Prevention, detection, and diagnosis of head and neck cancers

Nutlin-3, A p53-Mdm2 Antagonist for Nasopharyngeal Carcinoma Treatment

Nasopharyngeal carcinoma (NPC) is a form of head and neck cancer of multifactorial etiolo-gies that is highly prevalent among men in the population of Southern China and Southeast Asia. NPC has claimed many thousands of lives worldwide; but the low awareness of NPC remains a hindrance in early diagnosis and prevention of the disease. NPC is highly responsive to radiotherapy and chemothera-py, but radiocurable NPC is still dependent on concurrent treatment of megavoltage radiotherapy with chemotherapy. Despite a significant reduction in loco-regional and distant metastases, radiotherapy alone has failed to provide a significant improvement in the overall survival rate of NPC, compared to chemo-therapy. In addition, chemo-resistance persists as the major challenge in the management of metastatic NPC although the survival rate of advanced metastatic NPC has significantly improved with the admin-istration of chemotherapy adjunctive to radiotherapy. In this regard, targeted molecular therapy could be explored for the discovery of alternative NPC therapies. Nutlin-3, a small molecule inhibitor that specifi-cally targets p53-Mdm2 interaction offers new therapeutic opportunities by enhancing cancer cell growth arrest and apoptosis through the restoration of the p53-mediated tumor suppression pathway while pro-ducing minimal cytotoxicity and side effects. This review discusses the potential use of Nutlin-3 as a p53-activating drug and the future directions of its clinical research for NPC treatment.

Audit of nutritional guidelines for head and neck cancer patients undergoing radiotherapy

BACKGROUND

Head and neck cancer patients being treated with radiotherapy are at an increased risk of malnutrition due to the severe side-effects, e.g. mucositis, odynophagia and xerostomia, impacting on the ability to eat and drink. Effective dietetic management involves identifying those patients malnourished or at risk of becoming so and incorporating nutritional intervention into their treatment plan. The use of gastrostomy tubes in this patient group has been shown to be acceptable. By placing them prophylactically, the aim is to prevent a disruption to treatment and avoid an unnecessary admission for feeding. This audit was carried out to determine whether the implementation of locally produced nutritional guidelines improved the dietetic management of this patient group.

METHOD

A prospective audit tool was used to collect data on 32 head and neck cancer patients undergoing radiotherapy. Data was collected weekly during the course of treatment and compared with data from previous audits. Weight change was the nutritional outcome measured.

RESULTS

More patients underwent combined treatment (radiotherapy postoperatively or with concurrent weekly chemotherapy) when compared with previous audits. However, implementation of the guidelines appeared to contribute to an improvement in dietetic management, as fewer patients lost weight over the course of radiotherapy and there were no admissions for feeding. The presence of a dietitian at the multidisciplinary head and neck clinic improved access and communication and this is also likely to have contributed to the improved management.

CONCLUSIONS

Implementation of the guidelines led to an improvement in the nutritional management of this patient group. Implementation may be more likely if a dietitian is present at the combined head and neck clinic.

Human papillomaviruses in lymph node neck metastases of head and neck cancers

CONCLUSION

The results of this study corroborate earlier findings that human papillomavirus (HPV)16 is the most prevalent type of HPV in squamous cell carcinomas of the head and neck (SCCHNs) and reinforce a possible influence of HPV on SCCHN progression by showing that the majority of HPV-positive patients harbor HPV16 (or HPV33) both in their primary tumors and in lymph node neck metastases (LNNMs).

OBJECTIVE

HPVs are causally associated with carcinomas of the uterine cervix and have also been linked to a subset of SCCHNs. In order to further investigate the predicted causative role of HPV in SCCHNs, we analyzed pairs of primary tumors and LNNMs or LNNMs alone for the presence of HPV DNA using polymerase chain reaction (PCR).

