Evaluating radiotherapy options in breast cancer: does intraoperative radiotherapy represent the most cost-efficacious option?

INTRODUCTION

This study analyzed the cost-efficacy of intraoperative radiation therapy (IORT) compared with whole-breast irradiation (WBI) and accelerated partial-breast irradiation (APBI) for early-stage breast cancer.

MATERIALS AND METHODS

Data for this analysis came from 2 phase III trials: the TARGIT (Targeted Intraoperative Radiotherapy) trial and the ELIOT (Electron Intraoperative Radiotherapy) trial. Cost analyses included a cost-minimization analysis and an incremental cost-effectiveness ratio analysis including a quality-adjusted life-year (QALY) analysis. Cost analyses were performed comparing IORT with WBI delivered using 3-dimensional conformal radiotherapy (3D-CRT), APBI 3D-CRT, APBI delivered with intensity-modulated radiotherapy (IMRT), APBI single-lumen (SL), APBI multilumen (ML), and APBI interstitial (I).

RESULTS

Per 1000 patients treated, the cost savings with IORT were $3.6-$4.3 million, $1.6-$2.4 million, $3.6-$4.4 million, $7.5-$8.2 million, and $2.8-$3.6 million compared with WBI 3D-CRT, APBI IMRT, APBI SL, APBI ML, and APBI I, respectively, with a cost decrement of $1.6-$2.4 million compared with APBI 3D-CRT based on data from the TARGIT trial. The costs per QALY for WBI 3D-CRT, APBI IMRT, APBI SL, APBI ML, and APBI I compared with IORT were $47,990-$60,002; $17,335-$29,347; $49,019-$61,031; $108,162-$120,173; and $36,129-$48,141, respectively, based on data from the ELIOT trial. These results are consistent with APBI and WBI being cost-effective compared with IORT.

CONCLUSION

Based on cost-minimization analyses, IORT represents a potential cost savings in the management of early-stage breast cancer. However, absolute reimbursement is misleading, because when additional medical and nonmedical costs associated with IORT are factored in, WBI and APBI represent cost-effective modalities based on cost-per-QALY analyses. They remain the standard of care.

Late toxicity and patient self-assessment of breast appearance/satisfaction on RTOG 0319: a phase 2 trial of 3-dimensional conformal radiation therapy-accelerated partial breast irradiation following lumpectomy for stages I and II breast cancer

PURPOSE

Late toxicities and cosmetic analyses of patients treated with accelerated partial breast irradiation (APBI) on RTOG 0319 are presented.

METHODS AND MATERIALS

Patients with stages I to II breast cancer ≤3 cm, negative margins, and ≤3 positive nodes were eligible. Patients received three-dimensional conformal external beam radiation therapy (3D-CRT; 38.5 Gy in 10 fractions twice daily over 5 days). Toxicity and cosmesis were assessed by the patient (P), the radiation oncologist (RO), and the surgical oncologist (SO) at 3, 6, and 12 months from the completion of treatment and then annually. National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to grade toxicity.

RESULTS

Fifty-two patients were evaluable. Median follow-up was 5.3 years (range, 1.7-6.4 years). Eighty-two percent of patients rated their cosmesis as good/excellent at 1 year, with rates of 64% at 3 years. At 3 years, 31 patients were satisfied with the treatment, 5 were not satisfied but would choose 3D-CRT again, and none would choose standard radiation therapy. The worst adverse event (AE) per patient reported as definitely, probably, or possibly related to radiation therapy was 36.5% grade 1, 50% grade 2, and 5.8% grade 3 events. Grade 3 AEs were all skin or musculoskeletal-related. Treatment-related factors were evaluated to potentially establish an association with observed toxicity. Surgical bed volume, target volume, the number of beams used, and the use of bolus were not associated with late cosmesis.

CONCLUSIONS

Most patients enrolled in RTOG 0319 were satisfied with their treatment, and all would choose to have the 3D-CRT APBI again.

