Local hero: A phase II study of local therapy only (stereotactic radiosurgery and / or surgery) for treatment of up to five brain metastases from HER2+ breast cancer. (TROG study 16.02)

Introduction, A decade ago, stereotactic radiosurgery (SRS) without whole brain radiotherapy (WBRT) was emerging as preferred treatment for oligometastatic brain metastases. Studies of cavity SRS after neurosurgery were underway. Data specific to metastatic HER2 breast cancer (MHBC), describing intracranial, systemic and survival outcomes without WBRT, were lacking. A Phase II study was designed to address this gap. Method, Adults with MHBC, performance status 0-2, ≤ five BrM, receiving/planned to receive HER2-targeted therapy were eligible. Exclusions included leptomeningeal disease and prior WBRT. Neurosurgery allowed ≤6 weeks before registration and required for BrM >4 cm. Primary endpoint was 12-month requirement for WBRT. Secondary endpoints; freedom from (FF-) local failure (LF), distant brain failure (DBF), extracranial disease failure (ECDF), overall survival (OS), cause of death, mini-mental state examination (MMSE), adverse events (AE). Results, Twenty-five patients accrued Decembers 2016-2020. The study closed early after slow accrual. Thirty-seven BrM and four cavities received SRS. Four cavities and five BrM were observed. At 12 months: one patient required WBRT (FF-WBRT 95 %, 95 % CI 72-99), FFLF 91 % (95 % CI 69-98), FFDBF 57 % (95 % CI 34-74), FFECDF 64 % (95 % CI 45-84), OS 96 % (95 % CI 74-99). Two grade 3 AE occurred. MMSE was abnormal for 3/24 patients at baseline and 1/17 at 12 months. Conclusion, At 12 months, SRS and/or neurosurgery provided good control with low toxicity. WBRT was not required in 95 % of cases. This small study supports the practice change from WBRT to local therapies for MHBC BrM.

Impact on Pulmonary Function in a Randomized Trial of Single-Fraction and Multifraction Stereotactic Body Radiation Therapy for Pulmonary Oligometastatic Disease: An Analysis of TROG 13.01 (SAFRON II)

PURPOSE

The TROG 13.01 (SAFRON II) trial was a phase 2 multicenter trial comparing single-fraction (SF) and multifraction (MF) stereotactic body radiation therapy. Patients with 1 to 3 peripheral pulmonary oligometastases were randomized 1:1 between 28 Gy in 1 fraction and 48 Gy in 4 fractions. There were no differences between arms in efficacy or toxicity. We performed an analysis to assess changes in pulmonary function tests (PFTs) between arms over time and assessed the effect of the number and total volume of targets on PFT change over time.

METHODS AND MATERIALS

A linear mixed model was used to describe the PFTs by treatment arm over time. The effect of number and volume of targets on PFTs at 6 and 12 months was assessed by a simple linear model.

RESULTS

Ninety patients were randomized; 87 were treated for 133 pulmonary oligometastases. Forty-four were randomized to the SF arm and 43 to the MF arm. There were no differences in absolute or relative PFT measures of forced expiratory volume in 1 second (FEV1), diffusing capacity of the lungs for carbon monoxide (DLCO), or forced vital capacity (FVC) between the 2 arms. At 12 months, there was a reduction in absolute DLCO from baseline (-1.7 mL/min/mm Hg [95% CI, -2.5 to -1.0]), relative DLCO (-5.5% [95% CI, -8.4% to -2.6%]), absolute FEV1 (-0.17 L [95% CI, -0.23 to -0.11]), and absolute FVC (-0.20 L [95% CI, -0.27 to -0.13]). In patients with multiple pulmonary targets, increase in target number (per lesion) was associated with a reduction in the absolute FEV1 at 6 months of -0.10 L (95% CI, -0.18 to -0.03; P = .007), FEV1 at 12 months of -0.10 L (95% CI, -0.20 to -0.01; P = .04), FVC at 6 months of -0.11 L (95% CI, -0.20 to -0.03; P = .014), and FVC at 24 months of -0.13 L (95% CI, -0.25 to -0.01; P = .036). Reduction in FEV1 was also seen per 10-mL increase in PTV at 12 months (-0.03 L [95% CI, -0.06 to -0.00], P = .036). The number of targets and PTV were not associated with DLCO.

CONCLUSIONS

Treating multiple targets resulted in increased loss of FEV1 and FVC but not DLCO. There were no significant differences in PFT decline between SF and MF stereotactic body radiation therapy.

Real-World Experience of Immune-Checkpoint Inhibitors in Older Patients with Advanced Cutaneous Squamous Cell Carcinoma

BACKGROUND

Older patients are often underrepresented in clinical trials owing to exclusionary comorbidities, which are more common with age. Chemotherapy is poorly tolerated in older comorbid advanced cutaneous squamous cell carcinoma (CSCC) patients; however, little is known on the efficacy and tolerability of immune-checkpoint inhibitors (ICIs) in this population. To our knowledge, this is the largest dedicated report on a cohort of older patients with advanced CSCC treated with immunotherapy to date.

OBJECTIVE

The aim was to report outcomes of ICI use in a real-world older cohort with advanced CSCC.

PATIENTS AND METHODS

A single-centre retrospective audit of all patients treated via an access scheme providing ICIs to patients with advanced CSCC was conducted. Participants were ≥ 70 years of age and had advanced CSCC not amenable to curative surgery or radiotherapy. Best overall response rate (ORR), 12-month overall survival (OS) and progression-free survival (PFS), and toxicity rates were assessed.

RESULTS

A total of 53 patients were analysed. The median age was 81.8 years (range 70.1-96.8); 81% were male; 34% were immunocompromised; and 34% had an Eastern Cooperative Oncology Group (ECOG) performance status score of ≥ 2. The ORR was 57%, and 12-month OS and PFS were 63% (95% confidence interval [CI] 44-78) and 41% (95% CI 25-57), respectively. Thirty-two per cent developed an immune-related adverse event (irAE), but only two patients experienced a grade 3 irAE, with no treatment-related deaths. Higher ECOG score was associated with worse OS and PFS. No significant association was identified for increasing age, sex, Charlson Comorbidity Index score, or immunocompromised status.

CONCLUSIONS

ICIs have demonstrated efficacy and have an acceptable safety profile among older patients with advanced CSCC, with comparable efficacy to what has been demonstrated in current clinical trials.

Characterising B cell expression and prognostic significance in human papillomavirus positive oropharyngeal cancer

OBJECTIVES

The incidence of human papillomavirus positive oropharyngeal cancer (HPV+OPC) is increasing, and new biomarkers are required to better define prognostic groups and guide treatment. Infiltrating T cells have been well studied in head and neck cancer, however the presence and role of B cells and tertiary lymphoid structures (TLS) in the tumor microenvironment has not, even though the interplay between T and B cells is increasingly being recognised.

MATERIALS AND METHODS

Using CD20 immunohistochemistry (IHC) to identify B cells and TLS in a cohort of 159 HPV + OPC patients, we semi-quantitatively scored abundance and location (intra-tumoral or stromal) and correlated findings with patient survival.

RESULTS

32% (51/157) of patients had high intra-tumoral (IT) abundance of CD20+ B cells (≥5%) and this was prognostic for improved overall survival (OS) with an adjusted hazard ratio (HR) of 0.2 (95 % CI 0.0-0.7, p = 0.014). We validated our results in an independent cohort comprising 171 HPV + OPC where 14% (23/171) were IT CD20+ high, again showing improved survival with an adjusted HR for OS of 0.2 (95 % CI 0.0-1.4, p = 0.003). Neither stromal abundance nor the presence of TLS were prognostic in either cohort. B cells were subtyped by multispectral IHC, identifying CD20+CD27+ cells, consistent with memory B cells, as the predominant subtype. Combined with validated biomarker CD103, a marker of tissue-resident memory T cells, IT CD20+ B cells abundance was able to prognostically stratify patients further.

CONCLUSIONS

CD20+ B cell abundance has the potential to be used as a biomarker to identify good and poor prognosis HPV + OPC patients.

Stereotactic ablative body radiotherapy for primary kidney cancer (TROG 15.03 FASTRACK II): a non-randomised phase 2 trial

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) is a novel non-invasive alternative for patients with primary renal cell cancer who do not undergo surgical resection. The FASTRACK II clinical trial investigated the efficacy of SABR for primary renal cell cancer in a phase 2 trial.

METHODS

This international, non-randomised, phase 2 study was conducted in seven centres in Australia and one centre in the Netherlands. Eligible patients aged 18 years or older had biopsy-confirmed diagnosis of primary renal cell cancer, with only a single lesion; were medically inoperable, were at high risk of complications from surgery, or declined surgery; and had an Eastern Cooperative Oncology Group performance status of 0-2. A multidisciplinary decision that active treatment was warranted was required. Key exclusion criteria were a pre-treatment estimated glomerular filtration rate of less than 30 mL/min per 1·73 m2, previous systemic therapies for renal cell cancer, previous high-dose radiotherapy to an overlapping region, tumours larger than 10 cm, and direct contact of the renal cell cancer with the bowel. Patients received either a single fraction SABR of 26 Gy for tumours 4 cm or less in maximum diameter, or 42 Gy in three fractions for tumours more than 4 cm to 10 cm in maximum diameter. The primary endpoint was local control, defined as no progression of the primary renal cell cancer, as evaluated by the investigator per Response Evaluation Criteria in Solid Tumours (version 1.1). Assuming a 1-year local control of 90%, the null hypothesis of 80% or less was considered not to be worthy of proceeding to a future randomised controlled trial. All patients who commenced trial treatment were included in the primary outcome analysis. This trial is registered with ClinicalTrials.gov, NCT02613819, and has completed accrual.

FINDINGS

Between July 28, 2016, and Feb 27, 2020, 70 patients were enrolled and initiated treatment. Median age was 77 years (IQR 70-82). Before enrolment, 49 (70%) of 70 patients had documented serial growth on initial surveillance imaging. 49 (70%) of 70 patients were male and 21 (30%) were female. Median tumour size was 4·6 cm (IQR 3·7-5·5). All patients enrolled had T1-T2a and N0-N1 disease. 23 patients received single-fraction SABR of 26 Gy and 47 received 42 Gy in three fractions. Median follow-up was 43 months (IQR 38-60). Local control at 12 months from treatment commencement was 100% (p<0·0001). Seven (10%) patients had grade 3 treatment-related adverse events, with no grade 4 adverse events observed. Grade 3 treatment-related adverse events were nausea and vomiting (three [4%] patients), abdominal, flank, or tumour pain (four [6%]), colonic obstruction (two [3%]), and diarrhoea (one [1%]). No treatment-related or cancer-related deaths occurred.

INTERPRETATION

To our knowledge, this is the first multicentre prospective clinical trial of non-surgical definitive therapy in patients with primary renal cell cancer. In a cohort with predominantly T1b or larger disease, SABR was an effective treatment strategy with no observed local failures or cancer-related deaths. We observed an acceptable side-effect profile and renal function after SABR. These outcomes support the design of a future randomised trial of SABR versus surgery for primary renal cell cancer.

