Role of Local Ablative Therapy in Patients with Oligometastatic and Oligoprogressive Non-Small Cell Lung Cancer

Oligo-residual disease in PD-1/PD-L1 inhibitor-treated metastatic non-small cell lung cancer: incidence, pattern of failure, and clinical value of local consolidative therapy

OBJECTIVES

To investigate the feasibility and potential clinical value of local consolidative therapy (LCT) in PD-1/PD-L1 inhibitor-treated metastatic non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

PD-1/PD-L1 inhibitor-treated metastatic NSCLC patients with measurable disease in three academic centers were screened and those with adequate follow-up were included. Oligo-residual disease (ORD) was defined as residual tumors limited to three organs and five lesions evaluated at the best response among patients with partial response or stable disease after PD-1/PD-L1 inhibitors. Oligometastatic and multiple-metastatic disease (OMD/MMD) were similarly classified at baseline. Locoregional interventions, administered after effective treatment of PD-1/PD-L1 inhibitors and before initial disease progression, were defined as LCT. Patterns of initial progressive disease (PD) were classified as involving only residual sites (RP), only new sites (NP), or a combination of both (BP).

RESULTS

Among the 698 patients included, ORD was documented in 73 (47.1%) of 155 patients with baseline OMD and 60 (11.0%) of 543 patients with baseline MMD. With a median follow-up of 31.0 (range, 6.0-53.0) months, 108 patients with ORD developed initial PD, with RP, NP, and BP occurring in 51 (47%), 23 (21.3%), and 34 (31.5%), respectively. Among the 133 patients with ORD, those receiving LCT (n = 43) had longer progression-free survival (HR = 0.58, 95% CI 0.40-0.85, p = 0.01) and overall survival (HR = 0.49, 95% CI 0.30-0.79, p < 0.0001).

CONCLUSION

ORD occurs with a clinically relevant frequency among PD-1/PD-L1 inhibitor-treated metastatic NSCLC patients and LCT may provide extra survival benefits in those with ORD.

Measured Steps: Navigating the Path of Oligoprogressive Lung Cancer with Targeted and Immunotherapies

PURPOSE OF REVIEW

This review discusses the definitions, treatment modalities, management, future directions, and ongoing clinical trials of oligoprogressive disease in oncogene-driven and non-oncogene-driven NSCLC.

RECENT FINDINGS

During the last decades, diagnostic and treatment modalities for oligometastatic NSCLC have advanced significantly, leading to improved survival. Additionally, our understanding of the tumor biology of oligoprogressive disease has expanded. However, despite the efforts of organizations, such as EORTC, ESTRO, and ASTRO proposing definitions for oligometastatic and oligoprogressive disease, heterogeneity in definitions persists in (ongoing) trials. Recognizing the significance of subclassification within oligoprogressive disease in NSCLC and the varying risks associated with subsequent metastatic spread, there is a call for tailored management strategies. A consensus on standardized criteria for the definition of oligoprogressive disease is urgently needed and will not only facilitate meaningful comparisons between studies but also pave the way for the development of personalized treatment plans that take into account the heterogeneous nature of oligoprogressive disease.

Tumor hypoxia and radiotherapy: A major driver of resistance even for novel radiotherapy modalities

Hypoxia in solid tumors is an important predictor of poor clinical outcome to radiotherapy. Both physicochemical and biological processes contribute to a reduced sensitivity of hypoxic tumor cells to ionizing radiation and hypoxia-related treatment resistances. A conventional low-dose fractionated radiotherapy regimen exploits iterative reoxygenation in between the individual fractions, nevertheless tumor hypoxia still remains a major hurdle for successful treatment outcome. The technological advances achieved in image guidance and highly conformal dose delivery make it nowadays possible to prescribe larger doses to the tumor as part of single high-dose or hypofractionated radiotherapy, while keeping an acceptable level of normal tissue complication in the co-irradiated organs at risk. However, we insufficiently understand the impact of tumor hypoxia to single high-doses of RT and hypofractionated RT. So-called FLASH radiotherapy, which delivers ionizing radiation at ultrahigh dose rates (> 40 Gy/sec), has recently emerged as an important breakthrough in the radiotherapy field to reduce normal tissue toxicity compared to irradiation at conventional dose rates (few Gy/min). Not surprisingly, oxygen consumption and tumor hypoxia also seem to play an intriguing role for FLASH radiotherapy. Here we will discuss the role of tumor hypoxia for radiotherapy in general and in the context of novel radiotherapy treatment approaches.

The percutaneous management of pulmonary metastases

Local treatment of lung metastases has been in the front scene since late 90s when an international registry of thoracic surgery reported a median overall survival of 35 months in resected patients versus 15 months in non-resected patients. Today, other local therapies are available for patients with oligometastatic lung disease, including image guided thermal ablation, such as ablation, microwave ablation, and cryoablation. Image-guided ablation is increasingly offered, and now recommended in guidelines as option to surgery. Today, the size of the target tumour remains the main driver of success and selection of patients with limited tumour size allowing for local tumour control in the range of 90% in most recent and larger series targeting lung metastases up to 3.5 cm. Overall survival exceeding five-years in large series of thermal ablation for lung metastases from colorectal origin are align with outcome of same patients treated with surgical resection. Moreover, thermal ablation in such population allows for one-year chemotherapy holidays in all comers and over 18 months in lung only metastatic patients, allowing for improved patient quality of life and preserving further lines of systemic treatment when needed. Tolerance of thermal ablation is excellent and better than surgery with no lost in respiratory function, allowing for repeated treatment when needed. In the future, it is likely that practice of lung surgery for small oligometastatic lung disease will decrease, and that minimally invasive techniques will replace surgery in such indications. Randomized study will be difficult to obtain as demonstrated by discontinuation of many studies testing the hypothesis of surgery versus observation, or surgery versus SBRT.

Prognostic factors affecting survival in patients with non-small cell lung cancer treated with salvage surgery after drug therapy: a multi-institutional retrospective study

BACKGROUND

The prevalence of salvage surgeries after drug therapy for non-small cell lung cancer (NSCLC) has risen, mainly due to recent progress in molecular-targeted drugs and immune checkpoint inhibitors for NSCLC. While the safety and effectiveness of salvage surgery after drug therapy for NSCLC have been studied, its indications remain unclear. We aimed to identify the prognostic factors affecting survival in patients with advanced-stage (stages III-IV) NSCLC treated with salvage surgery after drug therapy.

METHODS

A retrospective investigation was conducted on patients who received salvage surgery after drug therapy at four hospitals between 2007 and 2020. Salvage surgery was defined as surgery after drug therapy for local progression, tumor conversion to resectable status, and discontinuation of prior drug therapy owing to serious complications.

RESULTS

Thirty-two patients received cytotoxic agents alone (n = 12 [38%]), tyrosine kinase inhibitors (TKIs; n = 16 [50%]), or immune checkpoint inhibitors (n = 4 [13%]) as prior drug therapy. In 11 (34%) and 21 (66%) patients, the clinical stage before treatment was III or IV, respectively. The median initial and preoperative serum carcinoembryonic antigen (CEA) levels were 10.2 (range, 0.5-1024) ng/mL and 4.2 (range, 0.6-92.5) ng/mL, respectively. Among the patients, 28 (88%) underwent lobectomy, 2 (6%) underwent segmentectomy, and 2 (6%) underwent wedge resection. Complete resection of the primary lesion was accomplished in 28 (88%) patients. Postoperative complications were documented in six (19%) patients. Mortality rates were 0% at 30 days and 3% at 90 days post-operation. The 5-year overall survival rate stood at 66%, while the 5-year progression-free survival rate was 21%. Multivariate analyses showed that prior TKI therapy and preoperative serum CEA level < 5 ng/mL were prognostic factors influencing overall survival (hazard ratio [95% confidence interval]: 0.06 [0.006-0.68] and 0.03 [0.002-0.41], respectively). The 5-year overall survival in the 11 patients with both favorable prognosticators was 100%.

CONCLUSIONS

In this study, prior TKI therapy and preoperative serum CEA level < 5 ng/mL were favorable prognostic factors for overall survival in patients with NSCLC treated with salvage surgery. Patients with these prognostic factors are considered good candidates for salvage surgery after drug therapy.

Image-guided thermal ablation for patients with epidermal growth factor receptor-mutant nonsmall cell lung cancer

Nonsmall cell lung cancer (NSCLC) is treated by various therapies such as surgical intervention, radiotherapy, chemotherapy, molecular targeted therapy, and immunotherapy. Currently, molecular targeted therapy, including epidermal growth factor receptor (EGFR) inhibitors and Anaplastic Lymphoma Kinase (ALK) and Kirsten Rat Sarcoma viral Oncogene (KRAS) inhibitors, has received much attention and improved the prognosis of NSCLC. Nevertheless, the terminal point of molecular targeted drugs is resistance. Drug resistance has been classified into oligoprogression and extensive progression based on the tumor lesion progression after drug resistance. There is extensive research demonstrating that local therapy (surgical resection, radiotherapy, and thermal ablation) can prolong the survival of patients with drug resistance. This review is intended to determine the efficacy of image-guided thermal ablation in patients with NSCLC with EGFR mutation.

