A Systematic Review

PURPOSE

This systematic review aims to characterize the use and trends of instrumental variables (IVs) in oncology research, assess the quality and completeness of IV reporting, and evaluate the agreement and interpretation of IV results in comparison with other techniques used for determining comparative effectiveness in observational research.

METHODS

We performed a systematic search of observational empirical oncology papers evaluating the comparative effectiveness of cancer treatments using IV methods. EMBASE and MEDLINE (through June 2021) were used for a keyword search; Scopus and Web of Science were used for a citation search. Publication details and characteristics of IV analysis and reporting were extracted from each study to examine the uptake and quality of IV applications.

RESULTS

Sixty-five empirical papers were identified from February 2001 through June 2021. Geographic variation (50.8%) was the most common type of IV used, and the majority of IV applications constructed binary instruments (53.8%). Concurrent analyses using another non-IV method to adjust for confounding were conducted in 56 (86.2%) studies, 17 (30.4%) of which produced results divergent from IV approaches. We observed a modest uptake of IV methods between 2011 and 2021 together with its dissemination, which remained fairly limited to the United States (76.9%). The quality and completeness of IV reporting varied greatly. The underlying assumptions required for a valid IV analysis were only accounted for in full by 20 (30.8%) studies.

CONCLUSION

There are limited use and variable quality of IV analyses in oncology. Future research should look to establish standards to better facilitate the quality, transparency, and completeness of IV reporting in this setting.

Stereotactic partial breast irradiation in primary breast cancer: A comprehensive review of the current status and future directions

In selected low-risk breast cancer patients, accelerated partial breast irradiation (APBI) may represent an alternative option to the whole breast irradiation to reduce the volume of irradiated breast and total treatment duration. In the last few years, preliminary data from clinical trials showed that stereotactic partial breast radiotherapy may have the advantage to be less invasive compared to other APBI techniques, with preliminary good results in terms of local toxicity and cosmesis: the use of magnetic resonance, fiducial markers in the tumor bed, and new breast devices support both a precise definition of the target and radiation planning.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021257856, identifier CRD42021257856.

Influence of Geography on Prostate Cancer Treatment

PURPOSE

Several definitive treatment options are available for prostate cancer, but geographic access to those options is not uniform. We created maps illustrating provider practice patterns relation to patients and assessed the influence of distance to treatment receipt.

METHODS AND MATERIALS

The patient cohort was created by searching the National Medicare Database for patients diagnosed and treated for prostate cancer from 2011 to 2014. The provider cohort was created by querying the American Medical Association Physician Masterfile to identify physicians who had treated patients with prostatectomy, intensity modulated radiation therapy (IMRT), brachytherapy, stereotactic body radiation therapy (SBRT), or proton therapy. Maps detailing the location of providers were created for each modality. Multivariate multinomial logistic regressions were used to assess the association between patient-provider distance and probability of treatment.

RESULTS

Cohorts consisted of 89,902 patients treated by 5518 physicians. Substantial numbers of providers practicing established modalities (IMRT, prostatectomy, and brachytherapy) were noted in major urban centers, whereas provider numbers were reduced in rural areas, most notably for brachytherapy. Ninety percent of prostate cancer patients lived within 35.1, 28.9, and 55.6 miles of a practitioner of prostatectomy, IMRT, and brachytherapy, respectively. Practitioners of emerging modalities (SBRT and proton therapy) were predominantly concentrated in urban locations, with 90% of patients living within 128 miles (SBRT) and 374.5 miles (proton). Greater distance was associated with decreased probability of treatment (IMRT -3.8% per 10 miles; prostatectomy -2.1%; brachytherapy -2%; proton therapy -1.6%; and SBRT -1.1%).

CONCLUSIONS

Geographic disparities were noted for analyzed treatment modalities, and these disparities influenced delivery.

Persistent Use of Extended Fractionation Palliative Radiotherapy for Medicare Beneficiaries With Metastatic Breast Cancer, 2011 to 2014

INTRODUCTION

With no evidence to support extended radiation courses for the palliation of bone metastases, multiple guidelines were issued discouraging its use. We assessed contemporary use and cost of prolonged palliative radiotherapy in Medicare beneficiaries with bone metastases from breast cancer.

METHODS

We conducted a retrospective, longitudinal study of palliative radiotherapy use among fee-for-service Medicare beneficiaries with bone metastasis from breast cancer who underwent palliative radiotherapy during 2011 to 2014. Patients were categorized according to the number of days (fractions) on which they received palliative radiotherapy: 1, 2 to 10, 11 to 19, or 20 to 30. We examined the association of clinical, demographic, and provider characteristics with the use of extended (≥11 fractions) or very extended (≥20 fractions) fractionation with logistic regression models. We also compared the cost of different fractionation schemes from the payer perspective.

RESULTS

Of the 7547 patients in the sample (mean age, 71 y), 3084 (40.8%) received extended fractionation. The proportion of patients receiving 11 to 19 (34.7% in 2011 and 28.1% in 2014, trend P<0.001) and 20 to 30 treatments (10.3% in 2011 to 9.0% in 2014, trend P=0.07) decreased modestly over time. Patients with comorbidities were less likely to undergo extended fractionation (34.4% for ≥3 comorbidities vs. 44.9% for 0 comorbidities; adjusted odds ratio 0.67 [95% confidence interval, 0.58-0.76]). Patients treated at free-standing practices were more likely to undergo extended fractionation (47.9%) compared with those treated at hospital-based practices (37.3%, P<0.001; adjusted odds ratio, 1.49 [95% confidence interval, 1.35-1.65]). The mean cost of treatment varied from $633 (SD $240) for single-fraction treatment, to $3566 (SD $1349) for 11 to 19 fractions, to $6597 (SD $2893) for 20 to 30 fractions.

