A multicenter retrospective investigation on the efficacy of perioperative oral management in cancer patients.

Patients develop a number of oral complications during cancer treatments. Oral bacteria are associated with the onset of dental focal infections and the progression of oral mucositis. Dental focal infections are frequently associated with the systemic onset of bacteremia, sepsis, and pneumonia. The degeneration of oral function with these complications may become an obstacle to cancer treatments. Although comprehensive oral management, including oral care, the removal of dental focal infections, and improvements in oral function with dentures, is conducted for cancer patients in Japan, few studies have assessed its efficacy.The aim of the present study was to investigate the incidence of dental/oral complications in cancer patients with perioperative oral managements (POMs) based on a large number of case series with a multicenter retrospective analysis.The medical records of cancer patients with POMs were retrospectively reviewed and the incidence of oral complications and efficacy of oral management were investigated.A total of 2744 cancer patients with POMs (1684 males and 1080 females, mean age 65.9 ±â€Š13.0 years) were included and investigated in the present study. Among these patients, 2097 (76.4%) started POM before the initiation of cancer treatments, with 2130 (77.6%) receiving oral care only and 391 (14.2%) being subjected to invasive treatments, such as tooth extraction. The incidence of dental focal infections during the period of cancer treatments was 8.2%. The most frequent infection was acute periodontitis, including alveolar abscesses (112 patients, 4.1%). The incidence of grade 2 and 3 oral mucositis was 2.8%. Prolonged fever was observed in 113 patients (4.1%), with 7 having dental focal infections (6.2%). These incidence rates were lower than those reported previously.Based on analyses of a large number of patients, the present results support the efficacy of oral management in cancer patients. However, further studies are needed to establish adequate oral management guidelines for cancer patients.

Factors associated with severe oral mucositis and candidiasis in patients undergoing radiotherapy for oral and oropharyngeal carcinomas: a retrospective multicenter study of 326 patients.

PURPOSE: The present retrospective multicenter study intended to investigate the factors associated with severe oral mucositis and candidiasis in patients undergoing radiotherapy for oral and oropharyngeal carcinomas. METHODS: A total of 326 patients who underwent radiotherapy for oral and oropharyngeal cancers were enrolled in the study. The patients' age, sex, body mass index, primary site, diabetes, serum albumin, creatinine, hemoglobin, leukocyte and lymphocyte, concurrent cisplatin or cetuximab, method of radiation, total radiation dose, feeding route, use of spacers, pilocarpine hydrochloride, and corticosteroid ointment were examined, and the associations of each variable with oral mucositis and candidiasis were analyzed by multivariate Cox regression analysis. RESULTS: Grade 3 oral mucositis occurred in 136 (41.7%) patients. Male sex, oropharyngeal cancer, low hemoglobin levels, low leukocytes or lymphocytes, concurrent cisplatin or cetuximab, and oral feeding were found to be significantly associated with a higher incidence of severe oral mucositis. Oral candidiasis occurred in 101 (31.0%) patients. Oropharyngeal cancer, low leukocyte count, and oral mucositis of grade 2 or higher were found to be significantly associated with a higher incidence of oral candidiasis. The use of a topical steroid ointment was not found to be a risk factor for oral candidiasis. CONCLUSIONS: The present retrospective study demonstrated that certain factors may predispose patients with oral and oropharyngeal cancers receiving radiotherapy to develop severe oral mucositis and oral candidiasis. A preventive strategy for severe oral mucositis needs to be established in the future for high-risk cases.

Drug holiday clinical relevance verification for antiresorptive agents in medication-related osteonecrosis cases of the jaw.

