Response to crizotinib observed in metastatic mediastinum lymph node from a non-small cell lung cancer patient harboring EZR-ROS1 fusion

CT-guided iodine-125 brachytherapy is an effective palliative treatment for the right lower paratracheal lymph nodes metastasis previously treatment failure

PURPOSE

This study aimed to evaluate the effectiveness and safety of iodine-125 brachytherapy as a treatment for right lower paratracheal lymph node metastasis following unsuccessful prior therapies.

METHODS

A retrospective review of patients who underwent iodine-125 brachytherapy for right lower paratracheal lymph node metastasis was conducted. The study included 24 patients who met the predefined criteria. Iodine-125 seeds were implanted under CT guidance, and treatment planning was performed using a treatment planning system. The primary endpoint was the objective response rate (ORR), while overall survival (OS) and complications were secondary endpoints.

RESULTS

The ORR was 87.5%, with 4 patients achieving complete response (CR) and 17 patients achieving partial response (PR). The mean diameter of metastatic lymph nodes significantly reduced from 40.21 ± 6.66 mm before treatment to 12.25 ± 9.27 mm at the last follow-up (p < 0.001). The median OS was 14.70 months, with 1-year and 2-year survival rates of 78.9% and 20.9%, respectively. Clinical symptoms significantly improved, as indicated by increased Karnofsky Performance Score (KPS) scores. Complications were manageable, with no procedure-related deaths.

CONCLUSION

Iodine-125 brachytherapy demonstrated promising efficacy and safety as an alternative treatment for right lower paratracheal lymph node metastasis after unsuccessful prior therapies.

Interstitial Deletions Generating Fusion Genes

A fusion gene is the physical juxtaposition of two different genes resulting in a structure consisting of the head of one gene and the tail of the other. Gene fusion is often a primary neoplasia-inducing event in leukemias, lymphomas, solid malignancies as well as benign tumors. Knowledge about fusion genes is crucial not only for our understanding of tumorigenesis, but also for the diagnosis, prognostication, and treatment of cancer. Balanced chromosomal rearrangements, in particular translocations and inversions, are the most frequent genetic events leading to the generation of fusion genes. In the present review, we summarize the existing knowledge on chromosome deletions as a mechanism for fusion gene formation. Such deletions are mostly submicroscopic and, hence, not detected by cytogenetic analyses but by array comparative genome hybridization (aCGH) and/or high throughput sequencing (HTS). They are found across the genome in a variety of neoplasias. As tumors are increasingly analyzed using aCGH and HTS, it is likely that more interstitial deletions giving rise to fusion genes will be found, significantly impacting our understanding and treatment of cancer.

CT-guided iodine-125 brachytherapy as salvage therapy for recurrent mediastinal lymph node metastasis

Background

The treatment of recurrent mediastinal lymph node metastasis (MLNMs) is challenging. We conducted this study to evaluate the effectiveness and safety of computed tomography (CT)‐guided percutaneous iodine‐125 brachytherapy for MLNMs.

Methods

We retrospectively analyzed 33 patients with recurrent MLNMs treated with CT‐guided interstitial implantation of iodine‐125 seeds. Regular contrast‐enhanced CT was conducted to evaluate the tumor response. Follow‐up survival, quality of life, and adverse events were analyzed.

Results

The number of implanted seeds was 16–85 (median, 40). The matched peripheral dose was 110–160 Gy. The patients were followed up for 5–24 months (median, 14 months). At the last follow‐up or death, complete response to therapy was achieved in 11 patients (33.3%) and partial response in 18 patients (54.5%). The median survival time of this cohort was 15.2 months (95% confidence interval [CI], 9.9–20.5 months); the estimated one‐ and two‐year survival rates were 68.6% and 31.1%, respectively. The Karnofsky performance score increased significantly after the procedure (p = 0.007). Pneumothorax with pulmonary compression of 30% to 40% occurred in five (15.2%) patients and was cured after drainage. No severe complications occurred.

Conclusions

CT‐guided iodine‐125 brachytherapy provided a safe and effective choice for recurrent mediastinal lymph node metastasis with significant local therapeutic effects and minor complications, especially for patients who were not eligible for surgical resection and had failed to benefit from systemic therapy.

Efficacy of crizotinib and pemetrexed-based chemotherapy in Chinese NSCLC patients with ROS1 rearrangement

Background

ROS1 rearrangement is a novel molecular subgroup of non-small-cell lung cancer (NSCLC). This study aimed to investigate the efficacy of crizotinib and pemetrexed-based chemotherapy in Chinese NSCLC patients with ROS1 rearrangement.

Results

A total of 2309 patients received ROS1 fusion detection and 51(2.2%) patients had ROS1 rearrangement. There was no significant difference between ROS1 fusion-positive and fusion-negative cohorts in demographic data. For the ROS1 fusion-positive patients, crizotinb-treated group had a higher overall response rate (ORR, 80.0%), disease control rate (DCR, 90.0%) and longer progression-free survival (PFS, 294 days) compared with the rates in pemetrexed-treated group (ORR, 40.8%; DCR, 71.4%; PFS, 179 days) and non-pemetrexed-treated group (ORR, 25.0%; DCR, 47.7%; PFS, 110 days). Besides, ORR, DCR and PFS were similar in three major ROS1 fusion partners. For the first-line treatment, patients received pemetrexed had a significant longer PFS than those received non-pemetrexed chemotherapy (209 vs. 146 days, P = 0.0107). In pemetrexed-treated cohorts, ROS1-positive patients with low TS expression had a statistically significant longer PFS than those with high TS expression (184 vs. 110 days, P = 0.0105).

Materials and methods

We retrospectively identified patients with NSCLC who were screened for ROS1 fusion using multiplex reverse transcription-polymerase chain reaction (RT-PCR) from October 2013 to February 2016. The thymidylate synthase (TS) mRNA levels were tested using quantitative real-time RT-PCR.

Conclusions

Crizotinib was also highly active at treating Chinese NSCLC patients with ROS1 rearrangement. TS expression could predict the efficacy of pemetrexed-based therapy in ROS1 fusion-positive patients.