FUNDING

Cancer Australia Priority-driven Collaborative Cancer Research Scheme.

Administering [177Lu]Lu-PSMA-617 Prior to Radical Prostatectomy in Men with High-risk Localised Prostate Cancer (LuTectomy): A Single-centre, Single-arm, Phase 1/2 Study

BACKGROUND

High-risk localised prostate cancer (HRCaP) has high rates of biochemical recurrence; [177Lu]Lu-PSMA-617 is effective in men with advanced prostate cancer.

OBJECTIVE

To investigate the dosimetry, safety, and efficacy of upfront [177Lu]Lu-PSMA-617 in men with HRCaP prior to robotic radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

In this single-arm, phase I/II trial, we recruited men with HRCaP (any of prostate-specific antigen [PSA] >20 ng/ml, International Society of Urological Pathology (ISUP) grade group [GG] 3-5, and ≥cT2c), with high tumour uptake on [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography (PSMA PET/CT), and scheduled for RP.

INTERVENTION

Cohort A (n = 10) received one cycle and cohort B (n = 10) received two cycles of [177Lu]Lu-PSMA-617 (5 GBq) followed by surgery 6 weeks later.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was tumour radiation absorbed dose. Adverse events (AEs; Common Terminology Criteria for Adverse Events (CTCAE) version 5.0), surgical safety (Clavien-Dindo), imaging, and biochemical responses were evaluated (ClinicalTrials.gov: NCT04430192).

RESULTS AND LIMITATIONS

Between May 29, 2020 and April 28, 2022, 20 patients were enrolled. The median PSA was 18 ng/ml (interquartile range [IQR] 11-35), Eighteen (90%) had GG ≥3, and six (30%) had N1 disease. The median (IQR) highest tumour radiation absorbed dose after cycle 1 for all lesions was 35.5 Gy (19.5-50.1), with 19.6 Gy (11.3-48.4) delivered to the prostate. Five patients received radiation to lymph nodes. Nine (45%) patients achieved >50% PSA decline. The most common AEs related to [177Lu]Lu-PSMA-617 were grade 1 fatigue in eight (40%), nausea in seven (35%), dry mouth in six (30%), and thrombocytopenia in four (20%) patients. No grade 3/4 toxicities or Clavien 3-5 complications occurred. Limitations include small a sample size.

CONCLUSIONS

In men with HRCaP and high prostate-specific membrane antigen (PSMA) expression, [177Lu]Lu-PSMA-617 delivered high levels of targeted radiation doses with few toxicities and without compromising surgical safety. Further studies of [177Lu]Lu-PSMA-617 in this population are worthwhile to determine whether meaningful long-term oncological benefits can be demonstrated.

PATIENT SUMMARY

In this study, we demonstrate that up to two cycles of [177Lu]Lu-PSMA-617 given prior to radical prostatectomy in patients with high-risk localised prostate cancer are safe and deliver targeted doses of radiation to tumour-affected tissues. It is tolerated well with minimal treatment-related adverse events, and surgery is safe with a low rate of complications. Activity measured through PSA reduction, repeat PSMA PET/CT, and histological response is promising.

Immune checkpoint inhibitor therapy for advanced cutaneous squamous cell carcinoma in Australia: a retrospective real world cohort study

OBJECTIVES

To review the outcomes of immune checkpoint inhibitor (ICI) treatment of advanced cutaneous squamous cell carcinoma (CSCC) outside clinical trials.

STUDY DESIGN

Retrospective observational study; review of patient records in fifteen Australian institutions.

SETTING, PARTICIPANTS

All Australian adults with locally advanced or metastatic CSCC not amenable to curative surgery or radiotherapy treated with ICIs, 5 May 2017 - 23 May 2022, through a cemiplimab compassionate access scheme (Therapeutic Goods Administration Special Access Scheme) or who personally covered the cost of pembrolizumab prior to the start of the access scheme.

MAIN OUTCOME MEASURES

Best overall response rate (ORR) according to standardised assessment criteria using the hierarchy: Response Evaluation Criteria in Solid Tumors (RECIST 1.1), the modified World Health Organization clinical response criteria, and the Positron Emission Tomography Response Criteria (PERCIST 1.0); overall and progression-free survival.

RESULTS

A total of 286 people with advanced CSCC received ICI therapy during May 2017 - May 2022 (cemiplimab, 270; pembrolizumab, 16). Their median age was 75.2 years (range, 39.3-97.5 years) and 232 were men (81%); median follow-up time was 12.2 months (interquartile range, 5.5-20.5 months). Eighty-eight people (31%) were immunocompromised, 27 had autoimmune disease, and 59 of 277 (21%) had ECOG performance scores of 2 or 3. The ORR was 60% (166 of 278 evaluable patients): complete responses were recorded for 74 (27%) and partial responses for 92 patients (33%). Twelve-month overall survival was 78% (95% confidence interval [CI], 72-83%); progression-free survival was 65% (95% CI, 58-70%). Poorer ECOG performance status was associated with poorer overall survival (per unit: adjusted hazard ratio [aHR], 3.0; 95% CI, 2.0-4.3) and progression-free survival (aHR, 2.4; 95% CI, 1.8-3.3), as was being immunocompromised (overall: aHR, 1.8; 95% CI, 1.1-3.0; progression-free: aHR, 1.8; 95% CI, 1.2-2.7). Fifty-five people (19%) reported immune-related adverse events of grade 2 or higher; there were no treatment-related deaths.

CONCLUSION

In our retrospective study, the effectiveness and toxicity of ICI therapy were similar to those determined in clinical trials. Our findings suggest that ICIs could be effective and well tolerated by people with advanced CSCC who are ineligible for clinical trials.

Favourable outcomes with an initial active surveillance strategy for asymptomatic radiation-induced meningiomas in long-term survivors of paediatric and young adult malignancies

PURPOSE

Radiation-induced meningiomas (RIM) are the most common secondary neoplasm post cranial radiotherapy, yet optimal surveillance and treatment strategies remain contentious. Herein, we report the clinical outcomes and radiological growth rate of RIM, diagnosed in a cohort of survivors undergoing MRI screening, with the objective of informing clinical guidelines and practice.

MATERIALS AND METHODS

Long-term survivors of paediatric or young-adult malignancies, diagnosed with RIM between 1990 and 2015, were identified. Absolute (AGR) and relative (RGR) volumetric growth rates were calculated. Rapid growth was defined as AGR > 2 cm3/year or AGR > 1 cm3/year and RGR ≥ 30% RESULTS: Fifty-two patients (87 RIM) were included. Median age at first RIM diagnosis was 33.9 (range,13.8-54.1) years. Seventy-seven (88%) RIM were asymptomatic at detection. Median follow-up time from first RIM detection was 11 (range, 0.6-28) years. Median absolute and relative volumetric growth rates were 0.05 (IQR 0.01-0.11) cm3 and 26 (IQR 7-79) % per year, respectively. Two (3.3%) RIM demonstrated rapid growth. Active surveillance was adopted for 67 (77%) RIM in 40 patients. Neurological sequelae due to RIM progression were reported in 5% of patients on active surveillance. Surgery was performed for 33 RIM (30 patients): 18 (54.5%) at diagnosis and 15 (45.5%) after active surveillance. Histopathology was WHO Grade 1 (85.2%), 2 (11.1%), 3 (3.7%). Following resection, 10-year local recurrence rate was 12%. During follow-up, 19 (37%) survivors developed multiple RIM.

CONCLUSIONS

Asymptomatic RIM are typically low-grade tumours which exhibit slow growth. Active surveillance appears to be a safe initial strategy for asymptomatic RIM, associated with a low rate of neurological morbidity.

The HI-FIVE Trial: A Prospective Trial Using 4-Dimensional 68Ga Ventilation-Perfusion Positron Emission Tomography-Computed Tomography for Functional Lung Avoidance in Locally Advanced Non-small Cell Lung Cancer

PURPOSE

Functional lung avoidance (FLA) radiation therapy aims to spare regions of functional lung to reduce toxicity. We report the results of the first prospective trial of FLA using 4-dimensional gallium 68 ventilation-perfusion positron emission tomography-computed tomography (68Ga-4D-V/Q PET/CT).

METHODS AND MATERIALS

Inclusion criteria required a diagnosis of stage III non-small cell lung cancer and the ability to undergo radical-intent chemoradiation therapy. Functional volumes were generated using planning 68Ga-4D-V/Q PET/CT. These volumes were used to generate a clinical FLA plan to 60 Gy in 30 fractions. The primary tumor was boosted to 69 Gy. A comparison anatomic plan was generated for each patient. Feasibility was met if FLA plans (compared with anatomic plans) allowed (1) a reduction in functional mean lung dose of ≥2% and a reduction in the functional lung volume receiving 20 Gy (fV20Gy) of ≥4%, and (2) a mean heart dose ≤30 Gy and relative heart volume receiving 50 Gy of <25%.

RESULTS

In total, 19 patients were recruited; 1 withdrew consent. Eighteen patients underwent chemoradiation with FLA. Of the 18 patients, 15 met criteria for feasibility. All patients completed the entire course of chemoradiation therapy. Using FLA resulted in an average reduction of the functional mean lung dose of 12.4% (SD, ±12.8%) and a mean relative reduction of the fV20Gy of 22.9% (SD, ±11.9%). At 12 months, Kaplan-Meier estimates for overall survival were 83% (95% CI, 56%-94%) and estimates for progression-free survival were 50% (95% CI, 26%-70%). Quality-of-life scores were stable across all time points.

CONCLUSIONS

Using 68Ga-4D-V/Q PET/CT to image and avoid functional lung is feasible.

Comprehensive profiling identifies tumour and immune microenvironmental differences in clinical subsets of cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinomas (cSCCs) are the second most diagnosed skin cancer worldwide; however, little is known about the pathobiological factors that contribute to the diverse clinical outcomes seen.

OBJECTIVES

To profile cSCCs comprehensively and identify the pathological processes that contribute to the disparities seen in their clinical behaviour.

METHODS

We characterized the genomic, transcriptomic and immunohistochemical profiles of 211 cSCC tumours, including 37 cSCCs from immunocompromised patients.

RESULTS

cSCCs from immunocompromised patients were characterized by a lack of B cells in the peritumoral stroma compared with immunocompetent patients. Further, an abundance of a memory B-cell-like population in the peritumoral stroma was associated with a better prognosis in all patients (immunocompetent and immunocompromised), as well as only immunocompetent patients. No differences in genetic -variants, tumour mutational burden or mutational signatures were observed between cSCCs from immunocompetent and immunocompromised patients. Thus, differences in survival between cSCCs from immunocompromised patients and immunocompetent patients are not likely to be driven by tumour genomic factors, but may be associated with differential host immune response. cSCC not from a primary head and neck site had lower tumour mutational burden and exhibited upregulation of the epithelial-mesenchymal transition programme compared with head and neck cSCC. Both factors were implicated with poorer responses to immune checkpoint inhibition, and the latter with poorer survival.

