Lymph-node metastasis following total laryngectomy and total pharyngolaryngectomy for laryngeal and hypopharyngeal squamous cell carcinoma: Frequency, distribution and risk factors

Impact of neck dissection in cN0 patients undergoing primary or salvage total laryngectomy

INTRODUCTION

It is debatable whether neck dissection is necessary in patients with advanced laryngeal carcinoma who are clinically node-negative (cN0). We assessed the effect of neck dissection on overall survival in patients with cN0 undergoing primary or salvage laryngectomy.

MATERIALS AND METHODS

A retrospective evaluation of cN0 patients who underwent primary or salvage total/pharyngolaryngectomy at a French tertiary facility in 2008-2018, with or without neck dissection, was carried out. Patients were divided into two groups: primary (n = 65) and salvage (n = 84).

RESULTS

Comparing subglottic (HR = 3.978; p = 0.023) and hypopharyngeal (HR = 2.958; p = 0.018) malignancies to other tumor subsites, the mortality rates were greater. The primary group had a greater rate of occult metastases (23.07% vs. 14.28%; p = 0.089) than the salvage. The average lymph node ratio was significantly different between the treatment groups (0.05 ± 0.04 vs. 0.17 ± 0.33; p = 0.004). If LNR > 0.05, we found poor survival rates (p < 0.001). Although performing a neck dissection during the primary treatment increased the 5-year OS rate (Yes 89.5% vs. No 83.3%; p = 0.062), there was no discernible difference in the salvage group (Yes 80.3% vs. No 78.6%; p = 0.806; Log-rank p > 0.05). For the predicted survival variables, no significant relationships were detected in the Cox regression analysis (all p-values > 0.05).

CONCLUSION

Although the primary group had a greater frequency of occult metastases, neither the primary group's survival outcomes nor those of the salvage laryngectomy cases were significantly affected by neck dissection. LNR and the location of the tumor were important variables that could affect survival and the choice to do a neck dissection.

[Nodal metastasis and value of neck dissection in T1/2 oropharyngeal and hypopharyngeal carcinomas]

BACKGROUND

Due to heterogeneous data, the indication for elective neck dissection (END) in patients with squamous cell carcinoma of the hypopharynx and oropharynx (HPSCC and OPSCC) in stages T1/2N0 is somewhat unclear. Therefore, in this multicenter study, we performed detailed analysis of the metastatic behavior of HPSCC and OPSCC.

MATERIAL AND METHODS

The nodal metastatic patterns of 262 HPSCC and OPSCC patients who had undergone surgery was retrospectively investigated. In addition, recurrence-free and overall survival were recorded. Furthermore, a systematic literature review on the topic was completed.

RESULTS

In patients with HPSCC, a discrepancy between clinical and pathologic N status was recorded in 62.1% of patients vs. 52.4% for p16- OPSCC, and 43.6% for p16+ OPSCC. The occult metastasis rate in cT1/2cN0 primary tumors was 38.9% for HPSCC vs. 17.8% (p16- OPSCC) and 11.1% (p16+ OPSCC). Contralateral metastases occurred in 22.2% of cases for HPSCC at stages cT1/2cN0, compared to only 9.1% for p16- OPSCC, and 0% for p16+ OPSCC patients.Patients with p16+ OPSCC had better recurrence-free and overall survival than p16- OPSCC and HPSCC patients. A direct association between patient survival and the extent of neck surgical therapy could not be demonstrated in our patients.

CONCLUSION

Patients with HPSCC are at risk for bilateral neck metastases from stage cT1/2cN0, justifying bilateral END. Patients with T1/2 OPSCC present with occult metastases ipsilaterally in >20% of cases; however, the risk for contralateral occult metastasis is <10%. Hence, in strictly lateralized cT1/2CN0 tumors, omission of contralateral END may be considered.