Effectiveness of Stereotactic Ablative Radiotherapy for Systemic Therapy Respondents with Inoperable Pulmonary Oligometastases and Oligoprogression

Stereotactic ablative radiotherapy (SABR) may improve survival in patients with inoperable pulmonary oligometastases. However, the impact of pulmonary oligometastatic status after systemic therapy on SABR outcomes remains unclear. Hence, we investigated the outcomes of SABR in 45 patients with 77 lung tumors and the prognostic value of pulmonary oligoprogression. Eligibility criteria were pulmonary oligometastases (defined as ≤5 metastatic lung tumors), controlled extrapulmonary disease (EPD) after front-line systemic therapy, SABR as primary local treatment for inoperable pulmonary metastases, and consecutive imaging follow-up. Oligometastatic lung tumor was classified into controlled or oligoprogressive status. Overall survival (OS), in-field progression-free survival (IFPFS), out-field progression-free survival (OFPFS), and prognostic variables were evaluated. With 21.8 months median follow-up, the median OS, IFPFS, and OFPFS were 28.3, not reached, and 6.5 months, respectively. Two-year OS, IFPFS, and OFPFS rates were 56.0%, 74.2%, and 17.3%, respectively. Oligoprogressive status (p = 0.003), disease-free interval < 24 months (p = 0.041), and biologically effective dose (BED₁₀) < 100 Gy (p = 0.006) were independently associated with inferior OS. BED₁₀ ≥ 100 Gy (p = 0.029) was independently correlated with longer IFPFS. Oligoprogressive status (p = 0.017) and EPD (p = 0.019) were significantly associated with inferior OFPFS. Grade ≥ 2 radiation pneumonitis occurred in four (8.9%) patients. Conclusively, SABR with BED₁₀ ≥ 100 Gy could provide substantial in-field tumor control and longer OS for systemic therapy respondents with inoperable pulmonary oligometastases. Oligoprogressive lung tumors exhibited a higher risk of out-field treatment failure and shorter OS. Hence, systemic therapy should be tailored for patients with oligoprogression to reduce the risk of out-field treatment failure. However, in the absence of effective systemic therapy, SABR is a reasonable alternative to reduce resistant tumor burden.

Is stereotactic body radiotherapy an effective treatment in metastatic lung cancer with oligoprogressive disease?

BACKGROUND

Oligoprogression (OPD) is defined as a condition where limited progression (1-3 metastases) is observed in patients undergoing systemic cancer treatment. In this study we investigated the impact of stereotactic body radiotherapy (SBRT) in patients with OPD from metastatic lung cancer.

MATERIAL AND METHODS

Data from a cohort of consecutive patients with SBRT treated between June 2015 and August 2021 were collected. All extracranial metastatic sites of OPD from lung cancer were included. Dose regimens consisted of mainly 24 in 2 fractions, 30-51 Gy in 3 fractions, 30-55 Gy in 5 fractions, 52.5 Gy in 7 fractions and 44-56 Gy in 8 fractions. Kaplan-Meier method was used to calculate Overall Survival (OS), Local Control (LC), and Disease-Free Survival (DFS) from the start date of SBRT to the event.

RESULTS

Sixty-three patients, 34 female and 29 males were included. Median age was 75 years (range 25-83). All patients received concurrent systemic treatment before the start of the SBRT: 19 chemotherapy (CT), 26 CT plus immunotherapy (IT) or Tyrosin kinase inhibitors (TKI) and 18 IT/TKI. SBRT was delivered to the lung (n = 29), mediastinal node (n = 9), bone (n = 7), adrenal gland (n = 19), other visceral metastases (1) and other node metastases (n = 4). After a median follow-up of 17 months, median OS was 23 months. LC was 93% at 1 year and 87% at 2 years. DFS was 7 months. According to our results, there was no statistically significant correlation between prognostic factors and OS after SBRT in OPD patients.

CONCLUSIONS

Median DFS was 7 months, translating into the continuation of effective systemic treatment as other metastases grow slowly. In patients with oligoprogression disease, SBRT is a valid and efficient treatment that may enable postponing the switch of systemic line.

Lack of Adherence to Guideline-Based Imaging Before Subsequent Radiation in Patients with Non-Small Cell Lung Cancer: Impact on Patient Outcomes

Lung cancer is the leading cause of cancer death within the United States, yet prior studies have shown a lack of adherence to imaging and treatment guidelines in patients with lung cancer. This study evaluated the use of ¹⁸F-FDG PET/CT imaging before subsequent radiation therapy (RT) in patients with non-small cell lung cancer (NSCLC), as recommended by National Comprehensive Cancer Network guidelines, and whether the use of this imaging modality impacts cancer-specific survival. Methods: This was a retrospective study of the National Cancer Institute's Surveillance, Epidemiology, and End Results program of Medicare-linked data in patients with NSCLC. Hazard ratios and 95% CIs for overall and cancer-specific survival were estimated for patients diagnosed between 2006 and 2015 who underwent either ¹⁸F-FDG PET/CT-based or CT-based imaging before subsequent RT. Results: Significant improvement in cancer-specific survival was found in patients who underwent ¹⁸F-FDG PET/CT imaging before subsequent RT, compared with those who underwent CT (hazard ratio, 1.43 [95% CI, 1.32-1.55; P < 0.0001]). Although the National Comprehensive Cancer Network recommends ¹⁸F-FDG PET/CT before subsequent RT, 43.6% of patients were imaged with CT alone. Conclusion: Many patients with NSCLC are not being imaged according to national guidelines before subsequent RT, and this omission is associated with a lower cancer-specific survival.

Pathological complete remission in ALK-positive lung cancer patient after multiple lines of conversion therapy

Introduction

Traditional therapeutic approaches for the treatment of advanced non-small-cell lung cancer (NSCLC) are based on chemotherapy. However, the discovery and understanding of oncogenic driver alterations has led to the development of targeted therapies that have substantially improved patient outcomes. Still, to date, there have been no reports of patients with advanced anaplastic lymphoma kinase (ALK)-positive lung cancer achieving clinical complete response (cCR) in the systemic lesion and pathological complete remission (pCR) in primary lung lesion after multiple lines of conversion therapy.

Methods

In this case, a 55-year-old man was diagnosed with ALK-positive, stage IV lung adenocarcinoma using immunohistochemistry and next generation sequencing (NGS) tests.

Results

Crizotinib and two other ATP-competitive ALK inhibitors, ceritinib and alectinib, were used respectively as first-line, second-line, and third-line therapy. The patient received treatment with crizotinib and achieved partial response (PR), but 5 months later the efficacy was evaluated as progressive disease (PD). Ceritinib was used as the second-line treatment, but the disease progressed 6 months later. Alectinib was used as the third-line treatment, but the efficacy was evaluated as PD. From April 2019 to November 2019, the patient received 4 cycles of induction chemotherapy with pemetrexed/carboplatin/bevacizumab and then switched to pemetrexed/bevacizumab as the fourth-line treatment, and received the fifth line treatment, cetuximab/paclitaxel liposome/nedaplatin, for 1 cycle, but the disease still progressed. Then the patient received the sixth line of treatment, camrelizumab/lorlatinib, for 9 antitumor cycles, resulting in PR. The patient underwent surgery followed by maintenance treatment with lorlatinib and achieved cCR. To our knowledge, this is the first documented case of cCR in a patient with ALK-positive advanced lung adenocarcinoma treated with multiple lines of therapy followed by surgical treatment.

Discussion

This case reveals the possible survival benefit of immunotherapy after multiple line treatment in ALK-positive advanced lung adenocarcinoma, indicating that it is possible find new therapeutic targets based on NGS molecular detection and provide precise therapeutic strategies for clinical practice when drug resistance or progression occurs in cancer therapy.

Oligoprogression of Solid Tumors on Immune Checkpoint Inhibitors: The Impact of Local Ablative Radiation Therapy

The breakthrough of a limited number of clones while on immune checkpoint inhibitors (ICIs), known as oligoprogression, has been previously described. The benefit of ablative radiation therapy (RT) directed at these clones, as opposed to changing systemic therapy, is unclear. We analyzed 30 patients with advanced solid tumors, the majority of whom (23/30, 86.7%) had either hepatocellular or urothelial carcinoma, who experienced oligoprogression on ICIs and were referred for RT. In this study, oligoprogression was defined as having experienced progression at three or fewer metastatic sites outside of the brain after achieving at least stable disease on ICIs for a minimum of three months. The median time to oligoprogression was 11.1 months from the initiation of immunotherapy. 24 patients had one oligoprogressive lesion and six had two. The median radiation dose delivered was 4650 cGy in a median of five fractions. The median progression-free survival (PFS) after RT was 7.1 months, and the time to oligoprogression was not a significant predictor of PFS2. 26 patients continued on ICIs after RT. While 17 patients subsequently progressed, 15 did so at three or fewer metastatic sites and could have theoretically stood to benefit from an additional course of salvage RT to further extend the lifespan of their ICIs. Overall survival at 6, 12, and 24 months was 100.0%, 96.3%, and 82.8%, respectively. These results suggest that RT may provide a PFS benefit and extend the lifespan of ICIs in patients who experience oligoprogression. Regardless of PFS, however, overall survival in this population appears to be excellent.

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.

MRI-guided Radiotherapy (MRgRT) for treatment of Oligometastases: Review of clinical applications and challenges

PURPOSE

Early clinical results on the application of magnetic resonance imaging (MRI) coupled with a linear accelerator to deliver MR-guided radiation therapy (MRgRT) have demonstrated feasibility for safe delivery of stereotactic body radiotherapy (SBRT) in treatment of oligometastatic disease. Here we set out to review the clinical evidence and challenges associated with MRgRT in this setting.

METHODS AND MATERIALS

We performed a systematic review of the literature pertaining to clinical experiences and trials on the use of MRgRT primarily for the treatment of oligometastatic cancers. We reviewed the opportunities and challenges associated with the use of MRgRT.