CONCLUSION

The use of prolonged courses of palliative radiotherapy among Medicare beneficiaries with breast cancer remained high in 2011 to 2014. The association between free-standing facility status and use of extended fractionation suggests that provider financial incentives may impact choice of treatment.

Accelerated partial breast irradiation-Redefining the treatment target for women with early stage breast cancer

Following breast conserving surgery, the standard of care has been to deliver adjuvant radiation therapy directed to the whole breast (WBI) over a period of 3-7 weeks. Over the past decade, increasing data have supported the concept that treatment to the whole breast may not be required in selected patients, allowing for the emergence of partial breast irradiation (PBI). Multiple randomized trials with 5-10 years of follow-up have been published documenting the safety and efficacy associated with PBI using multiple techniques. Questions that remain to be answered include (a) what is the optimal PBI technique for each clinical scenario, (b) are there additional patients that can be effectively managed with PBI approaches, and (c) are there different techniques/dose schedules that allow for further reduction in treatment duration and/or toxicities? Partial breast irradiation represents a standard approach for appropriately selected patients. PBI provides comparable clinical outcomes to WBI while allowing for a reduction in the duration treatment and the potential for reduced toxicities. Future studies may also help to better define which patients require no radiation, PBI, hypofractionated WBI or conventional WBI, based upon patient, clinical, pathologic features as well as potentially using tumor genetics.

Three-Fraction Intracavitary Accelerated Partial Breast Brachytherapy: Early Provider and Patient-Reported Outcomes of a Novel Regimen

PURPOSE

To report early adverse events and patient-reported outcomes (PROs) of 3-fraction intracavitary catheter-based partial breast brachytherapy (ICBB).

MATERIALS AND METHODS

Eligible women ≥50 years of age with ≤2.5-cm, lymph node-negative invasive or in situ breast cancer underwent breast-conserving surgery and placement of a brachytherapy applicator. ICBB was initiated on the second weekday after surgery and prescribed to 21 Gy in 3 once-daily fractions. Common Terminology Criteria for Adverse Events, version 4.0; 10-point linear analog scale assessment; the PRO version of the Common Terminology Criteria for Adverse Events; and the Harvard Breast Cosmesis Scale were used for provider and patient-reported assessments.

RESULTS

Seventy-three women were treated for invasive (79%) or in situ (21%) breast cancer. The median time to completion of surgery and radiation therapy was 6 days. After 14-months median follow-up, 2 patients (3%) had developed breast infections that resolved with oral antibiotics. There was no other treatment-associated adverse event grade ≥2. The grade 1 seroma rate at 3 months was 20%, which dropped to 8% at 12 months; no events required intervention. At 12 months, 91% of patients reported an overall quality of life score as ≥8 of 10, and patient-reported cosmesis was good or excellent in 95%. All patients are alive without relapse at the last follow-up.

CONCLUSIONS

Three-fraction ICBB is associated with low rates of early provider and patient- reported adverse events and compares favorably with early outcomes of more protracted ICBB regimens, including twice-daily (3.4 Gy × 10) fractionation studied in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39. Further investigation is warranted.

Association of Broad-Based Genomic Sequencing With Survival Among Patients With Advanced Non-Small Cell Lung Cancer in the Community Oncology Setting

IMPORTANCE

Broad-based genomic sequencing is being used more frequently for patients with advanced non-small cell lung cancer (NSCLC). However, little is known about the association between broad-based genomic sequencing and treatment selection or survival among patients with advanced NSCLC in a community oncology setting.

OBJECTIVE

To compare clinical outcomes between patients with advanced NSCLC who received broad-based genomic sequencing vs a control group of patients who received routine testing for EGFR mutations and/or ALK rearrangements alone.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of patients with chart-confirmed advanced NSCLC between January 1, 2011, and July 31, 2016, and who received care at 1 of 191 oncology practices across the United States using the Flatiron Health Database. Patients were diagnosed with stage IIIB/IV or unresectable nonsquamous NSCLC who received at least 1 line of antineoplastic treatment.

EXPOSURES

Receipt of either broad-based genomic sequencing or routine testing (EGFR and/or ALK only). Broad-based genomic sequencing included any multigene panel sequencing assay examining more than 30 genes prior to third-line treatment.

MAIN OUTCOMES AND MEASURES

Primary outcomes were 12-month mortality and overall survival from the start of first-line treatment. Secondary outcomes included frequency of genetic alterations and treatments received.

RESULTS

Among 5688 individuals with advanced NSCLC (median age, 67 years [interquartile range, 41-85], 63.6% white, 80% with a history of smoking); 875 (15.4%) received broad-based genomic sequencing and 4813 (84.6%) received routine testing. Among patients who received broad-based genomic sequencing, 4.5% received targeted treatment based on testing results, 9.8% received routine EGFR/ALK targeted treatment, and 85.1% received no targeted treatment. Unadjusted mortality rates at 12 months were 49.2% for patients undergoing broad-based genomic sequencing and 35.9% for patients undergoing routine testing. Using an instrumental variable analysis, there was no significant association between broad-based genomic sequencing and 12-month mortality (predicted probability of death at 12 months, 41.1% for broad-based genomic sequencing vs 44.4% for routine testing; difference -3.6% [95% CI, -18.4% to 11.1%]; P = .63). The results were consistent in the propensity score-matched survival analysis (42.0% vs 45.1%; hazard ratio, 0.92 [95% CI, 0.73 to 1.11]; P = .40) vs unmatched cohort (hazard ratio, 0.69 [95% CI, 0.62 to 0.77]; log-rank P < .001).

CONCLUSIONS AND RELEVANCE

Among patients with advanced non-small cell lung cancer receiving care in the community oncology setting, broad-based genomic sequencing directly informed treatment in a minority of patients and was not independently associated with better survival.

