Change in the Use of Fractionation in Radiotherapy Used for Early Breast Cancer at the Start of the COVID-19 Pandemic: A Population-Based Cohort Study of Older Women in England and Wales

Aims

Adjuvant radiotherapy is recommended for most patients with early breast cancer (EBC) receiving breast-conserving surgery and those at moderate/high risk of recurrence treated by mastectomy. During the first wave of COVID-19 in England and Wales, there was rapid dissemination of randomised controlled trial-based evidence showing non-inferiority for five-fraction ultra-hypofractionated radiotherapy (HFRT) regimens compared with standard moderate-HFRT, with guidance recommending the use of five-fraction HFRT for eligible patients. We evaluated the uptake of this recommendation in clinical practice as part of the National Audit of Breast Cancer in Older Patients (NABCOP).

Materials and methods

Women aged ≥50 years who underwent surgery for EBC from January 2019 to July 2020 were identified from the Rapid Cancer Registration Dataset for England and from Wales Cancer Network data. Radiotherapy details were from linked national Radiotherapy Datasets. Multivariate mixed-effects logistic regression models were used to assess characteristics influential in the use of ultra-HFRT.

Results

Among 35 561 women having surgery for EBC, 71% received postoperative radiotherapy. Receipt of 26 Gy in five fractions (26Gy5F) increased from <1% in February 2020 to 70% in April 2020. Regional variation in the use of 26Gy5F during April to July 2020 was similar by age, ranging from 49 to 87% among women aged ≥70 years. Use of 26Gy5F was characterised by no known nodal involvement, no comorbidities and initial breast-conserving surgery. Of those patients receiving radiotherapy to the breast/chest wall, 85% had 26Gy5F; 23% had 26Gy5F if radiotherapy included regional nodes. Among 5139 women receiving postoperative radiotherapy from April to July 2020, nodal involvement, overall stage, type of surgery, time from diagnosis to start of radiotherapy were independently associated with fractionation choice.

Conclusions

There was a striking increase in the use of 26Gy5F dose fractionation regimens for EBC, among women aged ≥50 years, within a month of guidance published at the start of the COVID-19 pandemic in England and Wales.

Abstract P5-04-05: Targeting the pH regulatory mechanisms of breast cancer cells

Background:

The abnormal regulation of H+ ions, leading to a reversed pH gradient in tumor cells in comparison to normal cells, is considered to be one of the hallmarks of cancer. This feature, however, has yet to be exploited as a therapeutic target. The aim of this study was to assess whether targeting proteins (CAIX, NHE1 and V-ATPase) that permit hypoxic cancer cell adaptation to acidosis in the tumor microenvironment can produce an effective therapeutic response in breast cancer, using 2D and 3D models.

Method:

Western blotting and gene expression analysis were performed on MCF-7, MDA-MB-231 and HBL-100 cancer cells to assess target protein expression in differing O2 conditions in 2D, while IHC was used to measure protein levels in 3D using multicellular tumor spheroids. Sulforhodamine B assays were executed to analyze the effects of inhibitors targeting CAIX, NHE1 and V-ATPase on breast cancer cell proliferation in 2D. 3D invasion assays were performed with MDA-MB-231 spheroids and explant tissue derived from human patients to see if CAIX inhibition had any effect on cancer cell invasion. An MDA-MB-231 xenograft model was used to investigate the effects of CAIX inhibition in vivo. Clonogenic assays were performed with MDA-MB-231 spheroids to evaluate whether any of the drugs combined effectively with irradiation.

Results:

2D and 3D expression analysis showed that CAIX levels were extremely responsive to changes in O2 conditions in each of the cell lines, with HBL100 cells exhibiting the largest changes in both mRNA (42-fold increase) and protein (78-fold increase) levels at low (0.5%) O2 concentrations. NHE1 and V-ATPase mRNA/protein levels were, however, much more consistently expressed across the cell lines in different O2 conditions. Drugs targeting CAIX, NHE1 and V-ATPase had anti-proliferative effects on the breast cancer cells in 2D. Normoxic cancer cells were the most sensitive to drug treatment, acute hypoxic cancer cells showed increased resistance to the anti-proliferative effects of these drugs, while chronic hypoxic cells had IC50 values more similar to the normoxic cells. The results for the CAIX inhibitor were unexpected, as we had predicted that the increased levels of CAIX in the acute hypoxic cells would make them more sensitive to treatment. CAIX inhibition did, however, significantly reduce the invasion of cancer cells from both MDA-MB-231 spheroids (p≤0.01) and explant tissue (p≤0.001). Targeting pH regulation was also shown to have an effect in vivo on MDA-MB-231 xenografts, with CAIX inhibition significantly reducing the growth (p≤0.05) and proliferation (p≤0.05) of tumors within mice. Finally, clonogenic assays showed that drugs targeting both CAIX and NHE1 led to a significant reduction in colony number when combined with radiation (p≤0.05), compared to either drug individually or radiation treatment alone.