Treatment strategies of medication-related osteonecrosis of the jaw (MRONJ) are controversial. Recently, surgical treatment has been reported as superior to nonsurgical treatment, but the contribution discontinued antiresorptive agent use during MRONJ treatment remains unclear. This study aimed to evaluate the efficacy of drug holidays and treatment strategies in MRONJ cases. Four-hundred and twenty-seven patients with MRONJ treated at nine hospitals from 2009 to 2017 were included in this multicenter retrospective study. Multivariate Cox regression analysis showed that the primary disease (osteoporosis or malignant tumor), diabetes, serum albumin, and treatment method (surgical or nonsurgical) were significantly correlated with the cure rate. The cumulative 1-year cure rates in the surgical and nonsurgical treatment groups were 64.7% and 18.2%, respectively. However, discontinuing antiresorptive agents did not influence the treatment outcome in the cohort overall, or in 230 patients after performing propensity score matching among the discontinuation and continuation groups. When stratifying by treatment method, antiresorptive agent discontinuation significantly increased the cure rate in patients with osteoporosis who underwent nonsurgical treatment. In patients with malignant tumors undergoing nonsurgical therapy, discontinuing the antiresorptive agent was associated with a better treatment outcome, but not with statistical significance. In contrast, drug holidays showed no effect on improving outcomes in patients with both osteoporosis and malignant tumors who underwent surgical therapy. Thus, regardless of the primary disease, discontinuing antiresorptive agents during treatment for MRONJ may not be necessary and may be helpful in some cases. Future prospective trials should examine this question further.

Red LED Light Is Influenced by IL-6 to Promote the Migration Ability of Oral Squamous Cell Carcinoma Cell Line.

AIM: The purpose of this study was to search for the influence of red LED light of oral squamous cell carcinoma cells (OSCC) Material & Methods: HSC-3 was irradiated with red LED light (630 nm/3 J). Proliferative capacity was analyzed using WST-1. Transwell migration assay, real-time PCR, and ELISA method were also used to analyze migratory ability. CONCLUSIONS: HSC-3 cells irradiated with red LED light showed increased migration ability. Interestingly, we clarified that the expression of Interleukin-6 (IL-6), which promotes the migratory ability of cancer cells, is induced.

Effect of low-intensity pulsed ultrasound after intraoral vertical ramus osteotomy.

OBJECTIVE: The present study investigated the effect of low-intensity pulsed ultrasound (LIPUS) on long-term osseous healing of the cleavage space between bone fragments after intraoral vertical ramus osteotomy (IVRO). STUDY DESIGN: Patients undergoing IVRO were randomly assigned to the LIPUS group (n = 12) or the control group (n = 9) after surgery. LIPUS treatments were applied daily to the cleavage space between bone fragments for 3 weeks. We observed 3-dimensional quantitative color mapping of the whole mandible created by computed tomography (CT) data at 1 month, 6 months, and 1 year postoperatively. On the basis of CT values, the color grades were classified as D1 to D5 by using the Misch criteria. We then calculated mean CT values and rated each color grade in different selection ranges. RESULTS: The mean CT values of the LIPUS group were significantly higher than those of the control group at 1 month, 6 months and 1 year postoperatively (P < .01). The color grades of the cleavage between bone fragments increased from D5 to D1 over time. CONCLUSIONS: Our results indicated that LIPUS promoted osseous healing after IVRO, thus improving bone density and offering clinical benefits.

Dental intervention against osteoradionecrosis of the jaws in irradiated patients with head and neck malignancy: a single-arm prospective study.

BACKGROUND: The purpose of this study was to investigate the effectiveness of dental intervention before and after radiation therapy (RT) for head and neck malignancy on prevention of osteoradionecrosis (ORN) of the jaws. METHODS: This is a single-arm prospective study according to intervention protocol of prophylactic dental extraction before RT and routine follow-up after RT. The primary endpoint was the occurrence of jawbone exposure during the first 2 years after RT. RESULTS: Sixty-seven patients were assessed. Before RT, 144 teeth among 39 patients (58%) were prophylactically extracted. The occurrence of transient jawbone exposure during the first 2 years after RT was 7%. Because those jawbone exposures healed with intervention after RT, no jawbone exposure was found at 2 years after RT. CONCLUSIONS: Dental intervention both before and after RT seemed to be important to prevent ORN development. Further studies in larger cohorts are necessary.