Partial breast irradiation with CyberKnife after breast conserving surgery: a pilot study in early breast cancer

BACKGROUND

Local recurrences after breast conserving treatment are mainly close to the original tumor site, and as such shorter fractionation strategies focused on and nearest mammary gland, i.e. accelerated partial breast irradiation (APBI), have been developed. Stereotactic APBI has been attempted, although there is little experience using CyberKnife (CK) for early breast cancer.

METHODS

This pilot study was designed to assess the feasibility of CK-APBI on 20 evaluable patients of 29 eligible, followed for 2 years. The primary endpoint was acute/sub-acute toxicity; secondary endpoints were late toxicity and the cosmetic result.

RESULTS

Mean pathological tumor size was 10.5 mm (±4.3, range 3-18), 8 of these patients were classified as LumA-like, 11 as LumB-like, and 1 as LumB-HER2-enriched. Using CK-APBI with Iris, the treatment time was approximately 60 min (range~ 35 to ~ 120). All patients received 30 Gy in five fractions delivered to the PTV. The median number of beams was 180 (IQR 107-213; range:56-325) with a median PTV isodose prescription of 86.0% (IQR 85.0-88.5; range:82-94). The median PTV was 88.1 cm3 (IQR 63.8-108.6; range:32.3-238.8). The median breast V100 and V50 was 0.6 (IQR 0.1-1.5; range:0-13) and 18.6 (IQR 13.1-21.7; range:7.5-37), respectively. The median PTV minimum dose was 26.2 Gy (IQR 24.7-27.6; range 22.3-29.3). Mild side effects were recorded during the period of observation. Cosmetic evaluations were performed by three observers from the start of radiotherapy up to 2 years. Patients' evaluation progressively increase from 60% to 85% of excellent rating; this trend was similar to that of external observer.

CONCLUSIONS

These preliminary results showed the safe feasibility of CK-APBI in early breast cancer, with mild acute and late toxicity and very good cosmetic results.

TRIAL REGISTRATION

The present study is registered at Clinicaltrial.gov ( NCT02896322 ). Retrospectively egistered August 4, 2016.

Quality Of Breast Cancer Care In The US Territories: Insights From Medicare

The quality of breast cancer care among Medicare beneficiaries in the US territories-where federal spending for health care is lower than in the continental US-is unknown. We compared female Medicare beneficiaries who were residents of the US territories and had surgical treatment for breast cancer in 2008-14 to those in the continental US in terms of receipt of recommended breast cancer care (diagnostic needle biopsy and adjuvant radiation therapy [RT] following breast-conserving surgery) and the timeliness (time from needle biopsy to surgery and from surgery to adjuvant RT) of that care. Residents of the US territories were less likely to receive recommended care (24 percent lower odds of receiving diagnostic needle biopsy and 34 percent lower odds of receiving adjuvant RT) and to receive timely care (45 percent lower odds of receiving surgery and 82 percent lower odds of receiving adjuvant RT, both within three months). Further research is needed to identify barriers to the provision of adequate and timely breast cancer care in this unique population.

New Breast Cancer Radiotherapy Technology Confers Higher Complications and Costs Before Effectiveness Proven: A Medicare Data Analysis

A new breast cancer treatment, brachytherapy-based accelerated partial breast radiotherapy (RT), was adopted before long-term effectiveness evidence, potentially increasing morbidity and costs compared with whole breast RT. The aim of this study was to estimate complication rates and RT-specific and 1-year costs for a cohort of female Medicare beneficiaries diagnosed with breast cancer (N = 47 969). We analyzed 2005-2007 Medicare claims using multivariable logistic regression for complications and generalized linear models (log link, gamma distribution) for costs. Overall, 11% (n = 5296) underwent brachytherapy-based RT; 9.4% had complications. Odds of any complication were higher (odds ratio [OR]: 1.62; 95% confidence interval [CI]: 1.49-1.76) for brachytherapy versus whole breast RT, similarly to seroma (OR: 2.85; 95% CI: 1.97-4.13), wound complication/infection (OR: 1.72; 95% CI: 1.52-1.95), cellulitis (OR: 1.48; 95% CI: 1.27-1.73), and necrosis (OR: 2.07; 95% CI: 1.55-2.75). Mean RT-specific and 1-year total costs for whole breast RT were $6375, and $19 917, $4886, and $4803 lower than brachytherapy ( P < .0001). Multivariable analyses indicated brachytherapy yielded 76% higher RT costs (risk ratio: 1.76; 95% CI: 1.74-1.78, P < .0001) compared with whole breast RT. Brachytherapy had higher complications and costs before long-term evidence proved its effectiveness. Policies should require treatment registries with reimbursement incentives to capture surveillance data for new technologies.

Long term radiographic findings of breast brachytherapy: Implications of surgical volume

PURPOSE

Little is known about long-term radiographic findings after treatment with accelerated partial breast irradiation (APBI).

METHODS

Univariate and multivariate analysis of factors leading to formation and resolution of seroma were performed in patients treated with lumpectomy and APBI.

RESULTS

Post-treatment images of 129 patients were reviewed by one radiologist. Median surgical excision volume was 108.9 cc (range 20.5-681.9). Primary mode of imaging was mammogram. Median time from end of RT to first and last surveillance image was 6 and 54 months, respectively. Median number of images was 7 (range 3-12). Seroma was identified in 98 (76%) patients, with median maximum diameter of 3.9 cm. Forty (41%) patients experienced resolution of seroma, at a median time of 29 months (range 6-74). On univariate analysis, surgical excision volume was associated with seroma formation, and tumor stage and margin re-excision were significant on univariate and multivariate analysis. No factors were associated with seroma resolution.

CONCLUSION

Seroma formation after APBI resolves around 2.5 years for many patients, but persists for others possibly due to primary tumor and surgical excision volumes. With revised criteria on the definition of positive margins, smaller volumes may lead to decreased risk of seroma formation for future patients.

