Using Life Cycle Assessment as a Tool to Evaluate the Environmental Impact of Radiation Oncology and Inform Treatment Decision-Making in Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

The effects of climate change negatively impact patient health and healthcare delivery across the cancer care continuum. Environmental impacts arising from radiation therapy (RT), as measured with formal life cycle assessment (LCA) methods, have not been reported to date. LCA is a standardized approach to systematically analyze the effects a product or process has on the environment by accounting for all its components and their life cycle. Here, we used LCA to compare the footprint of RT delivery among several environmental impact categories, including carbon (CO2) emissions, in early-stage breast cancer (ESBC) regimens with clinical equivalency.

MATERIALS/METHODS

We used LCA methods to estimate the environmental footprint of ESBC treatments across 9 standard impact categories including greenhouse gases, ozone depletion, smog, carcinogenics, and respiratory effects, in a cohort of 50 patients receiving moderate hypofractionation (mod-hEBRT) to 42.4 Gy in 16 fractions (n = 25) and ultra-hypofractionation (ultra-hEBRT) to 26 Gy in 5 fractions (n = 25). We analyzed life-cycle emissions associated with patient and staff commute, RT quality assurance and set-up equipment, linear accelerator (LINAC) requirements, clinic supplies, and linen use. Facility emission estimates are underway. All calculations were done in SimaPro 9.4 using the ecoinvent 3.8 database and TRACI 2.1 impact assessment methods. Confidence intervals were calculated using stochastic computations.

RESULTS

Total emissions associated with delivering a full course of mod-hEBRT versus ultra-hEBRT averaged 502 kg CO2-eq (95% CI, 484 to 521) and 264 kg CO2-eq (95% CI, 252 to 277), respectively. The largest contributors to total emissions in each group were patient and staff transportation (301.8 vs 196.4 kg CO2-eq, respectively) and LINAC equipment and utilization (175 vs 55.2 kg CO2-eq, respectively). In addition, treatment with mod-hEBRT was found to have, on average, a larger environmental footprint over ultra-hEBRT across all impact categories. The leading contributor to these environmental impacts continued to be patient and staff transportation, which accounted for 91.1% of ozone depletion, 63.2% of smog, 55.3% of acidification, 86.4% of carcinogenics, 53.2% of respiratory effects, 79.7% of ecotoxicity, and 67.9% of fossil fuel depletion in mod-hEBRT.

CONCLUSION

We present the first LCA estimating the environmental footprint of mod versus ultra-hEBRT in ESBC patients. Evaluation of emissions and environmental impacts demonstrate lower carbon and environmental footprints in shorter RT courses that are otherwise clinically equivalent. These data provide the opportunity to consider practice changes in RT delivery that utilize clinically appropriate and ecologically informed regimens in the treatment of ESBC patients.

Increased Complication Rates with Proton Therapy in Breast Cancer Patients with Immediate, Implant-Based Reconstruction: Single-Institution Comparative Effectiveness Analysis

PURPOSE/OBJECTIVE(S)

To compare the impact of protons vs. photons on breast reconstruction complications, for patients (pts) receiving postmastectomy radiation (PMRT) with either single-stage direct-to-implant (DTI) or two-staged expander/implant (TE/I).

MATERIALS/METHODS

We reviewed the charts of 578 pts who underwent immediate reconstruction followed by radiation at our institution between 2010 and 2020. Pts with implant-based reconstruction using either TE/I or DTI and PMRT delivery in the presence of the prosthesis were included. Pts enrolled in active ongoing clinical trials were excluded from the analysis. The photon group received 3D conformal or IMRT/VMAT treatment with a median dose of 50-50.4 Gy in 25 to 28 fractions. For proton pts, treatment was delivered mainly with pencil beam scanning technique (PBS); few pts received passively scattered proton spread-out Bragg peak (SOBP). The complications were defined as infection/skin necrosis (I/N) requiring operative debridement, capsular contracture (CC) necessitating capsulotomy, and overall implant failure (ORF) as the removal of the permanent implant irrespective of replacement outcomes (i.e., with and without salvage reconstruction). We fit inverse-probability weighted cumulative incidence curves to adjust for confounding and non-random loss to follow-up. Various sensitivity analyses were conducted.