Clinical Evaluation of CO2 Laser Vaporization Therapy for Oral Lichen Planus: A Single-Arm Intervention Study.

Objective: The purpose of this study is to evaluate the efficacy of CO2 laser vaporization therapy for oral lichen planus (OLP) refractory to conservative treatments. Methods: The study group comprised 16 patients with clinically and histologically diagnosed OLP. They underwent conservative treatment for 3 months using an adrenal cortex hormone ointment and azulene sulfonate sodium hydrate gargle. Patients who showed no improvement with conservative treatment underwent CO2 laser vaporization therapy (3 W, continuous-wave mode). The assessment was performed using the numerical rating scale (NRS) as a subjective indicator and the Thongprasom sign score (TSS) as an objective indicator of OLP. These two scales were recorded during examinations performed before treatment and then at 7 days, 1, 3, and 6 months, and 1 year after irradiation. Differences between preirradiation and each point of time after irradiation were tested by Wilcoxon's signed-rank tests. Results: Laser irradiation was administered to 9 patients with 11 sites. The NRS score and TSS decreased at all 11 sites (100%) and 10 sites (90.9%) at 1 year after irradiation compared with preirradiation scores. The NRS score and TSS were statistically lower (p < 0.05) at 1 and 3 months (short-term) and 6 months and 1 year (mid-long-term) after irradiation than the preirradiation scores. There were no patients with malignant transformation during the study period. Conclusions: These single-arm clinical trial results show the efficacy of CO2 laser vaporization therapy for OLP refractory to conservative treatment.

A radiologic evaluation of the incidence and morphology of maxillary sinus septa in Japanese dentate maxillae.

PURPOSE: Evaluation of the inner aspect of the maxillary sinus is important for the success of a sinus lift procedure. The most common surgical complication is perforation of the Schneiderian membrane, which is thought to occur because of the presence of maxillary sinus septa. Therefore, we retrospectively investigated the incidence and morphology of maxillary sinus septa using multiplanar reformatted computed tomographic (CT) images from dentate Japanese patients. METHODS: A total of 276 patients and 552 maxillary sinus segments were evaluated. The maxillary sinus septa were divided into four locations: forefront, anterior, middle, and posterior. The heights of the septa were measured at three sites from the deepest point of the sinus floor: lateral, mid-point, and medial. RESULTS: Sinus septa were identified in 191 of 552 (34.6%) maxillary sinus segments obtained from 111 of 276 (40.2%) patients. One unilateral septum was most commonly detected, and the sinus septa were most often located in the middle of the maxillary sinus. The average height of the identified septa was 8.69 ± 4.68 mm (mean ± standard deviation). CONCLUSION: Multiplanar reformatted CT images can identify maxillary sinus septa in any plane. The height of maxillary sinus septa in the dentate maxillae was higher than detected in previous studies. Appropriate treatment planning using CT images should be considered to prevent surgical complications.

Effect of size difference between hemiglossectomy and reconstruction flap on oral functions: A retrospective cohort study.

