Reviewing RECIST in the Era of Prolonged and Targeted Therapy

The Role of Local Therapy for Oligo-Progressive Disease in Oncogene-Addicted Non-Small-Cell Lung Cancer

Purpose

We first described the role of local radiation therapy (LT) for oligoprogressive disease (OPD) on targeted therapy in 2012. Here, we present an updated and larger data set and extend the analysis beyond EGFR and ALK.

Methods

A retrospective review of patients with metastatic NSCLC harboring EGFR/BRAF V600E mutations, or ALK/ROS1/RET rearrangements, who had OPD on respective tyrosine-kinase inhibitor (TKI) and treated with LT was performed. OPD was defined as disease progression on therapy in ≤5 sites. PFS1 (progression-free survival 1) was defined as time from initiation of TKI-containing regimen to the first course of LT for OPD. Subsequent PFS times (eg, PFS2, PFS3) were defined as time from prior LT to subsequent LT, switch of systemic therapy, death, or loss to follow-up, whichever occurred first. Extended-PFS was defined as time from the first day of the first LT course to the day of change in systemic therapy, death, or loss to follow-up, whichever came first.

Results

Eighty-nine patients were identified. In 75.4% of the LT courses, a single lesion was treated. Median PFS1 was 10.2 months (95% CI, 8.7-13.1) and median Extended-PFS was 6.7 months (95% CI, 4.9-8.3). Extended-PFS was similar across different oncogenic drivers; 51.4% of patients who underwent LT to a single site had only 1 site on next disease progression.

Conclusions

LT is effective in prolonging treatment duration on TKI in oncogene-addicted NSCLC across multiple oncogenes.

Three scans are better than two for follow-up: An automatic method for finding missed and misidentified lesions in cross-sectional follow-up of oncology patients

PURPOSE

Missed and misidentified neoplastic lesions in longitudinal studies of oncology patients are pervasive and may affect the evaluation of the disease status. Two newly identified patterns of lesion changes, lone lesions and non-consecutive lesion changes, may help radiologists to detect these lesions. This study evaluated a new interpretation revision workflow of lesion annotations in three or more consecutive scans based on these suspicious patterns.

METHODS

The interpretation revision workflow was evaluated on manual and computed lesion annotations in longitudinal oncology patient studies. For the manual revision, a senior radiologist and a senior neurosurgeon (the readers) manually annotated the lesions in each scan and later revised their annotations to identify missed and misidentified lesions with the workflow using the automatically detected patterns. For the computerized revision, lesion annotations were first computed with a previously trained nnU-Net and were then automatically revised with an AI-based method that automates the workflow readers' decisions. The evaluation included 67 patient studies with 2295 metastatic lesions in lung (19 patients, 83 CT scans, 1178 lesions), liver (18 patients, 77 CECT scans, 800 lesions) and brain (30 patients, 102 T1W-Gad MRI scans, 317 lesions).

RESULTS

Revision of the manual lesion annotations revealed 120 missed lesions and 20 misidentified lesions in 31 out of 67 (46%) studies. The automatic revision reduced the number of computed missed lesions by 55 and computed misidentified lesions by 164 in 51 out of 67 (76%) studies.

CONCLUSION

Automatic analysis of three or more consecutive volumetric scans helps find missed and misidentified lesions and may improve the evaluation of temporal changes of oncological lesions.

Tumor marker-based RecistTM is superior to RECIST as criteria to predict the long-term benefits of targeted therapy in advanced non-small-cell lung cancer with driver gene mutations

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are standard first-line treatments for advanced non-small-cell lung cancer (NSCLC) with driver gene mutations. The Response Evaluation Criteria in Solid Tumors (RECIST) are limited in predicting long-term patient benefits. A tumour marker-based evaluation criteria, RecistTM, was used to investigate the potential for assessing targeted-therapy efficacy in lung cancer treatment.

METHODS

We retrospectively analysed patients with stage IIIA-IV NSCLC and driver gene mutations, whose baseline tumour marker levels exceeded the pre-treatment cut-off value three-fold and who received TKI-targeted therapy as a first-line treatment. We compared efficacy, progression-free survival (PFS), and overall survival (OS) between RecistTM and RECIST.