Breast-cancer related lymphedema: a review of procedure-specific incidence rates, clinical assessment AIDS, treatment paradigms, and risk reduction

With improved outcomes following treatment of breast cancer, chronic toxicities including breast cancer related lymphedema (BCRL), gain increased significance with limited evidence-based guidelines present. This review attempts to summarize data addressing these concerns and provides recommendations based on currently published data. Substantial differences exist in rates of BCRL reported in the literature ranging from less than 5% to 65% based on locoregional therapy. Based on recent data, early diagnosis of BCRL appears critical and requires careful attention to patient risk factors and the use of newer diagnostic tools. Initial treatment with decongestive lymphatic therapy/compressive stockings can provide significant improvement in patient symptoms and volume reduction of edematous extremities. At this time, consensus recommendations for disease classification, diagnostic testing and treatment are still lacking. Awareness of the frequency of this toxicity is now important as more accurate clinical aids have become accessible to diagnose the condition at an earlier stage allowing timely intervention providing the opportunity for treatment strategies to be more effective.

Six-year experience routinely using moderate deep inspiration breath-hold for the reduction of cardiac dose in left-sided breast irradiation for patients with early-stage or locally advanced breast cancer

PURPOSE

Moderate deep inspiration breath-hold (mDIBH), using an Active Breathing Control device, has been used in our clinic since 2002 to reduce cardiac dose for patients receiving left-sided breast irradiation. We report our routine use of the mDIBH technique in clinically localized breast cancer, treated to the intact breast, reconstructed breast, or chest wall.

MATERIALS AND METHODS

Ninety-nine patients with left-sided breast cancer were evaluated for Active Breathing Control treatment, of which, 87 patients were treated with mDIBH. Plans for both the free-breathing (FB) and mDIBH computed tomography scans were evaluated. Dose-volume histograms (DVHs) were analyzed for the heart and ipsilateral lung, comparing results for mDIBH versus FB plans.

RESULTS

Eighty-seven patients were included for analysis. Of those, 66% received adjuvant chemotherapy with cardiotoxic agents. The mean dose for the whole breast was 47.6 Gy. There was a statistically significant decrease in all DVH parameters evaluated, favoring the delivery of mDIBH over FB plans. mDIBH plans significantly reduced cardiac mean dose (4.23 vs. 2.54 Gy; P<0.001), a relative reduction of 40%. In addition, there were significant reductions in all other heart parameters evaluated (ie, volume of heart treated, V30, V25, V20, V15, V10, and V5). mDIBH also significantly reduced lung dose, including a reduction of the left lung mean dose (9.08 vs. 7.86 Gy; P<0.001), a relative reduction of 13%, as well as significant reduction of all lung DVH parameters evaluated.

CONCLUSIONS

To date, this series represents the largest experience utilizing mDIBH to reduce cardiac irradiation during left-sided breast cancer treatment. Statistically significant reductions in all heart and lung DVH parameters were achieved with mDIBH over FB plans. mDIBH, for the treatment of left-sided breast cancer, is a proven technique for reducing cardiac dose that may lead to reduced cardiotoxicity and can be routinely integrated into the clinic.

Abstract P4-16-09: Dosimetric feasibility and acute toxicity in a prospective trial of ultra-short course accelerated partial breast irradiation (APBI) using a multi-lumen balloon brachytherapy device

Background: Shorter courses of APBI with novel fractionation schedules are being investigated; a large randomized trial from Europe has recently shown the safety and efficacy of a single-fraction adjuvant approach (with limited follow-up). We designed a prospective trial to identify and address the potential radiobiological and logistical limitations of single-fraction, intraoperative APBI.

Methods: We designed a single-arm, multi-institutional, prospective phase II trial that sequentially treats three cohorts of women (each n=30) with three progressively hypofractionated schedules. Eligible women were age ≥ 50 years with unifocal invasive or in situ tumors ≤ 3.0 cm, excised with negative margins, and with negative lymph nodes and positive hormone-receptors. Using a reference schedule of 60 Gy delivered in 2 Gy fractions, and assuming tumor parameters: a/b = 4 Gy; a = 0.27 Gy-1, and repopulation parameters of: Teff = 26 days; delay time = 0 days, the reference tumor BED is ∼ 86 Gy4. We began with a schedule of 4 fractions of 7 Gy delivered twice-daily using a Contura MLB multi-lumen device. We defined very conservative dosimetric criteria for acceptability: maximum skin and rib dose to not exceed 100% of prescription dose, and V150 and V200 to not exceed 40 cc and 10 cc, respectively. Subsequent schedules are 3 fractions of 8.25 Gy and 2 fractions of 10.25 Gy, both delivered over 2 days. The primary endpoint is to exclude a local failure rate exceeding 10% with the upper limit of a 95% confidence interval.

