Humanitarian Maxillofacial Mission's Success Requires Experienced Surgeons, Careful Planning, and Meeting With the Local's Care Needs.

PURPOSE: Meeting with local needs of low- and middle-income countries during maxillofacial humanitarian mission is not easy. This article aimed to report on 5 years of experience in humanitarian maxillofacial surgery missions. In addition, several key points for best practices and meeting the medical needs of local populations are discussed. METHODS: In this retrospective case series, all medical charts of patients managed during humanitarian maxillofacial surgery missions organized within the department of maxillofacial surgery of Le Dantec Hospital (Senegal) were analyzed. Disease characteristics, treatments modality, and outcomes were reviewed. Moreover, missions planning and costs were studied. RESULTS: Between 2015 and 2018, 5 humanitarian missions were organized totalizing 177 patients, one-third of which were treated surgically. Tumors (35%) and sequelae from previous surgeries, cancrum oris or trauma (24%) were the most frequently treated disorders. Most patients were treated with free flap reconstructions (35%). Postoperative complications were observed for only 3 patients (5%). With a median follow-up of 13 months, no sequelae requiring specific treatment were observed. The estimated total cost for each mission was $39,000. CONCLUSION: In order to benefit both the locals and the volunteers, humanitarian maxillofacial missions should be carefully planned and volunteers appropriately prepared. Other keys to the success of such missions are setting up training and support programs, reflecting upon ethical considerations, understanding local cultural customs and ensuring mutual respect with the locals. Frequent self-evaluation and long-term mission sustainability are critical. Finally, mission costs should be evaluated.

Endosteal blood supply of the mandible: anatomical study of nutrient vessels in the condylar neck accessory foramina.

PURPOSE: In the mandible, the condylar neck vascularization is commonly described as mainly periosteal; while the endosteal contribution is still debated, with very limited anatomical studies. Previous works have shown the contribution of nutrient vessels through accessory foramina and their contribution in the blood supply of other parts of the mandible. Our aim was to study the condylar neck's blood supply from nutrient foramina. METHODS: Six latex-injected heads were dissected and two hundred mandibular condyles were observed on dry mandibles searching for accessory bone foramina. RESULTS: Latex-injected dissections showed a direct condylar medular arterial supply through foramina. On dry mandibles, these foramina were most frequently observed in the pterygoid fovea in 91% of cases. However, two other accessory foramina areas were identified on the lateral and medial sides of the mandibular condylar process, confirming the vascular contribution of transverse facial and maxillary arteries. CONCLUSIONS: The maxillary artery indeed provided both endosteal and periosteal blood supply to the condylar neck, with three different branches: an intramedullary ascending artery (arising from the inferior alveolar artery), a direct nutrient branch and some pterygoid osteomuscular branches.

Congenital fibroblastic connective tissue nevi: Unusual and misleading presentations in three infantile cases.

BACKGROUND: Fibroblastic connective tissue nevi (FCTN) are benign skin conditions characterized by bland spindle cells infiltrating the reticular dermis and the upper subcutis with preservation of adnexal structures. A subset of FCTN expresses CD34, which may cause difficulties in the differential diagnosis, in particular with dermatofibrosarcoma (DFSP). We aim to study clinical and histological main features of congenital FCTN to better understand their heterogeneity. METHODS: We present 3 cases of congenital FCTN with misleading pseudo-tumoral presentations and compare them with published cases in literature. We provide a diagnostic algorithm for congenital neonatal connective tissue tumors. RESULTS: Clinically, FCTN mostly present as well-limited and nontender plaques or nodules mainly located in the neck and face areas or in the trunk. Histologically, FCTN are composed of irregularly distributed fascicles of bland spindled cells and are defined by a list of fundamental features: (i) no atypia, pleomorphism, or mitotic activity; (ii) skin appendages entrapped but unaffected; (iii) no evidence for malignancy. In most cases CD34 is positive, but in some cases, cells can express SMA or are even CD34- and SMA-. CONCLUSION: The initial presentation and natural history of FCTN fit better with a neoplasm than with a hamartoma. Thus, we suggest replacing the term "nevus" with tumor and considering fibroblastic connective tissue tumor (FCTT) as the right denomination of this clinico-pathological entity. FCTTs are difficult to diagnose due to their clinical heterogeneity. Clinical and histological malignant and benign differential diagnoses are discussed.

