Pulmonary metastasis of head and neck cancer: surgical removal outcomes from a tertiary care center

Approaches to the Management of Metastatic Adenoid Cystic Carcinoma

High rates of recurrence and distant metastasis are a foremost challenge in the management of adenoid cystic carcinoma (ACC), occurring in approximately 40% of all ACC patients. Despite the morbidity and mortality resulting from recurrent/metastatic (R/M) disease, there are no FDA-approved systemic agents for these patients. In this review, we summarize pertinent ACC pathophysiology and its implications for different systemic treatment regimens in R/M ACC. We review the evidence for the most widely used systemic agents - cytotoxic chemotherapy and tyrosine kinase inhibitors (TKIs) targeting VEGFR - in addition to immune checkpoint inhibitors and non-TKI biologic agents. Exciting emerging targets for R/M ACC, including inhibitors of Notch signaling, stemness, PRMT5, and Axl, are also discussed. Lastly, we review local therapies for small-volume lung disease in patients with oligometastatic ACC, specifically pulmonary metastasectomy and stereotactic body radiation therapy (SBRT). Future development of targeted molecular agents which exploit the underlying biology of this disease may yield novel therapeutic options to improve clinical outcomes in patients with R/M ACC.

Patients with Pulmonary Metastases from Head and Neck Cancer Benefit from Pulmonary Metastasectomy, A Systematic Review

Background and Objectives: The incidence of distant metastases in patients with head and neck cancer (HNC) is approximately 10%. Pulmonary metastases are the most frequent distant location, with an incidence of 70-85%. The standard treatment options are chemo-, immuno- and radiotherapy. Despite a benefit for long-term survival for patients with isolated pulmonary metastases, pulmonary metastasectomy (PM) is not the treatment of choice. Furthermore, many otorhinolaryngologists are not sufficiently familiar with the concept of PM. This work reviews the recent studies of pulmonary metastatic HNC and the results after pulmonary metastasectomy. Materials and Methods: PubMed, Medline, Embase, and the Cochrane library were checked for the case series' of patients undergoing metastasectomy with pulmonary metastases published since 1 January 2000. Results: We included the data of 15 studies of patients undergoing PM. The 5-year survival rates varied from 21% to 59%, with median survival from 10 to 77 months after PM. We could not identify one specific prognostic factor for long-term survival after surgery. However, at least most studies stated that PM should be planned if a complete (R0) resection is possible. Conclusions: PM showed reliable results and is supposedly the treatment of choice for patients with isolated pulmonary metastases. Patients not suitable for surgery may benefit from other non-surgical therapy. Every HNC patient with pulmonary metastases should be discussed in the multidisciplinary tumor board to optimize the therapy and the outcome.

Tumor-Derived Exosomes Modulate Primary Site Tumor Metastasis

Tumor-derived exosomes (TDEs) are actively produced and released by tumor cells and carry messages from tumor cells to healthy cells or abnormal cells, and they participate in tumor metastasis. In this review, we explore the underlying mechanism of action of TDEs in tumor metastasis. TDEs transport tumor-derived proteins and non-coding RNA to tumor cells and promote migration. Transport to normal cells, such as vascular endothelial cells and immune cells, promotes angiogenesis, inhibits immune cell activation, and improves chances of tumor implantation. Thus, TDEs contribute to tumor metastasis. We summarize the function of TDEs and their components in tumor metastasis and illuminate shortcomings for advancing research on TDEs in tumor metastasis.

Survival and Prognostic Analysis after Pulmonary Metastasectomy for Head and Neck Cancer

BACKGROUND

 There is no consensus on the value of pulmonary metastasectomy (PM) for head and neck cancer (HNC). The aim of our single-institution study was to evaluate outcomes and to examine factors influencing 5-year survival of patients undergoing resections for HNC lung metastases.

METHODS

 All HNC patients undergoing curative-intent PM between January 2008 and December 2018 were retrospectively analyzed. The impact of factors related to primary tumor, metastases, and associated therapy on patient survival was evaluated using the univariable Cox proportional hazard model. Cutoff values of continuous variables were determined by a receiver operating characteristic analysis.

RESULTS

 In total, 44 patients (32 males and 12 females, with a median age of 65 years) underwent PM for metastatic HNC. There was one perioperative death, and major complications occurred in 2 (4.5%) patients. The median interval between the treatment of primary tumor and PM was 19.4 months (range: 0-151 months). Median size of the largest resected pulmonary lesion was 1.3 cm (range: 0.3-6.9 cm). Mean follow-up was 21 months (range: 0-123 months), and 5-year overall survival (OS) rate after the first PM was 41%. Resection was complete (R0) in all patients. Larger size of pulmonary metastasis (≥1.4 cm; hazard ratio: 4.49; 95% confidence interval: 1.79-11.27) was a significantly negative prognostic factor.

CONCLUSION

 Despite the lack of randomized controlled trials, PM for HNC is a reasonable therapeutic option with favorable survival in a selected population. In patients with larger pulmonary lesions, shorter OS after PM is to be expected.