The oligometastatic state - separating truth from wishful thinking

Results of Radiation Therapy as Local Ablative Therapy for Oligometastatic Non-Small Cell Lung Cancer

Oligometastatic cancer is characterized by a limited number of metastatic deposits. Compared with lung cancer patients who have more widespread disease, oligometastatic lung cancer patients have more favorable survival outcomes. Therefore, it has been hypothesized that local ablative therapy (LAT) directed at the metastatic deposits in addition to standard-of-care systemic therapy may further improve survival outcomes in oligometastatic lung cancer patients. One LAT modality that has been utilized in oligometastatic lung cancer is radiation therapy. In particular, ultra-hypofractionated radiotherapy, also known as stereotactic body radiotherapy (SBRT), has been shown to provide excellent local control with a favorable safety profile. Here, we reviewed the retrospective studies and prospective trials that have deployed radiation therapy as LAT in oligometastatic lung cancer, including randomized studies showing benefits for progression-free survival and overall survival with the addition of LAT. We also discuss the impact of targeted therapies and immunotherapy on radiation as LAT.

Distribution Characteristics and Prognostic Value of Immune Infiltration in Oligometastatic Breast Cancer

BACKGROUND

To assess the distribution characteristics and the prognostic value of immune infiltration in female oligometastatic breast cancer patients.

METHODS

We retrospectively analyzed the clinicopathological data of oligometastatic breast cancer (OMBC) patients diagnosed between June 2000 and January 2020. Immune markers were quantified by immunohistochemistry on FFPE tissues in paired normal breast tissues, primary breast cancers and oligometastatic lesions. Survival analyses were performed using the Kaplan-Meier curves and Cox-proportional hazards model.

RESULTS

A total of 95 female OMBC patients visited Sun Yat-sen University Cancer Center between June 2000 and January 2020, and 33 of them had matched normal breast tissues, primary cancers and oligometastatic lesions and were reviewed in immune infiltration analysis. CD8 of primary tumors had a higher expression than that in matched normal tissues. The expressions of CD8 and FOXP3 were higher in the primary sites than that in the oligometastatic lesions. CD3, CD4 and CD8 were significantly lower in the intratumoral regions than that in the peritumoral regions both in primary and oligometastatic lesions. Notably, the high percentage of CD3 in the intratumoral oligometastatic lesions predicted the longer PFS and OS, and higher CD4 in the same lesions also predicted a better OS. There was obviously positive correlation between CD4/CD3 and Ki-67 in primary cancers and negative correlation between CD4/CD3 and ER in oligometastatic sites.

CONCLUSION

We explored immune distribution and evolution in time and space in OMBC to provide new understandings for biological behaviors of this disease and further divided patients in different prognosis.

Volumetric burden of metastatic lesions drives outcomes in patients with extracranial oligometastatic disease

Background

We hypothesized that the total volume of metastases at initial oligometastatic (OM) presentation to stereotactic body radiation therapy (SBRT) is an important prognostic factor that can refine the definition of OM disease.

Methods

Patients with extracranial oligometastatic cancer (≤5 lesions) treated with SBRT were included in an international multi‐institutional database. Multivariable Cox and competing risks regression models were used to determine the relationship between distant progression‐free survival (DPFS), widespread progression (WSP), and overall survival (OS) with the total planning target volume (PTV) at initial OM presentation to SBRT. All models were adjusted for histology, pre‐SBRT systemic therapy, osseous‐only lesions, and number of metastases.

Results

In total, 961 patients were included. The median follow‐up was 24.4 months (IQR: 13.8–37.5). Total PTV had a significant effect on DPFS in the first 18 months after SBRT and was most profound in the first 6 months, when each twofold increase in total PTV conferred a 40.6% increased risk of distant progression (p < 0.001). Each twofold increase in total PTV increased the risk of WSP by 45.4% in the first 6 months (p < 0.001). Total PTV had a significant effect on OS in the first 2 years after SBRT, with each twofold PTV change increasing the risk of death by 60.7% during the first 6 months (p < 0.001) and by 34% thereafter (p < 0.001). Exploratory gross tumor volume (GTV) analysis confirmed the PTV‐based observations.

Conclusion

The total volumetric burden of metastases at initial OM presentation to SBRT is strongly and independently prognostic for the risk of distant and widespread progression and survival. We propose that this metric should drive the definition of OM disease and guide treatment decision‐making.

Retrospective analysis of characteristics associated with higher-value radiotherapy episodes of care for bone metastases in Medicare fee-for-service beneficiaries

OBJECTIVES

The Centers for Medicare & Medicaid Services' newly enacted Radiation Oncology Model ('RO Model') was designed to test the cost-saving potential of prospective episode-based payments for radiation treatment for 17 cancer diagnoses by encouraging high-value care and more efficient care delivery. For bone metastases, evidence supports the use of higher-value, shorter courses of radiation (≤10 fractions). Our goal was to determine the prevalence of short radiation courses (≤10 fractions) for bone metastases and the setting, treatment and patient characteristics associated with such courses and their expenditures.

DESIGN

Using the RO Model episode file, we evaluated receipt of ≤10 fractions of radiotherapy for bone metastases and expenditures by treatment setting for Medicare fee-for-service beneficiaries during calendar years 2015-2017.Using unadjusted and adjusted regression models, we determined predictors of receipt of ≤10 fractions and expenditures. Multivariable models adjusted for treatment and patient characteristics.

RESULTS

There were 48 810 episodes for bone metastases during the period. A majority of episodes for ≤10 fractions occurred in hospital-outpatient settings (62.8% (N=22 715)). After adjusting for treatment and patient factors, hospital-outpatient treatment setting remained a significant predictor of receiving ≤10 fractions (adjusted OR 2.03 (95% CI 1.95, 2.12; p<0.001) vs free-standing). The greatest adjusted contributors to total expenditures were number of fractions (US$-3424 (95% CI US$-3412 to US$-3435) for ≤10 fractions vs >10; p<0.001) and treatment type (including US$7716 (95% CI US$7424 to US$8018) for intensity modulated radiation therapy vs conventional external beam; p<0.001).

CONCLUSIONS

A measurable performance gap exists for delivery of higher-value bone metastases radiotherapy under an episode-based model, associated with increased expenditures. The RO Model may succeed in improving the value of bone metastases radiation. Increasing the capacity of free-standing centres to implement palliative-focused services may improve the ability of these practices to succeed under the RO Model.

Diagnosis, biology and epidemiology of oligometastatic breast cancer

Does oligometastatic breast cancer (OMBC) deserve a dedicated treatment? Although some authors recommend multidisciplinary management of OMBC with a curative intent, there is no evidence proving this strategy beneficial in the absence of a randomized trial. The existing literature sheds little light on OMBC. Incidence is unknown; data available are either obsolete or biased; there is no consensus on the definition of OMBC and metastatic sites, nor on necessary imaging techniques. However, certain proposals merit consideration. Knowledge of eventual specific OMBC biological characteristics is limited to circulating tumor cell (CTC) counts. Given the data available for other cancers, studies on microRNAs (miRNAs), circulating tumor DNA (ctDNA) and genomic alterations should be developed Finally, safe and effective therapies do exist, but results of randomized trials will not be available for many years. Prospective observational cohort studies need to be implemented.

Classifying Oligometastatic Non-Small Cell Lung Cancer

An oligometastatic cancer state was first postulated in the 1990s by Hellman and Weichselbaum and described limited metastatic spread to a single or few sites of disease. It was hypothesized that this metastatic entity falls along a continuum of the natural history of cancer progression from a localized primary tumor to widespread metastases. Support for oligometastatic non-small cell lung cancer (NSCLC) has since been provided by multiple retrospective studies and then prospective randomized trials demonstrating better survival in this patient population after aggressive consolidative treatment. However, the lack of a universal definition of oligometastatic NSCLC has hindered a comparison between different studies and prevented well-defined recommendations for local consolidative treatment in this patient population. Attempts have been made to establish a common definition for use in clinical management and for the identification of inclusion criteria for future trials. In this review, we seek to summarize the current definitions of oligometastatic NSCLC based on recent expert consensus statements, previous randomized trials, and current treatment guidelines and to highlight the continued variability in current practice.

Clinical impact of PET/MRI in oligometastatic colorectal cancer

BACKGROUND

Oligometastatic colorectal cancer (CRC) is potentially curable and demands individualised strategies.

