The oligometastatic state - separating truth from wishful thinking

Dealing with the gray zones in the management of gastric cancer: The consensus statement of the İstanbul Group

The geographical location and differences in tumor biology significantly change the management of gastric cancer. The prevalence of gastric cancer ranks fifth and sixth among men and women, respectively, in Turkey. The international guidelines from the Eastern and Western countries fail to manage a considerable amount of inconclusive issues in the management of gastric cancer. The uncertainties lead to significant heterogeneities in clinical practice, lack of homogeneous data collection, and subsequently, diverse outcomes. The physicians who are professionally involved in the management of gastric cancer at two institutions in Istanbul, Turkey, organized a consensus meeting to address current problems and plan feasible, logical, measurable, and collective solutions in their clinical practice for this challenging disease. The evidence-based data and current guidelines were reviewed. The gray zones in the management of gastric cancer were determined in the first session of this consensus meeting. The second session was constructed to discuss, vote, and ratify the ultimate decisions. The identification of the T stage, the esophagogastric area, imaging algorithm for proper staging and follow-up, timing and patient selection for neoadjuvant treatment, and management of advanced and metastatic disease have been accepted as the major issues in the management of gastric cancer. The recommendations are presented with the percentage of supporting votes in the results section with related data.

Characterisation and classification of oligometastatic disease: a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation

Oligometastatic disease has been proposed as an intermediate state between localised and systemically metastasised disease. In the absence of randomised phase 3 trials, early clinical studies show improved survival when radical local therapy is added to standard systemic therapy for oligometastatic disease. However, since no biomarker for the identification of patients with true oligometastatic disease is clinically available, the diagnosis of oligometastatic disease is based solely on imaging findings. A small number of metastases on imaging could represent different clinical scenarios, which are associated with different prognoses and might require different treatment strategies. 20 international experts including 19 members of the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer OligoCare project developed a comprehensive system for characterisation and classification of oligometastatic disease. We first did a systematic review of the literature to identify inclusion and exclusion criteria of prospective interventional oligometastatic disease clinical trials. Next, we used a Delphi consensus process to select a total of 17 oligometastatic disease characterisation factors that should be assessed in all patients treated with radical local therapy for oligometastatic disease, both within and outside of clinical trials. Using a second round of the Delphi method, we established a decision tree for oligometastatic disease classification together with a nomenclature. We agreed oligometastatic disease as the overall umbrella term. A history of polymetastatic disease before diagnosis of oligometastatic disease was used as the criterion to differentiate between induced oligometastatic disease (previous history of polymetastatic disease) and genuine oligometastatic disease (no history of polymetastatic disease). We further subclassified genuine oligometastatic disease into repeat oligometastatic disease (previous history of oligometastatic disease) and de-novo oligometastatic disease (first time diagnosis of oligometastatic disease). In de-novo oligometastatic disease, we differentiated between synchronous and metachronous oligometastatic disease. We did a final subclassification into oligorecurrence, oligoprogression, and oligopersistence, considering whether oligometastatic disease is diagnosed during a treatment-free interval or during active systemic therapy and whether or not an oligometastatic lesion is progressing on current imaging. This oligometastatic disease classification and nomenclature needs to be prospectively evaluated by the OligoCare study.

Long-term survival in patients with metastatic head and neck squamous cell carcinoma treated with metastasis-directed therapy

Background

Our objective was to evaluate the outcomes of metastatic head and neck squamous cell carcinoma (HNSCC) by disease burden with an emphasis on metastasis-directed therapy (MDT) in patients with limited metastatic disease burden.

Methods

In total, 186 patients who developed metastatic disease after definitive therapy for HNSCC were included. Clinically and radiographically apparent metastases were enumerated. Kaplan–Meier methods were used to estimate survival. Cox regression was used to assess the association between clinical variables.

Results

Patients with a single metastasis had a 5-year overall survival (OS) of 35% (95% CI 16–54%) in contrast to patients with multiple metastases with a 5-year OS of 4% (95% CI 2–9%). Thirty patients (16.1%) underwent MDT. On multivariable analysis, oral cavity or sinonasal primary (HR 2.22 95% CI 1.16–4.25, p = 0.015; HR 4.88, 95% CI 1.10–21.70, p = 0.037, respectively) were associated with higher risk of death, whereas receipt of MDT (HR 0.36, 95% CI 0.17–0.74, p = 0.006) was associated with lower hazard of death. Median subsequent metastasis-free survival and 5-year survival after MDT (n = 30) were estimated at 26.4 months (95% CI: 9.8–54.0) and 31%, (95% CI: 15–48%).

Conclusions

HNSCC patients with limited metastatic disease may derive significant benefit from MDT. Prospective trials evaluating MDT in HNSCC are warranted.

The Management of Oligoprogression in the Landscape of New Therapies for Metastatic Melanoma

Background: A limited degree of progression after a response to treatment is labelled as oligoprogression and is a hot topic of metastatic melanoma (MM) management. Rogue progressive metastases could benefit from local treatment, which could allow the continuation of ongoing systemic therapy, also known as treatment beyond progression (TBP). Methods: We retrospectively reviewed 214 selected MM patients who developed oligoprogression during treatment with v-Raf murine sarcoma viral oncogene homolog B (BRAF)/mitogen-activated-extracellular signal-regulated kinase (MEK) or programmed cell death protein 1 (PD-1) inhibitors and received a local treatment continuing TBP. We performed univariate and multivariable analyses to assess the association between therapy outcomes and a series of clinical and biological features. Results: We identified 27 (10%) oligoprogressed patients treated locally with surgery (14), radiosurgery (11), and electrochemotherapy (2). TBP included PD-1 inhibitors (13) and BRAF/MEK inhibitors (14). The median progression-free survival post oligoprogression (PFSPO) was 14 months (5-19 95% confidence interval (C.I.)). In the univariate analysis, a significantly longer PFSPO was associated with complete response (CR), Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, neutrophils/lymphocytes ratio (N/L) <2, and progression-free survival (PFS) at oligoprogression >11 months. Nevertheless, in the multivariable analysis, only CR and N/L <2 were found to be associated with longer PFSPO. Conclusions: In selected patients, local treatments contribute to controlling oligoprogression for a long time, allowing the continuation of systemic treatment and prolongation of overall survival (OS). Increasing biological and clinical knowledge is improving the accuracy in identifying patients to apply for local ablative therapies.

