Definition, Biology, and History of Oligometastatic and Oligoprogressive Disease

Effectiveness of radiotherapy in delaying treatment changes in primary or secondary immunorefractory oligoprogressive patients: preliminary results from a single-center study

AIMS

To investigate whether the addition of radiotherapy could be an appropriate option to delay the time-to-next systemic treatment (TTNsT) in patients with oligoprogressive solid tumors who had acquired or innate resistance to immune checkpoint inhibitors (ICIs).

MATERIAL AND METHODS

Patients with oligoprogressive disease treated with ICIs and radiotherapy at our Institute from January 2019 to June 2023 were retrospectively identified. Patients were stratified as primary or secondary immunorefractory according to the time of onset of ICI resistance. TTNsT and Time-To-Resistance (TTR) were the primary outcomes. Secondary outcomes included: post-radiotherapy first progression-free survival (pR-PFS), Local Control (LC), Overall Survival (OS), and treatment-related toxicities. In addition, out-of-field effects (such as the abscopal effect) of radiotherapy have been hypothesized. The survival rates were analyzed using the Kaplan-Meier method and long-rank test.

RESULTS

40 out of 105 screened patients with oligoprogressive disease met the inclusion criteria. Of these, 28 had an acquired drug resistance while 12 had an innate drug resistance. Radiotherapy was offered as a local treatment approach in all patients. RT techniques were classified into three regimens: standard palliative hypofractionated radiotherapy (hypo-RT), stereotactic radiotherapy (SRS/SBRT), and lattice radiotherapy (LRT). After a median follow-up of 22.5 months, the median TTR was 4 months (range 3-4) in patients with innate resistance vs 14 months (range 7-36) in patients with acquired resistance. Median TTNsT among patients with acquired and those with innate resistance was not reached (NR) vs 24 months (range 7-72). Overall, only six patients suffered from a local failure. Although out-of-field effects of radiotherapy were hypothesized, we were unable to record them as they did not occur during the observation period. Regardless of the radiation dose, there was no observable ≥ Grade 2 acute or late treatment-related toxicity.

CONCLUSION

Our preliminary results seem to confirm that the integration of radiotherapy and ICIs may allow for the continuation of systemic therapy beyond progression, which can have a subsequent benefit in terms of survival outcomes even in patients with innate resistance.

Safety and Efficacy of Percutaneous Cryoablation for Recurrent or Metastatic Soft Tissue Sarcoma in Adult Patients

Background: Treatment options are limited in patients with recurrent or metastatic disease after initial treatment of soft tissue sarcoma (STS) by surgical resection, radiation, or systemic therapy. Percutaneous cryoablation may provide a complementary minimally invasive option in this setting. Objective: To assess the safety and efficacy of percutaneous cryoablation performed for local control of treatment-refractory recurrent or metastatic STS. Methods: This single-institution retrospective study included adult patients who underwent percutaneous cryoablation from March 2016 to April 2023 to achieve local control of recurrent or metastatic STS after earlier treatment (surgery, radiation, or chemotherapy). For each treated lesion, a single interventional radiologist re-reviewed intraprocedural images to assess for adequate coverage by the ice ball of the entire lesion and a ≥5-mm margin in all dimensions. Complications and outcomes were extracted from medical records. The primary endpoint for procedure efficacy was 1-year local progression-free survival. Results: The study included 141 patients (median age, 66 years; 90 female, 51 male) who underwent 217 cryoablation procedures to treat 250 recurrent or metastatic STS lesions. The most common STS histologic types were leiomyosarcoma (56/141) and liposarcoma (39/141). Lesions had a mean long-axis diameter of 2.0 cm (range, 0.4-11.0 cm). Adequate ice-ball coverage was achieved for 82% (204/250) of lesions. The complication rate was 2% (4/217), entailing three major complications and one minor complication. Patients' median post-ablation follow-up was 25 months (range, 3-80 months). Local progression-free survival was 86% at 1 year and 79% at 2 years. Chemotherapy-free survival was 45% at 1 year and 31% at 2 years. Overall survival (OS) was 89% at 1 year and 80% at 2 years. In Kaplan-Meier analysis, leiomyosarcoma, in comparison with liposarcoma, had significantly higher local progression-free survival, but no significant difference in OS. In multivariable analysis, factors independently associated with an increased risk for local progression included inadequate ice-ball coverage (HR=7.73) and a lesion location of peritoneum (HR=3.63) or retroperitoneum (HR=3.71) relative to lung. Conclusion: Percutaneous cryoablation has a favorable safety and efficacy profile in patients with recurrent or metastatic STS after earlier treatments. Clinical Impact: Percutaneous cryoablation should be considered for local control of treatment-refractory STS.