FINDINGS

The median PFS and OS differed significantly among treatment-response subgroups based on RecistTM but not RECIST. The predicted 1-, 2-, and 3-year disease-progression risk, according to area under the receiver operating characteristic curve, as well as the 1-, 3-, and 5-year mortality risk, differed significantly between RecistTM and RECIST. The median PFS and OS of tmCR according to RecistTM, was significantly longer than (CR+PR) according to RECIST. Imaging analysis revealed that the ΔPFS was 11.27 and 6.17 months in the intervention and non-intervention groups, respectively, suggesting that earlier intervention could extend patients' PFS.

INTERPRETATION

RecistTM can assess targeted-therapy efficacy in patients with advanced NSCLC and driver gene mutations, along with tumour marker abnormalities. RecistTM surpasses RECIST in predicting short- and long-term patient benefits, and allows the early identification of patients resistant to targeted drugs, enabling prompt intervention and extending the imaging-demonstrated time to progression.

Can we predict discordant RECIST 1.1 evaluations in double read clinical trials?

Background

In lung clinical trials with imaging, blinded independent central review with double reads is recommended to reduce evaluation bias and the Response Evaluation Criteria In Solid Tumor (RECIST) is still widely used. We retrospectively analyzed the inter-reader discrepancies rate over time, the risk factors for discrepancies related to baseline evaluations, and the potential of machine learning to predict inter-reader discrepancies.

Materials and methods

We retrospectively analyzed five BICR clinical trials for patients on immunotherapy or targeted therapy for lung cancer. Double reads of 1724 patients involving 17 radiologists were performed using RECIST 1.1. We evaluated the rate of discrepancies over time according to four endpoints: progressive disease declared (PDD), date of progressive disease (DOPD), best overall response (BOR), and date of the first response (DOFR). Risk factors associated with discrepancies were analyzed, two predictive models were evaluated.

Results

At the end of trials, the discrepancy rates between trials were not different. On average, the discrepancy rates were 21.0%, 41.0%, 28.8%, and 48.8% for PDD, DOPD, BOR, and DOFR, respectively. Over time, the discrepancy rate was higher for DOFR than DOPD, and the rates increased as the trial progressed, even after accrual was completed. It was rare for readers to not find any disease, for less than 7% of patients, at least one reader selected non-measurable disease only (NTL). Often the readers selected some of their target lesions (TLs) and NTLs in different organs, with ranges of 36.0-57.9% and 60.5-73.5% of patients, respectively. Rarely (4-8.1%) two readers selected all their TLs in different locations. Significant risk factors were different depending on the endpoint and the trial being considered. Prediction had a poor performance but the positive predictive value was higher than 80%. The best classification was obtained with BOR.

Conclusion

Predicting discordance rates necessitates having knowledge of patient accrual, patient survival, and the probability of discordances over time. In lung cancer trials, although risk factors for inter-reader discrepancies are known, they are weakly significant, the ability to predict discrepancies from baseline data is limited. To boost prediction accuracy, it would be necessary to enhance baseline-derived features or create new ones, considering other risk factors and looking into optimal reader associations.

Imaging Follow-Up of Nonsurgical Therapies for Lung Cancer: AJR Expert Panel Narrative Review

Lung cancer continues to be the most common cause of cancer-related death worldwide. In the past decade, with the implementation of lung cancer screening programs and advances in surgical and nonsurgical therapies, the survival of patients with lung cancer has increased, as has the number of imaging studies that these patients undergo. However, most patients with lung cancer do not undergo surgical re-section, because they have comorbid disease or lung cancer in an advanced stage at diagnosis. Nonsurgical therapies have continued to evolve with a growing range of systemic and targeted therapies, and there has been an associated evolution in the imaging findings encountered at follow-up examinations after such therapies (e.g., with respect to posttreatment changes, treatment complications, and recurrent tumor). This AJR Expert Panel Narrative Review describes the current status of nonsurgical therapies for lung cancer and their expected and unexpected imaging manifestations. The goal is to provide guidance to radiologists regarding imaging assessment after such therapies, focusing mainly on non-small cell lung cancer. Covered therapies include systemic therapy (conventional chemotherapy, targeted therapy, and immunotherapy), radiotherapy, and thermal ablation.

