Fructose 1,6-bisphosphate aldolase: A promising prognostic marker for oral cancer and its role in radiotherapy response

Oral cancer remains a significant global health concern and its early detection plays a crucial role in improving patient outcomes. Identifying reliable prognostic markers is essential to guide treatment decisions and enhance survival rates. Fructose 1,6-bisphosphate aldolase (FBA), a glycolytic enzyme, has emerged as a promising candidate for prognostic assessment of oral cancer. This review highlights the role of FBA in tumorigenesis, its potential utility in predicting disease progression and patient survival, and its influence on response to radiotherapy. Recent studies have suggested that dysregulated metabolic pathways involving FBA may contribute to radiation resistance in oral cancer, emphasizing the need for further exploration of FBA-targeted therapeutic strategies. Understanding the role of FBA in oral cancer pathogenesis could pave the way for the development of personalized treatment strategies, including combined radiotherapy.

Disease Control and Late Toxicity in Adaptive Dose Painting by Numbers Versus Nonadaptive Radiation Therapy for Head and Neck Cancer: A Randomized Controlled Phase 2 Trial

PURPOSE

Local recurrence remains the main cause of death in stage III-IV nonmetastatic head and neck cancer (HNC), with relapse-prone regions within high 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)-signal gross tumor volume. We investigated if dose escalation within this subvolume combined with a 3-phase treatment adaptation could increase local (LC) and regional (RC) control at equal or minimized radiation-induced toxicity, by comparing adaptive 18F-FDG-PET voxel intensity-based dose painting by numbers (A-DPBN) with nonadaptive standard intensity modulated radiation therapy (S-IMRT).

METHODS AND MATERIALS

This 2-center randomized controlled phase 2 trial assigned (1:1) patients to receive A-DPBN or S-IMRT (+/-chemotherapy). Eligibility: nonmetastatic HNC of oral cavity, oro-/hypopharynx, or larynx, needing radio(chemo)therapy; T1-4N0-3 (exception: T1-2N0 glottic); KPS ≥ 70; ≥18 years; and informed consent.

PRIMARY OUTCOMES

1-year LC and RC. The dose prescription for A-DPBN was intercurrently adapted in 2 steps to an absolute dose-volume limit (≤1.75 cm3 can receive >84 Gy and normalized isoeffective dose >96 Gy) as a safety measure during the study course after 4/7 A-DPBN patients developed ≥G3 mucosal ulcers.

RESULTS

Ninety-five patients were randomized (A-DPBN, 47; S-IMRT, 48). Median follow-up was 31 months (IQR, 14-48 months); 29 patients died (17 of cancer progression). A-DPBN resulted in superior LC compared with S-IMRT, with 1- and 2-year LC of 91% and 88% versus 78% and 75%, respectively (hazard ratio, 3.13; 95% CI, 1.13-8.71; P = .021). RC and overall survival were comparable between arms, as was overall grade (G) ≥3 late toxicity (36% vs 20%; P = .1). More ≥G3 late mucosal ulcers were observed in active smokers (29% vs 3%; P = .005) and alcohol users (33% vs 13%; P = .02), independent of treatment arm. Similarly, in the A-DPBN arm, significantly more patients who smoked at diagnosis developed ≥G3 (46% vs 12%; P = .005) and ≥G4 (29% vs 8%; P = .048) mucosal ulcers. One arterial blowout occurred after a G5 mucosal toxicity.

CONCLUSIONS

A-DPBN resulted in superior 1- and 2-year LC for HNC compared with S-IMRT. This supports further exploration in multicenter phase 3 trials. It will, however, be challenging to recruit a substantial patient sample for such trials, as concerns have arisen regarding the association of late mucosal ulcers when escalating the dose in continuing smokers.

Metformin Radiosensitizing Effect on Hypoxic Oral Squamous Cell Carcinoma Cells by GAPDH and TAGLN2

OBJECTIVE

Tumor hypoxia is associated with a poorer prognosis in cancer patients and can diminish the efficacy of radiation therapy (RT). This study investigates the potential of metformin to enhance radiosensitivity in hypoxic cancer cells.

METHODS

Preliminary experiments were conducted to validate the impact of hypoxia on radiation response. Reactive oxygen species (ROS) levels, cell migration, and cell death were assessed in hypoxic, radiated cells treated with metformin. Proteomic and ontological analyses were employed to identify molecular targets associated with the radiosensitizing effect of metformin. Proteomic and ontological findings were validated through patient samples and in vitro studies.

RESULTS

Metformin amplified cell death, induced DNA fragmentation, decreased cell migration, and elevated ROS levels in hypoxic, radiated cells. Proteomic analyses revealed that GAPDH and TAGLN2 were identified as pivotal targets linked to the radiosensitizing effect of metformin. Oral cancer patients exhibited elevated levels of TAGLN2 and reduced levels of GAPDH. Metformin downregulated TAGLN2 and upregulated GAPDH in hypoxic, radiated cells. Additionally, metformin reduced levels of mutated p53.