CONCLUSIONS

We identified tumour and host immune factors that contribute to the disparate clinical behaviour of cSCC, with broad translational application, including prognostication, treatment prediction to current therapies and the identification of novel anticancer therapy approaches in cSCC.

TROG 15.03/ANZUP International Multicenter Phase II Trial of Focal Ablative STereotactic RAdiotherapy for Cancers of the Kidney (FASTRACK II)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) is an emerging non-invasive alternative for primary renal cell cancer (RCC) in patients unsuitable for surgery. The objective of the FASTRACK II clinical trial was to investigate the efficacy of SBRT for primary RCC.

MATERIALS/METHODS

This non-randomized, intergroup multi-institutional phase II study was activated in 7 Australian centers and 1 Dutch center, through the Trans Tasman Radiation Oncology Group (TROG) and the Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP). Eligible patients had biopsy confirmed diagnosis of primary RCC with a single lesion within a kidney, ECOG performance ≤2 and were medically inoperable, high risk or declined surgery. For tumors ≤4 cm a single fraction of 26 Gy was prescribed, for tumors > 4 cm, 42 Gy in three fractions was prescribed. The primary outcome of the study was to estimate the efficacy of SBRT for primary RCC, defined as local control based on RECIST criteria. The study was powered assuming that 1-year local control would be 90%, with the null hypothesis of ≤80% considered undesirable and not worthy of proceeding to a future randomized controlled trial.

RESULTS

Between July 2016 and February 2020, 70 patients were enrolled with a median follow-up of 42 months. Median age was 77 years. Forty-nine patients were male (70%), median BMI was 32 and median Charlson comorbidity score was 7. The median [IQR] RENAL complexity score was 8 [7-10]. Biopsy confirmation was 100%. Twenty-three patients (33%) had T1a disease. The median (interquartile range [IQR]) tumor size was 4.6cm [3.7-5.5]; it was 3.3cm [3.0-3.6] in those receiving single fraction (n = 23), and 5.3cm [4.6-6.0] in those receiving 3-fraction SBRT (n = 47). During real-time pre-treatment quality assurance review, 10 cases (14.3%) required resubmission for protocol deviation, 2119 variables were assessed at final review, and final protocol compliance was 99.3%. Seven (10%) patients experienced grade 3 treatment-related adverse events, with no grade 4 or 5 events observed. Eleven (16%) patients reported no adverse events. Local control was 100% throughout the lifetime of the trial (p<0.001). Cancer-specific survival was also 100% throughout the lifetime of the trial. Freedom from distant failure (95% CIs) at 1 and 3 years was 99% (90-100%). Overall survival (95% CIs) at 1 and 3 years was 99% (90-100%) and 82% (70-89%), respectively. Baseline mean eGFR (95% CI) was 61.1 mLs/min (56.6; 65.6) and reduced by -10.8 mLs/min (-13.0; -8.6) by 1-year, by -14.6 mLs/min (-17.0; -12.2) by 2-years and plateaued thereafter.

CONCLUSION

In the first multicenter prospective trial of a non-surgical primary RCC cohort, enrolling mostly T1b+ disease, SBRT was an effective treatment strategy with no observed local failures. We observed an acceptable side effect profile and renal function after SBRT. These outcomes support the design of a future randomized clinical trial of SBRT versus surgery for primary RCC. The trial was registered with ID: NCT02613819.

SABRSeq: A Randomized Phase Ib Trial of SABR Sequencing with Pembrolizumab in Metastatic Non-Small Cell Lung Cancer (NSCLC)

PURPOSE/OBJECTIVE(S)

The optimal sequencing of stereotactic ablative body radiotherapy (SABR) with anti-PD1 checkpoint blockade is unknown. The purpose of SABRseq was to assess the toxicity of the combination of SABR delivered either before or after the commencement of pembrolizumab. The central hypothesis is that the treatment combination will have a safety profile that is clinically acceptable and demonstrate anti-tumor efficacy. Furthermore, we hypothesize that differences in systemic immune activation will be observed between treatment arms.

MATERIALS/METHODS

This was a single institutional phase Ib randomized clinical trial (Trial ID NCT03307759). Eligible patients had metastatic NSCLC, ECOG performance 0-1, and had not received prior checkpoint immunotherapy, high-dose radiation (>36 Gy) within 6 months, or either systemic or radiation therapy within 4 weeks of randomization. Eligible patients had either TPS≥50% PD-L1 expression in the first-line or TPS≥1% PD-L1 expression with prior chemotherapy exposure. Patients were randomized to SABR before the commencement of pembrolizumab [ARM1] or SABR commencing after pembrolizumab [ARM2]. SABR was delivered in a single fraction of 18-20 Gy to 1-3 lesions. The primary endpoint was treatment-related adverse events (AE's) related to SABR and/or pembrolizumab. Secondary endpoints included best overall response (BOR), overall survival (OS), and progression-free survival (PFS). Translational objectives included the evaluation of longitudinal changes in immunological cellular subsets within peripheral blood to explore changes in systemic immunity and circulating tumor DNA (ctDNA) dynamics.

RESULTS

Between December 2017 and December 2019, 13 patients were randomized. The median follow-up was 37 months. The study was closed early due to poor accrual. Median age was 66 years, with 11 patients (84%) having adenocarcinoma. Nine (69%) were enrolled in the first-line setting. The median [range] number of lesions was 6 [3-11]. The median [range] cycles of pembrolizumab delivered in ARM 1 was 13 [12-32] and ARM 2 was 9 [3-34]. Grade 3 treatment-related AEs were experienced in 0 of 5 patients in ARM1 and in 1 of 8 patients in ARM 2 (hyperglycemia). There were no grade 4 or 5 adverse events reported. The BOR by both RECIST and iRECIST criteria was CR in one patient, PR in seven patients, SD in five patients. Median (95% Cis) PFS was 12.4 months (6.3-21.0), and median (95% Cis) OS was 47.1 months (12.6-not reached; 2-year point estimate 62% [31-82]). Mass cytometry was used on serial peripheral blood samples to examine changes in the frequency of immune cells, changes in T cell activation, differentiation and functional polarization state. Targeted sequencing was performed to assess ctDNA. Translational outcomes will be presented.

CONCLUSION

There was no evidence of a concerning safety signal from either SABR before or after start of pembrolizumab. The combination demonstrated activity with promising PFS and OS and is worthy of evaluation in larger randomized trials.

The relationship between tumour dosimetry, response, and overall survival in patients with unresectable Neuroendocrine Neoplasms (NEN) treated with 177Lu DOTATATE (LuTate)

Peptide Receptor Radionuclide Therapy (PRRT) delivers targeted radiation to Somatostatin Receptor (SSR) expressing Neuroendocrine Neoplasms (NEN). We sought to assess the predictive and prognostic implications of tumour dosimetry with respect to response by 68 Ga DOTATATE (GaTate) PET/CT molecular imaging tumour volume of SSR (MITVSSR) change and RECIST 1.1, and overall survival (OS).

METHODS

Patients with gastro-entero-pancreatic (GEP) NEN who received LuTate followed by quantitative SPECT/CT (Q-SPECT/CT) the next day (Jul 2010 to Jan 2019) were retrospectively reviewed. Single time-point (STP) lesional dosimetry was performed for each cycle using population-based pharmacokinetic modelling. MITVSSR and RECIST 1.1 were measured at 3-months post PRRT.

RESULTS

Median of 4 PRRT cycles were administered to 90 patients (range 2-5 cycles; mean 27.4 GBq cumulative activity; mean 7.6 GBq per cycle). 68% received at least one cycle with radiosensitising chemotherapy (RSC). RECIST 1.1 partial response was 24%, with 70% stable and 7% progressive disease. Cycle 1 radiation dose in measurable lesions was associated with local response (odds ratio 1.5 per 50 Gy [95% CI: 1.1-2.0], p = 0.002) when adjusted by tumour grade and RSC. Median change in MITVSSR was -63% (interquartile range -84 to -29), with no correlation with radiation dose to the most avid lesion on univariable or multivariant analyses (5.6 per 10 Gy [95% CI: -1.6, 12.8], p = 0.133). OS at 5-years was 68% (95% CI: 56-78%). Neither baseline MITVSSR (hazard ratio 1.1 [95% CI: 1.0, 1.2], p = 0.128) nor change in baseline MITVSSR (hazard ratio 1.0 [95% CI: 1.0, 1.1], p = 0.223) were associated with OS when adjusted by tumour grade and RSC but RSC was (95% CI: 0.2, 0.8, p = 0.012).

CONCLUSION

Radiation dose to tumour during PRRT was predictive of radiologic response but not survival. Survival outcomes may relate to other biological factors. There was no evidence that MITVSSR change was associated with OS, but a larger study is needed.

NeoAdjuvant pembrolizumab and STEreotactic radiotherapy prior to nephrectomy for renal cell carcinoma (NAPSTER): A phase II randomised clinical trial

Background

Surgery remains the standard of care for localised renal cell carcinoma (RCC). Nevertheless, nearly 50% of patients with high-risk disease experience relapse after surgery, with distant sites being common. Considering improved outcomes in terms of disease-free survival with adjuvant immunotherapy with pembrolizumab, we hypothesise that neoadjuvant SABR with or without the addition of pembrolizumab before nephrectomy will lead to improved disease outcomes by evoking better immune response in the presence of an extensive reserve of tumor-associated antigens.

Methods and analysis

This prospective, open-label, phase II, randomised, non-comparative, clinical trial will investigate the use of neoadjuvant stereotactic ablative body radiotherapy (SABR) with or without pembrolizumab prior to nephrectomy. The trial will be conducted at two centres in Australia that are well established for delivering SABR to primary RCC patients. Twenty-six patients with biopsy-proven clear cell RCC will be recruited over two years. Patients will be randomised to either SABR or SABR/pembrolizumab. Patients in both arms will undergo surgery at 9 weeks after completion of experimental treatment. The primary objectives are to describe major pathological response and changes in tumour-responsive T-cells from baseline pre-treatment biopsy in each arm. Patients will be followed for sixty days post-surgery.

Outcomes and significance

We hypothesize that SABR alone or SABR plus pembrolizumab will induce significant tumor-specific immune response and major pathological response. In that case, either one or both arms could justifiably be used as a neoadjuvant treatment approach in future randomized trials in the high-risk patient population.