Minimum follow-up for closed rhinoseptoplasties.

BACKGROUND: There is no established consensus on the postoperative follow-up from which the aesthetic and functional outcomes of rhinoseptoplasty are considered as stable. OBJECTIVES: To contribute to defining the postoperative follow-up from which rhinoseptoplasty outcomes cease to evolve. METHODS: Postoperative assessments of Nasal Obstruction Symptom Evaluation (NOSE) and Rhinoplasty Outcome Evaluation (ROE) scores from 357 closed structural rhinoseptoplasty procedures were prospectively gathered from January 2019 to December 2023. These measurements encompassed the postoperative period from 1 to 12 months. All procedures were performed utilizing closed technique. RESULTS: No statistically significant difference was detected between the scores at 1, 2, and 6 months versus 12 months postoperatively (ROE: p = 0.388; 0.268; 0.162; NOSE: p = 0.265; 0.192; 0.975, Mann-Whitney test). Similarly, no follow-up impact was revealed between the scores at 1, 2, 6, and 12 months postoperatively (ROE: p = 0.548; NOSE: p = 0.280, Kruskal-Wallis test). No significant correlation was established between follow-up (in months) and ROE and NOSE scores (ROE: p = 0.397; NOSE: p = 0.632, Spearman). CONCLUSION: Follow-up duration does not influence NOSE and ROE scores over the 1- to 12-month timeframe. The 1-month postoperative outcome can be regarded as a reliable indicator of the 12-month outcome. These conclusions apply to NOSE and ROE scores of rhinoseptoplasty conducted using closed technique for the 1- to 12-month period. Further research is needed for open techniques, preservation rhinoplasty, other patient-reported outcomes measures (PROMs) as well as for the follow-up beyond 12 months postoperatively.

Biomarkers of radioresistance in head and neck squamous cell carcinomas.

PURPOSE: Head and neck squamous cell carcinoma (HNSCC) is a major cause of morbidity and mortality. Although HNSCC is mainly caused by tobacco and alcohol consumption, infection by Human Papilloma Virus (HPV) has been also associated with the increasing incidence of oropharyngeal squamous cell carcinomas (OPSCC) during the past decades. HPV-positive HNSCC is characterized by a higher radiosensitivity compared to HPV-negative tumor. While several clinical trials are evaluating de-escaladed radiation doses strategies in HPV-positive HNSCC, molecular mechanisms associated with relative radioresistance in HPV-negative HNSCC are still broadly unknown. Our goal was to review recently proposed biomarkers of radioresistance in this setting, which may be useful for stratifying tumor's patient according to predicted level of radioresistance. CONCLUSIONS: most of biomarkers of radioresistance in HPV-negative HNSCC are identified using a hypothesis-driven approach, based on molecular mechanisms known to play a key role during carcinogenesis, compared to an unsupervised data-driven approach regardless the biological rational. DNA repair and hypoxia are the two most widely investigated biological and targetable pathways related to radioresistance in HNSCC. The better understanding of molecular mechanisms and biomarkers of radioresistance in HPV-negative HNSCC could help for the development of radiosensitization strategies, based on targetable biomarkers, in radioresistant tumors as well as de-escalation radiation dose strategies, based on biological level of radioresistance, in radiosensitive tumors.

Extensive head and neck skin cancers: Carcinologic surgery as a cornerstone of treatment.