BACKGROUND AND OBJECTIVE: Forearm free flaps are used after hemiglossectomy. However, no investigation has been performed on whether oral functions are better preserved when sizes of the resection and reconstruction flap are exact matches, or whether the size of the resection should be changed. We aimed to retrospectively examine whether size differences between the resection and reconstruction flap affect speech and swallowing functions postoperatively, and to determine whether there are more favorable flap size ratios. METHODS: This is a retrospective cohort study of patients undergoing hemiglossectomy using a forearm free flap between 2006 and 2016 at Kobe University Hospital, Japan. The effect of size difference between the resection and reconstruction flap on maintained oral function was assessed. Speech and swallowing functions were assessed, and their correlation with the ratio of the flap size to that of the resected area was determined. With these data, distribution maps of the relationship between the functional level and reconstructed dimension ratio were prepared. The more suitable reconstructed dimension ratio was examined and evaluated. The Fisher exact test, Kruskal-Wallis test, and Scheffe test were used in statistical analyses. RESULTS: Eighty-eight patients underwent hemiglossectomy using a forearm free flap during a 10-year period. Of these cases, 66 patients were included in this study, while 22 were excluded. The ratio of the area of the reconstruction flap to that of the resection site was 0.59-2.79 (median: 1.61). Sixty patients had flaps greater than the resection area, whereas 6 had smaller flaps. Significant differences were found in speech intelligibility and swallowing function when the reconstructed dimension ratio was categorized as follows: ≤1.3, 1.3-1.8, and ≥1.8. CONCLUSION: Our findings suggest that postoperative deterioration of oral functions after hemiglossectomy could be reduced if reconstruction is performed using a forearm free flap with a surface area 1.3 to 1.8 times greater than that of the resection area.

Induced Pluripotent Stem Cell-related Genes Correlate With Poor Prognoses of Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: We recently investigated the contribution of the iPS-related genes SOX2, OCT4, and Nanog to de-differentiation by assaying for their mRNA levels. Given that mRNA expression does not always correlate with the protein levels, the aim of this study was to retrospectively determine the expression of these four iPS-related factors in human OSCC specimens by immunohistochemistry and examine their association with patient prognosis. MATERIALS AND METHODS: iPS cell-related gene expression in 89 OSCC patients by tissue microarray, and its correlation with clinicopathological factors, differentiation, metastasis, and poor prognoses were investigated. RESULTS: No evidence of statistically significant relationships was found between the expression of iPS cell-related genes and clinicopathological parameters. However, our data indicated that KLF4 expression was associated with survival, and poor tumor differentiation. In addition, high expression of KLF4 was an independent poor prognostic factor (p=0.004) for OSCC patients. CONCLUSION: In preoperative biopsies, higher KLF4 and poor differentiation may be clinically effective predictors for the prognosis of oral cancer.

Effects of perioperative oral care on prevention of postoperative pneumonia after lung resection: Multicenter retrospective study with propensity score matching analysis.

BACKGROUND: Postoperative pneumonia can be a fatal complication that may occur after lung resection in cancer patients. Some reports have shown that the incidence of postoperative pneumonia is decreased after esophageal surgery by perioperative oral care; however, there exist no data to suggest that a lack of perioperative oral care can be a risk factor for postoperative pneumonia after lung resection. To investigate the association between the preventive effect of oral care and postoperative pneumonia, we conducted a multicenter, retrospective study of lung cancer patients who underwent lung resection. METHODS: Between January 2014 and December 2016, a total of 721 patients underwent lung resections at 1 of the 6 hospitals included in our study. Among 721 patients, 280 (38.8%) received perioperative oral care, and the remaining 441 (61.2%) did not receive any such care. Propensity score matching was performed to minimize selection biases associated with the comparison of retrospective data between the oral care and control groups. RESULTS: Of the 721 patients, 54 (7.5%) experienced postoperative pneumonia involving 13 of the 280 patients (4.6%) in the oral care group and 41 of the 441 patients (9.3%) in the control group (P = .02). On propensity score analysis, a significant difference was also found between oral care intervention and incidence of postoperative pneumonia (P = .002). CONCLUSION: Our results suggest that perioperative oral care is an effective method to decrease the occurrence of postoperative pneumonia in patients who have undergone lung resection.

Multicenter retrospective study of the prognosis and treatment outcomes of Japanese oral squamous cell carcinoma patients with level IV/V metastasis.