Local ablative radiotherapy for oligometastatic non-small cell lung cancer

In metastatic non-small cell lung cancer (NSCLC), the role of radiotherapy (RT) has been limited to palliation to alleviate the symptoms. However, with the development of advanced RT techniques, recent advances in immuno-oncology therapy targeting programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) and targeted agents for epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) translocation allowed new roles of RT in these patients. Within this metastatic population, there is a subset of patients with a limited number of sites of metastatic disease, termed as oligometastasis that can achieve long-term survival from aggressive local management. There is no consensus on the definition of oligometastasis; however, most clinical trials define oligometastasis as having 3 to 5 metastatic lesions. Recent phase II randomized clinical trials have shown that ablative RT, including stereotactic ablative body radiotherapy (SABR) and hypofractionated RT, to primary and metastatic sites improved progression-free survival (PFS) and overall survival (OS) in patients with oligometastatic NSCLC. The PEMBRO-RT study, a randomized phase II study comparing SABR prior to pembrolizumab therapy and pembrolizumab therapy alone, revealed that the addition of SABR improved the overall response, PFS, and OS in patients with advanced NSCLC. The efficacy of RT in oligometastatic lung cancer has only been studied in phase II studies; therefore, large-scale phase III studies are needed to confirm the benefit of local ablative RT in patients with oligometastatic NSCLC. Local intensified RT to primary and metastatic lesions is expected to become an important treatment paradigm in the near future in patients with metastatic lung cancer.

Progression-directed Therapy for Oligoprogression in Castration-refractory Prostate Cancer

In metastatic castration-refractory prostate cancer (mCRPC), state-of-the-art treatment consists of androgen biosynthesis inhibition (abiraterone), inhibition of the androgen receptor (enzalutamide), chemotherapy, or radium-223 in combination with androgen deprivation therapy (ADT). A subgroup of these patients show oligoprogression, with the progression of only a limited number of metastatic spots, while all other metastases remain controlled by ongoing systemic therapy. In a bi-institutional retrospective study, we tested the hypothesis that progression-directed therapy (PDT) targeting oligoprogressive lesions might defer the initiation of next-line systemic treatment (NEST). A total of 30 patients were diagnosed with mCRPC and experienced oligoprogression, defined as a total of three or fewer progressive lesions either at known metastatic sites and/or the appearance of new metastasis and/or local recurrence. All patients were under active ADT with or without second-line systemic treatment. All patients received PDT targeting the oligoprogressive lesions, while ongoing systemic treatment was maintained. There was median NEST-free survival of 16mo (95% confidence interval [CI] 10-22) and progression-free survival of 10mo (95% CI 6-15) with only minor radiotherapy- or surgery-related toxicity. These findings encourage further prospective trials. PATIENT SUMMARY: In patients with metastatic castration-refractory prostate cancer, surgical treatment or high-dose radiation therapy directed to only the limited number of progressive metastatic spots, while all other metastases remained controlled by ongoing systemic therapy, led to substantial postponement of next-line systemic treatment in our study.

Radiological complete remission in HER2-positive metastatic breast cancer patients: what to do with trastuzumab?

PURPOSE

Patients with HER2-positive metastatic breast cancer (MBC) treated with trastuzumab may experience durable tumor response for many years. It is unknown if patients with durable radiological complete remission (rCR) can discontinue trastuzumab. We analyzed clinical characteristics associated with rCR and overall survival (OS) in a historic cohort of patients with HER2-positive MBC and studied the effect of stopping trastuzumab in case of rCR.

METHODS

We included patients with HER2-positive MBC treated with first or second-line trastuzumab-based therapy in eight Dutch hospitals between 2000 and 2014. Data were collected from medical records. We used multivariable regression models to identify independent prognostic factors for rCR and OS. Time-to-progression after achieving rCR for patients who continued and stopped trastuzumab, and breast cancer-specific survival were also evaluated.

RESULTS

We identified 717 patients with a median age of 53 years at MBC diagnosis. The median follow-up was 109 months (IQR 72-148). The strongest factor associated with OS was achievement of rCR, adjusted hazard ratio 0.27 (95% CI 0.18-0.40). RCR was observed in 72 patients (10%). The ten-year OS estimate for patients who achieved rCR was 52 versus 7% for patients who did not achieve rCR. Thirty patients with rCR discontinued trastuzumab, of whom 20 (67%) are alive in ongoing remission after 78 months of median follow-up since rCR. Of forty patients (58%) who continued trastuzumab since rCR, 13 (33%) are in ongoing remission after 68 months of median follow-up. Median time-to-progression in the latter group was 14 months.

CONCLUSIONS

Achieving rCR is the strongest predictor for improved survival in patients with HER2-positive MBC. Trastuzumab may be discontinued in selected patients with ongoing rCR. Further research is required to identify patients who have achieved rCR and in whom trastuzumab may safely be discontinued.