CONCLUSIONS

This study suggests that metformin can enhance radiosensitivity in hypoxic cells, operating through modulation of GAPDH and TAGLN2. Furthermore, metformin effectively reduces mutated p53 levels in radiated cells under hypoxic conditions.

Feasibility of the analytical dose calculation method for Au-198 brachytherapy

PURPOSE

A dose calculation algorithm Computed Tomography (CT)-based analytical dose calculation method (CTanly), which can correct for subject inhomogeneity and size-dependent scatter doses, was applied to the 198Au seed. In this study, we evaluated the effectiveness of the CTanly method by comparing the gold standard Monte Carlo (MC) method and the conventional TG43 method on two virtual phantoms and patient CT images simulating oral cancer.

METHODS

As virtual phantoms, a water phantom and a heterogeneous phantom with soft tissue inserted cubic fat, lung, and bone were used. A 2-mm-thick lead plate was also inserted into the heterogeneous phantom as a dose attenuator. Virtual 198Au seeds and a 2-mm-thick lead plate were placed on the patient CT images. Dose distributions obtained via the TG43 and CTanly methods were compared with those of the MC by gamma analysis with 2%/2-mm thresholds. The computation durations were also compared.

RESULTS

In the water phantom, dose distributions comparable to those obtained via the MC method were obtained regardless of the algorithm. For the inhomogeneity phantom and patient case, the CTanly method showed an improvement in the gamma passing rate and dose distributions similar to those of the MC method were obtained. The computation time, which was days with the MC method, was reduced to minutes with the CTanly method.

CONCLUSIONS

The CTanly method is effective for 198Au seed dose calculations and takes a shorter time to obtain the dose distributions than the MC method.

Is immediate dental implant in fibula free flap beneficial for implant survival and osteoradionecrosis in jaw reconstruction?

OBJECTIVES

This study aimed to compare the risk of osteoradionecrosis and implant survival in oral cancer patients undergoing immediate dental implants during jaw reconstruction, termed "Jaw in a Day" (JIAD), with those receiving no implants or delayed implants (non-JIAD).

PATIENTS & METHODS

Clinicopathologic data were collected from prospectively enrolled JIAD patients (n = 10, 29 implants) and retrospectively from non-JIAD patients (n = 117, 86 implants). Survival analyses were performed to assess implant survival and osteoradionecrosis-free survival.

RESULTS

Osteoradionecrosis occurred in 0 % of JIAD cases compared to 19.3 % in non-JIAD cases without implants and 71.4 % in non-JIAD cases with delayed implants (p = 0.008). Osteoradionecrosis-free survival was significantly better in the JIAD group than the non-JIAD group (p = 0.0059). Implants in the JIAD group all survived regardless of radiation therapy (29/29, 100 %) and 95.1 % (58/61) of implants survived in delayed implants in non-irradiated fibula without radiotherapy. Meanwhile, only 11 of 25 implants placed in irradiated fibula flaps survived, even when the implants were placed after a median time interval of 624 days after radiotherapy, and none of them were earlier than 360 days. The survival analysis revealed a significant difference (p < 0.0001).

CONCLUSION

JIAD appears to offer superior outcomes in terms of implant survival and osteoradionecrosis prevention compared to delayed implant placement. Placing implants in irradiated fibula, even after years, significantly poses high risk of implant failure and osteoradionecrosis. JIAD represents a promising approach for optimal rehabilitation, particularly in oral cancer patients requiring postoperative radiotherapy. Proper positioning and orientation of implants and flaps are crucial for implant survival.

Site-specific radiation dosage and implant survival in oral cancer patients: A cohort study

OBJECTIVES

We assessed the radiation dosages (Dmean) on implant regions to identify the threshold for implant loss in patients with an intraoral malignancy treated with dental implants to support a mandibular denture during ablative surgery before volumetric-modulated arc therapy (VMAT).

MATERIALS AND METHODS

Data was collected prospectively from 28 patients treated surgically for an intraoral malignancy, followed by postoperative radiotherapy (VMAT) and analyzed retrospectively. Patients received 2 implants in the native mandible during ablative surgery. Implant-specific Dmean values were retrieved from the patients' files. Radiographic bone loss was measured 1 year after implant placement and during the last follow-up appointment. Implant survival was analyzed with the Kaplan-Meier method. Univariate logistic regression and Cox-regression analyses were performed to investigate the effect of increasing implant-specific radiation dosages on implant loss.

RESULTS

Five out of 56 placed implants were lost during follow-up (median 36.0 months, IQR 39.0). Radiographically, peri-implant bone loss occurred in implants with a Dmean > 40 Gy. Implant loss occurred only in implants with a Dmean > 50 Gy.

CONCLUSION

An implant-specific Dmean higher than 50 Gy is related to more peri-implant bone loss and, eventually, implant loss.