[Surgical Treatment of Hypopharyngeal Carcinoma, Neck Dissection and Adjuvant Postoperative Therapy of Oropharyngeal and Hypopharyngeal Cancer: Recommendations of the current S3 Guideline - Part II]

Part II of the S3 guideline report deals with the surgical treatment of hypopharyngeal carcinoma, neck dissection for oropharyngeal and hypopharyngeal carcinomas and adjuvant therapy options. Primary surgical therapy ± adjuvant radio- or radiochemotherapy and primary radio- or radiochemotherapy are established as primary therapies for local-regional hypopharyngeal carcinomas. Direct randomized comparisons of both basic therapeutic procedures were never conducted. Available registry data show a worse prognosis of hypopharyngeal carcinoma compared to oropharyngeal carcinomas in all locoregional tumor stages, regardless of the treatment method. For T1N0-T2N0 squamous cell carcinoma of the hypopharynx, there are no relevant differences in overall survival and locoregional relapse rate between primary surgical and primary non-surgical treatment. Primary surgical therapy ± adjuvant radiotherapy or radiochemotherapy and primary radiotherapy or radiochemotherapy are established as primary therapies for advanced but locoregionally limited hypopharyngeal carcinomas. Neck dissection is an integral part of the primary surgical treatment of oropharyngeal and hypopharyngeal cancer. There are only a few randomized studies on non-surgical organ preservation for advanced hypopharyngeal cancer as an alternative to pharyngolaryngectomy, but these have led to the recommendation of alternative concepts in the new guideline. The indication and implementation of postoperative adjuvant radiotherapy and radiochemotherapy for hypopharyngeal carcinoma do not differ from those for HPV/p16-negative and -positive oropharyngeal carcinoma.

Development and validation of a diagnostic model for predicting cervical lymph node metastasis in laryngeal and hypopharyngeal carcinoma

Objectives

The lymph node status is crucial for guiding the surgical approach for patients with laryngeal and hypopharyngeal carcinoma (LHC). Nonetheless, occult lymph node metastasis presents challenges to assessment and treatment planning. This study seeks to develop and validate a diagnostic model for evaluating cervical lymph node status in LHC patients.

Materials and methods

This study retrospectively analyzed a total of 285 LHC patients who were treated at the Department of Otolaryngology Head and Neck Surgery, Daping Hospital, Army Medical University, from January 2015 to December 2020. Univariate and multivariate logistic regression analyses were employed to construct the predictive model. Discrimination and calibration were used to assess the predictive performance of the model. Decision curve analysis (DCA) was performed to evaluate the clinical utility of the model, and validation was conducted using 10-fold cross-validation, Leave-One-Out Cross Validation, and bootstrap methods.

Results

This study identified significant predictors of lymph node metastasis in LHC. A diagnostic predictive model was developed and visualized using a nomogram. The model demonstrated excellent discrimination, with a C-index of 0.887 (95% CI: 0.835-0.933). DCA analysis indicated its practical applicability, and multiple validation methods confirmed its fitting and generalization ability.

Conclusion

This study successfully established and validated a diagnostic predictive model for cervical lymph node metastasis in LHC. The visualized nomogram provides a convenient tool for personalized prediction of cervical lymph node status in patients, particularly in the context of occult cervical lymph node metastasis, offering valuable guidance for clinical treatment decisions.

Development and validation of a nomogram to predict cervical lymph node metastasis in head and neck squamous cell carcinoma

Background

Head and neck cancers are a heterogeneous, aggressive, and genetically complex collection of malignancies of the oral cavity, nasopharynx, oropharynx, hypopharynx, larynx, paranasal sinuses and salivary glands, which are difficult to treat. Regional lymph nodes metastasis is a significant poor prognosis factor for head and neck squamous cell carcinoma. Metastasis to the regional lymph nodes reduces the 5-year survival rate by 50% compared with that of patients with early-stage disease. Accurate evaluation of cervical lymph node is a vital component in the overall treatment plan for patients with squamous cell carcinoma of the head and neck. However, current models are struggle to accurately to predict cervical lymph node metastasis. Here, we analyzed the clinical, imaging, and pathological data of 272 patients with HNSCC confirmed by postoperative pathology and sought to develop and validate a nomogram for prediction of lymph node metastasis in patients with head and neck squamous cell carcinoma.