Determinants of Symptomatic Intracranial Progression After an Initial Stereotactic Radiosurgery Course

Purpose

Clinical and imaging surveillance of patients with brain metastases is important after stereotactic radiosurgery (SRS) because many will experience intracranial progression (ITCP) requiring multidisciplinary management. The prognostic significance of neurologic symptoms at the time of ITCP is poorly understood.

Methods and Materials

This was a multi-institutional, retrospective cohort study from 2015 to 2020, including all patients with brain metastases completing an initial course of SRS. The primary outcome was overall survival (OS) by presence of neurologic symptoms at ITCP. OS, freedom from ITCP (FF-ITCP), and freedom from symptomatic ITCP (FF-SITCP) were assessed via Kaplan-Meier method. Cox proportional hazard models tested parameters impacting FF-ITCP and FF-SITCP.

Results

Among 1383 patients, median age was 63.4 years, 55% were female, and common primaries were non-small cell lung (49%), breast (15%), and melanoma (9%). At a median follow-up of 8.72 months, asymptomatic and symptomatic ITCP were observed in 504 (36%) and 194 (14%) patients, respectively. The majority of ITCP were distant ITCP (79.5%). OS was worse with SITCP (median, 10.2 vs 17.9 months, P < .001). SITCP was associated with clinical factors including total treatment volume (P = .012), melanoma histology (P = .001), prior whole brain radiation therapy (P = .003), number of brain metastases (P < .001), interval of 1 to 2 years from primary and brain metastasis diagnosis (P = .012), controlled extracranial disease (P = .042), and receipt of pre-SRS chemotherapy (P = .015). Patients who were younger and received post-SRS chemotherapy (P = .001), immunotherapy (P < .001), and targeted or small-molecule inhibitor therapy (P < .026) had better FF-SITCP.

Conclusions

In this cohort study of patients with brain metastases completing SRS, neurologic symptoms at ITCP is prognostic for OS. This data informs post-SRS surveillance in clinical practice as well as future prospective studies needed in the modern management of brain metastases.

The Diagnosis and Treatment Approach for Oligo-Recurrent and Oligo-Progressive Renal Cell Carcinoma

One-third of renal cell carcinomas (RCCs) without metastases develop metastatic disease after extirpative surgery for the primary tumors. The majority of metastatic RCC cases, along with treated primary lesions, involve limited lesions termed "oligo-recurrent" disease. The role of metastasis-directed therapy (MDT), including stereotactic body radiation therapy (SBRT) and metastasectomy, in the treatment of oligo-recurrent RCC has evolved. Although the surgical resection of all lesions alone can have a curative intent, SBRT is a valuable treatment option, especially for patients concurrently receiving systemic therapy. Contemporary immune checkpoint inhibitor (ICI) combination therapies remain central to the management of metastatic RCC. However, one objective of MDT is to delay the initiation of systemic therapies, thereby sparing patients from potentially unnecessary burdens. Undertaking MDT for cases showing progression under systemic therapies, known as "oligo-progression", can be complex in considering the treatment approach. Its efficacy may be diminished compared to patients with stable disease. SBRT combined with ICI can be a promising treatment for these cases because radiation therapy has been shown to affect the tumor microenvironment and areas beyond the irradiated sites. This may enhance the efficacy of ICIs, although their efficacy has only been demonstrated in clinical trials.