METHODS

This single-centre retrospective study investigated if positron emission tomography (PET)/magnetic resonance imaging (MR) had a clinical impact on oligometastatic CRC relative to the standard of care imaging (SCI). Adult patients with oligometastatic CRC on SCI who also underwent PET/MR between 3/2016 and 3/2019 were included. The exclusion criterion was lack of confirmatory standard of reference, either surgical pathology, intraoperative gross confirmation or imaging follow-up. SCI consisted of contrast-enhanced (CE) computed tomography (CT) of the chest/abdomen/pelvis, abdominal/pelvic CE-MR, and/or CE whole-body PET/CT with diagnostic quality (i.e. standard radiation dose) CT. Follow-up was evaluated until 3/2020.

RESULTS

Thirty-one patients constituted the cohort, 16 (52%) male, median patient age was 53 years (interquartile range: 49-65 years). PET/MR and SCI results were divergent in 19% (95% CI 9-37%) of the cases, with PET/MR leading to management changes in all of them. The diagnostic accuracy of PET/MR was 90 ± 5%, versus 71 ± 8% for SCI. In a pairwise analysis, PET/MR outperformed SCI when compared to the reference standard (p = 0.0412).

CONCLUSIONS

These findings suggest the potential usefulness of PET/MR in the management of oligometastatic CRC.

The role of the surgeon in the management of oligometastatic non-small cell lung cancer: a literature review

OBJECTIVE

In this review, we aim to summarize the most recent data on the surgical management of oligometastatic non-small cell lung cancer (NSCLC).

BACKGROUND

Approximately 60-70% of all patients with NSCLC initially present with advanced stages of cancer at time of diagnosis. These patients are generally treated with chemotherapy, radiation therapy, or a combination of these modalities. Patients with late-stage disease are usually not considered to be amenable for curative-intent treatments due to poor prognoses. Despite advances in systemic therapies, 5-year overall survival rates in these patients remain poor. However, technological advances in imaging modalities and new imaging strategies have substantially increased tumor detection rates and have resulted in a shift towards earlier diagnosis of NSCLC, possibly in stages in which metastatic disease is limited and still treatable. Studies in recent years have shown that there is a distinct group of patients with metastatic lesions at one or a few sites, often referred to as oligometastatic disease, that may have better survival outcomes compared to patients with more disseminated diseases. Furthermore, it is suggested that these patients may benefit from a combination of systemic treatment and local treatment aimed at the metastatic site(s). However, the role of surgery in this setting remains a controversial subject, with many unanswered questions.

METHODS

The PubMed/MEDLINE database and the Cochrane database were searched to find relevant articles regarding oligometastatic NSCLC. Specifically, articles regarding definitions of oligometastatic disease, oligometastatic tumor biology, diagnosis, and the treatment of oligometastatic disease were identified.

CONCLUSIONS

Oligometastatic NSCLC represents a wide spectrum of diseases and encompasses a heterogeneous patient population. Current data suggests that local ablative treatment of oligometastatic lesions with surgery or stereotactic body radiation therapy may result in improved overall survival and progression-free survival rates. However, more data from multi-center prospective trials are necessary to shed light on which therapeutic modalities are most suitable for the treatment of oligometastatic NSCLC. Integration of clinical and molecular staging data is necessary to allow for more personalized treatment approaches.

Long noncoding RNAs in cancer metastasis

Metastasis is a major contributor to cancer-associated deaths. It is characterized by a multistep process that occurs through the acquisition of molecular and phenotypic changes enabling cancer cells from a primary tumour to disseminate and colonize at distant organ sites. Over the past decade, the discovery and characterization of long noncoding RNAs (lncRNAs) have revealed the diversity of their regulatory roles, including key contributions throughout the metastatic cascade. Here, we review how lncRNAs promote metastasis by functioning in discrete pro-metastatic steps including the epithelial-mesenchymal transition, invasion and migration and organotrophic colonization, and by influencing the metastatic tumour microenvironment, often by interacting within ribonucleoprotein complexes or directly with other nucleic acid entities. We discuss well-characterized lncRNAs with in vivo phenotypes and highlight mechanistic commonalities such as convergence with the TGFβ-ZEB1/ZEB2 axis or the nuclear factor-κB pathway, in addition to lncRNAs with controversial mechanisms and the influence of methodologies on mechanistic interpretation. Furthermore, some lncRNAs can help identify tumours with increased metastatic risk and spur novel therapeutic strategies, with several lncRNAs having shown potential as novel targets for antisense oligonucleotide therapy in animal models. In addition to well-characterized examples of lncRNAs functioning in metastasis, we discuss controversies and ongoing challenges in lncRNA biology. Finally, we present areas for future study for this rapidly evolving field.

Mature Experiences Using Local Therapy for Oligometastases

Cancer is a heterogeneous disease, consisting of a spectrum of disorders ranging from local-only disease to those that are widely metastatic from their onset. The oligometastatic state, in which tumors harbor a limited number of metastases, may be curable in a subset of patients. The early success of surgical resection of hepatic metastases from colorectal cancer led to investigations into metastatectomy of other sites and, more recently, into the use of stereotactic ablative radiotherapy (SABR) for oligometastatic disease. This article reviews the data establishing the role of surgery for managing limited metastatic disease. Further, we review recent experiences using alternative local therapies, such as SABR, for oligometastases. This review also discusses ongoing trials evaluating local therapies for patients with a limited burden of metastatic cancer.

Cost-Effectiveness Analysis of Local Treatment in Oligometastatic Disease

BACKGROUND

In certain malignancies, patients with oligometastatic disease benefit from radical ablative or surgical treatment. The SABR-COMET trial demonstrated a survival benefit for oligometastatic patients randomized to local stereotactic ablative radiation (SABR) compared to patients receiving standard care (SC) alone. Our aim was to determine the cost-effectiveness of SABR.

MATERIALS AND METHODS

A decision model based on partitioned survival simulations estimated costs and quality-adjusted life years (QALY) associated with both strategies in a United States setting from a health care perspective. Analyses were performed over the trial duration of six years as well as a long-term horizon of 16 years. Model input parameters were based on the SABR-COMET trial data as well as best available and most recent data provided in the published literature. An annual discount of 3% for costs was implemented in the analysis. All costs were adjusted to 2019 US Dollars according to the United States Consumer Price Index. SABR costs were reported with an average of $11,700 per treatment. Deterministic and probabilistic sensitivity analyses were performed. Incremental costs, effectiveness, and cost-effectiveness ratios (ICER) were calculated. The willingness-to-pay (WTP) threshold was set to $100,000/QALY.

RESULTS

Based on increased overall and progression-free survival, the SABR group showed 0.78 incremental QALYs over the trial duration and 1.34 incremental QALYs over the long-term analysis. Treatment with SABR led to a marginal increase in costs compared to SC alone (SABR: $304,656; SC: $303,523 for 6 years; ICER $1,446/QALY and SABR: $402,888; SC: $350,708 for long-term analysis; ICER $38,874/QALY). Therapy with SABR remained cost-effective until treatment costs of $88,969 over the trial duration (i.e. 7.6 times the average cost). Sensitivity analysis identified a strong model impact for ongoing annual costs of oligo- and polymetastatic disease states.

CONCLUSION

Our analysis suggests that local treatment with SABR adds QALYs for patients with certain oligometastatic cancers and represents an intermediate- and long-term cost-effective treatment strategy.

Can Polymetastatic Disease Be ARRESTed Using SABR? A Dosimetric Feasibility Study to Inform Development of a Phase 1 Trial

Purpose

Phase 2 randomized trials suggest that stereotactic ablative radiation therapy improves progression-free and overall survival in patients with oligometastatic cancer, with phase 3 trials currently testing stereotactic ablative radiation therapy in up to 10 metastases. Whether stereotactic radiation therapy could provide similar benefits in polymetastatic disease (>10 metastases) is unknown. We sought to evaluate the dosimetric feasibility of using stereotactic radiation therapy in polymetastatic disease in preparation for a phase 1 trial.

Methods and Materials

Five craniospinal computed tomography simulations were used to simulate 24 metastatic targets (n = 2 patients), 30 targets (n = 2 patients), and 50 targets (n = 1 patient) that were not present on the initial scan. Creation of radiation therapy plans was attempted for doses up to 30 Gy in 5 fractions, with de-escalation to 24 Gy/4, 18 Gy/3, 12 Gy/2, or 6 Gy/1 if not feasible based on standardized dose constraints. Plans were created using Raystation for delivery on linear accelerators using volumetric modulated arc therapy and validated using Mobius 3D.