Long-Term Outcomes of TROG 13.01 SAFRON II Randomized Trial of Single- Versus Multifraction Stereotactic Ablative Body Radiotherapy for Pulmonary Oligometastases

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.In a randomized phase II clinical trial, the Trans Tasman Radiation Oncology Group compared single- versus multifraction stereotactic ablative body radiotherapy (SABR) in 90 patients with 133 oligometastases to the lung. The study found no differences in safety, efficacy, systemic immunogenicity, or survival between arms, with single-fraction SABR picked as the winner on the basis of cost-effectiveness. In this article, we report the final updated survival outcome analysis. The protocol mandated no concurrent or post-therapy systemic therapy until progression. Modified disease-free survival (mDFS) was defined as any progression not addressable by local therapy, or death. At a median follow-up of 5.4 years, the 3- and 5-year estimates for overall survival (OS) were 70% (95% CI, 59 to 78) and 51% (95% CI, 39 to 61). There were no significant differences between the multi- and single-fraction arms for OS (hazard ratio [HR], 1.1 [95% CI, 0.6 to 2.0]; P = .81). The 3- and 5-year estimates for disease-free survival were 24% (95% CI, 16 to 33) and 20% (95% CI, 13 to 29), with no differences between arms (HR, 1.0 [95% CI, 0.6 to 1.6]; P = .92). The 3- and 5-year estimates for mDFS were 39% (95% CI, 29 to 49) and 34% (95% CI, 24 to 44), with no differences between arms (HR, 1.0 [95% CI, 0.6 to 1.8]; P = .90). In this patient population, where patients receive SABR in lieu of systemic therapy, one-in-three patients are alive without disease in the long term. There were no differences in outcomes by fractionation schedule.

Are dynamic or fixed FDG-PET measures of disease of greater prognostic value in patients with relapsed/refractory diffuse large B-cell lymphoma undergoing autologous haematopoietic stem cell transplantation?

Positron emission tomography (PET) response assessment using the Deauville score has prognostic utility in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem-cell transplantation (ASCT). Improved predictive methods are required to identify patients with poor outcomes who may be better considered for other salvage options. We investigated the prognostic value of mean tumour volume (MTV) and maximum standardised uptake value (SUVmax) at pre-salvage and pre-ASCT time-points, and the quantitative changes between scans (∆MTV and ∆SUVmax). One hundred and twenty-five patients with R/R DLBCL underwent salvage immunochemotherapy and ASCT: 80 patients had pre-salvage PET and 90 had pre-ASCT PET available. With a median follow-up of 5.6 years, 5-year progression-free survival (PFS) and overall survival (OS) were 52% and 65%, respectively. For patients with PET-positive residual disease after salvage therapy, pre-ASCT MTV was a significant negative prognosticator for PFS (HR 1.19 per 100 ml, p < 0.001) and OS (HR 1.78 per 100 ml, p < 0.001). Similarly, pre-ASCT SUVmax was negatively associated with PFS (HR 1.08, p < 0.001) and OS (HR 1.08, p < 0.001). Notably, pre-salvage MTV and SUVmax and ∆MTV and ∆SUVmax were not associated with PFS or OS. In conclusion, pre-ASCT MTV and SUVmax appear to be of greater predictive value than the degree of response. Potential application may exist for PET-directed management of R/R DLBCL patients.

Patient-report symptom severity, health-related quality of life and emotional distress trajectories during and after radiotherapy for HPV-associated oropharyngeal cancer: a XXXX.XXXX secondary analysis

PURPOSE/OBJECTIVES

This secondary analysis of clinical trial XXXX.XXXX, involving patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPVOPSCC), aimed to identify patient-reported outcomes (PRO) trajectories before, during and following chemoradiotherapy.

MATERIALS/METHODS

Head and neck cancer symptom severity (HNSS) and interference (HNSI), generic health-related quality of life (HRQL) and emotional distress were assessed with the MDASI-HN, FACT-G and HADS questionnaires, respectively. Latent class growth mixture modelling (LCGMM) was used to identify distinct underlying trajectories. Baseline and treatment variables were compared between trajectory groups.

RESULTS

The LCGMM identified latent trajectories for all PROs: HNSS, HNSI, HRQL, anxiety and depression. Four HNSS trajectories (HNSS1-4) were identified, distinguished by differences in HNSS at baseline, during the peak of treatment symptoms and during early and intermediate recovery. All trajectories were stable beyond 12m. The reference trajectory (HNSS4, n=74) score was 0.1 (95%CI 0.1-0.2) at baseline, peaking at 4.6 (95%CI 4.2-5.0), with rapid early recovery (1.1, 95%CI 0.8-2.2) and gradual improvement to 12m (0.6, 95%CI 0.5-0.8). Patients in HNSS2 ("high baseline", n=30) reported higher baseline scores (1.4, 95%CI 0.8-2.0) but were otherwise similar to HNSS4. Patients in HNSS3 ("low acute", n=53) reported reduced acute symptoms (2.5, 95%CI 2.2-2.9) with stable scores beyond 9w post chemoradiotherapy (1.1, 95%CI 0.9-1.4). Patients in HNSS1 ("slow recovery", n=25) had slower recovery from an acute peak of 4.9 (95%CI 4.3-5.6) to 0.9 (95%CI 0.6-1.3) at 12m. Age, performance status, education, receipt of cetuximab and baseline anxiety varied between trajectories. The other PRO models demonstrated clinically relevant trajectories, with distinct associations with baseline factors.

CONCLUSION

LCGMM identified distinct PRO trajectories during and after chemoradiotherapy. These and their associations with variations in HPVOPSCC patients' characteristics and treatment factors provide clinically relevant insights into identifying patients who may require increased support before, during or after chemoradiotherapy.

Merkel cell carcinoma: a forty-year experience at the Peter MacCallum Cancer Centre

BACKGROUND

Merkel cell carcinoma (MCC) is a rare but highly aggressive neuroendocrine skin malignancy, with Australia having the highest reported incidence in the world. There is currently a lack of consensus regarding optimal management of this disease.

METHODS

This was a retrospective audit conducted by reviewing existing medical records of MCC patients presenting to the Peter MacCallum Cancer Centre (PMCC) between 1980 and 2018. The primary endpoint was locoregional recurrence. The secondary endpoints were distant recurrence, disease-free survival (DFS) and overall survival (OS).

RESULTS

A total of 533 patients were identified. Locoregional recurrence occurring at one, two and 5 years was 24, 31 and 32%, respectively. The estimated 5-year OS and DFS were 46% (95% Confidence Interval [CI] 41-51%) and 34% (95% CI 30-39%) respectively. Older age at diagnosis (hazard ratio [HR] per year = 1.07, 95% CI 1.06-1.07, p < 0.001), and larger primary tumour diameter (HR =1.16, 95% CI 1.03-1.31, p = 0.019) were associated with worse OS on multivariable analysis. Positive or negative histopathological margin status was not associated with OS or DFS differences in patients treated with post-operative radiotherapy.

CONCLUSIONS

In our study, about a third of patients developed locoregional recurrence, distal recurrence or both, and there appears to be no change over the last four decades. If treated with adjuvant radiotherapy, there is no difference in OS or DFS with positive surgical margins. Findings should influence future guidelines.

Prognostic stratification of HPV-associated oropharyngeal cancer based on CD103+ immune cell abundance in patients treated on TROG 12.01 and De-ESCALaTE randomized trials

BACKGROUND

High CD103+ intratumoral immune cell (ITIC) abundance is associated with better prognosis in unselected patients with human papilloma virus-associated oropharyngeal squamous cell carcinoma (HPV-associated OPSCC) treated with cisplatin and radiotherapy (CIS/RT). Substituting cetuximab (CETUX) for CIS with RT in HPV-associated OPSCC resulted in inferior efficacy. Our aim was to determine whether quantification of CD103 ITIC could be used to identify a population of HPV-associated OPSCC with superior prognosis.

PATIENTS AND METHODS

We pooled data from the TROG 12.01 and De-ESCALaTE randomized trials that compared CETUX/70GyRT with CIS/70GyRT in low-risk HPV-associated OPSCC: American Joint Committee on Cancer 7 stage III (excluding T1-2N1) or stage IV (excluding N2b-c if smoking history >10 pack-years and/or distant metastases), including all patients with available tumor samples. The primary endpoint was failure-free survival (FFS) in patients receiving CETUX/RT comparing CD103+ ITIC high (≥30%) versus low (<30%). High and low CD103 were compared using Cox regression adjusting for age, stage and trial.

RESULTS

Tumor samples were available in 159/182 patients on TROG 12.01 and 145/334 on De-ESCALaTE. CD103+ ITIC abundance was high in 27% of patients. The median follow-up was 3.2 years. The 3-year FFS in patients treated with CETUX/RT was 93% [95% confidence interval (CI) 79% to 98%] in high CD103 and 74% (95% CI 63% to 81%) in low CD103 [adjusted hazard ratio = 0.22 (95% CI 0.12-0.41), P < 0.001]. The 3-year overall survival in patients treated with CETUX/RT was 100% in high CD103 and 86% (95% CI 76% to 92%) in low CD103, P < 0.001. In patients treated with CIS/RT, there was no significant difference in FFS.

CONCLUSIONS

CD103+ ITIC expression separates CETUX/RT-treated low-risk HPV-associated OPSCC into excellent and poor prognosis subgroups. The high CD103 population is a rational target for de-intensification trials.

IGNITE: A phase II signal-seeking trial of adavosertib targeting recurrent high-grade, serous ovarian cancer with cyclin E1 overexpression with and without gene amplification

5515

Background: Cyclin E1 gene amplification and protein over-expression is a marker of platinum resistance in high grade serous ovarian, fallopian tube or primary peritoneal cancer (HGSC), and may predict response to WEE1 inhibition. Adavosertib, a WEE1 inhibitor, has demonstrated activity in unselected women with recurrent ovarian and serous endometrial cancer. We aimed to evaluate the efficacy of adavosertib in women with recurrent platinum resistant HGSC with cyclin E1 over-expression, with and without gene amplification. Methods: IGNITE is a multicentre, phase 2 trial with 2 cohorts of women with recurrent platinum resistant HGSC. Tumors were assessed for cyclin E1 protein expression by IHC and CCNE1 copy number by FISH. Patients were assigned to Cohort 1 if tumors were cyclin E1 over-expressed (H-score>50) and amplified (≥8 copies), and Cohort 2 if tumors were overexpressed and nonamplified. Patients with evaluable disease by RECIST v1.1 or GCIG CA-125 criteria were included. Adavosertib 300mg PO was given daily on days 1-5 and 8-12 of a 21-day cycle. The primary endpoint was investigator assessed clinical benefit (CB) defined as absence of progression for ≥ 18 weeks. Here we present the 18-week response data for the first 32 patients treated from Cohort 2, with a data cut-off of August 2021. Results: Between Jan-2020 and May-2021, 32 patients were accrued to Cohort 2. Median age was 62 years (range 42-77) and 84% had received ≥2 prior lines of chemotherapy. Median cyclin E1 IHC H-score was 120 and 28 patients (88%) had measurable disease by RECIST. Median number of cycles commenced was 8 (range 1-19). Overall response rate (ORR) was 53% and CB rate was 61% for all evaluable patients. Seventeen patients (53%) required a dose reduction, most commonly for neutropenia or fatigue. Seventeen patients experienced ≥Grade 3 treatment related adverse event, and 4 patients (15%) discontinued due to toxicity. Conclusions: The efficacy results in a biomarker-selected cohort of patients are promising with a higher response rate than reported in previous studies of adavosertib in unselected women with recurrent HGSC. Duration of response and progression free survival data will be presented as data matures. Clinical trial information: ACTRN12619001185156P. [Table: see text]