Trends in the use of implantable accelerated partial breast irradiation for ductal carcinoma in situ: Implications of the recent amendments to the American Society for Radiation Oncology consensus guidelines

PURPOSE

In 2009, the American Society for Radiation Oncology (ASTRO) published consensus recommendations that stated ductal carcinoma in situ (DCIS) patients were in a "cautionary" group for accelerated partial breast irradiation (APBI) and should not receive APBI outside of a clinical trial. However, very recently, ASTRO placed low-risk DCIS patients in the "suitable" category. Given this recent change, we aimed to use the Surveillance, Epidemiology, and End Results (SEER) database to evaluate past patterns of implantable APBI (IAPBI) utilization in women with DCIS.

METHODS AND MATERIALS

The Surveillance, Epidemiology, and End Results database was queried for patients from 2000 to 2012 with DCIS that underwent lumpectomy and adjuvant radiation therapy. Patients receiving IAPBI were differentiated from those receiving whole breast radiation therapy. Trends based on treatment year and patient demographics were collected, and multivariable logistic regression determined factors independently predictive of use of IAPBI.

RESULTS

Of 52,012 eligible patients, 49,450 (95%) underwent external beam radiation and 2562 (5%) received APBI. Though IAPBI utilization steadily increased from 2000 (0.2% of the study population) to 2008 (9.4%), it abruptly declined in 2009 (7.9%, p = 0.009) and yearly thereafter. The 40-49 age group was proportionally most associated with this decline (8.6% in 2008 to 4.3% in 2009). Factors independently associated with IAPBI receipt included increasing age, hormone receptor negative status, and women living in the South.

CONCLUSIONS

Patterns of IAPBI administration in DCIS are described. These trends are important to consider as a benchmark going forward, in light of the very recent change in ASTRO recommendations to include low-risk DCIS patients.

Survival after Breast-Conserving Surgery with Whole Breast or Partial Breast Irradiation in Women with Early Stage Breast Cancer: A SEER Data-base Analysis

Randomized clinical trials have demonstrated equivalency in survival outcomes for early stage breast cancer patients treated with either mastectomy or breast-conserving surgery (BCS) with radiation. Recent, state-level data confirm comparable survival outcomes. Using Surveillance Epidemiology and End Research (SEER) data, we sought to evaluate survival outcomes among patients with early stage breast cancer treated with mastectomy, BCS with whole breast irradiation (BCS + WBI), or BCS with accelerated partial breast irradiation (BCS + APBI). Data on women 50 years or older diagnosed with a node negative invasive breast cancer (≤3 cm in size) between 1995 and 2009 were extracted from the SEER data base. Women treated with mastectomy alone or BCS with radiation were eligible for analysis. Kaplan-Meier estimates and Cox proportional hazard models were used to compare overall survival (OS) and cancer-specific survival (CSS) among the treatment groups. 150,171 women fulfilled inclusion criteria. OS was significantly improved among women treated with BCS and WBI or BCS and APBI compared to mastectomy alone. Adjusted hazard ratios for death in BCS with WBI or APBI (versus mastectomy alone) were 0.73 (95% CI: 0.71, 0.76) and 0.68 (95% CI: 0.58, 0.79), respectively. Adjusted CSS was also significantly improved in patients treated with BCS and WBI (HR 0.80, 95% CI: 0.76, 0.85) as compared to mastectomy. BCS with radiation (WBI or APBI) was associated with significantly improved OS and CSS, versus mastectomy alone. These results support the use of BCS with WBI or APBI (in well selected patients) for the treatment of breast cancer.

Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

PURPOSE

We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients.

METHODS AND MATERIALS

Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events.

RESULTS

A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator). The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased infectious and noninfectious adverse events. The 5-year incidences of fat necrosis, breast pain, and rib fracture were slightly higher after brachytherapy than after EBRT (13.7% vs 8.1%, 19.4% vs 16.0%, and 1.6% vs 1.3%, respectively), but the risks were not significantly different for multichannel versus single-channel applicators.

CONCLUSION

Toxicities after breast brachytherapy were distinct from those after EBRT. Temporal toxicity trends may reflect changing technology and evolving practitioner experience with brachytherapy.

Accelerated partial breast irradiation: a review and evaluation of indications for treatment

Accelerated partial breast irradiation (APBI) represents a well-studied treatment modality for the delivery of adjuvant radiation therapy following breast-conserving surgery. Interstitial APBI represents the APBI technique with the longest follow-up to date; data from randomized trials and matched pair analyses demonstrate equivalent local control to traditional whole-breast irradiation with comparable rates of toxicity and improved cosmesis. While less mature, prospective data support the efficacy and safety of applicator-based brachytherapy with new multilumen applicators offering the potential for improved outcomes. External beam APBI represents a noninvasive technique; however, concerns regarding toxicity with this technique have emerged though newer techniques may mitigate these concerns. Multiple guidelines have been published based on traditional clinical and pathologic criteria to help physicians offer APBI to appropriately selected patients.

Targeted Intraoperative Radiotherapy for the Management of Ductal Carcinoma In Situ of the Breast