Results: A total of 30 patients have been enrolled at the 7 Gy × 4 fractions dose-level and followed for a minimum of 6 months. The median skin dose as a percent of prescription dose (PD) was 84% (40–100) and the median rib dose was 71% (16–119). 96% of the PTV_eval received a median of 95% of PD (range 85–103). The V150 (range 14–48cc) and V200 (range 0–29cc) criteria were met in all cases. One breast infection occurred and was treated; 2 cases of symptomatic fat necrosis and 2 cases of symptomatic seromas occurred. No acute toxicities greater than CTCAE grade 2 have been observed.

Conclusion: Short-course APBI is dosimetrically feasible using the Contura MLB and appears to be tolerable in terms of acute toxicities. Our approach is based on well-defined radiobiological parameters and allows for an abbreviated course of treatment that is guided by full pathological review and the ability to objectively achieve and validate acceptable dosimetric criteria in each case. We have opened enrollment to the next schedule of 8.25 Gy for three fractions.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-16-09.

Evaluation of current consensus statement recommendations for accelerated partial breast irradiation: a pooled analysis of William Beaumont Hospital and American Society of Breast Surgeon MammoSite Registry Trial Data

PURPOSE

To determine whether the American Society for Radiation Oncology (ASTRO) Consensus Statement (CS) recommendations for accelerated partial breast irradiation (APBI) are associated with significantly different outcomes in a pooled analysis from William Beaumont Hospital (WBH) and the American Society of Breast Surgeons (ASBrS) MammoSite® Registry Trial.

METHODS AND MATERIALS

APBI was used to treat 2127 cases of early-stage breast cancer (WBH, n=678; ASBrS, n=1449). Three forms of APBI were used at WBH (interstitial, n=221; balloon-based, n=255; or 3-dimensional conformal radiation therapy, n=206), whereas all Registry Trial patients received balloon-based brachytherapy. Patients were divided according to the ASTRO CS into suitable (n=661, 36.5%), cautionary (n=850, 46.9%), and unsuitable (n=302, 16.7%) categories. Tumor characteristics and clinical outcomes were analyzed according to CS group.

RESULTS

The median age was 65 years (range, 32-94 years), and the median tumor size was 10.0 mm (range, 0-45 mm). The median follow-up time was 60.6 months. The WBH cohort had more node-positive disease (6.9% vs 2.6%, P<.01) and cautionary patients (49.5% vs 41.8%, P=.06). The 5-year actuarial ipsilateral breast tumor recurrence (IBTR), regional nodal failure (RNF), and distant metastasis (DM) for the whole cohort were 2.8%, 0.6%, 1.6%. The rate of IBTR was not statistically higher between suitable (2.5%), cautionary (3.3%), or unsuitable (4.6%) patients (P=.20). The nonsignificant increase in IBTR for the cautionary and unsuitable categories was due to increased elsewhere failures and new primaries (P=.04), not tumor bed recurrence (P=.93).

CONCLUSIONS

Excellent outcomes after breast-conserving surgery and APBI were seen in our pooled analysis. The current ASTRO CS guidelines did not adequately differentiate patients at an increased risk of IBTR or tumor bed failure in this large patient cohort.

Long-term outcome from RTOG 9517: A phase I/II study of accelerated partial breast irradiation (APBI) with mulitcatheter brachytherapy (MCT) following lumpectomy for early-stage breast cancer