RESULTS

Benefits of MRgRT pertaining to superior soft-tissue contrast, real-time imaging and gating, and online adaptive radiotherapy facilitate safe and effective dose escalation to oligometastatic tumors while simultaneously sparing surrounding healthy tissues. Challenges concerning further need for clinical evidence and technical considerations related to planning, delivery, quality assurance (QA) of hypofractionated doses, and safety in the MRI environment must be considered.

CONCLUSIONS

The promising early indications of safety and effectiveness of MRgRT for SBRT-based treatment of oligometastatic disease in multiple treatment locations should lead to further clinical evidence to demonstrate the benefit of this technology.

Impact of stereotactic body radiotherapy (SBRT) in oligoprogressive metastatic disease

PURPOSE

There is increasing interest in using stereotactic body radiation therapy (SBRT) in areas of oligoprogressive metastatic disease (OPD). Our main objective was to investigate the impact of SBRT on overall survival (OS) and the incidence of systemic therapy treatment switches in this population.

METHODS

A retrospective institutional review of patients treated with SBRT for OPD was performed. Patients were included if they received SBRT for 1-3 discrete progressing metastases, using a dose of at least 5 Gy per fraction. The study aimed to calculate progression-free survival (PFS), overall survival (OS), local control (LC), and incidence of treatment switch (TS). PFS and OS were calculated using the Kaplan-Meier methodology, while LC and TS were determined using cumulative incidence.

RESULTS

Eighty-one patients with a total of 118 lesions were treated with SBRT from July 2014 to November 2020. The Median SBRT dose was 40 (18-60) Gy in 5 (2-8) fractions. Patients had primarily kidney, lung, or breast cancer. Most patients were treated with a tyrosine kinase inhibitor (TKI) (30.9%) or chemotherapy (29.6%) before OPD. The median follow-up post-SBRT was 14 months. Median OS and PFS were 25.1 (95% CI 11.2-39.1) months and 7.8 (95% CI 4.6-10.9) months, respectively. The cumulative incidence of local progression of treated lesions was 5% at 1 year and 7.3% at 2 years. Sixty patients progressed after SBRT and 17 underwent additional SBRT. Thirty-eight patients (47%) changed systemic therapy following SBRT; the cumulative incidence of TS was 28.5% at 6 months, 37.4% at 1 year, and 43.9% at 2 years.

CONCLUSIONS

SBRT effectively controls locally progressing lesions but distant progression still occurs frequently. A sizeable number of patients can be salvaged by further SBRT or have minimally progressing diseases that may not warrant an immediate initiation/switch in systemic therapy. Further prospective studies are needed to validate this benefit.

The Value of Radiotherapy for Advanced Non-Small Cell Lung Cancer With Oncogene Driver-Mutation

Due to the widespread use of tyrosine kinase inhibitors (TKIs), which have largely supplanted cytotoxic chemotherapy as the first-line therapeutic choice for patients with advanced non-small cell lung cancer (NSCLC) who have oncogene driver mutations, advanced NSCLC patients with oncogene driver mutations had much long median survival. However, TKIs’ long-term efficacy is harmed by resistance to them. TKIs proved to have a limited potential to permeate cerebrospinal fluid (CSF) as well. Only a small percentage of plasma levels could be found in CSF at usual doses. Therefore, TKIs monotherapy may have a limited efficacy in individuals with brain metastases. Radiation has been demonstrated to reduce TKIs resistance and disrupt the blood-brain barrier (BBB). Previous trials have shown that local irradiation for bone metastases might improve symptoms, in addition, continuous administration of TKIs combined with radiotherapy was linked with beneficial progression-free survival (PFS) and overall survival (OS) for oligometastasis or bone metastasis NSCLC with oncogene driver mutations. The above implied that radiotherapy combined with targeted therapy may have a synergistic impact in patients with advanced oncogene driver-mutated NSCLC. The objective of this article is to discuss the value of radiotherapy in the treatment of those specific individuals.

CT-guided Percutaneous Cryoablation in Patients with Lung Nodules Mainly Composed of Ground-Glass Opacities

PURPOSE

To assess the safety and efficacy of cryoablation in patients with lung nodules mainly composed of ground-glass opacities (GGOs).

MATERIALS AND METHODS

In this retrospective study, 50 patients (mean age, 65.0 ± 12.3; 28 women) diagnosed with lung GGO nodules who underwent cryoablation were included (from June 2016-June 2021). The local recurrence rate, the incidence of regional metastases to lymph nodes, the incidence of distant metastases, adverse events, and the lung function condition were analyzed.

RESULTS

Follow-up computed tomography (CT) was performed an average of 33 months (range, 3-60 months) after the cryoablation procedure. Outcomes were only evaluated in 30 patients. A total of 20 patients were excluded: 10 patients had no cancer detected at histopathological analysis and were diagnosed with CT scan or positron emission tomography-CT (PET/CT), and the other 10 patients had nodules with a diameter of less than 10 mm and a consolidation-to-tumor ratio (CTR) of more than 0.25, and thus histopathological analysis was not performed due to small nodule size and patients were diagnosed with CT or PET/CT. The local recurrence rate was 0% (0 of 30). Evidence of regional metastases of the lymph nodes was not found in any patients (0%; 0 of 30), and the incidence of distant metastases was 0% (0 of 30). No major complications were noted. Lung function recovered to normal within one month after cryoablation in all patients.

CONCLUSION

Cryoablation may serve as a safe and feasible option for the treatment of lung nodules mainly composed of GGOs.

Role of Radiosurgery and Stereotactic Ablative Radiotherapy for Oligometastatic Non-Oncogene Addicted NSCLC

Local ablative therapy (LAT), intended as stereotactic ablative radiotherapy or stereotactic radiosurgery, is a well-recognized effective treatment for selected patients with oligometastatic NSCLC. Current clinical evidence supports LAT alone or in combination with systemic therapies. Our retrospective mono-institutional study aims to assess the role of LAT with a peculiar focus on the largest series of non-oncogene addicted oligometastatic NSCLC patients to date. We included in this analysis all patients with the mentioned disease characteristics who underwent LAT for intracranial and/or extracranial metastases between 2011 and 2020. The main endpoints were local control (LC), progression free survival (PFS) and overall survival (OS) in the whole population and after stratification for prognostic factors. We identified a series of 245 consecutive patients (314 lesions), included in this analysis (median age 69 years). In 77% of patients, a single metastasis was treated with LAT and intracranial involvement was the most frequent indication (53% of patients) in our series. The overall response rate (ORR) after LAT was 95%. In case of disease progression, 66 patients underwent new local treatments with curative intent. With a median follow-up of 18 months, median PFS was 13 months (1-year PFS 50%) and median OS was 32 months (1-year OS 75%). The median LC was not reached (1-year LC 89%). The presence of brain metastases was the only factor that negatively affected all clinical endpoints, with a 1-year LC, PFS and OS of 82%, 29% and 62% respectively, compared to 95%, 73% and 91%, respectively, for patients without BMs (p < 0.001 for each endpoint). At the multivariate analysis, mediastinal nodal involvement at baseline (p = 0.049), ECOG PS = 1 (p = 0.011), intracranial disease involvement (p = 0.001), administration of chemotherapy in combination with LAT (p = 0.020), and no delivery of further local treatment for progression or delivery of focal treatment for intracranial progression (p < 0.001) were related to a poorer OS. In our retrospective series, which is to our knowledge the largest to date, LAT showed encouraging results and confirmed the safety and effectiveness of focal treatments in non-oncogene addicted oligometastatic NSCLC patients.

Local ablative radiotherapy on oligo-progression while continued on epidermal growth factor receptor tyrosine kinase inhibitors in advanced non-small cell lung cancer patients: A longer cohort

BACKGROUND

The effect of adding local ablative radiotherapy on oligo-progression while continuing EGFR-TKIs in advanced non-small cell Lung cancer (NSCLC) patients is to be determined.

METHODS

Outcomes of patients with stage IV NSCLC harboring EGFR-activating mutations having ≤5 sites of oligo-progression while on EGFR-TKIs and given one to eight fractions of local ablative radiotherapy (LAR) were reviewed from 2012 to 2019. The time of starting first-line EGFR-TKIs to LAR is defined as progression-free survival 1 (PFS1; > one line of prior treatment allowed). The primary endpoint was PFS from LAR to further progression that led to stop of EGFR-TKIs (PFS2). The secondary endpoint was overall survival from LAR (OS). Factors affecting PFS2 and OS were analyzed with Cox regression.

RESULTS

There were total 55 eligible patients. The median follow-up time was 13.3 months. Majority (89%) had sensitive mutations (exon 19 deletion and exon 21 L858R mutation). Total number of lesions treated were 75, including lung (n = 45), bone (n = 15), cervical lymph node (n = 1), adrenal (n = 1), and brain (n = 13). The median PFS2 was 6.9 months. The median OS was 25.1 months. On multivariable analysis, it was found that EGFR mutation type (exon 19 deletion / exon 21 L858R mutation vs. other rarer mutations), time from diagnosis to LAR within 70 days, and fewer lines of prior TKIs (1 or 2 vs. 3) had favorable effect on PFS2 (p = 0.006/0.00003; 0.046; 0.001/0.005, respectively).

CONCLUSION

LAR is a noninvasive and effective modality in treatment of oligo-progressive diseases for patients with EGFR mutations positive NSCLC while on EGFR-TKIs.