BACKGROUND AND OBJECTIVE: The prevalence of extensive skin cancers increases with the aging of the population. Surgical management is the gold standard of curative treatment while morbidity is not negligible. There are few data in the literature concerning extensive head and neck cutaneous cancers. The aim of this article is to report our experience of curative management of head and neck extensive skin cancers. METHOD: In this single-center retrospective observational study, we report a series of 17 patients with extensive skin facial cancers treated by surgery between 2013 and 2022 in the maxillofacial surgery department of the Pitié-Salpêtrière Hospital. We collected clinical, therapeutic, histological, and carcinologic data. RESULTS: The median age of the patients was 66 years [35-94]. There were 9 male and 8 women. Scalp (39 %) and cheek (22 %) locations were the most frequent ones. The most frequent histological types were squamous cell carcinoma (61 %) and basal cell carcinoma (17 %). Three patients received neoadjuvant treatment. The surgical treatment consisted mainly of carcinological resection followed by one-stage reconstruction by free flap for 5 (30 %) patients and without reconstruction for primary for 12 (70 %) patients, of whom 8 benefited from secondary reconstruction. Five patients received adjuvant radiotherapy or radio-chemotherapy. With a median follow-up of 40 months (2-72), the median overall survival was 40 months (12-72). CONCLUSION: We know that extensive skin cancers of the face have a good prognosis on condition that the carcinological and reconstructive requirements are respected. Surgery remains the cornerstone of treatment while the improvement of adjuvant therapies, in particular the rise of immunotherapies or other targeted therapies, may allow to limit recurrences.

Epidemiology of facial skin cancers managed in a French ambulatory surgical center.

INTRODUCTION: Approximately 80,000 cases of skin cancer are diagnosed annually in France. The management of these cancers can occur in both university hospital centers and ambulatory surgery centers. Limited data exist regarding the epidemiology of cutaneous cancers treated through ambulatory surgery centers. The objective of our study is to describe the epidemiological characteristics of cutaneous cancers managed in a tertiary ambulatory surgery center. METHODS: This is a retrospective, single-center observational study. The included patients were those who underwent surgical excision of one or more skin cancers within the maxillofacial department of a tertiary ambulatory surgery center. Clinical, therapeutic, histopathological, and follow-up data (additional surgery if margins were not clear, progression, recurrence, second cancer…) were collected. RESULTS: Among the n = 1931 patients operated for a head and neck skin tumor from September 2018 to July 2022, n = 426 (22 %) were diagnosed with cancer upon histological analysis. The median age was 76 years (31-100), with a male-to-female ratio of 1/1. The most frequent locations were the nose (23 %) and cheek (20 %). Ten percent of patients had dual-site skin cancer at initial diagnosis. The most common histological types were basal cell carcinoma (77 %) and squamous cell carcinoma (18 %). Surgical treatment primarily consisted of "excision-reconstruction with local flap" (51 %) or "excision-suture" (34 %). Resection margins were mostly clear (65 %), and only six patients (2 %) experienced local recurrence or progression during follow-up. CONCLUSIONS: Skin cancers are prevalent in ambulatory practice. Surgical treatment allows for effective control of the cancer. Photoprotection, particularly in immunocompromised patients, remains crucial for prevention.

Teaching how to break bad news in Oncology: In-class vs. virtual peer role-plays.

BACKGROUND: We report two different peer role-play training courses for breaking bad news (BBN) in Oncology, the classic "in-class" model and the "virtual" peer role-play (VPRP) model developed during the SARS-CoV-2 pandemic. METHODS: Each session included 20-25 4th year medical students supervised by two practitioners experienced in oncology. After an ice breaking activity to exchange with students on means to promote hope to patients when BBN, peer role-plays started. Pre-and post-session questionnaires were submitted to evaluate students' satisfaction, attitudes, and perceptions. Pre-and post-session knowledge test were realized. Each student has participated to only one peer-role play either "in-class" (2018) or VPRP (2020). RESULTS: In 2018, a total of 222 students received the "in-class" training. In 2020, a total 431 students received the VPRP training. For almost all students it was the first peer role-play training session. Before training, reported level of confidence in BBN was low. After training, students of the VPRP group were highly satisfied regarding quality (realism, organization). Students also reported great interest and perceived benefits. Students who underwent "in-class" training course showed a significantly higher improvement (+1.9 points) of their knowledge scores compared to those who underwent the VPRP training course (+0.7 points) (P-value=2e-16). CONCLUSION: The two methods seem beneficial to improve knowledge skills in BBN although "in-class" training class seem to be more efficient. To our knowledge, this is the first comparison between virtual and in-class peer-role play training for BBN in oncology.