RESULTS

Four hundred ninety-five pts were available for the final analysis with an overall median follow-up of 55 months. 66 (13%) received protons, of which14 were treated with SOBP protons. 137 (28%) and 256 (56%) received photons with and without chest wall boost (CWB), respectively. The 5-year inverse probability-weighted risk of CC post-PMRT was 31% for protons vs. 10% for photons (RR:3.09, 95% CI: 1.77, 5.40). The 5 years ORF risk was 35.6% in protons compared to 22.7% in photons pts (RR: 1.57; 95% CI 1.0, 2.48). Hazard ratios from the adjusted Cox models were 3.79 (p<0.001) for CC and 2.05 (p<0.01) for ORF. No difference in I/N was noted between protons and photons pts. Sensitivity analysis showed that protons significantly increased CC risk vs photons both with CWB (HR:3.56, P<0.001) and without CWB (HR:3.9, p<0.001). Similar outcomes were observed with ORF, where protons increased the rate of ORF compared to photons, irrespective of CWB (HR 1.8, p = 0.038 with CWB; HR 2.4, p = 0.004 without CWB). No differences between PBS and SOBP proton techniques were noted.

CONCLUSION

Compared to photons, proton therapy increases the risk of capsular contracture requiring surgical intervention and hence overall reconstruction failure. This data should inform discussions about the risks and benefits of protons in patients with reconstruction, while awaiting mature data from ongoing clinical trials (RADCOMP) utilizing protons for breast cancer.

Proton vs. Photons for Breast Cancer Patients with Immediate, Implant-Based Reconstruction Receiving Postmastectomy Radiotherapy: A Multicenter Pooled Analysis

PURPOSE/OBJECTIVE(S)

Proton therapy improves postmastectomy radiotherapy (PMRT) normal tissue sparing compared with photon techniques. However, little is understood about its effect on reconstruction outcomes. The primary objective was to evaluate complication rates in breast cancer patients treated with proton (PRO) versus photon (PHO) PMRT following immediate, implant-based breast reconstruction.

MATERIALS/METHODS

Consecutive patients with breast cancer who underwent mastectomy and immediate reconstruction with a tissue expander (TE) or permanent implant (PI) and PRO or PHO PMRT between 2011 and 2022 were included from two institutions. Complication rate was defined as the sum of reconstruction failure (explantation without replacement), unplanned prosthesis exchange, and other unplanned revisional surgery. Each complication type was analyzed as an independent endpoint.

RESULTS

Among 733 patients, median follow-up was 4.4 years; 36.5% (267) were treated with PRO and 63.5% (466) with PHO. There was no difference in age, BMI, or comorbidities between the two groups. PRO was more likely to have had, two-stage reconstruction and pre-pectoral implant placement (p<.01). Median dose was 50-50.4 Gy in 25-28 fractions, with only 50 receiving hypofractionation. Bolus was used in all PHO patients. Regional nodes were more likely to be included in PRO (99.6% v. 83.7% PHO, p<.01). Although there was no difference in the use of chest wall boost between groups, the axillary nodes were more frequently boosted in PRO (25.1% vs 2.8% PHO, p<.01). The overall rate of complications at 4 years was 26.7% (95% CI = 23.3-30.5). The 4-year rate of reconstruction failure, unplanned exchange, and other surgery was 8.2% (95% CI = 6.3-10.7), 17.4% (95% CI = 14.6-20.8), and 12.5% (95% CI = 10.1-15.5), respectively. On MVA, PRO did not confer an increased risk of reconstruction complications compared to PHO. Significant risk factors for reconstruction failure included TE-to-autologous approach [HR versus direct-to-implant reference: 4.05 (95% CI = 1.60-10.22)], TE-to-permanent implant approach [HR = 2.06 (95% CI = 1.12-3.79)], chest wall boost [HR = 2.20 (95% CI = 1.21-4.02)], and any lymph node boost [HR = 2.33 (95% CI = 1.10-4.97)]. Compared to direct-to-implant, two-stage reconstruction was also associated with a higher rate of unplanned exchange [HR for TE/PI = 1.49 (95% CI = 1.01-2.20)] and revisional surgery [HR for TE-to-autologous = 3.95 (95% CI = 1.64-9.52)]. Prepectoral implant placement was correlated with reduced risk of revisional surgery, relative to subpectoral placement [HR = 0.42 (95% CI = 0.22-0.81)].