Circulating tumour cells (CTCs) and PSMA PET correlates in the phase I PRINCE trial of 177Lu-PSMA-617 plus pembrolizumab for metastatic castration resistant prostate cancer (mCRPC)

5027

Background: The Phase I PRINCE trial (NCT03658447) is evaluating the efficacy of 177Lu-PSMA-617 plus pembrolizumab for mCRPC. The utility of serial monitoring of CTCs and PET as biomarkers of prognosis and clinical benefit of 177Lu-PSMA-617-based therapy remains unknown. Methods: 36 of 37 pts with high PSMA expression on PSMA PET underwent serial CTC collections in conjunction with PSMA PET at baseline, every 12 weeks for 48 weeks and every 24 weeks thereafter. CK+, CD45- CTCs were enumerated from 3ml of blood and stained for PSMA (Epic Sciences platform). Associations between PSMA+ CTC counts, PET molecular tumor volume (MTV), total lesional activity (TLA; MTVxSUVmean) were assessed by Spearman correlation. Cox models assessed the association of CTC and PSMA PET parameters with radiographic progression-free survival (rPFS) and PSA PFS. A subset of pre-treatment CTCs underwent single cell low-pass whole genome sequencing to characterize copy number aberrations. Results: 32/36 pt (89%) had detectable CTCs (median 7, range 0-514) with 23 (64%) being PSMA+ (median 1, range 0-224) at baseline. At w12, 23/33 (70%) had CTCs detected with 10 (30%) being PSMA+. Baseline PSMA+ CTC count and MTV were moderately correlated (rs= 0.57, p < 0.001). Of 22 evaluable pts with baseline PSMA+ CTC, 18 (82%) showed decrease by w12 with clearance in 13. This paralleled reductions in MTV (-18% med relative change, IQR: -57 to -1) and TLA (-48% med relative change, IQR: -77 to -28). Total CTC and PSMA+ CTC counts at baseline, and PET parameters were not associated with PSA PFS or rPFS. Clearance of PSMA+ CTC by w12 (13/22 pts) was associated with improved rPFS (med NR vs 3.0 mos, HR 0.23, 95%CI 0.07-0.74, p = 0.007) and PSA PFS (med 11.2 vs 3.5 mos, HR 0.28, 95%CI 0.11-0.73, p = 0.006). Persisting PSMA-neg CTCs at w12 trended to worse rPFS (med 4.1 vs 12.3 mos, p = 0.11) and PSA PFS (med 5.1 vs 12.3 mos, p = 0.07). Of pts not progressing by w12, decrease in PSA (HR 0.83 per 10% decrease, 95%CI 0.74-0.93, p < 0.001), MTV (HR 0.85 per 10% decrease, 95%CI 0.75-0.96, p = 0.008), MTV > 30% decrease (HR 0.30, 95% CI 0.08-1.08, p = 0.05) and TLA (HR 0.88 per 10% decrease, 95%CI 0.78-1.00, p = 0.04) associated with improved rPFS beyond w12. Pre-treatment CTCs (18 pts) exhibited genomic heterogeneity and frequent loss of PTEN, TP53 and RB1. Pts with compound TP53 and RB1 loss at baseline nonetheless had PSMA+ CTCs in high proportion (med 91.3% of total CTCs). Conclusions: PSMA PET-positive mCRPC is associated with high rates of PSMA+ CTCs which decline with 177Lu-PSMA-617 plus pembrolizumab in parallel with PSMA MTV/TLA. Despite imaging suitability for therapy, CTCs had heterogenous PSMA expression and genomic alterations associated with aggressive disease. Early changes in PSMA+ CTCs and MTV/TLA were associated with outcomes and may aid in determining clinical activity of LuPSMA-based therapy.

PRINCE: Phase I trial of 177Lu-PSMA-617 in combination with pembrolizumab in patients with metastatic castration-resistant prostate cancer (mCRPC)

5017

Background: The VISION and TheraP trials have established the safety and efficacy of 177Lu-PSMA-617 in mCRPC with a 50% PSA response rate (PSA50-RR) of 46% and 66% and median progression free survival (PFS) of 8.7 and 5.1 months, respectively. More effective treatments are required as disease progression remains universal. Immunotherapy has limited single-agent efficacy in mCRPC. We hypothesise that by potentially inducing immunogenic cell death, 177Lu-PSMA-617 may act synergistically with pembrolizumab, an anti-programmed death 1 inhibitor, to enhance the depth and durability of response. PRINCE is a Phase I trial evaluating the safety and efficacy of this combination. Methods: mCRPC patients with high PSMA expression (SUVmax ≥ 20 in an index lesion, SUVmax > 10 for all lesions ≥ 10mm), and no FDG+ve/PSMA-ve lesions on paired baseline PET/CT screening, received up to 6 cycles of 177Lu-PSMA-617 (starting at 8.5 GBq, reducing by 0.5 GBq with each cycle) every 6 weeks in conjunction with 200mg of pembrolizumab every 3 weeks for up to 2 years. Response evaluation was undertaken as per PCWG3 and RECIST criteria. Co-primary endpoints were safety and PSA50-RR. Secondary endpoints included PSA-PFS, radiographic PFS (rPFS), overall survival (OS), and patient reported outcomes (PROs). This analysis was undertaken after the last patient had 12 months follow-up. Results: 37 patients (median age 72 years; prior docetaxel 73%; prior androgen receptor targeted agent 100%) received a median of 5 cycles (range: 2 to 6) of 177Lu-PSMA-617 and 12 doses (range: 6 to 19) of pembrolizumab. The median follow up was 16 months. PSA50-RR was 76% (28/37 [95% CI 59-88]) and 7/10 (70%) patients with RECIST-measurable disease had a partial response. Median rPFS, PSA-PFS and OS was 11.2 months (95% CI: 5.1-14.1), 8.2 months (95% CI: 5.1-11.2) and 17.8 months (95% CI:13.4-not estimable). 12-month rPFS and OS was 38% (95% CI: 22-54) and 83% (95% CI: 67-92), respectively. Common (≥10%) treatment-related adverse events (TRAE) were mainly Grade (G) 1-2, including xerostomia (78%), fatigue (43%), pruritus (27%), nausea (27%), rash (24%), diarrhoea (14%), anorexia (16%), thrombocytopenia (16%), elevated ALT (11%), arthralgia (11%) and a flare in bone pain (11%). Haematologic TRAEs included G2-3 anaemia (8%), G1-2 thrombocytopenia (16%), and G1 neutropenia (3%). G3 immune-related AEs occurred in 10 (27%) patients with no dominant manifestation. 5 (14%) patients discontinued pembrolizumab due to toxicity. PROs including BPI-SF and FACT-P were stable throughout the study. Conclusions: The combination of 177Lu-PSMA-617 and pembrolizumab had promising activity. Toxicities were generally consistent with those of single-agent 177Lu-PSMA-617 and pembrolizumab and were not clearly augmented by combination use. No new safety concerns were observed. Clinical trial information: NCT03658447.

Abstract PD10-02: A randomised phase II trial of single fraction or multi-fraction SABR (stereotactic ablative body radiotherapy) with atezolizumab in patients with advanced triple negative breast cancer (AZTEC trial)

A randomised phase II trial of single fraction or multi-fraction SABR (stereotactic ablative body radiotherapy) with atezolizumab in patients with advanced triple negative breast cancer (AZTEC trial) Abstract: BACKGROUND: In patients with advanced triple negative breast cancer (TNBC), immunotherapy has shown acceptable safety and efficacy in a PD-L1 (programmed death-ligand 1) positive population. Pre-clinical evidence has demonstrated that SABR can prime a more effective systemic anti-tumor response in combination with checkpoint inhibition. It is currently unknown if single or multi-fraction SABR scheduling synergises best with atezolizumab therapy. METHODS: This was a multi-centre, open label, phase 2 randomised trial of patients with advanced TNBC, unselected for (PD-L1) status, who had recurred at least 6 months post completion of (neo) adjuvant chemotherapy and received less than 2 lines of treatment in the metastatic setting. Participants were randomised to 20Gy SABR in 1 fraction or 24Gy SABR in 3 fractions to 1-4 sites of disease, with at least one metastasis left unirradiated. Within 5 days following the final fraction of radiotherapy atezolizumab was commenced at a dose of 1200 mg every 21 days and continued for up to 24 months, or until progression or intolerable toxicity. The primary endpoint is progression- free survival (PFS). Secondary endpoints include efficacy according to PD-L1 IHC status (positive: SP142 ≥1%) and TIL (tumour infiltrating lymphocyte) quantity, response assessment, overall survival and safety. Results presented are from interim analysis performed 18 weeks after the last patient commenced treatment. RESULTS: Fifty evaluable patients were recruited and randomised between 20th November 2018 and 12thApril 2021 with a median age of 57 [35 - 79] yrs. Thirty (60%) and 20 (40%) patients had received none or one previous line of chemotherapy in the metastatic setting, respectively. 14/40 (35%) patients were PD-L1 positive at baseline and 26/42 (62%) had TIL≥5%. Median follow-up was 17 months. The median PFS for the 20 Gy arm was 2.5 (90% CI: 1.7-4.5) months, 3.1 (90% CI: 1.8-3.9) months for the 24 Gy arm. For both arms combined, the PFS was 3.1 (90% CI: 1.8-3.9) months, with no difference between the arms, HR 1.2 (95% CI: 0.6-2.1), p=0.64. PFS by PD-L1 IHC status and TIL&lt;5% vs ≥5% was similar. There were 11 (22%) patients with clinical benefit (no PD within 24 weeks of C1D1), these were not significantly different by arm (p=0.74), nor by PD-L1 status (p=0.44) or TIL quantity (p=0.92) (Table 1). Overall survival is immature: estimated 12 months was 78% (95% CI:54-90) for the 20 Gy arm and 57% (95% CI: 33-75) for the 24 Gy arm.. In patients who were PD-L1 positive the ORR was 1/12 (8%) and DC was 3/14 (21%) compared with ORR of 1/14 (7%) and DC of 3/26 (12%) in patients who were PD-L1 negative.

CONCLUSIONS: The efficacy between single and multi-fraction SABR in combination with Atezolizumab was similar and toxicity was acceptable. Efficacy was seen in PD-L1 positive and negative patients. Longer follow-up is required to assess the effect on OS.. (Research support and funding provided by the imCORE Network on behalf of F. Hoffmann-La Roche; AZTEC ClinicalTrials.gov Identifier: NCT03464942)

Table 1.Response AssessmentResponse, n (%)All patients (n = 50)Patients with measurable disease (n = 32)Best objective response (non-SABR lesion)CR3 (6)2 (6)PR2 (4)2(6)NCR/NPD8 (16)0SD13 (26)13 (41)PD24 (48)15 (47)ORR (CR + PR)5 (10); 95% CI: 3-224 (12%); 95% CI: 4-29DCR (CR + PR + SD + non-CR/non-PD ≥24 weeks)a11 (22%); 95% CI: 12-377 (23%); 95% CI: 10-41aOne patient withdrew at 8 weeks and was not assessable for DCR.

