Inhibition of the CCR6-CCL20 axis prevents regulatory T cell recruitment and sensitizes head and neck squamous cell carcinoma to radiation therapy.

BACKGROUND:  Radioresistance of HNSCCs remains a major challenge for effective tumor control. Combined radiotherapy (RT) and immunotherapy (IT) treatment improved survival for a subset of patients with inflamed tumors or tumors susceptible to RT-induced inflammation. To overcome radioresistance and improve treatment outcomes, an understanding of factors that suppress anti-tumor immunity is necessary. In this regard, regulatory T cells (Tregs) are critical mediators of immune suppression in HNSCCs. In this study, we investigated how radiation modulates Treg infiltration in tumors through the chemokine CCL20. We hypothesized that radiation induces CCL20 secretion resulting in Treg infiltration and suppression of anti-tumor immunity. METHODS:  Human and mouse HNSCC cell lines with different immune phenotypes were irradiated at doses of 2 or 10 Gy. Conditioned media, RNA and protein were collected for assessment of CCL20. qPCR was used to determine CCL20 gene expression. In vivo, MOC2 cells were implanted into the buccal cavity of mice and the effect of neutralizing CCL20 antibody was determined alone and in combination with RT. Blood samples were collected before and after RT for analysis of CCL20. Tumor samples were analyzed by flow cytometry to determine immune infiltrates, including CD8 T cells and Tregs. Mass-spectrometry was performed to analyze proteomic changes in the tumor microenvironment after anti-CCL20 treatment. RESULTS:  Cal27 and MOC2 HNSCCs had a gene signature associated with Treg infiltration, whereas SCC9 and MOC1 tumors displayed a gene signature associated with an inflamed TME. In vitro, tumor irradiation at 10 Gy significantly induced CCL20 in Cal27 and MOC2 cells relative to control. The increase in CCL20 was associated with increased Treg migration. Neutralization of CCL20 reversed radiation-induced migration of Treg cells in vitro and decreased intratumoral Tregs in vivo. Furthermore, inhibition of CCL20 resulted in a significant decrease in tumor growth compared to control in MOC2 tumors. This effect was further enhanced after combination with RT compared to either treatment alone. CONCLUSION:  Our results suggest that radiation promotes CCL20 secretion by tumor cells which is responsible for the attraction of Tregs. Inhibition of the CCR6-CCL20 axis prevents infiltration of Tregs in tumors and suppresses tumor growth resulting in improved response to radiation.

Oncologic Significance of Therapeutic Delays in Patients With Oral Cavity Cancer.

Importance: Oral cavity cancer often requires multidisciplinary management, subjecting patients to complex therapeutic trajectories. Prolonged treatment intervals in oral cavity cancer have been associated with poor oncological outcomes, but there has yet to be a study investigating treatment times in Canada. Objective: To report treatment delays for patients with oral cavity cancer in Canada and evaluate the outcomes of treatment delays on overall survival. Design, Setting, and Participants: This multicenter cohort study was performed at 8 Canadian academic centers from 2005 to 2019. Participants were patients with oral cavity cancer who underwent surgery and adjuvant radiation therapy. Analysis was performed in January 2023. Main Outcomes and Measures: Treatment intervals evaluated were surgery to initiation of postoperative radiation therapy interval (S-PORT) and radiation therapy interval (RTI). The exposure variables were prolonged intervals, respectively defined as index S-PORT greater than 42 days and RTI greater than 46 days. Patient demographics, Charlson Comorbidity Index, smoking status, alcohol status, and cancer staging were also considered. Univariate (log rank and Kaplan-Meier) and multivariate (Cox regression) analyses were performed to determine associations with overall survival (OS). Results: Overall, 1368 patients were included; median (IQR) age at diagnosis was 61 (54-70) years, and 896 (65%) were men. Median (IQR) S-PORT was 56 (46-68) days, with 1093 (80%) patients waiting greater than 42 days, and median (IQR) RTI was 43 (41-47) days, with 353 (26%) patients having treatment time interval greater than 46 days. There were variations in treatment time intervals between institutions for S-PORT (institution with longest vs shortest median S-PORT, 64 days vs 48 days; η2 = 0.023) and RTI (institution with longest vs shortest median RTI, 44 days vs 40 days; η2 = 0.022). Median follow-up was 34 months. The 3-year OS was 68%. In univariate analysis, patients with prolonged S-PORT had worse survival at 3 years (66% vs 77%; odds ratio 1.75; 95% CI, 1.27-2.42), whereas prolonged RTI (67% vs 69%; odds ratio 1.06; 95% CI, 0.81-1.38) was not associated with OS. Other factors associated with OS were age, Charlson Comorbidity Index, alcohol status, T category, N category, and institution. In the multivariate model, prolonged S-PORT remained independently associated with OS (hazard ratio, 1.39; 95% CI, 1.07-1.80). Conclusions and Relevance: In this multicenter cohort study of patients with oral cavity cancer requiring multimodal therapy, initiation of radiation therapy within 42 days from surgery was associated with improved survival. However, in Canada, only a minority completed S-PORT within the recommended time, whereas most had an appropriate RTI. An interinstitution variation existed in terms of treatment time intervals. Institutions should aim to identify reasons for delays in their respective centers, and efforts and resources should be directed toward achieving timely completion of S-PORT.