Results

A stereotactic radiation therapy treatment plan was generated for each simulated patient. Dose constraints were met to a dose of 30 Gy in 5 fractions for the patients with 24 and 30 lesions. For the patient with 50 targets, dose de-escalation to 12 Gy in 2 fractions was required to meet lung constraints. Estimated beam-on time varied between 18 and 29 minutes per fraction of 6 Gy. Median D95 planning target volume dosimetry ranged from 96.6% to 97.7% of the prescription dose. The conformity index (R100) range was 0.89 to 0.95, and R50 range was 6.84 to 8.72.

Conclusions

Stereotactic radiation therapy treatment plans meeting standardized dose constraints could be created in the setting of 24 to 50 metastatic lesions using volumetric modulated arc therapy. This safety of this approach is being evaluated in a phase 1 trial (NCT04530513).

Stereotactic body radiotherapy for oligoprogressive lesions in metastatic castration-resistant prostate cancer patients during abiraterone/enzalutamide treatment

BACKGROUND

Metastasis-directed therapy (MDT) utilizing stereotactic body radiotherapy (SBRT) for oligoprogressive lesions could provide a delay in next-line systemic treatment (NEST) change while undergoing androgen receptor-targeted agents (ARTA) treatment. We evaluated prognostic factors for prostate cancer-specific survival (PCSS) and progression-free survival (PFS) to characterize patients receiving treatment with ARTA who may benefit from MDT for oligoprogressive lesions. The impact of MDT on delaying NEST and the predictive factors for NEST-free survival (NEST-FS) were also assessed.

MATERIALS AND METHODS

The clinical data of 54 metastatic castration-resistant prostate cancer patients with 126 oligoprogressive lesions receiving abiraterone (1 g/day) or enzalutamide (160 mg/day) before or after systemic chemotherapy were analyzed. A median of three lesions (range: 1-5) were treated with MDT. The primary endpoints were PCSS and PFS. The secondary endpoints were time to switch to NEST and NEST-FS.

RESULTS

The median follow-up time was 19.1 months. Univariate analysis showed that the number of oligoprogressive lesions treated with SBRT and the time between the start of ARTA treatment and oligoprogression were significant prognostic factors for PCSS, and the timing of ARTA treatment (before or after chemotherapy) and the prostate-specific antigen (PSA) response after MDT were significant prognostic factors for PFS. Multivariate analysis showed that early MDT for oligoprogressive lesions delivered less than 6 months after the beginning of ARTA and higher PSA levels after MDT were significant predictors of worse PCSS and PFS. The median total duration of ARTA treatment was 13.8 months. The median time between the start of ARTA treatment and the start of MDT for oligoprogressive lesions was 5.2 months, and MDT extended the ARTA treatment by 8.6 months on average. Thirty-two (59.3%) patients continued ARTA treatment after MDT. ARTA treatment after chemotherapy, early oligoprogression requiring MDT, and lower radiation doses for MDT were independent predictors of NEST-FS in multivariate analysis.

CONCLUSIONS

MDT for oligoprogressive lesions is effective and may provide several benefits compared to switching from ARTA treatment to NEST. Patients with early progression while on ARTAs and inadequate PSA responses after MDT have a greater risk of rapid disease progression and poor survival, which necessitates intensified treatment.

Revisiting a Null Hypothesis: Exploring the Parameters of Oligometastasis Treatment

PURPOSE

In the treatment of patients with metastatic cancer, the current paradigm states that metastasis-directed therapy does not prolong life. This paradigm forms the basis of clinical trial null hypotheses, where trials are built to test the null hypothesis that patients garner no overall survival benefit from targeting metastatic lesions. However, with advancing imaging technology and increasingly precise techniques for targeting lesions, a much larger proportion of metastatic disease can be treated. As a result, the life-extending benefit of targeting metastatic disease is becoming increasingly clear.

METHODS AND MATERIALS

In this work, we suggest shifting this qualitative null hypothesis and describe a mathematical model that can be used to frame a new, quantitative null. We begin with a very simple formulation of tumor growth, an exponential function, and illustrate how the same intervention (removing a given number of cells from the tumor) at different times affects survival. Additionally, we postulate where recent clinical trials fit into this parameter space and discuss the implications of clinical trial design in changing these quantitative parameters.

RESULTS

Our model shows that although any amount of cell kill will extend survival, in many cases the extent is so small as to be unnoticeable in a clinical context or is outweighed by factors related to toxicity and treatment time.

CONCLUSIONS

Recasting the null in these quantitative terms will allow trialists to design trials specifically to increase understanding of the circumstances (patient selection, disease burden, tumor growth kinetics) that can lead to improved overall survival when targeting metastatic lesions, rather than whether targeting metastases extends survival for patients with (oligo-) metastatic disease.

Postoperative solitary liver metastasis from esophageal squamous cell carcinoma achieving a clinical complete response to chemotherapy with cisplatin and 5-fluorouracil followed by stereotactic body radiotherapy: A case report

Treatment strategies for distant organ metastasis have changed markedly since the concept of oligometastasis was introduced. The perception that distant organ metastasis is a systemic disease and not eligible for local therapy is now a thing of the past. Therefore, the present report details a case of postoperative solitary liver metastasis from esophageal squamous cell carcinoma (ESCC), which achieved a clinical complete response to chemotherapy with cisplatin and 5-fluorouracil (5-FU) followed by stereotactic body radiotherapy (SBRT). A 76-year-old male patient underwent esophagectomy for lower thoracic ESCC. At 7 months after surgery, abdominal CT revealed a solitary hypovascular mass, 28 mm in size, in segment 7 of the liver. After three courses of chemotherapy with cisplatin and 5-FU, abdominal CT revealed that the liver mass had shrunk to 7 mm in size. SBRT was then administered with a 6 MV X-ray beam generated by a linear accelerator. A total dose of 50 Gy was given in 5 fractions of 10 Gy to the liver mass. At 1 month after SBRT, abdominal CT revealed that the liver mass had disappeared. The patient received no further adjuvant chemotherapy and had no recurrence at 18 months after diagnosis of liver metastasis and 13 months after SBRT.

Prognostic and Predictive Biomarkers in Oligometastatic Disease

Metastatic lesions are largely responsible for cancer-related deaths and are synonymous with a poor prognosis. However, this is not always true for patients with oligometastases whose disease may be amenable to curative-intent local therapies. It has been proposed that an "intermediate state" (oligometastasis) exists in between locoregional and advanced disease states; however, the clinical definition of oligometastasis varies, and there is limited understanding of how tumor biology differs between oligometastases and polymetastases. There is evidence that local therapies can extend survival in patients with oligometastases, yet patient selection for local intervention and/or systemic therapy remains a challenge. Prognostic and predictive biomarkers of oligometastatic disease are strongly needed to identify patient candidates most likely to gain survival benefit from local therapies and to aid in the incorporation of ablative treatments in the context of existing systemic therapies.

Radiation in the Treatment of Oligometastatic and Oligoprogressive Disease: Rationale, Recent Data, and Research Questions

The use of local ablative therapy or metastasis-directed therapy is an emerging management paradigm in oligometastatic and oligoprogressive cancer. Recent randomized evidence has demonstrated that stereotactic ablative radiotherapy (SABR) targeting all metastatic deposits is tolerable and can improve progression-free and overall survival. While SABR is noninvasive, minimally toxic, and generally safe, rare grade 5 events have been reported. Given this and recognizing the often-uncertain prognosis of patients with metastatic disease, equipoise persists regarding the therapeutic window within which to deploy SABR for this indication. Ongoing phase III trials are aimed at validating the demonstrated safety, tolerability, and survival benefits while also refining patient selection, possibly with the aid of novel biomarkers. This narrative review of the role of SABR in oligometastatic and oligoprogressive disease summarizes recent randomized evidence and ongoing clinical trials, discusses our rationale for treatment and key management principles, and posits that SABR should be considered the preferred modality for multisite, metastasis-directed ablative therapy.

Efficacy of PSMA PET-Guided Radiotherapy for Oligometastatic Castrate-Resistant Prostate Cancer

Purpose

To assess the outcome of radiotherapy (RT) to all PSMA ligand positive metastases for patients with castrate-resistant prostate cancer (mCRPC).

Patients and methods

A total of 42 patients developed oligometastatic mCRPC and received PSMA PET-guided RT of all metastases. The main outcome parameters were biochemical progression-free survival (bPFS), and second-line systemic treatment free survival (SST-FS).