Clinical outcome assessment trends in clinical trials-Contrasting oncology and non-oncology trials

BACKGROUND

Clinical outcome assessments (COAs) are key to patient-centered evaluation of novel interventions and supportive care. COAs are particularly informative in oncology where a focus on how patients feel and function is paramount, but their incorporation in trial outcomes have lagged that of traditional survival and tumor responses. To understand the trends of COA use in oncology and the impact of landmark efforts to promote COA use, we computationally surveyed oncology clinical trials in ClinicalTrials.gov comparing them to the rest of the clinical research landscape.

METHODS

Oncology trials were identified using medical subject heading neoplasm terms. Trials were searched for COA instrument names obtained from PROQOLID. Regression analyses assessed chronological and design-related trends.

RESULTS

Eighteen percent of oncology interventional trials initiated 1985-2020 (N = 35,415) reported using one or more of 655 COA instruments. Eighty-four percent of the COA-using trials utilized patient-reported outcomes, with other COA categories used in 4-27% of these trials. Likelihood of COA use increased with progressing trial phase (OR = 1.30, p < 0.001), randomization (OR = 2.32, p < 0.001), use of data monitoring committees (OR = 1.26, p < 0.001), study of non-FDA-regulated interventions (OR = 1.23, p = 0.001), and in supportive care versus treatment-focused trials (OR = 2.94, p < 0.001). Twenty-six percent of non-oncology trials initiated 1985-2020 (N = 244,440) reported COA use; they had similar COA-use predictive factors as oncology trials. COA use increased linearly over time (R = 0.98, p < 0.001), with significant increases following several individual regulatory events.

CONCLUSION

While COA use across clinical research has increased over time, there remains a need to further promote COA use particularly in early phase and treatment-focused oncology trials.

Measurement Accuracy and Repeatability of RECIST-Defined Pulmonary Lesions and Lymph Nodes in Ultra-Low-Dose CT Based on Deep Learning Image Reconstruction

BACKGROUND

Deep learning image reconstruction (DLIR) improves image quality. We aimed to compare the measured diameter of pulmonary lesions and lymph nodes between DLIR-based ultra-low-dose CT (ULDCT) and contrast-enhanced CT.

METHODS

The consecutive adult patients with noncontrast chest ULDCT (0.07-0.14 mSv) and contrast-enhanced CT (2.38 mSv) were prospectively enrolled. Patients with poor image quality and body mass index ≥ 30 kg/m2 were excluded. The diameter of pulmonary target lesions and lymph nodes defined by Response Evaluation Criteria in Solid Tumors (RECIST) was measured. The measurement variability between ULDCT and enhanced CT was evaluated by Bland-Altman analysis.

RESULTS

The 141 enrolled patients (62 ± 12 years) had 89 RECIST-defined measurable pulmonary target lesions (including 30 malignant lesions, mainly adenocarcinomas) and 45 measurable mediastinal lymph nodes (12 malignant). The measurement variation of pulmonary lesions between high-strength DLIR (DLIR-H) images of ULDCT and contrast-enhanced CT was 2.2% (95% CI: 1.7% to 2.6%) and the variation of lymph nodes was 1.4% (1.0% to 1.9%).

CONCLUSIONS

The measured diameters of pulmonary lesions and lymph nodes in DLIR-H images of ULDCT are highly close to those of contrast-enhanced CT. DLIR-based ULDCT may facilitate evaluating target lesions with greatly reduced radiation exposure in tumor evaluation and lung cancer screening.

Clinical Efficacy of Laparoscopic Billroth II Subtotal Gastrectomy Plus Lienal Polypeptide Injection for Gastric Cancer

Objective

To evaluate the clinical efficacy of laparoscopic Billroth II subtotal gastrectomy plus lienal polypeptide injection for gastric cancer.

Methods

Between May 2018 and January 2021, 110 patients with gastric cancer treated in Jingzhou First People's Hospital were recruited and assigned via the random number table method to either an observation group or a control group, with 55 patients in each group. All patients received laparoscopic Billroth II subtotal gastrectomy, and the observation group additionally received lienal polypeptide injection. Outcome measures include surgical indexes, clinical efficacy, and adverse events.