BACKGROUND: The purpose of this study was to retrospectively describe the characteristics and outcomes of patients with oral squamous cell carcinoma and level IV/V metastasis and to compare patients who underwent no postoperative therapy with those who underwent postoperative radiotherapy (RT) and concomitant chemoradiotherapy (CCRT). METHODS: We evaluated 669 patients. Clinicopathological data, postoperative therapy, and clinical course were investigated. RESULTS: Sixty-one patients (9.1%) developed level IV/V metastasis. The 3-year cumulative overall survival rates of patients with and without level IV/V metastasis were 47.3% and 64.3%, respectively. Tongue tumors, pN2 or N3 classification, and moderate or poor differentiation were significantly associated with the development of level IV/V metastasis. The surgery+RT/CCRT group was associated with better 3-year cumulative disease-specific survival and overall survival rates than the surgery only group. CONCLUSION: Adjuvant therapy (RT alone or CCRT) after surgery is recommended for patients with level IV/V metastasis.

CD163+ macrophages infiltration correlates with the immunosuppressive cytokine interleukin 10 expression in tongue leukoplakia.

Objective: Accumulating evidence suggests that macrophages are involved in the immunoediting of oral squamous cell carcinoma but the role of macrophages in oral carcinogenesis is unclear. We aimed to clarify the role of macrophages in oral leukoplakia, which is the most common oral potentially malignant disorder from immunotolerance viewpoint. Materials and methods: The study included 24 patients who underwent surgical resection for tongue leukoplakia. The relationships between macrophage markers and clinicopathological factors were assessed. Conditioned medium was harvested from the CD163+ human monocytic leukaemia cell line, THP-1. The phenotypic alteration of human oral keratinocytes by the conditioned medium treatment was assessed using quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Moreover, the clinical samples were evaluated using immunohistochemistry. Results: Tongue leukoplakia tissues with high CD163+ macrophage infiltration were associated with significantly higher degrees of epithelial dysplasia, abnormal Ki-67 expression and cytokeratin13 loss when compared with the tissues with low CD163+ macrophage infiltration. In vitro, CD163+ THP-1 conditioned medium induced immunosuppressive molecules, especially interleukin-10 (IL-10) in human oral keratinocytes. The IL-10 expression levels showed significant positive correlations with not only the numbers of FOXP3+ regulatory T cells but also that of CD163+ macrophages. Conclusions: In tongue leukoplakia, CD163+ macrophages infiltration correlates with immunosuppressive cytokine IL-10 expression.

Tumor budding and adjacent tissue at the invasive front correlate with delayed neck metastasis in clinical early-stage tongue squamous cell carcinoma.

BACKGROUND AND OBJECTIVES: Some patients with early-stage oral cancer have a poor prognosis owing to the delayed neck metastasis (DNM). Tumor budding is reportedly a promising prognostic marker in many cancers. Moreover, the tissue surrounding a tumor is also considered to play a prognostic role. In this study, we evaluated whether tumor budding and adjacent tissue at the invasive front can be potential novel predictors of DNM in early tongue cancer. METHODS: In total, 337 patients with early-stage tongue squamous cell carcinoma were retrospectively reviewed. The patient characteristics and histopathological factors were evaluated for association with DNM. DNM rates were calculated; items which were significant in the univariate analysis were used as explanatory variables, and independent factors for DNM were identified by the multivariate analysis. RESULTS: The univariate analysis identified T classification, depth of invasion, tumor budding, vascular invasion, and adjacent tissue at the invasive front as significant predictors of DNM; the multivariate analysis using these factors revealed all the above variables except vascular invasion, which are independent predictors of DNM. CONCLUSION: In addition to conventional predictors, high grade tumor budding and adjacent tissue at the invasive front can serve as useful predictors of DNM in early tongue cancer.

A Multicenter Retrospective Study of Elective Neck Dissection for T1-2N0M0 Tongue Squamous Cell Carcinoma: Analysis Using Propensity Score-Matching.