Impact of Progressive Site-Directed Therapy in Oligometastatic Castration-Resistant Prostate Cancer on Subsequent Treatment Response

Simple Summary

Local treatment for oligometastatic hormone-naive prostate cancer has been shown to be effective in phase II trials. As for the efficacy of targeted therapy for oligometastatic castration-resistant prostate cancer, the results of the phase trial are not yet available, but the number of reports showing efficacy by retrospective analysis is increasing. Progressive site-directed therapy has been shown to delay the next intervention and prolong progression-free survival, but its impact on subsequent treatment efficacy and contribution to overall survival has not been reported. The purpose of this retrospective study is to evaluate the impact of progressive site-directed therapy for oligometastatic castration-resistant prostate cancer on the subsequent treatment outcomes. We found that progressive site-directed therapy was associated with better response to subsequent androgen receptor axis-targeted drugs and better overall survival. Progressive site-directed therapy for oligometastatic castration-resistant prostate cancer may improve subsequent oncological outcomes.

Abstract

The purpose of this study was to evaluate the impact of progressive site-directed therapy (PSDT) for oligometastatic castration-resistant prostate cancer (OM-CRPC) on the efficacy of subsequent androgen receptor axis-targeted (ARAT) drugs, and to demonstrate the possibility of prolonging overall survival (OS). We performed a retrospective analysis of 15 OM-CRPC patients who underwent PSDT and subsequently received first-line ARAT drugs (PSDT group) and 13 OM-CRPC patients who were treated with first-line ARAT drugs without PSDT (non-PSDT group). PSDT was performed with the intention of treating all progressing sites detected by whole-body diffusion-weighted MRI with radiotherapy. Thirteen patients (86.7%) treated with PSDT had a decrease in PSA levels, which was at least 50% in 10 (66.7%) patients. The median PSA progression-free survival (PFS) for PSDT was 7.4 months. The median PSA-PFS for ARAT was 27.2 months in patients in the PSDT group and 11.7 months in the non-PSDT group, with a significant difference between the two groups (hazard ratio [HR], 0.28; p = 0.010). The median OS was not reached in the PSDT group and was significantly longer than 44.5 months in the non-PSDT group (HR, 0.11; p = 0.014). In OM-CRPC, PSDT may improve the efficacy of subsequent ARAT and OS.

Association between oligo-residual disease and patterns of failure during EGFR-TKI treatment in EGFR-mutated non-small cell lung cancer: a retrospective study

BACKGROUND

Local ablative therapy (LAT) may be beneficial for patients with epidermal growth factor receptor (EGFR) mutated non-small cell lung cancer (NSCLC) with oligo-residual disease after treatment with EGFR tyrosine kinase inhibitor (EGFR-TKI). However, this has not been fully established. This study aimed to evaluate the predominant progressive disease (PD) pattern limited to residual sites of disease after treatment with EGFR-TKI.

METHODS

Patients with advanced EGFR-mutated NSCLC treated with EGFR-TKIs as first-line therapy were retrospectively analysed during a 7-year period. Oligo-residual disease was defined as the presence of 1 - 4 lesions (including the primary site) at 3 months from the start of EGFR-TKI treatment. The predictive factors of PD patterns after EGFR-TKI treatment were evaluated.

RESULTS

A total of 207 patients were included. Three months after the start of EGFR-TKI treatment, 66 patients (32%) had oligo-residual disease. A total of 191 patients had PD, 60 with oligo-residual disease and 131 with non-oligo-residual disease. Regarding the pattern, 44 patients (73%) with oligo-residual disease and 37 patients (28%) with non-oligo-residual disease had PD limited to the residual sites. Multivariate logistic regression analysis at 3 months from the start of EGFR-TKI treatment revealed that oligo-residual disease (P < 0.001), the lack of residual central nervous system metastases (P = 0.032), and initial treatment with osimertinib (P = 0.028) were independent predictors of PD limited to residual disease sites.

CONCLUSIONS

This study provided a rationale for LAT to all sites of residual disease in patients with oligo-residual disease during EGFR-TKI treatment.

Long-Term Survival After Salvage Thoracic Surgery on a Patient with ALK-Rearranged Metastatic Lung Adenocarcinoma After Progression on Targeted Therapy

Targeted therapy for patients with advanced non-small cell lung cancer (NSCLC) is often challenged by the arising of drug resistance. After progression to targeted therapy, treatment options include continued targeted therapy, definitive local therapy, and the combination of both. While there is evidence that local ablative radiotherapy may prolong the disease control by targeted therapy, little is known regarding the relevance of salvage thoracic surgery in this setting. Herein, we presented a case of stage IV lung adenocarcinoma with concurrent EML4-ALK and TAC1-ALK fusion who had long-term survival after salvage thoracic surgery. The patient underwent a multidisciplinary treatment scheme that consisted of radiotherapy, ALK inhibitor crizotinib, and surgery, with blood-based genomic profiling for monitoring disease progression. Notably, salvage thoracic surgery was performed after progression on the crizotinib therapy and acquired ALK F1174C mutation was identified, which has been shown to be resistant to crizotinib and possibly sensitive to ceritinib. The patient benefited from salvage thoracic surgery with a remarkable progression-free survival of 31 months at last follow-up, and the patient maintained high-performance status throughout the course of management. To the best of our knowledge, this is the first case reporting on the long-term survival outcome from salvage thoracic surgery after crizotinib treatment in an NSCLC patient carrying double ALK fusion.

Phase II study of multidisciplinary therapy combined with pembrolizumab for patients with synchronous oligometastatic non-small cell lung cancer TRAP OLIGO study (WJOG11118L)

Background

Synchronous oligometastatic non-small cell lung cancer (NSCLC) is generally characterised by the limited number of metastases at the time of diagnosis. Several clinical trials have shown that local ablative therapy (LAT) at all sites of the disease might be beneficial for patients with oligometastatic NSCLC. In recent years, the combination of programmed cell death 1 (PD-1) inhibitors or programmed cell death ligand 1 with cytotoxic chemotherapy has become a new standard treatment for patients with metastatic NSCLC. Furthermore, multisite LAT would inherently reduce the overall tumour burden, and this could promote T cell reinvigoration to enhance the efficacy of PD-1 inhibitors. Few studies have evaluated the efficacy of the combination of PD-1 inhibitors with LAT at all sites of disease. The aim of the present multicentre single-arm phase II study is to evaluate the efficacy of LAT at all sites of disease following standard platinum doublet chemotherapy with pembrolizumab in patients with oligometastatic NSCLC.

Methods

Thirty patients with synchronous oligometastatic NSCLC will be enrolled in the trial. All patients will receive 2–4 cycles of a systemic treatment including pembrolizumab and chemotherapy as induction therapy. Patients who will receive LAT will be determined by a multidisciplinary tumour board, including medical oncologists, radiation oncologists, and thoracic surgeons. LAT will be administered at all sites of disease within 21–56 days of the last dose of induction therapy and will be followed by maintenance therapy within 42 days of the last day of LAT. The primary endpoint is the progression-free survival (PFS) rate of 24 months from the date of initiation of LAT. The secondary endpoints are toxicity, response to induction therapy, PFS, overall survival, and the frequency of LAT.

Discussion

This study will provide novel data on the efficacy and safety profile of the combination of LAT and chemotherapy plus immune-checkpoint inhibitors in patients with synchronous oligometastatic NSCLC. If the primary endpoint of this study is met, extensive phase III studies further assessing this strategy will be recommended.

Trial registration

jRCT identifier: jRCTs041200046 (date of initial registration: 28 October 2020).

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

The role of surgery in the treatment of oligoprogression after systemic treatment for advanced non-small cell lung cancer

OBJECTIVES

Patients with advanced stage non-small cell lung cancer (NSCLC) are generally considered incurable. The mainstay of treatment for these patients is systemic therapy. The addition of local treatment, including surgery, remains controversial. Oligoprogression is defined as advanced stage NSCLC with limited progression of disease after a period of prolonged disease stabilisation or after a partial or complete response on systemic therapy. In this retrospective study we evaluated outcome and survival of patients who underwent a resection for oligoprogression after systemic therapy for advanced stage NSCLC.

MATERIALS AND METHODS

Patients with oligoprogression after systemic treatment for advanced NSCLC who were operated in the Antoni van Leeuwenhoek Hospital were included. Patient and treatment characteristics were collected in relation to progression free survival (PFS) and overall survival (OS).

RESULTS

Between January 2015 and December 2019, 28 patients underwent surgery for an oligoprogressive lesion (primary tumor lung (n = 12), other metastatic site (n = 16)). Median age at time of resection was 60 years (39-86) and 57% were female. Postoperative complications were observed in 2 patients (7%). Progression of disease after resection of the oligoprogressive site was observed in 17 patients (61%). Median PFS was 7 months since date of resection (95% CI 6.0-25.0) and median OS was not reached. Seven patients (25%) died during follow-up. Age was predictive for OS and clinical T4 stage was predictive for PFS. M1 disease at initial presentation was predictive for better PFS compared to patients who were diagnosed with M0 disease initially. Patients who underwent resection because of oligoprogression of the primary lung tumour had a better PFS, when compared to oligoprogression of another metastastic site.

CONCLUSION

Surgical resection of an oligoprogressive lesion in patients with advanced NSCLC treated with systemic treatment is feasible and might be considered in order to achieve long term survival.

Surgical Survival Benefits With Different Metastatic Patterns for Stage IV Extrathoracic Metastatic Non-Small Cell Lung Cancer: A SEER-Based Study

Background:

With the knowledge of oligometastases, primary surgery plays an increasingly vital role in metastatic non-small cell lung cancer. We aimed to evaluate the survival benefit of primary surgery based on metastatic patterns.

Materials and Methods:

The selected patients with stage IV extrathoracic metastatic (m1b) non-small cell lung cancer between 2010 and 2015 were included in a retrospective cohort study from the Surveillance, Epidemiology, and End Results (SEER) database. Multiple imputation was used for the missing data. Patients were divided into 2 groups depending on whether surgery was performed. After covariate balancing propensity score (CBPS) weighting, multivariate Cox regression models and Kaplan-Meier survival curve were built to identify the survival benefit of different metastatic patterns.