147

Background: Comparison of APBI to whole breast irradiation post lumpectomy for breast conservation is ongoing in phase III trials. However, APBI has gained acceptance in clinical practice despite relatively limited long-term data. RTOG 9517 studied MCT, one of the earliest methods of APBI, and can uniquely provide long-term cancer outcomes. Methods: Eligibility was stage I/II unifocal breast cancer <3cm, invasive non-lobular histology without EIC, negative surgical margins, and 0-3 positive axillary nodes; no extracapsular extension. The target volume was the lumpectomy cavity plus a 2 cm radial and 1 cm ant/post margin. Low Dose Rate (LDR), 45 Gy in 3.5-5 day, or High Dose Rate (HDR) 34 Gy in 10 BID fractions over 5 days was delivered. A rapid dosimetry review was done to assure dose delivery per protocol. Systemic therapy was per physician’s discretion. The primary endpoint was HDR and LDR MCT reproducibility. This analysis focuses on ipsilateral breast failure (IBF), contralateral breast cancer events (CBE), regional (RF) and distant failure (DF) (cumulative incidence) disease-free (DFS), relapse-free (RFS), and overall survival (OS), (Kaplan-Meier). Results: The median follow up is 12.1 years (yr). 100 patients were accrued from 1997-2000; 98 were evaluable; 65 HDR and 33 LDR MCT. Median age was 62; 88% had T1 tumors; 12% T2; 81% p N0, 19% pN1; 77% ER and/or PR +; 19% ER - and PR -; 33 % received adjuvant chemotherapy and 64% antiendocrine therapy. There have been 6 IBF for a 10 yr rate of 6.2%; 2 IBF were outside the APBI field. There were 5 total RF for a 10 yr rate of 5.2%, respectively. There have been 5 CBE for a 10 yr rate of 4.2%. Failure patterns were: 4 isolated IBF, 1 isolated RF, 8 DF only, 1 IBF+RF, 1 IBF+RF+DF, 1 RF+CBE, 1 RF+DF, 3 CBE, and 1 CBE+DF (21 total failures). Eleven patients have developed DF; 8 have died of breast cancer, 22 have died from other causes. The 10 yr DFS, RFS and OS are 69.8%, 71.9%, and 78.0%, respectively. Conclusions: This multi-institutional phase II trial studying MCT-APBI continues to report durable local regional cancer control rates with long term follow-up. Supported by NCI U10 grants CA21661 and CA37422.

Twenty-year outcomes after breast-conserving surgery and definitive radiotherapy for mammographically detected ductal carcinoma in situ

BACKGROUND

Management of mammographically detected ductal carcinoma in situ (DCIS) at a single institution was reviewed to determine long-term clinical outcomes after treatment with breast-conserving therapy (BCT).

METHODS

Data from all patient-cases with DCIS who received BCT between 1980 and 1993 were reviewed. Patient demographics and pathologic factors were analyzed for their effect on outcomes, including ipsilateral breast tumor recurrence (IBTR) and survival. BCT included breast-conserving surgery followed by external-beam radiotherapy to the whole breast, with 86 % of patients receiving a lumpectomy cavity boost. The median dose to the whole breast was 50 Gy and 60.4 Gy to the lumpectomy cavity.

RESULTS

A total of 129 cases were evaluated; the median follow-up was 19.3 years. Twenty-one patients developed an ipsilateral breast tumor recurrence (IBTR), 76.2 % of which were invasive (n = 16). Fourteen recurrences (66 %) were within the same breast quadrant (true recurrence), while an additional 7 cases developed an IBTR elsewhere in the breast. True recurrences were more prevalent in women <45 years of age (20 %/24 % vs. 5.1 %/8 %) at 10 and 20 years (p = 0.02). The 5-, 10-, 15-, and 20-year actuarial rates of IBTR for this cohort were 8.7, 10.4, 12.1, and 16.3 % (IBTR), while overall survival at 5, 10, and 20 years was 97.6, 96.8, and 96.8 %, respectively.

CONCLUSIONS

Mammographically detected DCIS remains a clinically distinct subset of noninvasive breast cancer. With 20 year follow-up, local control and overall survival are excellent after BCT.

P3-13-09: Impact of Estrogen Receptor Negativity on Clinical Outcomes Following Accelerated Partial Breast Irradiation

Purpose: To determine the impact of estrogen receptor (ER) negativity on clinical outcomes for patients treated with Accelerated Partial Breast Irradiation (APBI).

