Oral Oncology

Editorial Board/Aims & Scope

2010-08-01

Robotic surgery in head and neck cancer: A review

2010-06-09

Summary: The invasion of robotic technology in surgical fields cannot be ignored. Its success in various surgical disciplines especially in urology, cardiology, and gynaecology has set its own benchmarks. Extrapolation of similar results in head and neck is still in experimental stages and long term results are still eagerly awaited to truly establish its efficacy beyond awe and reality. Nonetheless, its future role in this area is inevitable given the encouraging results obtained so far. This article covers the inception to current application to speculation of robotic technology in complex area of head and neck surgery.

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

2010-04-20

Summary: 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.

Chronic exposure to heavy metals and risk of oral cancer in Taiwanese males

Che-Chun Su, Kuo-Yang Tsai, Yun-Ying Hsu, Yo-Yu Lin, Ie-Bin Lian — 2010-07-09

Summary: The incidence of oral cancer has increased rapidly over the past 20years in Taiwan. Cigarette smoking and betel quid chewing are considered as the most important risk factors. However, we found that Changhua, a county in Taiwan, had the highest oral cancer incidence, but a modest prevalence of smoking and betel quid chewing. Our previous study found that the incidence of oral cancer in Taiwan has a strong spatial correlation with the heavy metal concentrations in farm soils of patients’ residential areas. A high content of heavy metals in farm soil is likely the result of industrial activities. If exposure to heavy metals is a risk factor for oral cancer, we would expect to find evidence from epidemiologic trends. The age–period–cohort model was used to analyze chart records from the Taiwan Cancer Registry of 21,135 male patients diagnosed with oral cancer from 1983 to 2002. Although the incidence increased in both Changhua and Taiwan overall, Changhua had a similar incidence to that in Taiwan as a whole until 1990, when the incidence in Changhua began to speed up, leaving a marked difference with that in Taiwan. Exposure to the heavy metal pollution for a period of more than 10years has an impact on the incidence of oral cancer. This novel factor can explain the extremely high incidence in Changhua.

Head and neck cancer in a developing country: A population-based perspective across 8years

2010-07-09

Summary: Head and neck cancer (HNC) has been studied in different regions of the world but little is known about its incidence patterns in the Middle East and Egypt.In this study from Egypt’s only population-based registry, we analyzed data from 1999 to 2006, to estimate incidence, incidence rate ratios (IRRs) and 95% confidence intervals (CIs) categorized by age, district and subsites.Overall urban incidence of HNC was twice or more that of rural incidence for both males (IRR=2.59; 95% CI=2.26, 2.97) and females (IRR=2.00; 95% CI=1.64, 2.43). Highest urban–rural difference for males was seen in 40–49years (IRR=2.79; 95% CI=1.92, 4.05) and for females in 30–39years (IRR=2.94; 95% CI=1.60, 5.40). Among subsites, highest incidence among males was for larynx (1.53/105) and among females for gum and mouth (0.48/105). Maximum urban–rural difference in males was for paranasal sinus (IRR=4.66; 95% CI=1.88, 11.54) and in females for lip (IRR=8.91; 95% CI=1.89, 41.98).The study underscores the patterns of HNC incidence in Egypt while indicating the need for future analytical studies investigating specific risk factors of HNC in this population.

Feasiblity of transoral robotic hypopharyngectomy for early-stage hypopharyngeal carcinoma

2010-07-09

Summary: Conventional surgical approaches for hypopharyngeal carcinomas have a great risk for developing treatment-related morbidity. To minimize this morbidity, hypopharyngectomy by transoral robotic surgery (TORS) was performed, and the efficacy and feasibility of this procedure were evaluated. TORS was performed using da Vinci Surgical Robot (Intuitive Surgical Inc., Sunnyvale, CA) in 10 patients with T1 or T2 pyriform sinus cancer and posterior pharyngeal wall cancer. FK retractor (Gyrus Medical Inc., Maple Grove, MN) was used for transoral exposure of the lesion. A face-up 30-degree endoscope was inserted through the oral cavity and two instrument arms were located in both sides of the endoscope. Pyriform sinus was totally resected as a cone-shape from the vallecular to apex region, and ipsilateral arytenoid cartilage was saved for function preservation. The aryepiglottic fold was resected medially. Laterally, the inner perichondrium of the thyroid cartilage was peeled off after perichondrium was incised horizontally to make sure of the safe margin of antero-lateral portion. The posterior margin is an inferior constrictor muscle of the posterior pharyngeal wall. We evaluated the robotic set up time, robotic operation time, blood loss, surgical margins, swallowing time, decannulation time, and surgery related complications. Transoral robotic hypopharyngectomy was performed successfully in all 10 patients. The mean robotic operation time was 62.4min, and an average of 17.5min was required for the setting of the robotic system. There was no significant perioperative complication in the cases. Swallowing function returned to all patients within 8.3days average. Decannulation was carried out within an average of 6.3days after surgery. Transoral robotic hypopharyngectomy was feasible and ontologically safe technique for the treatment of early hypopharyngeal cancer.