A Whole-Transcriptomic Analysis of Canine Oral Melanoma: A Chance to Disclose the Radiotherapy Effect and Outcome-Associated Gene Signature

Oral melanoma (OM) is the most common malignant oral tumour among dogs and shares similarities with human mucosal melanoma (HMM), validating the role of canine species as an immunocompetent model for cancer research. In both humans and dogs, the prognosis is poor and radiotherapy (RT) represents a cornerstone in the management of this tumour, either as an adjuvant or a palliative treatment. In this study, by means of RNA-seq, the effect of RT weekly fractionated in 9 Gray (Gy), up to a total dose of 36 Gy (4 weeks), was evaluated in eight dogs affected by OM. Furthermore, possible transcriptomic differences in blood and biopsies that might be associated with a longer overall survival (OS) were investigated. The immune response, glycosylation, cell adhesion, and cell cycle were the most affected pathways by RT, while tumour microenvironment (TME) composition and canonical and non-canonical WNT pathways appeared to be modulated in association with OS. Taking these results as a whole, this study improved our understanding of the local and systemic effect of RT, reinforcing the pivotal role of anti-tumour immunity in the control of canine oral melanoma (COM).

Multicriteria optimization of radiation therapy: Towards empowerment and standardization of reverse planning for head and neck squamous cell carcinoma

PURPOSE

The purpose of this study was to assess if multicriteria optimization could limit interoperator variability in radiation therapy planning and assess if this method could contribute to target volume coverage and sparing of organ at risk for intensity-modulated curative radiation therapy of head and neck cancers.

MATERIAL AND METHODS

We performed a retrospective analysis on 20 patients treated for an oropharyngeal or oral cavity squamous cell carcinoma. We carried out a comparative dosimetric study of manual plans produced with Precision® software, compared with the plans proposed using the multicriteria optimization method (RayStation®). We assessed interoperator reproducibility on the first six patients, and dosimetric contribution in sparing organs at risk using the multicriteria optimization method.

RESULTS

Median age was 69 years, most lesions were oropharyngeal carcinoma (65%), and 35% lesions were stage T3. First, we obtained a high degree of similarity between the four operator measurements for each patient at the level of each organ. Intraclass correlation coefficients were greater than 0.85. Second, we observed a significant dosimetric benefit for contralateral parotid gland, homolateral and contralateral masseter muscles, homolateral and contralateral pterygoid muscles and for the larynx (P<0.05). For the contralateral parotid gland, the mean dose difference between the multicriteria optimization and manual plans was -2.0Gy (P=0.01). Regarding the larynx, the mean dose difference between the two plans was -4.6Gy (P<0.001).

CONCLUSION

Multicriteria optimization is a reproducible technique and faster than manual optimization. It allows dosimetric advantages on organs at risk, especially for those not usually taken into consideration in manual dosimetry. This may lead to improved quality of life.

Fractionated irradiation induces radioresistant oral carcinoma cells with enhanced malignant phenotypes

OBJECTIVE

The fact that certain oral carcinoma patients experience radiotherapy failure implies that a more radioresistant and aggressive phenotype of surviving cancer cells potentially occurs during treatment. Our study aimed to establish radioresistant oral cancer cells through a fractionated irradiation protocol that mimics clinically relevant radiotherapy dosing strategies and to investigate all-round alterations in the malignant phenotype.

METHODS

Radioresistant oral carcinoma cells were generated by exposing Cal27 and Detroit 562 cells to 60 Gy radiation in 10 dose-escalating fractions and verified by cell immunofluorescence. Specific markers related to the epithelial-mesenchymal transition (EMT) process and the cancer stem cell (CSC) phenotype were assessed by Western blotting. Cell invasion and migration were evaluated using Matrigel-coated transwell and wound healing assays, respectively. Nontargeted metabolomics was used to mechanistically delineate the potential metabolic patterns linked to EMT and CSCs; the CSC phenotype was also examined by sphere formation assays and cell immunofluorescence.

RESULTS

Radioresistant oral carcinoma cell lines were successfully established and validated. These cells exhibited enhanced EMT and increase in both cell invasion and migration. These radioresistant cells further demonstrated a high metabolic profile, notably marked by lipid metabolism reprogramming and functional enrichment of ATP-binding cassette (ABC) transporters. Consistently, enhanced CSC phenotype in radioresistant cells was confirmed by elevated expression of stemness markers and increased sphere-forming capacity.

CONCLUSION

Radioresistant oral carcinoma cells subjected to fractionated radiation exhibit an augmented malignant phenotype. The metabolic characteristics linked to enhanced EMT and CSC phenotypes provide potential targets for improving radiotherapy in oral carcinoma.

Radiation-induced exosomes promote oral squamous cell carcinoma progression via enhancing SLC1A5-glutamine metabolism

BACKGROUND

Radiotherapy (RT) can drive cancer cells to enter a state of cellular senescence in which cells can secrete senescence-associated secretory phenotype (SASP) and produce small extracellular vesicles (sEVs) to interact with cells in the tumor microenvironment (TME). Tumor-derived sEVs that are taken up by recipient cells contribute to cancer cell metabolic plasticity, resistance to anticancer therapy, and adaptation to the TME. However, how radiation-induced sEVs support oral squamous cell carcinoma (OSCC) progression remains unclear.