Selection of systemic therapy in patients with locally advanced and recurrent/metastatic head and neck cancer: RAND-based expert opinion by an Italian multidisciplinary panel

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease often presenting at an already advanced stage. Cisplatin chemoradiotherapy is the standard treatment for locally advanced disease, although its efficacy varies according to different studies. Thus, treatment selection is a challenge, especially in older patients, who frequently have several comorbidities. Moreover, the majority of patients with recurrent and/or metastatic disease are unsuitable for local treatment, either surgery or radiation therapy. The only treatment option for them is systemic therapy, but prognosis remains poor, with a median overall survival of less than 12 months.

METHODS

A group of Italian key opinion leaders in the field of HNSCC gathered several times in 2018 in order to retrieve a set of statements to help clinicians in their daily decision-making process for the treatment of patients with different scenarios of HNSCC.

RESULTS AND CONCLUSION

The panel agreed on 22 statements that were identified as "good clinical points" based on the available literature or after discussion of the most relevant aspect of the underlying diseases when no international consensus was available. The panel identified a number of possible scenarios (namely 71) in which these statements may be helpful to guide decision-making for the best treatment selection.

Evolution of treatment strategies for oligometastatic NSCLC patients - A systematic review of the literature

BACKGROUND

The concept of oligometastatic disease (OMD) has expanded the scope of potentially curative therapy for metastatic NSCLC. However, large uncertainties remain regarding its definition and optimal management strategies. We therefore conducted a systematic review to investigate the value of various multimodality treatment concepts.

METHODS

We searched the available literature in Pubmed, Medline and EMBASE using the terms "oligomet*", "synchron*", "oligorec*", "metachr*" "NSCLC", "lung cancer" and "stage IV" and included studies reporting treatment regimens and outcomes on radically treated patients with either "synchronous", "metachronous" or "mixed" OMD. Only de-novo diagnosis of OMD was considered. The impact of patient and treatment characteristics on overall survival (OS) and time trends in patterns of care were investigated.

RESULTS

54 studies published between 1987 and 2018 were included. Despite a wide range of OMD definitions, 90.1% of patients were treated for a single metastasis. Systemic therapy was used as backbone treatment for most patients. Although surgery was the preferred local treatment in earlier studies, the use of stereotactic radiotherapy increased rapidly after 2011. No OS difference was observed between surgery or radiotherapy as the treatment of primary tumor or metastases, respectively. A time trend towards improved OS after 2011 could be detected.

CONCLUSIONS

While evidence in favor of radical treatment is emerging, most studies remain retrospective and mainly evaluate patients with singular metastases. While surgery, stereotactic radiotherapy and chemotherapy are the cornerstones of current treatment strategies, future clinical trials need to address the high risk of distant metastases by integrating targeted or immunotherapy.

[Oligometastases and oligoprogressions: Concepts and natural history]

The oligometastatic paradigm refers to an intermediate biologic state of cancer with restricted metastatic capacity. Its phenotype is characterized by a limited number of metastases and a slow tumor growth. Various clinical and pre-clinical studies associated this state to alterations of the biological mechanisms involved in metastatic diffusion. Eventually, this transitional state leads to a wide metastatic dissemination. However, there is a period during which the patient could benefit from local ablative treatment. Depending on several prognostic factors and the treatment provided, long survival or even healing can sometimes be achieved. The selection of patients eligible for such a curative strategy may be adapted following clinical, radiological or biological markers. Recent improvement of therapeutic and imaging are changing the clinical definition of oligometastatic cancer, which should be adapted to evidence from recent clinical and preclinical data.

Tumor biology and multidisciplinary strategies of oligometastasis in gastrointestinal cancers

More than 70% of gastrointestinal (GI) cancers are diagnosed with metastases, leading to poor prognosis. For some cancer patients with limited sites of metastatic tumors, the term oligometastatic disease (OMD) has been coined as opposed to systemic polymetastasis (PMD) disease. Stephan Paget first described an organ-specific pattern of metastasis in 1889, now known as the "seed and soil" theory where distinct cancer types are found to metastasize to different tumor-specific sites. Our understanding of the biology of tumor metastasis and specifically the molecular mechanisms driving their formation are still limited, in particular, as it relates to the genesis of oligometastasis. In the following review, we discuss recent advances in general understanding of this metastatic behavior including the role of specific signaling pathways, various molecular features and biomarkers, as well as the interaction of carcinoma cells with their tissue microenvironments (both primary and metastatic niches). The unique features that underlie OMD provide potential targets for localized therapy. As it relates to clinical practice, OMD is emerging as treatable with surgical resection and/or other local therapy options. Strategies currently being applied in the clinical management of OMD will be discussed including surgical, radiation-based therapy, ablation procedures, and the results of emerging clinical trials involving immunotherapy.

Stereotactic ablative radiotherapy for the comprehensive treatment of 4-10 oligometastatic tumors (SABR-COMET-10): study protocol for a randomized phase III trial

Background

Stereotactic ablative radiotherapy (SABR) has emerged as a new treatment option for patients with oligometastatic disease. SABR delivers precise, high-dose, hypofractionated radiotherapy, and achieves excellent rates of local control for primary tumors or metastases. A recent randomized phase II trial evaluated 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 benefits in progression-free survival and overall survival. The goal of this phase III trial is to assess the impact of SABR in patients with 4–10 metastatic cancer lesions.

Methods

One hundred and fifty-nine patients will be randomized in a 1:2 ratio between the control arm (consisting of standard of care palliative-intent treatments), and the SABR arm (consisting of standard of care treatment + SABR to all sites of known disease). Randomization will be stratified by two factors: histology (Group 1: prostate, breast, or renal; Group 2: all others), and type of pre-specified systemic therapy (Group 1: immunotherapy/targeted; Group 2: cytotoxic; Group 3: observation). SABR is to be completed within 2 weeks, allowing for rapid initiation of systemic therapy. Recommended SABR doses are 20 Gy in 1 fraction, 30 Gy in 3 fractions, or 35 Gy in 5 fractions, chosen to minimize risks of toxicity. The primary endpoint is overall survival, and secondary endpoints include progression-free survival, time to development of new metastatic lesions, quality of life, 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 clinical outcomes and quality of life, to determine if long-term survival can be achieved for selected patients with 4–10 oligometastatic lesions.