Multiple long-term studies have demonstrated a propensity for breast cancer recurrences to develop near the site of the original breast cancer. Recognition of this local recurrence pattern laid the foundation for the development of accelerated partial breast irradiation (APBI) approaches designed to limit the radiation treatment field to the site of the malignancy. However, there is a paucity of data regarding the efficacy of APBI in general, and intraoperative radiotherapy (IORT), in particular, for the management of ductal carcinoma in situ (DCIS). As a result, use of APBI, remains controversial. A prospective nonrandomized trial was designed to determine if patients with pure DCIS considered eligible for concurrent IORT based on preoperative mammography and contrast-enhanced magnetic resonance imaging (CE-MRI) could be successfully treated using IORT with minimal need for additional therapy due to inadequate surgical margins or excessive tumor size. Between November 2007 and June 2014, 35 women underwent bilateral digital mammography and bilateral breast CE-MRI prior to selection for IORT. Patients were deemed eligible for IORT if their lesion was ≤4 cm in maximal diameter on both digital mammography and CE-MRI, pure DCIS on minimally invasive breast biopsy or wide local excision, and considered resectable with clear surgical margins using breast-conserving surgery (BCS). Postoperatively, the DCIS lesion size determined by imaging was compared with lesion size and surgical margin status obtained from the surgical pathology specimen. Thirty-five patients completed IORT. Median patient age was 57 years (range 42-79 years) and median histologic lesion size was 15.6 mm (2-40 mm). No invasive cancer was identified. In more than half of the patients in our study (57.1%), MRI failed to detect a corresponding lesion. Nonetheless, 30 patients met criteria for negative margins (i.e., margins ≥2 mm) whereas five patients had positive margins (<2 mm). Two of the five patients with positive margins underwent mastectomy due to extensive imaging-occult DCIS. Three of the five patients with positive margins underwent successful re-excision at a subsequent operation prior to subsequent whole breast irradiation. A total of 14.3% (5/35) of patients required some form of additional therapy. At 36 months median follow-up (range of 2-83 months, average 42 months), only two patients experienced local recurrences of cancer (DCIS only), yielding a 5.7% local recurrence rate. No deaths or distant recurrences were observed. Imaging-occult DCIS is a challenge for IORT, as it is for all forms of breast-conserving therapy. Nonetheless, 91.4% of patients with DCIS were successfully managed with BCS and IORT alone, with relatively few patients requiring additional therapy.

Comparison of chronic toxicities between brachytherapy-based accelerated partial breast irradiation and whole breast irradiation using intensity modulated radiotherapy

PURPOSE

Brachytherapy-based APBI (bAPBI) shortens treatment duration and limits dose to normal tissue. While studies have demonstrated similar local control when comparing bAPBI and whole breast irradiation using intensity modulated radiotherapy (WBI-IMRT), comparison of late side effects is limited. Here, we report chronic toxicity profiles associated with these two treatment modalities.

METHODS

1034 patients with early stage breast cancer were treated at a single institution; 489 received standard-fractionation WBI-IMRT between 2000 and 2013 and 545 received bAPBI (interstitial 40%, applicator-based 60%) between 1993 and 2013. Chronic toxicity was evaluated ≥6 months utilizing CTCAE version 3.0; cosmesis was evaluated using the Harvard scale.

RESULTS

Median follow-up was 4.6 years (range 0.1-13.4) for WBI-IMRT versus 6.7 years (range 0.1-20.1) for bAPBI (p < 0.001). Compared to WBI-IMRT, bAPBI was associated with higher rates of ≥grade 2 seroma formation (14.4% vs 2.9%, p < 0.001), telangiectasia (12.3% vs 2.1%, p = 0.002) and symptomatic fat necrosis (10.2% vs 3.6%, p < 0.001). Lower rates of hyperpigmentation were observed (5.8% vs 14.5%; p = 0.001). Infection rates were similar (3.3% vs 1.3%, p = 0.07). There was no difference between rates of fair (6.1% vs. 4.1%, p = 0.30) or poor (0.2% vs. 0.5%, p = NS) cosmesis. Mastectomy rates for local recurrence (3.1% for WBI-IMRT and 1.2% for bAPBI, p = 0.06), or for other reasons (0.8% and 0.6%, p = 0.60) were similar between groups.

CONCLUSION

With 5-year follow-up, WBI-IMRT and bAPBI are associated with similar, acceptable rates of toxicity. These data further support the utilization of bAPBI as a modality to deliver adjuvant radiation in a safe and efficacious manner.

Physician's peer exposure and the adoption of a new cancer treatment modality

BACKGROUND

New technologies, often with limited evidence to support their effectiveness, frequently diffuse into clinical practice and increase the costs of cancer care. The authors studied whether physician peer exposure was associated with the subsequent adoption of a new approach to adjuvant radiotherapy (brachytherapy) for the treatment of women with early-stage breast cancer.

METHODS

A retrospective cohort study was performed using Surveillance, Epidemiology, and End Results (SEER)-Medicare data. Data from 2003 through 2004 were used to classify surgeons as early brachytherapy adopters and, among non-early adopters, whether they shared patients with early adopters (peer exposure). Data from 2005 through 2006 were used to examine whether women were more likely to receive brachytherapy if their surgeons were exposed to early adopters.

RESULTS

Overall, the percentage of women receiving brachytherapy increased from 3.2% in 2003 through 2004 to 4.7% in 2005 through 2006. In this latter period, a total of 2087 patients were assigned to 328 non-early adopting surgeons. In unadjusted analyses, patients whose surgeons were connected to early adopters during 2003 through 2004 were found to be significantly more likely to receive brachytherapy in 2005 through 2006 compared with those whose surgeons were not connected to early adopters (8.0% vs 4.1%; P = .003). In adjusted analyses, the predicted probability of receiving brachytherapy among patients whose surgeon did have an early-adopting peer was 3.9% versus 1.0% among those whose surgeons did not have an early-adopting peer (P = .03).

CONCLUSIONS

Exposure to peers who were early adopters of brachytherapy was found to be associated with a surgeon's subsequent uptake of brachytherapy. The results of the current study provide an example of a novel approach to examining the diffusion of innovation in cancer care.

The Role of Patient Factors, Cancer Characteristics, and Treatment Patterns in the Cost of Care for Medicare Beneficiaries with Breast Cancer

OBJECTIVE

To characterize Medicare expenditures on initial breast cancer care and examine variation in expenditures across hospital referral regions (HRRs).

DATA SOURCE

We identified 29,110 women with localized breast cancer diagnosed in 2005-2008 and matched controls from the Surveillance, Epidemiology, and End Results-Medicare linked database.