METHODS

Beta-galactosidase staining and SASP mRNA expression analysis were used to evaluate the senescence-associated activity of OSCC cells after irradiation. Nanoparticle tracking analysis was performed to identify radiation-induced sEVs. Liquid chromatography-tandem mass spectrometry (LC-MS) was used to explore changes in the levels of proteins in radiation-induced sEVs. Cell Counting Kit-8 and colony formation assays were performed to investigate the function of radiation-induced SASP and sEVs in vitro. A xenograft tumor model was established to investigate the functions of radiation-induced sEVs and V-9302 in vivo as well as the underlying mechanisms. Bioinformatics analysis was performed to determine the relationship between glutamine metabolism and OSCC recurrence.

RESULTS

We determined that the radiation-induced SASP triggered OSCC cell proliferation. Additionally, radiation-induced sEVs exacerbated OSCC cell malignancy. LC-MS/MS and bioinformatics analyses revealed that SLC1A5, which is a cellular receptor that participates in glutamine uptake, was significantly enriched in radiation-induced sEVs. In vitro and in vivo, inhibiting SLC1A5 could block the oncogenic effects of radiation-induced sEVs in OSCC.

CONCLUSION

Radiation-induced sEVs might promote the proliferation of unirradiated cancer cells by enhancing glutamine metabolism; this might be a novel molecular mechanism underlying radiation resistance in OSCC patients.

Blue light irradiation suppresses oral squamous cell carcinoma through induction of endoplasmic reticulum stress and mitochondrial dysfunction

The therapeutic potential of blue light photobiomodulation in cancer treatment, particularly in inhibiting cell proliferation and promoting cell death, has attracted significant interest. Oral squamous cell carcinoma (OSCC) is a prevalent form of oral cancer, necessitating innovative treatment approaches to improve patient outcomes. In this study, we investigated the effects of 420 nm blue LED light on OSCC and explored the underlying mechanisms. Our results demonstrated that 420 nm blue light effectively reduced OSCC cell viability and migration, and induced G2/M arrest. Moreover, we observed that 420 nm blue light triggered endoplasmic reticulum (ER) stress and mitochondrial dysfunction in OSCC cells, leading to activation of the CHOP signal pathway and alterations in the levels of Bcl-2 and Bax proteins, ultimately promoting cell apoptosis. Additionally, blue light suppressed mitochondrial gene expression, likely due to its damage to mitochondrial DNA. This study highlights the distinct impact of 420 nm blue light on OSCC cells, providing valuable insights into its potential application as a clinical treatment for oral cancer.

Flap Reconstruction Results in Longer Overall Treatment Time in Patients Treated With Surgery and Adjuvant Radiotherapy for Carcinoma of the Oral Cavity and Larynx

OBJECTIVE

There is an inverse relationship between cancer cure and overall treatment time (OTT) in patients treated with surgical resection and radiotherapy (RT).

METHODS

OTT was evaluated based on the reconstruction procedure in 420 patients with oral cavity and larynx cancers treated with surgery and RT between 1991 and 2020.

RESULTS

With OTT >85 days, the difference between no versus yes flap reconstruction was ~20 percentage points and significant for all comparisons: primary closure (+/- skin graft), 49%, vs. rotation or free flap, 71% ( P <0.0001); primary closure (+/- skin graft), 49%, versus free flap without bone, 66% ( P =0.0358); and primary closure (+/- skin graft), 49%, versus free flap with bone, 82% ( P <0.0001).

CONCLUSIONS

The use of flap reconstructions results in substantial increases in OTT. Findings suggest a need to reevaluate current policies regarding the choice of reconstruction and starting RT sooner after surgery.

The incidence of osteoradionecrosis of the jaws in oral cavity cancer patients treated with intensity-modulated radiotherapy: a systematic review and meta-analysis

OBJECTIVE

A systematic review with meta-analysis was conducted to define the incidence of osteoradionecrosis (ORN) in patients with oral cavity cancer (OCC) treated with intensity-modulated radiotherapy (IMRT), and to identify the risk factors influencing its development.

STUDY DESIGN

Six databases were searched systematically. A meta-analysis was performed to determine overall, spontaneous, and dental extraction-attributed incidences of ORN. The Grading of Recommendations Assessment, Development, and Evaluation tool evaluated evidence certainty.

RESULTS

Out of 11 eligible studies, 6 underwent meta-analysis for the overall aggregated ORN incidence in OCC patients receiving IMRT, resulting in an incidence rate of 8% (95% CI: 6%-11%). Regarding development reasons, 2 studies were assessed, revealing an incidence of 36% (95% CI: 1%-98%) for spontaneous ORN, and 17% (95% CI: 5%-44%) ensued from dental extraction exclusively pre-RT. All rates had very low certainty of evidence. Factors significantly correlated with ORN development included postoperative RT use (78%), employment of therapeutic doses above 50 Gy, and mandibular involvement (80.5%).

