Stereotactic body radiotherapy extends the clinical benefit of PD-1 inhibitors in refractory recurrent/metastatic nasopharyngeal carcinoma

International Recommendations on Postoperative Management for Potentially Resectable Locally Recurrent Nasopharyngeal Carcinoma

Locally recurrent nasopharyngeal carcinoma (NPC) presents substantial challenges in clinical management. Although postoperative re-irradiation (re-RT) has been acknowledged as a potential treatment option, standardized guidelines and consensus regarding the use of re-RT in this context are lacking. This article provides a comprehensive review and summary of international recommendations on postoperative management for potentially resectable locally recurrent NPC, with a special focus on postoperative re-RT. A thorough search was conducted to identify relevant studies on postoperative re-RT for locally recurrent NPC. Controversial issues, including resectability criteria, margin assessment, indications for postoperative re-RT, and the optimal dose and method of re-RT, were addressed through a Delphi consensus process. The consensus recommendations emphasize the need for a clearer and broader definition of resectability, highlighting the importance of achieving clear surgical margins, preferably through an en bloc approach with frozen section margin assessment. Furthermore, these guidelines suggest considering re-RT for patients with positive or close margins. Optimal postoperative re-RT doses typically range around 60 Gy, and hyperfractionation has shown promise in reducing toxicity. These guidelines aim to assist clinicians in making evidence-based decisions and improving patient outcomes in the management of potentially resectable locally recurrent NPC. By addressing key areas of controversy and providing recommendations on resectability, margin assessment, and re-RT parameters, these guidelines serve as a valuable resource for clinical experts involved in the treatment of locally recurrent NPC.

Immunotherapy for recurrent or metastatic nasopharyngeal carcinoma

Immunotherapy, particularly immune checkpoint inhibitors (ICIs), such as anti-programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) therapy, has emerged as a pivotal treatment modality for solid tumors, including recurrent or metastatic nasopharyngeal carcinoma (R/M-NPC). Despite the advancements in the utilization of ICIs, there is still room for further improving patient outcomes. Another promising approach to immunotherapy for R/M-NPC involves adoptive cell therapy (ACT), which aims to stimulate systemic anti-tumor immunity. However, individual agent therapies targeting dendritic cells (DCs) appear to still be in the clinical trial phase. This current review underscores the potential of immunotherapy as a valuable adjunct to the treatment paradigm for R/M-NPC patients. Further research is warranted to enhance the efficacy of immunotherapy through the implementation of strategies such as combination therapies and overcoming immune suppression. Additionally, the development of a biomarker-based scoring system is essential for identifying suitable candidates for precision immunotherapy.

A prospective, single-arm trial of PD-1 inhibitors plus chemoradiotherapy for solitary metachronous metastasis nasopharyngeal carcinoma

PURPOSE

Initial treatment for Recurrent/Metastatic Nasopharyngeal Carcinoma (R/M NPC) often involves Gemcitabine plus cisplatin with or without PD-1 inhibitors. However, PD-1 inhibitors' effectiveness varies, prompting for better treatments. This study explores effect and safety of combining PD-1 inhibitors with chemoradiotherapy for oligometastatic NPC patients.

METHODS

Oligometastatic NPC patients underwent radical treatment with PD-1 inhibitors and chemotherapy, followed by concurrent PD-1 inhibitors and chemoradiotherapy, and then maintenance PD-1 inhibitors. Objective response rate (ORR) and disease control rate (DCR) were calculated by irRECIST-1.1, and CTCAE-4.0 was used to evaluate the toxicity.

RESULTS

The study enrolled 47 patients with a median age of 46. The median follow-up lasted 16.5 months, with metastatic lesions receiving a median radiation dose of 45 Gy. The median courses of PD-1 inhibitors and chemotherapy were 9.5 and 5 respectively. The metastasis sites included lung (40.8 %), liver (21.1 %), mediastinal lymph node (7.9 %), abdominal lymph nodes (3.9 %), bone (21.1 %), adrenal gland (3.9 %), and brain (1.3 %). ORR and DCR were 85.1 % and 100 % at 3 months after radiotherapy. The median survival was not reached yet, and 1 and 2-year OS rates were 93.1 % and 78.4 %. The median PFS was 18 months, with 1 and 2-year PFS rates of 70.2 % and 47.7 % respectively. PD-L1 expression showed a positive correlation for PFS. Twenty-five patients experienced grade 3 or 4 adverse events (AE) that were possibly related to chemotherapy. No grade 5 AE was observed.

CONCLUSIONS

The synergy of concurrent PD-1 inhibitors and chemoradiotherapy shows promising efficacy and an acceptable toxicity for oligometastasis NPC patients.

