Improved long-term patient-reported health and well-being outcomes of early-stage breast cancer treated with partial breast proton therapy

Quantification of breast lymphoedema following conservative breast cancer treatment: a systematic review

PURPOSE

Breast lymphoedema is a possible side effect of breast conserving surgery, but it is poorly understood. This is due, in part, to difficulty assessing the breast. This systematic review described outcome measures that quantify breast lymphoedema signs and symptoms and evaluated the measurement properties for these outcome measures.

METHOD

Seven databases were searched using terms in four categories: breast cancer, lymphoedema and oedema, clinician reported (ClinROM) and patient reported outcome measures (PROM) and psychometric and measurement properties. Two reviewers independently reviewed studies and completed quality assessments. The Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) methodology was used for studies including measurement property evidence.

RESULTS

Fifty-six papers were included with thirteen questionnaires, eight patient-reported rating scales, seven physical measures, seven clinician-rating scales and four imaging techniques used to quantify breast lymphoedema. Based on COSMIN methodology, one ClinROM had sufficient reliability, ultrasound measuring dermal thickness. Tissue dielectric constant (TDC) measuring local tissue water had promising reliability. Four questionnaires had sufficient content validity (BLYSS, BLSQ, BrEQ and LYMQOL-Breast).

CONCLUSIONS

Ultrasound is recommended to reliably assess breast lymphoedema signs. No PROM can be recommended with confidence, but BLYSS, BLSQ, BrEQ and LYMQOL-Breast are promising. Further research is recommended to improve evidence of measurement properties for outcome measures.

IMPLICATIONS FOR CANCER SURVIVORS

There are many approaches to assess breast lymphoedema, but currently, only ultrasound can be recommended for use, with others, such as TDC and questionnaires, showing promise. Further research is required for all approaches to improve evidence of measurement properties.

Patient-Reported Outcomes of Omission of Breast Surgery Following Neoadjuvant Systemic Therapy: A Nonrandomized Clinical Trial

Importance

Patients should have an active role in decisions about pursuing or forgoing specific therapies in treatment de-escalation trials.

Objective

To evaluate longitudinal patient-reported outcomes (PROs) encompassing decisional comfort and health-related quality of life (HRQOL) among patients who elected to enroll in a clinical trial evaluating radiotherapy alone, without breast surgery, for invasive breast cancers with exceptional response to neoadjuvant systemic therapy (NST).

Design, Setting, and Participants

Prospective, single-group, phase 2 clinical trial at 7 US medical centers. Women aged 40 years or older with invasive cT1-2 N0-1 M0 triple-negative or human epidermal growth factor receptor 2 (ERBB2)-positive breast cancer with no pathologic evidence of residual disease following standard NST enrolled from March 6, 2017, to November 9, 2021. Validated PRO measures were administered at baseline and 6, 12, and 36 months post-radiotherapy. Data were analyzed from January to February 2023.

Interventions

PRO measures included the Decision Regret Scale (DRS), Functional Assessment of Cancer Therapy-Lymphedema (FACT-B+4), and Breast Cancer Treatment Outcomes Scale (BCTOS).

Main Outcomes and Measures

Changes in PRO measure scores and subscores over time.

Results

Among 31 patients, the median (IQR) age was 61 (56-66) years, 26 (84%) were White, and 26 (84%) were non-Hispanic. A total of 15 (48%) had triple-negative disease and 16 (52%) had ERBB2-positive disease. Decisional comfort was high at baseline (median [IQR] DRS score 10 [0-25] on a 0-100 scale, with higher scores indicating higher decisional regret) and significantly increased over time (median [IQR] DRS score at 36 months, 0 [0-20]; P < .001). HRQOL was relatively high at baseline (median [IQR] FACT-B composite score 121 [111-134] on a 0-148 scale, with higher scores indicating higher HRQOL) and significantly increased over time (median [IQR] FACT-B score at 36 months, 128 [116-137]; P = .04). Perceived differences between the affected breast and contralateral breast were minimal at baseline (median [IQR] BCTOS score 1.05 [1.00-1.23] on a 1-4 scale, with higher scores indicating greater differences) and increased significantly over time (median [IQR] BCTOS score at 36 months, 1.36 [1.18-1.64]; P < .001). At 36 months postradiotherapy, the cosmetic subscore was 0.45 points higher than baseline (95% CI, 0.16-0.74; P = .001), whereas function, pain, and edema subscores were not significantly different than baseline.

Conclusions and Relevance

In this nonrandomized phase 2 clinical trial, analysis of PROs demonstrated an overall positive experience for trial participants, with longitudinal improvements in decisional comfort and overall HRQOL over time and minimal lasting adverse effects of therapy.