CONCLUSION

The findings suggest that IMRT alone is not sufficient to decrease ORN rates in OCC patients, underscoring the importance of precisely identifying the involved risk factors. However, further detailed primary studies will be necessary.

The effect of treatment package time on locally advanced oral cavity cancer outcomes

OBJECTIVE(S)

To assess the influence of treatment package time (TPT) on overall survival (OS) and event free survival (EFS) in oral cavity cancer (OCC) patients treated with surgery and adjuvant radiation therapy (RT) with or without concurrent chemotherapy (CHT).

MATERIALS/METHODS

354 adult OCC patients treated at a single, high-volume center between 2012-2022 with various pathologic risk features were included. TPT was defined as days from surgery to RT completion. Kaplan-Meier estimates, log-rank p-values, univariable (UVA) and multivariable (MVA) Cox regression analyses were performed to determine the impact of TPT on OS and EFS, and the optimal TPT cutoff.

RESULTS

The optimal TPT cutoff was 105 days. TPT < 105 days was significantly associated with improved OS and EFS (p = 0.002 and p = 0.027, respectively) compared to TPT ≥ 105 days. On UVA, factors significantly associated with OS were TPT < 105 days, former/current smoker status, pathologic stage IV, positive perineural invasion (PNI), and extranodal extension (ENE) (all p < 0.05). On MVA for OS, TPT < 105 days, former/current smoker status, pathologic stage IV, and positive PNI (all p < 0.05) remained significant. Factors significantly associated with EFS on UVA were TPT < 105 days, former/current smoker status, pathologic stage IV, positive PNI or ENE, and concurrent CHT (all p < 0.05). On MVA, TPT < 105 days, pathologic stage IV, and positive PNI (all p < 0.05) remained significant.

CONCLUSIONS

In a large, homogenous cohort of OCCs, optimal TPT was <105 days, with TPT ≥ 105 days significantly associated with worse OS and EFS. Multidisciplinary coordination should analyze factors potentially contributing to treatment delay.

Are oral cancers effectively palliated with radiotherapy? Outcomes of treatment with a modified QUAD SHOT regimen

BACKGROUND

This study assessed a palliative radiotherapy regimen using daily radiation over 4 days for three courses in inoperable head and neck cancers, emphasizing oral primary cancers.

METHODS

Retrospective data of 116 patients treated with a daily dose of 3.6-3.7 Gy in four fractions over 4 days to a total of three courses, with a 2-week gap after every course, were analyzed for survival outcomes. A subgroup analysis was done for oral cancer.

RESULTS

Ninety-nine (85%) completed three courses. Overall subjective response rate was 77%. Median overall survival and progression-free survival were 12 months (95% confidence interval [CI]: 8-20) and 8 months (95% CI: 6-10), with numerically higher overall survival in oral cancer. The treatment was well tolerated, with no on-treatment hospitalization or grade 3-4 toxicities.

CONCLUSION

The modified QUAD SHOT regimen is practical for palliation in head and neck cancers.

Proposals for the delineation of neck clinical target volume for definitive Radiation therapy in patients with oral/ oropharyngeal squamous cell cancer based on lymph node distribution

PURPOSE/OBJECTIVE(S)

To establish the distribution pattern of cervical lymph node metastasis (LNM) and propose optimized clinical target volume (CTV) boundaries specific to oral/ oropharyngeal squamous cell cancer (OSCC/OPSCC).

MATERIALS/METHODS

531 patients with pathologically confirmed OSCC/OPSCC were enrolled from January 2013 to June 2022. Patients were stratified into two groups based on the minimal distance from the lesion's edge to the body's midline: ≤1 cm or > 1 cm. The geometric center of cervical metastatic LN was marked on a template CT. LN distribution probability maps were established. The relationships between the LN distribution and consensus guidelines were analyzed to propose modifications for CTV boundaries specific to OSCC/OPSCC.

RESULTS

A total of 1962 positive LNs were enrolled. Compared with the > 1 cm group, the ≤ 1 cm group has following feature tendencies: male smokers, younger, median organs, large gross lesion, infiltrative growth pattern, contralateral LNM. The most frequently involved level of LNM was ipsilateral II, but ipsilateral Ib had the highest involvement rate in the > 1 cm OSCC group. In addition, tongue cancer had a higher incidence of LN extranodal extension (ENE), which mainly distributes in ipsilateral level II. The skip metastasis was prone to from level III to Vb (3.5 %) in LN(+)/ENE (-), and level Ib to VIa (3.7 %) in LN(+)/ENE (+). Accordingly, we proposed the following modifications: 1. only including lateral and posterior margin of submandibular gland within 5 mm; 2. retracting posterior boundary of level II to front edge of levator scapula muscle, and descending the upper boundary to transverse process of C2 vertebra only for OSCC; 3. including posterior third of thyroglossal muscle or anterior edge of sternocleidomastoid muscle; 4. sparing level Va in case of only level II involvement; 5. including upper area of the thyroid cartilage plate in case of level Ib LN(+)/ENE (+); 6. sparing level VIIa is considered.