Materials/Methods(s): We evaluated 506 consecutive patients treated with interstitial brachytherapy (n= 199), balloon-based brachytherapy (n=203), and 3D-CRT (n=104). ER negative (ERN) status was assigned using the traditional definition of an ER nuclear IHC stain &lt; 10%, which corresponds to an Allred/NSABP staining score of &lt; 2. 63 patients (12.5%) were ER negative and 443 (87.5%) were ER positive (ERP). Patient demographics and clinical outcomes (IBTR, RNF, DM, DFS, CSS, OS) were analyzed for each group.

Results: The two groups had similar patient characteristics. Tumor sizes were slightly larger for the ERN group at 11.9mm vs. 10.7mm, although this was not statistically significant (p=0.14). No differences were seen in median age (63 vs. 64 years, p=0.36), rate of HER-2/neu overexpression (83% vs. 91%, p=0.11), or lymph node positivity (6% vs. 9%, p=0.55) between the ERN vs. ERP groups, respectively. There were an equal distribution of invasive ductal carcinoma (ERN n=55, 87%; ERP n=387, 87%) and DCIS (ERN n=8, 13%; ERP n=56, 13%) patients within each group. The use of chemotherapy (55% vs. 15%, p&lt;0.001) and nuclear grade (71% vs. 12%, p&lt;0.001) were higher in the ERN vs. ERP cohort. With a mean follow up of 6.1 years, the 5-year actuarial rates of ipsilateral breast tumor recurrence (IBTR), regional nodal failure (RNF), and distant metastasis (DM) for the entire cohort were 1.8%, 0.6%, and 3.2%. Although this was not statistically significant, ERN patients appear to have an increased rate of local failure than patients with ERP histology (4.0% vs. 1.5%, p=0.13). Rates of RNF and DM were, however, significantly higher for the ERN group (RNF: 4.9% ERN vs. 0% ERP, p&lt;0.001; DM: 12.1% ERN vs. 2.0% ERP, p&lt;0.001). Although there was no difference in overall survival at six years (86% vs. 90%, p=0.67), we observed a shorter disease-free survival (86.4% vs. 96.5%, p= 0.01) and cause-specific survival (90% vs. 98%, p=0.01) for the ERN vs. ERP groups.

Conclusion: The ER negative phenotype of early-stage breast cancer may have a decreased rate of locoregional control. We observed a higher rate of DM with reduced disease-free and cause-specific survival in ER negative cases, emphasizing the importance of systemic therapy and careful, long-term follow up for these patients. Prospective study of this histologic subtype with a larger cohort of patients is needed to substantiate these findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-13-09.

P3-13-01: Boost Radiation Therapy Not of Value in Reducing IBTR of Invasive or Noninvasive Breast Cancers for Patients with DCIS: Results from the NSABP B-24 Trial

Background: Whole breast irradiation therapy following lumpectomy for invasive breast cancer (IBC) or noninvasive breast cancer (DCIS) significantly reduces the risk of local recurrence. Boost radiation therapy to the tumor bed has been proven to additionally lower the risk of recurrence for IBC. The benefit of boost therapy in patients with DCIS is less certain. We carried out a review of the NSABP B-24 trial to assess the benefit of boost therapy.

Methods: After lumpectomy and radiation therapy, 1804 women with DCIS were randomly assigned to placebo (902) or tamoxifen (902). Whole breast irradiation therapy (50 Gy) was mandatory. Boost radiation therapy was optional, and boost status was known for 1,569 patients. Of these, 1392 patients (86.97%) were identified as having all data sufficient for multivariate analysis. Of these, 613 received boost therapy ranging from 1 Gy −20 Gy, with 81.5% receiving 10 Gy. Mean time of follow-up was 161 months.

Results: Patients who received boost radiation therapy were more likely to be younger (p=0.04), have positive margins (p=0.007), and be more likely to have comedo necrosis (p=0.03). Multivariate analysis identified only treatment (tamoxifen vs placebo) (HR=0.74, 95% CI=0.57−0.98, p=0.034), age (≥ 50 verses &lt; 50) (HR=0.47, 95% CI=0.36−0.61, p&lt;0.0001), and margin status (positive vs negative) (HR: 1.79, 95% CI= 1.31−2.43, p&lt;0.001) as significant predictors for ipsilateral breast tumor recurrence (IBTR). Boost had no significant effect on IBTR (HR=0.87, 95% CI=0.66−1.15, p=0.33). The lack of boost effect applied to both invasive (HR=0.86, 95% CI=0.58−1.27, p=0.44) and noninvasive IBTR (HR=0.89, 95% CI=0.60−1.33, p=0.56).