Long-term outcomes of metastasis-directed stereotactic body radiation therapy in metastatic nasopharyngeal carcinoma

BACKGROUND

The study aims to evaluate the outcomes of metastasis-directed stereotactic body radiation therapy (SBRT) in metastatic nasopharyngeal carcinoma (mNPC).

METHODS

We reviewed all SBRT conducted in patients with mNPC in our institution between 2013 and 2022. Systemic therapy was performed with chemotherapy with or without anti-programmed death-1 (PD-1) therapy. Local treatment delivered with ablative purpose in stereotactic setting with dose/fraction ≥5 Gy was evaluated. Kaplan-Meier analyses were used to determine the rates of local control (LC), progression-free survival (PFS), and overall survival (OS). Univariate and multivariate analyses were performed by Cox regression.

RESULTS

A total of 54 patients with 76 metastatic sites receiving SBRT were analyzed. Median follow-up was 49 months. The 3-year LC, PFS, and OS rates were 89.1%, 29.4%, and 57.9%, respectively. Adding a PD-1 inhibitor to SBRT tended to prolong median OS (50.1 vs. 32.2 months, p = 0.068). Patients receiving a biological effective dose (BED, α/β = 10) ≥ 80 Gy had a significantly longer median OS compared to those who received a lower dose (not reached vs. 29.5 months, p = 0.004). Patients with oligometastases (1-5 metastases) had a better median OS (not reached vs. 29.5 months, p < 0.001) and PFS (34.3 vs. 4.6 months, p < 0.001). Pretreatment EBV-DNA and maintenance therapy were also significant predictors for OS.

CONCLUSIONS

Metastatic NPC patients could benefit from metastases-directed SBRT in combination with systemic therapy.

Re-irradiation for head and neck cancer: outcome and toxicity analysis using a prospective single institution database

Purpose

Re-irradiation (re-RT) in head and neck cancer is challenging. This study prospectively explored the feasibility of re-RT in patients with loco-regionally recurrent or second primary head and neck cancer (LRR/SP HNC).

Methods

From 2004 to 2021, 61 LRR/SP HNC patients were treated with re-RT, defined as having a second course of RT with curative intent resulting in a cumulative dose of ≥100 Gy in an overlapping volume. Postoperative or definitive dynamic intensity-modulated and/or volumetric modulated re-RT was administered using twice daily hyperfractionation to 60 Gy combined with cisplatin or carboplatin/5-fluorouracil. Overall survival (OS), progression-free survival (PFS), locoregional control (LRC) and distant metastasis control (DMC) were analyzed and prognostic factors evaluated. Toxicity was prospectively recorded and graded.

Results

The median follow-up was 9.8 months. In 41 patients (67.1%), complete administration of the intended treatment was not feasible. In 9 patients (15%) re-RT was interrupted prematurely and in other 9, the complete re-RT dose was lower than 60 Gy, and 37 patients (61%) could not receive or complete chemotherapy. Two-year OS, PFS and LRC rates were 19%, 18% and 30%, respectively. 20 patients (33%) received the complete intended treatment, and 1- and 2-year OS rates were 70% and 47%, respectively. Charlson comorbidity index was an important predictor for treatment completion. Multivariate analysis revealed recurrent N stage 0-1, age, chemotherapy administration and re-RT dose of 60 Gy as prognostic factors for clinical outcomes. No grade 5 re-RT-related toxicity was observed. The most common new grade ≥3 acute toxicities were dysphagia (52%) and mucositis (46%). Late toxicity included grade ≥3 dysphagia in 5% and osteoradionecrosis in 10% of evaluable patients, respectively. 6 patients (10%) were alive after 9 years without progression and no late toxicity grade ≥3, except for 2 patients presenting with osteoradionecrosis.

Conclusion

Hyperfractionated re-RT with 60 Gy combined with platinum-based chemotherapy was a curative treatment option with acceptable toxicity in LRR/SP patients. Patients with higher comorbidity had a higher probability of failing to receive and complete the intended therapy. Consequently, they derived unsatisfactory benefits from re-RT, highlighting the importance of patient selection.

Roles of tumor-associated macrophages in anti-PD-1/PD-L1 immunotherapy for solid cancers

In recent years, tumor immunotherapy has made significant progress. However, tumor immunotherapy, particularly immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), benefits only a tiny proportion of patients in solid cancers. The tumor microenvironment (TME) acts a significant role in tumor immunotherapy. Studies reported that tumor-associated macrophages (TAMs), as one of the main components of TME, seriously affected the therapeutic effect of PD-1/PD-L1 inhibitors. In this review, we analyzed TAMs from epigenetic and single-cell perspectives and introduced the role and mechanisms of TAMs in anti-programmed death protein 1(anti-PD-1) therapy. In addition, we summarized combination regimens that enhance the efficacy of tumor PD-1/PD-L1 inhibitors and elaborated on the role of the TAMs in different solid cancers. Eventually, the clinical value of TAMs by influencing the therapeutic effect of tumor PD-1/PD-L1 inhibitors was discussed. These above are beneficial to elucidate poor therapeutic effect of PD-1/PD-L1 inhibitors in solid tumors from the point of view of TAMs and explore the strategies to improve its objective remission rate of solid cancers.