Results

A total of 141 PSMA ligand-positive metastases were irradiated. The median follow-up time was 39.0 months (12-58 months). During the follow-up five out of 42 (11.9%) patients died of progressive mPCa. Five out of 42 (11.9%) patients showed no biochemical responses and presented with a PSA level ≥10% of the baseline PSA at first PSA level measurement after RT and were classified as non-responders. The median PSA level before RT was 4.79 ng/mL (range, 0.4-46.1), which decreased significantly to a median PSA nadir level of 0.39 ng/mL (range, <0.07-32.8; p=0.002). The median PSA level at biochemical progression after PSMA ligand-based RT was 2.75 ng/mL (range, 0.27-53.0; p=0.24) and was not significantly different (p=0.29) from the median PSA level (4.79 ng/mL, range, 0.4-46.1) before the PSMA ligand-based RT. The median bPFS was 12.0 months after PSMA ligand PET-based RT (95% CI, 11.2-15.8) and the median SST-FS was 15.0 months (95% CI, 14.0-21.5).

Conclusion

In well-informed and closely followed-up patients, PSMA PET-guided RT represents a viable treatment option for patients with oligometastatic mCRPC to delay further systemic therapies.

Prediction of Microscopic Metastases in Patients with Metachronous Oligo-Metastases after Curative Treatment of Non-Small Cell Lung Cancer: A Microsimulation Study

Simple Summary

Many patients with metachronous oligo-metastases in non-small cell lung cancer have their recurrences surgically removed, although the 5-year recurrence-free survival of this group is 16%. This does not provide any benefit for patients with additional undetected metastases. Therefore, we aim to find patient characteristics that are predictive for having additional undetected microscopic metastases. Based on a theoretical approach, we identified the size and number of detected oligo-metastases, as well as the presence of symptoms that are the most important risk predictors.

Abstract

Metachronous oligo-metastatic disease is variably defined as one to five metastases detected after a disease-free interval and treatment of the primary tumour with curative intent. Oligo-metastases in non-small cell lung cancer (NSCLC) are often treated with curative intent. However additional metastases are often detected later in time, and the 5-year survival is low. Burdensome surgical treatment in patients with undetected metastases may be avoided if patients with a high versus low risk of undetected metastases can be separated. Because there is no clinical data on undetected metastases available, a microsimulation model of the development and detection of metastases in 100,000 hypothetical stage I NSCLC patients with a controlled primary tumour was constructed. The model uses data from the literature as well as patient-level data. Calibration was used for the unobservable model parameters. Metastases can be detected by a scheduled scan, or an unplanned scan when the patient develops symptoms. The observable information at time of detection is used to identify subgroups of patients with a different risk of undetectable metastases. We identified the size and number of detected oligo-metastases, as well as the presence of symptoms that are the most important risk predictors. Based on these predictors, patients could be divided into a low-risk and a high-risk group, having a model-based predicted probability of 8.1% and 89.3% to have undetected metastases, respectively. Currently, the model is based on a synthesis of the literature data and individual patient-level data that were not collected for the purpose of this study. Optimization and validation of the model is necessary to allow clinical usability. We describe the type of data that needs to be collected to update our model, as well as the design of such a validation study.

Ablative radiation therapy to restrain everything safely treatable (ARREST): study protocol for a phase I trial treating polymetastatic cancer with stereotactic radiotherapy

BACKGROUND

Patients with polymetastatic cancer are most often treated with systemic therapy to improve overall survival and/or delay progression, with palliative radiotherapy reserved for sites of symptomatic disease. Stereotactic ablative radiotherapy (SABR) has shown promise in the treatment of oligometastatic disease, but the utility of SABR in treating all sites of polymetastatic disease has yet to be evaluated. This study aims to evaluate the maximally tolerated dose (MTD) of SABR in patients with polymetastatic disease.

METHODS

Up to 48 patients with polymetastatic cancer (> 10 sites) will be enrolled on this phase I, modified 3 + 3 design trial. Eligible patients will have exhausted (or refused) standard systemic therapy options. SABR will be delivered as an escalating number of weekly fractions of 6 Gy, starting at 6 Gy × 2 weekly fractions (dose level 1). The highest dose level (dose level 4) will be 6 Gy × 5 weekly fractions. Feasibility and safety of SABR will be evaluated 6 weeks following treatment using a composite endpoint of successfully completing treatment as well as toxicity outcomes.

DISCUSSION

This study will be the first to explore delivering SABR in patients with polymetastatic disease. SABR will be planned using the guiding principles of: strict adherence to dose constraints, minimization of treatment burden, and minimization of toxicity. As this represents a novel use of radiotherapy, our phase I study will allow for careful selection of the MTD for exploration in future studies.

TRIAL REGISTRATION

This trial was prospectively registered in ClinicalTrials.gov as NCT04530513 on August 28, 2020.

Pulmonary metastasectomy: limits to credibility

Lung metastases are a common site of spread for many malignant tumours. Pulmonary metastasectomy has been practiced for many years for sarcomas and is now becoming increasingly frequently advocated for patients with many other tumours, especially colorectal cancer. In this article we argue that this procedure is one framed by therapeutic opportunity and not supported by strong evidence. It is potentially harmful and may not be effective. Our argument is based on several important issues: (I) the vagueness of the concept of "oligometastases" and its biological implausibility; (II) the flaws in the often-cited observational evidence, especially selection bias; (III) the lack of any reliable randomised trial evidence of improved survival but evidence of harm; (IV) the failure of strategies to detect metastases earlier to influence overall survival. The introduction of stereotactic radiotherapy and image-guided thermal ablation have made the urge to treat lung metastases stronger but without any good evidence to justify their use. We acknowledge the problems of carrying out randomised trials when there is a clear lack of equipoise in the clinical teams involved but believe that there is an ethical need to do so. Many patients are probably being given false hope of cure or prolonged survival but are at risk of harm from pulmonary metastasectomy or ablation. It is possible that a few patients may benefit but without better evidence we do not know which, if any, do.

Successful bronchial arterial infusion chemotherapy combined with radiotherapy for an endobronchial metastasis after resection of small cell lung cancer

Bronchial arterial infusion (BAI) chemotherapy has been reported to be an effective treatment option for centrally located early-stage squamous cell lung cancer (SCC) and has a favourable response rates for patients with stage III or IV or recurrent non-small cell lung cancer (NSCLC) without distant metastases who cannot tolerate standard chemotherapy. Here, we report a case of an 83-year-old male with a solitary polypoid endobronchial metastatic tumour in the left main bronchus one year and 10 months after video-assisted thoracoscopic surgery (VATS) combined segmentectomy (left S6 + S8a) for small cell lung cancer (SCLC), pT1bN0. He was treated with BAI of 100 mg of cis-Diamminedichloroplatinum/cisplatin (CDDP), followed by thoracic radiotherapy (56 Gy in 28 fractions). There was no recurrence for 2.5 years. BAI chemotherapy combined with radiotherapy seemed to be an effective salvage option for the treatment of solitary endobronchial metastases of SCLC in patients unfit for standard chemoradiotherapy.

Stereotactic radiotherapy to oligoprogressive lesions detected with 68Ga-PSMA-PET/CT in castration-resistant prostate cancer patients

PURPOSE

We assessed the outcomes of stereotactic body radiotherapy (SBRT) to treat oligoprogressive castration-resistant prostate cancer (CRPC) patients with ≤5 lesions using gallium prostate-specific membrane antigen-positron emission tomography (⁶⁸Ga-PSMA-PET/CT).

METHODS

The clinical data of 67 CRPC patients with 133 lesions treated with ⁶⁸Ga-PSMA-PET/CT-based SBRT were retrospectively analyzed. All of the patients had oligoprogressive disease during androgen-deprivation therapy (ADT). The prognostic factors for overall- (OS) and progression-free survival (PFS) and the predictive factors for switching to next-line systemic treatment (NEST) and NEST-free survival (NEST-FS) were analyzed.

RESULTS

With a median follow-up of 17.5 months, the 2-year overall survival (OS) and PFS rates were 86.9% and 34.4%, respectively. The PSA response was observed in 49 patients (73.1%). Progression was observed in 37 patients (55.2%) at a median of 11.0 months following SBRT. A total of 45 patients (67.2%) remained on ADT after SBRT, and 22 patients (32.8%) had a NEST change at a median of 16.4 months after metastasis-directed treatment (MDT). Patients with a NEST change had higher post-SBRT PSA values and fewer PSA nadirs after MDT than their counterparts. In multivariate analysis, higher pre-SBRT PSA values were the only significant predictor for worse OS and NEST-FS, and no significant factor was found for PFS. No serious acute or late toxicities were observed.

CONCLUSION

This study demonstrated the feasibility of MDT using SBRT to treat oligoprogressive lesions by ⁶⁸Ga-PSMA-PET/CT in CRPC patients is efficient and well-tolerated, prolonging the effectiveness of ADT by delaying NEST.