Trial registration

Clinicaltrials.gov identifier: NCT03721341. Date of registration: October 26, 2018.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5977-6) contains supplementary material, which is available to authorized users.

Limiting tumor seeding as a therapeutic approach for metastatic disease

Here we propose that therapeutic targeting of circulating tumor cells (CTCs), which are widely understood to be the seeds of metastasis, would represent an effective strategy towards limiting numerical expansion of secondary lesions and containing overall tumor burden in cancer patients. However, the molecular mediators of tumor seeding have not been well characterized. This is in part due to the limited number of pre-clinical in vivo approaches that appropriately interrogate the mechanisms by which cancer cells home to arresting organs. It is critical that we continue to investigate the mediators of tumor seeding as it is evident that the ability of CTCs to colonize in distant sites is what drives disease progression even after the primary tumor has been ablated by local modalities. In addition to slowing disease progression, containing metastatic spread by impeding tumor cell seeding may also provide a clinical benefit by increasing the duration of the residence of CTCs in systemic circulation thereby increasing their exposure to pharmacological agents commonly used in the treatment of patients such as chemotherapy and immunotherapies. In this review we will examine the current state of knowledge about the mechanisms of tumor cells seeding as well as explore how targeting this stage of metastatic spreading may provide therapeutic benefit to patients with advanced disease.

Imaging Diagnosis and Follow-up of Advanced Prostate Cancer: Clinical Perspectives and State of the Art

The management of advanced prostate cancer has changed substantially with the availability of multiple effective novel treatments, which has led to improved disease survival. In the era of personalized cancer treatments, more precise imaging may help physicians deliver better care. More accurate local staging and earlier detection of metastatic disease, accurate identification of oligometastatic disease, and optimal assessment of treatment response are areas where modern imaging is rapidly evolving and expanding. Next-generation imaging modalities, including whole-body MRI and molecular imaging with combined PET and CT and combined PET and MRI using novel radiopharmaceuticals, create new opportunities for imaging to support and refine management pathways in patients with advanced prostate cancer. This article demonstrates the potential and challenges of applying next-generation imaging to deliver the clinical promise of treatment breakthroughs.

Stereotactic ablative radiotherapy versus standard of care palliative treatment in patients with oligometastatic cancers (SABR-COMET): a randomised, phase 2, open-label trial

BACKGROUND

The oligometastatic paradigm suggests that some patients with a limited number of metastases might be cured if all lesions are eradicated. Evidence from randomised controlled trials to support this paradigm is scarce. We aimed to assess the effect of stereotactic ablative radiotherapy (SABR) on survival, oncological outcomes, toxicity, and quality of life in patients with a controlled primary tumour and one to five oligometastatic lesions.

METHODS

This randomised, open-label phase 2 study was done at 10 hospitals in Canada, the Netherlands, Scotland, and Australia. Patients aged 18 or older with a controlled primary tumour and one to five metastatic lesions, Eastern Cooperative Oncology Group score of 0-1, and a life expectancy of at least 6 months were eligible. After stratifying by the number of metastases (1-3 vs 4-5), we randomly assigned patients (1:2) to receive either palliative standard of care treatments alone (control group), or standard of care plus SABR to all metastatic lesions (SABR group), using a computer-generated randomisation list with permuted blocks of nine. Neither patients nor physicians were masked to treatment allocation. The primary endpoint was overall survival. We used a randomised phase 2 screening design with a two-sided α of 0·20 (wherein p<0·20 designates a positive trial). All analyses were intention to treat. This study is registered with ClinicalTrials.gov, number NCT01446744.

FINDINGS

99 patients were randomised between Feb 10, 2012, and Aug 30, 2016. Of 99 patients, 33 (33%) were assigned to the control group and 66 (67%) to the SABR group. Two (3%) patients in the SABR group did not receive allocated treatment and withdrew from the trial; two (6%) patients in the control group also withdrew from the trial. Median follow-up was 25 months (IQR 19-54) in the control group versus 26 months (23-37) in the SABR group. Median overall survival was 28 months (95% CI 19-33) in the control group versus 41 months (26-not reached) in the SABR group (hazard ratio 0·57, 95% CI 0·30-1·10; p=0·090). Adverse events of grade 2 or worse occurred in three (9%) of 33 controls and 19 (29%) of 66 patients in the SABR group (p=0·026), an absolute increase of 20% (95% CI 5-34). Treatment-related deaths occurred in three (4·5%) of 66 patients after SABR, compared with none in the control group.

INTERPRETATION

SABR was associated with an improvement in overall survival, meeting the primary endpoint of this trial, but three (4·5%) of 66 patients in the SABR group had treatment-related death. Phase 3 trials are needed to conclusively show an overall survival benefit, and to determine the maximum number of metastatic lesions wherein SABR provides a benefit.

FUNDING

Ontario Institute for Cancer Research and London Regional Cancer Program Catalyst Grant.

Personalized Radiation Therapy in Cancer Pain Management

The majority of advanced cancer patients suffer from pain, which severely deteriorates their quality of life. Apart from analgesics, bisphosphonates, and invasive methods of analgesic treatment (e.g., intraspinal and epidural analgesics or neurolytic blockades), radiation therapy plays an important role in pain alleviation. It is delivered to a growing primary tumour, lymph nodes, or distant metastatic sites, producing pain of various intensity. Currently, different regiments of radiation therapy methods and techniques and various radiation dose fractionations are incorporated into the clinical practice. These include palliative radiation therapy, conventional external beam radiation therapy, as well as modern techniques of intensity modulated radiation therapy, volumetrically modulated arch therapy, stereotactic radiosurgery or stereotactic body radiation therapy, and brachytherapy or radionuclide treatment (e.g., radium-223, strontium-89 for multiple painful osseous metastases). The review describes the possibilities and effectiveness of individual patient-tailored conventional and innovative radiation therapy approaches aiming at pain relief in cancer patients.