Efficacy and safety of PD1/PDL1 inhibitors combined with radiotherapy and anti-angiogenic therapy for solid tumors: A systematic review and meta-analysis

BACKGROUND

The triple combination of programmed cell death 1 (PD1)/programmed cell death ligand 1 (PDL1) inhibitors, radiotherapy (RT), and anti-angiogenesis agents has been widely used in the treatment of solid tumors and has shown positive efficacy. We conducted a meta-analysis to evaluate the efficacy and safety of PD1/PDL1 inhibitors combined with anti-angiogenic agents and RT for the treatment of solid cancers.

METHODS

A systematic search of PubMed, Embase, Cochrane Library, and Web of Science databases was conducted from inception to October 31, 2022. Studies involving patients with solid cancers who received PD1/PDL1 inhibitors combined with RT and anti-angiogenic agents treatment that reported overall response rate, complete remission rate, disease control rate, and adverse events (AEs) were included. A random-effects or fixed-effects model was used for the pooled rates, and 95% confidence intervals (CIs) were determined for all outcomes. The quality of the included literature was assessed using the methodological index for nonrandomized studies critical appraisal checklist. Egger test was used to assess the publication bias in the included studies.

RESULTS

Ten studies (4 nonrandomized controlled trials and 6 single-arm trials), including 365 patients, were identified and included in the meta-analysis. The pooled overall response rate after treatment with PD1/PDL1 inhibitors combined with RT and anti-angiogenic agents was 59% (95% CI: 48-70%), whereas the disease control rate and complete remission rate were 92% (95% CI: 81-103%) and 48% (95% CI: 35-61%), respectively. Moreover, the meta-analysis showed that compared with triple-regimen, monotherapy or dual-combination treatment did not improve overall survival (hazard ratio = 0.499, 95% CI: 0.399-0.734) and progression-free survival (hazard ratio = 0.522, 95% CI: 0.352-0.774). The pooled rate of grade 3 to 4 AEs was 26.9% (95% CI: 7.8%-45.9), and the common AEs to triple therapy included leukopenia (25%), thrombocytopenia (23.8%), fatigue (23.2%), gastrointestinal discomfort (22%), increased alanine aminotransferase (22%), and neutropenia (21.4%).

CONCLUSION

In the treatment of solid tumors, PD1/PDL1 inhibitors combined with RT and anti-angiogenic drugs achieved a positive response and better survival benefits than monotherapy or dual therapy. In addition, combination therapy is tolerable and safe.

REGISTRATION

PROSPERO ID: CRD42022371433.

Are PD-1 inhibitors effective for recurrent/metastatic nasopharyngeal carcinoma? Meta-analysis and systematic review

Objective: For metastatic/recurrent nasopharyngeal carcinoma (NPC) patients, a programmed cell death protein 1 (PD-1) is a controversial option. This meta-analysis aimed to investigate the efficacy and safety of PD-1 inhibitors in patients with metastatic/recurrent NPC. Methods: Electronic databases such as PubMed, Embase, Cochrane library, and Web of Science were manually searched until 1 July 2022, and Stata 15.0 was used to analyze the data. Result: A total of 10 studies were included, of which three were randomized controlled trials with data, and seven were single-arm studies. For randomized controlled trial (RCT) study, ORR [OR = 1.11, 95% CI (.49, 2.52); p = .812], OS [1-year OR = 1.26, 95% CI (.76, 2.08); p = .367], [2-year OR = 1.04, 95% CI (.39, 2.71); p = .928] in patients with metastatic/recurrent NPC were consistent with PD-1 inhibitor therapy and conventional chemotherapy. However, PD-1 inhibitor had higher 1-year PFS than conventional chemotherapy [OR = 2.16, 95% CI (1.26, 3.70); p = .005]. For single-arm studies, after PD-1 inhibitor therapy, the ORR of patients with recurrent/metastatic NPC reached [ES = 37%, 95 CI (17%-56%)], 1-year OS [ES = 61%, 95% CI (46%-76%)], 2-year [ES = 16%, 95% CI (6%-26%)], and 1-year PFS [ES = 16%,95% CI (12%-20%)]. Conclusion: The efficacy of PD-1 inhibitor monotherapy in patients with metastatic/recurrent nasopharyngeal carcinoma was not significantly different from that of conventional chemotherapy; however, due to the limitations of the included studies, further phase III RCTs are required to corroborate our conclusion. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022342400; Identifier: CRD42022342400.