Results:

Surgery can potentially increase the overall survival (OS) (adjusted HR: 0.68, P < 0.001) of non-small cell lung cancer. The weighted 3-year OS in the surgical group was 16.9%, compared with 7.8% in the nonsurgical group. For single organ metastasis, surgery could improve the survival of metastatic non-small cell lung cancer. Meanwhile, no significant survival improvements in surgical group were observed in patients with multiple organ metastases.

Conclusion:

The surgical survival benefits for extrathoracic metastatic non-small cell lung cancer could be divided by metastatic pattern.

A narrative review on tumor microenvironment in oligometastatic and oligoprogressive non-small cell lung cancer: a lot remains to be done

Objective

In this review, we aim to collect and discuss available data about the role and composition of tumor microenvironment (TME) in oligometastatic (OMD) and oligoprogressive (OPD) non-small cell lung cancer (NSCLC). Furthermore, we aim to summarize the ongoing clinical trials evaluating as exploratory objective the TME composition, through tissue and/or blood samples, in order to clarify whether TME and its components could explain, at least partially, the oligometastatic/oligoprogressive process and could unravel the existence of predictive and/or prognostic factors for local ablative therapy (LAT).

Background

OMD/OPD NSCLC represent a heterogeneous group of diseases. Several data have shown that TME plays an important role in tumor progression and therefore in treatment response. The crucial role of several types of cells and molecules such as immune cells, cytokines, integrins, protease and adhesion molecules, tumor-associated macrophages (TAMs) and mesenchymal stem cells (MSCs) has been widely established. Due to the peculiar activation of specific pathways and expression of adhesion molecules, metastatic cells seem to show a tropism for specific anatomic sites (the so-called “seed and soil” hypothesis). Based on this theory, metastases appear as a biologically driven process rather than a random release of cancer cells. Although the role and the function of TME at the time of progression in patients with NSCLC treated with tyrosine-kinase inhibitors and immune checkpoint inhibitors (ICIs) have been investigated, limited data about the role and the biological meaning of TME are available in the specific OMD/OPD setting.

Methods

Through a comprehensive PubMed and ClinicalTrials.gov search, we identified available and ongoing studies exploring the role of TME in oligometastatic/oligoprogressive NSCLC.

Conclusions

Deepening the knowledge on TME composition and function in OMD/OPD may provide innovative implications in terms of both prognosis and prediction of outcome in particular from local treatments, paving the way for future investigations of personalized approaches in both advanced and early disease settings.

Case Report: Abscopal Effect of Microwave Ablation in a Patient With Advanced Squamous NSCLC and Resistance to Immunotherapy

Currently, immunotherapy has been a backbone in the treatment of advanced non-small cell lung cancer (NSCLC) without driver gene mutations. However, only a small proportion of NSCLC patients respond to immune checkpoint inhibitors, and majority of patients with initial response will develop acquired resistance at 5 years, which usually manifests as oligo-progression or oligo-metastases. Evidence from multiple clinical trials indicates that local consolidative therapies could improve the prognosis of oligometastatic NSCLC patients. Herein, we reported a case of advanced squamous lung cancer which showed a durable abscopal effect from microwave ablation after acquired resistance of immunotherapy.

The Role of Surgery in Lung Cancer Treatment: Present Indications and Future Perspectives-State of the Art

Non-small cell lung cancers (NSCLC) are different today, due to the increased use of screening programs and of innovative systemic therapies, leading to the diagnosis of earlier and pre-invasive tumors, and of more advanced and controlled metastatic tumors. Surgery for NSCLC remains the cornerstone treatment when it can be performed. The role of surgery and surgeons has also evolved because surgeons not only perform the initial curative lung cancer resection but they also accompany and follow-up patients from pre-operative rehabilitation, to treatment for recurrences. Surgery is personalized, according to cancer characteristics, including cancer extensions, from pre-invasive and local tumors to locally advanced, metastatic disease, or residual disease after medical treatment, anticipating recurrences, and patients' characteristics. Surgical management is constantly evolving to offer the best oncologic resection adapted to each NSCLC stage. Today, NSCLC can be considered as a chronic disease and surgery is a valuable tool for the diagnosis and treatment of recurrences, and in palliative conditions to relieve dyspnea and improve patients' comfort.

Future Directions in the Use of SAbR for the Treatment of Oligometastatic Cancers

The role of local therapy as a sole therapy or part of a combined approach in treating metastatic cancer continues to evolve. The most obvious requirements for prudent implementation of local therapies like stereotactic ablative radiotherapy (SAbR) to become mainstream in treating oligometastases are (1) Clear guidance as to what particular patients might benefit, and (2) Confirmation of improvements in outcome after such treatments via clinical trials. These future directional requirements are non-negotiable. However, innovation and research offer many more opportunities to understand and improve therapy. Identifying candidates and personalizing their therapy can be afforded via proteomic, genomic and epigenomic characterization techniques. Such molecular profiling along with liquid biopsy opportunities will both help select best therapies and facilitate ongoing monitoring of response. Technologies both to find targets and help deliver less-toxic therapy continue to improve and will be available in the marketplace. These technologies include molecular-based imaging (eg, PET-PSMA), FLASH ultra-high dose rate platforms, Grid therapy, PULSAR adaptive dosing, and MRI/PET guided linear accelerators. Importantly, a treatment approach beyond oligometastastic could evolve including a rationale for using SAbR in the oligoprogressive, oligononresponsive, oligobulky and oligolethal settings as well as expansion beyond oligo- toward even plurimetastastic disease. In any case, lessons learned and experiences required by the implementation of using SAbR in oligometastatic cancer will be revisited.

Combined with interventional therapy, immunotherapy can create a new outlook for tumor treatment

Recent progress in immunotherapy provides hope of a complete cure to cancer patients. However, recent studies have reported that only a limited number of cancer patients with a specific immune status, known as "cold tumor", can benefit from a single immune agent. Although the combination of immune agents with different mechanisms can partially increase the low response rate and improve efficacy, it can also result in more side effects. Therefore, discovering therapies that can improve tumors' response rate to immunotherapy without increasing toxicity for patients is urgently needed. Tumor interventional therapy is promising. It mainly includes transcatheter arterial chemoembolization, ablation, radioactive particle internal irradiation, and photodynamic interventional therapy based on a luminal stent. Interventional therapy can directly kill tumor cells by targeted drug delivery in situ, thus reducing drug dosage and systemic toxicity like cytokine release syndrome. More importantly, interventional therapy can regulate the immune system through numerous mechanisms, making it a suitable choice for immunotherapy to combine with. In this review, we provide a brief description of immunotherapies (and their side effects) on tumors of different immune types and preliminarily elaborate on interventional therapy mechanisms to improve immune efficacy. We also discuss the progress and challenges of the combination of interventional therapy and immunotherapy.

Definition, Biology, and History of Oligometastatic and Oligoprogressive Disease

Historical theories of metastasis have been informed by the seed and soil hypothesis, the Halsteadian paradigm proposing an orderly spread from local to distant sites, and the presumption that cancer is an inherently systemic process even in the earliest cases. The more contemporary spectrum theory now suggests that the propensity for distant spread exists along a continuum of metastatic virulence. Tumors with limited metastatic potential represent one subset along this spectrum that could potentially be cured with local ablative therapy. Integrating clinical and molecular features to biologically inform the classification of not only oligometastatic or oligoprogressive disease but also the entire metastatic spectrum holds great promise to improve prognostication and inform clinical decision making. To this end, the inclusion of molecular correlative studies and biospecimen collection on prospective protocols is imperative.

Management of Oligometastasis and Oligoprogression in Patients with Epidermal Growth Factor Receptor Mutation-Positive NSCLC in the Era of Third-Generation Tyrosine Kinase Inhibitors

This review covers the importance of local consolidative therapy (LCT) in patients with epidermal growth factor receptor (EGFR) mutation-positive with oligometastatic and oligoprogressive non-small-cell lung cancer (NSCLC). With the advent of third-generation EGFR tyrosine kinase inhibitors, a more updated review is necessary. We review the efficacy of LCT, pathophysiological background, and treatment modalities other than radiotherapy. In addition, we also discussed when and how LCT should be applied to patients with oligometastatic and oligoprogressive NSCLC.

Beyond First-Line Immunotherapy: Potential Therapeutic Strategies Based on Different Pattern Progressions: Oligo and Systemic Progression

First-line immune-checkpoint inhibitor (ICI)-based therapy has deeply changed the treatment landscape and prognosis in advanced non-small cell lung cancer (aNSCLC) patients with no targetable alterations. Nonetheless, a percentage of patients progressed on ICI as monotherapy or combinations. Open questions remain on patients' selection, the identification of biomarkers of primary resistance to immunotherapy and the treatment strategies to overcome secondary resistance to first-line immunotherapy. Local ablative approaches are the main therapeutic strategies in oligoprogressive disease, and their role is emerging in patients treated with immunotherapy. Many therapeutic strategies can be adapted in aNSCLC patients with systemic progression to personalize the treatment approach according to re-characterization of the tumors, previous ICI response, and type of progression. This review's aim is to highlight and discuss the current and potential therapeutic approaches beyond first-line ICI-based therapy in aNSCLC patients based on the pattern of disease progression (oligoprogression versus systemic progression).

Post-progression outcomes of NSCLC patients with PD-L1 expression ≥ 50% receiving first-line single-agent pembrolizumab in a large multicentre real-world study

BACKGROUND

Treatment sequencing with first-line immunotherapy, followed by second-line chemotherapy, is still a viable option for NSCLC patients with PD-L1 expression ≥50%.