CONCLUSION

This is the first description of LN topographic spread patterns for OSCC/OPSCC. Modified CTV for prophylactic irradiation was proposed to spare the organs at risk and minimize adverse effects.

Combination of proton- or X-irradiation with anti-PDL1 immunotherapy in two murine oral cancers

Combining radiation therapy with immunotherapy is a strategy to improve both treatments. The purpose of this study was to compare responses for two syngeneic head and neck cancer (HNC) tumor models in mice following X-ray or proton irradiation with or without immune checkpoint inhibition (ICI). MOC1 (immunogenic) and MOC2 (less immunogenic) tumors were inoculated in the right hind leg of each mouse (C57BL/6J, n = 398). Mice were injected with anti-PDL1 (10 mg/kg, twice weekly for 2 weeks), and tumors were treated with single-dose irradiation (5-30 Gy) with X-rays or protons. MOC2 tumors grew faster and were more radioresistant than MOC1 tumors, and all mice with MOC2 tumors developed metastases. Irradiation reduced the tumor volume in a dose-dependent manner. ICI alone reduced the tumor volume for MOC1 with 20% compared to controls, while no reduction was seen for MOC2. For MOC1, there was a clear treatment synergy when combining irradiation with ICI for radiation doses above 5 Gy and there was a tendency for X-rays being slightly more biologically effective compared to protons. For MOC2, there was a tendency of protons being more effective than X-rays, but both radiation types showed a small synergy when combined with ICI. Although the responses and magnitudes of the therapeutic effect varied, the optimal radiation dose for maximal synergy appeared to be in the order of 10-15 Gy, regardless of tumor model.

Can interventional radiotherapy (brachytherapy) be an alternative to surgery in early-stage oral cavity cancer? A systematic review

PURPOSE

Brachytherapy (BT), also known as interventional radiotherapy (IRT), has proven its utility in the treatment of localized tumors. The aim of this review was to examine the efficacy of modern BT in early-stage oral cavity cancer (OCC) in terms of local control (LC), overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and safety.

METHODS

The SPIDER framework was used, with sample (S), phenomena of interest (PI), design (D), evaluation (E), and research type (R) corresponding to early-stage oral cavity cancer (S); BT (PI); named types of qualitative data collection and analysis (D); LC, OS, DFS, CSS, and toxicity (E); qualitative method (R). Systematic research using PubMed and Scopus was performed to identify full articles evaluating the efficacy of BT in patients with early-stage OCC. The studies were identified using medical subject headings (MeSH). We also performed a PubMed search with the keywords "brachytherapy oral cavity cancer, surgery." The search was restricted to the English language. The timeframe 2002-2022 as year of publication was considered. We analyzed clinical studies of patients with OCC treated with BT alone only as full text; conference papers, surveys, letters, editorials, book chapters, and reviews were excluded.

RESULTS

The literature search resulted in 517 articles. After the selection process, 7 studies fulfilled the inclusion criteria and were included in this review, totaling 456 patients with early-stage node-negative OCC who were treated with BT alone (304 patients). Five-year LC, DFS, and OS for the BT group were 60-100%, 82-91%, and 50-84%, respectively.

CONCLUSION

In conclusion, our review suggests that BT is effective in the treatment of early-stage OCC, particularly for T1N0 of the lip, mobile tongue, and buccal mucosa cancers, with good functional and toxicity profiles.

Astaxanthin Synergizes with Ionizing Radiation (IR) in Oral Squamous Cell Carcinoma (OSCC)

Astaxanthin (ATX) is known for its antioxidant and anti-inflammation functions yet its role in cancers requires more research. This study is aimed to reveal the potential synergetic effect of ATX with ionizing radiation (IR) in OSCC. Cell survival was measured after human OSCC cells including CAL27 and SCC9, and normal human oral keratinocytes (NHOKs) were treated with different concentrations of ATX for 24 h. Colony formation assays were performed after OSCC cells were treated with IR, ATX (20 μ M), or combined and survival fraction was analyzed. Malondialdehyde (MDA), glutathione (GSH), and intercellular iron levels were measured. Western blot method was used to measure the ferroptosis-related proteins, GPX4, SLC7A11, and ACSL4. In xenograft mice model, we evaluated the tumor volumes, tumor growth, and examined the GPX4/ACSL4 proteins in tumor tissues using Immunohistochemistry (IHC). ATX inhibited viability of OSCC cells but not NHOK. In OSCC cells, ATX further enhanced the cell death induced by IR. In addition, ATX promoted the MDA content, Iron levels but inhibited the GSH regulated by IR in cells. ATX could synergize with IR, further inhibiting GPX4, SLC7A11 and promoting ACSL4 in OSCC cells. In vivo, ATX and IR treatment inhibited OSCC tumor growth and the group with combined treatment showed the most inhibitory effect. GPX4 was inhibited by IR and further inhibited in the combined group while ACSL4 was promoted by IR and enhanced more significantly in the combined group. ATX might synergize with IR treatment in OSCC partly via ferroptosis.