STUDY DESIGN

Using hierarchical generalized linear models, we estimated per patient Medicare expenditure on initial breast cancer care across HRRs and assessed the contribution of patient, cancer, and treatment factors to regional variation via incremental models.

PRINCIPAL FINDINGS

Mean Medicare expenditure for initial breast cancer care was $19,255 per patient. The average expenditures varied from $15,053 in the lowest-spending HRR quintile to $23,480 in the highest-spending HRR quintile. Patient sociodemographic, comorbidity, and tumor characteristics explained only 1.8 percent of the difference in expenditures between the lowest- and highest-spending quintiles, while use of specific treatment modalities explained 14.5 percent of the difference. Medicare spending on radiation therapy differed the most across the quintiles, with the use of intensity modulated radiation therapy increasing from 1.7 percent in the lowest-spending quintile to 11.6 percent in the highest-spending quintile.

CONCLUSIONS

Medicare expenditures on initial breast cancer care vary substantially across regions. Treatment factors are major contributors to the variation.

Utilization and Outcomes of Breast Brachytherapy in Younger Women

PURPOSE

To directly compare (1) radiation treatment utilization patterns; (2) risks of subsequent mastectomy; and (3) costs of radiation treatment in patients treated with brachytherapy versus whole-breast irradiation (WBI), in a national, contemporary cohort of women with incident breast cancer, aged 64 years and younger.

METHODS AND MATERIALS

Using MarketScan health care claims data, we identified 45,884 invasive breast cancer patients (aged 18-64 years), treated from 2003 to 2010 with lumpectomy, followed by brachytherapy (n = 3134) or whole-breast irradiation (n = 42,750). We stratified patients into risk groups according to age (Age < 50 vs Age ≥ 50) and endocrine therapy status (Endocrine- vs Endocrine+). "Endocrine+" patients filled an endocrine therapy prescription within 1 year after lumpectomy. Pathologic hormone receptor status was not available in this dataset. In brachytherapy versus WBI patients, utilization trends and 5-year subsequent mastectomy risks were compared. Stratified, adjusted subsequent mastectomy risks were calculated using proportional hazards regression.

RESULTS

Brachytherapy utilization increased from 2003 to 2010: in patients Age < 50, from 0.6% to 4.9%; patients Age ≥ 50 from 2.2% to 11.3%; Endocrine- patients, 1.3% to 9.4%; Endocrine+ patients, 1.9% to 9.7%. Age influenced treatment selection more than endocrine status: 17% of brachytherapy patients were Age < 50 versus 32% of WBI patients (P < .001); whereas 41% of brachytherapy patients were Endocrine-versus 44% of WBI patients (P = .003). Highest absolute 5-year subsequent mastectomy risks occurred in Endocrine-/Age < 50 patients (24.4% after brachytherapy vs 9.0% after WBI (hazard ratio [HR] 2.18, 95% confidence interval [CI] 1.37-3.47); intermediate risks in Endocrine-/Age ≥ 50 patients (8.6% vs 4.9%; HR 1.76, 95% CI 1.26-2.46); and lowest risks in Endocrine+ patients of any age: Endocrine+/Age < 50 (5.5% vs 4.5%; HR 1.18, 95% CI 0.61-2.31); Endocrine+/Age ≥ 50 (4.2% vs 2.4%; HR 1.71, 95% CI 1.16-2.51).

CONCLUSION

In this younger cohort, endocrine status was a valuable discriminatory factor predicting subsequent mastectomy risk after brachytherapy versus WBI and therefore may be useful for selecting appropriate younger brachytherapy candidates.

The incidence of fat necrosis in balloon-based breast brachytherapy

Purpose

To investigate the incidence of and potential risk factors for fat necrosis in high dose-rate (HDR) balloon-based breast brachytherapy (BBB).

Material and methods

Fifty-four patients were treated postoperatively with HDR-BBB between May 2007 and December 2010. Median age was 71 years (range: 50-88 years). Median tumor size was 1 cm (range: 0.1-2.7 cm). Forty-four had invasive histology; 43% were grade 1, 24% grade 2, and 15% grade 3. The median margin size was 0.7 cm (range: 0.1-1.5 cm).

Results

With a median follow-up of 2.9 years (range: 0.5-5.2 years), local control was 98% with one in-breast failure, and overall survival was 89%. Fifty percent of patients experienced fat necrosis. Seven patients were symptomatic, with the remainder detected by mammography alone. Two patients required surgical resection with pathology confirming fat necrosis; 1 required i.v. steroids. At 1, 3, and 5 years following treatment, estimated cumulative incidences of fat necrosis were 7.5%, 52.7%, and 60.6%. Breast laterality, location, tumor size, histology, margin size, balloon volume, skin distance, skin dose, and number of dwell positions were not significantly associated with fat necrosis on univariate analysis.

Conclusions

In this retrospective review of HDR-BBB, we found a 50% incidence of both asymptomatic and symptomatic fat necrosis. Only three patients, however, required intervention. None of the risk factors considered were significantly associated with fat necrosis. Further studies evaluating factors associated with fat necrosis for patients undergoing HDR-BBB are necessary to appropriately assess the risks associated with treatment.

How can we best respect patient autonomy in breast cancer treatment decisions?

Helping patients to maximize their autonomy in breast cancer decision-making is an important aspect of patient-centered care. Shared decision-making is a strategy that aims to maximize patient autonomy by integrating the values and preferences of the patient with the biomedical expertise of the physician. Application of this approach in breast cancer decision-making has not been uniform across cancer-specific interventions (e.g., surgery, chemotherapy), and in some circumstances may present challenges to evidence-based care delivery. Increasingly precise estimates of individual patients' risk of recurrence and commensurate predicted benefit from certain therapies hold significant promise in helping patients exercise autonomous decision-making for their breast cancer care, yet will also likely complicate decision-making for certain subgroups of patients.

