Severity of Financial Toxicity for Patients Receiving Palliative Radiation Therapy

Introduction: Financial toxicity has negative implications for patient well-being and health outcomes. There is a gap in understanding financial toxicity for patients undergoing palliative radiotherapy (RT). Methods: A review of patients treated with palliative RT was conducted from January 2021 to December 2022. The FACIT-COST (COST) was measured (higher scores implying better financial well-being). Financial toxicity was graded according to previously suggested cutoffs: Grade 0 (score ≥26), Grade 1 (14-25), Grade 2 (1-13), and Grade 3 (0). FACIT-TS-G was used for treatment satisfaction, and EORTC QLQ-C30 was assessed for global health status and functional scales. Results: 53 patients were identified. Median COST was 25 (range 0-44), 49% had Grade 0 financial toxicity, 32% Grade 1, 15% Grade 2, and 4% Grade 3. Overall, cancer caused financial hardship among 45%. Higher COST was weakly associated with higher global health status/Quality of Life (QoL), physical functioning, role functioning, and cognitive functioning; moderately associated with higher social functioning; and strongly associated with improved emotional functioning. Higher income or Medicare or private coverage (rather than Medicaid) was associated with less financial toxicity, whereas an underrepresented minority background or a non-English language preference was associated with greater financial toxicity. A multivariate model found that higher area income (HR .80, P = .007) and higher cognitive functioning (HR .96, P = .01) were significantly associated with financial toxicity. Conclusions: Financial toxicity was seen in approximately half of patients receiving palliative RT. The highest risk groups were those with lower income and lower cognitive functioning. This study supports the measurement of financial toxicity by clinicians.

The Correlation Between Lymphocyte Nadir and Radiation Therapy for Soft Tissue Sarcoma: Defining Key Dosimetric Parameters and Outlining Clinical Significance

Purpose

The objectives of this study were to identify key dosimetric parameters associated with postradiation therapy lymphopenia and uncover any effect on clinical outcomes.

Methods and Materials

This was a retrospective review of 69 patients (between April 2010 and January 2023) who underwent radiation therapy (RT) as a part of curative intent for soft tissue sarcoma (STS) at a single academic institution. All patients with treatment plans available to review and measurable absolute lymphocyte count (ALC) nadir within a year after completion of RT were included.

Results

Median follow-up was 22 months after the start of RT. A decrease in lymphocyte count was noted as early as during treatment and persisted at least 3 months after the completion of RT. On multivariable linear regression, the strongest correlations with ALC nadir were mean body dose, body V10 Gy, mean bone dose, bone V10 Gy, and bone V20 Gy. Five-year overall survival was 60% and 5-year disease-free survival was 44%. Advanced T-stage, chemotherapy use, use of intensity-modulated RT, lower ALC nadir, and the development of grade ≥2 lymphopenia at nadir were associated with worse overall survival and disease-free survival.

Conclusions

Post-RT lymphopenia was associated with worse outcomes in STS. There were associations between higher body V10 Gy and bone V10 Gy and lower post-RT ALC nadir, despite the varying sites of STS presentation, which aligns with the well-known radiosensitivity of lymphocyte cell lines. These findings support efforts to reduce treatment-related hematopoietic toxicity as a way to improve oncologic outcomes. Additionally, this study supports the idea that the effect of radiation on lymphocyte progenitors in the bone marrow is more significant than that on circulating lymphocytes in treatments with limited involvement of the heart and lung.

Effect of a same day appointment initiative on racial disparities in access for radiation oncology

PURPOSE

We present our single-institution experience with the development of a same day access scheduling initiative for an outpatient radiation oncology unit, focusing on its potential influence on ameliorating racial disparities.

METHODS AND MATERIALS

From March 2021 to August 2022, a pilot initiative was conducted such that all new patients referred to a tertiary care-based radiation oncology department were offered the ability to be seen as a same day consultation. The timespan of this analysis was categorized into 2 distinct successive periods over 36 months-a 18-month pre-initiative period (September 2019 to February 2021) and another subsequent one (March 2021 to August 2022). Descriptive statistics were used to study the impact of this initiative on access-related benchmarks.

RESULTS

A total of 2897 patients were referred. Among the 2107 patients scheduled, three hundred and sixteen (15 %) opted for same day appointments. Black, Latino, and Asian patients were significantly more likely to use the same day access initiative versus Caucasian patients (p = 0.01). The same day access initiative increased the proportion of patients seen within 5 days from referral from 8 % to 34 % for Blacks, 12-57 % for Latinos, and 18-67 % for Asians, compared to 39-55 % for Caucasians (p < 0.001). The no-show rate was reduced from 20 % to 7 % and 14-5 %, for Black and Latino patients, respectively (p < 0.001).

CONCLUSIONS

The implementation of a same day access initiative narrowed disparities with respect to access-related benchmarks.

Utilization of cancer survivorship services during the COVID-19 pandemic in a tertiary referral center

BACKGROUND

All Commission on Cancer-accredited comprehensive cancer centers offer survivorship programs (SPs) to women upon completion of treatment. These SPs can include clinical and non-clinical programming such as physical rehabilitation, emotional and psychosocial support, nutrition, and exercise programming. Concern about the availability and access to these programs during the COVID-19 pandemic has been described in recent literature. We sought to identify the impact of the COVID-19 pandemic on participation in these supportive services for breast cancer patients within a single institution.

METHODS

The Ohio State University tertiary care center offers clinical and non-clinical breast cancer support services. Descriptive statistics were utilized to summarize referral and patient participation data from January 2019 through July 2021. Data from calendar year 2019 was used as a normative comparison for pre-COVID-19. In-person and telehealth use was tracked longitudinally.

RESULTS

During the lockdown due to the COVID-19 pandemic (March through May 2020), provider referrals to SPs declined by 10%, while the overall total for the calendar year modestly increased from 1195 in 2019 to 1210 in 2020, representing a 1.3% increase. Psycho-oncology referrals increased from 280 to 318 (13.5%). The most significant change of participation rates in non-clinical SPs during the pandemic was utilization of exercise content, which increased by 220% from 2019 to 2020. The total proportion of breast cancer participants choosing an exercise program increased from 16.8% in 2019 to 42.2% in 2021, making it the most selected program area overall. Previously, nutrition was the most selected program area as it comprised 42.5% of overall utilization in 2019.

CONCLUSION

The pandemic's potential to place barriers to participation in SPs is a legitimate concern. We found a modest decline in provider referrals to clinical services during the lockdown period, while patient-directed participation increased with more survivors engaging in exercise-based programs. Transitioning to virtual platforms served to maintain access for patients.

IMPLICATIONS FOR CANCER SURVIVORS

As we grapple with the COVID-19 pandemic, patients with cancer deserve increased attention due to the expected stressors associated with the diagnosis. Those in the survivorship stage utilize services for psychosocial support, and the observed increase in utilization of SPs suggests an elevated need for connectivity. To meet this need, telehealth platforms have been expanded to allow for continued participation. It remains to be seen whether this will be sustained post-COVID-19 or whether reduced human contact will create new needs for programming.

Pre- and Post-Treatment Patient-Reported Financial Toxicity in Head and Neck Cancer: Identifying Influential Factors and Clinical Significance

PURPOSE/OBJECTIVE(S)

Head and neck cancer patients are at high-risk for financial stress due to the often complex, time-consuming, and expensive treatments that can impact physical function and quality of life. It is important to identify factors that affect financial toxicity early on in treatment and to help mitigate their effects. The goals of this study are to assess patient-reported financial toxicity prior to and after completion of radiation therapy (RT) and to uncover any interactions with socioeconomic factors, quality of life, treatment satisfaction, and treatment adherence.

MATERIALS/METHODS

A total of 80 patients who were evaluated for RT to the head and neck region between July 2021 and December 2022 and had completed surveys prior to the initiation of RT were included. Surveys included the FACIT-COST and FACIT-TS-G. Patient clinical information and demographics were collected. Linear regression was used to evaluate categorical variables and Pearson correlation was used to evaluate continuous variables and their associations with COST.