Methods

We retrospectively analyzed the clinical, imaging, and pathological data of 272 patients with head and neck squamous cell carcinoma (HNSCC) confirmed by postoperative pathology at the Affiliated Hospital of Qingdao University from June 2017 to June 2021. Patients were randomly divided into the training and validation cohorts in a 3:1 ratio, and after screening risk factors by logistic regression, nomogram was developed for predicting lymph nodes metastasis, then the prediction model was verified by C-index, area under curve (AUC), and calibration curve.

Results

Of the 272 patients, seven variables were screened to establish the predictive model, including the differentiation degree of the tumor [95% confidence interval(CI):1.224~6.735, P=0.015], long-to-short axis ratio of the lymph nodes (95%CI: 0.019~0.217, P<0.001), uneven/circular enhancement (95%CI: 1.476~16.715, P=0.010), aggregation of lymph nodes (95%CI:1.373~10.849, P=0.010), inhomogeneous echo (95%CI: 1.337~23.389, P=0.018), unclear/absent medulla of lymph nodes (95%CI: 2.514~43.989, P=0.001), and rich blood flow (95%CI: 1.952~85.632, P=0.008). The C-index was 0.910, areas under the curve of training cohort and verification cohort were 0.953 and 0.938 respectively, indicating the discriminative ability of this nomogram. The calibration curve showed a favorable compliance between the prediction of the model and actual observations. The clinical decision curve showed this model is clinically useful and had better discriminative ability between 0.25 and 0.9 for the probability of cervical LNs metastasis.

Conclusions

We established a good prediction model for cervical lymph node metastasis in head and neck squamous cell carcinoma patients which can provide reference value and auxiliary diagnosis for clinicians in making neck management decisions of HNSCC patients.

Integrated computational screening and liquid biopsy approach to uncover the role of biomarkers for oral cancer lymph node metastasis

Cancer is an abnormal, heterogeneous growth of cells with the ability to invade surrounding tissue and even distant organs. Worldwide, GLOBOCAN had an estimated 18.1 million new cases and 9.6 million death rates of cancer in 2018. Among all cancers, Oral cancer (OC) is the sixth most common cancer worldwide, and the third most common in India, the most frequent type, oral squamous cell carcinoma (OSCC), tends to spread to lymph nodes in advanced stages. Throughout the past few decades, the molecular landscape of OSCC biology has remained unknown despite breakthroughs in our understanding of the genome-scale gene expression pattern of oral cancer particularly in lymph node metastasis. Moreover, due to tissue variability in single-cohort studies, investigations on OSCC gene-expression profiles are scarce or inconsistent. The work provides a comprehensive analysis of changed expression and lays a major focus on employing a liquid biopsy base method to find new therapeutic targets and early prediction biomarkers for lymph node metastasis. Therefore, the current study combined the profile information from GSE9844, GSE30784, GSE3524, and GSE2280 cohorts to screen for differentially expressed genes, and then using gene enrichment analysis and protein-protein interaction network design, identified the possible candidate genes and pathways in lymph node metastatic patients. Additionally, the mRNA expression of discovered genes was assessed using real-time PCR, and the Human Protein Atlas database was utilized to determine the protein levels of hub genes in tumor and normal tissues. Angiogenesis was been investigated using the Chorioallentoic membrane (CAM) angiogenesis test. In a cohort of OSCC patients, fibronectin (FN1), C-X-C Motif Chemokine Ligand 8 (CXCL8), and matrix metallopeptidase 9 (MMP9) were significantly upregulated, corroborating these findings. Our identified significant gene signature showed greater serum exosome effectiveness in early detection and clinically linked with intracellular communication in the establishment of the premetastatic niche. Also, the results of the CAM test reveal that primary OC derived exosomes may have a function in angiogenesis. As a result, our study finds three potential genes that may be used as a possible biomarker for lymph node metastasis early detection and sheds light on the underlying processes of exosomes that cause a premetastatic condition.