Diffusion of accelerated partial breast radiotherapy in the United States: physician-level and patient-level analyses

PURPOSE

To evaluate diffusion of brachytherapy-based accelerated partial breast radiotherapy (RT) in the United States, a new breast cancer treatment requiring 5 days twice daily, rather than daily treatment for 6-7 weeks. It has limited long-term effectiveness data compared with standard whole breast RT.

DATA AND METHODS

We used 2005-2008 Medicare claims for female Medicare beneficiaries receiving RT after breast-conserving surgery merged with physician and area-based data (n=74,254 patient-subjects; n=1901 physicians), applying logistic regression to estimate: (1) proportion of patients for whom the radiation oncologist used brachytherapy-based accelerated RT, and (2) probability a patient received brachytherapy-based accelerated RT, clustering on physician.

RESULTS

Use of accelerated partial breast RT increased over time (8% in 2005 to 17% in 2008). Physician-level analysis indicates rural physicians were less likely to perform accelerated RT [odds ratio (OR): 0.35-0.49; P<0.002)]; as were those licensed 20+years [OR: 0.54; 95% confidence interval (CI), 0.39-0.74]. Overall, 11.7% of patients received accelerated RT. Treatment post 2005 was associated with increasing odds of receiving accelerated RT (P<0.0001). Older age was associated with lower odds of receiving accelerated RT (reference, 66-69 years old, OR: 0.90, P<0.006), as was black (OR: 0.73;95% CI, 0.63-0.85) or other race (OR: 0.80; 95% CI, 0.65-1.00), living in rural areas (OR: 0.8; P<0.0001), or seeing an older physician [20+years postgraduation (OR: 0.7; 95% CI, 0.5-0.9)]. Patients living in counties with more hospitals with advanced RT facilities were more likely to undergo accelerated RT (OR: 1.4; 95% CI, 1.1-1.8).

DISCUSSION

This new technology appears to be in the early phase of diffusion across the United States and is more rapidly being taken up in younger, white patients living in urban and suburban areas with availability of advanced RT facilities. Rural and older patient populations are not tending to undergo the treatment.

Considerations for observational research using large data sets in radiation oncology

The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based data sets. With the growing emphasis on observational analyses in health care, the radiation oncology community must possess a sophisticated understanding of the methodological considerations of such studies in order to evaluate evidence appropriately to guide practice and policy. Because observational research has unique features that distinguish it from clinical trials and other forms of traditional radiation oncology research, the International Journal of Radiation Oncology, Biology, Physics assembled a panel of experts in health services research to provide a concise and well-referenced review, intended to be informative for the lay reader, as well as for scholars who wish to embark on such research without prior experience. This review begins by discussing the types of research questions relevant to radiation oncology that large-scale databases may help illuminate. It then describes major potential data sources for such endeavors, including information regarding access and insights regarding the strengths and limitations of each. Finally, it provides guidance regarding the analytical challenges that observational studies must confront, along with discussion of the techniques that have been developed to help minimize the impact of certain common analytical issues in observational analysis. Features characterizing a well-designed observational study include clearly defined research questions, careful selection of an appropriate data source, consultation with investigators with relevant methodological expertise, inclusion of sensitivity analyses, caution not to overinterpret small but significant differences, and recognition of limitations when trying to evaluate causality. This review concludes that carefully designed and executed studies using observational data that possess these qualities hold substantial promise for advancing our understanding of many unanswered questions of importance to the field of radiation oncology.

Decision to Adopt Medical Technology

Objective. To understand decision making concerning adoption and nonadoption of accelerated partial breast radiotherapy (RT) prior to long-term randomized trial evidence. Methods. A total of 36 radiation oncologists and surgeons were recruited through purposive and snowball sampling strategies from September 2010 through January 2013. Semistructured phone interviews were conducted and audio-recorded and lasted 20–45 minutes. Qualitative analysis was conducted using a framework approach, iteratively exploring key concepts and emerging issues raised by subjects. Interviews were transcribed and imported into Atlas.ti v6. Transcripts were independently coded by 3 researchers shortly after each interview, followed by consensus development on each coded transcript. Barriers and facilitators of adoption, practice patterns, and informational/educational sources concerning accelerated partial breast RT were all assessed to determine major themes. Results. Nearly half of physicians were surgeons (47%), and half were radiation oncologists (53%), with 61% overall in urban settings. Twenty-nine of the 36 physicians interviewed used brachytherapy-based partial breast RT. Five major factors were involved in physicians’ decisions to adopt accelerated partial breast RT: facilitators encouraging adoption (e.g., enthusiastic colleagues and patient convenience), financial and prestige incentives, pressures to adopt (e.g., potential declines in referrals), judgment concerning acceptable level of scientific evidence, and barriers (e.g., not having appropriate machinery or referral mechanism in place). If technology was adopted, clinical guideline adherence varied. Conclusions. Technology adoption is based on financial and social pressures, along with often-limited scientific evidence and what seems “best” for patients. For technology adoption and diffusion to be rational and evidence-based, we must encourage appropriate financial payment models to curb use outside of research studies and promote development of additional treatment registries until sufficient evidence is gathered.

[State of the art and perspectives of accelerated partial breast irradiation in 2014]

In the frame of treatment de-escalation and personalization, accelerated partial breast irradiation is taking its place in the breast cancer therapeutic options. This study analyzed the results of phase III randomized trials having compared accelerated partial breast irradiation versus whole breast irradiation. Currently, among those trails, six proposed some results regarding efficacy and/or toxicity. Globally, the non-randomized studies confirmed the expected results showing a low rate of local recurrence and toxicity. The first results of the phase III randomized trials showed encouraging data in terms of local control while the toxicity varied mainly according to the accelerated partial breast irradiation technique used. However, the follow-up of the majority of these studies remains insufficient. The strict respect of accelerated partial breast irradiation indications likely represents one of the key factors of the therapeutic success. The next results could allow proposing a better definition of the accelerated partial breast irradiation selection criteria.