No interaction was seen between boost and treatment, age, margin status, or comedo necrosis.

Conclusion: In NSABP B-24, the addition of boost radiation therapy was not found to be of value in reducing IBTR of invasive or noninvasive breast cancers for patients with DCIS.

Supported by PHS grants NCI-U10-CA-69651, NCI-U10-CA-12027, and NCI P30-CA-14599 from the US NCI and AstraZeneca.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-13-01.

Factors associated with optimal long-term cosmetic results in patients treated with accelerated partial breast irradiation using balloon-based brachytherapy

PURPOSE

To evaluate factors associated with optimal cosmetic results at 72 months for early-stage breast cancer patients treated with Mammosite balloon-based accelerated partial breast irradiation (APBI).

METHODS AND MATERIALS

A total of 1,440 patients (1,449 cases) with early-stage breast cancer undergoing breast-conserving therapy were treated with balloon-based brachytherapy to deliver APBI (34 Gy in 3.4-Gy fractions). Cosmetic outcome was evaluated at each follow-up visit and dichotomized as excellent/good (E/G) or fair/poor (F/P). Follow-up was evaluated at 36 and 72 months to establish long-term cosmesis, stability of cosmesis, and factors associated with optimal results.

RESULTS

The percentage of evaluable patients with excellent/good (E/G) cosmetic results at 36 months and more than 72 months were 93.3% (n = 708/759) and 90.4% (n = 235/260). Factors associated with optimal cosmetic results at 72 months included: larger skin spacing (p = 0.04) and T1 tumors (p = 0.02). Using multiple regression analysis, the only factors predictive of worse cosmetic outcome at 72 months were smaller skin spacing (odds ratio [OR], 0.89; confidence interval [CI], 0.80-0.99) and tumors greater than 2 cm (OR, 4.96, CI, 1.53-16.07). In all, 227 patients had both a 36-month and a 72-month cosmetic evaluation. The number of patients with E/G cosmetic results decreased only slightly from 93.4% at 3 years to 90.8% (p = 0.13) at 6 years, respectively.

CONCLUSIONS

APBI delivered with balloon-based brachytherapy produced E/G cosmetic results in 90.4% of cases at 6 years. Larger tumors (T2) and smaller skin spacing were found to be the two most important independent predictors of cosmesis.

Accelerated partial breast irradiation

Whole breast irradiation (WBI) is the standard after breast conservation surgery. However, WBI in selected patients has been questioned. Accelerated partial breast irradiation (APBI) focuses treatment on the lumpectomy bed. Many modalities of delivering APBI have been developed: multicatheter interstitial brachytherapy, MammoSite balloon catheter, single insertion multicatheter devices, three-dimensional conformal external-beam radiation therapy and intraoperative techniques. Numerous studies of APBI have demonstrated excellent local control and cosmetic outcomes in early-stage breast cancer patients.

Monomorphic epithelial proliferations of the breast: a possible precursor lesion associated with ipsilateral breast failure after breast conserving therapy in patients with negative lumpectomy margins

BACKGROUND

It is generally believed that ipsilateral breast failures (IBFs) after breast-conserving therapy (BCT) develop from incompletely eradicated carcinoma. We previously suggested that monomorphic epithelial proliferations (MEPs) in the breast may be a pool of partially transformed clones from which breast carcinomas can arise and that radiation therapy (RT) may also reduce the risk of IBF by eradicating MEPs. We examined salvage mastectomy specimens in patients experiencing an IBF to define the relationship between MEPs and IBFs and an additional potential mechanism for IBF risk reduction by RT.

METHODS AND MATERIALS

The location, number, and distribution of radiation changes and MEPs relative to 51 IBFs were mapped in salvage mastectomy specimens from BCT patients with adequately excised, initial carcinomas (negative lumpectomy margins).

RESULTS

All 51 salvage mastectomies had diffuse, late radiation changes. None had active fibrocystic lesions. MEPs were predominantly located in the immediate vicinity of the IBFs. A mean of 39% of MEP cases were located within the IBF, 46% were located within 2 cm of the IBF, and 14% were 2-3 cm from the IBF.