BACKGROUND: This multicenter retrospective study aimed to determine whether elective neck dissection (END) can be performed for T1-2N0M0 tongue cancer. METHODS: Patients with T1-2N0M0 tongue squamous cell carcinoma who received treatment between January 2000 and December 2012 were enrolled at 14 multicenter study sites. The 5-year overall survival (OS) and 5-year disease-specific survival (DSS) were compared between the propensity score-matched END and observation (OBS) groups. RESULTS: The results showed that the OS rates among the 1234 enrolled patients were 85.5% in the END group and 90.2% in the OBS group (P = 0.182). The DSS rates were 87.0% in the END group and 94.3% in the OBS group (P = 0.003). Among the matched patients, the OS rates were 87.1% in the END group and 76.2% in the OBS group (P = 0.0051), and the respective DSS rates were 89.2% and 82.2% (P = 0.0335). CONCLUSION: This study showed that END is beneficial for T1-2N0M0 tongue cancer. However, END should be performed for patients with a tumor depth of 4-5 mm or more, which is the depth associated with a high rate of lymph node metastasis. The use of END should be carefully considered for both elderly and young patients.

Long-Term Effects on Volume Change in Musculocutaneous Flaps after Head and Neck Reconstruction.

OBJECTIVE: Musculocutaneous flap reconstruction surgery is one of the standard procedures following head and neck cancer resection. However, no previous studies have classified flaps in terms of muscle and fat or examined them after long-term follow-up. The purpose of this study was to estimate the fat and muscle volume changes in musculocutaneous flaps during long-term follow-up. METHODS: We conducted a retrospective analysis of 35 patients after musculocutaneous flap reconstruction. The total, fat, and muscle volumes of the musculocutaneous flaps were measured using 3-dimensional images. Changes in flap volumes over time (1 month, 1 year [POY1], and 5 years [POY5] postoperatively) were assessed. Flap persistence was calculated using flap volumes at 1 month after reconstruction for reference. RESULTS: Flap persistence at POY5 was 42.0% in total, 64.1% in fat, and 25.4% in muscle. Muscle persistence was significantly decreased (p < 0.0001). In a multiple regression analysis, decreased body mass index (BMI) of ≥ 5% influenced fat persistence less than muscle persistence at POY1; however, there was no significant difference at POY5. Postoperative radiation therapy was associated with a significant decrease in total flap persistence at POY1 (p = 0.046) and POY5 (p = 0.0097). Muscle persistence significantly decreased at POY5 (p = 0.0108). Age significantly influenced muscle volume at POY1 (p = 0.0072). CONCLUSION: Reconstruction flaps are well-preserved with high fat-to-muscle ratios. Recommendations for weight maintenance are necessary for patients less than 2 years after surgery due to the influence of BMI on fat persistence. Radiation therapy is necessary for some patients based on their disease state. Intensity-modulated radiation therapy can be offered to reduce scattering irradiation to normal tissues.

Perioperative intervention by oral medicine team in cardiovascular surgery patients.

In brief, perioperative oral intervention consists of elimination of odontogenic foci and maintenance of oral hygiene in patients undergoing surgery. The importance of oral intervention before, during, and after medical treatments is well-known, especially in cancer patients, because odontogenic foci such as untreated deep dental caries or periodontitis can cause systemic infection in patients with myelosuppression resulting from chemotherapy. Although perioperative oral intervention is currently recommended for patients with cardiovascular disease, its efficacy in this population has not been established. This article consists of three sections: first, we review the current knowledge about the association between dental disease and cardiovascular disease to show the importance of oral hygiene maintenance and the risks of invasive dental procedures in patients with cardiovascular disease; second, we introduce pertinent, but limited evidence concerning the effect of oral care in preventing postoperative pneumonia; and finally, we present the optimal strategy for perioperative oral intervention in cardiovascular surgery patients.