Trends in Primary Surgical Resection and Chemotherapy for Metastatic Colorectal Cancer, 2000-2016

BACKGROUND

When, whether, and in whom primary tumor resection (PTR) for patients with metastatic colorectal cancer (CRC) is indicated remains unknown. With advances in multiagent systemic chemotherapy, PTR may be undertaken less frequently. The aim of this study was to obtain estimates of changes in the utilization of PTR and chemotherapy for metastatic CRC.

METHODS

Patients diagnosed with metastatic CRC between 2000 and 2016 were identified from Surveillance Epidemiology, and End Results (SEER) registry. Multivariable logistic regression defined odds of undergoing PTR. The analysis was also stratified by primary site (colon vs. rectum), age (younger than 50 vs. 50 y and older), and whether patients also underwent resection of metastatic sites (yes vs. no). The secondary endpoint of interest was the receipt of any chemotherapy, also assessed by multivariable logistic regression.

RESULTS

Among 99,835 patients with metastatic CRC, 55,527 (55.7%) underwent PTR. The odds of undergoing PTR decreased with a later year of diagnosis, with patients diagnosed in 2016 being 61.1% less likely to undergo surgery than those diagnosed in 2000 (adjusted odds ratio=0.39, 95% confidence interval: 0.36-0.42, P<0.0001; absolute percentage: 62.3% to 43.8%). Similar trends by year for PTR were observed among each of the subgroups, although patients with colon primary, young adults (age younger than 50 y), and patients also undergoing metastasectomy were more likely to undergo PTR (P<0.001 for all). In contrast, the odds of receiving chemotherapy increased dramatically with a later year of diagnosis (adjusted odds ratio=2.21, 95% confidence interval: 2.04-2.40, P<0.0001).

CONCLUSIONS

From 2000 to 2016, there was a sharp decline in the rate of PTR for patients with metastatic CRC, while the use of chemotherapy increased over the same period. Prospective studies are needed to define the optimal local treatment for patients with metastatic CRC.

Characterization of Oligometastatic Disease in a Real-World Nationwide Cohort of 3447 Patients With de Novo Metastatic Breast Cancer

Background

Observational studies in metastatic breast cancer (MBC) show that long-term overall survival (OS) is associated with limited tumor burden, or oligo-MBC (OMBC). However, a uniform definition of OMBC is lacking. In this real-world nationwide cohort, we aimed to define the optimal OMBC threshold and factors associated with survival in patients with OMBC.

Methods

3535 patients aged younger than 80 years at diagnosis of de novo MBC in the Netherlands between January 2000 and December 2007 were included. Detailed clinical, therapy, and outcome data were collected from medical records of a sample of the patients. Using inverse-sampling-probability weighting, the analysis cohort (n = 3447) was constructed. We assessed OS according to number of metastases at diagnosis to determine the optimal OMBC threshold. Next, we applied Cox regression models with inverse-sampling-probability weighting to study associations with OS and progression-free survival in OMBC. All statistical tests were 2-sided.

Results

Compared with more than 5 distant metastases, adjusted hazard ratios for OS (with 95% confidence interval [CI] based on robust standard errors) for 1, 2-3, and 4-5 metastases were 0.70 (95% CI = 0.52 to 0.96), 0.63 (95% CI = 0.45 to 0.89), and 0.91 (95% CI = 0.61 to 1.37), respectively. Ten-year OS estimates for patients with no more than 3 vs more than 3 metastases were 14.9% and 3.4% (P < .001). In multivariable analyses, premenopausal andperimenopausal status, absence of lung metastases, and local therapy of metastases (surgery and/or radiotherapy) added to systemic therapy were statistically significantly associated with better OS and progression-free survival in OMBC, independent of local therapy of the primary tumor.

Conclusion

OMBC defined as MBC limited to 1-3 metastases was associated with favorable OS. In OMBC, local therapy of metastases was associated with better OS, particularly if patients were premenopausal or perimenopausal without lung metastases.

Benefits of local consolidative treatment in oligometastases of solid cancers: a stepwise-hierarchical pooled analysis and systematic review

We conducted a meta-analysis of articles published in PubMed, MEDLINE, EMBASE, and Cochrane library to investigate the effectiveness of local consolidative therapy (LCT) against oligometastases. Data from randomized controlled trials (RCTs), balanced studies, and all studies combined were analyzed in a hierarchical manner. Pooled analyses of 31 studies (including seven randomized trials) investigating the effectiveness of LCT on overall survival revealed odds ratios of 3.04, 2.56, and 1.41 for all studies, balanced studies, and RCTs, respectively (all p < 0.05). The benefit of LCT was more prominent in patients with non-small cell lung and colorectal cancers than in those with prostate and small cell lung cancers. Moreover, the benefit of LCT was smaller in patients with high metastatic burdens (p = 0.054). In four of 12 studies with available information, additional grade ≥3 toxicities due to LCTs were reported. Overall, LCT is beneficial for patients with oligometastases, although such benefits are less evident in RCTs than in observational studies. Appropriate LCTs should be carefully selected considering their feasibility, disease type, and metastatic burden.

Intracranial Grade II Meningioma Oligometastatic to the Cervical Spine

For intracranial meningiomas that metastasize extracranially, an oligometastatic state exists that is intermediate between incurable, widely metastatic disease and non-metastatic curable disease. Similar to oligometastatic cancer, aggressive local treatment of meningioma oligometastases is warranted, as it may be curable. We present a patient with multiply recurrent intracranial meningiomas over 19 years, with a transformation from grade I to grade II histology, with oligometastatic disease to the C5 vertebral body. Three years following definitive spinal stereotactic radiosurgery, she remains without evidence of other metastatic diseases. Our case highlights the oncologic concept that metastatic meningioma need not be widely disseminated and provides the clinical rationale for aggressive local treatment of an oligometastatic meningioma.

The Role of Radiation Therapy in the Older Patient

PURPOSE OF REVIEW

Older patients represent a unique subgroup of the cancer patient population for which the role of radiation therapy (RT) requires special consideration. This review will discuss many of these considerations as well as various radiation treatment techniques in the context of a variety of disease sites.

RECENT FINDINGS

Several recent studies give insight into the management of older cancer patients considering their age, performance status, comorbid conditions, quality of life, genetics, cost, and individual goals. RT plays an evolving and pivotal role in providing optimal care for this population. Recent advances in RT technique allow for more precise treatment delivery and reduced toxicity. Studies evaluating the use of radiation therapy in breast, brain, lung, prostate, rectal, pancreatic, esophageal, and oligometastatic cancer are summarized and discussed in the context of treating the older patient population. Individual age, performance and functional status, comorbid conditions, and patients' objectives and goals should all be considered when presenting treatment options for older patients and age alone should not disqualify patients from curative intent treatments. When possible, hypofractionated courses should be utilized as outcomes are often equivalent and toxicities are reduced. In many cases, RT may be preferable to other treatment options due to decreased toxicity profile and acceptable disease control.

Treatment of advanced nonsmall cell lung cancer: First line, maintenance and second line - Indian consensus statement update

The management of advanced nonsmall cell lung cancer (NSCLC) patients is becoming increasingly complex with the identification of driver mutations/rearrangements and development/availability of appropriate targeted therapies. In 2017, an expert group of medical oncologists with expertise in treating lung cancer used data from published literature and experience to arrive at practical consensus recommendations on treatment of advanced NSCLC for use by the community oncologists. This was published subsequently in the Indian Journal of Cancer with a plan to be updated annually. The present document is an update to the 2017 document.

Metastatic salivary gland carcinoma: A role for stereotactic body radiation therapy? A study of AIRO-Head and Neck working group

OBJECTIVES

The role of radiotherapy (RT) for oligometastases is currently established in different oncological settings but data on salivary gland cancer (SGC) are lacking. We evaluated the role of RT in oligometastatic SGC patients, focusing on stereotactic body radiation therapy (SBRT).

MATERIALS AND METHODS

We performed a retrospective, multicentric study of oligometastatic SGC treated with palliative RT or SBRT. Endpoints included response evaluation and local control (LC).

RESULTS

Between 2006 and 2016, 64 patients were collected from 9 Italian Cancer Centers, on behalf of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) Head and Neck Working Group. 37 patients (57.8%) were suffering from adenoid cystic carcinoma (ACC) and 27 patients (42.2%) had non-ACC. Thirty-four patients underwent palliative RT (53,1%), and 30 received SBRT (46,9%). Most common metastatic sites were bone for palliative RT and lung for SBRT. Among patients treated with SBRT, an objective response or a stability was observed in all treated lesions. After a median follow-up of 29.2 months (range 2.3-117.1), LC at 12 months was 57.5% for patients treated with SBRT and was higher in ACC subgroup.