RESULTS

The median pre-RT COST was 29.5 (range 4-44) with lower scores indicating worse financial toxicity. The majority of patients were white (69%), non-Hispanic (75%), and English-speaking (75%). 65% had Medicare, 14% had Medicaid, and 21% had other insurance. 60 of 80 (75%) patients ultimately underwent RT at our institution. 34 (57%) missed at least one day of scheduled RT fractions and 11 (14%) patients had G-tubes placed. Lower COST was associated with decreased age, thyroid primary disease, advanced stage, metastatic disease, Medicaid insurance, Hispanic ethnicity, unemployment, and G-tube placement. Higher COST was associated with cutaneous primary disease and ability to speak English, while Medicare insurance trended toward significance. 18 of 80 patients (23%) completed follow-up surveys post-RT and 9 reported a decrease in COST. At baseline, the standard deviation of the COST was 10.6. Effect size was defined as the number of standard deviation change. Mean decrease in COST was 9.4 (effect size of 89%). Mean FACT-TS-G was lower, indicating decreased treatment satisfaction, for these patients as compared to those that had the same or increased COST compared to baseline, (17.4 vs. 22.7, p < 0.01). There were more missed RT days, 4 vs. 1, and G-tube placements, 2 vs. 0, in those with decreased COST as well.

CONCLUSION

Worse baseline financial toxicity was associated with younger age, advanced stage, metastatic disease, Medicaid insurance, unemployment, and G-tube placement. Those that reported worsened financial toxicity after RT reported worse treatment satisfaction and had more missed RT days and G-tube placements. These findings support work to better understand financial toxicity as it may predict those at higher risk of missing treatments, particularly crucial considering prolonged RT duration is linked to poorer outcomes. Future efforts will focus on automating early referrals to case managers and social work services for these patients.

The Axillary Lateral Vessel Thoracic Junction Is Not an Organ at Risk for Breast Cancer-Related Lymphedema

PURPOSE

Breast cancer-related lymphedema (BCRL) is a treatment complication that significantly reduces patient quality of life. Regional nodal irradiation (RNI) may increase the risk of BCRL. Recently, a region of the axilla known as the axillary-lateral thoracic vessel juncture (ALTJ) was identified as a potential organ at risk (OAR). Here, we set out to validate whether radiation dose to the ALTJ is associated with BCRL.

METHODS AND MATERIALS

We identified patients with stage II-III breast cancer treated with adjuvant RNI from 2013 to 2018, excluding those with BCRL preradiation. We defined BCRL as difference in arm circumference between the ipsilateral and contralateral limb >2.5 cm at any 1 encounter or ≥2 cm on ≥2 visits. All patients suspected of having BCRL at routine follow-up visits were referred to physical therapy for confirmation. The ALTJ was retrospectively contoured and dose metrics were collected. Cox proportional hazards regression models were used to test the association between clinical and dosimetric parameters with the development of BCRL.

RESULTS

The study population included 378 patients with a median age of 53 years, median body mass index of 28.4 kg/m2, and median of 18 axillary nodes removed; 71% underwent mastectomy. Median follow-up was 70 months (interquartile range, 55-89.7 months). BCRL developed in 101 patients at a median of 18.9 months (interquartile range, 9.9-32.4 months), with a corresponding 5-year cumulative incidence BCRL of 25.8%. On multivariate analysis, none of the ALTJ metrics were associated with BCRL risk. Only increasing age, increasing body mass index, and increasing number of nodes were associated with a higher risk of developing BCRL. The 6-year locoregional recurrence rate was 3.2%, the axillary recurrence rate was 1.7%, and the isolated axillary recurrence rate was 0%.

CONCLUSIONS

The ALTJ is not validated as a critical OAR for reducing BCRL risk. Until such an OAR is discovered, the axillary PTV should not be modified or dose reduced in efforts to reduce BCRL.

Severity of Financial Toxicity for Patients Receiving Palliative Radiation Therapy

PURPOSE/OBJECTIVE(S)

Patients receiving palliative radiotherapy (RT) are often at their most vulnerable state, but the impact of financial toxicity on their health and quality of life (QOL) is not well-described. We set out to determine the degree of financial toxicity in a population undergoing palliative RT.

MATERIALS/METHODS

A review of patients referred for palliative RT at our site was conducted. Financial toxicity was determined with COST-FACIT, and previously suggested grading cutoffs were used. Additional patient-reported outcome (PRO) instruments included the EORTC overall health and quality of life questions and the FACIT-TS-G (treatment satisfaction). Multiple imputations by chained equations using predictive mean matching were used for incomplete responses. Spearman's rank correlation coefficient, Kruskal-Wallis testing, and linear regressions were used to measure associations.

RESULTS

A total of 53 patients were identified who had completed PRO surveys between May 2021 and December 2022. Median COST was 25 (range 0-44), with lower scores indicating greater financial toxicity. 49% reported grade 0 financial toxicity (COST ≥26), 32% had grade 1 financial toxicity (COST 14-25), 19% had grade 2 financial toxicity (COST 1-13), and 6% had grade 3 financial toxicity (COST = 0). Overall, cancer caused financial hardship among 45%. Higher COST was moderately associated with higher overall health (rho = 0.36, p = 0.02) and weakly associated with higher QOL (rho = 0.28, p = 0.07). From a demographic standpoint, median area family income from census tract data was $98,598 (range $32,303-$190,833), and higher income was associated with higher COST (rho = 0.47, p<0.001). Having Medicare (beta = 13.8, p = 0.003) or private (beta = 13.5, p = 0.001) coverage (rather than Medicaid) were associated with less financial toxicity, whereas having an underrepresented minority background (beta = -13.2, p<0.001), or having a non-English language preference (rho = 0.40, p = 0.003) were associated with greater financial toxicity. Median time from diagnosis was 12.9 mo, and 40% of patients had ≥2 prior systemic therapies. The median RT dose was 25 Gy (range 4-45 Gy). The most common irradiated sites included spine (24%), non-spine bones (21%), brain (18%), and lung/mediastinum (18%). COST was not associated with number of prior systemic therapies (p = 0.31), RT dose (p = 0.83), RT technique (p = 0.86), or treatment satisfaction (p = 0.34). Median follow up was 8.0 months, and median 6-month survival was 83% (95% CI 73%-95%). Inferior OS was associated with more prior systemic therapies (HR 3.43, p = 0.03), but not with COST (HR 1.01, p = 0.67).

CONCLUSION

Financial toxicity was seen in approximately half of patients receiving palliative RT. Patient-reported overall health, Medicaid coverage, and area income correlated well with financial toxicity, but the investigated clinical characteristics did not. This supports the hypothesis that financial toxicity is common and a unique factor that should be measured in cancer patients.

Locoregional Treatment for Early-Stage Breast Cancer: Current Status and Future Perspectives

BACKGROUND

The locoregional recurrence of breast cancer has been reduced due to the multidisciplinary approach of breast surgery, systemic therapy and radiation. Early detection and better surgical techniques contribute to an improvement in breast cancer outcomes.

PURPOSE OF REVIEW

The purpose of this review is to have an overview and summary of the current evidence behind the current approaches to the locoregional treatment of breast cancer and to discuss its future direction.

SUMMARY

With improved surgical techniques and the use of a more effective neoadjuvant systemic therapy, including checkpoint inhibitors and dual HER2-directed therapies that lead to a higher frequency of pathologic complete responses and advances in adjuvant radiation therapy, breast cancer patients are experiencing better locoregional control and reduced local and systemic recurrence. De-escalation in surgery has not only improved the quality of life in the majority of breast cancer patients, but also maintained the low risk of recurrence. There are ongoing clinical trials to optimize radiation therapy in breast cancer. More modern radiation technologies are evolving to improve the patient outcome and reduce radiation toxicities.

Abstract P3-19-03: Preliminary results of a feasibility study assessing radiation response with MRI/CT directed preoperative accelerated partial breast irradiation in the prone position for hormone responsive early stage breast cancer