Conclusions:

This study shows that drugs targeting pH regulation molecules have potential in the treatment of breast cancer. This is highlighted by their ability to affect the proliferation and invasion of breast cancer cells, along with their ability to be combined with radiation. Of the 3 pH regulatory molecules, CAIX represents the target with the most promise.

Citation Format: Meehan J, Ward C, Jarman E, Xintaropoulou C, Martinez-Perez C, Turnbull A, Supuran C, Dixon M, Kunkler I, Langdon SP. Targeting the pH regulatory mechanisms of breast cancer cells. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-05.

Patterns of practice of regional nodal irradiation in breast cancer: results of the European Organization for Research and Treatment of Cancer (EORTC) NOdal Radiotherapy (NORA) survey

BACKGROUND

Predicting outcome of breast cancer (BC) patients based on sentinel lymph node (SLN) status without axillary lymph node dissection (ALND) is an area of uncertainty. It influences the decision-making for regional nodal irradiation (RNI). The aim of the NORA (NOdal RAdiotherapy) survey was to examine the patterns of RNI.

METHODS

A web-questionnaire, including several clinical scenarios, was distributed to 88 EORTC-affiliated centers. Responses were received between July 2013 and January 2014.

RESULTS

A total of 84 responses were analyzed. While three-dimensional (3D) radiotherapy (RT) planning is carried out in 81 (96%) centers, nodal areas are delineated in only 51 (61%) centers. Only 14 (17%) centers routinely link internal mammary chain (IMC) and supraclavicular node (SCN) RT indications. In patients undergoing total mastectomy (TM) with ALND, SCN-RT is recommend by 5 (6%), 53 (63%) and 51 (61%) centers for patients with pN0(i+), pN(mi) and pN1, respectively. Extra-capsular extension (ECE) is the main factor influencing decision-making RNI after breast conserving surgery (BCS) and TM. After primary systemic therapy (PST), 49 (58%) centers take into account nodal fibrotic changes in ypN0 patients for RNI indications. In ypN0 patients with inner/central tumors, 23 (27%) centers indicate SCN-RT and IMC-RT. In ypN1 patients, SCN-RT is delivered by less than half of the centers in patients with ypN(i+) and ypN(mi). Twenty-one (25%) of the centers recommend ALN-RT in patients with ypN(mi) or 1-2N+ after ALND. Seventy-five (90%) centers state that age is not considered a limiting factor for RNI.

CONCLUSION

The NORA survey is unique in evaluating the impact of SLNB/ALND status on adjuvant RNI decision-making and volumes after BCS/TM with or without PST. ALN-RT is often indicated in pN1 patients, particularly in the case of ECE. Besides the ongoing NSABP-B51/RTOG and ALLIANCE trials, NORA could help to design future specific RNI trials in the SLNB era without ALND in patients receiving or not PST.

Funding UK cancer care: time for a level playing field?

Improving cancer survival rates is a UK priority and equity of access to high quality cancer irrespective of geography is a key principle. Surgery, radiation therapy and systemic therapy remain the cornerstone of the multidisciplinary management of cancer. However, costs of cancer care continue to escalate. A recent review (1) estimated the global costs of cancer care caused by death and disability as US $895 billion (excluding indirect medical costs and based on 2008 figures). Approximately 49% of patients are cured by surgery, 40% by radiotherapy alone or in combination with other treatments and 11% by systemic therapy. With > 90,000 patients per annum treated with curative intent by radiotherapy in the UK, one would anticipate that access to modern radiotherapy techniques would have a high priority. However, there are substantial differences in the NHS uptake of new anti-cancer agents and advanced radiation technologies. In this article, these differences are explored and recommendations made for addressing them.