CONCLUSION

We confirmed the potential role of SBRT in the management of oligometastatic SGC patients to control limited burden of disease considering the absence of effective systemic therapies.

Long-term survival of two patients with pancreatic cancer after resection of liver and lung oligometastases: a case report

Background

The efficacy of resection of pancreatic cancer metastases has not been established. We here report two patients with long-term survival after resection of lung and liver metastases.

Case presentation

The first patient underwent distal pancreatectomy for pancreatic cancer. One year later, she underwent partial hepatectomy for a single liver metastasis. She subsequently underwent pulmonary resections 7, 7.5, 9, and 10 years later for pulmonary metastases from pancreatic cancer. Thus, this patient underwent five surgeries for metastases, one for a liver metastasis and four for lung metastases. All of the tumors were pathologically diagnosed as metastatic pancreatic cancer. She is currently alive without new recurrence 10 years after the initial diagnosis. The second patient underwent pancreaticoduodenectomy for pancreatic cancer. Four years later, she underwent a thoracoscopic partial resection for lung metastasis. The tumor was similar to the pancreatic cancer on pathological examination. She is currently alive without new recurrences 6 years after the initial diagnosis.

Conclusion

Long-term survival can be achieved in some patients with pancreatic cancer by resection of metachronous liver or lung metastases.

Role of Surgical Intervention in Unresectable Non-Small Cell Lung Cancer

With the development of systemic treatments with high response rates, including tyrosine kinase inhibitors and immune checkpoint inhibitors, some patients with unresectable lung cancer now have a chance to undergo radical resection after primary treatment. Although there is no general consensus regarding the definition of “unresectable” in lung cancer, the term “resectable” refers to technically resectable and indicates that resection can provide a favorable prognosis to some extent. Unresectable lung cancer is typically represented by stage III and IV disease. Stage III lung cancer is a heterogeneous disease, and in some patients with technically resectable non-small cell lung cancer (NSCLC), multimodality treatments, including induction chemoradiotherapy followed by surgery, are the treatments of choice. The representative surgical intervention for unresectable stage III/IV NSCLC is salvage surgery, which refers to surgical treatment for local residual/recurrent lesions after definitive non-surgical treatment. Surgical intervention is also used for an oligometastatic stage IV NSCLC. In this review, we highlight the role of surgical intervention in patients with unresectable NSCLC, for whom an initial complete resection is technically difficult. We further describe the history of and new findings on salvage surgery for unresectable NSCLC and surgery for oligometastatic NSCLC.

Adapting to the motion of multiple independent targets using multileaf collimator tracking for locally advanced prostate cancer: Proof of principle simulation study

PURPOSE

For patients with locally advanced cancer, multiple targets are treated simultaneously with radiotherapy. Differential motion between targets can compromise the treatment accuracy, yet there are currently no methods able to adapt to independent target motion. This study developed a multileaf collimator (MLC) tracking algorithm for differential motion adaptation and evaluated it in simulated treatments of locally advanced prostate cancer.

METHODS

A multi-target MLC tracking algorithm was developed that consisted of three steps: (a) dividing the MLC aperture into two possibly overlapping sections assigned to the prostate and lymph nodes, (b) calculating the ideally shaped MLC aperture as a union of the individually translated sections, and (c) fitting the MLC positions to the ideal aperture shape within the physical constraints of the MLC leaves. The multi-target tracking method was evaluated and compared with two existing motion management methods: single-target tracking and no tracking. Treatment simulations of six locally advanced prostate cancer patients with three prostate motion traces were performed for all three motion adaptation methods. The geometric error for each motion adaptation method was calculated using the area of overexposure and underexposure of each field. The dosimetric error was estimated by calculating the dose delivered to the prostate, lymph nodes, bladder, rectum, and small bowel using a motion-encoded dose reconstruction method.

RESULTS

Multi-target MLC tracking showed an average improvement in geometric error of 84% compared to single-target tracking, and 83% compared to no tracking. Multi-target tracking maintained dose coverage to the prostate clinical target volume (CTV) D98% and planning target volume (PTV) D95% to within 4.8% and 3.9% of the planned values, compared to 1.4% and 0.7% with single-target tracking, and 20.4% and 31.8% with no tracking. With multi-target tracking, the node CTV D95%, PTV D90%, and gross tumor volume (GTV) D95% were within 0.3%, 0.6%, and 0.3% of the planned values, compared to 9.1%, 11.2%, and 21.1% for single-target tracking, and 0.8%, 2.0%, and 3.2% with no tracking. The small bowel V57% was maintained within 0.2% to the plan using multi-target tracking, compared to 8% and 3.5% for single-target tracking and no tracking, respectively. Meanwhile, the bladder and rectum V50% increased by up to 13.6% and 5.2%, respectively, using multi-target tracking, compared to 2.7% and 1.9% for single-target tracking, and 11.2% and 11.5% for no tracking.

CONCLUSIONS

A multi-target tracking algorithm was developed and tracked the prostate and lymph nodes independently during simulated treatments. As the algorithm optimizes for target coverage, tracking both targets simultaneously may increase the dose delivered to the organs at risk.

Evaluation of Definitive Stereotactic Body Radiotherapy and Outcomes in Adults With Extracranial Oligometastasis

IMPORTANCE

The outcomes and factors that influence survival in patients with oligometastasis (OM) are not well understood and have not been well described in large-scale studies.

OBJECTIVE

To evaluate overall progression-free survival (PFS), widespread progression (WSP) outcomes, and survival factors from a pooled data set of 1033 patients with OM treated with stereotactic body radiotherapy (SBRT).

DESIGN, SETTING, AND PARTICIPANTS

Case series from January 1, 2008, to December 31, 2016. The dates of analysis were April 2019 to May 2020. The setting was multi-institutional tertiary care hospitals. Participants were consecutive patients with 5 or fewer extracranial OMs whose primary tumor was treated curatively.

EXPOSURE

Definitive SBRT.

MAIN OUTCOMES AND MEASURES

Overall survival (OS), progression-free survival, rate of WSP, patterns of failure, and factors altering OS.

RESULTS

In the largest international OM case series to date (1033 participants) (mean age, 68.0 years [range, 18.0-94.3 years]; 601 [58.2%] men), 1416 SBRT courses were delivered to patients with 1 OM (596 [57.7%]), 2 OMs (245 [23.7%]), 3 OMs (105 [10.2%]), 4 OMs (55 [5.3%]), and 5 OMs (32 [3.1%]). The median follow-up was 24.1 months (range, 0.3-104.7 months), and the median OS was 44.2 months (95% CI, 39.2-48.8 months). The median PFS was 12.9 months (95% CI, 11.6-14.2 months), and the median time to WSP was 42.5 months (95% CI, 36.8-53.5 months). The OS rates were 84.1% (95% CI, 81.7%-86.2%) at 1 year, 56.7% (95% CI, 53.0%-60.2%) at 3 years, and 35.2% (95% CI, 30.1%-40.3%) at 5 years. The 3-year OS, PFS, and WSP rates were 56.7% (95% CI, 53.0%-60.2%), 23.0% (95% CI, 20.2%-25.9%), and 45.2% (95% CI, 41.4%-48.9%), respectively. The 5-year OS, PFS, and WSP rates were 35.2% (95% CI, 30.1%-40.3%), 14.8% (95% CI, 11.9%-17.9%), and 54.5% (95% CI, 49.8%-59.2%), respectively. At the time of first progression, 342 patients (33.1%) had recurrence of OM disease, and 230 patients (22.3%) underwent subsequent ablative therapies to all known metastatic sites. Multivariable analyses identified primary tumor type (hazard ratio [HR], 3.73; 95% CI, 1.75-7.94; P < .001 for breast; 5.75; 95% CI, 2.88-11.46; P < .001 for colorectal; 4.67; 95% CI, 2.12-10.31; P < .001 for kidney; 10.61; 95% CI, 5.36-20.99; P < .001 for lung; and 12.00; 95% CI, 6.06-23.76; P < .001 for other [with prostate being the reference group]), metachronous OM presentation more than 24 months since initial diagnosis (HR, 0.63; 95% CI, 0.49-0.80; P < .001), metastases confined to the lung only (HR, 0.58; 95% CI, 0.48-0.72; P < .001), and nodal or soft-tissue metastases only (HR, 0.49; 95% CI, 0.26-0.90; P = .02) as survival factors. Sixty-six (6.4%) grade 3 or higher toxic effects were observed, including 1 (0.1%) grade 5 event.