Trial Registration

ClinicalTrials.gov Identifier: NCT02945579.

Early Toxicity and Patient-Reported Cosmetic Outcomes in Patients Treated With Adjuvant Proton-Based Radiotherapy After Breast-Conserving Surgery

INTRODUCTION

To evaluate the dosimetric data, early toxicity, and patient-reported cosmetic outcomes in breast cancer patients treated with adjuvant proton-based radiotherapy (RT) after breast-conserving surgery.

MATERIALS AND METHODS

We performed a retrospective review of our institutional database to identify breast cancer patients treated with breast-conserving surgery followed by proton-based RT from 2015 to 2020. Patient-reported cosmetic outcomes were graded as excellent, good, fair, or poor. Early toxicity outcomes were graded by the treating physician during treatment. Dose-volume histograms were reviewed to obtain dosimetry data.

RESULTS

We identified 21 patients treated with adjuvant proton-based RT. Median whole breast dose delivered was 46.8 Gy (range, 40.0-50.4 Gy). Target volumes included the regional lymph nodes in 17 patients (81%). Seventeen patients (81%) received a lumpectomy boost. The median planning target volume V95 was 94% (range, 77%-100%), V100 71% (range, 60%-97%), V110 2% (range 0%-18%), and median max point dose was 115% (range, 105%-120%). The median ipsilateral breast V105 was 367.3 cc (range, 0-1172 cc) and V110 was 24.1 cc (range, 0-321.3 cc). Grade 2 and 3 dermatitis occurred in 62% and 14% of patients, respectively. Grade 2 and 3 pain was reported by 33% and 10% of patients, respectively. Median follow-up at the time of cosmetic evaluation was 27 months (range, 5-42 months). Four patients (21%) reported fair cosmetic outcome and 15 patients (79%) reported good or excellent cosmetic outcome. No poor cosmesis was reported.

CONCLUSION

Adjuvant proton-based radiotherapy after breast-conserving surgery is well tolerated with acceptable rates of acute toxicities and a high rate of good-to-excellent patient-reported cosmetic outcomes.

Hypofractionated proton therapy in breast cancer: where are we? A critical review of the literature

PURPOSE

To critically review available literature on hypofractionated (≥ 3 Gy/fraction) proton therapy (PT) for breast cancer (BCa).

METHODS

A systematic screening of the literature was performed in April 2021 in compliance with the preferred reporting items for systematic reviews and meta-analyses recommendations. All full-text publication written in English were considered eligible. Acute and late toxicities, oncological outcomes and dosimetric features were considered for the analysis.

RESULTS

Twelve publications met the inclusion criteria; all studies but one focused on accelerated partial breast irradiation (APBI). Eleven works considered post-operative patients, one referred to ABPI as a curative-intent modality. The dosimetric profile of PT compared favorably with both photon-based 3D conformal and intensity-modulated techniques, while a more extended follow-up is warranted to fully assess both the long-term toxicities and the non-inferiority of oncological outcomes.

CONCLUSION

Our work shows that results on PT for BCa are currently only available for APBI applications, with dosimetric analyses demonstrating a clear advantage over both 3D conformal and intensity modulated X-rays techniques, especially when ≥ 2 treatment fields were used. However, further evidence is needed to define whether such theoretical benefit translates into clinical improvements, especially in the long-term.

Proton Therapy for Partial Breast Irradiation: Rationale and Considerations

In an era of continued advancements in personalized medicine for the treatment of breast cancer, select patients with early stage breast cancer may be uniquely poised to benefit from partial breast irradiation (PBI) delivered with proton therapy. PBI presents an opportunity to improve quality of life during treatment with a significantly shorter treatment duration. By targeting less non-target breast tissue, excess radiation exposure and resulting toxicities are also reduced. Proton therapy represents a precision radiotherapy technology that builds on these advantages by further limiting the normal tissue exposure to unnecessary radiation dose not only to uninvolved breast tissue but also the underlying thoracic organs including the heart and lungs. Herein, we present a concise review of the rationale for the use of proton therapy for PBI, evidence available to date, and practical considerations in the implementation and use of proton therapy for this indication.