Results

The patients in the observation group had significantly less intraoperative hemorrhage volume, smaller surgical wounds, shorter time lapse before passing gas and hospital stay, and longer operation time than those in the control group (P < 0.001). The observation group showed significantly higher efficacy than the control group (P=0.001). The observation group had a significantly lower incidence of toxic side effects and adverse events than the control group (P < 0.05). After treatment, the CD3+ and CD4+ levels were significantly elevated and the CD8+ level was decreased, with higher CD3+ and CD4+ levels and lower CD8+ levels in the observation group than in the control group (P < 0.05).

Conclusion

In the treatment of patients with gastric cancer, laparoscopic Billroth II subtotal gastrectomy plus lienal polypeptide injection features promising efficacy, improves the immune function of patients, effectively reduces the occurrence of toxic side effects and adverse reactions, with less trauma and rapid recovery, which shows good potential for use in clinical application.

Extending Our Reach: Expanding Enrollment in Brain Metastases and Primary Brain Tumor Clinical Trials

Despite the unmet need, clinical trial opportunities for primary and metastatic central nervous system cancers are limited and clinical trial enrollment is poor. Multiple stakeholders have launched efforts to improve the clinical trial landscape for patients with primary and metastatic central nervous system tumors, including work that promotes the inclusion of patients with brain tumors into clinical trials, re-examination of eligibility criteria, and careful consideration of trial design aspects that may uniquely impact the patients with this disease. Herein, we consider regulatory perspectives from the U.S. Food and Drug Administration and clinician-trialist perspectives from a neuro-oncologist and a medical oncologist.

The real-world clinical outcomes and treatment patterns of patients with unresectable locally advanced or metastatic soft tissue sarcoma treated with anlotinib in the post-ALTER0203 trial era

Background

The ALTER0203 clinical trial showed that anlotinib, a multitargeted tyrosine kinase inhibitor, had antitumor effects on advanced soft tissue sarcoma (STS) after the failure of standard chemotherapy. We aimed to evaluate the real‐world efficacy and explore prognostic factors and treatment patterns of anlotinib in patients with advanced STS.

Methods

We retrospectively analyzed the data of patients with unresectable locally advanced or metastatic STS who received at least one dose of anlotinib from June 2018 to March 2021. The survival data were analyzed using the Kaplan–Meier method and compared using the log‐rank test. The Cox proportional hazards model was performed for multivariate analysis.

Results

A total of 209 patients were included. The median age was 48 (range 11–85) years. The median follow‐up, progression‐free survival, and overall survival were 18.7 months, 6.1 months [95% confidence interval (CI): 4.9–7.2], and 16.4 months (95% CI: 13.6–19.1), respectively. The objective response rate was 13.4%. Nutritional status, Eastern Cooperative Oncology Group (ECOG) performance status, and anlotinib treatment patterns (combination therapy or switch maintenance therapy vs. monotherapy) were significantly associated with progression‐free survival. Besides, pathological grade, nutritional status, ECOG performance status, and anlotinib treatment patterns were predictive of overall survival. Due to anlotinib‐related toxicity, 31 (14.8%) patients, and 25 (12.0%) patients experienced dose reduction and treatment discontinuation, respectively.

Conclusion

These findings confirmed the efficacy of anlotinib in patients with advanced STS in a real‐world setting. The patterns of anlotinib treatment deserve further exploration.

Continuation of Lorlatinib in ALK-positive NSCLC Beyond Progressive Disease

INTRODUCTION

Lorlatinib, a potent, selective third-generation anaplastic lymphoma kinase tyrosine kinase inhibitor (ALK TKI), showed overall and intracranial anti-tumor activity in patients with ALK-positive non-small cell lung cancer (NSCLC).

METHODS

Retrospective analyses in the ongoing phase II trial (NCT01970865) investigated clinical benefit of continuing lorlatinib beyond progressive disease (LBPD). Patients with prior crizotinib as the only ALK TKI were Group A (n = 28); those with ≥1 prior second-generation ALK TKIs were Group B (n = 74). LBPD was defined as >3 weeks of lorlatinib treatment after investigator-assessed progressive disease. Only patients with a best overall response of complete or partial response or stable disease were included.