Citation Format: Steven David, Peter Savas, Shankar Siva, Michelle White, Michael W Neeson, Shane White, Gavin Marx, Robyn Cheuk, Michelle Grogan, Maria Farrell, Jessica Foudoulis, Annette Dempsey, Paul J Neeson, Mathias Bressel, Sherene Loi. A randomised phase II trial of single fraction or multi-fraction SABR (stereotactic ablative body radiotherapy) with atezolizumab in patients with advanced triple negative breast cancer (AZTEC trial) [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 PD10-02.

Stereotactic Radiotherapy and Short-course Pembrolizumab for Oligometastatic Renal Cell Carcinoma-The RAPPORT Trial

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) is an option for oligometastatic clear cell renal cell carcinoma (ccRCC) but is limited by a lack of prospective clinical trial data.

OBJECTIVE

The RAPPORT trial evaluated the safety and efficacy of total metastatic irradiation followed by short-course anti-programmed death receptor-1 immunotherapy in patients with oligometastatic ccRCC.

DESIGN SETTING, AND PARTICIPANTS

RAPPORT was a single-arm multi-institutional phase I/II trial (NCT02855203). Patients with two or fewer lines of prior systemic therapy and one to five oligometastases from ccRCC were eligible.

INTERVENTION

A single fraction of 20 Gy SABR (or if not feasible, ten fractions of 3 Gy) was given to all metastatic sites, followed by pembrolizumab 200 mg administered Q3W for eight cycles.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The endpoints were adverse events (AEs), disease control rate (DCR) for at least 6 mo, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The Kaplan-Meier method was used for time-to-event endpoints. Freedom from local progression (FFLP) was assessed per lesion adding patient as a cluster effect.

RESULTS AND LIMITATIONS

Thirty evaluable patients, with a median age of 62 yr, were enrolled. The median follow-up was 28 mo. There were 44% of patients with intermediate-risk and 56% with favorable-risk disease. Eighty-three oligometastases were irradiated (median three per patient): eight adrenal, 11 bone, 43 lung, 12 lymph node, and nine soft tissue. Four patients (13%) had grade 3 treatment-related AEs: pneumonitis (n = 2), dyspnea (n = 1), and elevated alkaline phosphatase/alanine transaminase (n = 1). There were no grade 4 or 5 AEs. FFLP at 2 yr was 92%. ORR was 63% and DCR was 83%. Estimated 1- and 2-yr OS was 90% and 74%, respectively, and PFS was 60% and 45%, respectively. Limitations include a single-arm design and selected patient population.

CONCLUSIONS

SABR and short-course pembrolizumab in oligometastatic ccRCC is well tolerated, with excellent local control. Durable responses and encouraging PFS were observed, warranting further investigation.

PATIENT SUMMARY

The RAPPORT trial investigated the combination of high-dose precision radiotherapy and a short course of immunotherapy in patients with low-volume metastatic kidney cancer. We found that this treatment regimen was well tolerated, with excellent cancer control in sites of known disease. A proportion of patients were free from cancer relapse in the longer term, and these encouraging findings warrant further investigation.

Cutaneous squamous cell carcinoma metastatic to the axilla and groin: Outcomes and prognostic factors

PURPOSE

This study examined the clinical outcomes and prognostic factors of patients with metastatic cutaneous SCC metastatic to the axilla and groin when managed with curative-intent lymphadenectomy and received (neo)adjuvant treatment.

METHODS AND MATERIALS

We conducted a single institution retrospective review. Patients who had nodal disease without distant spread were 18 years or older with no non-cutaneous primary identified.

RESULTS

From January 2000 to July 2015, 78 patients were treated for axilla (64, 82%) or inguinal (14, 18%) involvement with cSCC. The median age was 75.5 years (range: 29-95), and 8 patients (11%) were immunosuppressed. The median size of the largest node was 45 mm (range: 8-135), and extracapsular extension was found in 63 (81%) cases. A majority of patients were treated with surgery alone (21, 26.9%) and surgery with adjuvant radiation therapy (54, 69%). The 2-year OS and PFS were 50% (95% CI: 40%-63%) and 43% (95% CI: 33%-56%), and 5-year OS and PFS were 33% (95% CI:23%-47%) and 32% (95% CI:22%-46%) respectively in the entire cohort. On univariable analysis, factors associated with longer OS were as follows: younger age (HR 1.1, 95% CI: 0.9-1.3 P = 0.021), improved performance status (HR 1.5, 95% CI:1.0-2.3 P = 0.026), lack of immunosuppression (HR 3.3, 95% CI: 1.5-7.3 P = 0.001), lower lymph node ratio (HR 1.2, 95% CI:1.0-1.3 P = 0.007), lower number of positive nodes (HR 1.1, 95% CI:1.0-1.2 P = 0.004) and the use of radiation therapy (HR 0.5, 95% CI:0.3-0.9 P = 0.012).

CONCLUSION

Metastasis to the axilla and groin with cSCC has poor outcomes with standard treatment. The addition of immunotherapy warrants investigation.

Symptom burden, quality of life, functioning and emotional distress in survivors of human papillomavirus associated oropharyngeal cancer: An Australian cohort

BACKGROUND

This cross-sectional study examines patient-reported outcomes and functioning-based subgroups in human papillomavirus-associated oropharyngeal cancer survivors treated with chemoradiotherapy ≥12 months prior.

METHOD

Survivors completed EORTC QLQ-C30, MDASI-HN and PROMIS-Emotional distress questionnaires. Subgroups were identified via two-step clustering of QLQ-C30 functioning scales.

RESULTS

136 patients were enrolled. Clinicians' graded 19/136 (14%) patients as having at least one severe (Grade 3 CTCAE) toxicity, whereas 68/136 (50%) patients self-reported at least one toxicity in the severe range (MDASI-HN ≥ 7). QLQ-C30 Global health status score (mean 76, SD = 20) was comparable to population norms. Rates of moderate/severe anxiety (10%/1%) and depression (4%/1%) were low. Two functioning-based subgroups were formed based on auto-clustering statistics: high- (n = 93) and low-functioning (n = 41). Differences on all functioning scales were large (d: 1.57-2.29), as were differences on the remaining QLQ-C30 scales/items, most MDASI-HN symptom severity/interference scales, and PROMIS scales (d: 0.80-2.03). Differences and associations with patient/clinical characteristics were not significant.

CONCLUSION

In this Australian cohort of HPV-OPC survivors there was significant discordance between clinician- and patient-reported toxicity. We observed population comparable global quality of life and low rates of emotional distress. However, we identified a low-functioning subgroup reporting significantly worse outcomes on a range of patient-reported measures who may benefit from targeted support.

Single-Fraction vs Multifraction Stereotactic Ablative Body Radiotherapy for Pulmonary Oligometastases (SAFRON II): The Trans Tasman Radiation Oncology Group 13.01 Phase 2 Randomized Clinical Trial

Importance

Evidence is lacking from randomized clinical trials to guide the optimal approach for stereotactic ablative body radiotherapy (SABR) in patients with pulmonary oligometastases.

Objective

To assess whether single-fraction or multifraction SABR is more effective for the treatment of patients with pulmonary oligometastases.

Design, Setting, and Participants

This multicenter, unblinded, phase 2 randomized clinical trial of 90 patients across 13 centers in Australia and New Zealand enrolled patients with 1 to 3 lung oligometastases less than or equal to 5 cm from any nonhematologic malignant tumors located away from the central airways, Eastern Cooperative Oncology Group performance status 0 or 1, and all primary and extrathoracic disease controlled with local therapy. Enrollment was from January 1, 2015, to December 31, 2018, with a minimum patient follow-up of 2 years.

Interventions

Single fraction of 28 Gy (single-fraction arm) or 4 fractions of 12 Gy (multifraction arm) to each oligometastasis.

Main Outcomes and Measures

The main outcome was grade 3 or higher treatment-related adverse events (AEs) occurring within 1 year of SABR. Secondary outcomes were freedom from local failure, overall survival, disease-free survival, and patient-reported outcomes (MD Anderson Symptom Inventory-Lung Cancer and EuroQol 5-dimension visual analog scale).

Results

Ninety participants were randomized, of whom 87 were treated for 133 pulmonary oligometastases. The mean (SD) age was 66.6 [11.6] years; 58 (64%) were male. Median follow-up was 36.5 months (interquartile range, 24.8-43.9 months). The numbers of grade 3 or higher AEs related to treatment at 1 year were 2 (5%; 80% CI, 1%-13%) in the single-fraction arm and 1 (3%; 80% CI, 0%-10%) in the multifraction arm, with no significant difference observed between arms. One grade 5 AE occurred in the multifraction arm. No significant differences were found between the multifraction arm and single-fraction arm for freedom from local failure (hazard ratio [HR], 0.5; 95% CI, 0.2-1.3; P = .13), overall survival (HR, 1.5; 95% CI, 0.6-3.7; P = .44), or disease-free survival (HR, 1.0; 95% CI, 0.6-1.6; P > .99). There were no significant differences observed in patient-reported outcomes.

Conclusions and Relevance

In this randomized clinical trial, neither arm demonstrated evidence of superior safety, efficacy, or symptom burden; however, single-fraction SABR is more efficient to deliver. Therefore, single-fraction SABR, as assessed by the most acceptable outcome profile from all end points, could be chosen to escalate to future studies.

Trial Registration

ClinicalTrials.gov Identifier: NCT01965223.

A retrospective review of the long-term outcomes of online adaptive radiation therapy and conventional radiation therapy for muscle invasive bladder cancer

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Risks with tight adaptive RT margins.

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Cancer control may be poorer if margins tight.

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Prospective studies required.

Background and Purpose

To report long-term outcomes of online image-guided (IG) adaptive radiation therapy (aRT) versus conventional IG radiation therapy (cRT) for bladder preservation in muscle-invasive bladder cancer (MIBC).

Materials and Methods

A retrospective review of patients with histologically proven MIBC who were prescribed radical intent radiation therapy (RT) following trans-urethral resection of bladder tumour (TURBT) was conducted. There were three groups based on their RT treatment modality: conventional RT (cRT), margin 5 mm adaptive RT (aRT5mm) and margin 7 mm adaptive RT (aRT7mm).

Results

171 patients were included in this study, with median age of 79.4 years (41–90). Approximately half of all patients received concurrent chemotherapy. N = 57 underwent cRT, n = 39 underwent aRT5mm, and n = 75 underwent aRT7mm. Response evaluable patients in all three groups (n = 133) had high rates of complete response (CR, 83%) on first post-RT cystoscopy with no significant differences between the groups. At a median follow-up of 54 months, the 5-year freedom from muscle-invasive failure survival (FFMIFS) in the cRT, aRT5mm, and aRT7mm groups were 75%, 59%, and 98%, respectively. The estimated cancer specific survival (CSS) at 5 years were 60%, 30%, and 59%, respectively. The estimated overall survival (OS) at 5 years were 43%, 26%, and 38%, respectively. The incidence of late grade 3 or 4 toxicity was n = 5 in aRT5mm, n = 2 in cRT group, and n = 1 in aRT7mm.