Cancer-related Fatigue in Breast Cancer Survivors: A Review

Fatigue has been the most distressing and frequent symptom in breast cancer (BC) survivors after treatment. Although fatigue can occur in other cancer survivors, women with a history of BC might share some distinctive features. The present study aimed to recapitulate the knowledge about risk factors and correlates of cancer-related fatigue (CRF) in BC survivors after oncologic therapy. An electronic data search was conducted in PubMed using the terms "fatigue," "breast," "cancer," and "survivors." Records were included if they were original articles, available in English, had used a quantitative scale, had > 100 participants, and had excluded women with BC relapse. BC survivors were required to have finished their treatments ≥ 2 months before, except for hormonal therapy. The physiopathology and other interventions were considered beyond the scope of our review. The correlates were subsequently classified into 7 main categories: (1) sociodemographic data, (2) physical variables, (3) tumor- and treatment-related variables, (4) comorbidities, (5) other symptoms, (6) psychological issues, and (7) lifestyle factors. Fatigue was consistently greater in younger, obese, and diabetic women. Women reporting fatigue often communicated symptoms such as pain, depression, insomnia, and cognitive dysfunction. Coping strategies such as catastrophizing could play an important role in the persistence of fatigue. However, tumor characteristics, previous treatments received, and physical activity were not consistently reported. CRF was a strong predictor of the quality of life of BC survivors after treatment. In conclusion, we found CRF was a frequent and serious symptom that severely affects the quality of life of BC survivors after treatment. Health practitioners require more awareness and information about CRF.

The risk for developing a secondary cancer after breast radiation therapy: Comparison of photon and proton techniques

BACKGROUND AND PURPOSE

To compare secondary malignancy risks of modern proton and photon therapy techniques for locally advanced breast cancer.

METHODS AND MATERIALS

We utilized dosimetric data from 34 [10 photon-VMAT, 10 photon-3DCRT, 14 pencil beam scanning proton (PBS)] breast cancer patients who received comprehensive nodal irradiation. Employing a model based on organ equivalent dose to account for both inhomogeneous organ dose distributions and non-linear functional dose relationships, we estimated excess absolute risk, excess relative risk, and lifetime attributable risk (LAR) for secondary malignancies. The model uses dose distribution, number of fractions, age at exposure, attained age, the linear-quadratic dose response relationship for cell survival, repopulation factor, as well as gender specific age dependencies, and initial slopes of dose response curves.

RESULTS

The LAR for carcinoma at age 70 was estimated to be up to 3.64% for esophagus with an advantage of 3DCRT over PBS and VMAT. For the ipsilateral lung, risks were lowest for PBS (up to 5.56%), followed by 3DCRT (up to 6.54%) and VMAT (up to 7.7%). For the contralateral lung, there is a clear advantage of 3DCRT and PBS techniques (risk <0.86%) over VMAT (up to 4.4%). The risk for the contralateral breast is negligible for 3DCRT and PBS but was estimated as up to 1.2% for VMAT. Risks for the thyroid are overall negligible. Independently performed comparative treatment plans on 10 patients revealed that the risk for the contralateral lung and breast using VMAT can be more than an order of magnitude higher compared to PBS. Sarcoma risks were estimated as well showing similar trends but were overall lower compared to carcinoma.

CONCLUSION

Conventional (3DCRT) techniques led to the lowest estimated risks of, thyroid and esophageal secondary cancers while PBS demonstrated a benefit for secondary lung and contralateral breast cancer risks, with the highest risks overall associated with VMAT techniques.

Improved long-term patient-reported health and well-being outcomes of early-stage breast cancer treated with partial breast proton therapy

Background

Because early‐stage breast cancer can be treated successfully by a variety of breast‐conservation approaches, long‐term quality of life (QoL) is an important consideration in assessing treatment outcomes for these patients. This study compares patient‐reported QoL outcomes among women with stage 0‐2 disease treated via lumpectomy followed by whole breast irradiation (WBI) or partial breast proton irradiation (PBPT).

Methods

In this cross‐sectional study, 129 participants evaluated QoL several years post‐treatment by responding to subjective instruments, including established scalar questionnaires and self‐report measures. Responses were averaged between the two groups.

Results

At 6.5 years (median) postdiagnosis, participants’ demographic, and clinical characteristics were similar. Patient‐reported outcomes were reported as mean scale scores for the two groups, all displaying significant differences favoring PBPT, including: cosmetic breast cancer treatment outcome scale (BCTOS) (PBPT mean 1.45, WBI mean 1.88, P < 0.001); breast pain (PBPT mean 1.30, WBI mean 1.67, P < 0.05); breast texture (BPT mean 1.44, WBI mean 1.91, P < 0.001); clothing fit (PBPT mean 1.06, WBI 1.46, P < 0.001); fatigue (PBPT mean 2.24, WBI mean 3.77, P < 0.002); impact of daily life fatigue on personal relations (OBPT mean 0.83, WBI mean 2.15, P < 0.001); and self‐consciousness (appearance dissatisfaction) (PBPT mean 1.38, WBI mean 1.77, P < 0.004).

Conclusion

Patients’ responses suggest that PBPT is associated with improved overall QoL compared to standard whole breast treatment. These self‐perceptions are reported by patients who are 5‐10 years post‐treatment, and that PBPT may enhance QoL in a multitude of interrelated ways.