Effectiveness of adjuvant radiotherapy in patients with oropharyngeal and floor of mouth squamous cell carcinoma and concomitant histological verification of singular ipsilateral cervical lymph node metastasis (pN1-state)--a prospective multicenter randomized controlled clinical trial using a comprehensive cohort design

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)—A Prospective Multicentric Cohort Study

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55–1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15–0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19–0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

FOXD1 Repression Potentiates Radiation Effectiveness by Downregulating G3BP2 Expression and Promoting the Activation of TXNIP-Related Pathways in Oral Cancer

Simple Summary

Radioresistance remains a critical issue in treating oral cancer patients. This study was thus aimed to identify a potential drug target for enhancing the therapeutic effectiveness of irradiation and uncover a possible mechanism for radioresistance in oral cancer. Here we show that FOXD1, a gene encoding forkhead box d1 (Foxd1), is significantly upregulated in primary tumors compared to normal tissues and serves as a poor prognostic marker in oral cancer patients receiving radiotherapy. FOXD1 repression by a gene knockdown experiment dramatically enhanced the cytotoxic efficacy of irradiation probably via activating the p53-related DNA repairing pathways and reinforcing the T cell-mediated immune responses in oral cancer cells. Our findings demonstrate that FOXD1 may play a pivotal role in conferring radioresistance, which might provide a new strategy to combat the irradiation-insensitive oral cancer cells via therapeutically targeting FOXD1 activity.

Abstract

Radiotherapy is commonly used to treat oral cancer patients in the current clinics; however, a subpopulation of patients shows poor radiosensitivity. Therefore, the aim of this study is to identify a biomarker or druggable target to enhance the effectiveness of radiotherapy on oral cancer patients. By performing an in silico analysis against public databases, we found that the upregulation of FOXD1, a gene encoding forkhead box d1 (Foxd1), is extensively detected in primary tumors compared to normal tissues and associated with a poor outcome in oral cancer patients receiving irradiation treatment. Moreover, our data showed that the level of FOXD1 transcript is causally relevant to the effective dosage of irradiation in a panel of oral cancer cell lines. The FOXD1 knockdown (FOXD1-KD) dramatically suppressed the colony-forming ability of oral cancer cells after irradiation treatment. Differentially expressed genes analysis showed that G3BP2, a negative regulator of p53, is predominantly repressed after FOXD1-KD and transcriptionally regulated by Foxd1, as judged by a luciferase-based promoter assay in oral cancer cells. Gene set enrichment analysis significantly predicted the inhibition of E2F-related signaling pathway but the activation of the interferons (IFNs) and p53-associated cellular functions, which were further validated by luciferase reporter assays in the FOXD1-KD oral cancer cells. Robustly, our data showed that FOXD1-KD fosters the expression of TXNIP, a downstream effector of IFN signaling and activator of p53, in oral cancer cells. These findings suggest that FOXD1 targeting might potentiate the anti-cancer effectiveness of radiotherapy and promote immune surveillance on oral cancer.

Postoperative risk stratification in oral squamous cell carcinoma

Postoperative prognostic stratification using the Union for International Cancer Control (UICC) TNM 8th edition staging rules (UICC 8) may identify additional groups of patients who could benefit from adjuvant radiotherapy. Currently, selection for such treatment is not based on all known prognostic factors, and their relative importance may vary depending on the overall risk category. The objective of this study therefore was to evaluate these possibilities. We retrospectively studied 644 patients who had surgery with curative intent for oral squamous cell carcinoma (OSCC) between March 2006 and February 2017. The outcomes of interest were disease-specific survival (DSS) and locoregional recurrence (LRR). Patients were re-staged according to the UICC 8 staging rules. Putative clinical and pathological prognostic variables were evaluated and hazard ratios estimated. Regression analysis was done to identify independent prognostic factors, and iterative analyses identified clinically-relevant risk categories with a minimum of residual prognostic variables. The significance of recognised pathological prognostic factors differed according to the overall risk category. An intermediate risk group comprising patients with pN1 disease as well those with pT3 disease solely on the basis of a depth of invasion (DOI) of more than 10 mm, was identified. A trial to evaluate the benefit or otherwise of adjuvant radiotherapy in this group is now required. Individual prognostic risk factors should be considered within the context of the overall risk category in patients with OSCC.