The infraclavicular pedicled flap in head and neck reconstruction: applications and outcomes.

BACKGROUND: An infraclavicular pedicled flap (ICPF) was recently described in the literature. This anatomical region is attractive for the restoration of head and neck oncological defects. This paper is a review of our experience with this versatile flap. METHODS: A retrospective study was conducted by reviewing the records of all the patients operated in a tertiary-care center between August 2013 and January 2019 whose surgery involved an ICPF. RESULTS: Forty-four patients received an ICPF for various indications, including large vessel coverage in neck/parotid recontouring (34.1%), postlaryngectomy reconstruction (34.1%), and fistula closure (25.0%). All flaps survived. Thirteen patients experienced a postoperative complication (29.5%), six of whom (13.9%) required a repeat procedure under general anesthesia. CONCLUSION: ICPF is suitable for several indications and is a useful adjunctive tool in head and neck reconstruction. It proved to have a high survival rate, with complication rates similar to other regional flaps.

Evaluation of PACE4 isoforms as biomarkers in thyroid cancer.

BACKGROUND: To date, no single molecular marker has been demonstrated as clinically useful in differentiating malignant from benign thyroid nodules when a fine needle aspiration falls in the "unknown significance" categories of the Bethesda Classification. PACE4, a member of the proprotein convertase family of enzymes, has been shown to play a major role in the pathogenesis of prostate cancer, through the formation of an oncogenic isoform named PACE4-altCT. PACE4 isoforms have also been suggested to play a role in other cancers, including thyroid cancer, but have never been investigated in a detailed manner. Our objective is to compare the histochemical distribution of the two major PACE4 isoforms in benign and malignant thyroid nodules, in order to determine their potential usefulness as discriminatory biomarkers. METHODS: Thyroid tissues of patients who underwent thyroidectomy were classified according to final pathology. Corresponding tissue sections were immunostained, using two previously validated antibodies raised against the C-terminal end of the two PACE4 isoforms, namely the full-length PACE4 protein (PACE4-FL) and its alternative isoform (PACE4-altCT). Nodules were compared with adjacent normal parenchyma and immunostaining was rated as "low" or "high" by a head and neck pathologist. RESULTS: Non-lesional thyroid parenchyma did not express PACE4-FL (p = 0.002). As a group, malignant (n = 17) nodules expressed PACE4-FL significantly more than benign (n = 24) nodules (percentage of high immunostaining: 52.9% vs 4.2%; p = 0.001). Reciprocally, there was a statistically lower expression of PACE4-altCT in malignant nodules than in adjacent non-lesional parenchyma (p = 0.014). The specificity of a high PACE4-FL immunostaining in determining malignancy was 95.8% (95% CI, 78.9% to 99.9%). CONCLUSION: This study supports the previously described relationship between PACE4-FL and PACE4-altCT through alternative splicing. It also suggests that PACE4-FL is a promising biomarker for thyroid malignancy. Its high specific expression for malignancy could make it an interesting "rule in" test for thyroid cancer. Further prospective, quantitative studies are currently being designed to address how measurements of PACE4 isoforms could be used in a clinical setting. TRIAL REGISTRATION: This study does not report the results of a health care intervention on human participants. It was nonetheless registered on ClinicalTrials.gov under reference number NCT03160482 .

Infraclavicular free flap for head and neck reconstruction: surgical description and early outcomes in 7 consecutive patients.

BACKGROUND: The primary purposes of this study were to introduce a novel fasciocutaneous free flap from the infraclavicular region based on the anterior perforator (AP) branch of the transverse cervical artery (TCA) and the retrograde external jugular vein (EJV), describe a reliable approach to flap design and elevation, and assess early clinical results. METHODS: This was a prospective observational study of 7 consecutive cases of head and neck reconstruction using the infraclavicular free flap (ICFF) based on the AP of the TCA. RESULTS: Seven patients underwent ICFF reconstruction within a 6-month period. There was 100% flap survival in all cases at 14 days. Mean dimensions of the flap were 13.3 × 6.3 cm. The EJV drained the flap in all cases but the transverse cervical vein (TCV) was used in 1 case. The retrograde EJV was used in 5 cases to increase the venous pedicle length. No vein grafts were required. CONCLUSION: ICFF demonstrated similar outcomes compared to conventional fasciocutaneous free flaps. This flap has the potential for common application given its consistent anatomy and donor site advantages.