CONCLUSION

This represents the largest combined series to date comparing PRO and PHO PMRT. Despite a higher rate of two-stage reconstruction, nodal irradiation, and nodal boost in PRO, there was no significant difference in the risk of complications between protons and photons. Differences in PRO delivery techniques between institutions and dosimetric details such as skin dose will be presented in person.

The Financial Impact on Reimbursement of Moderately Hypofractionated Postoperative Radiation Therapy for Breast Cancer: An International Consortium Report

AIMS

Moderately hypofractionated breast irradiation has been evaluated in several prospective studies, resulting in wide acceptance of shorter treatment protocols for postoperative breast irradiation. Reimbursement for radiation therapy varies between private and public systems and between countries, impacting variably financial considerations in the use of hypofractionation. The aim of this study was to evaluate the financial impact of moderately hypofractionated breast irradiation by reimbursement system in different countries.

MATERIALS AND METHODS

The study was designed by an international group of radiation oncologists. A web-questionnaire was distributed to representatives from each country. The participants were asked to involve the financial consultant at their institution.

RESULTS

Data from 13 countries from all populated continents were collected (Europe: Denmark, France, Italy, the Netherlands, Spain, UK; North America: Canada, USA; South America: Brazil; Africa: South Africa; Oceania: Australia; Asia: Israel, Taiwan). Clinicians and/or departments in most of the countries surveyed (77%) receive remuneration based on the number of fractions delivered to the patient. The financial loss per patient estimated resulting from applying moderately hypofractionated breast irradiation instead of conventional fractionation ranged from 5-10% to 30-40%, depending on the healthcare provider.

CONCLUSION

Although a generalised adoption of moderately hypofractionated breast irradiation would allow for a considerable reduction in social and economic burden, the financial loss for the healthcare providers induced by fee-for-service remuneration may be a factor in the slow uptake of these regimens. Therefore, fee-for-service reimbursement may not be preferable for radiation oncology. We propose that an alternative system of remuneration, such as bundled payments based on stage and diagnosis, may provide more value for all stakeholders.

P4-02-04: Androgen Receptor (AR) Expression in a Cohort of Patients (pts) with Triple Negative Breast Cancer (TNBC)

Background

TNBC, defined by the absence of ER, PR, and HER2, is associated with higher risk of recurrence and BC-related mortality, earlier age at diagnosis, menarche, and 1st pregnancy, increased parity, higher BMI, and African-American/Hispanic race. TNBC is a heterogeneous group. Using gene expression analysis, our group described a subset of AR+ ER/PR- BC that exhibits androgen-dependent growth. In vitro studies confirmed the functional role of AR and showed that growth could be abrogated by antiandrogens.(Doane et al 2006) We translated this work into a phase II trial of bicalutamide in pts with AR+ ER/PR- metastatic BC (MBC). (NCT00468715) We now describe the prevalence and clinicopathological characteristics of AR+TNBC in primary disease in a single-institution retrospective cohort.

Methods: We identified 1,032 pts with resectable, TNBC (ER/PR&lt;1%; HER2&lt;2+/FISH&lt;2.2) who had surgery at MSKCC from 1998–2006. Exclusion criteria: neoadjuvant chemotherapy, prior radiation, inflammatory/MBC. IRB approval was obtained. We constructed tissue microarrays (TMA) from 210 primary tumors (&gt; 1 cm) with each tumor represented by three 0.6mm cores. AR was tested with DAKO antibody (Clone AR441; dilution 1:500). TMAs were digitized with a Mirax scanner. MetaMorph image analysis software was used to quantify the ratio of DAB staining to hematoxylin signal. A ratio &gt;1 SD above mean was defined as AR+. AR+ cores were manually reviewed; false positives due to core artifact were excluded. To evaluate clinicopathological variables and differences in recurrence-free survival (RFS) and overall survival (OS) by AR status we used chi-square/t-tests and Kaplan-Meier methods/log-rank test, respectively.