MATERIAL AND METHODS

DNA was extracted from fresh frozen tissue samples of primary tumors and the corresponding LNNMs of 18 patients and from LNNMs alone in 17 patients. For the detection and typing of HPV, PCR was performed using both type-specific and consensus primer pairs, followed by Southern hybridization and, in selected cases, sequencing of the PCR products.

RESULTS

Of the 35 patients investigated, 22 (63%) were found to have HPV DNA in their tumors: HPV16 DNA in 21 cases and HPV33 in 1. The highest HPV prevalence was detected in tumors of Waldeyer's tonsillar ring (8/9 patients; 89%). Of the 18 patients in whom primary tumors and LNNMs were analyzed, 7 (39%) were HPV-positive in both samples (HPV16, n = 6; HPV33, n = 1), in 3 (17%) the primary tumors were HPV-negative and the LNNMs HPV16-positive and in 1 (5.5%) the primary tumor contained HPV16 and the LNNM was negative. Interestingly, of the 7 patients in whom LNNMs had been detected only several months after diagnosis and treatment of the primary tumors, only 1 showed infection with HPV (HPV33).

Prevalence of human papillomavirus in squamous cell carcinoma of the head and neck determined by polymerase chain reaction and Southern blot hybridization: proposal for optimized diagnostic requirements

Human papillomaviruses (HPV) are discussed as cofactors in the carcinogenesis of squamous cell carcinoma of the head and neck (SCCHN). The prevalence of HPV infection in SCCHN is the subject of controversy since reported HPV prevalences range from less than 10% to almost 100%, depending mainly on the detection method employed. This study presents a realistic approximation to the real prevalence of HPV in SSCHN by applying polymerase chain reaction (PCR) and Southern blot hybridization (SBH), which are the most sensitive and specific HPV detection methods. Diagnostic procedures were optimized by applying a "hot-start" PCR protocol followed by a confirmatory SBH of the PCR products to reactions using both type-specific and consensus primers and probes. DNA of 75 tumour samples and 22 normal mucosa samples of the same patients were investigated. In 14 cases genomic SBH using complete HPV genomes as probes was performed additionally. HPV DNA was detected in 17/75 (22.7%) SCCHN specimens. HPV 16 was identified in four cases, HPV 45 in three cases, and HPV 6 and 18 in one case each. Hot-start PCR and SBH are the most reliable HPV detection methods, as they minimize both false-positive and false-negative results. With these methods, a HPV prevalence of 23% was achieved, which can be assumed to be representative for comparable study populations. The significant number of positives detected only by consensus primer PCR, along with the identification of HPV 45, indicate that further HPV types may play an important role in the genesis of SCCHN.

Analysis of human papillomavirus DNA in oral squamous cell carcinomas

Evidence from several laboratories suggests that HPV plays a role in the etiology of squamous cell carcinomas of the oral cavity. A multifactorial risk factor profile for the development of oral cancer may include HPV in addition to well-established risk factors such as tobacco and alcohol use. The prevalence of oral carcinomas reported to be associated with HPV has varied widely due to differences in the sensitivity of the assay used for HPV detection. The aims of this study were: (1) to ascertain the prevalence of HPV DNA in oral squamous cell carcinomas using the most sensitive technique available, the polymerase chain reaction; (2) to determine the type of HPV in the tumors; and 3) to correlate the virologic data with other risk factor data obtained from patients' records. Fourteen (78%) of 18 primary tumors, 6 (67%) of 9 normal epithelial tissues from the patients and 5 (100%) of 5 neck metastases were HPV DNA-positive. Of the 14 HPV DNA-positive primary tumors, specific typing revealed HPV 16 in 2, HPV 18 in 2, HPV 16 and 18 in 5, HPV 6/11, 16 and 18 in 4, and HPV 6/11 in 1. HPV types in the normal or metastatic tissue were usually the same as those in the respective primary tumor. There was no significant association between HPV presence and any of 12 factors or patient characteristics studied.