Delto-acromial artery perforator flap combined with a radial forearm free flap as a "vascular bridge" for nasal reconstruction.

Nasal reconstruction for total rhinectomy is challenging, especially if locoregional flaps are unavailable. Herein, we report the case of a nasal reconstruction combining a forearm free flap as "vascular bridge" and a Delto-Acromial Artery Perforator (DAAP) flap in its free form. The forearm free flap was used to restore missing elements of the nasal lining while the distal part of the radial pedicle has served as a donor vessel for the DAAP free flap which restores the nasal covering. A chondrocostal graft was used as a nasal framework. The nasal aspect at 24 months postop support the patient's satisfaction. The main advantages of the DAAP Flap are the pliability, relative hairless nature, skin thinness and its geographical proximity with the nose avoiding major dyschromia. Moreover, the anatomy consistency makes it easier to harvest, the underlying muscles are respected, and it allows for tension free primary closure without shoulder movement limitation.

Head and neck Ewing sarcoma: French surgical practice analysis pleads for surgery centralization.

This study aimed to analyze surgical procedures for head and neck Ewing sarcoma (HNES) with regard to oncological, functional, and esthetic outcomes. A blinded multidisciplinary retrospective chart review of operated French HNES patients (Euro-EWING 99 trial, 1999-2014) was performed to assess patient/tumor characteristics, treatment details, and outcomes. Primary surgery without reconstruction was undertaken in 13 patients (emergency context/misdiagnosis). However, because of contaminated surgical margins, all patients had to undergo systematic postoperative radiotherapy. Twenty-six patients underwent multidisciplinary evaluation and were scheduled to undergo postchemotherapy surgery, with 19 patients scheduled for immediate reconstruction. All cases showed R0 margins after postchemotherapy surgery of the initial tumor bed by multidisciplinary surgical teams, while n = 3/4 of local relapses (very poor prognosis) had R1a margins after surgery of the residual tumor volume following chemotherapy. Only three surgical expertise centers operated on ≥ 4 patients over the 15-year period. Thirty patients developed long-term sequelae, with increased complications following radiotherapy. Referring patients to surgical expertise centers following a suspected diagnosis, with planned postchemotherapy surgery of the initial tumor bed at these centers, might limit the need for intralesional resections, allowing radical R0 resections and thus reducing long-term sequelae as well as the risk of secondary radio-induced malignancy by limiting the need for postoperative radiotherapy.

Vestibuloplasty for immediate dental implantation in fibular free flap for oral cancer patients undergoing mandibulectomy reconstruction: A technical note.

Vestibuloplasty is fundamental to restore an oral vestibule for immediate dental implantation in fibular free flap (FFF) for oral cancer patients undergoing mandibulectomy reconstruction. Double surgical team including reconstructive head and neck surgeon and a dental surgeon is fundamental. The first step of the vestibuloplasty is to identify the skin perforator. The second step is to thin the FFF skin island as much as necessary to facilitate: i-the reinset into the gingivobuccal sulcus while creating enough space in the oral vestibule for the future dental prosthesis and ii-the exposition of dental implants. The third step is to create a percutaneous access to the implants through the FFF skin paddle using a dermatologic punch while preserving a large oral vestibule. The fourth step is the skin reinsertion into the gingivobuccal sulcus and closure. Realizing vestibuloplasty before radiotherapy allows prevention of soft tissue contraction and osteoradionecrosis while reducing the necessary time for a complete dental rehabilitation and improving patient quality of life.

Unmet Needs and Perspectives in Oral Cancer Prevention.