UK guidance document: treatment of metastatic breast cancer

Although there have been major improvements in the management of breast cancer, with a rapidly falling death rate despite an increasing incidence of the disease, metastatic breast cancer remains common and the cause of death in nearly 12 000 women annually in the UK. Numerous treatment options are available that either target the tumour or reduce the complications of the disease. Clinical decision making depends on knowledge of the extent and biology of the disease and available drug options, an understanding of the functional status, and also the wishes and expectations of the individual patient. In addition, the organisation of services and support of the patient are essential components of high-quality care. The National Institute for Health and Clinical Excellence (NICE) has produced guidelines for the treatment of advanced breast cancer, which in some areas have perhaps failed to appreciate the complexity of patient management. This guidance document aims to provide succinct practical advice on the treatment of metastatic breast cancer, highlight some limitations of the NICE guidelines, and provide suggestions for management where available data are limited.

The treatment of early breast cancer in women over the age of 70

One third of all breast cancers are diagnosed in women aged 70 or over. Older women are a heterogeneous population who are under-represented in clinical trials, and as a result uncertainty can exist as to what represents optimal treatment. This minireview, from an international authorship, summarises the existing evidence surrounding the management of early breast cancer in women aged 70 and over. The use of primary surgery and endocrine therapy, and adjuvant chemotherapy, radiotherapy, endocrine therapy and trastuzumab are discussed. Reference is made to ongoing clinical trials in this area and areas of controversy are highlighted.

Expression Levels of Co-Regulators in Early Breast Cancer

Introduction: The p160 (SRC) family of estrogen receptor (ER) co-activators have important implications in tamoxifen resistance. The SRC family play a central role in ER mediated transcription. There are three family members; SRC-1, SRC-2 and AIB1. AIB1 is amplified in 5-10% of human breast cancers. SRC-1 expression is associated with HER2 expression, increased risk of recurrence and insensitivity to endocrine treatment. Co-factors interact with the ER and basal transcriptional machine to activate or repress ER-mediated transcription. To investigate the role of ER and its co-factors in breast cancer we have carried out quantitative RT-PCR (qRT-PCR) to measure the relative expression of ERa and its co-factors.Methods: In this study we examined patients which were untreated or treated with chemotherapy or hormonal therapy following breast conservation surgery. RNA was extracted from 340 early breast cancer specimens from the Edinburgh Breast Conserving Surgery cohort (BCS). The BCS is a fully documented consectutive cohort of breast cancers treated by conservation surgery, axillary node sampling or clearance, and whole breast radiotherapy between 1981-1998. Clinico-pathological features and complete follow up (duration &gt;10 years) is available for this cohort. qRT-PCR was carried out using primers for ER, SRC-1, SRC-2, AIB1, NCoR1 and SMRT.Results: This study demonstrated SRC-1 expression to be negatively correlated with both SRC-2 and AIB1 expression. SRC-1 expression was also negatively correlated with the co-repressors NCoR1 and SMRT expression. There was a strong correlation between the co-repressors, NCoR1 and SMRT and the co-activators SRC-2 and AIB1. Relapse-free survival (RFS) was estimated using Kaplan-Meier curves. Patients who had high expression of all three co-activators had reduced relapse-free survival (HR: 2.15 95%C.I. 1.175-3.921, p=0.01). No significant association was noted with overall survival. Exploratory subgroup analysis was under powered and showed no significant association with outcome.Conclusion: In conclusion, our study of expression levels of ER and its cofactors by quantitative RT-PCR in breast cancer samples revealed a correlation between the co-factors and co-repressors. These findings would suggest that ER and cofactors may play a synergistic role in the development and progression of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2127.

The Expression of Insulin-Like Growth Factor-1 Receptor (IGF-1R) in Early Breast Cancer