Increased use of partial-breast irradiation has not improved radiotherapy utilization for early-stage breast cancer

BACKGROUND

Radiotherapy (RT) reduces local recurrence after breast-conserving surgery (BCS) for breast cancer, but under-utilization of RT has been reported. Accelerated partial-breast irradiation (PBI) improves RT accessibility, but it is uncertain if this has improved RT utilization.

METHODS

The Surveillance, Epidemiology and End Results registry was used to identify women who underwent BCS for stage 0 or 1 breast cancer from 2000 to 2009. Temporal trends in RT utilization and RT modality were determined. Chi-square analysis and multivariate logistic regression identified predictors of RT utilization and modality.

RESULTS

Of 180,219 study patients, 131,343 (73 %) received RT; 123,703 (94 %) of RT recipients received whole-breast irradiation (WBI) and 6,251 (5 %) received PBI. PBI rates increased dramatically during the study period (0.32 % in 2000 vs. 6.5 % in 2009), but overall RT utilization remained relatively stable because of a decline in WBI (69.8 % in 2000 vs. 62.4 % in 2009). RT utilization was unchanged in rural counties, and declined for women <40 and ≥70 years of age, and for Native American, Asian and Hispanic patients. White and Black women used PBI most frequently (4 % each) and were the only race groups with improved RT utilization over time. Predictors of RT usage included age, race, marital status, tumor size, grade, hormone receptor status, lymph node evaluation, geographic region, metropolitan status, education, and employment status.

CONCLUSIONS

Women who undergo RT are opting for PBI more frequently, but the increased use of this modality has not improved overall RT utilization for patients with early-stage breast cancer.

Balloon brachytherapy for breast cancer prove that it works? Or, prove that it doesn't?

Balloon breast brachytherapy is a catheter-based technique to deliver high local concentration of radiation following breast-sparing surgery. Although this technique is logically appealing--providing more directed radiation to sites at high risk of local failure--there remains little empirical support that this intervention is non-inferior to external beam radiotherapy, a well-established standard. Additionally, observational studies suggest that balloon brachytherapy is associated with high rates of local complications, and higher rates of subsequent mastectomy, a marker of local failure. Here, I explore regulatory and clinical considerations that lead to the widespread adoption of breast brachytherapy. I argue that the therapy spread before its efficacy was confirmed. Breast brachytherapy illustrates ongoing complexities in the approval of novel devices.

For-profit hospital ownership status and use of brachytherapy after breast-conserving surgery

BACKGROUND

Little is known about the relationship between operative care for breast cancer at for-profit hospitals and subsequent use of adjuvant radiation therapy (RT). Among Medicare beneficiaries, we examined whether hospital ownership status is associated with the use of breast brachytherapy--a newer and more expensive modality--as well as overall RT.

METHODS

We conducted a retrospective study of female Medicare beneficiaries who received breast-conserving surgery for invasive breast cancer in 2008 and 2009. We assessed the relationship between hospital ownership and receipt of brachytherapy or overall RT by using hierarchical generalized linear models.

RESULTS

The sample consisted of 35,118 women, 8.0% of whom had breast-conserving operations at for-profit hospitals. Among patients who received RT, those who underwent operation at for-profit hospitals were more likely to receive brachytherapy (20.2%) than patients treated at not-for-profit hospitals (15.2%; odds ratio [OR] for for-profit versus not-for-profit: 1.50; 95% confidence interval [95% CI] 1.23-1.84; P < .001). Among women aged 66-79 years, there was no relationship between hospital ownership status and overall use of RT. Among women ages 80-94 years of age--the group least likely to benefit from RT due to shorter life expectancy--undergoing breast-conserving operations at a for-profit hospital was associated with greater overall use of RT (OR 1.22; 95% CI 1.03-1.45, P = .03) and brachytherapy use (OR 1.66; 95% CI 1.18-2.34, P = .003).

CONCLUSION

Operative care at for-profit hospitals was associated with increased use of the newer and more expensive RT modality, brachytherapy. Among the oldest women who are least likely to benefit from RT, operative care at a for-profit hospital was associated with greater overall use of RT, with this difference largely driven by the use of brachytherapy.

Examining the cost-effectiveness of radiation therapy among older women with favorable-risk breast cancer

BACKGROUND

Little is known about the cost-effectiveness of external beam radiation therapy (EBRT) or newer radiation therapy (RT) modalities such as intensity modulated radiation (IMRT) or brachytherapy among older women with favorable-risk breast cancer.

METHODS

Using a Markov model, we estimated the cost-effectiveness of no RT, EBRT, and IMRT over 10 years. We estimated the incremental cost-effectiveness ratio (ICER) of IMRT compared with EBRT under different scenarios to determine the necessary improvement in effectiveness for newer modalities to be cost-effective. We estimated model inputs using women in the Surveillance, Epidemiology, and End Results-Medicare database fulfilling the Cancer and Leukemia Group B C9343 trial criteria.

RESULTS

The incremental cost of EBRT compared with no RT was $9500 with an ICER of $44600 per quality-adjusted life year (QALY) gained. The ICERs increased with age, ranging from $38300 (age 70-74 years) to $55800 (age 80 to 94 years) per QALY. The ICERs increased to more than $63800 per QALY for women aged 70 to 74 years with an expected 10-year survival of 25%. Reduction in local recurrence by IMRT compared with EBRT did not have a substantial impact on the ICER of IMRT. IMRT would have to increase the utility of baseline state by 20% to be cost-effective (<$100000 per QALY).

CONCLUSIONS

EBRT is cost-effective for older women with favorable risk breast cancer, but substantially less cost-effective for women with shorter expected survival. Newer RT modalities would have to be substantially more effective than existing therapies in improving quality of life to be cost-effective.