Oral potentially malignant disorders (OPMD) may precede oral squamous cell carcinoma (OSCC). Reported rates of malignant transformation of OPMD range from 3 to 50%. While some clinical, histological, and molecular factors have been associated with a high-risk OPMD, they are, to date, insufficiently accurate for treatment decision-making. Moreover, this range highlights differences in the clinical definition of OPMD, variation in follow-up periods, and molecular and biological heterogeneity of OPMD. Finally, while treatment of OPMD may improve outcome, standard therapy has been shown to be ineffective to prevent OSCC development in patients with OPMD. In this perspective paper, several experts discuss the main challenges in oral cancer prevention, in particular the need to (i) to define an OPMD classification system by integrating new pathological and molecular characteristics, aiming (ii) to better identify OPMD at high risk of malignant transformation, and (iii) to develop treatment strategies to eradicate OPMD or prevent malignant transformation.

Immunologically active phenotype by gene expression profiling is associated with clinical benefit from PD-1/PD-L1 inhibitors in real-world head and neck and lung cancer patients.

INTRODUCTION: Identification of tumours harbouring an overall active immune phenotype may help for selecting patients with advanced head and neck squamous cell carcinomas (HNSCC) and non-small cell lung cancer (NSCLC) who may benefit from immunotherapies. Our objective was to develop a reliable and stable scoring system to identify those immunologically active tumours. METHODS: Using gene expression profiles of 421 HNSCC, we developed a score to identify immunologically active tumours. Validation of the 'HOT' score was done in 40 HNSCC and 992 NSCLC. Stability of the 'HOT' score was tested in paired HNSCC samples from diagnostic biopsies versus surgically resected specimens, untreated versus recurrent samples, and pre-versus post-cetuximab samples in a total of 76 patients. The association between the 'HOT' score with overall survival (OS) and progression-free survival (PFS) was tested in 184 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors. RESULTS: A 27-gene expression based 'HOT' score was correlated with: (i) PD-L1 and IDO1 expression, (ii) TCD8 infiltrate and (iii) activation of the IFN-γ pathway. The HOT score concordance when comparing diagnostic biopsies and surgically resected specimens was higher than in untreated samples versus recurrent or pre-versus post-cetuximab samples. In 102 and 82 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors, the HOT score was associated with an improved OS and PFS in multivariate analysis. CONCLUSION: The 'HOT' score is a simple and robust approach to identify real-world patients with HNSCC and NSCLC immunologically active tumours who may benefit from PD-1/PD-L1 inhibitors.

Datasets for gene expression profiles of head and neck squamous cell carcinoma and lung cancer treated or not by PD1/PD-L1 inhibitors.

Identification of tumors harboring an overall active immune phenotype may help for selecting patients with advanced head and neck squamous cell carcinomas (HNSCC) and non-small cell lung cancer (NSCLC) who may benefit from immunotherapies. In this context, we generated targeted gene expression profiles in three and two independent cohorts of patients with HNSCC or NSCLC respectively, treated or not by PD-1/PD-L1 inhibitors. Notably, we generated two datasets including 102 and 82 patients with HNSCC or NSCLC treated with PD-1/PD-L1 inhibitors. Clinical information, including detailed survival raw data, is available for each patient, allowing to test association between gene expression data and patient survival (overall and progression-free survival). Moreover, we also generated gene expression datasets of 27 paired HNSCC samples from diagnostic biopsies and versus surgically resected specimens as well as 33 paired HNSCC samples at initial diagnosis (untreated) and at recurrence. Those datasets may allow to test the stability of a given biomarker across paired samples.

MEK1/2 inhibition transiently alters the tumor immune microenvironment to enhance immunotherapy efficacy against head and neck cancer.

