Outcomes Following Radiation Therapy (RT) for Very Young Age CNS Embryonal Tumors on COG ACNS0334 According to Molecular-Confirmed Diagnosis

PURPOSE/OBJECTIVE(S)

The outcomes of upfront or relapse radiation therapy (RT) for the Children's Oncology Group ACNS0334 protocol based on molecular diagnosis were assessed. Therapy included maximal safe surgery, high-dose chemotherapy with stem cell rescue, randomization for inclusion of high dose methotrexate (MTX) and optional RT.

MATERIALS/METHODS

There were 24 patients that received RT on COG ACNS0334 of 77 evaluable patients with a diagnosis of either high-risk medulloblastoma (MB) or supratentorial primitive neuroectodermal tumor (SPNET). RT was a recommendation (M0: Focal, M+: CSI 18 Gy) given young patient age <36 months at enrollment. Seven RT patients were excluded for ineligible pathology (1 ATRT, 1 HGG) or insufficient tissue. The aim of this report is to review outcomes of 17 patients on ACNS0334 receiving RT (8 Upfront, 9 at relapse) with a molecular diagnosis that included MB, Pineoblastoma (PB), or Embryonal tumor with multilayered rosettes (ETMR).

RESULTS

In the MB group, there were 9 patients irradiated with MB (Group 3 = 8, SHH = 1). 5-year OS for MB Group 3 receiving RT (median primary dose 54 Gy) was 62.5% with no difference observed comparing 6 patients treated with upfront RT versus 2 treated at relapse (p = 0.27). All upfront RT for MB Group 3 had initial partial response (PR) to 0334 chemotherapy. RT delivery for upfront RT MB Group 3 included craniospinal radiation (CSI) in 5 patients and 1 patient who received focal RT to the primary (50 Gy) and metastatic site (44 Gy). Eighty percent of CSI for upfront RT in Group 3 was 18 Gy or 23.4 Gy. Relapse RT for MB Group 3 (2 patients) utilized full dose CSI (36 Gy, 39.6 Gy) and both patients are survivors with 5+ years follow-up. CSI dose for Group 3 MB was higher for relapse RT (mean 37.8 Gy) as compared to upfront RT (mean 19.8 Gy, p = 0.013). Use of MTX was 50% in both upfront RT and relapse RT Group 3 MB cohorts. One patient with MB SHH (classic histology) underwent upfront focal RT (54 Gy) after initial PR to systemic therapy (without MTX) and is surviving 5+ years. PB: Of 4 PB patients (median primary dose 48.8 Gy) 1 had RT upfront (CSI 18 Gy) and 3 had RT at relapse (1 patient received CSI, 21 Gy). All patients with PB expired within 2 years. MTX was given in 75% (including 1 upfront RT PB). Two of 3 patients treated at relapse had prior complete response (CR). ETMR: All 4 patients (median primary dose 54 Gy) with ETMR were treated at relapse, with CSI given in 1 patient (23.4 Gy). All patients with ETMR expired within 2 years, and 2 (50%) had received MTX. Two patients (50%) had initial CR.

CONCLUSION

The RT cohort for Group 3 MB on ACNS0334 exhibited long-term survival both for both upfront and relapse RT, however relapsed Group 3 MB received higher dose CSI. RT upfront for MB, including one surviving MB SHH patient receiving focal RT, was solely given for incomplete initial chemotherapy response. There were no survivors for either PB or ETMR when the majority (88%) were treated at relapse.

Focal versus craniospinal radiation for disseminated atypical teratoid/rhabdoid tumor following favorable response to systemic therapy

PURPOSE

Radiotherapy (RT) is associated with improved survival in atypical teratoid/rhabdoid tumor (ATRT); however, optimal RT delivery is unknown. A meta-analysis was conducted for disseminated (M+) ATRT receiving focal or craniospinal radiation (CSI).

METHODS

After abstract screening, 25 studies (1995-2020) contained necessary patient, disease, and radiation treatment information (N = 96). All abstract, full text, and data capture were independently double-reviewed. The corresponding author was contacted for cases of insufficient information. Response to pre-radiation chemotherapy (N = 57) was categorized as complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). Univariate and multivariate statistics were performed to investigate survival correlation. Patients with M4 disease were excluded.

RESULTS

The 2- and 4-year overall survival (OS) was 63.8% and 45.7%, respectively, with a median follow-up of 2 years (range 0.3-13.5). The median age was 2 years (range 0.2-19.5), and 96% received chemotherapy. On univariate analysis, gross total resection (GTR, p = .0007), pre-radiation chemotherapy response (p < .001), and high-dose chemotherapy with stem cell recuse (HDSCT, p = .002) correlated with survival. On multivariate analysis, pre-radiation chemotherapy response (p = .02) and GTR (p = .012) retained survival significance as compared to a trend for HDSCT (p = .072). Comparisons of focal RT (vs. CSI) and greater than or equal to 5400 cGy primary dose were nonsignificant. Following CR or PR, a statistical trend favored focal radiation (p = .089) over CSI.