BACKGROUND: Accelerated partial breast irradiation (APBI) has emerged as an alternative to whole breast irradiation (WBI) following lumpectomy for select patients. However, the challenges to post-operative APBI include targeting inaccuracy and the inability to measure tumor response to radiation. We hypothesized that preoperative APBI (pAPBI) could reliably target the tumor using MRI-guidance that is acquired prone in combination with our established prone breast radiation delivery. We developed methodology for prone CT simulation to establish radiation position, MRI acquisition in treatment position, registration of MRI-CT data for treatment planning, and treatment delivery with daily cone-beam CT using the same immobilization platform. This study aimed to assess the reproducibility, toxicity and local control associated with MRI/CT-directed prone pAPBI. METHODS: This was a prospective, single arm study enrolling patients &gt;50 yo with clinical (c) Stage IA ER+/PR+/HER2- breast cancer intending lumpectomy. Axillary US and MRI imaging to confirm clinical node negative disease was required. A planning CT in the prone position was followed by MRI using the same prone immobilization platform. Rigid registration of MRI-CT data was used for radiation planning. pAPBI of 3850 cGy was delivered in 10 fractions BID with the same prone immobilization technique. Another MRI was obtained 4 weeks post-APBI to assess tumor response. The intensity, kinetics and volume of the lesion on MRI was quantitatively assessed and an experienced reader evaluated MRI volume and kinetic changes in the tumor post-APBI. Lumpectomy was performed 4-6 weeks after APBI. Simon 2 stage design required assessment after accrual of 19 patients for assessment of feasibility. RESULTS: Nineteen cStage IA ER+/PR+/HER2- breast cancer patients with a median age of 65 (range 51-78) were enrolled on the study, completed APBI, lumpectomy, and adjuvant AI. Median follow up was 3.4 years. Mean clinical tumor size was 1.1 cm ± 0.4 and mean path tumor size was 0.94 cm ± 0.6. There was complete pathologic response in 10.5% (n=2) and an additional 36.8% (n=7) were downstaged from clinical stage (measured by mammogram/US) to pathologic stage, resulting in a total response of 47.4% (n=9). Six (31.6%) patients had stable disease after APBI. Four (21.0%) were upstaged from clinical stage to pathological stage. Tumor response detected by MRI significantly correlated with tumor response based on clinical to pathologic stage (p=0.03). Cosmesis was rated as excellent/good in 89.5% (n=17) patients post-APBI. Cosmesis worsened to fair in 2 patients post-APBI, one of which required adjuvant WBI after focal triple negative breast cancer was detected on pathology. Three patients had positive macrometastatic lymph nodes on final pathology despite clinically negative nodes on imaging. One in-breast recurrence outside the RT field was detected by MRI at 14 months, resulting in a locoregional recurrence rate of 5.4% at 3.4 years. Another patient developed metastases at 20 months. CONCLUSIONS: Using the same prone platform, all patients successfully underwent CT simulation, MRI acquisition, and completed pAPBI. Nearly half of enrolled patients had a measurable tumor response to pAPBI based on MRI and pathologic response, confirming the accuracy and reproducibility of defining tumor targets with our MRI/CT-directed pAPBI approach. While this methodology for prone pAPBI resulted in good cosmesis and local control and remains a promising approach for select patients, the challenge of excluding patients with subclinical lymph node positive disease remains. Correlative studies will determine whether Ki-67 and OncotypeDx pre- and post-APBI can help predict response to pAPBI.

Citation Format: Sasha Beyer, Tamara Smith, Ashley Sekhon, Jose Bazan, Sachin Jhawar, Erin Healy, Lai Wei, Vedat Yildiz, Mohamed Mohamed, Michael Knopp, Julia White. Preliminary results of a feasibility study assessing radiation response with MRI/CT directed preoperative accelerated partial breast irradiation in the prone position for hormone responsive early stage breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-03.

Abstract P3-19-17: Radiation of the low axilla in the prone position

Background: Whole breast irradiation (WBI) after a positive sentinel lymph node biopsy (SNB) is recommended to be treated in the supine position to facilitate inclusion of the low axilla with “high tangents” when regional nodal irradiation is not planned. Treatment in the prone position has several advantages over supine positioning including minimizing heart and lung doses for many and decreased skin toxicity for larger breasted women. We hypothesized that, using three dimensional conformal radiation therapy (3DCRT), the low axilla can be safely and adequately treated in the prone position with minimal toxicity and good outcomes. Methods: We identified patients who underwent post lumpectomy whole breast and low axilla irradiation in the prone position using 3DCRT from 2014 to 2020. Standard 3DCRT treatment planning included delineation of surgical cavity, breast and low axillary clinical target volumes (CTV) with 5 mm expansion to planning target volumes (PTV). The “low axilla” CTV was generally defined as the level I axilla according to the RTOG Breast Cancer Atlas. Dosimetric data for both targets and organs at risk (OARs) was extracted from approved treatment plans’ dose-volume histograms (DVHs). Toxicity and cancer outcomes were collected from the electronic medical records. Descriptive statistical analysis was performed. Results: Seventy patients were identified. Median age was 61 years (range 34-87), median body mass index (BMI) was 30.4 kg/m2 (range 22.1-49.1), and 88.6% (N=62) had hormone sensitive, HER2 negative breast cancer. The median tumor size was 1.35 cm (range 0.07-4.5cm). For 56 patients (80.0%), a SNB was done with median of 2 (range 1-7) sentinel nodes removed - 19 (34%) with macro-metastasis (median size 4 mm, range 2.2-13mm), 21 (37.5%) with micrometastasis, and 16 (28.6%) with isolated tumor cells. Three patients had an additional node with isolated tumor cells. Thirteen (18.6%) were Nx (no nodal evaluation) and 1 had an unsuccessful SLNB with no lymph nodes obtained. Hypofractionation was used in 97.1% (N=68): 4256 cGy in 16 fractions (N=44, 62.8%) or 4000 cGy in 15 fractions (N=24, 34.3%). All targets were covered adequately. The median V95/V90 of the PTVbreast_eval, PTVlump_eval, and PTVAx were 96%/98.3% (range 76.2/91.9% - 99.6/101.4%), 100.1%/101.2% (range 87.6/94.9%-102.8/103.3%), and 95.3%/97.5% (range 82.4/91.6%-100.4/101.7%) respectively. The mean heart dose for all patients was 83.5 cGy; 82.7 cGy for right-sided tumors and 83.8 cGy for left-sided tumors. The median V16 of the ipsilateral lung was 4.25% (range 0.2 - 11.3%). Overall, toxicity was low with no grade 3 or higher events. For acute toxicity, most patients (N=54, 77.1%) reported grade 1 fatigue and had either grade 1 (N=52, 74.2%) or grade 2 (N=15, 21.4%) dermatitis. For late toxicity, 14 patients (20%) were referred to physical therapy after radiation, 7 (10%) for range of motion, 5 (7%) for arm lymphedema evaluation and 4 (6%) for other reasons. With a median follow-up of 18.5 months (range 0-63 months), 1 patient recurred both locally and regionally (1.4%) and one other patient recurred distantly. Conclusions: Patients with a positive SNB or are Nx who are recommended to have post-lumpectomy whole breast and low axilla irradiation can be safely and adequately treated in the prone position using 3DCRT with minimal toxicity and good outcomes.

Citation Format: Victoria Doss, Erin Healy, Sasha Beyer, Sachin R. Jhawar, Jose G. Bazan, Julia White. Radiation of the low axilla in the prone position [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-17.

Abstract P3-19-08: Breast cancer related lymphedema in patients undergoing RNI: Is the axillary lateral vessel thoracic junction an organ-at-risk?

Background: Breast-cancer related lymphedema (BCRL) is a devastating treatment complication driven by the extent of axillary surgery (axillary lymph node dissection [ALND] versus sentinel lymph node biopsy [SLNB]). Regional nodal irradiation (RNI) may increase the risk of BCRL by up to 5%. Recently, investigators identified a region of the axilla known as the axillary-lateral thoracic vessel juncture (ALTJ) as a potential organ-at-risk (OAR) demonstrating that increasing radiation dose to the ALTJ was associated with a higher risk of BCRL. Here, we set to validate whether radiation dose to the ALTJ is associated with BCRL. Materials/Methods: We identified patients with stage II-III breast cancer treated with adjuvant RNI after M or L from 2013-2018 excluding those with BCRL pre-radiation. RNI treatment planning included delineation of clinical target volumes (CTVs): breast or chest wall and regional lymph nodes per the RTOG Breast Cancer Atlas. The CTVs were expanded by 5mm to create the planning target volume (PTV). Dose delivered was 50 Gy/25 fractions with goal of 47.5 Gy (95%) to 95% of each PTV. We defined BCRL as difference in arm circumference between the ipsilateral and contralateral limb &gt;2.5 cm at any 1 visit or ≥2 cm on at least 2 visits. All patients suspected of having BCRL at routine follow-up visits were evaluated by physical therapy. The ALTJ was retrospectively contoured and the following metrics collected: maximum/minimum/mean dose; V10Gy-V50Gy. Follow-up time was defined as the time from surgery to the development of BCRL or last follow-up. Cox proportional hazards regression models were used to test the association between clinical and dosimetric parameters with the development of BCRL. All variables with p&lt;0.10 on univariate analysis were entered in the final multivariate model (p&lt;0.05 considered statistically significant). Results: Population includes 378 patients with median age 53 years (interquartile range [IQR], 45-61 years), median body mass index (BMI) 28.4 kg/m2 (IQR, 24.3-33.4 kg/m2), 60% HR+/HER2-, 89% chemotherapy, 53% stage III, 71% underwent M, and 82% underwent ALND with median of 18 nodes removed (IQR, 11-25) and median of 2+ nodes (IQR, 1-5). Median follow-up time was 54.5 months (IQR, 40.3-72.2 months). The ALTJ and axilla PTV overlapped in 91% of the patients. BCRL developed in 97 patients (25.7%) at a median of 18.9 months (IQR, 9.9-30.6 months). The 4-year cumulative incidence of BCRL was 23.5% (26.6% ALND vs. 8.7% SLNB, p=0.002). On univariate analysis, increasing age (HR=1.02, p=.039), increasing BMI (HR=1.04, p=0.002), increasing number of nodes removed (HR=1.04, p&lt;0.0001), and use of IMRT vs. 3DCRT (HR=1.50, p=0.041) were all significantly associated with developing BCRL while increasing size of the axilla PTV (HR=0.96, p=0.047) was associated with a lower risk. None of the ALTJ metrics were associated with developing BCRL. Increasing ALTJ V45 was marginally associated with a lower risk of BCRL (HR=0.96, p=0.091). On multivariate analysis, increasing age (HR=1.02, p=0.021), increasing BMI (HR=1.04, p=0.004), and increasing number of nodes removed (HR=1.03, p=0.001) were associated with a higher risk of developing BCRL while use of IMRT (HR=1.24, p=0.338), size of the axilla PTV (HR=0.96, p=0.110) and ALTJ V45 (HR=0.99, p=0.708) were not. There were 10 local-regional recurrence (LRR) events as a first failure, 8 of which occurred with simultaneous distant metastases (DM). Of these LRRs, 5 included an axillary nodal component (all with DM) resulting in a 2.6% 4-year LRR rate (1.4% axillary recurrence rate). Conclusion: In this analysis, ALTJ is not validated as a critical OAR for reducing BCRL risk. Until such an OAR is discovered, the axillary PTV should not be modified or dose reduced in efforts to reduce BCRL given the low LRR and inability to validate ALTJ as an OAR.