Multidisciplinary Tumor Board Recommendations for Oligometastatic Malignancies: A Prospective Single-Center Analysis

BACKGROUND

The treatment of oligometastatic disease is challenging and few data exist to guide treatment decisions. The objective of this study was to improve the data on the prevalence and treatment of patients with oligometastatic disease.

METHODS

We conducted a prospective single-center analysis that included all consecutive patients discussed in multidisciplinary tumor boards (MDT) between February and July 2017. Patients with oligometastatic disease were identified and treatment strategies were evaluated.

RESULTS

1,673 patients were included in this study, 609 (36.4%) presented with metastatic disease, 151 (9%) had oligometastatic disease. Common metastatic sites were brain, liver, and lung. Lung cancer patients were the largest cohort (20.5%) among all patients with oligometastatic disease compared with other tumor entities. The majority of oligometastatic patients (68.9%) received local treatment with or without additional chemotherapy, 17.9% were recommended systemic therapy alone. MDT recommended watchful waiting for 4.6% of the patients.

CONCLUSION

Patients with oligometastatic disease represent a considerable proportion of all patients in MDT. In this study, 68.9% of patients with oligometastatic disease received regional treatment. This shows a possible treatment shift from palliative to potentially curative intent. These data may be used to design prospective clinical trials to optimize the treatment of oligometastatic disease.

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Canadian consensus: oligoprogressive, pseudoprogressive, and oligometastatic non-small-cell lung cancer

Background

Little evidence has been generated for how best to manage patients with non-small-cell lung cancer (nsclc) presenting with rarer clinical scenarios, including oligometastases, oligoprogression, and pseudoprogression. In each of those scenarios, oncologists have to consider how best to balance efficacy with quality of life, while maximizing the duration of each line of therapy and ensuring that patients are still eligible for later options, including clinical trial enrolment.

Methods

An expert panel was convened to define the clinical questions. Using case-based presentations, consensus practice recommendations for each clinical scenario were generated through focused, evidence-based discussions.

Results

Treatment strategies and best-practice or consensus recommendations are presented, with areas of consensus and areas of uncertainty identified.

Conclusions

In each situation, treatment has to be tailored to suit the individual patient, but with the intent of extending and maximizing the use of each line of treatment, while keeping treatment options in reserve for later lines of therapy. Patient participation in clinical trials examining these issues should be encouraged.

Stereotactic Radiotherapy for Oligometastasis

Oligometastatic disease is defined as “a condition with a few metastases arising from tumors that have not acquired a potential for widespread metastases.” Its behavior suggests a transitional malignant state somewhere between localized and metastatic cancer. Treatment of oligometastatic disease is expected to achieve long-term local control and to improve survival. Historically, patients with oligometastases have often undergone surgical resection since it was anecdotally believed that surgical resection could result in progression-free or overall survival benefits. To date, no prospective randomized trials have demonstrated surgery-related survival benefits. Short courses of highly focused, extremely high-dose radiotherapies (e.g., stereotactic radiosurgery and stereotactic ablative body radiotherapy (SABR)) have frequently been used as alternatives to surgery for treatment of oligometastasis. A randomized study has demonstrated the overall survival benefits of stereotactic radiosurgery for solitary brain metastasis. Following the success of stereotactic radiosurgery, SABR has been widely accepted for treating extracranial metastases, considering its efficacy and minimum invasiveness. In this review, we discuss the history of and rationale for the local treatment of oligometastases and probe into the implementation of SABR for oligometastatic disease.

Oligometastatic prostate cancer: Reality or figment of imagination?

The term “oligometastatic prostate cancer” refers to a heterogeneous group of disease states currently defined solely on the basis of clinical features. Oligorecurrent disease, de novo oligometastases, and oligoprogressive disease likely have unique biologic underpinnings and natural histories. Evidence suggesting the existence of a subset of patients who harbor prostate cancer with limited metastatic potential currently includes disparate and overwhelmingly retrospective reports. Nevertheless, emerging prospective data have corroborated the “better‐than‐expected,” retrospectively observed outcomes, particularly in the setting of oligorecurrent prostate cancer. Improved functional imaging with prostate‐specific membrane antigen‐targeted strategies may enhance the identification of patients with oligometastatic prostate cancer in the short term. In the long term, refinement of the oligometastatic case definition likely will require biologic risk‐stratification schemes. To determine optimal treatment strategies and identify patients most likely to benefit from metastasis‐directed therapy, future efforts should focus on conducting high‐quality, prospective trials with much‐needed molecular correlative studies.

The term “oligometastatic prostate cancer” currently refers to a heterogeneous group of clinically defined disease states. To improve patient risk stratification and determine optimal treatment strategies, future efforts should focus on conducting prospective trials and determining a biologic categorization of patients with limited metastatic potential.