CONCLUSION

Chemotherapy response prior to RT and GTR correlated with improved survival on multivariate analysis for ATRT M+ receiving RT. No benefit was observed for CSI compared to focal RT among all patients and following favorable chemotherapy response, inviting further study of focal RT for ATRT M+.

Radiotherapy for Atypical Teratoid/=Rhabdoid Tumor (ATRT) on the Pediatric Proton/Photon Consortium Registry (PPCR)

PURPOSE

Atypical teratoid/rhabdoid tumors (ATRT) of the central nervous system (CNS) are rare tumors with a poor prognosis and variable use of either focal or craniospinal (CSI) radiotherapy (RT). Outcomes on the prospective Pediatric Proton/Photon Consortium Registry (PPCR) were evaluated according to RT delivered.

METHODS

Pediatric patients receiving RT were prospectively enrolled on PPCR to collect initial patient, disease, and treatment factors as well as provide follow-up for patient outcomes. All ATRT patients with evaluable data were included. Kaplan-Meier analyses with log-rank p-values and cox proportional hazards regression were performed.

RESULTS

The PPCR ATRT cohort includes 68 evaluable ATRT patients (median age 2.6 years, range 0.71-15.40) from 2012 to 2021. Median follow-up was 40.8 months (range 3.4-107.7). Treatment included surgery (65% initial gross total resection or GTR), chemotherapy (60% with myeloablative therapy including stem cell rescue) and RT. For patients with M0 stage (n = 60), 50 (83%) had focal RT and 10 (17%) had CSI. Among patients with M + stage (n = 8), 3 had focal RT and 5 had CSI. Four-year overall survival (OS, n = 68) was 56% with no differences observed between M0 and M + stage patients (p = 0.848). Local Control (LC) at 4 years did not show a difference for lower primary dose (50-53.9 Gy) compared to ≥ 54 Gy (73.3% vs 74.7%, p = 0.83). For patients with M0 disease, four-year OS for focal RT was 54.6% and for CSI was 60% (Hazard Ratio 1.04, p = 0.95. Four-year event free survival (EFS) among M0 patients for focal RT was 45.6% and for CSI was 60% (Hazard Ratio 0.71, p = 0.519). For all patients, the 4-year OS comparing focal RT with CSI was 54.4% vs 60% respectively (p = 0.944), and the 4-year EFS for focal RT or CSI was 42.8% vs 51.4% respectively (p = 0.610).

CONCLUSION

The PPCR ATRT cohort found no differences in outcomes according to receipt of either higher primary dose or larger RT field (CSI). However, most patients were M0 and received focal RT. A lower primary dose (50.4 Gy), regardless of patient age, is appealing for further study as part of multi-modality therapy.

The Incorporation of Immunotherapy and Targeted Therapy Into Chemoradiation for Cervical Cancer: A Focused Review

In 2011 the Food and Drug Administration (FDA) approved anti-vascular endothelial growth factor (VEGF) therapy, bevacizumab, for intractable melanoma. Within the year, immunotherapy modulators inhibiting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) were approved in addition to programmed death-ligand 1 (PD-L1) antibodies in 2012. Since then, research showing the effectiveness of targeted therapies in a wide range of solid tumors has prompted studies incorporating their inclusion as part of upfront management as well as refractory or relapsed disease. For treatment of cervical cancer, which arises from known virus-driven oncogenic pathways, the incorporation of targeted therapy is a particularly attractive prospect. The current standard of care for locally advanced cervical cancer includes concurrent platinum-based chemotherapy with radiation therapy (CRT) including external beam radiation therapy (EBRT) and brachytherapy. Building upon encouraging results from trials testing bevacizumab or immunotherapy in recurrent cervical cancer, these agents have begun to be incorporated into upfront CRT strategies for prospective study. This article will review background data establishing efficacy of angiogenesis inhibitors and immunotherapy in the treatment of cervical cancer as well as results of prospective studies combining targeted therapies with standard CRT with the aim of improving outcomes. In addition, the role of immunotherapy and radiation on the tumor microenvironment (TME) will be discussed.

Abstract P3-12-02: The impact of estrogen receptor status on treatment outcomes following gamma knife radiosurgery for brain metastases of primary breast cancer

INTRODUCTION: Estrogen receptor (ER) status is a critical component of determining initial therapy of newly diagnosed breast cancer. Although 70% of primary breast malignancies are ER+, there remains limited data on whether ER status influences treatment outcomes for patients with brain metastases. Gamma Knife Radiosurgery (GKS) is increasingly being used in the management of brain metastases. The goal of this study is to determine the impact of ER status in patients receiving GKS for breast cancer metastases to brain.