Citation Format: Erin Healy, Sachin Jhawar, Sasha Beyer, Julia R White, Jose G Bazan. Breast cancer related lymphedema in patients undergoing RNI: Is the axillary lateral vessel thoracic junction an organ-at-risk? [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-08.

Abstract P3-19-09: Impact of intraoperative radiation therapy and external beam radiation therapy on non-breast cancer mortality in early-stage breast cancer

Purpose: The TARGIT-A trial of kilovoltage intraoperative radiation therapy (IORT) versus external beam radiation therapy (EBRT) demonstrated a significant reduction in non-breast cancer mortality (nBCM) in women that received IORT, largely attributed to an increase in cardiac mortality in patients that received EBRT. Further, If EBRT does result in excess nBCM due to cardiac or other causes, then treatment with lumpectomy (Lump) alone or mastectomy (Mast) alone should result in lower rates of nBCM rates compared to Lump+EBRT. Our primary objective was to determine whether Lump+EBRT results in increased nBCM compared to Lump+IORT in women with early-stage breast cancer (BC) with a hypothesis that the two approaches should result in equivalent nBCM. We also tested the hypotheses that Lump+EBRT should have the same rates of nBCM as Lump alone or Mast alone. Materials/Methods: We used the Surveillance Epidemiology and End Results (SEER) database to identify women with early-stage BC treated with Lump alone, Lump+EBRT, Lump+IORT, or Mast alone from 2000-2016. SEER does not distinguish between kilovoltage IORT and electron IORT. We included patients with characteristics similar to the TARGIT-A study: age≥45 years; ductal carcinoma in situ (DCIS) or T1; lymph-node negative. We excluded patients that: received chemotherapy; received postmastectomy radiation therapy; had unknown cause of death; and had ≤1 month of follow-up. The primary endpoint was nBCM which is captured in the SEER database (patients were censored if they were alive or dead due to cancer at last follow-up). Cox-proportional hazards multivariate regression models were used to compare nBCM between Lump+EBRT and Lump+IORT adjusting for confounders that were statistically significant on univariate analysis. We secondarily compared nBCM in the Lump+EBRT vs. Lump population and Lump+EBRT vs. Mast population. Results: We identified 219,470 women that met the inclusion criteria: 121,776 Lump+EBRT; 1,735 Lump+IORT; 41,900 Lump; 54,059 Mast. Median follow-up time was 61 months for the entire cohort (IQR, 30-99 months) but was shorter for Lump+IORT patients (29 months) compared to the other groups (63 months Lump+EBRT; 62 months Mast; 57 months Lump). There were a total of 16,640 nBCM events: 6,210 Lump+EBRT; 5,708 Lump; 4,704 Mast; 18 Lump+IORT. The 5-year cumulative incidence of nBCM was 3.1% for Lump+EBRT vs. 1.6% for Lump+IORT (p=0.034). After adjustment for potential confounders (age, tumor location, marital status, race/ethnicity, DCIS vs. invasive, tumor grade, hormone receptor status, and receipt of axillary surgery), patients treated with Lump+IORT had a 38% relative reduction in the risk of nBCM compared to those treated with Lump+EBRT (HR=0.62, 95% CI 0.39-0.99, p=0.045). Other factors associated with increased nBCM included older age, divorced/single/widowed status (vs. married), Black race, high tumor grade, receipt of axillary lymph node dissection (vs. sentinel lymph node biopsy), no axillary surgery (vs. sentinel node biopsy), and ER-/PR- disease (vs. ER+ or PR+). In contrast, patients treated with Lulmp+EBRT had lower nBCM compared to those that received Lump alone (adjusted HR=0.55, 95% CI 0.53-0.57, p&lt;0.0001) and compared to those that received Mast alone (adjusted HR=0.59, 95% CI 0.56-0.61, p&lt;0.0001). Conclusion: In summary, contrary to our hypothesis, we found that Lump+IORT was associated with lower nBCM compared to Lump+EBRT possibly reflecting underlying selection bias. However, Lump+EBRT was not associated with an increased nBCM relative to patients treated with Lump alone or Mast alone. This suggests that the underlying mechanism for the reduced nBCM seen in patients treated with IORT in the TARGIT-A trial and this SEER analysis is not due to the potentially harmful effects of EBRT.

Citation Format: Jose G Bazan, Jay Fisher, Sachin Jhawar, Erin Healy, Sasha Beyer, Julia R. White. Impact of intraoperative radiation therapy and external beam radiation therapy on non-breast cancer mortality in early-stage breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-09.

Abstract P3-19-02: Should deep inspiration breath hold scans be standardly acquired for right-sided breast/chestwall and regional nodal irradiation?

Background: Adjuvant regional nodal irradiation (RNI) after breast conserving surgery or mastectomy is supported by clinical trials for patients with node-positive breast cancer. RNI results in increased radiation dose to organs-at-risk (OARs) such as the heart and lungs. While regular acquisition of both free breathing (FB) and deep inspiration breath hold (DIBH) scans has been widely adopted for left-sided breast cancers (LBCs) as a cardiac-sparing technique, DIBH scans are not routinely acquired for right-sided breast cancers (RBCs). Therefore, when OAR constraints cannot be met with 3D conformal radiation therapy (3DCRT) planning on the FB scan, the only option is intensity modulated radiation therapy (IMRT), with its inherent increased cost, resource utilization, and requirement for insurance authorization. Given these challenges, we have regularly acquired FB and DIBH scans for right-sided RNI since 2018. We hypothesized that acquisition of DIBH scans would result in a reduced need for IMRT and reduced dose to OARs. Methods: We retrospectively identified patients who were treated with right-sided RNI who had both FB and DIBH scans. All patients had target volumes (breast or chest wall and regional lymph nodes [undissected axillary, supraclavicular, and internal mammary nodes]) prospectively contoured on the FBCT scan based upon the RTOG Breast Atlas. This initiated a treatment planning algorithm that began with creating a FB 3DCRT plan and changed to DIBH 3DCRT then FB IMRT when OAR constraints could not be met while maintaining acceptable planning target volume (PTV) coverage. For patients who did not have contours available on the DIBH scan, the treating physician retrospectively completed the PTV contours. For each patient, three total plans were created for comparison using our institutional target coverage and OAR metrics: FB 3DCRT, FB IMRT, and DIBH 3DCRT. We compared PTV coverage and doses to multiple OARs including the contralateral breast, esophagus, heart, lungs (left, right, total lung dose), and liver. PTV coverage and OAR doses were evaluated by a one-way ANOVA followed by Bonferroni comparison. A p &lt; 0.05 was considered statistically significant.Results: We identified 38 patients in whom FB and DIBH scans were acquired. Only 32% (N=12) were treated with the standard FB 3DCRT. Of the remaining 26 patients 73% (N=19) were treated DIBH 3DCRT, and only 27% (N=7) were treated with FB IMRT, resulting in a FB IMRT rate of 18% overall. Without DIBH scans, 68% (N=19) would have advanced to FB IMRT. Dosimetric comparison across these 38 patients (N=114 plans) demonstrated that DIBH 3DCRT had at least equivalent OAR metrics as compared to FB 3DCRT, with significant improvement in max heart dose (9.6 Gy vs. 14.9 Gy; p = 0.034), right lung V20 (32.1% vs 37.8%; p &lt; 0.01), mean total lung dose (8.9 Gy vs. 10.5 Gy; p &lt; 0.01), and mean liver dose (1.8 Gy vs. 4.0 Gy; p &lt; 0.01). FB IMRT plans resulting in significantly lower right lung V20 (26.3% FB IMRT vs. 37.8% FB 3DCRT vs. 32.1% DIBH 3DCRT), but resulted in higher dose to the heart and contralateral breast: mean heart dose (2.2 Gy FB IMRT vs. 1.0 Gy FB 3DCRT vs. 0.9 Gy DIBH 3DCRT; p &lt; 0.01), maximum heart dose (16.4 Gy FB IMRT vs. 14.9 Gy FB 3DCRT vs. 9.6 Gy DIBH 3DCRT; p &lt; 0.01) and contralateral breast D5% (5.0 Gy FB IMRT vs. 2.9 Gy FB 3DCRT vs. 3.0 Gy DIBH 3DCRT; p &lt; 0.01).Conclusions: We found that acquiring DIBH scans for RBC patients receiving RNI reduced the need for FB IMRT from 68% to 18%. As compared to FB 3DCRT, DIBH 3DCRT resulted in in equivalent target coverage with significantly lower lung and liver doses. FB IMRT is useful to keep the right lung V20 within acceptable limits at the expense of higher dose to other OARs. Our data support the routine acquisition of DIBH scans in RBC patients undergoing RNI in order to decrease the proportion of patients that require FB IMRT.