Local Therapies for Metastatic Sarcoma: Why, When, and How?

Management of patients with advanced sarcoma has been evolving in recent decades, from a one-fit-all perspective to a more refined, personalized, and multidisciplinary approach. In parallel, the evolution of local therapies (radiotherapy, surgical and interventional radiology techniques) has contributed to the improvement of survival of patients with advanced sarcoma. In this article, we review the evidence regarding local treatments in advanced sarcoma, as well as its integration with systemic therapies, to provide the reader a wider and deeper perspective on the management of patients with metastatic sarcoma.

Intracranial and Extracranial Progression and Their Correlation With Overall Survival After Stereotactic Radiosurgery in a Multi-institutional Cohort With Brain Metastases

Importance

Clinical trials for metastatic malignant neoplasms are increasingly being extended to patients with brain metastases. Despite the preeminence of progression-free survival (PFS) as a primary oncologic end point, the correlation of intracranial progression (ICP) and extracranial progression (ECP) events with overall survival (OS) is poorly understood for patients with brain metastases following stereotactic radiosurgery (SRS).

Objective

To determine the correlation of ICP and ECP with OS among patients with brain metastases completing an initial SRS course.

Design, Setting, and Participants

This multi-institutional retrospective cohort study was conducted from January 1, 2015, to December 31, 2020. We included patients who completed an initial course of SRS for brain metastases during the study period, including receipt of single and/or multifraction SRS, prior whole-brain radiotherapy, and brain metastasis resection. Data analysis was performed on November 15, 2022.

Exposures

Non-OS end points included intracranial PFS, extracranial PFS, PFS, time to ICP, time to ECP, and any time to progression. Progression events were radiologically defined, incorporating multidisciplinary clinical consensus.

Main Outcomes and Measures

The primary outcome was correlation of surrogate end points to OS. Clinical end points were estimated from time of SRS completion via the Kaplan-Meier method, while end-point correlation to OS was measured using normal scores rank correlation with the iterative multiple imputation approach.

Results

This study included 1383 patients, with a mean age of 63.1 years (range, 20.9-92.8 years) and a median follow-up of 8.72 months (IQR, 3.25-19.68 months). The majority of participants were White (1032 [75%]), and more than half (758 [55%]) were women. Common primary tumor sites included the lung (757 [55%]), breast (203 [15%]), and skin (melanoma; 100 [7%]). Intracranial progression was observed in 698 patients (50%), preceding 492 of 1000 observed deaths (49%). Extracranial progression was observed in 800 patients (58%), preceding 627 of 1000 observed deaths (63%). Irrespective of deaths, 482 patients (35%) experienced both ICP and ECP, 534 (39%) experienced ICP (216 [16%]) or ECP (318 [23%]), and 367 (27%) experienced neither. The median OS was 9.93 months (95% CI, 9.08-11.05 months). Intracranial PFS had the highest correlation with OS (ρ = 0.84 [95% CI, 0.82-0.85]; median, 4.39 months [95% CI, 4.02-4.92 months]). Time to ICP had the lowest correlation with OS (ρ = 0.42 [95% CI, 0.34-0.50]) and the longest median time to event (median, 8.76 months [95% CI, 7.70-9.48 months]). Across specific primary tumor types, correlations of intracranial PFS and extracranial PFS with OS were consistently high despite corresponding differences in median outcome durations.

Conclusions and Relevance

The results of this cohort study of patients with brain metastases completing SRS suggest that intracranial PFS, extracranial PFS, and PFS had the highest correlations with OS and time to ICP had the lowest correlation with OS. These data may inform future patient inclusion and end-point selection for clinical trials.