Application of an Interpretable Machine Learning Model to Predict Lymph Node Metastasis in Patients with Laryngeal Carcinoma

Objectives

A more accurate preoperative prediction of lymph node metastasis (LNM) plays a decisive role in the selection of treatment in patients with laryngeal carcinoma (LC). This study aimed to develop a machine learning (ML) prediction model for predicting LNM in patients with LC.

Methods

We collected and retrospectively analysed 4887 LC patients with detailed demographical characteristics including age at diagnosis, race, sex, primary site, histology, number of tumours, T-stage, grade, and tumour size in the National Institutes of Health (NIH) Surveillance, Epidemiology, and End Results (SEER) database from 2005 to 2015. A correlation analysis of all variables was evaluated by the Pearson correlation. Independent risk factors for LC patients with LNM were identified by univariate and multivariate logistic regression analyses. Afterward, patients were randomly divided into training and test sets in a ratio of 8 to 2. On this basis, we established logistic regression (LR), k-nearest neighbor (KNN), support vector machine (SVM), extreme gradient boosting (XGBoost), random forest (RF), and light gradient boosting machine (LightGBM) algorithm models based on ML. The area under the receiver operating characteristic curve (AUC) value, accuracy, precision, recall rate, F1-score, specificity, and Brier score was adopted to evaluate and compare the prediction performance of the models. Finally, the Shapley additive explanation (SHAP) method was used to interpret the association between each feature variable and target variables based on the best model.

Results

Of the 4887 total LC patients, 3409 were without LNM (69.76%), and 1478 had LNM (30.24%). The result of the Pearson correlation showed that variables were weakly correlated with each other. The independent risk factors for LC patients with LNM were age at diagnosis, race, primary site, number of tumours, tumour size, grade, and T-stage. Among six models, XGBoost displayed a better performance for predicting LNM, with five performance metrics outperforming other models in the training set (AUC: 0.791 (95% CI: 0.776–0.806), accuracy: 0.739, recall rate: 0.638, F1-score: 0.663, and Brier score: 0.165), and similar results were observed in the test set. Moreover, the SHAP value of XGBoost was calculated, and the result showed that the three features, T-stage, primary site, and grade, had the greatest impact on predicting the outcomes.

Conclusions

The XGBoost model performed better and can be applied to forecast the LNM of LC, offering a valuable and significant reference for clinicians in advanced decision-making.

Different Primary Sites of Hypopharyngeal Cancer Have Different Lymph Node Metastasis Patterns: A Retrospective Analysis From Multi-Center Data

Background

Most hypopharyngeal cancers (HPCs) develop lymph node metastasis (LNM) at initial diagnosis. Understanding the pattern of LNM in HPC could help both surgeons and radiologists make decisions in the management of cervical lymph nodes.

Methods

A total of 244 newly diagnosed HPC patients between January 2010 and December 2018 were recruited from three specialized cancer hospitals in mainland China. All patients received pre-treatment magnetic resonance imaging (MRI), and definitive radiotherapy with or without concurrent chemotherapy. We reassessed the features of the primary tumor (tumor size, primary location, and extent of invasion) and the involvement of lymph nodes at each level. According to the incidence of LNM, these levels were sequenced and sorted into drainage stations. Univariate and multivariate analyses were used to determine the risk factors for bilateral and regional lymph node metastasis.