Conclusion

IG aRT with 7 mm expansion for MIBC provides higher rates of FFMIFS, similar 5-year CSS and OS, as well as toxicity outcomes when compared to cRT. aRT with 5 mm expansion with this RT protocol is not recommended for treatment.

Nodal metabolic tumour volume on baseline 18 F-FDG PET/CT and overall survival in stage II and III NSCLC patients undergoing curative-intent chemoradiotherapy/radiotherapy

INTRODUCTION

This study aims to investigate whether nodal metabolic tumour volume (nMTV) and nodal total lesion glycolysis (nTLG) on Fluorine-18 fluoro-deoxy-glucose positron emission tomography-computed tomography (¹⁸ F-FDG PET/CT) in inoperable node-positive stage II and III non-small cell lung cancer (NSCLC) are independent predictors of overall survival (OS) in patients undergoing curative-intent chemoradiotherapy/radiotherapy (CRT/RT).

METHODS

Data from two prospective trials between 2004 and 2016 were analysed retrospectively. Primary, nodal and total metabolic tumour volume and total lesion glycolysis (pMTV, nMTV, tMTV, pTLG, nTLG and tTLG, respectively) were derived from baseline ¹⁸ F-FDG PET/CT. Cox regressions were used to model OS by ¹⁸ F-FDG PET/CT parameters adjusting for overall stage.

RESULTS

89 patients with stage II (8%) and stage III (92%) were included. The median age at diagnosis was 67 years; 62% were male. The median follow-up was 6.9 years; the median OS was 2.2 years (95% CI 1.7-3.1). The median pMTV, nMTV and tMTV were 14 mL (range 0-360), 8 mL (range 0-250) and 34 mL (range 3-384), respectively. In 3 patients, the primary lesion could not be delineated from the central hilar mass. There was no association between nMTV (adjusted HR 1.04, 95% CI 0.95-1.15, P-value 0.43), pMTV (adjusted HR 1.0, 95% CI 0.96-1.04, P-value 0.92), tMTV (adjusted HR 1.0, 95% CI 0.97-1.04, P-value 0.88), nTLG, pTLG or tTLG and OS. Consistent results were noted when patients with central hilar lesions were excluded from analysis.

CONCLUSION

In node-positive stage II and III NSCLC patients who underwent ¹⁸ F-FDG PET/CT-guided target delineation curative-intent concurrent CRT/RT, metabolic parameters did not appear to provide independent prognostication.

Fear of Cancer Recurrence in Survivors of Human Papillomavirus-Associated Oropharyngeal Carcinoma

PURPOSE

To estimate the prevalence of and characteristics associated with fear of cancer recurrence (FCR) among human papillomavirus (HPV)-associated oropharyngeal cancer (OPC) survivors.

METHODS AND MATERIALS

We conducted a cross-sectional study in HPV-OPC survivors ≥12 months from completion of definitive (chemo)radiation therapy (RT/CRT). Eligible patients completed the Fear of Cancer Recurrence Inventory short-form (FCRI-SF), the European Organisation for research and Treatment of Cancer QLQ-C30, MD Anderson Symptom Inventory-Head and Neck, and PROMIS Anxiety and Depression short forms. Associations between FCRI-SF scores and other variables were investigated using linear regression models.

RESULTS

A total of 136 HPV-OPC survivors were enrolled; the median age was 61 years (range, 42-87 years), 84% were male, 72% were currently partnered, 83% were current nonsmokers, 67% were regular alcohol consumers, and the median time since treatment was 2.8 years (range, 1.0-5.5 years). Clinical levels of FCR (≥13) were observed in 72 of 135 patients (53%; 95% confidence interval [CI], 45%-62%). Characteristics significantly associated with increasing FCR scores were younger age (-0.9/5 years; 95% CI, -1.7 to -0.01; P = .031), lower global quality of life (-0.8/10 unit increase; 95% CI, -1.4 to -0.2; P = .012), higher symptom interference (0.8/unit increase; 95% CI, 0.1-1.5; P = .017), and a higher burden of anxiety (0.4/unit; 95% CI, 0.3-0.5; P <.001) and depression (0.3/unit; 95% CI, 0.1-0.4; P <.001). Other sociodemographic tumor- and treatment-related characteristics were not statistically significant. Compared with patients reporting nonclinical levels of FCR, significantly more patients reporting clinical levels of FCR than expected believed professional psychological assistance would have been beneficial (60% vs 33%; P = .002).

CONCLUSIONS

Clinical levels of FCR were observed in approximately half of the HPV-OPC survivors. Survivors reporting higher FCR were younger with worse self-reported global quality of life and higher symptom interference and emotional distress. No other patient, tumor, or treatment factors were associated with higher FCR.

Prospective Phase II trial of radiation therapy in localised non-gastric marginal zone lymphoma with prospective evaluation of autoimmunity and Helicobacter pylori status: TROG 05.02/ALLG NHL15

BACKGROUND

This Phase 2 multicentre trial in localised non-gastric marginal zone lymphoma (MZL) evaluated the effectiveness and safety of radiotherapy and documented markers of autoimmunity and Helicobacter pylori infection.

PATIENTS AND METHODS

Eligible patients had Stages I and II or paired-organ, non-gastric MZL. Bone marrow evaluation, autoantibody panel, and H. pylori evaluation were mandatory. Involved-field or involved-site radiotherapy was delivered to 24-30.6 Gy. Detected H. pylori infections underwent eradication.

RESULTS

Between 2006 and 2014, six centres enrolled 70 patients, and 68 commenced treatment. The median age was 59 (range: 23-84) years, and 31 (46%) were male. Overall, 55 patients had Stage I disease, nine patients had Stage II disease, and four patients had paired organ-confined disease. Involved extranodal sites with three or more cases were orbital (n = 18), conjunctiva (n = 13), lacrimal (n = 8), skin (n = 8), salivary (n = 7), and muscle (n = 4). Eight patients had primary nodal MZL. At the median follow-up of 5 years (range 0.7-9.4), progression-free survival and overall survival were 79% and 95%, respectively. One lymphoma-related death and two in-field failures (after 25 and 30 Gy, respectively) occurred. Distant relapse sites were skin (n = 2), lymph nodes (n = 2), duodenum, stomach, muscle, and conjunctiva (1 each). No paired-organ MZL relapsed. Apart from cataracts (n = 18), only three treatment-related late grade ≥3 adverse events occurred. Autoantibodies or autoimmune events were detected in 26 of 68 patients (38%). H. pylori infection was detected in 15 of 63 patients (24%) tested. Neither autoimmunity nor H. pylori was detected in 27 of 68 patients (40%).

CONCLUSIONS

Radiotherapy was a potentially curative treatment with low toxicity in localised non-gastric MZL. Autoimmunity, H. pylori infection or both were detected in 60% of patients.

Evaluation of the Impact of Magnetic Resonance Imaging with Susceptibility-weighted Imaging for Screening and Surveillance of Radiation-induced Cavernomas in Long-term Survivors of Malignancy

AIMS

Radiation-induced cavernomas (RIC) are common late toxicities in long-term survivors of malignancy following cerebral irradiation. However, the natural history of RIC is poorly described. We report the first series of long-term surveillance of RIC using modern magnetic resonance imaging (MRI) including highly sensitive susceptibility-weighted imaging (SWI). The aims of this research were to better characterise the natural history of RIC and investigate the utility of MRI-SWI for screening and surveillance.

MATERIALS AND METHODS

Eligibility required long-term survivors of malignancy with previous exposure to cerebral irradiation and RIC identified on MRI-SWI surveillance. The number and size of RIC were reported on Baseline MRI-SWI and last Follow-up MRI-SWI.

RESULTS

In total, 113 long-term survivors with RIC underwent MRI-SWI surveillance; 109 (96%) were asymptomatic at the time of RIC diagnosis. The median age at cerebral irradiation was 9.3 years; the median radiotherapy dose was 50.4 Gy. The median time from cerebral irradiation to Baseline MRI-SWI was 17.9 years. On Baseline MRI-SWI, RIC multiplicity was present in 89% of patients; 34% had >10 RIC; 65% had RIC ≥4 mm. The median follow-up from Baseline MRI-SWI was 7.3 years. On Follow-up MRI-SWI, 96% of patients had multiple RIC; 62% had >10 RIC; 72% had RIC ≥4 mm. Of the 109 asymptomatic patients at RIC diagnosis, 96% remained free from RIC-related symptoms at 10 years. Only two required neurosurgical intervention for RIC; there was no RIC-related mortality.

CONCLUSIONS

RIC are commonly multiple, asymptomatic and typically increase in size and number over time. Our findings suggest that MRI-SWI for screening of RIC is unlikely to influence longer term intervention in asymptomatic cancer survivors. In the absence of neurological symptoms, assessment or monitoring of RIC are insufficient indications for MRI-SWI surveillance for long-term survivors of malignancy with past exposure to cerebral irradiation.

Identification of good and poor prognosis HPV associated oropharyngeal cancer based on CD103 immune cell expression in patients treated with cetuximab and radiotherapy on TROG 12.01 and De-ESCALaTE randomized trials

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Background: Trials in human papilloma virus associated oropharyngeal squamous cell carcinoma (HPVOPSCC), substituting cetuximab (CETUX) for cisplatin (CIS) with radiotherapy (RT), resulted in decreased efficacy without improved toxicity or symptom burden. We reported that high intratumoral immune cell (ITIC) CD103 expression (> 30%), a marker of tissue-resident memory T cells, is associated with better prognosis in unselected patients with HPVOPSCC treated with CIS/RT. In this study our aim was to determine whether low risk HPVOPSCC patients treated with CETUX/RT with high CD103 have a superior prognosis. Methods: TROG 12.01 and De-ESCALaTE are randomised multicentre trials that compared 70Gy RT/CETUX with 70Gy RT/CIS (weekly in TROG 12.01, 3-weekly in De-ESCALaTE) in patients with HPVOPSCC, low risk by Ang criteria: AJCC 7th Stage III (excluding T1-2N1) or stage IV (excluding N2b-c if smoking history > 10 pack years and/or distant metastases). In TROG 12.01 T4 and/or N3 patients were also excluded. Eligible patients required tumor samples available for immune cell quantification on immunohistochemistry. Data from the two trials were pooled, with analyses performed in eligible randomised patients who commenced treatment. The primary endpoint was failure-free survival (FFS) in patients receiving CETUX/ RT comparing CD103 ITIC > 30% (high) vs. < 30% (low). High/low CD103 were compared using Cox model adjusting for age, stage and trial. Results: Samples for CD103 testing were available in 159/182 patients on TROG 12.01 and 145/334 on De-ESCALaTE. ITIC CD103 expression was high in 26% of patients. The median follow-up was 3.2 years. The 3 -year failure-free survival rates in patients treated with CETUX/RT were 92% (95% CI: 78-97%) in high CD103 and 74% (95% CI: 64-82%) in low CD103, adjusted HR 0.25 (95% CI: 0.14-0.44); p < 0.001. The 3 -year overall survival (OS) in patients treated with CETUX/RT were 100% in high CD103 and 86% (95% CI: 76-92%) in low CD103, p < 0.001. Superior FFS in the high CD103 group was independent of stage. In patients treated with CIS/RT there was no significant difference in FFS (3-year 86% in high CD103 and 90% in low CD103; p = 0.55) or in OS (3-year 100% in high CD103 and 95% in low CD103; p = 0.14). The increase in failures in the low CD103 patients treated with CETUX/RT was evenly split between distant and locoregional failures. Conclusions: ITIC CD103 separates CETUX/RT treated low risk HPVOPSCC into excellent and poor prognosis subgroups. In a low risk population CIS/RT achieves excellent outcomes in both high and low ITIC CD103 groups. The high ITIC CD103 population is a rational target for future de-intensification trials.