Citation Format: Sachin R Jhawar, Kylee Lindsey, Karla Kuhn, Kayla Tedrick, Ian Zoller, William Taylor, Eric Cochran, Erin Healy, Sasha Beyer, Julia White, Jose G Bazan. Should deep inspiration breath hold scans be standardly acquired for right-sided breast/chestwall and regional nodal irradiation? [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-02.

Thyroid-optimized and thyroid-sparing radiotherapy in oral cavity and oropharyngeal carcinoma: A dosimetric study

BACKGROUND

Radiation-induced hypothyroidism is a common toxicity of head and neck radiation. Our re-planning study aimed to reduce thyroid dose while maintaining target coverage with IMRT.

METHODS

We retrospectively identified patients with oral-cavity (n = 5) and oropharyngeal cancer (n = 5). Treatment plans were re-optimized with 45 Gy thyroid mean dose constraint, then we cropped the thyroid out of PTVs and further reduced thyroid dose. Target coverage was delivering 100% dose to ≥ 93% of PTV and 95% of dose to > 99% of PTV.

RESULTS

Originally, average mean dose to thyroid was 5580 cGy. In model I, this dropped to 4325 cGy (p < 0.0001). In model II, average mean dose was reduced to 3154 cGy (p < 0.0001). For PTV low and PTV int, all had acceptable target coverage.

CONCLUSION

In patients with oral-cavity and oropharyngeal cancers, mean dose could be significantly reduced using a thyroid-optimized or thyroid-sparing IMRT technique with adequate coverage.

De-escalation of radiation therapy in patients with stage I, node-negative, HER2-positive breast cancer

In the modern era, highly effective anti-HER2 therapy is associated with low local-regional recurrence (LRR) rates for early-stage HER2+ breast cancer raising the question of whether local therapy de-escalation by radiation omission is possible in patients with small-node negative tumors treated with lumpectomy. To evaluate existing data on radiation omission, we used the National Cancer Database (NCDB) to test the hypothesis that RT omission results in equivalent overall survival (OS) in stage 1 (T1N0) HER2+ breast cancer. We excluded patients that received neoadjuvant systemic therapy. We stratified the cohort by receipt of adjuvant radiation. We identified 6897 patients (6388 RT; 509 no RT). Patients that did not receive radiation tended to be ≥70 years-old (odds ratio [OR] = 3.69, 95% CI: 3.02-4.51, p < 0.0001), to have ≥1 comorbidity (OR = 1.33, 95% CI: 1.06-1.68, p = 0.0154), to be Hispanic (OR = 1.49, 95% CI: 1.00-2.22, p = 0.049), and to live in lower income areas (OR = 1.32, 95% CI: 1.07-1.64, p = 0.0266). Radiation omission was associated with a 3.67-fold (95% CI: 2.23-6.02, p < 0.0001) increased risk of death. While other selection biases that influence radiation omission likely persist, these data should give caution to radiation omission in T1N0 HER2+ breast cancer.

Analysis of Radiation Dose to the Shoulder by Treatment Technique and Correlation With Patient Reported Outcomes in Patients Receiving Regional Nodal Irradiation

Background/Purpose

Shoulder/arm morbidity is a late complication of breast cancer treatment with surgery and regional nodal irradiation (RNI). We set to analyze the impact of radiation technique [intensity modulated radiation therapy (IMRT) or 3D conformal radiation therapy (3DCRT)] on radiation dose to the shoulder with a hypothesis that IMRT use results in smaller volume of shoulder receiving radiation. We explored the relationship of treatment technique on long-term patient-reported outcomes using the quick disabilities of the arm, shoulder, and hand (q-DASH) questionnaire.

Materials/Methods

We identified patients treated with adjuvant RNI (50 Gy/25 fractions) from 2013 to 2018. We retrospectively contoured the shoulder organ-at-risk (OAR) from 2 cm above the ipsilateral supraclavicular (SCL) planning target volume (PTV) to the inferior SCL PTV slice and calculated the absolute volume of shoulder OAR receiving 5–50 Gy (V5–V50). We identified patients that completed a q-DASH questionnaire ≥6 months from the end of RNI.

Results

We included 410 RNI patients: 54% stage III, 72% mastectomy, 35% treated with IMRT. IMRT resulted in significant reductions in the shoulder OAR volume receiving 20–50 Gy vs. 3DCRT. In total, 82 patients completed the q-DASH. The mean (SD) q-DASH=25.4 (19.1) and tended to be lower with IMRT vs. 3DCRT: 19.6 (16.4) vs. 27.8 (19.8), p=0.078.

Conclusion

We found that IMRT reduces radiation dose to the shoulder and is associated with a trend toward reduced q-DASH scores ≥6 months post-RNI in a subset of our cohort. These results support prospective evaluation of IMRT as a technique to reduce shoulder morbidity in breast cancer patients receiving RNI.

Abstract PS15-04: De-escalation of radiation therapy in patients with stage I, node-negative, HER2-positive breast cancer: Patterns of care and survival outcomes using the national cancer database