Diagnostic accuracy of diffusion-weighted MR imaging for nasopharyngeal carcinoma, head and neck lymphoma and squamous cell carcinoma at the primary site

Devin Fong, Kunwar S.S. Bhatia, David Yeung, Ann D. King — 2010-07-09

Summary: The feasibility of performing diffusion-weighted MRI (DWI) of primary undifferentiated nasopharyngeal carcinoma (NPC) has not been assessed and it is unknown whether the apparent diffusion coefficients (ADC) of primary NPC differs from that of lymphoma or squamous cell carcinoma (SCC) in the head and neck.One hundred patients with newly diagnosed NPC, head and neck lymphoma or SCC underwent echo-planar DWI. ADCs of primary tumours were compared by Kruskal–Wallis test and Mann–Whitney U tests with Bonferroni correction using p<0.05 and p<0.017 respectively to indicate statistical significance. The utility of ADC thresholds for discriminating tumour histology was evaluated by receiver operating characteristic analysis. DWI was successful in 45/65 with NPC, 5/7 with lymphoma and 26/28 with SCC. Mean ADC (±SD) of NPC, lymphoma and SCC were 0.98±0.161, 0.75±0.190, 1.14±0.196 (×10−3mm2/s) respectively which were significantly different (p<0.001–0.003). Optimized ADC thresholds of 0.779, 0.768 and 1.07(×10−3mm2/s) achieved maximal discriminatory accuracies of 100%, 93% and 70% for SCC/lymphoma, NPC/lymphoma, and SCC/NPC respectively. Echo-planar DWI is a feasible technique for investigating primary NPC although limited in a third of patients due to susceptibility artifacts around the skull base. While the overall ADC value of NPC is significantly different to that of SCC and lymphoma, on a case by case basis overlapping ADCs between these tumours limit its theoretical utility at this site. Nevertheless, DWI may still be useful clinically to distinguish NPC from nasopharyngeal lymphoma in populations with endemic NPC due to the relative rarity of nasopharyngeal SCC.

Role of adjuvant chemotherapy in malignant mucosal melanoma of the head and neck

2010-07-09

Summary: The objective of this study was to analyze the role of adjuvant chemotherapy and prognostic factors in malignant mucosal melanoma of the head and neck (HNMM). Thirty-two patients with mucosal melanoma of the head and neck who received local treatment with or without adjuvant chemotherapy were reviewed. Clinicopathologic parameters including anatomic sites, gender, age (⩽60 vs.>60years), stage, level of invasion, p53 and MDM2 [murine double minute 2] expressions, performance status, and adjuvant chemotherapy were evaluated. The patients’ median age was 62years, and 16 (50%) received adjuvant chemotherapy. Expressions of p53 and MDM2 were demonstrated in six of 24 and three of 26 cases, respectively. Predictors of poor survival according to univariate analysis were level of invasion and anatomic location of the primary tumor. Patients who received adjuvant chemotherapy had prolonged survival (p=0.002), which was also shown in the multivariate Cox regression model (HR, 0.24; p=0.014). Our analysis suggests a significant role of adjuvant chemotherapy and different patterns of p53 and MDM2 expression in HNMM relative to cutaneous melanomas. However, since this study is retrospective and observational, with a small sample size, further studies are needed to confirm the definitive role of adjuvant chemotherapy in the treatment of malignant mucosal melanoma of the head and neck.

The lip-splitting mandibulotomy: Aesthetic and functional outcomes

2010-07-09

Summary: To determine the aesthetic and functional outcomes of the most invasive approach to oral cavity/oropharyngeal lesions, the lip-splitting mandibulotomy approach (LSMA), versus the least invasive, the trans-oral approach (TOA). Retrospective paired-cohort study. Thirty-six patients with oral/oropharyngeal cancers treated with primary surgical extirpation, bilateral neck dissections and adjuvant radiation therapy were enrolled. Half underwent LSMA and half TOA. Patients were paired into gender, age and follow-up time matched cohorts. The primary outcome measure was overall patient satisfaction with scar cosmesis assessed with a 10-point Likert scale. Clinician and naïve viewer ratings of disfigurement in addition to the validated Vancouver scar scale (VSS) and patient and observer scar assessment scale (POSAS) were completed. Functional outcomes included lower-lip sensation and movement as well as oral continence assessment. LSMA patients had very high satisfaction and low perceptions of disfigurement with no statistically significant differences between cohorts (p>.05). VSS and POSAS results failed to demonstrate significant differences between groups (p>.05). Naïve observers, however, found the LSMA to be more disfiguring than TOA scars (p=.03). No significant differences in lower-lip sensation to touch, two-point discrimination or temperature distinction were found (p>.05). House–Brackman and movement symmetry scores were significantly indifferent between cohorts (p>.05). Video-fluoroscopic swallowing studies showed no difference in oral continence between cohorts (p>.05). The LSMA provides satisfactory scarring and low self-perception of disfigurement for patients. Moreover, the LSMA does not impact lower-lip sensation, movement or oral continence.