Lymphangiogenesis and Lymph Node Metastasis in Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: Tumor lymphangiogenesis plays a key role in lymph node (LN) metastasis in oral squamous cell carcinoma (OSCC). The purpose of this study was to investigate podoplanin and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and their relationship to nodal metastasis and other clinicopathological variables. PATIENTS AND METHODS: Podoplanin and LYVE-1 expression of the primary tumor and normal tissue were investigated by means of a quantitative real-time PCR assay and immunohistochemistry in samples from 33 cases of OSCC. RESULTS: The mRNA high expression levels of both genes had a statistically significantly higher rate of LN metastasis (p<0.01) and histological grade (p<0.01 for podoplanin, p<0.05 for LYVE-1). High expression of each gene, as shown by immunohistochemistry, had a statistically significant higher rate of LN metastasis (p<0.01 for podoplanin, p<0.05 for LYVE-1). CONCLUSION: Podoplanin and LYVE-1 were strongly associated with LN metastasis.

A literature review of perioperative antibiotic administration in surgery for medication-related osteonecrosis of the jaw.

PURPOSE: Few studies exist that focus on the details of perioperative antibiotic administration for surgery to treat medication-related osteonecrosis of the jaw (MRONJ). The regime and duration of perioperative antibiotics applied in published studies were reviewed to clarify appropriate perioperative antibiotic use in MRONJ surgery. METHODS: A literature search was conducted using the MEDLINE database via PubMed. RESULTS: The search resulted in 453 hits on PubMed. After reading the downloaded full-text articles, 17 articles met the inclusion and exclusion criteria. The most common perioperative antibiotic used for MRONJ surgery was a combination of penicillin-based antibiotics and ß-lactamase inhibitor (52.9%), and the second most common regime was penicillin-based antibiotics with metronidazole (17.6%). The duration of administration was 2 weeks postoperatively in nine studies, whereas four studies applied long-term administration (2-6 weeks postoperatively). CONCLUSIONS: Oral and maxillofacial surgeons mostly prefer penicillin-based antibiotics plus ß-lactamase inhibitor or metronidazole for MRONJ surgery. The duration of administration of these medications may be based on empirical experience.

Gold nanoparticles enhance X-ray irradiation-induced apoptosis in head and neck squamous cell carcinoma in vitro.

Enhancing the antitumor effect of radiation, while reducing damage to organs, is a significant challenge in radiation therapy for head and neck malignancies. One promising radiosensitizer is gold. The present study aimed to determine whether gold nanoparticles (AuNPs) have the potential to enhance the effects of X-ray irradiation on head and neck cancer cells. The human head and neck carcinoma cell line HSC-3 was used. Total cell number and the levels of cell proliferation and apoptosis were compared between control cells and cells treated with 5-nm AuNPs alone at four concentrations (0.1, 0.4, 1.0 and 10.0 nM), X-ray irradiation alone at three doses (2, 4 and 8 Gy), or a combination of 4 Gy X-ray irradiation and 1.0 nM AuNPs. Analysis of variance and Tukey-Kramer testing were performed to compare the different groups. The total number of cells significantly decreased following 4 and 8 Gy X-ray irradiation, compared with in the control group (control vs. 4Gy, P=2.19×10-4; control vs. 8Gy, P=1.28×10-6). The combination of 4 Gy X-ray irradiation and 1.0 nM AuNPs significantly reduced the total number of cells compared with 4 Gy X-ray irradiation alone (P=2.95×10-4). Cell proliferation was not affected by AuNP treatment alone, 4 Gy X-ray irradiation alone or the combination of X-ray irradiation and AuNPs. The combination of 4 Gy irradiation and 1.0 nM AuNPs significantly increased the number of apoptotic cells compared with 4 Gy irradiation alone (P=0.0261). In conclusion, AuNPs combined with X-ray irradiation enhanced the cytotoxic effect on human head and neck cancer cells in vitro, through the induction of apoptosis, but not inhibition of cell proliferation.