Adjuvant Radiotherapy in Moderately Advanced (T3) Oral Cavity Cancers

OBJECTIVE

To investigate the impact of adjuvant radiotherapy in isolated locally advanced oral cavity cancers (pT3N0M0) without adverse features.

METHODS

We selected all patients from the National Cancer Database (2004-2019) who underwent surgical treatment where the final pathology was T3N0M0 with negative margins. Demographics, details of treatment, and outcomes were abstracted. The impact of radiotherapy on survival was assessed with univariable, multivariable, and propensity score-matched analyses.

RESULTS

We identified 571 patients in our survival cohort. Most were male (348, 60.9%), and median age was 65. Less than one-third (176, 30.8%) received adjuvant radiotherapy. The median length of follow-up was 29 months. Overall, adjuvant radiotherapy was associated with improved survival (87.2% vs. 77.7%, at 2 years, p < 0.01). On multivariable analysis controlling for age and comorbidities, this survival difference persisted (HR: 0.62, 95% CI: 0.43-0.90, p = 0.01). In a propensity score-matched population of 278 patients matched on age and comorbidities, adjuvant radiotherapy was still associated with longer survival (87.4% vs. 78.5%, p = 0.014).

CONCLUSION

In our study, adjuvant radiotherapy was associated with improved survival in completely excised locally advanced oral cavity tumors (T3N0M0). However, a significant proportion of patients do not receive adjuvant radiotherapy. These findings highlight the need for continued efforts to promote guideline-recommended care.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:2236-2242, 2024.

Impact of Adjuvant Radiotherapy in Squamous Cell Carcinoma of the Oral Cavity with Perineural Invasion

OBJECTIVE

Current guidelines indicate postoperative radiotherapy (PORT) in oral squamous cell carcinoma (OSCC) with perineural invasion (PNI), however, its real benefit has never been proven. The aim of our study is to investigate the benefit of PORT in OSCC patients with PNI in terms of survival and disease control.

DATA SOURCES

The Pubmed/MEDLINE, Cochrane Library, and Scopus databases.

REVIEW METHODS

Patients with PNI + OSCC treated with primary surgery were extracted from the included studies. The pooled logHR was calculated by comparing patients who underwent PORT to those who underwent only observation for overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), and locoregional control (LRC).

RESULTS

About 690 patients with primary OSCC and PNI were included from nine studies. 374 (54.2%) patients underwent PORT, while 316 (45.8%) underwent observation. Analyses showed non-significant difference between the two groups for OS (HR: 1.01; 95% CI: 0.38-2.69), DSS (HR: 2.03; 95% CI: 0.54-7.56), and LRC (HR: 0.89; 95% CI: 0.53-1.50). They showed a significant difference in terms of DFS (HR: 0.86; 95% CI: 0.77-0.97).

CONCLUSION

The real benefit of PORT in OSCC patients with PNI is still unclear, although it may have a positive impact on DFS. Clinicians should consider individual patient's characteristics, tumor factors, and treatment goals when deciding whether to recommend PORT. Further studies are needed to clarify which entity of PNI really benefits from PORT.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2019-2027, 2024.

Radiotherapy upregulated immune checkpoints contribute to the development of second primary OSCC

OBJECTIVES

Radiation injury is common after radiotherapy for head and neck cancer. Radiotherapy can reshape the immune microenvironment and cause immunosuppression, including dysregulation of immune checkpoints (ICs). However, the relationship between oral ICs expression after radiation and the development of second primary tumors is unclear.

METHODS

Clinical specimens of second primary oral squamous cell carcinoma after radiotherapy (s-OSCC) and primary OSCC (p-OSCC) were collected. The expression and prognostic value of PD-1, VISTA, and TIM-3 were analyzed using immunohistochemistry. To further clarify the relationship between radiation and ICs alteration, a rat model was constructed to explore the spatiotemporal changes of ICs in the oral mucosa after radiation.

RESULTS

In carcinoma tissue, the expression of TIM-3 was higher in s-OSCC than in p-OSCC, while the expression of PD-1 and VISTA was similar between the groups. In para-carcinoma tissue, the expression of PD-1, VISTA, and TIM-3 was higher in s-OSCC. High ICs expression was associated with poor survival. In the rat model, ICs were locally upregulated in the irradiated tongue. Moreover, there was a bystander effect, in which the ICs were also upregulated in the unirradiated site.

CONCLUSION

Radiation may upregulate ICs expression in oral mucosa and contribute to the development of s-OSCC.

Clinical outcomes and failure patterns after postoperative radiotherapy for oral cavity squamous cell carcinoma

PURPOSE

This study aimed to assess recurrence patterns and identify the optimal dose and target volumes of postoperative radiotherapy (PORT) in patients with oral cavity squamous cell carcinoma (OSCC).

METHODS

Data of 111 patients who received PORT for OSCC between January 2010 and April 2020 were retrospectively reviewed. The median age was 68 years (range 19-88). PORT was administered as initial treatment to 63 patients and as salvage treatment for recurrent tumors to 48 patients. The median prescribed dose was 60 Gy (range 50-66) administered in 30 fractions (range 25-33).