METHODS: A database of consecutive breast cancer patients receiving GKS at our institution from January 2000 to March 2012 was reviewed for hormone receptor status, dates of initial brain metastasis and GKS, presence of neurologic symptoms, and recurrence of GKS-treated lesions. The main cohort was subdivided by receptor status at initial tissue diagnosis. Progression or loss of local control of the treated lesions was defined as radiographic evidence of growth (greater than 20% increase in the sum of the longest diameters) or treated lesions requiring additional treatment until death or last follow-up. Analysis for neurological symptom improvement was performed for patients with available follow-up information, with at least 1 month follow–up. Comparisons were made between subgroups using Kaplan-Meier method, Chi-square analysis and univariate comparisons with log-rank test. Significance was set at p &lt; 0.05.

RESULTS: A total of 93 breast cancer patients received GKS, and receptor status was available in 83 patients. Forty-six (45.7%) percent of patients were ER+. The median follow-up for all patients was 85.5 months (range 2.5 to 307.6). For all patients, the median number of brain metastases was 2.0 and median age at diagnosis was 54 years. According to ER status, there were no differences in patient age at diagnosis, age at GKS, or number of brain metastasis, although the time to development of brain metastasis (median 92.2 vs 34.0 months, p = 0.02) was longer in the ER+ cohort. The median GKS dose was 18 Gy. Fifty one percent of ER+ patients had GKS alone versus 54% of ER− patients (p = 0.26). There was no difference in survival from GKS according to ER status, with survival for ER+ and ER− patients of 21.3 and 16.8 months, respectively (p = 0.39). However, ER+ patients exhibited longer progression-free survival of treated metastases with 19.1 versus 7.5 months (p = 0.02). In addition, for all patients who attained local control, 10 of 22 ER+ patients had an improvement in neurologic symptoms versus 4 of 17 ER− patients (p = 0.02).

DISCUSSION: While ER positivity conveys a favorable prognosis at the time of diagnosis, survival after intensive treatment of brain metastases appears similar to ER− patients. This occurs independently of ER status, even though brain relapse was significantly more common in ER− patients, suggesting efforts to further improve extracranial systemic control may potentially enhance survival. Both local and neurologic symptom control were poorer for ER− patients. Whether alternative approaches, such as increasing GKS dose, surgical resection, and/or routine inclusion of WBRT, can improve outcomes for ER− patients with brain metastases may warrant future investigation.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-12-02.

Tolerability of and biochemical control of permanent Pd-103 brachytherapy followed by external beam radiotherapy for localized prostate adenocarcinoma

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Background: The optimal sequencing of brachytherapy and external radiotherapy (EBRT) for patients receiving combined therapy for localized prostate cancer has not been established, and in this series we report our experience of patients treated with brachytherapy followed by EBRT.

Methods: Retrospective review of patients treated with combined Pd-103 brachytherapy and EBRT with minimum of 2 years of follow-up. Variables assessed included T stage, Gleason score, pre-treatment PSA, use of androgen suppression (ADT), EBRT dose and brachytherapy dose. Biochemical failure was defined as a PSA rise of ≥ 2 ng/mL above nadir.

Results: 87 patients received Pd-103 brachytherapy (median 80 Gy) followed by EBRT (median 45 Gy). Median age was 65 years (49–80). By risk groupings (Zelefsky) 26.4% of patients were low risk, 47.1% were intermediate risk, and 26.4% were high risk. Most low risk patients had either perineural invasion or ≥ 50% involved biopsy cores. Neoadjuvant and concurrent ADT was given in 21% of patients. With a median follow-up of 56 months (range 24 to 113), there were 4 failures (all in the intermediate or high risk group), with an overall 5-year biochemical failure free survival (BFFS) of 91.8%. 2 patients had documented distant failures, while none of the presumed local failures had a positive biopsy. There was no statistical difference in BFFS based on risk group, T stage, Gleason score, initial PSA, or ADT use. The median PSA nadir was 0.1 and occurred at a median of 30 months from brachytherapy. A nadir of ≤ 0.5 was seen in 87% of patients and was associated with improved 5-year BFFS (100% vs 22%, p<.0001). The median time to PSA nadir for patients < 60 years was 34.5 months compared to 26.5 months in patients ≥ 60 (p=.036). Overall, treatment was well-tolerated with no cases of late Grade ≥ 2 rectal or urinary toxicity reported.

Conclusions: Excellent long-term disease control and low morbidity was observed for patients with localized prostate adenocarcinoma treated with interstitial brachytherapy followed by EBRT. Future prospective research assessing the relative therapeutic ratio of alternate sequencing approaches would appear warranted.