METHODS

We evaluated post-progression treatment pathways in a large real-world cohort of metastatic NSCLC patients with PD-L1 expression ≥ 50% treated with first-line pembrolizumab monotherapy.

RESULTS

Overall, 974 patients were included. With a median follow-up of 22.7 months (95%CI: 21.6-38.2), the median overall survival (OS) of the entire population was 15.8 months (95%CI: 13.5-17.5; 548 events). At the data cutoff, among the 678 patients who experienced disease progression, 379 (55.9%) had not received any further treatment, and 359 patients (52.9%) had died. Patients who did not receive post-progression therapies were older (p = 0.0011), with a worse ECOG-PS (p < 0.0001) and were on corticosteroids prior to pembrolizumab (p = 0.0024). At disease progression, 198 patients (29.2%) received a switched approach and 101 (14.9%) received pembrolizumab ByPD either alone (64 [9.4%]) or in combination with local ablative treatments (37 [5.5%]) (LATs). After a random-case control matching according to ECOG-PS, CNS metastases, bone metastases, and (previous) best response to pembrolizumab, patients receiving pembrolizumab ByPD plus LATs were confirmed to have a significantly longer post-progression OS compared to patients receiving pembrolizumab ByPD alone 13.9 months versus 7.8 months (p = 0.0179) 241 patients (35.5%) among the 678 who had experienced PD, received a second-line systemic treatment (regardless of previous treatment beyond PD). As compared to first-line treatment commencement, patients' features at the moment of second-line initiation showed a significantly higher proportion of patients aged under 70 years (p = 0.0244), with a poorer ECOG-PS (p < 0.0001) and having CNS (p = 0.0001), bone (p = 0.0266) and liver metastases (p = 0.0148).

CONCLUSIONS

In the real-world scenario NSCLC patients with PD-L1 expression ≥50% treated with first-line single-agent pembrolizumab achieve worse outcomes as compared to the Keynote-024 trial. Poor post-progression outcomes are major determinants of the global results that should be considered when counselling patients for first-line treatment choices.

Progression Patterns, Treatment, and Prognosis Beyond Resistance of Responders to Immunotherapy in Advanced Non-Small Cell Lung Cancer

Introduction

Immune checkpoint inhibitors (ICIs) have changed the management of non-small cell lung cancer (NSCLC). However, resistance is inevitable. The disease progression patterns, sequential treatment, and prognosis beyond ICI resistance are not completely understood.

Methods

We retrospectively analyzed stage IV NSCLC patients who underwent ICI treatment at Zhejiang Cancer Hospital between January 2016 and January 2020 and who suffered disease progression after at least stable disease on immunotherapy for more than 3 months (at least two cycles). Oligoprogression and systematic progression were defined as previous reports. The main outcome measures were progression-free survival (PFS), second PFS (PFS2), and overall survival (OS). Survival curves were plotted using the Kaplan-Meier method. The Cox proportional hazards model was used for multivariate analysis.

Results

Totally 1,014 NSCLC patients were administered immunotherapy. Of them, 208 NSCLC patients were included in this retrospective study. The estimated PFS, PFS2 and OS were 6.3 months (95% CI 5.6–7.0 months), 10.7 months (95% CI 10.1–12.7 months), and 21.4 months (95% CI 20.6–26.4 months), respectively. After resistance, 55.3% (N = 115) patients developed oligoprogression, and 44.7% (N = 93) systemic progression. For patients with systemic progression, chemotherapy (N = 35, 37.6%), best supportive care (N = 30, 32.3%), and antiangiogenic therapy alone (N = 11, 11.8%) were the major strategies. A combination of local radiotherapy (N = 38, 33.0%) with continued ICIs was the most common treatment used in oligoprogression group, followed by continued immunotherapy with antiangiogenic therapy (N = 19, 16.5%) and local radiotherapy only (N = 17, 14.9%). For patients with oligoprogression, continued immunotherapy plus local radiotherapy can lead to a significantly longer PFS2 (12.9 vs. 10.0 months; p = 0.006) and OS (26.3 vs. 18.5 months, p = 0.001). The PFS2 and OS of patients with oligoprogression were superior to those of patients with systemic progression (PFS2: 13.1 vs. 10.0 months, p = 0.001; OS: 25.8 vs. 19.1 months, p = 0.003).

Conclusions

The major progression pattern after acquired resistance from immunotherapy is oligoprogression. Local radiotherapy with continued immunotherapy beyond oligoprogression in responders was feasible and led to prolonged PFS2 and OS in advanced NSCLC patients.

Efficacy of Local Therapy for Oligometastatic Hepatocellular Carcinoma: A Propensity Score Matched Analysis

Purpose

With respect to various solid cancers, patients with oligometastasis may benefit from local therapy. However, this approach is not widely accepted for hepatocellular carcinoma. This study investigated the efficacy of local therapy for oligometastatic lesions in patients with hepatocellular carcinoma.

Patients and Methods

The study included 69 hepatocellular carcinoma patients presenting with oligometastasis to the lung. Characteristics of the patients and treatment options for metastatic lesions were reviewed, and a survival analysis was performed. After propensity score matching, overall survival and progression-free survival were calculated from the time of pulmonary metastasis detection. Factors predicting prognosis were analyzed using a multivariate Cox regression analysis.

Results

After propensity score matching, 58 patients with Child-Pugh grade A disease were selected. Among them, 22 patients were treated with systemic therapy alone while 36 patients received local therapy or a combination of local and systemic therapies for metastatic lesions. Survival rates were higher in patients receiving local therapy than in those receiving systemic therapy (2-year overall survival rate, 66.6 vs 31.2%, p<0.001; 2-year progression-free survival rate, 47.0 vs 10.6%, p=0.005). In the multivariate Cox regression analysis, alpha-fetoprotein levels less than 400 ng/mL and the use of local therapy for metastatic lesions were found to be significant favorable prognostic factors.

Conclusion

Local therapy for metastatic lesions improved the oncologic outcomes of patients with hepatocellular carcinoma with pulmonary oligometastasis.

Radiogenomics in Interventional Oncology

PURPOSE OF REVIEW

Radiogenomics is a growing field that has garnered immense interest over the past decade, owing to its numerous applications in the field of oncology and its potential value in improving patient outcomes. Current applications have only begun to delve into the potential of radiogenomics, and particularly in interventional oncology, there is room for development and increased value of these applications.

RECENT FINDINGS

The field of interventional oncology (IO) has seen valuable radiogenomic applications, from prediction of response to locoregional therapies in hepatocellular carcinoma to identification of genetic mutations in non-small cell lung cancer. Future directions that can increase the value of radiogenomics include applications that address tumor heterogeneity, predict immune responsiveness of tumors, and differentiate between oligoprogression and early widespread progression, among others. Radiogenomics, whether in terms of methodologies or applications, is still in the early stages of development and far from maturation. Future applications, particularly in the field of interventional oncology, will allow realization of its full potential.

Proposing synchronous oligometastatic non-small-cell lung cancer based on progression after first-line systemic therapy

Despite the importance of accurate disease definitions for effective management and treatment decisions, there is currently no consensus on what constitutes oligometastatic non–small‐cell lung cancer (NSCLC). Predominant patterns of initial progressive disease (PD) after first‐line systemic therapy have been shown to be a substantial basis for local ablative therapy (LAT) for all disease sites in patients with oligometastatic NSCLC, suggesting that these patterns could be helpful in defining synchronous oligometastatic NSCLC. Therefore, this retrospective study aimed to propose a threshold number of metastases for synchronous oligometastatic NSCLC, based on the pattern of initial PD after first‐line systemic therapy. The cut‐off threshold number of metastases compatible with synchronous oligometastatic NSCLC was determined using receiver operating characteristic (ROC) curve analyses of PD at the initially involved sites alone. ROC analysis of 175 patients revealed that the presence of 1‐3 metastases before first‐line treatment (sensitivity, 85.9%; specificity, 97.3%; area under the curve, 0.91) was compatible with oligometastatic NSCLC, therefore we divided patients into oligometastatic NSCLC and non‐oligometastatic NSCLC groups. Multivariate logistic regression analyses revealed oligometastatic NSCLC to be the only independent predictor of PD at initially involved sites alone (odds ratio 165.7; P < .001). The median survival times in patients with oligometastatic or non‐oligometastatic NSCLC were 23.0 and 10.9 mo (hazard ratio, 0.51; P = .002), respectively. Based on these findings, we propose synchronous oligometastatic NSCLC as 1‐3 metastases in accordance with patterns of initial progression. The result of our study might be contributory to provide a common definition of synchronous oligometastatic NSCLC.

[Advances and Challenges of Local Thermal Ablation in Non-small Cell Lung Cancer]

非小细胞肺癌（non-small cell lung cancer, NSCLC）是原发性肺癌的主要类型，手术切除、放化疗、靶向治疗及免疫治疗等是其主要的治疗模式。近年来，热消融在各期NSCLC的临床应用中受到越来越多的关注。热消融作为一种安全、高效的局部治疗手段，合理的临床应用可以给NSCLC患者带来更多的临床获益。然而其在NSCLC中的应用仍然存在许多尚待研究探讨的问题。本文对近年来热消融在NSCLC中的应用现状作以综述，旨在探讨目前存在的争议问题和未来研究方向。

Lung-molGPA Index Predicts Survival Outcomes of Non-Small-Cell Lung Cancer Patients with Synchronous or Metachronous Brain Metastases

Background

Graded prognostic assessment for lung cancer using molecular markers (Lung-molGPA) for brain metastases is a powerful prognostic tool. However, it has not been validated for non-small-cell lung cancer (NSCLC) patients with synchronous or metachronous brain metastases.