CONCLUSIONS

MEPs appear to be a pool of partially transformed precursor lesions that can give rise to ductal carcinoma in situ and invasive carcinomas (CAs). Many IBFs may arise from MEPs that reemerge after RT. Radiation may also reduce IBF risk after BCT (including in patients with negative margins) by primarily eradicating MEPs.

Brachytherapy for Accelerated Partial-Breast Irradiation: A Rapidly Emerging Technology in Breast Cancer Care

Purpose

Brachytherapy is a method for delivering partial-breast irradiation after breast-conserving surgery (BCS). It is currently used in the community setting, although its efficacy has yet to be validated in prospective comparative trials. Frequency and factors influencing use have not been previously identified.

Methods

In a nationwide database of 6,882 Medicare beneficiaries (age ≥ 65 years) with private supplemental insurance (MarketScan Medicare Supplemental), claims codes identified patients treated with brachytherapy versus external-beam radiation after BCS for incident breast cancer (diagnosed from 2001 to 2006). Logistic regression modeled predictors of brachytherapy use.

Results

Frequency of brachytherapy use as an alternative to external-beam radiation after BCS increased over time (< 1% in 2001, 2% in 2002, 3% in 2003, 5% in 2004, 8% in 2005, 10% in 2006; P < .001). Increased use correlated temporally with US Food and Drug Administration approval and Medicare reimbursement of brachytherapy technology. Brachytherapy use was more likely in women with lymph node–negative disease (odds ratio [OR], 2.19; 95% CI, 1.17 to 4.11) or axillary surgery (OR, 1.74; 95% CI, 1.23 to 2.44). Brachytherapy use was also more likely in women with non–health maintenance organization insurance (OR, 1.81; 95% CI, 1.24 to 2.64) and in areas with higher median income (OR, 1.58; 95% CI, 1.05 to 2.38), lower density of radiation oncologists (OR, 1.78; 95% CI, 1.11 to 2.86), or higher density of surgeons (OR, 1.57; 95% CI, 1.07 to 2.31).

Conclusion

Despite ongoing questions regarding efficacy, breast brachytherapy was rapidly incorporated into the care of older, insured patients. In our era of frequently emerging novel technologies yet growing demands to optimize costs and outcomes, results provide insight into how clinical, policy, and socioeconomic factors influence new technology diffusion into conventional care.

Abstract P3-15-07: Late Toxicity and Patient Self-Assessment of Breast Appearance/Satisfaction on RTOG 0319: A Phase II Trial of Three Dimensional Conformal Radiation Therapy (3DCRT) Partial Breast Irradiation (PBI) Following Lumpectomy for Stage I and II Breast Cancer

Background:

Ongoing phase III trials are comparing accelerated PBI around the lumpectomy site to standard whole breast irradiation in early stage breast cancer. Recent studies have questioned the late toxicity from PBI delivered with 3DCRT. We evaluated late toxicity on patients (pts) treated on RTOG 0319.

Methods:52 pts with stage I-II breast cancer, ≥3 cm, negative margins, and &lt; 3 nodes positive were treated with 3DCRT PBI and received 38.5 Gy in 10 BID fractions over 5 days. Median follow-up was 5.3 years (min-max: 1.7-6.4 years). Five pts were deceased at 5 years. NCI CTCAE v3.0 was used to grade adverse events (AEs). At 3 years, 50 pts were available for AE reporting or late toxicity assessment.

Results: The treatment-related AEs were primarily grade 1 36.5%, 50% grade 2, and only 3 (5.8%) pts had grade 3 AEs. The grade 3 AEs in these pts were radiation dermatitis, skin fibrosis, telangectasia, and myositis. No baseline self-assessment of breast appearance is available. Patient self-assessment of breast appearance and satisfaction was available in 45 (87%) pts at 1 year and 36 (72%) at 3 years. At 1 year, 82% self reported excellent/good breast appearance and at 3 years, 64%. Pts who reported &lt; excellent/good breast appearance had significantly more grade ≥2 skin AEs (telangectasia, skin atrophy, hyperpigmentation, erythema, skin fibrosis, radiation dermatitis, and breast or nipple/areolar deformity). At 3 years, 31 of 36 pts were satisfied with their treatment, but all 36 would choose 3DCRT PBI again over standard breast RT. Treatment factors were evaluated to establish correlation with patient reported breast appearance. Preliminary observations suggest surgical bed volume, PTV volume, number of beams used, and possible use of bolus are associated with patient reported outcomes (PRO). Surgical factors impacting PRO were not collected.