The Emerging Role of Extracranial Stereotactic Ablative Radiotherapy for Metastatic Renal Cell Carcinoma: A Systematic Review

CONTEXT

Although the management of metastatic renal cell carcinoma (mRCC) has been revolutionized by the advent of new systemic agents, still few patients experience a long-term durable response. Stereotactic ablative radiotherapy (SABR) is nowadays commonly used as metastasis-directed therapy (MDT), but limited data exist on how best to implement this strategy as part of a multimodal approach.

OBJECTIVE

To evaluate the potential role of extracranial SABR in mRCC and to identify future therapeutic developments of SABR in different disease settings.

EVIDENCE ACQUISITION

A systematic review was conducted in May 2022 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement on the PubMed database. Thirty-four studies were selected for inclusion in this systematic review.

EVIDENCE SYNTHESIS

SABR has been used with four main goals: (1) eradication of the whole metastatic burden in synchronous and metachronous oligometastatic patients, resulting in a long-term local control (LC) rate of >90% and median progression-free survival (PFS) ranging between 8 and 15 mo; (2) eradication of oligoprogressive lesions, enabling an extension of the duration of the systemic therapy by approximately 9 mo; (3) improvement of the response to systemic therapy in polymetastatic patients, resulting in an overall response rate ranging from 17% to 56%; and (4) cytoreduction in polymetastatic mRCC patients, with LC rates ranging between 71% and 100%, and preservation of the renal function, but unclear PFS and overall survival impact. Overall, the combination of SABR and systemic agents has been associated with overall good tolerance, with grade ≥3 toxicity ranging from 0% to 13%.

CONCLUSIONS

Current data highlight the role of SABR as an emerging MDT treatment option in both oligometastatic and oligoprogressive extracranial mRCC, able to ensure long-term disease control and delay the use of next-line systemic therapies. The use of SABR for cytoreduction in the de novo metastatic disease and as an immunological booster in the polymetastatic setting remains investigational and warrants further investigations.

PATIENT SUMMARY

Radiotherapy delivered with ablative doses (>6 Gy per fraction) is a promising treatment strategy for patients diagnosed with metastatic renal cell carcinoma. Excellent outcome results have been observed in patients with a limited number of metastases, improving metastasis-free survival by several months. For patients with a few metastases progressing under systemic therapy, radiotherapy allows an extension of the duration of the ongoing therapy by several months.

Prognostic Model for Intracranial Progression after Stereotactic Radiosurgery: A Multicenter Validation Study

Stereotactic radiosurgery (SRS) is a standard of care for many patients with brain metastases. To optimize post-SRS surveillance, this study aimed to validate a previously published nomogram predicting post-SRS intracranial progression (IP). We identified consecutive patients completing an initial course of SRS across two institutions between July 2017 and December 2020. Patients were classified as low- or high-risk for post-SRS IP per a previously published nomogram. Overall survival (OS) and freedom from IP (FFIP) were assessed via the Kaplan−Meier method. Assessment of parameters impacting FFIP was performed with univariable and multivariable Cox proportional hazard models. Among 890 patients, median follow-up was 9.8 months (95% CI 9.1−11.2 months). In total, 47% had NSCLC primary tumors, and 47% had oligometastatic disease (defined as ≤5 metastastic foci) at the time of SRS. Per the IP nomogram, 53% of patients were deemed high-risk. For low- and high-risk patients, median FFIP was 13.9 months (95% CI 11.1−17.1 months) and 7.6 months (95% CI 6.4−9.3 months), respectively, and FFIP was superior in low-risk patients (p < 0.0001). This large multisite BM cohort supports the use of an IP nomogram as a quick and simple means of stratifying patients into low- and high-risk groups for post-SRS IP.