Nasopharyngeal mucoepidermoid carcinoma: A review of 13 cases

2010-07-16

Summary: Nasopharyngeal mucoepidermoid carcinoma (MEC) is an extremely rare entity. To date, there is little published about its clinical characteristics and treatment outcomes. Between 1997 and 2009, 13 cases of MEC were confirmed and treated at the department of Radiation Oncology, Cancer Hospital of Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC). Nasal obstruction, bleeding and hearing loss were the most common presentations, whereas, neck mass, headache and cranial nerve palsy were uncommon. Tumors remained stable after either primary radiation therapy or post-operative radiation therapy for the residual, though the majority of them were high or high-intermediate grade tumors. Five patients, who received either primary surgery or salvage surgery, had positive surgical margins, however, all are alive with stable disease except one old patient died of heart failure. The overall median survival of our patients was 43months, ranging from 8 to 80months. Based on the present results, we recommend that primary surgery should be the standard of care for all non-metastatic tumors regardless of histopathologic grade, and post-operative radiation therapy should be considered under the circumstances of positive surgical margins, macroscopic residual tumors, and high grade carcinomas.

Functional variants of COX-2 and risk of tobacco-related oral squamous cell carcinoma in high-risk Asian Indians

Manasi Mittal, Vaishali Kapoor, Bidhu Kalyan Mohanti, Satya Narayan Das — 2010-07-12

Summary: We assessed the association of COX-2 polymorphisms at promoter sites −1195, −765 and at 3′UTR (8473) in 193 patients with oral squamous cell carcinoma (OSCC) and 137 normal subjects by PCR–RFLP. Although no significant difference was observed in the frequency of COX-2 −1195G>A, −765G>C and 8473C>T single nucleotide polymorphisms (SNPs) between patients and controls, COX-2 −1195G/A genotype showed higher while −765G/C and 8473C/T showed lower prevalence in patients as compared to normal subjects. Logistic regression analysis of these three polymorphisms revealed a quantitative risk associated with −1195G>A SNP (OR 3.07 at 95%CI) while −765G>C and 8473C>T appeared to be protective. Results of the present study indicate that these three functional variants in the COX-2 regulatory region may contribute to risk modification of tobacco-related oral squamous cell carcinoma in Asian Indians.

Letter to the editor: “Is preoperative ultrasonography accurate in measuring tumor thickness and predicting the incidence of cervical metastasis in oral cancer?”

W.L. Lodder, M. Hauptmann, H.J. Teertstra, M.W.M. van den Brekel, A.J.M. Balm — 2010-04-05

We would like to take the opportunity to comment on the recently published article by Taylor et al. “Is preoperative ultrasonography accurate in measuring tumor thickness and predicting the incidence of cervical metastasis in oral cancer?”. As the authors mention, tumor thickness in oral cancer is an important predictive marker for lymph node metastases and can be useful for the management of primary tumor and neck. Since 1986, several studies have focused on the prognostic importance of tumor thickness of primary oral cancer. Natori et al. correlated tumor thickness as measured by both histopathology and ultrasound to the risk of lymph node metastasis. In multivariate analyses, tumor thickness on ultrasound was a significant predictor of neck metastases. (Cut-off point 8mm, expected risk of 67.4% on metastatic disease, p=0.04.) Given the available evidence in the literature, we disagree with Taylor et al. asserting they are “the first to correlate tumor thickness measured by ultrasonography with the risk of cervical lymph node metastases.”

Response to the comments on “Is preoperative ultrasonography accurate in measuring tumor thickness and predicting the incidence of cervical metastasis in oral cancer?”

S. Mark Taylor — 2010-06-10

I appreciate the comments made by Dr. Lodder and colleagues with regards to our paper “Is preoperative ultrasonography accurate in measuring tumor thickness and predicting the incidence of cervical metastasis in oral cancer.” There appears to be no debate that preoperative ultrasound is helpful in measuring tumor depth and therefore can be used for planning the subsequent treatment of the clinically negative neck. I thank him for stressing to the readership of Oral Oncology that there remains considerable debate as to the appropriate cutoff depth for performing an elective neck dissection in early oral cancer. I do agree with Dr. Lodder that given our sample size of 21 patients it is difficult to draw any conclusions with regards to this specific cutoff point. In our cohort of patients, however, none had cervical metastasis if their tumor thickness was less than 5mm and this was found to be statistically significant with a p-value of 0.0351. His group does refer to a recently published metanalysis published by Huang et al. out of the University of Toronto where the optimal cutoff point was determined to be 4mm. The review included 1136 patients and there was a statistically significant difference between the 4mm and 5mm tumor thickness cutoff points. Our conclusion that an elective neck dissection should be strongly considered if the tumor thickness is 5mm or above remains true in our study group, however, there is mounting evidence that a significant number of patients (16.6% according to the review by Huang et al.) with 4mm thick tumors would also benefit from an elective neck dissection. I think most of us would agree that ongoing research in this area is required before any conclusive statements be made with regards to this.