Background: In the modern era, highly effective anti-HER2 therapy is associated with very low local-regional recurrence (LRR) rates for early-stage HER2+ breast cancer. One recent prospective study of T1-2N0 HER2+ breast cancer patients treated with lumpectomy and adjuvant paclitaxel+trastuzumab followed by whole breast radiation (RT) demonstrated 7-year LRR-free survival of 99% raising the question of whether local therapy de-escalation by RT omission is possible. To evaluate existing data on radiation omission, we used the National Cancer Database (NCDB) to test the hypothesis that RT omission results in equivalent overall survival (OS) in stage 1 (T1N0) HER2+ breast cancer.Materials/Methods: We identified patients with stage I (T1N0) HER2+ breast cancer treated with lumpectomy, adjuvant chemotherapy and anti-HER2 therapy from 2013 (the first year anti-HER2 therapy receipt was reliably collected) to 2015. We excluded patients that received neoadjuvant systemic therapy. We then stratified the cohort by receipt of adjuvant RT. The primary endpoint was OS as LRR is not captured by the NCDB. OS was analyzed by the Kaplan-Meier method (RT and RT omission groups compared by the log-rank test) and multivariate cox regression including variables with p&lt;0.20 on univariate analysis (hazard ratios [HR], and 95% confidence intervals [CI] are reported). Propensity score matched (PSM) analysis with patients matched on age (≥70 vs. &lt;70), comorbidities (≥1 vs. 0), grade (3 vs. 1-2), tumor size (&gt;1 cm vs. ≤1 cm), ER/PR status (ER-/PR- vs. ER+ and/or PR+), facility type (academic vs. non-academic), and income (&lt;$46,000/yr vs. ≥46,000/yr) was performed as an independent test of the Cox regression analysis.Results: We identified 6,897 patients that met the study criteria (6,388 RT; 509 no RT). Patients that did not receive RT tended to be older (mean age 64.0 years v. 59.2 years, p&lt;0.0001), have ≥1 comorbidity (21.4% vs. 14.8%, p&lt;0.0001), and live in lower income areas (60.1% vs. 52%, p=0.0004). Median follow-up was 29.4 months (IQR=19.5-39.9 months) with 155 deaths (95 RT; 60 RT omission). The 2-year OS was significantly worse for patients with RT omission (89.0% vs. 99.2%, p&lt;0.0001). Factors associated with OS on univariate analysis included RT omission (p&lt;0.0001), age≥70 (p&lt;0.0001), ≥1 comorbidity (p=0.0002), tumor size&gt;1cm (p=0.14), grade 3 tumors (p=0.14), academic facility (p=0.16) and lower income (p=0.02) but not ER-/PR- status (HR=1.01, p=0.95), distance to treatment facility (p=0.42) or tumor laterality (p=0.66). On multivariate analysis, RT omission (HR=7.55, 95% CI 5.36-10.63, p&lt;0.0001), age≥70 (HR=2.30, 95% CI 1.63-3.23, p&lt;0.0001), and ≥1 comorbidity (HR=1.45, 95% CI 1.00-2.09, p=0.05) remained independently associated with higher risk of death. The PSM cohort consisted of 509 pairs of patients with 73 deaths (13 RT; 60 RT omission) and median follow-up 26.4 months (IQR, 16.5-37.3 months). RT omission remained associated with a 5.42-fold (95% CI 3.02-9.73, p&lt;0.0001) increased risk of death in the PSM cohort.Conclusion: This study demonstrates that RT omission is independently associated with an increased risk of death in patients with stage I, HER2+, node-negative breast cancer treated with lumpectomy, adjuvant chemotherapy and anti-HER2 therapy. Patients that did not receive RT tended to be older, have more comorbidities and live in lower income areas. While other selection biases that influence RT omission likely persist, these data should give caution to RT omission in stage I, node-negative HER2+ breast cancer.

Citation Format: Jose G Bazan, Sachin Jhawar, Daniel Stover, Ko Un Park, Sasha Beyer, Erin Healy, Julia R White. De-escalation of radiation therapy in patients with stage I, node-negative, HER2-positive breast cancer: Patterns of care and survival outcomes using the national cancer database [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS15-04.

Toxicity and outcomes associated with high-dose rate brachytherapy for medically inoperable endometrial cancer

PURPOSE

To evaluate toxicity in inoperable endometrial cancer (EC) treated with definitive radiation therapy (RT).

MATERIALS AND METHODS

Patients treated with definitive RT for EC were retrospectively reviewed. EQD2 values were calculated for bladder, rectum, and sigmoid. Acute and late toxicities were retrospectively graded. Descriptive statistical analysis was performed.

RESULTS

Fifty-one patients were included. The majority of patients had endometrioid histology (N = 46, 90.2%) and Grade 1 disease (N = 32, 62.75%). Thirty-seven patients (72.5%) were treated with image-guided BT (IGBT) and 14 (27.5%) with two-dimensional BT. Forty patients (78.4%) received EBRT + BT and 11 (21.57%) received BT alone. No grade 2 (G2) or higher toxicities were reported with BT alone. G2 or higher acute toxicities with EBRT + BT were G2 proctitis (N = 2, 5.0%) and G3 proctitis (N = 1, 2.5%). Late toxicities included G3 vaginal stenosis (N = 1, 2.5%), proctitis (N = 1, 2.5%), enteritis (N = 1, 2.5%), and one G4 gastrointestinal bleed. One- and 2-year local control were 100% with BT alone and 93% and 89%, respectively, with EBRT + BT. One- and 2-year locoregional control were 100% with BT and 97% and 93%, respectively, with EBRT + BT. Recurrence-free survival was 89% at 1 and 2 years with BT alone compared to 87% and 80% with EBRT + BT. One- and 2-year overall survival were 88% and 72% with BT alone compared to 94% and 84% with EBRT + BT. There were no statistically significant differences in cancer control between the two groups.

CONCLUSIONS

Women with inoperable EC treated with definitive RT have low toxicity rates and durable local control.

Dosimetric parameters associated with radiation-induced esophagitis in breast cancer patients undergoing regional nodal irradiation

BACKGROUND/PURPOSE

Rates of acute esophagitis in breast cancer patients undergoing regional nodal irradiation (RNI) are under-reported. We set to identify esophageal dose-volume constraints associated with grade 2 esophagitis (G2E). We hypothesized that the G2E rate was higher with intensity modulated radiation therapy (IMRT) vs. 3D conformal radiation therapy (3DCRT).

MATERIALS/METHODS

We identified patients that received RNI (50 Gy/25 fractions) from 1/2013 to 6/2019. We retrospectively contoured the esophagus in a consistent manner and recorded esophageal mean dose, max dose, and V10-V50. Our primary endpoint was the G2E rate. Receiver operating characteristics curves analysis (e.g., Youden's J statistic) were used to determine the cutpoints for the dosimetric parameters which were then tested in logistic regression models.

RESULTS

We identified 531 patients (50% left-sided; 41% IMRT; 16.2% G2E). G2E was significantly higher in IMRT vs. 3DCRT patients (23.6% vs. 10.9%, p < 0.0001). All esophageal dosimetric parameters were significantly associated with G2E after adjusting for age and laterality. The cutpoints for esophageal mean dose, V10 and V20 were 11 Gy, 30%, and 15%, respectively. The associations between the dichotomized dose-volume parameters and G2E were OR = 3.82 (95% CI 2.28-6.40, p < 0.0001) for esophageal mean dose, OR = 5.37 (95% CI 3.01-9.58, p < 0.0001) for esophageal V10, and OR = 3.23 (95% CI 1.93-5.41, p < 0.0001) for esophageal V20.

CONCLUSION

In patients receiving RNI with modern techniques, we found that G2E occurs in >15%, and more frequently with IMRT. These data strongly support the routine contouring of the esophagus in RNI planning, and our constraints should be incorporated in future prospective protocols of RNI.

A series of typical and atypical cases of Bazex syndrome: Identifying the red herring to avoid delaying cancer treatment

Bazex syndrome is a rare paraneoplastic dermatosis that precedes diagnosis of cancer. Awareness of this syndrome is important, as it allows early detection of underlying malignancy and may prevent misdiagnosis and delays in cancer treatment.

Identification of proteins associated with development of metastasis from cutaneous squamous cell carcinomas (cSCCs) via proteomic analysis of primary cSCCs

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers capable of metastasizing. Proteomic analysis of cSCCs can provide insight into the biological processes responsible for metastasis, as well as future therapeutic targets and prognostic biomarkers.

OBJECTIVES

To identify proteins associated with development of metastasis in cSCC.

METHODS

A proteomic-based approach was employed on 105 completely excised, primary cSCCs, comprising 52 that had metastasized (P-M) and 53 that had not metastasized at 5 years post-surgery (P-NM). Formalin-fixed, paraffin-embedded cSCCs were microdissected and subjected to proteomic profiling after one-dimensional (1D), and separately two-dimensional (2D), liquid chromatography fractionation.

RESULTS

A discovery set of 24 P-Ms and 24 P-NMs showed 144 significantly differentially expressed proteins, including 33 proteins identified via both 1D and 2D separation, between P-Ms and P-NMs. Several differentially expressed proteins were also associated with survival in SCCs of other organs. The findings were verified by multiple reaction monitoring on six peptides from two proteins, annexin A5 (ANXA5) and dolichyl-diphosphooligosaccharide-protein glycosyltransferase noncatalytic subunit (DDOST), in the discovery group and validated on a separate cohort (n = 57). Increased expression of ANXA5 and DDOST was associated with reduced time to metastasis in cSCC and decreased survival in cervical and oropharyngeal cancer. A prediction model using ANXA5 and DDOST had an area under the curve of 0·93 (confidence interval 0·83-1·00), an accuracy of 91·2% and higher sensitivity and specificity than cSCC staging systems currently in clinical use.

CONCLUSIONS

This study highlights that increased expression of two proteins, ANXA5 and DDOST, is significantly associated with poorer clinical outcomes in cSCC.