RESULTS

There were no major differences in baseline characteristics between groups. Median duration of treatment for LBPD patients was 32.4 months (Group A) and 16.4 months (Group B) versus 12.5 months (Group A) and 7.7 months (Group B) for non-LBPD patients. Median overall survival (OS) in Group A was not reached (NR) in LBPD patients versus 24.4 months (95% confidence interval [CI] 12.1-NR); Group B median was 26.5 months (95% CI 18.7-35.5) in LBPD patients versus 14.7 months (95% CI 9.3-38.5) in non-LBPD patients. Median OS post-progression for Groups A and B was NR (95% CI 21.4-NR) and 14.6 months (95% CI 11.2-19.2) in LBPD patients, and 8.0 months (95% CI 1.5-NR) versus 5.3 months (95% CI 2.8-14.3) in non-LBPD patients.

CONCLUSIONS

Continuing LBPD is a viable treatment option for select patients with ALK-positive NSCLC who progressed on lorlatinib.

Imaging evaluation of lung cancer treated with PD-1/PD-L1 inhibitors

Immunotherapy (PD-1/PD-L1 inhibitors) has attracted attention for lung cancer treatment and recasted the administration of immunotherapeutics to patients who have advanced/metastatic diseases. Whether in combination or as monotherapy, these medications have become common therapies for certain patients with lung cancer. Moreover, their usage is expected to expand widely in the future. This review aims to discuss the imaging evaluation of lung cancer response to PD-1/PD-L1 therapy with focus on new radiological criteria for immunotherapy response. Abnormal radiological responses (pseudoprogression, dissociative responses, and hyperprogression) and immune-related adverse events are also described.

Utilization of target lesion heterogeneity for treatment efficacy assessment in late stage lung cancer

RATIONALE

Recent studies have discovered several unique tumor response subgroups outside of response classification by Response Evaluation Criteria for Solid Tumors (RECIST), such as mixed response and oligometastasis. These subtypes have a distinctive property, lesion heterogeneity defined as diversity of tumor growth profiles in RECIST target lesions. Furthermore, many cancer clinical trials have been activated to evaluate various treatment options for heterogeneity-related subgroups (e.g., 29 trials so far listed in clinicaltrials.gov for cancer patients with oligometastasis). Some of the trials have shown survival benefit by tailored treatment strategies. This evidence presents the unmet need to incorporate lesion heterogeneity to improve RECIST response classification.

METHOD

An approach for Lesion Heterogeneity Classification (LeHeC) was developed using a contemporary statistical approach to assess target lesion variation, characterize patient treatment response, and translate informative evidence to improving treatment strategy. A mixed effect linear model was used to determine lesion heterogeneity. Further analysis was conducted to classify various types of lesion variation and incorporate with RECIST to enhance response classification. A study cohort of 110 target lesions from 36 lung cancer patients was used for evaluation.

RESULTS

Due to small sample size issue, the result was exploratory in nature. By analyzing RECIST target lesion data, the LeHeC approach detected a high prevalence (n = 21; 58%) of lesion heterogeneity. Subgroup classification revealed several informative distinct subsets in a descending order of lesion heterogeneity: mix of progression and regression (n = 7), mix of progression and stability (n = 9), mix of regression and stability (n = 5), and non-heterogeneity (n = 15). Evaluation for association of lesion heterogeneity and RECIST best response classification showed lesion heterogeneity commonly occurred in each response group (stable disease: 16/27; 59%; partial response: 3/5; 60%; progression disease: 2/4; 50%). Survival analysis showed a differential trend of overall survival between heterogeneity and non-heterogeneity in RECIST response groups.

CONCLUSION

This is the first study to evaluate lesion heterogeneity, an underappreciated metric, for RECIST application in oncology clinical trials. Results indicated lesion heterogeneity is not an uncommon event. The LeHeC approach could enhance RECIST response classification by utilizing granular lesion level discovery of heterogeneity.