Results

The cohort consisted of 195 piriform sinus cancers (PSC), 47 posterior wall cancers (PWC), and 2 post-cricoid cancers (PCC). A total of 176 patients (72.1%) presented with MRI-detectable LNMs. The overall LNM rates for level II-VI and retropharyngeal lymph nodes (RPLNs) were 59.0%, 52.9%, 14.3%, 1.6%, 2.9%, and 16.4%, respectively. Based on the prevalence of LNM at each level, we hypothesize that the lymphatic drainage of PSC was carried out in sequence along three stations: Level II and III (61.0% and 55.4%), Level IV and RPLN (15.9% and 11.3%), and Level V and VI (1.5% and 3.1%). For PWCs, lymphatic drainage is carried out at two stations: Level II, III, and RPLN (48.9%, 40.4%, and 34.0%) and Level IV-VI (6.4%, 0%, and 2.1%). According to univariate and multivariate analyses, posterior wall invasion was significantly correlated with bilateral LNM (P = 0.030, HR = 2.853 95%CI, 1.110-7.338) and RPLN metastasis (P = 0.017, HR = 2.880 95%CI, 1.209-6.862). However, pyriform sinus invasion was less likely to present with bilateral LNM (P = 0.027, HR = 0.311, 95%CI, 0.111-0.875) and RPLN metastasis (P = 0.028, HR = 0.346, 95%CI, 0.134-0.891).

Conclusions and Relevance

The primary tumor site and extent of invasion are related to the pattern of lymph node metastasis. That is, the metastasis would drainage station by station along different directions.

Distribution of Metastases in Ent Area – Comparison of Theory and Practice

In head and neck cancers the occurrence of nodal metastases is the most important prognostic factor. Their early diagnosis is crucial for proper treatment. Detection of early metastases is still very difficult. Predictive diagnostic methods such as the sentinel lymph node detection is limited by the occurrence of skip metastases. At our Clinic we prefer a selective neck dissection based on a surgical treatment of predilected lymphatic spread area for each type of head and neck tumor with a preservation of non-lymphatic structures of the neck. The main objective of this article is to analyze the distribution of neck metastases and to study the frequency of skip metastases in head and neck cancer.

Patterns of Cervical Lymph Node Metastasis in Locally Advanced Supraglottic Squamous Cell Carcinoma: Implications for Neck CTV Delineation

Objective

To investigate the prevalence and distribution of cervical lymph node metastasis (LNM) in locally advanced supraglottic squamous cell carcinoma (LASCC) and guide the delineation of clinical lymph node target volumes.

Materials and Methods

We reviewed patients defined as LASCC from January 2000 to December 2017 in our hospital. The primary tumor was operated on using partial or total laryngectomy, and all patients underwent bilateral neck dissection (levels II–IV at least). Univariate and multivariate logistic regressions were used to find risk factors associated with LNM.

Results

A total of 206 patients were enrolled. In the whole group, the rate of ipsilateral metastasis (IM) was 60.9% (67 patients), whereas contralateral metastasis was 25.5% (28 patients). Only positive ipsilateral lymph nodes contributed to contralateral metastasis (p = 0.001). Seventy-six cases were diagnosed with clinical positive lymph nodes (cN⁺). IM of primary lesions mainly located within the unilateral sites (n = 49 patients) was detected in levels II, III, and IV with lymph node metastasis ratios of 73.5% (36 patients), 63.3% (31 patients), and 20.4% (10 patients), respectively, and contralateral metastasis of 36.7% (18 patients), 16.3% (8 patients), and 6.1% (3 patients), respectively. Involvement of level II or III was associated with metastasis of level IV. No one developed contralateral level IV involvement without metastasis of contralateral levels II and III. A total of 130 cases had clinically negative neck lymph nodes (cN0). The prevalence of occult metastasis (OM) was 35.4%. Among 62 patients with unilateral lesions, the rates of OM to ipsilateral neck levels II, III, and IV were 21, 11.1, and 1.6%, respectively, whereas contralateral neck levels were 6.3, 4.8, and 0%, respectively. In terms of the risk factors, histopathological differentiation was related to OM (p = 0.003). Two of 25 people were with level VIb metastasis, and both of them were with subglottic involvement.