Methods

A total of 1184 NSCLC patients with synchronous or metachronous brain metastases were reviewed in this study. Comparative clinicopathological variables and survival analysis for these two groups (synchronous vs metachronous), as well as complimentary analysis of prognostic factors for the entire patient cohort, were performed. Afterward, patients were stratified using Lung-molGPA to evaluate the accuracy of the survival estimates.

Results

A total of 763 patients (64.4%) had synchronous metastases while 35.6% (421 patients) had metachronous metastasis. Patients with synchronous metastases were more likely to have a smoking history, limited metastatic lesions, and absence of cerebral symptoms (P<0.05). Patients with metachronous metastatic NSCLC had an overall survival (OS) period of 16.5 (95% CI 14.5–18.6) months and were longer compared to patients with synchronous metastases (16.5 vs 13.5 [12.5–14.6] months, P=0.004). In Cox regression multivariable analysis, age (HR=1.25, P=0.008), Karnofsky performance status (HR=1.30, P=0.005), extracranial metastases (HR=1.57, P<0.001), number of brain metastases (HR=1.22, P=0.043), gene mutation (HR=1.40 [wild type vs mutation], P=0.050; HR=1.42 [unknown vs mutation], P=0.007), and treatment (including TKI, chemotherapy, and local brain treatment, P<0.05) were independent prognostic predictors of OS. Additionally, metachronous metastatic patients were at lower risk for disease-related death compared to synchronous metastatic patients (HR=0.69, P<0.001). Importantly, median OS stratified by Lung-molGPA of 0–1, 1.5–2, 2.5–3 and 3.5–4 scores were 11.0, 14.0, 24.9, and 26.3 months for synchronous brain metastases, and 13.1, 17.0, 37.2, and 66.5 months for metachronous metastases, respectively (P<0.001).

Conclusion

Lung-molGPA could estimate the prognosis of NSCLC patients with synchronous or metachronous brain metastases. Hence, patients should be carefully stratified for consideration of aggressive therapy.

Risk stratification of EGFR+ lung cancer diagnosed with panel-based next-generation sequencing

OBJECTIVE

Panel-based next-generation sequencing (NGS) is increasingly used for the diagnosis of EGFR-mutated non-small-cell lung cancer (NSCLC) and could improve risk assessment in combination with clinical parameters.

MATERIALS AND METHODS

To this end, we retrospectively analyzed the outcome of 400 tyrosine kinase inhibitor (TKI)-treated EGFR⁺ NSCLC patients with validation of results in an independent cohort (n = 130).

RESULTS

EGFR alterations other than exon 19 deletions (non-del19), TP53 co-mutations, and brain metastases at baseline showed independent associations of similar strengths with progression-free (PFS hazard ratios [HR] 2.1-2.3) and overall survival (OS HR 1.7-2.2), in combination defining patient subgroups with distinct outcome (EGFR⁺NSCLC risk Score, "ENS", p < 0.001). Co-mutations beyond TP53 were rarely detected by our multigene panel (<5%) and not associated with clinical endpoints. Smoking did not affect outcome independently, but was associated with non-del19 EGFR mutations (p < 0.05) and comorbidities (p < 0.001). Laboratory parameters, like the blood lymphocyte-to-neutrophil ratio and serum LDH, correlated with the metastatic pattern (p < 0.01), but had no independent prognostic value. Reduced ECOG performance status (PS) was associated with comorbidities (p < 0.05) and shorter OS (p < 0.05), but preserved TKI efficacy. Non-adenocarcinoma histology was also associated with shorter OS (p < 0.05), but rare (2-3 %). The ECOG PS and non-adenocarcinoma histology could not be validated in our independent cohort, and did not increase the range of prognostication alongside the ENS.

CONCLUSIONS

EGFR variant, TP53 status and brain metastases predict TKI efficacy and survival in EGFR⁺ NSCLC irrespective of other currently available parameters ("ENS"). Together, they constitute a practical and reproducible approach for risk stratification of newly diagnosed metastatic EGFR⁺ NSCLC.

Management of Non-Small-Cell Lung Cancer Patients Initially Diagnosed With 1 to 3 Synchronous Brain-Only Metastases: A Retrospective Study

BACKGROUND

The treatment options for newly diagnosed non-small-cell lung cancer (NSCLC) patients with 1 to 3 synchronous brain metastases (BM) remain controversial. The current study aimed to comprehensively analyze the characteristics, local treatment paradigms, and survival outcomes in these populations.

PATIENTS AND METHODS

A total of 252 NSCLC patients initially diagnosed with 1 to 3 synchronous brain-only metastases were enrolled onto this study. Local therapy (LT) to primary lung tumors (PLT) and BM included surgery, radiotherapy, or both. Median overall survival (mOS) was measured among patients who received LT to both PLT and BM (all-LT group), patients who were treated with LT to either PLT or BM (part-LT group), and patients who did not receive any LT (non-LT group).

RESULTS

The mOS for all-LT (n = 70), part-LT (n = 113), and non-LT (n = 69) groups was 33.2, 18.5, and 16.8 months, respectively (P = .002). The OS rates at 5 years for the all-LT, part-LT, and non-LT groups were 25.5%, 16.2%, and 0, respectively. Multivariable analysis revealed that all-LT versus non-LT, pretreatment Karnofsky performance status > 70, histology of adenocarcinoma, thoracic stage I-II, EGFR mutation, ALK positive, and second-line systemic therapies were independent prognostic factors for improved mOS.

CONCLUSIONS

The current study showed that LT for both PLT and BM is associated with superior OS in appropriately selected NSCLC patients initially diagnosed with 1 to 3 synchronous BM. Prospective trials are urgently needed to confirm this finding.

Resistance to immune checkpoint inhibitors in non-small cell lung cancer: biomarkers and therapeutic strategies

The treatment landscape for patients with advanced non-small cell lung cancer has evolved greatly with the advent of immune checkpoint inhibitors. However, many patients do not derive benefit from checkpoint blockade, developing either primary or secondary resistance, highlighting a need for alternative approaches to modulate immune function. In this review, we highlight the absence of a common definition of primary and secondary resistance and summarize their frequency and clinical characteristics. Furthermore, we provide an overview of the biomarkers and mechanisms of resistance involving the tumor, the tumor microenvironment and the host, and suggest treatment strategies to overcome these mechanisms and improve clinical outcomes.

Metastasis-directed Therapy Prolongs Efficacy of Systemic Therapy and Improves Clinical Outcomes in Oligoprogressive Castration-resistant Prostate Cancer

BACKGROUND

Available therapies for castrate-resistant prostate cancer (CRPC) confer minimal survival advantage; thus, there is interest in metastasis-directed therapy (MDT) for oligometastatic or oligoprogressive disease to improve outcomes. Here, we describe outcomes of oligoprogressive CRPC treated with stereotactic ablative radiotherapy (SABR).

OBJECTIVE

To report outcomes of oligoprogressive CRPC treated with MDT using SABR.

DESIGN, SETTING, AND PARTICIPANTS

Patients with oligoprogressive CRPC were retrospectively evaluated, and outcomes following MDT were reported. Outcomes were additionally compared with oligoprogressive CRPC treated with change in systemic therapy alone.

INTERVENTION

SABR to oligoprogressive lesions.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Outcomes of interest were time to prostate-specific antigen (PSA) failure, time to next intervention (TTNI), distant metastasis-free survival (DMFS), and overall survival. Survival analysis was performed using the Kaplan-Meier method, and univariable analysis and multivariable analysis (MVA) were performed.

RESULTS AND LIMITATIONS

A total of 68 patients were included. After MDT, median time to PSA recurrence, TTNI, and DMFS were 9.7, 15.6, and 10.8 months, respectively. A total of 112 lesions were treated, and the cumulative incidences of local failure at 12 and 24 months were 2.1% and 13.8%, respectively. Factors associated with the risk of local recurrence on univariable analysis were age (hazard ratio [HR] 1.07, p =  0.03) and Gleason grade group (HR 2.20, p =  0.07). Compared with change in systemic therapy alone (n = 52), MDT (n = 31) was associated with improved median time to PSA failure (9.7 vs 4.2 months, p =  0.066)), TTNI (14.9 vs 8.8 months, p =  0.025), and DMFS (12.7 vs 8.9 months, p = 0.045), and remained associated with improved outcomes on MVA.

CONCLUSIONS

In a retrospective cohort of oligoprogressive CRPC patients, MDT was associated with favorable outcomes and improved cancer control as compared with change in systemic treatment alone. Future prospective trials are needed to confirm these findings.

PATIENT SUMMARY

In this report, we retrospectively analyzed outcomes of patients with oligoprogressive castrate-resistant prostate cancer treated with radiation therapy to progressing lesions. Our results suggest that treatment of these lesions with radiation therapy can result in sustained periods of disease-free survival and might add benefit in addition to systemic therapy at the time of progression. These results need to be verified in a prospective trial to identify the optimal integration of radiation therapy into metastatic castrate-resistant prostate cancer.