Background: The insulin-like growth factor-1 receptor (IGF-1R) is expressed in normal breast epithelial cells and breast carcinomas. A number of studies have examined the over-expression of IGF-1R in breast cancer with the range of between 39% to 93%. However, many of these studies were carried out using ELISAs, radioimmunoassay with small patient cohorts. Phosphorylation of IGF-1R results in the activation of the MAPK and PI3K/Akt pathway. Activation of the PI3K/Akt pathway under the influence of IGF-1R plays an important role in maintaining the proliferation of breast cancer cells that are resistant to gefitnib, trastuzumab or chemoradiotherapy in vitro and in vivo. In the present study, we examined the expression of IGF-1R in early breast cancer and investigated the clinicopathological implications using immunohistochemistry and FISH.Methods: TMAs from a consecutive series (1981-98) of 1,812 women managed by wide local excision and postoperative radiotherapy (45Gy in 20-25 fractions) were collected following appropriate ethical review. Of 1686 cases stained, 198 received no adjuvant hormonal or chemotherapy, 1106 received tamoxifen only as adjuvant therapy and 144 received a combination of hormonal and chemotherapy. Median age at diagnosis was 56, 72% were post-menopausal, 23.9% node positive, median size was 1.5 cm. Samples were stained, using triplicate 0.6mm2 TMA cores for IGF-1R.Results: FISH for IGF1R gene amplification was successful in 343/408 cases (84%). Only 7 cases of IGF1R amplification were observed (2%). IGF1R expression was successfully evaluated in 1597 of 1686 (94.7%) cases. High levels of IGF-1R expression was weakly associated with tumour ER-a (correlation coefficient, 0.108; p=2.2 x 10-5) and PgR levels (correlation coefficient 0.162; p=1.86x10-10) and inversely correlated with EGFR expression (correlation coefficient -0.189; p=6.33x10-6). No association was noted between IGF1R expression and other molecular or clinical markers, such as tumour size. There was a trend for over-expression of IGF-1R to link with increased distant relapse free survival, particularly in ER positive breast cancers. This trend is time dependent, such that no difference in outcome is observed at 15 years.Conclusions: We have demonstrated in a large cohort of patients that IGF-1R gene amplification is a rare event, and over-expression is weakly associated with good prognostic features (ERa and PgR, lack of EGFR and better outcome).

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2128.

Exemestane in metastatic breast cancer: Effective therapy after third-generation non-steroidal aromatase inhibitor failure

Exemestane is a potent steroidal aromatase inhibitor (AI) with activity in post-menopausal women with metastatic breast cancer, with a reported clinical benefit (CB) rate of 24.3% after prior AI therapy. Data on 114 patients (112 female, 2 male) were obtained retrospectively at two cancer centres. Sixty-five percent of patients were confirmed as oestrogen receptor (ER) positive. All patients had received prior third-generation AI therapy. Responses were seen in 5% and the overall CB rate (CR+PR+SD24 weeks) was 46%. Median PFS and OS were 18 and 61 weeks, respectively. In patients with visceral disease, the CBR was 33%. Patients with known ER-positive disease had a CBR of 47%, and a median TTP of 19 weeks. No benefit was seen in patients with known ER-negative disease. Survival was better in those with CB (median survival not reached in those with CB, 28 weeks in those without CB P<0.0001). Efficacy persisted in those patients who had received 3 prior lines of hormonal therapy, including adjuvant treatment. These data confirm exemestane to be an effective therapy after third-generation non-steroidal AI in post-menopausal ER-positive metastatic breast cancer, including visceral disease.

Don't wait for a sensory level--listen to the symptoms: a prospective audit of the delays in diagnosis of malignant cord compression

AIM

To report details concerning symptoms (especially pain) preceding the development of malignant cord compression (MCC); delays between onset/reporting of symptoms and confirmed diagnosis of MCC; accuracy of investigations carried out.

METHODS

A prospective observational study examined the diagnosis, management and outcome of 319 patients diagnosed with MCC at three Scottish cancer centres between January 1998-April 1999. The process was considered from the perspectives of the patient, the GP and the hospital doctor.

RESULTS

At diagnosis, most patients (82%) were either unable to walk or only able to do so with help. Pain was reported by nearly all patients interviewed (94%) and had been present for approximately 3 months (median=90 days). It was severe in 84% of cases, with the distribution and characteristics of nerve root pain in 79%. The site of pain did not correspond to the site of compression. Where reported, weakness and/or sensory problems had been noticed by the patient for some time before diagnosis (median intervals 20 and 12 days, respectively). Most patients reported early symptoms to their General Practitioner (GP) and diagnosis was established, following referral and investigation, approximately 2 months (median=66 days) later.

CONCLUSION

Patients who develop spinal metastases are at risk of irreversible spinal cord damage. Weakness and sensory abnormalities are reported late and identified even later, despite patients having reported pain for a considerable time. Patients with cancer who describe severe back or spinal nerve root pain need urgent assessment on the basis of their symptoms, as signs may occur too late. Plain films and bone scans requested for patients in this audit predicted accurately the level of compression in only 21% and 19% of cases, respectively. The only accurate investigation to establish the presence and site of a compressive lesion is magnetic resonance imaging (MRI). A referral guideline based on suspicious symptoms in addition to suspicious signs is suggested.