Clinical value of PET/CT in identifying patients with oligometastatic/oligoprogressive disease among first-line tyrosine kinase inhibitor-treated advanced EGFR-mutant non-small cell lung cancer: Implications from survival comparisons

OBJECTIVE

Local therapy (LT) could potentially prolong the survival of patient with advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) receiving tyrosine kinase inhibitors (TKIs) and harboring oligometastatic/oligoprogressive disease (OMD/OPD). However, the optimal imaging method for identifying patients with OMD/OPD remains controversial. The objective of this study was to investigate the clinical value of incorporating PET/CT in detecting patients with OMD/OPD.

METHODS

Consecutive cases with metastatic EGFR-mutant NSCLC undergoing first-line EGFR-TKI treatment were retrospectively screened and those receiving baseline PET/CT and brain magnetic resonance imaging (MRI) or complete conventional imaging (CIM), including brain MRI, chest computed tomography (CT), abdomen ultrasound or CT and bone scintigraphy were included. OMD/OPD was defined as metastases/progressions documented at a maximum of five lesions and three organs, otherwise was defined as multiple metastatic/progressive disease (MMD/MPD). Progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

Of the 392 patients evaluated, baseline OMD was detected in 22.7% (53/233) of patients by PET/CT and in 18.2% (29/159) of patients by CIM (p = 0.171). Among the patients evaluated with baseline PET/CT, patients with OMD had longer PFS (p = 0.016) and tendency of improved OS (p = 0.058) than those with MMD. However, this result was not observed with patients evaluated using baseline CIM. With a median follow-up of 24.2 (range, 1.1-124.6) months, 297 patients had their first disease progression (FPD), of whom 164 (55.2%) had adequate imaging scans to analyze the tumor distributions at FPD comprehensively. OPD was detected in 63.0% (34/54) and 35.0% (39/110) of patients among the PET/CT and CIM assessed group (p = 0.003), respectively. Among the PET/CT assessed group, patients with OPD had significantly longer post-progressive overall survival (OS2) than those with MPD (p = 0.011). However, no significant difference of OS2 in the CIM assessed group was found.

CONCLUSION

Patients with OMD/OPD, evaluated by PET/CT but not CIM, generally had more favorable survival outcomes than those with MMD/MPD among patients with metastatic NSCLC undergoing first-line EGFR-TKI treatment.

ADVANCES IN KNOWLEDGE

PET/CT seems to affect the survival of patients under first-line EGFR-TKI treated metastatic NSCLC with OMD/OPD.

The future of PSMA PET and WB MRI as next-generation imaging tools in prostate cancer

Radiolabelled prostate-specific membrane antigen (PSMA)-based PET-CT has been shown in numerous studies to be superior to conventional imaging in the detection of nodal or distant metastatic lesions. ⁶⁸Ga-PSMA PET-CT is now recommended by many guidelines for the detection of biochemically relapsed disease after radical local therapy. PSMA radioligands can also function as radiotheranostics, and Lu-PSMA has been shown to be a potential new line of treatment for metastatic castration-resistant prostate cancer. Whole-body (WB) MRI has been shown to have a high diagnostic performance in the detection and monitoring of metastatic bone disease. Prospective, randomized, multicentre studies comparing ⁶⁸Ga-PSMA PET-CT and WB MRI for pelvic nodal and metastatic disease detection are yet to be performed. Challenges for interpretation of PSMA include tracer trapping in non-target tissues and also urinary excretion of tracers, which confounds image interpretation at the vesicoureteral junction. Additionally, studies have shown how long-term androgen deprivation therapy (ADT) affects PSMA expression and could, therefore, reduce tracer uptake and visibility of PSMA⁺ lesions. Furthermore, ADT of short duration might increase PSMA expression, leading to the PSMA flare phenomenon, which makes the accurate monitoring of treatment response to ADT with PSMA PET challenging. Scan duration, detection of incidentalomas and presence of metallic implants are some of the major challenges with WB MRI. Emerging data support the wider adoption of PSMA PET and WB MRI for diagnosis, staging, disease burden evaluation and response monitoring, although their relative roles in the standard-of-care management of patients are yet to be fully defined.