Oligoprogressive Non-Small-Cell Lung Cancer under Treatment with PD-(L)1 Inhibitors

Oligoprogression (OPD) of non-small-cell lung cancer (NSCLC) occurs in approximately half of patients under targeted compounds (TKI) and facilitates use of regional therapies that can prolong survival. In order to characterize OPD in immunotherapy (IO)-treated NSCLC, we analyzed the failure pattern under PD-1/PD-L1 inhibitors (n = 297) or chemoimmunotherapy (n = 75). Under IO monotherapy, OPD was more frequent (20% vs. 10%, p < 0.05), occurred later (median 11 vs. 5 months, p < 0.01), affected fewer sites (mean 1.1 vs. 1.5, p < 0.05), and involved fewer lesions (1.4 vs. 2.3, p < 0.05) in the first compared to later lines. Lymph nodes (42%, mainly mediastinal) and the brain (39%) were mostly affected, followed by the lung (24%) and other organs. Compared to multifocal progression, OPD occurred later (11 vs. 4 months, p < 0.001) and was associated with longer survival (26 vs. 13 months, p < 0.001) and higher tumor PD-L1 expression (p < 0.001). Chemoimmunotherapy showed a similar incidence of OPD as IO monotherapy (13% vs. 11% at 2 years). Local treatments were applied regularly for brain but only in 50% for extracranial lesions. Thus, NSCLC oligoprogression is less common under IO than under TKI, but also favorable. Since its frequency drops later in the disease, regular restaging and multidisciplinary evaluation are essential in order to exploit the full therapeutic potential.

Analysis of Progression Patterns and Failure Sites of Patients With Metastatic Lung Adenocarcinoma With EGFR Mutations Receiving First-line Treatment of Tyrosine Kinase Inhibitors

BACKGROUND

Reliable prediction of progression patterns and failure sites for patients with stage IV lung adenocarcinoma is valuable for physicians to deliver personalized tyrosine kinase inhibitor (TKI) treatment.

PATIENTS AND METHODS

We retrospectively enrolled 266 patients who had stage IV lung adenocarcinoma and received first-line TKI treatment from 2013 to 2017 in Shanghai Chest Hospital. The clinical characteristics at initial diagnosis, progression patterns, and failure sites were analyzed with the attempt to identify some predictive factors for progression patterns and failure sites.

RESULTS

Among all patients, 62.4% developed systemic progression, and 37.6% developed oligoprogression. Both cohorts had a median progression-free survival (PFS) of 9 months. The percentage of patients who developed original and distant failure was 39.1% and 60.9%, respectively. Patients with oligometastasis at initial diagnosis were more prone to develop oligoprogression (odds ratio [OR], 4.370; 95% confidence interval [CI], 1.881-10.151; P = .001), whereas pulmonary metastasis was negatively correlated with oligoprogression (OR, 0.567; 95% CI, 0.330-0.974; P = .04). Both oligometastasis diagnosis (OR, 2.959; 95% CI, 1.347-6.500; P = .007) and the maximum diameter of the primary lung lesion (threshold 3.25 cm: OR, 3.646; 95% CI, 2.041-6.515; P = .0001) were strong predictive factors for original failures. Osseous metastasis at initial diagnosis might be an indication for distant failure (OR, 0.536; 95% CI, 0.316-0.909; P = .021).

CONCLUSION

Over one-half of patients with stage IV lung adenocarcinoma receiving first-line TKI treatment developed systemic progression and distant failure. Metastasis patterns at initial diagnosis was the most important predictive factor for progression patterns and failure sites. The maximum diameter of the primary lung lesion and evidence of osseous metastasis were also found to be significant indicative factors for failure sites.

Liquid biopsy, a paradigm shift in oncology: what interventional radiologists should know

The acquisition of adequate tumor sample is required to verify primary tumor type and specific biomarkers and to assess response to therapy. Historically, invasive surgical procedures were the standard methods to acquire tumor samples until advancements in imaging and minimally invasive equipment facilitated the paradigm shift image-guided biopsy. Image-guided biopsy has improved sampling yield and minimized risk to the patient; however, there are still limitations, such as its invasive nature and its consequent limitations to longitudinal tumor monitoring. The next paradigm shift in sampling technique will need to address these issues to provide a more reliable and less invasive technique. Recently, liquid biopsy (LB) has emerged as a non-invasive alternative to tissue sampling. This technique relies on direct sampling of blood or other bodily fluids in contact with the tumor in order to collect circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and circulating RNAs-in particular microRNA (miRNAs). Clinical applications of LB involve different steps of cancer patient management including screening, detection of disease recurrence, and evaluation of acquired resistance. With any paradigm shift, old techniques are often relegated to a secondary option. Although image-guided biopsies may appear as a passive spectator on the rapid advancement of LB, the two techniques may well be codependent. Interventional radiology may be integral to directly sample the liquid surrounding or draining from the tumor. In addition, LB may help to correctly select the patients for image-guided loco-regional treatments, to determine its treatment endpoint, and to early detect recurrence. KEY POINTS: • Liquid biopsy is a novel technology with potential high impact in the management of patients undergoing image-guided procedures. • Interventional radiology procedures may increase liquid biopsy sensitivity through direct fluid sampling. • Liquid biopsy techniques may provide a venue for improving patients' selection and enhance outcomes of interventional loco-regional therapies performed by interventional radiologists.

Stereotactic body radiotherapy (SBRT) for adrenal metastases of oligometastatic or oligoprogressive tumor patients

INTRODUCTION

Local ablative treatment strategies are frequently offered to patients diagnosed with oligometastatic disease. Stereotactic body radiotherapy (SBRT), as ablative treatment option, is well established for lung and liver metastases, whereas for isolated adrenal gland metastases the level of evidence is scarce.

MATERIAL AND METHODS

This single-institution analysis of oligometastatic or oligoprogressive disease was limited to patients who received SBRT to adrenal metastasis between 2012 and 2019. Patient, tumor, treatment characteristics, and dosimetric parameters were analyzed for evaluation of their effect on survival outcomes.

RESULTS

During the period of review 28 patients received ablative SBRT to their adrenal gland metastases. Most common primary tumors were non-small cell lung cancers (46%) with most patients diagnosed with a single adrenal gland metastasis (61%), which occurred after a median time of 14 months. SBRT was delivered to a median biological effective dose at α/β of 10 (BED₁₀) of 75 Gy (range: 58-151 Gy). Median gross tumor volume (GTV) and median planning target volume (PTV) were 42 and 111 mL, respectively. The homogeneity and conformity indices were 1.17 (range: 1.04-1.64) and 0.5 (range: 0.4.0.99), respectively, with the conformity index being affected by dose restrictions to organs at risk (OARs) in 50% of the patients. Overall response rate based on RECIST criteria was 86% (CR = 29%, PR = 57%) with 2-year local control (LC) of 84.8%, 2-year progression-free survival (PFS) of 26.3%, and 1-and 2-year overall survival (OS) of 46.6 and 32.0%, respectively. During follow up, only two local recurrences occurred. A trend for superior LC was seen if BED₁₀ was ≥75Gy (p = 0.101) or if the PTV was < 100 ml (p = 0.072). SBRT was tolerated well with only mild toxicity.

CONCLUSION

SBRT for adrenal metastases resulted in promising LC with low toxicity. Treatment response appeared to be superior, if SBRT was applied with higher BED. As the close proximity of OARs often limits the application of sufficiently high doses, further dose escalations strategies and techniques should be investigated in future.

Highlights on the Management of Oligometastatic Disease

Purpose: The understanding of oligometastatic disease (OMD) is rapidly evolving and with this comes the ability to utilize a number of modalities that excel in the localized control of disease. It has been identified that there are no clear guidelines based on high-level evidence to standardized approaches toward the management of OMD. These highlights have been developed to provide a road map for all health-care professionals who are involved in the management of OMD to support standardized patient care. Methods: The Saudi Lung Cancer Guidelines Committee is a part of the Saudi Lung Cancer Association which, in turn, is part of the Saudi Thoracic Society. Considering that lung cancer constitutes a major proportion of OMD prevalence, the committee took the initiative to develop national highlights to support the management of OMD within Saudi Arabia. The committee members are national clinical leaders who collaborated with international expertise to establish these highlights to serve as a general clinical pathway in the management of OMD. Results: Standardization of the indications to diagnose oligometastases and patient selection criteria including ineligibility criteria for treatment are the basis of the highlights. Treatment approaches including surgical and the variety of radiotherapeutical options are discussed in relation to specific oligometastatic sites. Acceptable measurements for response to treatment and the future for the treatment of OMD conclude the development of the highlights. Conclusion: These are the first national highlights addressing this important disease in oncology. The implementation of these highlights as guidelines requires a robust multidisciplinary team and access to specific technology and expertise. These highlights are based on the most recent findings within the literature but will require repeated review and updating due to this rapidly evolving field in disease management.

Stereotactic Body Radiation Therapy for Extracranial Oligometastatic Non-small-cell Lung Cancer: A Systematic Review

Stereotactic body radiation therapy (SBRT) has emerged as a treatment modality for selected patients with oligometastatic non-small-cell lung cancer (NSCLC). The objectives of this systematic review were to explore the benefits and risks of SBRT for extracranial oligometastatic NSCLC. The MEDLINE, Embase, PubMed, and CENTRAL databases were searched for relevant articles from January 1, 2000 to July 23, 2019. Fully published phase III or phase II trials of any sample size were included. Retrospective series published in manuscript form with at least 50 patients were also included. Four prospective phase II randomized trials (total, 188 participants), 4 prospective non-randomized studies (total, 140 participants), and eleven retrospective studies (total, 1288 participants) were included in this systematic review. A variety of dose fractionation schemes were used. The median overall survival (OS) ranged from 13.5 to 55 months. Progression-free survival (PFS) ranged from 4.4 to 14.7 months. Quality of life outcomes were reported in 2 studies. None of the studies reported symptom control outcomes. There are no fully completed phase III randomized trials that clarify the risks and benefits of SBRT for oligometastatic NSCLC. Higher PFS and OS with SBRT were reported in 4 phase II randomized studies. The results from mature phase III randomized data regarding whether SBRT for oligometastatic NSCLC benefits patients in terms of OS, PFS, quality of life, and symptom control are needed.