Imaging features of leptomeningeal metastases

AIMS

To assess the range of appearances, and accuracy of various methods of diagnosing leptomeningeal metastases.

MATERIALS AND METHODS

In a retrospective study, the notes and imaging of all patients with a radiological and/or CSF cytological diagnosis of leptomeningeal metastasis (LM) were identified, and assessed for the following: age and sex, primary tumour type, presenting symptoms, initial radiological and cytological diagnosis, radiological appearances and length of survival following diagnosis. Discordance between the CSF cytology and radiological diagnosis of LM was also noted.

RESULTS

41 positive cases (36 female) of LM were identified over a 2.7 year period (diagnosis based on: imaging only--19 cases, cytology only--6, both--16 cases). The average age was 48 years, and the most frequent primary tumour was breast carcinoma (27/41). Two thirds of patients presented with at least one cranial or spinal nerve palsy. Where performed, contrast-enhanced CT was normal in 40% (10/25), with LM mistaken for parenchymal disease in a further 24% (6/25). CSF cytology was positive in 85% (22/26). Gadolinium-enhanced MRI was positive in all cases where it was performed (25/25). Pial enhancement and nodularity was the commonest finding (67%), but other manifestations included nodular disease, neural enhancement and white matter changes. Prognosis was uniformly poor.

CONCLUSION

Leptomeningeal metastatic disease has a poor prognosis, and treatment regimen may differ from those of parenchymal CNS metastases. CT is normal or misleading in two thirds of patients, and CSF cytology may also be negative. Gadolinium-enhanced T1-weighted MRI complements CSF cytology, and is the investigation of choice in patients with a non-haematological primary tumour and suspected LM.

Modern brachytherapy: current state and future prospects

This article reviews the current trends and future developments in brachytherapy. Established techniques including interstitial and high-dose rate brachytherapy are discussed with particular reference to lung, oesophageal, cervical and endometrial cancer. Intra-operative high-dose rate brachytherapy and other new techniques are also mentioned.

High-dose chemotherapy supported by peripheral blood progenitor cells in poor prognosis metastatic breast cancer--phase I/II study. Edinburgh Breast Group

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

The use of single fraction Leksell stereotactic radiosurgery in the treatment of uveal melanoma

Fourteen patients with posterior uveal melanomas were treated using single fraction stereotactic radiosurgery. In each case a dose of 70 Gy was administered to the periphery of the tumour. Regression of the tumour has been observed in 13 patients, whilst the lesion has remained unchanged in one patient. The visual acuity has deteriorated in all 14 patients. Significant radiation induced adverse reactions were noted in 13 patients and include; retinopathy, optic neuropathy, rubeosis iridis, and secondary glaucoma. Two patients have required enucleation because of intractable rubeotic glaucoma. One patient has died from proven metastases. Although stereotactic radiosurgery appears to be a practical and effective method of treating uveal melanomas, its usefulness is limited by a high incidence of radiation induced adverse reactions. Further work is required to refine the current treatment protocol and establish an optimal prescription dose.

A glossary for reporting complications of treatment in gynecological cancers

Reporting and scoring treatment complications in gynecological cancers is difficult because of the variety of normal tissues, anatomical structures and treatment disciplines involved, making it impossible to compare series of patients treated in different institutions even with the same strategy. An international group of experts (gynecologists, radiotherapists and surgeons) developed a multidisciplinary database to identify, score and report early and late normal tissue damage regardless of treatment strategy. The principles involve: (1) The identification of relevant organs and tissues; (2) An accurate definition of the type and score of each complication; (3) Reporting combinations of complications of various degrees; (4) A computerized format for data acquisition, update and retrieval. In the present version, the "Glossary" describes five degrees of increasing severity (0 to 4) in 14 organs and/or normal tissues. The rationale of the glossary leaves it open for as yet undescribed types of complications. This paper contains the definition and scoring for each type of complication, general guidelines for their use.

Radiation therapy in the treatment of early glottic carcinoma: the experience of Villejuif

A retrospective analysis of 197 early glottic carcinoma treated with small field irradiation to a dose of 65 Gy is presented. The 5-year survival rate was 77.3%. Thirty-eight local failures have been observed, and the 5-year local control rate was 85.7%. Suspicion of extra glottic extension was the main prognostic factor. Final local control rate, taking into account the salvage treatment, was 90% at 5 years. Excellent functional results were observed.