RESULTS

Median follow-up time was 73 months (range 24-147). Overall survival (OS), progression-free survival (PFS), local control (LC), and locoregional control (LRC) at 3 years were 55.6%, 45.6%, 74.6%, and 63.1%, respectively. There were no significant differences in OS, PFS, LC, and LRC between the initially diagnosed and postoperative recurrent cases. Of 22 patients (20%) who developed regional nodal recurrences, 17 (15%) and 11 (10%) had in-field and out-of-field recurrences, respectively. Of 105 patients who received irradiation to the primary tumor bed, 24 (23%) developed recurrence at the primary site. The PFS and LC rates were significantly worse in patients receiving ≤ 56 Gy to the primary site than those receiving > 56 Gy (p = 0.016 and p = 0.032, respectively).

CONCLUSION

PORT was effective for postoperative recurrences as well as for initially diagnosed oral cavity cancer. Doses greater than 56 Gy to the primary site may be required in PORT for OSCC.

Comparison of a daily and alternate-day photobiomodulation protocol in the prevention of oral mucositis in patients undergoing radiochemotherapy for oral cancer: a triple-blind, controlled clinical trial

BACKGROUND

Preventive Photobiomodulation Therapy (PBMT) significantly reduces oral mucositis (OM) severity in patients undergoing Radiochemotherapy (RCT) for the treatment of oral cancer, but daily applications generate cost, overload the dental team, and reduce the number of patients assisted.To evaluate the effectiveness of two PBMT protocols in preventing OM in patients undergoing RCT for oral cancer.

MATERIAL AND METHODS

16 patients diagnosed with oral cancer undergoing RCT were included, equally divided into two groups: a group treated daily with PBMT, and another group also submitted to daily treatment, however, performing the application of PBMT every three days, interspersed with a simulation of PBMT (placebo). A red laser was used (~660 nm), 0.1W power, 1J of energy applied per point, 9 points per area (labial mucosa, buccal mucosa, lateral borders of the tongue, body of the tongue, and floor of the mouth) from the beginning of RCT until the end of the oncological treatment. Daily assessments were performed regarding OM scores, the World Health Organization (WHO) pain scale, and the visual analog scale (VAS). Weight, salivary flow (SGAPP), OHIP-14, and DMFT were evaluated on the initial and final days of RT. OM incidence and clinical data were compared by Pearson's chi-square test or Fisher's exact test. Pain and other scale scores were compared using the Mann-Whitney and Friedman/Dunn tests (SPSS v20.0 p<0.05).

RESULTS

In the group with PBMT on alternate days, there was an increase in the frequency of grade 2 and grade 3 oral mucositis and an increased risk of grade 2 oral mucositis, in addition to higher mean pain scores and greater reduction in salivary flow.

CONCLUSIONS

The daily PBMT protocol proved more effective in controlling the frequency and severity of OM, pain, and salivary flow.

Comparing the clinical outcomes of initial surgery and primary definitive radiotherapy with a dosage of 6600 cGy or higher in cT1-2N0M0 oral cavity squamous cell carcinoma: A nationwide cohort study

BACKGROUND

To compare the clinical outcomes of two treatment modalities, initial surgery and primary definitive radiotherapy (RT), in Taiwanese patients diagnosed with cT1-2N0M0 oral cavity squamous cell carcinoma (OCSCC).

METHODS

Between 2011 and 2019, we analyzed data for 13,542 cT1-2N0M0 patients who underwent initial surgery (n = 13,542) or definitive RT with a dosage of at least 6600 cGy (n = 145) for the treatment of OCSCC. To account for baseline differences, we employed propensity score (PS) matching, resulting in two well-balanced study groups (initial surgery, n = 580; definitive RT, n = 145).

RESULTS

Before PS matching, the 5-year disease-specific survival (DSS) rates were 88% for the surgery group and 58% for the RT group. After PS matching, the 5-year DSS rates of the two groups were 86% and 58%, respectively. Similarly, the 5-year overall survival (OS) rates before PS matching were 80% for the surgery group and 36% for the RT group, whereas after PS matching, they were 73% and 36%, respectively. All these differences were statistically significant (p < 0.0001). A multivariable analysis identified treatment with RT, older age, stage II tumors, and a higher burden of comorbidities as independent risk factors for both DSS and OS. We also examined the 5-year outcomes for various subgroups (margin ≥5 mm, margin <5 mm, positive margins, RT combined with chemotherapy, and RT alone) as follows: DSS, 89%/88%/79%/63%/51%, respectively, p < 0.0001; OS, 82%/79%/68%/39%/32%, respectively, p < 0.0001.

CONCLUSIONS

In Taiwanese patients with cT1-2N0M0 OCSCC, a remarkably low proportion (1.1%) completed definitive RT. A significant survival disparity of 30% was observed between patients who underwent initial surgery and those who received definitive RT. Interestingly, even patients from the surgical group with positive surgical margins exhibited a significantly superior survival compared to those in the definitive RT group.