CONCLUSIONS AND RELEVANCE

This study found favorable long-term OS and WSP rates associated with extracranial OM ablated with SBRT; however, modest PFS rates were observed. A substantial proportion of patients with OM developed progressive disease and were treated with local ablation. Factors that can inform clinical decision-making and clinical trial design include primary tumor type, a metachronous presentation more than 24 months since diagnosis, and the site of OM presentation.

PEG-PLGA nanospheres loaded with nanoscintillators and photosensitizers for radiation-activated photodynamic therapy

Photodynamic Therapy (PDT) is an effective treatment modality for cancers, with Protoporphyrin IX (PPIX)-based PDT being the most widely used to treat cancers in patients. However, PDT is limited to superficial, thin (few mm in depth) lesions that can be accessed by visible wavelength light. Interstitial light-delivery strategies have been developed to treat deep-seated lesions (i.e. prostate cancer). The most promising of these are X-ray-induced scintillation nanoparticles, which have shown potential benefits for PDT of deep-seated tumors. Herein, the design and use of a new nanoscintillator-based radiation-activated PDT (radioPDT) system is investigated in the treatment of deep-seated tumors. Poly(ethylene glycol) methyl ether-block-poly(lactide-co-glycolide) (PEG-PLGA) nanospheres were loaded with a scintillator (LaF₃:Ce³⁺) and photosensitizer (PPIX) to effect radioPDT. UV-Vis spectroscopy and electron microscopy studies demonstrated efficient encapsulation of nanoscintillators and PPIX (>90% efficiency) into the PEG-PLGA nanospheres. The nanoparticles were uniform in size and approximately 100 nm in diameter. They were highly stable and functional for up to 24 h under physiological conditions and demonstrated slow release kinetics. In vitro and in vivo toxicity studies showed no appreciable drug toxicity to human skin fibroblast (GM38), prostate cancer cells (PC3), and to C57/BL mice. Cell uptake studies demonstrated accumulation of the nanoparticles in the cytoplasm of PC3 cells. When activated, fluorescent resonant energy transfer (FRET) was evident via fluorescent spectroscopy and singlet oxygen yield. Determination of stability revealed that the nanoparticles were stable for up to 4 weeks. The nanoparticle production was scaled-up with no change in properties. This nanoparticle represents a unique, optimally designed therapeutic and diagnostic agent (theranostic) agent for radioPDT with characteristics capable of potentially augmenting radiotherapy for deep-seated tumors and integrating into current cancer radiotherapy.

Prognostic factors in patients with oligometastatic breast cancer - A systematic review

AIM

Oligometastatic breast cancer (OMBC) is a disease-entity with potential for long-term remission in selected patients. Those with truly limited metastatic load (rather than occult widespread metastatic disease) may benefit from multimodality treatment including local ablative therapy of distant metastases. In this systematic review, we studied factors associated with long-term survival in patients with OMBC.

METHODS

Eligible studies included patients with OMBC who received a combination of local and systemic therapy as multimodal approach and reported overall survival (OS) or progression-free survival (PFS), or both. The Quality in Prognosis Studies (QUIPS) tool was used to assess the quality of each included study. Independent prognostic factors for OS and/or PFS are summarized.

RESULTS

Of 1271 screened abstracts, 317 papers were full-text screened and twenty studies were included. Eleven of twenty studies were classified as acceptable quality. Definition of OMBC varied between studies and mostly incorporated the number and/or location of metastases. The 5-year OS ranged between 30 and 79% and 5-year PFS ranged between 25 and 57%. Twelve studies evaluated prognostic factors for OS and/or PFS in multivariable models. A solitary metastasis, >24 months interval between primary tumor and OMBC, no or limited involved axillary lymph nodes at primary diagnosis, and hormone-receptor positivity were associated with better outcome. HER2-positivity was associated with worse outcome, but only few patients received anti-HER2 therapy.

CONCLUSIONS

OMBC patients with a solitary distant metastasis and >24 months disease-free interval have the best OS and may be optimal candidates to consider a multidisciplinary approach.

Surgical management of oligometastatic disease in gastric cancer

A distinctive subset of metastatic gastric cancer (MGC) is oligometastatic disease (OMD), which is characterized by metastatic lesions limited in number and location. Although growing evidence mainly based on retrospective analysis or single center case series has shown favorable prognosis in the management of OMD in gastric cancer with aggressive local treatment, no existing guidelines explicitely address the definition of OMD and there are still controversial opinions on how to proceed in a new era with more effective systemic therapy selection. In this review, we present the current advances and evidence as well as controversial on the management of OMD in MGC, including the definition, diagnosis, local aggressive treatments especially surgery, prognostic factors, current ongoing randomized clinical studied as well as challenges facing the field.

Stereotactic body radiotherapy for adrenal oligometastasis in lung cancer patients

OBJECTIVE

To report our experience on stereotactic body radiotherapy (SBRT) in adrenal metastases from lung cancer.

METHODS

37 oligometastatic lung cancer patients with 38 adrenal metastases submitted to SBRT were retrospectively analyzed. SBRT was delivered by volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT). Primary study end point was local recurrence-free survival (LR-FS) and secondary end points were distant-progression free survival (d-PFS) and overall survival (OS).

RESULTS

Median age was 67 years and primary tumor was non-small-cell lung cancer in 27 (73%) and small-cell lung cancer in 10 (27%) patients. Adrenal metastases were in the left side in 66% cases. Median prescribed dose was 30 Gy in 5 fractions for a median biologically equivalent dose (α/β ratio 10  Gy, BED10) of 48 Gy. Most patients (62%) were submitted to SBRT alone, while the others (38%) received chemo-, immune- or target- therapies. Median follow-up was 10.5 months, median OS 16 months and median d-PFS 3 months. 27 (70%) patients obtained a local control with a median LR-FS of 32 months. LR-FS was significantly related to BED10 with a better LC with BED10 ≥72 Gy, 1- and 2 year LR-FS rates were 54.1±11.6% and 45±12.7% vs 100 and 100% for BED ≤59.5 Gy and BED ≥72 Gy, respectively (p = 0.05). There was no severe toxicity.

CONCLUSION

SBRT was effective and safe in lung cancer adrenal metastases. A dose-response relationship was found between BED10 >72 Gy and better local control. No significant toxicity was registered thanks to the respect of dose constraints and suspension of chemo- and target-therapies.

ADVANCES IN KNOWLEDGE

SBRT with a BED10 >72 Gy is an effective treatment for adrenal oligometastatic lung cancer patients.

The Movember Prostate Cancer Landscape Analysis: an assessment of unmet research needs

Prostate cancer is a heterogeneous cancer with widely varying levels of morbidity and mortality. Approaches to prostate cancer screening, diagnosis, surveillance, treatment and management differ around the world. To identify the highest priority research needs across the prostate cancer biomedical research domain, Movember conducted a landscape analysis with the aim of maximizing the effect of future research investment through global collaborative efforts and partnerships. A global Landscape Analysis Committee (LAC) was established to act as an independent group of experts across urology, medical oncology, radiation oncology, radiology, pathology, translational research, health economics and patient advocacy. Men with prostate cancer and thought leaders from a variety of disciplines provided a range of key insights through a range of interviews. Insights were prioritized against predetermined criteria to understand the areas of greatest unmet need. From these efforts, 17 research needs in prostate cancer were agreed on and prioritized, and 3 received the maximum prioritization score by the LAC: first, to establish more sensitive and specific tests to improve disease screening and diagnosis; second, to develop indicators to better stratify low-risk prostate cancer for determining which men should go on active surveillance; and third, to integrate companion diagnostics into randomized clinical trials to enable prediction of treatment response. On the basis of the findings from the landscape analysis, Movember will now have an increased focus on addressing the specific research needs that have been identified, with particular investment in research efforts that reduce disease progression and lead to improved therapies for advanced prostate cancer.

The Movember global Landscape Analysis Committee (LAC) was established to act as an independent group of experts across urology, medical oncology, radiation oncology, radiology, pathology, translational research, health economics and patient advocacy to identify the highest priority research needs across the prostate cancer biomedical research domain. Findings from the landscape analysis illustrate the research priorities in prostate cancer and will enable Movember to focus on specific needs, with particular investment in research to reduce disease progression and improve therapies for advanced prostate cancer.