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

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

Tyrosine Kinase Inhibitors and Hepatocellular Carcinoma

Sorafenib was the first tyrosine kinase inhibitor (TKI) that showed success in extending survival in patients with advanced hepatocellular carcinoma (HCC). In recent years, additional TKIs have been shown to improve survival and expanded the armamentarium for treating this malignancy. The current landscape includes other classes of drugs, such as immune checkpoint inhibitors and monoclonal antibodies. The challenge is now placed on how to best select, combine, and sequence drugs with the goal of improving efficacy and minimizing toxicities to deliver better outcomes for HCC patients.

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.

The Importance of Imaging Studies in the Assessment of Response to Immunotherapy in Lung Cancer

Immunotherapy (particularly immune checkpoint inhibitors) in the treatment of patients with lung cancer has aroused great interest in recent years, revolutionized the management of patients with locally advanced/metastatic disease, and given hope to both patients and treating physicians. These drugs, in combination or in monotherapy, have become the standard treatment for many patients with lung cancer, and their use is expected to increase significantly in the near future. In this article, we will review the growing importance of imaging techniques in the evaluation of therapeutic response to immunotherapy in lung cancer patients, with emphasis on the new specific radiological criteria on response to immunotherapy, atypical radiological responses (pseudoprogresion, dissociative responses, hyperprogresion), and the main radiological manifestations of adverse events associated with immunotherapy (sarcoid reactions, pulmonary toxicities, etc.). Pulmonologists must be familiar not only with atypical radiological responses to immunotherapy and their prognostic implications, but also with their effects and the new radiological criteria of response to assess treatment response. In this study, we will address key concepts such as "pseudoprogresion", "paradoxical response", "hyperprogresion", or "unconfirmed progression", and their significance in the management of patients with lung cancer treated with immunotherapy.

Brigatinib in Crizotinib-Refractory ALK+ NSCLC: 2-Year Follow-up on Systemic and Intracranial Outcomes in the Phase 2 ALTA Trial

INTRODUCTION

We report updated data from a phase 2 randomized study evaluating brigatinib in crizotinib-refractory anaplastic lymphoma kinase-positive NSCLC.

METHODS

Patients were randomized 1:1 to take either oral brigatinib 90 mg once daily (arm A) or 180 mg once daily with a 7-day lead-in at 90 mg (arm B), stratified by central nervous system (CNS) metastases and best response to crizotinib. The primary end point was investigator-assessed confirmed objective response rate per Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end points included independent review committee (IRC)-assessed progression-free survival (PFS), intracranial PFS (iPFS), and overall survival (OS). Exploratory analyses included CNS versus ex-CNS target lesion response and correlation of depth of response with PFS and OS.

RESULTS

Among 222 randomized patients (112 and 110 in arms A and B, respectively), 59 (27%) remained on brigatinib at analysis (median follow-up: 19.6 versus 24.3 months). At baseline, 71% and 67% had brain lesions among A and B arms, respectively. Investigator-assessed confirmed objective response rate was 46% versus 56%. Median IRC-assessed PFS was 9.2 months (95% confidence interval: 7.4-12.8) versus 16.7 months (11.6-21.4). Median OS was 29.5 months (18.2-not reached) versus 34.1 months (27.7-not reached). IRC-confirmed intracranial objective response rate in patients with measurable baseline brain lesions was 50% (13 of 26) versus 67% (12 of 18); median duration of intracranial response was 9.4 versus 16.6 months. IRC-assessed iPFS was 12.8 versus 18.4 months. Across arms, median IRC-assessed PFS was 1.9, 5.5, 11.1, 16.7, and 15.6 months for patients with no, 1%-25%, 26%-50%, 51%-75%, and 76%-100% target lesion shrinkage, respectively. No new safety findings were observed with longer follow-up.

CONCLUSIONS

Brigatinib (180 mg once daily with lead-in) continues to demonstrate robust PFS, long iPFS and duration of intracranial response, and high intracranial objective response rate in crizotinib-refractory patients. Depth of response may be an important end point to capture in future targeted therapy trials.