Randomized trial of radiotherapy with weekly cisplatin or cetuximab in low risk HPV associated oropharyngeal cancer (TROG 12.01): A Trans-Tasman Radiation Oncology Group study

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Background: The excellent prognosis of patients with low risk HPV associated oropharyngeal squamous cell carcinoma has led to concerns about overtreatment and excessive toxicity with radiotherapy and cisplatin, leading to interest in de-intensification trials. We investigated whether cetuximab, an EGFR targeting antibody, when combined with radiotherapy would result in a decrease in symptom burden and toxicity with similar efficacy when compared to weekly cisplatin. Methods: TROG 12.01, a randomised, multicentre trial involving 15 sites in Australia and New Zealand enrolled patients with HPV associated oropharyngeal squamous cell carcinoma, AJCC 7th edition Stage III (excluding T1-2N1) or stage IV (excluding T4 and/or N3 and/or N2b-c if smoking history >10 pack years and/or distant metastases). Patients were randomised (1:1) to receive radiotherapy (70Gy in 35 fractions) with either weekly cisplatin, 7 doses of 40mg/m2 or cetuximab, loading dose of 400mg/m2 followed by 7 weekly doses of 250 mg/m2. The primary outcome was symptom severity assessed by the MD Anderson Symptom Inventory Head and Neck Symptom Severity Scale from baseline to 13 weeks post completion of radiotherapy using the area under the time-severity curve (AUC). Sample size was 170 evaluable patients to provide at least 90% power to detect an effect size of 0.5, using a 2-sided test at 0.05 level of significance. Trial was registered on ClinicalTrials.gov: NCT01855451. Results: Between 17th June 2013 and 7th June 2018, 189 patients were enrolled and 182 were evaluable, with 92 on cisplatin arm and 90 on cetuximab included in the main analysis. The median follow-up was 4.1 years (0.4 - 5.3). Analyses were performed in all eligible randomised patients that commenced treatment (modified intention-to-treat population). There was no difference in the primary endpoint of symptom severity; difference in AUC cetuximab – cisplatin was 0.05 (95%CI: -0.19, 0.30), p= 0.66. The T-score (mean number of > grade 3 acute adverse events) was 4.35 (SD 2.48) in the cisplatin arm and 3.82 (SD 1.8) in the cetuximab arm, p= 0.108. The 3 -year failure-free survival rates were 93% (95% CI: 86-97%) in the cisplatin arm and 80% (95% CI: 70-87%) in the cetuximab arm (hazard ratio = 3.0 (95% CI: 1.2-7.7); p=0.015. The increase in failures in the cetuximab arm was evenly split between distant and locoregional failures. Conclusions: For patients with low risk HPV associated oropharyngeal cancer, radiotherapy and cetuximab had inferior failure-free survival without improvement in symptom burden or toxicity compared to radiotherapy and weekly cisplatin. Radiotherapy and cisplatin remains the standard of care. Clinical trial information: NCT01855451.

Randomised trial of radiotherapy with weekly cisplatin or cetuximab in low risk HPV associated oropharyngeal cancer (TROG 12.01) - a Trans-Tasman Radiation Oncology Group study

BACKGROUND

The excellent prognosis of patients with low risk HPV associated oropharyngeal squamous cell carcinoma has led to concerns about overtreatment and excessive toxicity with radiotherapy and cisplatin, leading to interest in de-intensification trials. We investigated whether cetuximab, an EGFR targeting antibody, when combined with radiotherapy would result in a decrease in symptom burden and toxicity with similar efficacy when compared to weekly cisplatin.

METHODS

XXXX, a randomised, multicentre trial involving 15 sites in XXXX enrolled patients with HPV associated oropharyngeal squamous cell carcinoma, AJCC 7^th edition Stage III (excluding T1-2N1) or stage IV (excluding T4 and/or N3 and/or N2b-c if smoking history >10 pack years and/or distant metastases). Patients were randomised (1:1) to receive radiotherapy (70Gy in 35 fractions) with either weekly cisplatin, 7 doses of 40mg/m² or cetuximab, loading dose of 400mg/m² followed by 7 weekly doses of 250 mg/m². The primary outcome was symptom severity assessed by the MD Anderson Symptom Inventory Head and Neck Symptom Severity Scale from baseline to 13 weeks post completion of radiotherapy using the area under the curve (AUC). Trial was registered on ClinicalTrials.gov: XXXX RESULTS: Between 17^th June 2013 and 7^th June 2018, 189 patients were enrolled, with 92 on cisplatin arm and 90 on cetuximab included in the main analysis. There was no difference in the primary endpoint of symptom severity; difference in AUC cetuximab - cisplatin was 0.05 (95%CI: -0.19, 0.30), p= 0.66. The T-score (mean number of ≥ grade 3 acute adverse events) was 4.35 (SD 2.48) in the cisplatin arm and 3.82 (SD 1.8) in the cetuximab arm, p= 0.108. The 3 -year failure-free survival rates were 93% (95% CI: 86-97%) in the cisplatin arm and 80% (95% CI: 70-87%) in the cetuximab arm (hazard ratio = 3.0 (95% CI: 1.2-7.7); p=0.015.

CONCLUSIONS

For patients with low risk HPV associated oropharyngeal cancer, radiotherapy and cetuximab had inferior failure-free survival without improvement in symptom burden or toxicity compared to radiotherapy and weekly cisplatin. Radiotherapy and cisplatin remains the standard of care.

UpFrontPSMA: a randomized phase 2 study of sequential 177 Lu-PSMA-617 and docetaxel vs docetaxel in metastatic hormone-naïve prostate cancer (clinical trial protocol)

OBJECTIVE

To assess the activity and safety of sequential lutetium-177 (¹⁷⁷ Lu)-PSMA-617 and docetaxel vs docetaxel on a background of androgen deprivation therapy (ADT) in men with de novo metastatic hormone-naïve prostate cancer (mHNPC).

PATIENTS AND METHODS

UpFrontPSMA (NCT04343885) is an open-label, randomized, multicentre, phase 2 trial, recruiting 140 patients at 12 Australian centres. Key eligibility criteria include: prostate cancer with a histological diagnosis within 12 weeks of screening commencement; prostate-specific antigen (PSA) >10 ng/mL at diagnosis; ≤4 weeks on ADT; evidence of metastatic disease on computed tomography (CT) and/or bone scan; high-volume prostate-specific membrane antigen (PSMA)-avid disease with a maximum standardized uptake value >15; and absence of extensive discordant fluorodeoxyglcuose (FDG)-positive, PSMA-negative disease. ⁶⁸ Ga-PSMA-11 and ¹⁸ F-FDG positron-emission tomography (PET)/CT undergo central review to determine eligibility. Patients are randomized 1:1 to experimental treatment, Arm A (¹⁷⁷ Lu-PSMA-617 7.5GBq q6w × 2 cycles followed by docetaxel 75 mg/m² q3w × 6 cycles), or standard-of-care treatment, Arm B (docetaxel 75 mg/m² q3w × 6 cycles). All patients receive continuous ADT. Patients are stratified based on disease volume on conventional imaging and duration of ADT at time of registration. The primary endpoint is the proportion of patients with undetectable PSA (≤0.2 ng/L) at 12 months after study treatment commencement. Secondary endpoints include safety, time to castration resistance, overall survival, PSA and radiographic progression-free survival, objective tumour response rate, early PSMA PET response, health-related quality of life, and frequency and severity of adverse events. Enrolment commenced in April 2020.

RESULTS AND CONCLUSIONS

The results of this trial will generate data on the activity and safety of ¹⁷⁷ Lu-PSMA-617 in men with de novo mHNPC in a randomized phase 2 design.

Stereotactic radiotherapy for oligoprogressive ER-positive breast cancer (AVATAR)

BACKGROUND

The enhanced knowledge of cancer biology has led to considerable advancement in systemic therapy for advanced breast cancer. Recently, studies showed that cyclin-dependent kinase (CDK) 4/6 inhibitor, when added to endocrine therapy, had improved the outcomes of patients with advanced ER-positive HER2-negative breast cancer. However, the disease often progresses following a period of treatment response. In a subset of patients, disease progression may occur at limited sites, i.e., oligoprogressive disease (OPD). In the past few years, stereotactic radiotherapy (SRT) has emerged as a safe and effective treatment for advanced cancer when delivered to limited metastatic sites. Hence, it is worth investigating the role of SRT in the setting of oligoprogressive breast cancer.

METHOD

AVATAR is a multicentre phase II registry trial of SRT with endocrine therapy and CDK 4/6 inhibitor for the management of advanced ER-positive HER2-negative breast cancer. The study aims to enrol 32 patients with OPD limited to 5 lesions. The primary endpoint of the study is time to change systemic therapy measured from the commencement of SRT to change in systemic therapy. Secondary objectives include overall survival, progression free survival and treatment related toxicity. The exploratory objective is to describe the time to change in systemic therapy by the site (bone only vs. non-bone lesions) and number (1 vs. > 1) of OPD.

DISCUSSION

This study aims to explore the effect of SRT in maximising the benefit of systemic therapy in patients with oligoprogressive ER-positive HER2-negative breast cancer. This approach might help reduce the burden of disease and improve the life quality in these patients.

TRIAL REGISTRATION

ACTRN, ACTRN12620001212943 . Date of registration 16 November 2020- Retrospectively registered.

Contralateral neck failure in oral tongue cancer: Outcomes from two centers using predefined treatment criteria

BACKGROUND

The objective was to determine the incidence of, and factors associated with contralateral neck failure (CNF) in oral tongue squamous cell carcinoma (OTSCC).

METHODS

Consecutive patients with OTSCC between 2007 and 2016 were included. The predefined policy of the contralateral neck included neck dissection (ND) where the primary tumor extended/crossed midline or the contralateral neck was involved; and elective nodal irradiation (ENI) where the primary tumor was ≤1 cm from midline/2 cm from tip.

RESULTS

This study included 258 patients. ND was ipsilateral 169 (66%) and bilateral 33 (13%). Fifty-five patients (21%) received ENI to the undissected contralateral neck. CNF occurred in 19 patients (7%) and was similar by treatment received. Utilizing this approach, we observed higher rates of CNF with increasing N classification, perineural invasion, extracapsular extension, and depth of invasion ≥6 mm.

CONCLUSIONS

Using our institutional policy of treatment to the contralateral neck, a low rate of CNF (≤10%) was observed.