Development of the Breast Surgical Oncology Fellowship in the United States

The surgical treatment of breast cancer has rapidly evolved over the past 50 years, progressing from Halsted's radical mastectomy to a public campaign of surgical options, aesthetic reconstruction, and patient empowerment. Sparked by the research of Dr. Bernard Fisher and the first National Surgical Adjuvant Breast and Bowel Project trial in 1971, the field of breast surgery underwent significant growth over the next several decades, enabling general surgeons to limit their practices to the breast. High surgical volumes eventually led to the development of the first formal breast surgical oncology fellowship in a large community-based hospital at Baylor University Medical Center in 1982. The establishment of the American Society of Breast Surgeons, as well as several landmark clinical trials and public campaign efforts, further contributed to the advancement of breast surgery. In 2003, the Society of Surgical Oncology (SSO), in partnership with the American Society of Breast Surgeons and the American Society of Breast Disease, approved its first fellowship training program in breast surgical oncology. Since that time, the number of American fellowship programs has increased to approximately 60 programs, focusing not only on training in breast surgery, but also in medical oncology, radiation oncology, pathology, breast imaging, and plastic and reconstructive surgery. This article focuses on the happenings in the United States that led to the transition of breast surgery from a subset of general surgery to its own specialized field.

Radiosensitivity of Breast Cancer Cells Is Dependent on the Organ Microenvironment

Background

Distant metastasis is the leading risk factor of death in breast cancer patients, with lung and liver being commonly involved sites of distant seeding. Ongoing clinical trials are studying the benefit from additional local treatment to these metastatic sites with radiation therapy. However, little is known about the tissue-specific microenvironment and the modulating response to treatments due to limitations of traditional in vitro systems. By using biomatrix scaffolds (BMSs) to recreate the complex composition of extracellular matrices in normal organs, we chose to study the radiotherapy response with engineered breast cancer “metastases” in liver and lung organ-specific tissues.

Methods

Liver and lung BMSs were prepared for tissue culture. Human breast cancer cell lines were passaged on normal tissue culture plates or tissue culture plates coated with Matrigel, liver BMSs, and lung BMSs. Clonogenic assays were performed to measure cell survival with varying doses of radiation. Reactive Oxygen Species (ROS) detection assay was used to measure ROS levels after 6 Gy irradiation to cancer cells.

Results

The response of breast cell lines to varying doses of radiotherapy is affected by their in vitro acellular microenvironment. Breast cancer cells grown in liver BMSs were more radiosensitive than when grown in lung BMSs. ROS levels for breast cancer cells cultured in lung and liver BMSs were higher than that in plastic or in Matrigel plate cells, before and after radiotherapy, highlighting the interaction with surrounding tissue-specific growth factors and cytokines. ROSs in both lung and liver BMSs were significantly increased after radiotherapy delivery, suggesting these sites create prime environments for radiation-induced cell death.

Conclusions

The therapeutic response of breast cancer metastases is dependent on the organ-specific microenvironment. The interaction between tissue microenvironment in these organs may identify sensitivity of therapeutic drug targets and radiation delivery for future studies.

Current Therapy for Metastatic Head and Neck Cancer: Evidence, Opportunities, and Challenges