Management of one patient with oligoprogressive thyroid cancer during treatment with lenvatinib

Recent thyroid cancer guidelines found it reasonable to use local therapies during treatment with tyrosine kinase inhibitors (TKIs) in selected patients with oligoprogressive disease, namely, in the presence of a single progressing lesion in an otherwise TKI-responsive metastatic cancer. However, there is a lack of experience in the management of oligoprogressive thyroid cancers. This report illustrates the case of one patient with oligoprogressive thyroid cancer during therapy with lenvatinib. We found that the application of local ablative therapy in oligoprogressive disease prolonged the progression-free survival and thus extended the time to therapy interruption. However, the optimal care for TKI-treated oligoprogressive cancers remains unclear and needs to be investigated in prospective trials.

Local ablative therapy of oligoprogressive TKI-treated thyroid cancer

Metastatic cancer patients generally respond well to treatment with tyrosine kinase inhibitors (TKIs). However, TKI resistance occurs in almost all cases and often leads to a change in treatment. Recent guidelines, including thyroid cancer, raised the possibility of locally treating TKI-resistant oligoprogressive disease, i.e., one or a few progressing lesions in an otherwise treatment-responsive metastatic cancer, thereby obviating the need to change the ongoing TKI. To determine the benefits of this intervention, we reviewed studies on the use of LAT for TKI-treated oligoprogressive cancers. We found that in non-small cell lung cancer at least, LAT prolongs disease control and the duration of exposure to a TKI irrespective of the LAT used. Moreover, we reviewed the local ablative therapies (LATs) that are feasible for the local control of oligoprogressive thyroid cancer. Lastly, we report two illustrative cases of patients with oligoprogressive thyroid cancer treated with two different LATs while on therapy with TKIs. Both LATs extended the duration of disease control and the time of exposure to the ongoing TKI, thereby indicating that LAT is a favorable option for TKI-treated oligoprogressive thyroid cancer. Prospective randomized studies are needed to verify the benefit of LATs in terms of progression-free and overall survival in this increasingly frequent clinical setting.

Prognostic Impact of Longitudinal Monitoring of Radiomic Features in Patients with Advanced Non-Small Cell Lung Cancer

Tumor growth dynamics vary substantially in non-small cell lung cancer (NSCLC). We aimed to develop biomarkers reflecting longitudinal change of radiomic features in NSCLC and evaluate their prognostic power. Fifty-three patients with advanced NSCLC were included. Three primary variables reflecting patterns of longitudinal change were extracted: area under the curve of longitudinal change (AUC1), beta value reflecting slope over time, and AUC2, a value obtained by considering the slope and area over the longitudinal change of features. We constructed models for predicting survival with multivariate cox regression, and identified the performance of these models. AUC2 exhibited an excellent correlation between patterns of longitudinal volume change and a significant difference in overall survival time. Multivariate regression analysis based on cut-off values of radiomic features extracted from baseline CT and AUC2 showed that kurtosis of positive pixel values and surface area from baseline CT, AUC2 of density, skewness of positive pixel values, and entropy at inner portion were associated with overall survival. For the prediction model, the areas under the receiver operating characteristic curve (AUROC) were 0.948 and 0.862 at 1 and 3 years of follow-up, respectively. Longitudinal change of radiomic tumor features may serve as prognostic biomarkers in patients with advanced NSCLC.

The Dandelion Dilemma Revisited for Oligoprogression: Treat the Whole Lawn or Weed Selectively?

Oligoprogressive disease is a relatively new clinical concept describing progression at only a few sites of metastasis in patients with otherwise controlled widespread disease. In the era of well-tolerated targeted treatments, resistance inevitably occurs and overcoming this is a challenge. Local ablative therapy for oligoprogressive disease may allow the continuation of systemic treatments by overcoming the few sub-clones that have developed resistance. Stereotactic body radiotherapy is now frequently used in treating oligometastatic disease using ablative doses with minimally invasive techniques and acceptable toxicity. We discuss the current retrospective clinical evidence base supporting the use of local ablative therapy for oligoprogression in metastatic patients on targeted treatments within multiple tumour sites. As there is currently a lack of published prospective data available, the best management for these patients remains unclear. We discuss current trials in recruitment and the potential advancements in treating this group of patients with stereotactic radiotherapy.