The role of definitive chemoradiation in patients with non-metastatic oesophageal cancer

Definitive chemoradiation (dCRT) is a curative treatment option for patients with oesophageal cancer. It is effective in both adenocarcinoma and squamous cell carcinoma. However, locoregional control is less after dCRT compared to preoperative CRT (pCRT) followed by surgery. Also, overall survival is lower compared to pCRT followed by surgery, which can only partly be explained by a negative selection of patients. The optimal dose of radiotherapy remains to be determined, but dose escalation above 50.4Gy might be beneficial. Cisplatinum/5-FU is the most applied concurrent chemotherapy, but carboplatin/paclitaxel seems equally effective with less toxicity. The addition of 5-FU to a taxane and platinum seems promising. Accelerated fractionation and addition of cetuximab did not improve results. dCRT is a successful treatment for regional lymph node recurrences, but less so for recurrences at the anastomotic site. Re-irradiation after prior curative radiotherapy yields poor results. dCRT can be safely used in carefully selected elderly.

The 46th David A. Karnofsky Memorial Award Lecture: Oligometastasis—From Conception to Treatment

Metastasis from most adult solid tumors generally has been considered to be widespread and incurable. Here, I present clinical and molecular data to support the hypothesis that some metastases are limited in number and pace and are curable with ablative therapies. I advance the hypothesis that immunotherapy combined with radiotherapy may be a general strategy to increase the number of patients with metastatic cancer amenable to cure. I further suggest that, in the context of ablative radiotherapy, the potential synergies between immunotherapy and radiotherapy are principally within the local tumor microenvironment and require treatment of all or most sites of metastatic disease. Improvements in the molecular staging of metastasis, immunotherapy strategies, and radiotherapy delivery are likely to improve outcomes for patients with metastatic cancer.

Oligometastatic breast cancer

Metastatic breast cancer (MBC) is considered as incurable. The group of patients with oligometastatic disease (a few metastatic lesions and organs involved) apparently have better prognosis. It is claimed that, these patients could be treated with curative intent, and multidisciplinary aggressive approach should be considered. Despite the lack of strong data it is increasingly accepted in clinical practice. Currently, the appropriate candidate would be young woman with good performance status, low tumour burden with long disease-free interval. Because for them with already favorable nature of their disease, aggressive treatment has greater chances to improve survivals. Local ablative treatment (radiotherapy/surgery) has a crucial role in this setting. Available mainly from retrospective in nature long-term results are encouraging but need confirmation in prospective randomized studies. In this review, I discuss the definition of oligometastatic disease, its nature, currently available data and ongoing prospective randomized trials dedicated to oligometastatic breast cancer patients.

Novel Insights into the Management of Oligometastatic Prostate Cancer: A Comprehensive Review

CONTEXT

The current standard of care for metastatic prostate cancer (PCa) is androgen deprivation therapy (ADT) plus either docetaxel or abiraterone. Growing evidence suggests that metastasis-directed therapy (MDT) and/or local therapy targeted to the primary tumour (ie, prostate) may be of benefit in the setting of oligometastatic disease. Several prospective studies are underway; however, until robust evidence is available to guide treatment decisions, physicians are challenged with how best to manage patients with oligometastases.

OBJECTIVE

This comprehensive review aims to collate the available evidence to date for a role of MDT and/or prostate-targeted therapy in the setting of oligometastatic PCa, as well as discuss ongoing trials in this setting.

EVIDENCE ACQUISITION

We searched PubMed for the combination of "prostate cancer" and "oligometastatic", "oligometastases", "oligometastasis", "solitary metastases", "stereotactic body radiotherapy", "SBRT", "stereotactic ablative radiotherapy", "SABR", "salvage lymphadenectomy", or "metastasectomy" in publications over the last 20yr. We also searched ClinicalTrials.gov to identify relevant ongoing trials.

EVIDENCE SYNTHESIS

The studies were divided according to the timing of metastasis into synchronous (ie, detected at the time of primary PCa diagnosis) and metachronous (ie, detected after treatment of the primary tumour), and according to treatment modality into MDT (including salvage lymph node dissection [sLND]) and prostate-targeted treatment. For MDT of synchronous/metachronous metastases, we included 16 completed studies and 11 ongoing prospective studies. In the case of sLND for nodal-only recurrence after primary treatment with curative intent, we included 11 completed studies. Finally, for prostate-targeted treatment of synchronous metastatic PCa, we included 25 completed studies and 11 ongoing prospective studies. In selected patients with oligorecurrent disease, early detection and aggressive treatment of metastatic lesions (surgery or radiotherapy) appears to be a feasible strategy and may delay the use of systemic therapies. MDT is a promising option in oligometastatic PCa patients, but more robust data are needed. In the setting of synchronous oligometastatic disease, aggressive cytoreductive treatment needs further data to confirm the benefits.

CONCLUSIONS

In this review, we provide a comprehensive overview of the current literature on the treatment of patients with oligometastatic PCa. The data suggest that although ADT plus either docetaxel or abiraterone remains the mainstay of treatment for mPCa, in oligometastatic PCa, improved outcomes may be achieved with metastasis- and prostate-targeted therapies. The studies included in this review are mainly retrospective in nature, limiting the strength of the evidence they provide. Prospective studies are ongoing, and their results are eagerly awaited.

PATIENT SUMMARY

We reviewed the treatment of patients with prostate cancer that has spread to five sites or fewer. We conclude that while androgen deprivation plus either docetaxel or abiraterone should remain the standard of care, there is evidence that treatment targeted at the metastases and the primary tumour may improve the outcome for the patient and potentially delay the use of systemic treatment.

Population-based phase II trial of stereotactic ablative radiotherapy (SABR) for up to 5 oligometastases: SABR-5

BACKGROUND

Oligometastases refer to a state of disease where cancer has spread beyond the primary site, but is not yet widely metastatic, often defined as 1-3 or 1-5 metastases in number. Stereotactic ablative radiotherapy (SABR) is an emerging radiotherapy technique to treat oligometastases that require further prospective population-based toxicity estimates.