Management of metastatic head and neck squamous cell carcinoma is evolving as new systemic therapies have led to improvements in survival, and as advances in locoregional therapy and the increased numbers of patients with HPV-associated cancers who develop oligometastases raise the possibility of ablation of limited numbers of metastases. We review the data regarding first-line immunotherapy in PD-L1-expressing metastatic head and neck squamous cell carcinoma, the experience with aggressive local management of oligometastases, and promising novel immunotherapies, targeted therapies, and HPV-specific treatments. For patients with metastatic head and neck squamous cell carcinoma that is PD-L1 expressing, first-line systemic therapy is pembrolizumab or pembrolizumab with chemotherapy. Inclusion of chemotherapy is associated with higher objective response proportion in all biomarker subgroups and may have a greater impact on survival in HPV-associated cancers. For patients with oligometastatic disease, particularly when metastases are metachronous, current evidence supporting the role of local ablation is limited to a small number of retrospective studies. Based on retrospective data, patients with a smaller number of metastases, lung metastases, and/or virally associated head and neck squamous cell carcinoma are most likely to benefit from an aggressive ablative approach. Additionally, we review emerging evidence for targeted therapy in metastatic head and neck squamous cell carcinoma, including with agents that inhibit mutant HRAS or NOTCH1, or overexpressed EGFR. Studies of antiangiogenic agents in combination with immune checkpoint blockade, and combination immunotherapy, are also under study.

Novel Inpatient Radiation Oncology Consult Service Model Reduces Hospital Length of Stay

Palliative care and radiation therapy have played an expanding role in the management of patients with advanced cancers. Recent advances in our understanding of oligometastatic disease have led to increasing demand for familiarity with ablative techniques. Recognizing the demands of hospitalized patients for rapid access to care, we created an inpatient radiation oncology consult service (IROC) with consolidated expertise in palliative radiation and ablative techniques. In this quality improvement cohort study, we analyzed inpatient radiation oncology consults placed before and after IROC implementation and found that IROC led to increased delivery of specialty care and decreased hospital length of stay (median 8 days v 7 days, P = .005). This difference was most pronounced for patients for whom radiation therapy was indicated (14.5 v 11 days, P = .007). Our institutional experience demonstrates the value of recognizing metastatic disease as a distinct discipline and providing rapid access to palliative treatments for patients with advanced malignancies.

Metastasis-Directed Radiotherapy for Oligoprogressive or Oligopersistent Metastatic Colorectal Cancer

INTRODUCTION

Some patients with cancer may present with progressive or persistent disease at a limited number of sites following a period of treatment response. We evaluated the safety and effectiveness of metastasis-directed radiotherapy (MRT) for oligoprogressive or oligopersistent disease in patients receiving systemic treatment for metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

Patients with mCRC who received 5-fluorouracil, leucovorin, and oxaliplatin; 5-fluorouracil, leucovorin, and irinotecan; and/or capecitabine chemotherapy between 2011 and 2020 at a single institution were identified. Then, those who underwent MRT for five or fewer lesion sites while receiving systemic treatment for other metastases were categorized. The primary endpoint was time to change to systemic therapy. Secondary endpoints included MRT-related toxicity, overall survival, and local control.

RESULTS

Among 4157 patients included, 91 (2%) received MRT to limited lesion sites (55 oligoprogressive and 36 oligopersistent) during systemic treatment following a period of treatment response. The median time to change to next-line systemic therapy was 5 months in the overall cohort (measured from the current chemotherapy session) and 9.5 (range, 6.0-40.6) months in the MRT group (measured from the MRT session). No severe toxicity or systemic treatment interruption was observed following MRT. The 1-year local control and overall survival rates were 69% and 99%, respectively.

CONCLUSION

In patients with oligoprogressive or oligopersistent mCRC, MRT may be performed safely in conjunction with systemic treatment to maximize the benefit of systemic therapy and to prolong the time to change to systemic therapy. Further prospective studies should confirm these findings.

MYC levels regulate metastatic heterogeneity in pancreatic adenocarcinoma

The degree of metastatic disease varies widely amongst cancer patients and impacts clinical outcomes. However, the biological and functional differences that drive the extent of metastasis are poorly understood. We analyzed primary tumors and paired metastases using a multi-fluorescent lineage-labeled mouse model of pancreatic ductal adenocarcinoma (PDAC) - a tumor type where most patients present with metastases. Genomic and transcriptomic analysis revealed an association between metastatic burden and gene amplification or transcriptional upregulation of MYC and its downstream targets. Functional experiments showed that MYC promotes metastasis by recruiting tumor associated macrophages (TAMs), leading to greater bloodstream intravasation. Consistent with these findings, metastatic progression in human PDAC was associated with activation of MYC signaling pathways and enrichment for MYC amplifications specifically in metastatic patients. Collectively, these results implicate MYC activity as a major determinant of metastatic burden in advanced PDAC.