Conclusion

Neck levels II to IV are most frequently involved and should be included in clinical target volume (CTV) in cN⁺ patients. Contralateral IV may be omitted when contralateral levels II and III are negative. In cN0 patients, ipsilateral levels II and III are suggested to be included in the CTV, whereas whether contralateral levels II and III should be included needs further research.

Clinical significance of neuropilin-2 expression in laryngeal squamous cell carcinoma

PURPOSE

The purpose of the study is to evaluate the expression of NRP-2 and explore its role in Laryngeal squamous cell carcinoma (LSCC).

MATERIALS AND METHODS

NRP-2 expression in 70 primary LSCC tissue specimens were analyzed by immunohistochemistry and correlated with clinicopathological parameters and patients´ survival rate. Additionally, 9 paired LSCC tissues were evaluated for NRP-2 expression by Western blotting.

RESULTS

The Western blotting indicated that NRP-2 expression levels in LSCC were significantly higher than those in the paraneoplastic tissues (P < 0.05). Immunohistochemistry staining revealed that NRP-2 was detected in all primary tumor samples, moreover, high expression of NRP-2 was significantly correlated with TNM stage (P < 0.05), clinical stage (P < 0.05), histological classification (P < 0.05), lymph node metastasis (P < 0.05) and recurrence (P = 0.001). Survival curves determined by the Kaplan-Meier method showed that high expression of NRP-2 can reduce overall survival (both group P < 0.05). Then we combined the NRP-2 expression and lymph node status, and Kaplan-Meier survival showed patients with high expression of NRP-2 or lymph node metastasis (+) had both shorter disease-free and overall survival than others (both P < 0.05). Multivariate Cox proportional hazards model analysis confirmed that histological grade (P = 0.045), lymph node metastasis (P = 0.020) and high expression of NRP-2 (P = 0.033) were statistically significant, independent predictor of prognosis.

CONCLUSIONS

NRP-2 may contribute to LSCC progression and represents as a novel prognostic indicator as well as a potential therapeutic target for LSCC.

Patterns of regional lymph node failure of locally advanced hypopharyngeal squamous cell carcinoma after first-line treatment with surgery and/or intensity-modulated radiotherapy

Background

To identify the spatial patterns of regional lymph node failure of locally advanced hypopharyngeal squamous cell carcinoma (SCC) after first-line treatment with surgery and/or intensity-modulated radiotherapy (IMRT).

Methods

We retrospectively obtained the clinicopathological characters of 123 hypopharyngeal SCC patients, and investigated the patterns of regional lymph node failure. Univariate and multivariate logistic regression were used to determine the risk factors of regional lymph node failure.

Results

Forty patients (32.5% of total patients) were suffered regional lymph node failure. In these patients, the ipsilateral neck level II nodal failure account for 55.0% (22/40) followed by level III 30.0% (12/40), level VIb 15.0% (6/40), level VII 15.0% (6/40), and level IV 5.0% (2/40). In addition, 17.5% (7/40) patients suffered contralateral neck level II nodal failure and 7.5% (3/40) patients suffered level III nodal failure. The common failure levels were the II (7/46, 15.2%), III (4/46, 8.7%), VIb (4/46, 8.7%), and VII (5/46, 10.9%) for treatment by surgery. The lymph node recurrence and persistent disease at levels II (19/77, 24.7%) and III (10/77, 13.0%) remained the major cause of failure following curative intent of IMRT. The postoperative radiation significantly decreased the risk of regional lymph node failure (OR = 0.082, 95% CI: 0.007–1.000, P = 0.049); and the radiologic extranodal extension significantly increased the risk of regional lymph node failure (OR = 11.07, 95% CI: 2.870–42.69, P < 0.001).