METHODS

This is a non-randomized phase II trial where all participants will receive experimental SABR treatment to all sites of newly diagnosed or progressing oligometastatic disease. We will accrue 200 patients to assess toxicity associated with this experimental treatment. The study was powered to give a 95% confidence on the risk of late grade 4 toxicity, anticipating a < 5% rate of grade 4 toxicity.

DISCUSSION

SABR treatment of oligometastases is occurring off-trial at a high rate, without sufficient evidence of its efficacy or toxicity. This trial will provide necessary toxicity data in a population-based cohort, using standardized doses and organ at risk constraints, while we await data on efficacy from randomized phase III trials.

TRIAL REGISTRATION

Registered through clinicaltrials.gov NCT02933242 on October 14, 2016 prospectively before patient accrual.

Local ablative treatment for synchronous single organ oligometastatic lung cancer-A propensity score analysis of 180 patients

INTRODUCTION

Local ablative treatment (LAT) improves outcome in lung cancer with oligometastatic disease (OMD) and potentially leads to long term survival. The aim of this retrospective study was to evaluate and quantify the additional benefit of LAT in synchronous OMD and to further identify prognostic factors for survival.

PATIENTS AND METHODS

A propensity score-matched pairs analysis was performed on a set of patient and disease variables in 180 patients, treated for synchronous single organ OMD including non small-cell and neuroendocrine lung cancer with ≤4 metastases between 2000 and 2016 in 3 lung cancer centers in Berlin, Germany. Patients either received LAT for all sites of disease (intervention group) by means of surgery or stereotactic radiotherapy, or standard chemotherapy, if necessary combined with a local treatment with palliative intent (control group).

RESULTS

Median follow-up time was 32.2 and 18.8 months for the intervention and control group, respectively. Substantial benefits in median progression-free survival (PFS, 25.1 vs. 8.2 months; HR, 0.30; 95% CI, 0.21-0.43; p < 0.001) and overall survival (OS, 60.4 vs. 22.5 months; HR, 0.42; 95% CI, 0.28-0.62; p < 0.001) were associated with LAT. Histology of adenocarcinoma and T1a primaries also predicted a favorable prognosis concerning PFS and OS. More favorable nodal stage (N0-2 vs. 3) and solitary metastases were associated with an extended PFS, whereas initial ECOG-PS (0-1 vs. 2) predicted OS.

CONCLUSIONS

LAT was the strongest predictor for PFS and OS in OMD with ≤4 metastases. Survival in the control group identifies OMD as a subset of lung cancer with a generally more favorable prognosis.

Efficacy of Local Consolidative Therapy for Oligometastatic Lung Adenocarcinoma Patients Harboring Epidermal Growth Factor Receptor Mutations

BACKGROUND

For oligometastatic lung adenocarcinoma patients with sensitive epidermal growth factor receptor (EGFR) mutations, the role of local consolidative therapy (LCT) remains debatable. The purpose of this study was to investigate the efficacy of LCT in oligometastatic lung adenocarcinoma patients.

PATIENTS AND METHODS

We conducted a retrospective study to assess the effects of LCT on progression-free survival (PFS) and overall survival (OS). Patients with advanced-stage oligometastatic lung adenocarcinoma harboring sensitive mutation of epidermal growth factor receptor (EGFR) who received EGFR-tyrosine kinase inhibitor (TKI) or EGFR-TKI plus LCT were admitted to Shanghai Chest Hospital from January 2010 to December 2016. The PFS and OS of the 2 groups were accordingly analyzed.

RESULTS

A total of 231 patients (143 patients who received LCT plus EGFR-TKI [combination group] and 88 patients who only received EGFR-TKI only [monotherapy group]) were included in this study. Median PFS was significantly longer in the combination group (15 months; 95% confidence interval [CI], 13.611-16.389) than in the monotherapy group (10 months; 95% CI, 8.936-11.064; hazard ratio = 0.610; 95% CI, 0.461, 0.807; P = .000). The median OS in the combination group was 34 months (95% CI, 27.889, 40.111) versus 21 months (95% CI, 18.445, 23.555) in the monotherapy group (hazard ratio = 0.593; 95% CI, 0.430-0.817; P = .001).

CONCLUSION

LCT combined with TKIs therapy was a feasible method that significantly improved PFS and OS among oligometastatic lung adenocarcinoma patients with EGFR mutations, and it thus might be considered as an important medical treatment during clinical management.

Stereotactic body radiotherapy for centrally-located lung tumors with 56 Gy in seven fractions: A retrospective study

Stereotactic body radiotherapy (SBRT) for centrally-located lung tumors remains a challenge because of the increased risk of treatment-related adverse events (AEs), and uncertainty around prescribing the optimal dose. The present study reported the results of central tumor SBRT with 56 Gy in 7 fractions (fr) at the University of Tokyo Hospital. A total of 35 cases that underwent SBRT with or without volumetric-modulated arc therapy consisting of 56 Gy/7 fr for central lung lesions between 2010 and 2016 at the University of Tokyo Hospital were reveiwed. A central lesion was defined as a tumor within 2 cm of the proximal bronchial tree (RTOG 0236 definition) or within 2 cm in all directions of any critical mediastinal structure. Local control (LC), overall survival (OS), and AEs were investigated. The Kaplan-Meier method was used to estimate LC and OS. AEs were scored per the Common Terminology Criteria for Adverse Events Version 4.0. Thirty-five patients with 36 central lung lesions were included. Fifteen lesions were primary non-small cell lung cancer (NSCLC), 13 were recurrences of NSCLC, and 8 had oligo-recurrences from other primaries. Median tumor diameter was 29 mm. Eighteen patients had had prior surgery. At a median follow-up of 13.1 months for all patients and 18.3 months in surviving patients, 22 patients had died, ten due to primary disease (4 NSCLC), while three were treatment-related. The 1- and 2-year OS were 57.3 and 40.4%, respectively, and median OS was 15.7 months. Local recurrence occurred in only two lesions. 1- and 2-year LC rates were both 96%. Nine patients experienced grade ≥3 toxicity, representing 26% of the cohort. Two of these were grade 5, one pneumonitis and one hemoptysis. Considering the background of the subject, tumor control of our central SBRT is promising, especially in primary NSCLC. However, the safety of SBRT to central lung cancer remains controversial.