Clinical Effectiveness of an Adaptive Treatment Planning Algorithm for Intensity Modulated Radiation Therapy Versus 3D Conformal Radiation Therapy for Node-Positive Breast Cancer Patients Undergoing Regional Nodal Irradiation/Postmastectomy Radiation Therapy

PURPOSE

Clinical trials support adjuvant regional nodal irradiation (RNI) after breast-conserving surgery or mastectomy for patients with lymph node-positive breast cancer. Advanced treatment planning techniques (eg, intensity modulated radiation therapy [IMRT]) can reduce dose to organs at risk (OARs) in this situation. However, uncertainty persists about when IMRT is clinically indicated (vs 3-dimensional conformal radiation therapy [3DCRT]) for RNI. We hypothesized that an adaptive treatment planning algorithm (TPA) for IMRT adoption would allow OAR constraints for RNI to be met when 3DCRT could not without significantly changing toxicity and locoregional recurrence (LRR) patterns.

METHODS AND MATERIALS

Since 2013, all RNI patients also underwent an adaptive TPA that began with 3DCRT and then changed to IMRT when OAR constraints (mean heart dose ≤500 cGy; ipsilateral lung V20 ≤35%) could not be met. Patients received 2 Gy/d to the prospectively contoured target volumes (including internal mammary nodes). We retrospectively evaluated the dosimetry and clinical outcomes of the treatment groups (IMRT vs 3DCRT). The primary endpoint was the cumulative incidence of LRR as the site of first recurrence, and we specifically address patterns of failure based on dose to the posterior supraclavicular nodal region (SCL-post).

RESULTS

Two hundred forty patients (60% stage III; mean 4.0 + nodes) underwent an adaptive-TPA for RNI after mastectomy (74%) or breast-conserving surgery (26%), resulting in 168 patients treated with 3DCRT and 72 patients treated with IMRT. There were 7 LRRs (2 IMRT, 5 3DCRT) resulting in 4-year LRR of 2.8% for IMRT versus 1.8% for 3DCRT (P = .99). Three patients (2 IMRT, 1 3DCRT) had SCL nodal failures (1 in the SCL-post).

CONCLUSIONS

An adaptive TPA for use of IMRT when 3DCRT does not meet critical OAR constraints resulted in rare high-grade toxicity and no difference in failure patterns between patients treated with IMRT and 3DCRT. These data should provide reassurance that IMRT maintains the therapeutic ratio by preserving cancer control outcomes without excess toxicity when 3DCRT fails to meet OAR constraints.

Primary vs nodal site PET/CT response as a prognostic marker in oropharyngeal squamous cell carcinoma treated with intensity-modulated radiation therapy

BACKGROUND

Positron emission tomography/computed tomography (PET/CT) in staging of advanced oropharyngeal squamous cell carcinoma (OPSCC) and at 3 months posttreatment (PETpost) is often utilized to assess response. The significance of lymph node vs primary site treatment response is incompletely understood.

METHODS

We reviewed 230 patients treated with radiation therapy. PETpost response was graded at primary and nodal sites and correlated with survival.

RESULTS

Median age was 58, and 83% were p16-positive. Median follow-up was 24.3 months. Nodal response at PETpost predicted improved 2-year local recurrence-free survival (LRFS) (93% vs 72%, P =.004), 2-year disease-free survival (DFS) (80% vs 61.3%, P =.021), and 2-year overall survival (OS) (89% vs 83%, P =.051), while primary response only predicted improved 2-year LRFS (91% vs 76% P = .035).

CONCLUSION

In OPSCC patients, both nodal and primary response at 3 months on PET/CT predicted for improved LRFS, but only nodal response predicted DFS and OS.

Platinum-based regimens versus cetuximab in definitive chemoradiation for human papillomavirus-unrelated head and neck cancer

For patients ineligible for cisplatin with definitive radiotherapy (CP-CRT) for locally advanced head and neck squamous cell carcinoma (LA-HNSCC), concurrent cetuximab (C225-RT) is a popular substitute. Carboplatin-based chemoradiation (CB-CRT) is another option; however, relative efficacies of CP-CRT, CB-CRT and C225-RT are unclear, particularly in the human papillomavirus (HPV)-unrelated population. We identified 316 patients with stage III-IVB cancers of the oropharynx (24.7%), larynx (58.2%) and hypopharynx (17.1%) undergoing definitive C225-RT (N = 61), CB-CRT (N = 74) or CP-CRT (N = 181). Kaplan-Meier and cumulative incidence functions were generated to estimate overall survival (OS), locoregional failure (LRF) and distant metastasis (DM). Cox proportional hazards were used to determine the association of survival endpoints with clinical characteristics. Respectively, 3-year cumulative incidences for CP-CRT, CB-CRT and C225-RT were: LRF (0.19, 0.18 and 0.48, p ≤ 0.001), DM (0.17, 0.12 and 0.25, p = 0.32). Kaplan-Meier estimates for 3 year OS were: CP-CRT: 71%; CB-CRT: 59% and C225-RT: 54%; p = 0.0094. CP-CRT (hazard ratio [HR] 0.336; 95% confidence interval [CI] 0.203-0.557, p < 0.01) and CB-CRT (HR 0.279; 95% CI 0.141-0.551, p < 0.01) were associated with reduced hazard for LRF on multivariable analysis. CP-CRT (HR 0.548; 95% CI 0.355-0.845, p < 0.01) and CB-CRT (HR 0.549; 95% CI 0.334-0.904, p = 0.02) were associated with a reduced hazard for death on multivariable analysis. Propensity matching confirmed reduced hazards with a combined CP/CB-CRT group compared to C225-RT for LRF: HR 0.384 (p = 0.018) and OS: HR 0.557 (p = 0.045) and CB-CRT group compared to C225-RT for LRF: HR 0.427 (p = 0.023). In conclusion, CB-CRT is an effective alternative to CP-CRT in HPV-unrelated LA-HNSCC with superior locoregional control and OS compared to C225-RT.

The PROCLIPI international registry of early-stage mycosis fungoides identifies substantial diagnostic delay in most patients

BACKGROUND

Survival in mycosis fungoides (MF) is varied and may be poor. The PROCLIPI (PROspective Cutaneous Lymphoma International Prognostic Index) study is a web-based data collection system for early-stage MF with legal data-sharing agreements permitting international collaboration in a rare cancer with complex pathology. Clinicopathological data must be 100% complete and in-built intelligence in the database system ensures accurate staging.

OBJECTIVES

To develop a prognostic index for MF.

METHODS

Predefined datasets for clinical, haematological, radiological, immunohistochemical, genotypic, treatment and quality of life are collected at first diagnosis of MF and annually to test against survival. Biobanked tissue samples are recorded within a Federated Biobank for translational studies.

RESULTS

In total, 430 patients were enrolled from 29 centres in 15 countries spanning five continents. Altogether, 348 were confirmed as having early-stage MF at central review. The majority had classical MF (81·6%) with a CD4 phenotype (88·2%). Folliculotropic MF was diagnosed in 17·8%. Most presented with stage I (IA: 49·4%; IB: 42·8%), but 7·8% presented with enlarged lymph nodes (stage IIA). A diagnostic delay between first symptom development and initial diagnosis was frequent [85·6%; median delay 36 months (interquartile range 12-90)]. This highlights the difficulties in accurate diagnosis, which includes lack of a singular diagnostic test for MF.

CONCLUSIONS

This confirmed early-stage MF cohort is being followed-up to identify prognostic factors, which may allow better management and improve survival by identifying patients at risk of disease progression. This study design is a useful model for collaboration in other rare diseases, especially where pathological diagnosis can be complex.

Abstract P3-12-03: Analysis of radiation dose in the gap region between the supraclavicular target volume to the internal mammary target volume in women receiving regional nodal irradiation

Purpose: Consensus guidelines for regional nodal irradiation (RNI)/postmastectomy radiation (PMRT) clinical target volumes (CTV) have slight variations amongst leading national organizations. In the US, the Radiation Therapy Oncology Group (RTOG) defines the caudal edge of the supraclavicular (SCV) CTV as the junction of the brachiocephalic and axillary vessels while the internal mammary nodal (IMN) CTV starts at the superior aspect of the medial first rib. This leaves an anatomical gap between the two target volumes. The European Society of Radiation Oncology (ESTRO) does not recommend leaving a gap between the SCV CTV and IMN CTV. We set to analyze radiation dose and patterns of failure in this region.