Long-term outcomes in oral cavity squamous cell carcinoma with adjuvant and salvage radiotherapy after surgery

OBJECTIVE

Early-stage oral cavity squamous cell carcinoma (OCSCC) represents a heterogeneous group of patients, and locoregional recurrence rates are as high as 25% with surgery alone. Radiotherapy (RT) is typically reserved as part of salvage multimodality therapy after salvage surgery because it is generally thought that there is no significant detriment to salvage therapy. Our aim was to examine outcomes for recurrent OCSCC treated with salvage surgery and radiation and compare them to outcomes for patients treated with adjuvant postoperative RT upfront.

METHODS

We identified 425 patients with OCSCC treated with postoperative RT at our institution. The 5-year rates of local failure, locoregional failure (LRF), survival, and distant metastasis (DM) were the main outcome measures. We performed a landmark analysis and examined the same outcomes in the adjuvant versus salvage cohorts using Cox proportional hazards and Fine-Gray competing risk method.

RESULTS

The adjuvant cohort had higher tumor (T) (P < 0.0001) and nodal (N) (P < 0.0001) stage than the salvage cohort's stage at initial presentation. On multivariate analysis, a strategy of salvage RT experienced poorer overall survival (OS) compared to upfront adjuvant RT (hazard ratio [HR] 1.84; 95% confidence interval [CI], 1.26-2.70; P = 0.002). Moreover, salvage surgery followed by RT patients experienced increasing risk of LRF (HR 1.56; 95% CI, 1.18-2.06; P = 0.002) and (DM) (HR 1.53; 95% CI, 1.08-2.17; P = 0.02) on multivariate analysis. Additional analysis was performed excluding salvage cohort with advanced disease at initial presentation (T3-T4 and N2). Salvage RT treatment selection for early-stage OCSCC continued to experience significantly poorer OS as compared to adjuvant RT (HR 1.48; 95% CI, 1.002-2.19; P = 0.049).

CONCLUSION

Early-stage OCSCC patients who are observed and experienced recurrence requiring salvage therapy (surgery and RT) have worse oncologic outcomes than locally advanced patients receiving upfront adjuvant RT. Prospective randomized studies are needed to identify high-risk subset of early-stage OCSCC comparing adjuvant RT versus observation, followed by salvage surgery and RT at recurrence.

LEVEL OF EVIDENCE

4. Laryngoscope, 2539-2545, 2018.

Oral cancer: Current role of radiotherapy and chemotherapy

The term oral cavity cancer (OSCC) constitutes cancers of the mucosal surfaces of the lips, floor of mouth, oral tongue, buccal mucosa, lower and upper gingiva, hard palate and retromolar trigone. Treatment approaches for OSCC include single management with surgery, radiotherapy [external beam radiotherapy (EBRT) and/or brachytherapy], as well as adjuvant systemic therapy (chemotherapy and/or target agents); various combinations of these modalities may also be used depending on the disease presentation and pathological findings. The selection of sole or combined modality is based on various considerations that include disease control probability, the anticipated functional and cosmetic outcomes, tumor resectability, patient general condition, and availability of resources and expertise. For resectable OSCC, the mainstay of treatment is surgery, though same practitioners may advocate for the use of radiotherapy alone in selected "early" disease presentations or combined with chemotherapy in more locally advanced stage disease. In general, the latter is more commonly reserved for cases where surgery may be problematic. Thus, primary radiotherapy ± chemotherapy is usually reserved for patients unable to tolerate or who are otherwise unsuited for surgery. On the other hand, brachytherapy may be considered as a sole modality for early small primary tumor. It also has a role as an adjuvant to surgery in the setting of inadequate pathologically assessed resection margins, as does postoperative external beam radiotherapy ± chemotherapy, which is usually reserved for those with unfavorable pathological features. Brachytherapy can also be especially useful in the re-irradiation setting for persistent or recurrent disease or for a second primary arising within a previous radiation field. Biological agents targeting the epithelial growth factor receptor (EGFR) have emerged as a potential modality in combination with radiotherapy or chemoradiotherapy and are currently under evaluation in clinical trials.

Postoperative therapy in head and neck cancer: state of the art, risk subset, prognosis and unsolved questions

Head and neck cancer may be easily controlled at early stages, but resectable locally advanced disease often relapses at T and N sites. Therefore, adequate adjuvant treatment is of crucial importance for improving local control and/or survival. Unfortunately, little data are available on the adjuvant setting. Adjuvant radiotherapy is regarded as a standard approach for patients with locally advanced radically resected head and neck cancer, while postoperative chemotherapy alone cannot be considered outside of clinical trials. However, chemoradiotherapy is widely considered superior to radiotherapy in patients at a high risk of relapse and may be considered the standard treatment in this population. In this respect, in the last few decades, there has been a growing interest due to the emerging data on both tumor biology and clinical trials. Several pathological and molecular factors, affecting behavior and head and neck cancer prognosis, could allow for a better selection of postoperative treatment. More recently, new prognostic and predictive factors were identified, including biomolecular aspects, human papillomavirus infection and lifestyle. The integration of these new factors deserves dedicated clinical studies, but the available knowledge already allows some deductive hypotheses. We performed a review of the literature to analyze the role of therapy in the postoperative setting and to discuss both the possibility of a different approach to each class of risk and the unsolved question for which randomized trials are warranted.

Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy

BACKGROUND

The management of advanced oral cavity and oropharyngeal cancers is problematic and has traditionally relied on surgery and radiotherapy, both of which are associated with substantial adverse effects. Radiotherapy has been in use since the 1950s and has traditionally been given as single daily doses. This method of dividing up the total dose, or fractionation, has been modified over the years and a variety of approaches have been developed with the aim of improving survival whilst maintaining acceptable toxicity.

OBJECTIVES

To determine which radiotherapy regimens for oral cavity and oropharyngeal cancers result in increased overall survival, disease free survival, progression free survival and locoregional control.

SEARCH STRATEGY

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 28 July 2010), CENTRAL (The Cochrane Library 2010, Issue 3), MEDLINE via OVID (1950 to 28 July 2010) and EMBASE via OVID (1980 to 28 July 2010). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Randomised controlled trials where more than 50% of participants had primary tumours of the oral cavity or oropharynx, and which compared two or more radiotherapy regimens, radiotherapy versus other treatment modality, or the addition of radiotherapy to other treatment modalities.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of risk of bias was undertaken independently by two or more authors. Study authors were contacted for additional information as required. Adverse events data were collected from published trials.

MAIN RESULTS

30 trials involving 6535 participants were included. Seventeen trials compared some form of altered fractionation (hyperfractionation/accelerated) radiotherapy with conventional radiotherapy; three trials compared different altered fractionation regimens; one trial compared timing of radiotherapy, five trials evaluated neutron therapy and four trials evaluated the addition of pre-operative radiotherapy. Pooling trials of any altered fractionation radiotherapy compared to a conventional schedule showed a statistically significant reduction in total mortality (hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.76 to 0.98). In addition, a statistically significant difference in favour of the altered fractionation was shown for the outcome of locoregional control (HR 0.79, 95% CI 0.70 to 0.89). No statistically significant difference was shown for disease free survival.No statistically significant difference was shown for any other comparison.

AUTHORS' CONCLUSIONS

Altered fractionation radiotherapy is associated with an improvement in overall survival and locoregional control in patients with oral cavity and oropharyngeal cancers. More accurate methods of reporting adverse events are needed in order to truly assess the clinical performance of different radiotherapy regimens.

Indications for radiotherapy after neck dissection

Up-front surgery and postoperative radiotherapy constitute a well-recognized treatment concept for locally or regionally advanced squamous cell carcinoma of the head and neck. This "treatment package" is further intensified with the concomitant application of chemotherapy during irradiation when high-risk features (ie, microscopically involved resection margins, extracapsular extension of the tumor from neck nodes, the presence of soft tissue deposits) are found on histopathologic examination of a resected specimen. With regard to neck disease, however, the demarcation line between low- and higher-risk clinical situations, which would differ with respect to the need for postoperative radiotherapy, is not clear. In an attempt to define the low-risk characteristics of disease in the neck that do not require adjuvant irradiation, we reviewed the available literature reports for any direct or indirect evidence on the value of postoperative radiotherapy in various clinical scenarios. The number of positive lymph nodes found in a dissected tissue specimen that should be used as a "cut-off" point for introduction of postoperative radiotherapy was evaluated in the context of both primary tumor characteristics and type of neck dissection.

Postoperative strategies after primary surgery for squamous cell carcinoma of the head and neck

This review discusses the role of adjuvant treatment after curative surgery for patients with head and neck squamous cell carcinoma (HNSCC). In general, patients with unfavourable prognostic factors have a high-risk of loco-regional recurrence and subsequent worse survival after surgery alone and are therefore considered proper candidates for adjuvant treatment by either postoperative radiotherapy alone or postoperative chemoradiation. Selection of the most optimal adjuvant treatment strategy should be based on the most important prognostic factors. In this review, the different treatment strategies will be discussed in general. More specifically, we will discuss the role of the interval between surgery and radiotherapy, the overall treatment time of radiation, the selection of target volumes for radiation and the value of adding concomitant chemotherapy to postoperative radiation.