Conclusions: The majority of pts were satisfied with their treatment results at 3 years and would all choose to have 3DCRT PBI again. With a median of 5.3 years, the rate of grade 3 AEs is low. Technical factors from this phase II trial were modified for the phase III NSABP B-39/RTOG 0413 trial, in which bolus is not allowed and both target volumes and required coverage were modified, increasing expectation of improved PRO. Supported by RTOG U10 CA21661, CCOP U10 CA37422 and ATC U24 CA 81647 NCI grants.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-15-07.

Rates of second malignancies after definitive local treatment for ductal carcinoma in situ of the breast

PURPOSE

We analyzed the risk of second malignancies developing in patients with ductal carcinoma in situ (DCIS) undergoing surgery and radiotherapy (S+RT) vs. surgery alone.

METHODS AND MATERIALS

The S+RT cohort consisted of 256 women treated with breast-conserving therapy at William Beaumont Hospital. The surgery alone cohort consisted of 2,788 women with DCIS in the regional Surveillance, Epidemiology, and End Results database treated during the same time period. A matched-pair analysis was performed in which each S+RT patient was randomly matched with 8 surgery alone patients (total of 2,048 patients). Matching criteria included age±2 years. The rates of second malignancies were analyzed overall and as contralateral breast vs. non-breast cancers and by organ system.

RESULTS

Median follow-up was 13.7 years for the S+RT cohort and 13.3 years for the surgery alone cohort. The overall 10-/15-year rates of second malignancies among the S+RT and surgery alone cohorts were 14.2%/24.2% and 16.4%/22.6%, respectively (p=0.668). The 15-year second contralateral breast cancer rate was 14.2% in the S+RT cohort and 10.3% in the surgery alone cohort (p=0.439). The 15-year risk of a second non-breast malignancy was 14.2% for the S+RT cohort and 13.4% for the surgery alone cohort (p=0.660). When analyzed by organ system, the 10- and 15-year rates of second malignancies did not differ between the S+RT and surgery alone cohorts for pulmonary, gastrointestinal, central nervous system, gynecologic, genitourinary, lymphoid, sarcomatoid, head and neck, or unknown primary tumors.

CONCLUSIONS

Compared with surgery alone, S+RT is not associated with an overall increased risk of second malignancies in women with DCIS.

Analysis of second malignancies after modern radiotherapy versus prostatectomy for localized prostate cancer

PURPOSE

To clarify the risk of developing second primary cancers (SPCs) after radiotherapy (RT) versus prostatectomy for localized prostate cancer (PCa) in the modern era.

METHODS

The RT cohort consisted of 2120 patients matched on a 1:1 basis with surgical patients according to age and follow-up time. RT techniques consisted of conventional or two-dimensional RT (2DRT, 36%), three-dimensional conformal RT and/or intensity modulated RT (3DCRT/IMRT, 29%), brachytherapy (BT, 16%), and a combination of 2DRT and BT (BT boost, 19%).

RESULTS

The overall SPC risk was not significantly different between the matched-pair (HR 1.14, 95% CI 0.94-1.39), but the risk became significant >5years or >10years after RT (HR 1.86, 95% CI 1.36-2.55; HR 4.94, 95% CI 2.18-11.2, respectively). The most significant sites of increased risk were bladder, lymphoproliferative, and sarcoma. Of the different RT techniques, only 2DRT was associated with a significantly higher risk (HR 1.76, 95% CI 1.32-2.35), but not BT boost (HR 0.83, 95% CI 0.50-1.38), 3DCRT/IMRT (HR 0.81, 95% CI 0.55-1.21), or BT (HR 0.53, 95% CI 0.28-1.01).

CONCLUSIONS

Radiation-related SPC risk varies depending on the RT technique and may be reduced by using BT, BT boost, or 3DCRT/IMRT.