Stereotactic Ablative Radiotherapy for the Comprehensive Treatment of Oligometastatic Cancers: Long-Term Results of the SABR-COMET Phase II Randomized Trial

PURPOSE

The oligometastatic paradigm hypothesizes that patients with a limited number of metastases may achieve long-term disease control, or even cure, if all sites of disease can be ablated. However, long-term randomized data that test this paradigm are lacking.

METHODS

< .20 indicates a positive trial). Secondary end points included progression-free survival (PFS), toxicity, and quality of life (QOL). Herein, we present long-term outcomes from the trial.

RESULTS

= .001). There were no new grade 2-5 adverse events and no differences in QOL between arms.

CONCLUSION

With extended follow-up, the impact of SABR on OS was larger in magnitude than in the initial analysis and durable over time. There were no new safety signals, and SABR had no detrimental impact on QOL.

Harnessing the potential of multimodal radiotherapy in prostate cancer

Radiotherapy in combination with androgen deprivation therapy (ADT) is a standard treatment option for men with localized and locally advanced prostate cancer. However, emerging clinical evidence suggests that radiotherapy can be incorporated into multimodality therapy regimens beyond ADT, in combinations that include chemotherapy, radiosensitizing agents, immunotherapy and surgery for the treatment of men with localized and locally advanced prostate cancer, and those with oligometastatic disease, in whom the low metastatic burden in particular might be treatable with these combinations. This multimodal approach is increasingly recognized as offering considerable clinical benefit, such as increased antitumour effects and improved survival. Thus, radiotherapy is becoming a key component of multimodal therapy for many stages of prostate cancer, particularly oligometastatic disease.

Novel Dose Escalation Approaches for Stereotactic Body Radiotherapy to Adrenal Oligometastases: A Single-Institution Experience

OBJECTIVES

The role of local disease control in the oligometastatic setting is evolving. Stereotactic body radiation therapy (SBRT) is a noninvasive treatment option for oligometastases; however, using ablative radiation doses for adrenal metastases raises concern given the proximity to radiosensitive organs. Novel treatment techniques may allow for selective dose escalation to improve local control (LC) while minimizing dose to nearby critical structures.

MATERIALS AND METHODS

We retrospectively reviewed patients with adrenal oligometastases treated with SBRT from 2013 to 2018. LC, disease-free survival, and overall survival were estimated using Kaplan-Meier methods. Predictors of outcomes were evaluated by log-rank and Cox proportional hazard analyses.

RESULTS

We identified 45 adrenal oligometastases in 41 patients treated with SBRT. The median age at treatment was 67 years (range, 40 to 80). The most common primary histologies were non-small cell lung cancer (51%), renal cell carcinoma (24%), and small cell lung cancer (10%). The median prescription dose was 50 Gy (range, 25 to 60 Gy), with 30 (67%) lesions receiving ≥50 Gy and 14 (31%) receiving 60 Gy. In total, 26 (58%) lesions received a simultaneous-integrated boost. Of the 42 treatment simulations, 26 (62%) were supine, 5 (12%) prone, and 11 (26%) in the left lateral decubitus position. At a median follow-up of 10.5 months, there were 3 local failures with a 12-month LC rate of 96%.

CONCLUSIONS

Adrenal SBRT for oligometastatic disease is a feasible, noninvasive option with excellent LC and minimal toxicity. Lesions in close proximity to radiosensitive organs may benefit from dynamic patient positioning and selective simultaneous-integrated boost techniques to allow for dose escalation, while also limiting toxicity risks.

Stereotactic ablative radiotherapy for the comprehensive treatment of 1-3 Oligometastatic tumors (SABR-COMET-3): study protocol for a randomized phase III trial

Background

A recent randomized phase II trial evaluated stereotactic ablative radiotherapy (SABR) in a group of patients with a small burden of oligometastatic disease (mostly with 1–3 metastatic lesions), and found that SABR was associated with a significant improvement in progression-free survival and a trend to an overall survival benefit, supporting progression to phase III randomized trials.

Methods

Two hundred and ninety-seven patients will be randomized in a 1:2 ratio between the control arm (consisting of standard of care [SOC] palliative-intent treatments), and the SABR arm (consisting of SOC treatment + SABR to all sites of known disease). Randomization will be stratified by two factors: histology (prostate, breast, or renal vs. all others), and disease-free interval (defined as time from diagnosis of primary tumor until first detection of the metastases being treated on this trial; divided as ≤2 vs. > 2 years). The primary endpoint is overall survival, and secondary endpoints include progression-free survival, cost effectiveness, time to development of new metastatic lesions, quality of life (QoL), and toxicity. Translational endpoints include assessment of circulating tumor cells, cell-free DNA, and tumor tissue as prognostic and predictive markers, including assessment of immunological predictors of response and long-term survival.

Discussion

This study will provide an assessment of the impact of SABR on survival, QoL, and cost effectiveness to determine if long-term survival can be achieved for selected patients with 1–3 oligometastatic lesions.

Trial registration

Clinicaltrials.gov identifier: NCT03862911. Date of registration: March 5, 2019,

Oligorecurrence Non-small Cell Lung Cancer After Failure of First-Line Chemotherapy: Computed Tomography-Guided 125I Seed Implantation vs. Second-Line Chemotherapy

Purpose: To compare the efficacy and safety of computed tomography (CT)–guided ¹²⁵I seed implantation with second-line chemotherapy in treatment of oligorecurrence non–small cell lung cancer after failure of first-line chemotherapy.

Methods: Data of oligorecurrence non–small cell lung cancer patients after failure of first-line chemotherapy at two institutions were retrospectively reviewed from January 2013 to July 2018. A total of 53 patients who received the treatment of ¹²⁵I seed implantation or second-line chemotherapy were eligible for this study. In group A, 25 patients, 84 lesions, received CT-guided permanent ¹²⁵I seed implantation, whereas in group B, 28 patients, 96 lesions, received second-line chemotherapy. The outcomes were measured in terms of disease control rate, overall survival, quality of life, and complications.

Results: The median follow-up period was 13 months (range, 5–42 months). Disease control rate in group A was higher than that in group B (70.8 vs. 42.3%, P = 0.042) at 6 months after treatment. The median overall survival was 12.8 months (95% confidence interval, 10.5–15.1 months) in group A and 15.2 months (95% confidence interval, 12.2–18.2 months) in group B, with no significant difference (P = 0.847). Since the fourth month, the number of patients in group A with a non-decreasing Karnofsky Performance Scale score was more than that in group B (P < 0.05). The incidence of grade 3 or higher complications especially hematologic toxicity in group A was significantly lower than that in group B (P < 0.05).

Conclusion: Radioactive ¹²⁵I seed implantation is safe and feasible in selected non–small cell lung cancer patients with oligorecurrence after failure of first-line chemotherapy and seems to provide a better long-term quality of life in these patients compared with second-line chemotherapy.

Effects of oral maintenance chemotherapy and predictive value of circulating EBV DNA in metastatic nasopharyngeal carcinoma

Background/Objectives

Oral maintenance chemotherapy can effectively prolong overall survival (OS) in many types of metastatic cancer, but its role in metastatic nasopharyngeal carcinoma (mNPC) is unclear. In this study, the efficacy of oral maintenance chemotherapy in mNPC and the effectiveness of circulating tumor EBV‐DNA for screening patients were evaluated.

Methods

Between June 2016 and December 2017, 141 patients with mNPC who received platinum‐based systemic chemotherapy were included (median follow‐up time, 21 months). Patients were classified into two groups according to the administration of oral maintenance chemotherapy. Plasma samples were collected before, during, and after treatment for the measurement of circulating EBV DNA.

Results

The 2‐year OS was higher for patients who received maintenance chemotherapy than for patients without maintenance chemotherapy (78.9% vs 62.7%, P = .016). Patients with undetectable posttreatment EBV‐DNA after 4‐6 cycles of systemic chemotherapy (n = 73) had a higher 2‐year OS than that of patients with detectable EBV‐DNA (n = 68) (82.16% vs 51.45%, P = .001). For patients with undetectable posttreatment EBV‐DNA, OS was better for those with maintenance chemotherapy than for those without (86.7% vs 73%, P = .027). For patients with detectable posttreatment EBV‐DNA, maintenance chemotherapy did not improve outcomes (49.5% vs 55.4%, P = .824). The most common acute events were hematological toxicity, and all were tolerable and curable.

Conclusions

Oral maintenance chemotherapy with S1 or capecitabine can improve OS in mNPC. Posttreatment EBV‐DNA was not only an independent prognosis factor for mNPC but also can screen out beneficiaries of maintenance chemotherapy.