Narrative review: molecular and genetic profiling of oligometastatic non-small cell lung cancer

Objective

The objectives of this review are to discuss: the definition, clinical and biologic features of oligometastatic non-small cell lung cancer (NSCLC), as well as the concept of treating oligoprogression in oligometastatic NSCLC.

Background

A substantial proportion of patients diagnosed with lung cancer present with metastatic disease, and a large portion of patients who present with localized disease later develop metastases. Oligometastatic NSCLC is defined as an intermediate state between localized and widespread metastatic disease, where there may be a role for curative localized therapy approach by treating the primary tumor and all metastases with radiotherapy or surgery. Despite the increasing application of this approach in patients with lung cancer, the identification of patients who might benefit from this approach is yet to be well characterized.

Methods

After a systematic review of the literature, a PubMed search was performed using the English language and the key terms: oligometastatic, non-small cell lung cancer (NSCLC), localized consolidative treatment (LCT), biomarkers, biologic features, clinical features. Over 500 articles were retrieved between 1889–2021. A total of 178 papers discussing the definition, clinical and biologic factors leading to oligometastatic NSCLC were reviewed and included in the discussion of this paper.

Conclusions

Oligometastatic NSCLC is a unique entity. Identifying patients who have oligometastatic NSCLC accurately using a combination of clinical and biologic features and treating them with localized consolidative approach appropriately results in improvement of outcome. Further understanding of the molecular mechanisms driving the formation of oligometastatic NSCLC is an important area of focus for future studies.

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.

Exploring the role of respiratory microbiome in lung cancer: A systematic review

Giving the potential contribute in cancer initiation and progression, lung microbiota represents a promising topic in cancer research, although still unexplored. We performed a systematic literature search to identify clinical studies evaluating lung microbiota composition, its correlation with lung cancer patients' clinico-pathological features and prognosis. Of the identified 370 studies, 21 were eligible and included. Although studies were heterogeneous, lung cancer resulted to be enriched in peculiar microbial communities, with differences in composition and diversity according to clinico-pathological parameters. Few studies explored how lung microbiota influences cancer outcome. In light of these findings and borrowing the suggestions coming from gut microbiota, we speculate that respiratory microbiome may influence pathogenesis, progression and outcome of lung cancer. Taking advantage of the experience of chronical lung diseases, prospective studies should be designed to evaluate lung microbiota changes throughout any phase of lung cancer course, particularly with the advent of immunotherapy as pivotal treatment.

Oligometastatic Cancer: Key Concepts and Research Opportunities for 2021 and Beyond

Traditionally, clinicians distinguished three forms of cancer outgrowth [...].

Stereotactic ablative radiotherapy for colorectal cancer liver metastasis

Survival improvement of colorectal liver metastasis (CRLM) benefits from systemic therapy and metastasis-directed local therapy. Stereotactic ablative body radiotherapy (SABR), as a new efficient metastasis-directed local therapy with a systematic impact, plays a vital role in CRLM multidisciplinary treatment. SABR leads to a dramatic immunological change in the tumor microenvironment (TME) via differential activation of cytoprotective and cytotoxic pathways in malignant and non-malignant cells, in addition to direct tumor cell death. The synergy of SABR and immunotherapy might increase the abscopal response rate of out-field lesions by targeting different steps of the immune-mediated response, in addition to direct intratumoral cell death. The clinical treatment and efficacy of SABR, its influence on TME, and potential molecular underpinnings of which are the topic of this review.