Comparison of fibular and scapular osseous free flaps for oromandibular reconstruction: a patient-centered approach to flap selection.

IMPORTANCE: Provides an approach to osseous free flap selection for reconstruction of segmental mandible defects that takes into consideration general medical status of the patient and reconstruction requirements; demonstrates the complementary qualities of fibular and subscapular system free flaps; and describes the different surgical indications for lateral border scapular and scapular tip free flaps. OBJECTIVES: To review our experience with osseous mandible reconstruction comparing the fibular and subscapular system free flaps, determine reconstruction-specific and general health variables that may differ between these patient groups, and present our approach to oromandibular reconstruction. DESIGN: Retrospective study. SETTING: Academic tertiary care medical center. PARTICIPANTS: A total of 110 patients (68 male, 42 female) undergoing single-stage oromandibular reconstructions with free-tissue transfers between May 1, 2006, and May 30, 2012. INTERVENTION: Single-stage oromandibular reconstruction with free-tissue transfer. MAIN OUTCOME MEASURES: Differences in patient demographics, bone and soft-tissue aspects of the reconstruction, operative time, flap outcomes, and major postoperative complications between fibular, lateral scapular border, and scapular tip free flaps. RESULTS: A total of 110 patients underwent 113 reconstructions, including 58 fibular free flaps (FFFs) (51.3%) and 55 subscapular system flaps (48.7%). Of the subscapular system free flaps, 27 flaps (49%) were scapular tip free flaps (STFFs) based on the angular artery branch of the thoracodorsal pedicle; the remaining 28 cases were lateral scapular border flaps (LSBFs). Patients undergoing reconstruction with FFFs were significantly younger than their subscapular system flap counterparts (56 vs 70 years, P < .001). Mean mandible defect lengths were similar for patients undergoing FFF and LSBF reconstruction (7.8 and 7.7 cm, respectively); STFFs were used to reconstruct significantly shorter defects (mean, 6.0 cm, P < .001). The FFFs were more commonly used for anterior mandible defects in which multiple osteotomies and limited soft tissue were required, while subscapular flaps were more commonly used for linear mandible defects with complex soft-tissue requirements. A single complete flap loss occurred in a patient who underwent reconstruction with an STFF; other complication rates were similar between groups. CONCLUSIONS AND RELEVANCE: The FFFs and subscapular flaps are complementary options for oromandibular reconstruction. The FFF is ideal for younger patients, extended defects, multiple osteotomies, and limited soft-tissue requirements. The subscapular system free flaps (LSBF and STFF) are excellent options for (1) elderly patients; (2) those with significant comorbidities, such as peripheral vascular disease; and (3) mandible defects associated with complex soft-tissue requirements. Furthermore, the STFF offers a reliable option to reconstruct short-segment defects, in particular, defects involving the angle of the mandible.

Radiation-induced xerostomia: is octreotide the solution?

OBJECTIVE: In this study, we looked for evidence that octreotide, a drug used specifically in acromegaly and other digestive pathologies, can have a radioprotective effect on salivary glands. This effect has already been proven on the pituitary gland, which is why we postulated that octreotide could act the same way on rat parotid glands. METHOD: A prospective randomized controlled study on animals was conducted. With a noninvasive technique, we collected saliva from the parotid glands of 18 anesthetized rats at time 0 (preirradiation) and 1 month (postirradiation). Each sampling technique lasted 40 minutes, with pilocarpine injection at time 0 and 20 minutes. Saliva was collected bilaterally. Eighteen rats, nine in the saline group and nine in the octreotide group, were randomized. The substance was injected 30 minutes before irradiation. Thirty gray were given with the gamma knife on the left parotid gland of each rat following a computerized targeting method. Each gland was examined after the last saliva collection to determine the percentage of five criteria: fibrosis, ducts, fat, vessels, and acini. RESULTS: Data are available for 17 rats (nine in the octreotide group and eight in the saline group). Statistical analysis was done with a t-test (independent and paired). We noted that the postirradiation secretion in the left (radiated) gland was diminished compared with the right (nonradiated) gland in the saline group (p = .014). Fibrosis was increased in the irradiated (left) gland in both groups (p = .024 in the octreotide group and p = .033 in the saline group). The percentage of duct cells was more important in the left (radiated) gland of the octreotide group (p = .046). A trend appeared for a decrease in acinic cells only in the control group (p = .063). CONCLUSION: Octreotide acted as a radioprotective agent on rat parotid glands 1 month after irradiation with 30 Gy given with the gamma knife.