Results: 169 pts had adequate cores for image analysis/quantification of AR. 10% of pts tested AR+ (17/169). Median (med) followup: AR+=6 years (yr), AR-=5.6yr. Demographic/clinicopathological variables: Table 1 (ages in med yr). Overall med age=54yr (29-84). Adjuvant chemotherapy received: AR+ 82%, AR- 87%, p =0.40; 77% received anthracycline/taxane-based therapy. Med time to distant metastasis (DM)=2.1yr (0.2−6.2yr). We were unable to demonstrate a difference in 5yr RFS (69% vs. 77%; p=0.37) or OS (68% vs. 84%; p=0.25) between AR+ and AR- TNBC.

P5-14-13: Favorable Prognosis in Patients with T1a,b Node-Negative Triple Negative Breast Cancers Treated with Multimodality Therapy

Purpose: To evaluate the clinical characteristics, natural history and outcomes in patients with ≤1cm, node-negative triple negative breast cancer (TNBC).

Materials and Methods: After excluding patients who received neoadjuvant therapy, 1,022 TNBC patients who received definitive breast surgery from 1999 to 2006 were identified from an institutional database. Among these, 194 patients had node-negative tumors ≤1cm and comprise the study population. Clinical data was abstracted and survival outcomes were analyzed.

Results: Median follow-up time was 71 months (range 2–143). Median age at diagnosis was 55.5 years (range 27–84). T stage was T1mic in 16 (8.2%), T1a in 49 (25.3%), T1b in 129 (66.5%). The majority of tumors were poorly differentiated (N= 142, 73%), lacked lymphovascular invasion (N= 170, 87.6%) and were screening-detected (69%, N=134). Breast-conserving surgery (BCS) was employed in 129 (66.5%) and mastectomy in 65 (33.5%) patients. 113 (58%) patients received adjuvant chemotherapy and 123 (63%) received whole breast radiation. Patients who received chemotherapy tended to have more adverse clinical and disease features (younger age,T1b, poor tumor grade; all p&lt;0.05). For the entire group, 5 year local recurrence-free survival was 96% and distant metastasis-free survival was 95%, with no difference in distant relapse rates between T1mic/T1a vs. T1b patients (94.5% vs 95.5%, p=0.81 )or by receipt of chemotherapy (95.9% vs 94.5%, p=0.63).

Conclusion: Excellent 5-year locoregional and distant control rates were achievable in patients with TNBC tumors ≤ 1.0 cm, 58% of whom received chemotherapy. These results identify a group of TNBC patients with favorable outcomes following early detection and multimodality treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-13.

Sclerodermatous graft-versus-host disease: clinical spectrum and therapeutic challenges

Sclerodermatous graft-versus-host disease (GVHD) is a rare complication of bone marrow transplantation. While GVHD is often associated with the beneficial graft vs. tumour effect, it also contributes towards significant morbidity and mortality. No reliably effective treatment has yet been established. We present 10 patients with haematological malignancies who underwent an allogeneic stem cell transplant and developed sclerodermatous GVHD. Donor lymphocyte infusion administered for relapse or reducing donor T-cell chimerism was a known trigger for sclerodermatous GVHD in four of the patients. Treatment with immunosuppressants, psoralen plus ultraviolet A (PUVA) and extracorporeal photopheresis has been largely unsuccessful in their management. Intensive immunosuppression including the use of anti-CD20 monoclonal antibody may have contributed to relapse of leukaemia in one patient 10 years after her transplant. Sclerodermatous GVHD may occur without a preceding lichenoid stage. Clinical heterogeneity is common, although sclerodermatous GVHD has a predilection for the limbs. Treatment options are largely unsatisfactory if conventional immunosuppression fails. PUVA may give some symptomatic benefit and extracorporeal photopheresis seems to be less efficacious than previously published work suggests.

Immune tolerance therapy for haemophilia

The development of anti-factor VIII and anti-factor IX allo-antibodies in haemophilia A and B, respectively, remains a serious complication of treatment for these two X-linked haemostatic disorders, with major clinical and economic consequences. Treatment of this potentially fatal complication remains one of the greatest challenges facing haematologists at the beginning of the 21st century. Immune tolerance induction (ITI) therapy has been generally accepted as the best available treatment, extinguishing the inhibitor and permitting a resumption of standard dosing schedules. Although there have been several established protocols for ITI therapy developed over the last quarter century, the optimal scheme in terms of safety, clinical efficacy and pharmacoeconomic considerations has yet to be determined.