BACKGROUND: Although the mitogen-activated protein kinases (MAPK) pathway is hyperactive in head and neck cancer (HNC), inhibition of MEK1/2 in HNC patients has not shown clinically meaningful activity. Therefore, we aimed to characterize the effect of MEK1/2 inhibition on the tumor microenvironment (TME) of MAPK-driven HNC, elucidate tumor-host interaction mechanisms facilitating immune escape on treatment, and apply rationale-based therapy combination immunotherapy and MEK1/2 inhibitor to induce tumor clearance. METHODS: Mouse syngeneic tumors and xenografts experiments were used to analyze tumor growth in vivo. Single-cell cytometry by time of flight, flow cytometry, and tissue stainings were used to profile the TME in response to trametinib (MEK1/2 inhibitor). Co-culture of myeloid-derived suppressor cells (MDSC) with CD8+ T cells was used to measure immune suppression. Overexpression of colony-stimulating factor-1 (CSF-1) in tumor cells was used to show the effect of tumor-derived CSF-1 on sensitivity to trametinib and anti-programmed death- 1 (αPD-1) in mice. In HNC patients, the ratio between CSF-1 and CD8A was measured to test the association with clinical benefit to αPD-1 and αPD-L1 treatment. RESULTS: Using preclinical HNC models, we demonstrated that treatment with trametinib delays HNC initiation and progression by reducing tumor cell proliferation and enhancing the antitumor immunity of CD8+ T cells. Activation of CD8+ T cells by supplementation with αPD-1 antibody eliminated tumors and induced an immune memory in the cured mice. Mechanistically, an early response to trametinib treatment sensitized tumors to αPD-1-supplementation by attenuating the expression of tumor-derived CSF-1, which reduced the abundance of two CSF-1R+CD11c+ MDSC populations in the TME. In contrast, prolonged treatment with trametinib abolished the antitumor activity of αPD-1, because tumor cells undergoing the epithelial to mesenchymal transition in response to trametinib restored CSF-1 expression and recreated an immune-suppressive TME. CONCLUSION: Our findings provide the rationale for testing the trametinib/αPD-1 combination in HNC and highlight the importance of sensitizing tumors to αPD-1 by using MEK1/2 to interfere with the tumor-host interaction. Moreover, we describe the concept that treatment of cancer with a targeted therapy transiently induces an immune-active microenvironment, and supplementation of immunotherapy during this time further activates the antitumor machinery to cause tumor elimination.

Precision Medicine Approaches to Overcome Resistance to Therapy in Head and Neck Cancers.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most incident cancer worldwide. More than half of HNSCC patients experience locoregional or distant relapse to treatment despite aggressive multimodal therapeutic approaches that include surgical resection, radiation therapy, and adjuvant chemotherapy. Before the arrival of immunotherapy, systemic chemotherapy was previously employed as the standard first-line protocol with an association of cisplatin or carboplatin plus 5-fluorouracil plus cetuximab (anti-EFGR antibody). Unfortunately, acquisition of therapy resistance is common in patients with HNSCC and often results in local and distant failure. Despite our better understanding of HNSCC biology, no other molecular-targeted agent has been approved for HNSCC. In this review, we outline the mechanisms of resistance to the therapeutic strategies currently used in HNSCC, discuss combination treatment strategies to overcome them, and summarize the therapeutic regimens that are presently being evaluated in early- and late-phase clinical trials.

Bilateral bifid condyles: A rare etiology of temporomandibular joint disorders.

Background: Bifid mandibular condyle (BMC) is a rare etiology of temporomandibular joint (TMJ) disorders characterized by a duplication of the head of the mandibular condyle.Case report: The authors report the case of a 20-year-old patient complaining of a painful and clicking TMJ and mandibular hypomobility, which had been progressing for several months. Radiological investigations (dental panoramic radiograph and X-ray CT scan) revealed right and left abnormalities of the TMJ due to bilateral BMC requiring surgical management.Conclusion: Despite a prevalence of 0.31% to 1.82% and the controversies surrounding its pathophysiology, maxillofacial surgeons should be aware of BMC to avoid misdiagnosis related to the clinical presentation (pain, clicking, hypomobility, or ankylosis) and provide adequate management.

DIVA, a 3D virtual reality platform, improves undergraduate craniofacial trauma education.