Conclusions

Whatever the treatment modality, the lymph node failure at level II and III was the most popular pattern for hypopharyngeal SCC. Moreover, for patients who underwent surgery, the nodal failure at level VIb and VII was frequent. Thus, postoperative radiation of level VIb and VII may give rise to benefit to locally advanced hypopharyngeal SCC patients.

Analyses of High-Risk Factors for Cervical Lymph Node Metastasis in Laryngeal Squamous Cell Carcinoma and Establishment of Nomogram Prediction Model

Laryngeal squamous cell carcinoma (LSCC) is one of the most common laryngeal tumors, and its incidence is increasing yearly; however, whether lymph node dissection should be performed during surgery remains unclear. We retrospectively analyzed the clinical and pathological data of 246 cases of LSCC and developed a nomogram for the prediction of lymph node metastasis (LNM) of LSCC. The predictive performance and consistency of the model were evaluated using the consistency coefficient (C-index) and calibration curve, respectively. Among 246 cases of LSCC, 52 cases had metastasis with a positivity rate of 21.14%. Multivariate analyses showed that dysphagia, clinical T stage, and pathological differentiation were independent risk factors for LNM in LSCC. The accuracy of the contour map used to predict the risk for LNM was 0.809. Overall, this nomogram model can be used to evaluate LNM in patients with LSCC before surgery to decide whether to conduct neck dissection and improve patient prognosis.

Photothermal therapy with AuNRs and EGFRmAb-AuNRs inhibits subcutaneous transplantable hypopharyngeal tumors in nude mice

The present study aimed to investigate the effects of photothermal therapy with gold nanorods (AuNRs) or epidermal growth factor receptor monoclonal antibody‑conjugated AuNRs (EGFRmAb‑AuNRs) on hypopharyngeal carcinoma (HC) in nude mice. In addition, the associated signaling pathways were explored. Briefly, a subcutaneous transplantable hypopharyngeal tumor model was established in nude mice injected with FaDu human HC cells. A total of 70 nude mice were randomly divided into seven groups, each of which received a different treatment. Mice were treated with AuNRs, locally or through intravenous injection, whereas EGFRmAb or EGFRmAb‑AuNRs were only administered locally. Near infrared spectroscopy (NIR) was also applied for plasmonic photothermal therapy (PPTT). The growth curve and the inhibitory rate for tumor growth were used to evaluate the effects of each treatment. Flow cytometry and the terminal‑deoxynucleotidyl transferase dUTP nick end labeling assay were adopted to detect apoptosis of cells in the transplanted tumors. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to determine the mRNA and protein expression levels of target genes, respectively. Local treatment with AuNRs + NIR or EGFRmAb significantly inhibited tumor growth, and EGFRmAb conjugation further increased the inhibitory effects. Furthermore, there was a significant increase in apoptosis of tumor cells in the AuNRs + NIR, EGFRmAb and EGFRmAb‑AuNRs + NIR groups; treatment with EGFRmAb‑AuNRs + NIR induced the highest apoptotic effect. Mechanistic studies indicated that EGFRmAb‑AuNRs + NIR may inhibit tumors through the AKT serine/threonine kinase (Akt) and DNA damage signaling pathways. In the AKT pathway, the mRNA and protein expression levels of phosphatase and tensin homolog were increased, whereas the expression levels of Akt and glycogen synthase kinase 3β were decreased. In the DNA damage signaling pathway, the mRNA and protein expression levels of ATR serine/threonine kinase, checkpoint kinase 1 and p53 were enhanced, whereas phosphorylated‑p53 protein expression was reduced. The present findings indicated that AuNRs + NIR inhibited HC tumor growth, and conjugating EGFRmAb to AuNRs further enhanced the inhibitory effects. EGFRmAb conjugation may increase the antitumor effects of AuNRs‑induced PPTT by downregulating the phosphatidylinositol‑3‑kinase/Akt pathway and upregulating the DNA damage pathway. These findings may provide novel insights into tumor‑targeting PPTT in vivo.