PvuII polymorphisms of the estrogen receptor alpha and bone mineral density in healthy southern Chinese women

The association between PvuII polymorphisms of the estrogen receptor alpha (ERalpha) gene and total as well as regional bone mineral density (BMD) in healthy Chinese women (n = 182) was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), where P indicated the absence and p the presence of PvuII restriction sites. Subjects with PP genotype had significantly higher BMD at the thoracic spine and ribs (both P < 0.05) when compared with those with Pp and pp genotypes. Although PP genotype had slightly higher BMD values at the lumbar spine L2-L4 region and hip by 8% and 7%, respectively, the results failed to reach statistical significance. After adjusting for age, height, weight, and years since menopause, PP genotype had higher BMD at the left (P < 0.02) and right (P < 0.05) rib region but not at the thoracic spine (P = 0.056). Analyzing the premenopausal subjects alone (n = 64) revealed that subjects with PP genotype had higher adjusted BMD at the right rib region (P < 0.05). When only the postmenopausal women (n = 118) were analyzed, the adjusted BMD of the PP genotype at the thoracic spine was significantly higher (P < 0.05) than the other two groups. In conclusion, estrogen receptor gene has a role in determining bone mass but the clinical impact on its own is probably small.

Idiopathic hyperammonaemia syndrome following allogeneic peripheral blood progenitor cell transplantation (allo-PBPCT)

An idiopathic hyperammonaemia syndrome has been reported in, and following chemotherapy for, various haematological malignancies as well as following bone marrow transplantation. It should be considered in the differential diagnosis of any neurological deterioration, and we describe a further case associated with an allogeneic peripheral blood progenitor cell transplant (allo-PBPCT).

Clinical presentation of herpes zoster in a Singapore hospital

BACKGROUND

There is a direct correlation between increasing age and incidence of herpes zoster. There is an increased risk of complications in the elderly and the immunocompromised.

OBJECTIVE

To study the clinical epidemiology of hospitalised patients with herpes zoster.

METHODS

Medical records of all patients hospitalised with zoster were respectively analysed.

RESULTS

Sixty-seven patients (3% of total admissions) were studied. There were 35 males and 32 females with a mean age of 50.35 +/- 21.71. There was an increased proportion of older patients in the study cohort. Nineteen patients (28.4%) were immunocompromised with malignancy occurring in 9 patients. Thirteen had been on cytotoxic and/or steroid therapy. The commonest symptoms were rash, pain and fever. Eighty-five percent of the patients had complications (bacterial super-infection in (61%), dissemination (31%), ocular involvement (5%) and post-herpetic neuralgia (13.4%). There was an increasing frequency of duration of pain with increasing age in the patients with post-herpetic neuralgia. Forty-three patients were treated with acyclovir. The median time to healing of lesions was 11 days. The 41 patients with bacterial super-infection received antibiotics with median time to healing of 12 days.

CONCLUSION

Increasing age and immunocompromised state appear to be risk factors for developing herpes zoster in hospitalised patients.

Strong association of HLA BW46 with juvenile onset myasthenia gravis in Hong Kong Chinese

The HLA antigen distribution and thyroid autoantibody status of 27 Chinese children in Hong Kong with juvenile onset myasthenia gravis have been compared with 110 healthy university students from the same population. Twenty-four of the patients had ocular myasthenia. There was a significantly increased prevalence of HLA BW46 in the patients compared with controls (67% vs 26.4%, p less than 0.005) indicating that BW46 confers a relative risk of 5.6 for juvenile onset myasthenia gravis in Chinese children. The increased prevalence of BW46 was not associated with thyroid autoimmunity in the patients although the antigen is known to be associated with thyrotoxicosis in Chinese. The possibility that BW46 confers protection against the development of acetyl-choline receptor antibodies in Chinese patients is discussed. One patient had the Caucasian antigen B8 and the question whether defective immune response genes were introduced into the Chinese through Caucasian admixture is raised.