Materials and Methods: We identified consecutive patients treated with RNI/PMRT at our institution from 2013-2016. Patients with metastatic or recurrent disease were excluded. All patients received 50 Gy/25 fractions to the breast/chestwall+regional nodes (including IMN PTV) +/- boost to the lumpectomy cavity/mastectomy scar using 3D conformal radiotherapy (3DCRT) or intensity modulated radiation therapy (IMRT). We retrospectively contoured the vessels from one slice below the caudal border of the SCV PTV contour to one slice cranial to the first IMN PTV contour. We calculated the mean dose and the relative V40Gy, V45Gy, and V47.5Gy of the gap region.A gap failure was defined as a first recurrence in this region with or without simultaneous loco-regional recurrence (LRR) or distant metastases (DM). We used the cumulative incidence method to calculate the gap recurrence rate with DM, LRR, and death, as competing risks.

Results: 230 patients were included with median age 52 years, predominantly stage III disease (60%), and most treated with preoperative (51%) or postoperative (41%) systemic therapy. Breast cancer subtype was ER+/HER2- in 138 patients, triple negative in 44 patients, and HER2+ in 48 patients. The median (IQR) mean dose, V40Gy, V45Gy, and V47.5 Gy in the gap region were: 20.3 Gy (14.8-26.2 Gy), 6% (1.3%-20.0%), 0.6% (0%-7.0%), and 0% (0%-1.3%). The mean dose to the gap region was slightly higher in patients treated with IMRT (N=68) compared to 3DCRT (N=162): 25.3 Gy (SD 7.5 Gy) vs. 19.5 Gy (SD 8.0 Gy), p&lt;0.0001. With median follow-up of 32 months, there were 2 recurrences in the gap region, both of which occurred with simultaneous distant metastases. No patients had isolated recurrences in the gap region. The 3-year cumulative incidence of recurrence in the gap region was 0.8%. The predominant pattern of failure was DM (N=31) with a 3-year rate of 14.4% followed by LRR (N=6, 4 with simultaneous distant metastases) with a 3-year rate of 3.1%.

Conclusion: In a clinical practice in which we routinely contour and treat the IMN PTV and SCV PTV with a gap region between those two volumes, we found that the mean radiation dose to this region is low, at about 50% or less compared to the prescription dose. Despite this, recurrences in this region are exceedingly uncommon and have not yet occurred in the absence of simultaneous DM. While the follow-up is limited, these data support the current guidelines of not routinely targeting this region.

Citation Format: Bazan JG, Dicostanzo D, Healy E, Beyer S, White JR. Analysis of radiation dose in the gap region between the supraclavicular target volume to the internal mammary target volume in women receiving regional nodal irradiation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-03.

Abstract P3-12-04: Analysis of radiation dose to the shoulder by treatment technique and correlation with patient reported outcomes in patients receiving regional nodal irradiation

Background: Shoulder/arm morbidity is a late complication of breast cancer treatment. Postmastectomy radiation therapy (PMRT)/regional nodal irradiation (RNI) increases dose to the muscles and soft tissues of the shoulder and upper neck and back. Most patients are treated with 3D conformal radiation therapy (3DCRT) or Intensity modulated radiation therapy (IMRT). Here, we set to analyze the impact of 3DCRT vs. IMRT on radiation dose to the shoulder, and to retrospectively explore the relationship of treatment technique on long term patient-reported outcomes in the subset of patient who had completed the quick Disabilities of the Arm, Shoulder, and Hand (q-DASH) questionnaire.

Materials/Methods: We identified consecutive patients in our department treated with PMRT/RNI for curative intent from 2013-2016. We excluded patients treated for recurrent disease, those with metastatic disease, and those with unresected disease in the supraclavicular (SCV) fossa and/or axillary apex requiring a radiation boost to that area. We contoured the shoulder as all of the muscles/soft tissue/bone from 2 cm above the ipsilateral SCV planning target volume (PTV) to the cranial aspect of the breast or chestwall PTV. No planning constraints were set for the shoulder since this was retrospectively contoured. We used the dose volume histogram to determine the volume of shoulder receiving at least 5 Gy, 10 Gy,...,50 Gy (V5-V50, respectively). We identified patients that completed a q-DASH questionnaire ≥6 months from the end of PMRT/RNI. Descriptive statistics were used to summarize the shoulder dose and q-DASH values. Differences between groups were assessed by the t-test or chi-square test with p&lt;0.05 considered significant.

Results: We found 237 patients treated with PMRT/RNI with median age of 52 y (IQR 44-60 y), 75% treated with mastectomy, 85% had axillary lymph node dissection (ALND), median of 18 nodes removed (IQR 12-26). All patients received 50 Gy/25 fractions. A total of 68 patients (28.7%) were treated with IMRT. IMRT significantly reduced the V20-V50 to the shoulder vs. 3DCRT (e.g., V45Gy=21.7 mL vs. 208.4 mL, p&lt;0.0001). Of the 237 patients, 66 had completed a q-DASH at least 6 months from the end of radiation therapy (median, 14.5 months). Patients that completed the q-DASH vs. not were similar in age (p=0.29), number of nodes removed (p=0.17), use of ALND (p=0.13), use of chemotherapy (p=0.49) and use of mastectomy (p=0.22). The median (IQR) and mean (SD) q-DASH were 20.5 (6.8-38.6) and 24.3 (20.2) for all patients; 20.5 (9.1-38.6) and 24.1 (19.4) for the 53 mastectomy patients; 18.2 (4.5-45.5) and 25.2 (24.2) for the 13 lumpectomy patients. Most patients (N=49) were treated with 3DCRT. Compared to patients treated with 3DCRT, IMRT patients had a trend towards lower q-DASH mean scores: 16.9 vs. 26.9, p=0.077.

Conclusion: In summary, we found that IMRT reduces radiation dose to the shoulder and is associated with a trend towards reduced q-DASH scores at least 6 months after PMRT/RNI in a subset of our cohort. These results support prospective evaluation of IMRT as a technique to reduce shoulder morbidity in breast cancer patients receiving PMRT/RNI.

Citation Format: Bazan JG, Dicostanzo D, Hock K, Healy E, Beyer S, White JR. Analysis of radiation dose to the shoulder by treatment technique and correlation with patient reported outcomes in patients receiving regional nodal irradiation [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-04.

Abstract P1-12-13: Initial report of a prospective, pilot study of patient-reported upper extremity dysfunction in women undergoing radiation for breast cancer

Objectives: Upper extremity dysfunction (UED) is a known side effect of breast cancer treatment. It is unclear, however, to what degree radiation contributes to this morbidity. We aimed to characterize the level of UED using patient-reported outcomes (PROs) prior to, during, and after treatment with radiation for breast cancer. Our secondary aims were to evaluate the association of UED with pain scores.

Methods: This is a single-institution, prospective, longitudinal cohort study of patients treated with radiation for breast cancer. The validated patient-reported outcome measure, Quick Disabilities of the Arm, Shoulder and Hand (QD) was used to capture UED prior to radiation, at the end of radiation, and 1 month following the completion of radiation. Pain scores were also collected at these intervals using the numeric pain reporting scale (NPRS) from 0 (no pain) to 10 (worst pain).

Results: Forty-four patients were enrolled on this study and 43 (97.7%) had completed radiation at the time of analysis. Thirteen patients (29.5%) were treated with mastectomy, axillary lymph node dissection and regional nodal irradiation in the supine position. The other 31 (70.5%) patients underwent lumpectomy and sentinel lymph node biopsy. Of these patients, 26 (83.9%) were treated in the prone position and 30 (96.8%) received whole breast irradiation. Median time from surgery to radiation was 69 days (range 35 – 212 days), 76 days for mastectomy and 68 days for lumpectomy. Median time from start to end of radiation was 38 days for mastectomy and 28 days for lumpectomy. Pre-treatment median QD score prior to radiation was 12.5 (11.4 for lumpectomy, 15.9 for mastectomy), 9.1 at the end of radiation (9.1 for lumpectomy, 18.2 for mastectomy), and 2.4 at 1 month after radiation (2.3 for lumpectomy, 2.5 for mastectomy). Median NPRS scores at pre-treatment, post-treatment and 1 month follow-up were 1, 1, and 1 for lumpectomy and 0, 1, 0 for mastectomy patients, respectively.

Conclusion: In this initial pilot study with 1 month of follow up, patient-reported UED as demonstrated by QD scores were higher pre-radiation and decreased by one month after. This likely reflects recuperation after surgical procedure. Median average pain scores were low at all time points. Further evaluation of UED over time to characterize the long-term effect of radiation and correlation with quality of life and other clinical factors is planned.

Citation Format: Healy E, Pan X, Beyer S, Washington I, Bazan J, White J. Initial report of a prospective, pilot study of patient-reported upper extremity dysfunction in women undergoing radiation for breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-12-13.