Craniofacial fractures management is challenging to teach due to the complex anatomy of the head, even when using three-dimensional CT-scan images. DIVA is a software allowing the straightforward visualization of CT-scans in a user-friendly three-dimensional virtual reality environment. Here, we assess DIVA as an educational tool for craniofacial trauma for undergraduate medical students. Three craniofacial trauma cases (jaw fracture, naso-orbital-ethmoid complex fracture and Le Fort 3 fracture) were submitted to 50 undergraduate medical students, who had to provide diagnoses and treatment plans. Each student then filled an 8-item questionnaire assessing satisfaction, potential benefit, ease of use and tolerance. Additionally, 4 postgraduate students were requested to explore these cases and to place 6 anatomical landmarks on both virtual reality renderings and usual slice-based three-dimensional CT-scan visualizations. High degrees of satisfaction (98%) without specific tolerance issues (86%) were reported. The potential benefit in a better understanding of craniofacial trauma using virtual reality was reported by almost all students (98%). Virtual reality allowed a reliable localization of key anatomical landmarks when compared with standard three-dimensional CT-scan visualization. Virtual reality interfaces such DIVA are beneficial to medical students for a better understanding of craniofacial trauma and allow a reliable rendering of craniofacial anatomy.

Longitudinal assessment of PD-L1 expression and gene expression profiles in patients with head and neck cancer reveals temporal heterogeneity.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is the most validated predictive biomarker used for the treatment of head and neck squamous cell carcinoma (HNSCC) with immune checkpoint inhibitors (ICI). Several gene expression-based signatures surrogate of the activation of IFN-gamma pathway and of the presence of tertiary lymphoid structures (TLS) have also been proposed as potential biomarkers. While they may have a potential therapeutic implication, the longitudinal changes of either PD-L1 or gene expression profiles between the initial and recurrent HNSCC lesions is unknown. METHODS: PD-L1 immunohistochemistry (IHC) and targeted RNA-sequencing of 2,549 transcripts were analyzed on paired specimens from the initial diagnosis and recurrent HNSCC. PD-L1 status was defined using the combined positive score (CPS). PD-L1 mRNA levels were compared with protein expression levels by IHC. Enrichment scores of surrogate signatures for TLS and IFN-gamma (IFN-γ) pathway activation were computed using the single sample gene set enrichment analysis (ssGSEA). RESULTS: PD-L1 status was 64% (21/33) concordant between the initial and recurrent lesions using a CPS 1 threshold and 67% (22/33) concordant using a CPS 20 threshold. CPS score was associated with PD-L1 gene expression levels. There was a 43% (15/35) and 66% (23/35) concordance for the IFN-γ and TLS signature scores, respectively. CONCLUSION: Our study reveals temporal heterogeneity of PD-L1 status and TLS/IFN-γ gene expression surrogates in HNSCC that need to be considered when interpreting biomarker studies.

Early changes in the immune microenvironment of oral potentially malignant disorders reveal an unexpected association of M2 macrophages with oral cancer free survival.

Understanding the dynamics of the immune microenvironment is critical to the development of immuno-based strategies for the prevention of oral potentially malignant disorders transformation to oral squamous cell carcinoma (OSCC). We used laser capture microdissection and RNA-sequencing to profile the expression of 13 matched pairs of epithelial versus stromal compartments from normal mucosa, hyperplasia, dysplasia, and invasive tumors in the 4-nitroquinolein (4-NQO) murine model of oral carcinogenesis. Genes differentially expressed at each step of transformation were defined. Immune cell deconvolution and enrichment scores of various biological processes including immune-related ones were computed. Immunohistochemistry was also performed to characterize the immune infiltrates by T-cells (T-cells CD3+, helper CD4+, cytotoxic CD8+, regulatory FoxP3+), B-cells (B220+), and macrophages (M1 iNOS+, M2 CD163+) at each histological step. Enrichment of three independent M2 macrophages signatures were computed in 86 oral leukoplakia with available clinical outcome. Most gene expression changes were observed in the stromal compartment and related to immune biological processes. Immune cell deconvolution identified infiltration by the macrophage population as the most important quantitatively especially at the stage of dysplasia. In 86 patients with oral leukoplakia, three M2 macrophages signatures were independently associated with improved oral cancer-free survival. This study provides a better understanding of the dynamics of the immune microenvironment during oral carcinogenesis and highlights an unexpected association of M2 macrophages gene expression signatures with oral cancer free survival in patients with oral leukoplakia.