Stereotactic ablative radiation therapy for oligometastatic prostate cancer delays time-to-next systemic treatment

PURPOSE

Local ablative treatment to oligometastatic patients can result in long-term disease-free survival in some cancer patients. The importance of this treatment paradigm in prostate cancer is a rapidly evolving field. Herein, we report on the safety and preliminary clinical outcomes of a modern cohort of oligometastatic prostate cancer (OPC) patients treated with consolidative stereotactic ablative radiation (SABR).

METHODS

Records of men with OPC who underwent consolidative SABR at our institution were reviewed. SABR was delivered in 1-5 fractions of 5-18 Gray. Kaplan-Meier estimates of local progression-free survival (LPFS), biochemical progression-free survival (bPFS; PSA nadir + 2), distant progression-free survival (DPFS), and time-to-next intervention (TTNI) were calculated.

RESULTS

In total, 66 OPC patients were identified with consolidative SABR delivered to 134 metastases: 89 bone, 40 nodal, and 5 viscera. The majority of men (49/66) had hormone-sensitive prostate cancer (HSPC). Crude grade 1 and 2 acute toxicities were 36% and 11%, respectively, with no ≥ grade 3 toxicity. At 1 year, LPFS was 92% and bPFS and DPFS were 69%. Of the 18 men with HSPC who had deferred hormone therapy , 11 (56%) remain disease free following SABR (1-year ADT-FS was 78%). In 17 castration-resistant men, 11 had > 50% prostate-specific antigen (PSA) declines with 1-year TTNI of 30%.

CONCLUSIONS

Consolidative SABR in OPC is feasible and well tolerated. The heterogeneity and small size of our series limit extrapolation of clinically meaningful outcomes following consolidative SABR in OPC, but our preliminary data suggest that this approach warrants continued prospective study.

Indian consensus statement for treatment of advanced non small cell lung cancer: First line, maintenance, and second line

The management of advanced nonsmall cell lung cancer (NSCLC) patients is becoming complex with the identification of driver mutations and targeted therapies. The expert group of academic medical oncologists used data from published literature, practical experience to arrive at practical consensus recommendations to treat advanced NSCLC for use by the community oncologists.

Integrated molecular subtyping defines a curable oligometastatic state in colorectal liver metastasis

The oligometastasis hypothesis suggests a spectrum of metastatic virulence where some metastases are limited in extent and curable with focal therapies. A subset of patients with metastatic colorectal cancer achieves prolonged survival after resection of liver metastases consistent with oligometastasis. Here we define three robust subtypes of de novo colorectal liver metastasis through integrative molecular analysis. Patients with metastases exhibiting MSI-independent immune activation experience the most favorable survival. Subtypes with adverse outcomes demonstrate VEGFA amplification in concert with (i) stromal, mesenchymal, and angiogenic signatures, or (ii) exclusive NOTCH1 and PIK3C2B mutations with E2F/MYC activation. Molecular subtypes complement clinical risk stratification to distinguish low-risk, intermediate-risk, and high-risk patients with 10-year overall survivals of 94%, 45%, and 19%, respectively. Our findings provide a framework for integrated classification and treatment of metastasis and support the biological basis of curable oligometastatic colorectal cancer. These concepts may be applicable to many patients with metastatic cancer.

Local Therapy Indications in the Management of Patients with Oligometastatic Non-Small Cell Lung Cancer

Advances in surgical, radiation, and interventional radiology therapies carry a reduction in morbidity associated with therapy. Aggressive management of patients with oligometastatic non-small cell lung cancer offers the potential for improved disease-free survival and quality of life compared with traditional systemic therapy alone.

The role of radiation therapy in bone metastases management

Bone metastases represent an important complication of malignant tumours. Despite improvement in surgical techniques and advances in systemic therapies, management of patients with bone metastatic disease remains a powerful cornerstone for the radiation oncologist. The primary goal of radiation therapy is to provide pain relief, preserving patients quality of life.

Prevention of serious skeletal-related events by interventional radiology techniques in patients with malignant paraganglioma and pheochromocytoma

PURPOSE

Bone metastases (BM) and skeletal-related events (SRE) are frequent in patients with malignant pheochromocytoma and paraganglioma (PPM) and the best modality of prevention unknown. The role of interventional radiology (IR) techniques for the prevention of SRE in the multidisciplinary management of malignant PPM has not been evaluated in that setting.

METHODS

Single referral center retrospective review of all patients with malignant PPM with BM from 2000 to 2016. The primary endpoint was the time to first serious SRE (TTSRE). At time of inclusion, patients with high bone tumor burden disease were defined as those having more than five BM with the biggest exceeding 2 cm (Group A) and patients with moderate bone tumor burden disease were defined as those having five or less BM or no BM exceeding 2 cm (Group B).

RESULTS

A total of 28 patients were included in this study. Thirteen were treated by IR techniques for prevention of first serious SRE. After a median follow-up of 48.2 months, the median TTSRE was not reached in patients treated by IR techniques and was 26.0 months in patients without IR procedures (p = .058). When comparing patients in group B, TTSRE was significantly higher in patients treated by IR (10 patients) when compared to patients without IR procedures (12 patients) (p = .021).

CONCLUSIONS

IR techniques may help to delay the occurrence of first serious SRE in patients with malignant PPM with moderate bone tumor burden disease. Prospective studies are expected to confirm these results.