Molecular classification of head and neck squamous cell carcinomas using patterns of gene expression.

The prognostication of head and neck squamous cell carcinoma (HNSCC) is largely based upon the tumor size and location and the presence of lymph node metastases. Here we show that gene expression patterns from 60 HNSCC samples assayed on cDNA microarrays allowed categorization of these tumors into four distinct subtypes. These subtypes showed statistically significant differences in recurrence-free survival and included a subtype with a possible EGFR-pathway signature, a mesenchymal-enriched subtype, a normal epithelium-like subtype, and a subtype with high levels of antioxidant enzymes. Supervised analyses to predict lymph node metastasis status were approximately 80% accurate when tumor subsite and pathological node status were considered simultaneously. This work represents an important step toward the identification of clinically significant biomarkers for HNSCC.

Esophagogastroduodenoscopy in a public referral hospital in Lilongwe, Malawi: spectrum of disease and associated risk factors.

BACKGROUND: Esophagogastroduodenoscopy (EGD) is a valuable tool for diagnosing and treating upper gastrointestinal disease. Prioritizing the use of EGD in resource-limited settings must be customized to local populations to maximize population benefit from the examination. METHODS: Cross-sectional, retrospective review of EGD reports was conducted at Kamuzu Central Hospital (KCH), Lilongwe, Malawi. Esophageal tumors were defined as obstructive or nonobstructive and esophageal varices were graded on a scale of I to IV. Descriptive statistics were calculated and logistic regression performed for each disease state compared with all other reports. RESULTS: A total of 1,034 cases were reviewed (56% male; mean age (standard deviation), 44 (17) years). The most common indications were dysphagia (37%), hematemesis (21%), and epigastric pain (16%). The most common diagnoses were normal (36%), esophageal cancer (27%), and esophageal varices (17%). Eighty-six percent of esophageal tumors were obstructive and 45% of esophageal varices were grade III or IV. Normal examinations were more likely to be female, younger, and present with dyspepsia. Esophageal cancers were more likely to be male, older, present with dysphagia, and present from districts outside Lilongwe. Esophageal varices were more likely to present with hematemesis. CONCLUSIONS: EGD is a limited resource at KCH; patient selection should be guided by patient age and indication. The high burden of esophageal cancer and varices in Malawi suggests that therapeutic endoscopy would be beneficial.

Surgery and global public health: the UNC-Malawi surgical initiative as a model for sustainable collaboration.

Addressing global health disparities in the developing world gained prominence during the first decade of the twenty-first century. The HIV/AIDS epidemic triggered much interest in and funding for health improvement and mortality reduction in low- and middle-income nations, particularly in sub-Saharan Africa. Alliances between U.S. academic medical centers and African nations were created through the departments of internal medicine and infectious disease. However, the importance of addressing surgical disease as part of global public health is becoming recognized as part of international health development efforts. We propose a novel model to reduce the global burden of surgical diseases in resource poor settings by incorporating a sustained institutional surgical presence with our residency training experience by placing a senior surgical resident to provide continuity of care and facilitate training of local personnel. We present the experiences of the University of North Carolina (UNC) Department of Surgery as part of the UNC Project in Malawi as an example of this innovative approach.

BIIB021, a novel Hsp90 inhibitor, sensitizes head and neck squamous cell carcinoma to radiotherapy.

Heat shock protein 90 (Hsp90) is a molecular chaperone that promotes the conformational maturation of numerous client proteins, many of which play critical roles in tumor cell growth and survival. The ansamycin-based Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in Phase III clinical testing. However, 17-AAG is difficult to formulate and associated with dose-limited toxicity issues. A fully synthetic and bioavailable Hsp90 inhibitor, BIIB021, was evaluated for antitumor activity in a variety of head and neck squamous cell carcinoma (HNSCC) cell lines and HNSCC xenograft models, either as a single agent or in combination with fractionated radiation and the results were compared with that of 17-AAG. BIIB021 showed strong antitumor activity, comparable with, and in certain instances, superior to 17-AAG. BIIB021 enhanced the in vitro radiosensitivity of HNSCCA cell lines with a corresponding reduction in the expression of key radioresponsive proteins, increased apoptotic cells and enhance G2 arrest. In xenograft studies, BIIB021 exhibited a strong antitumor effect outperforming 17-AAG, either as a single agent and or in combination with radiation, thereby improved the efficacy of radiation. These results suggest that this synthetic and bioavailable Hsp90 inhibitor affects multiple pathways involved in tumor development and progression in the HNSCC setting and may represent a better strategy for the treatment of HNSCC patients, either as a monotherapy or a radiosensitizer. Furthermore, it also demonstrates the benefits of using preclinical models of chemosensitization to radiotherapy to explore clinically relevant radiation dosing schemes.

The role of endoscopy after upper gastrointestinal bleeding in sub-Saharan Africa: A prospective observational cohort study.

Background: Upper gastrointestinal (UGI) bleed is a common surgical disease in sub-Saharan Africa where there is often a lack of diagnostic and interventional adjuncts such as endoscopy. This study sought to characterize the role of endoscopy in management of acute UGI bleeding. Materials and Methods: This is a prospective observational analysis of adults presenting with an UGI bleed to a tertiary center in Lilongwe, Malawi, over two years. Patients were classified as having no endoscopy, diagnostic endoscopy, or endoscopy with variceal banding. Bivariate, survival analysis, and logistic regression analyses were used to compare intervention cohorts. Results: 293 patients were included with 49 patients (16.7%) receiving endoscopy with banding, 65 (22.2%) patients receiving diagnostic endoscopy only, and 179 (61.1%) receiving no endoscopy. Upon survival analysis comparing to the no endoscopy group, cox hazard modelling showed an adjusted hazard ratio over 30 days of 0.12 (95% CI 0.02, 0.88, p=0.038) for the endoscopic banding group and a hazard ratio of 0.39 (95% CI 0.13, 1.16, p=0.090) for the diagnostic endoscopy only group. Physical exam findings consistent with cirrhosis and decreasing age were independent predictors of an endoscopic diagnosis of variceal bleeding. Conclusion: Esophagogastric varices are a common cause of UGI bleeding in sub-Saharan Africa and can be predicted with age and physical exam findings. Endoscopy with variceal banding has a survival benefit for patients presenting with acute UGI bleed even with relatively low utilization. Appropriately triaging patients with likely variceal bleeding and improving endoscopy capacity would likely have a significant impact on mortality.

Defining cancer cachexia in head and neck squamous cell carcinoma.

PURPOSE: Cancer cachexia is a devastating and understudied illness in patients with head and neck squamous cell carcinoma (HNSCC). The primary objective was to identify clinical characteristics and serum levels of cytokines and cachexia-related factors in patients with HNSCC. The secondary objective was to detect the occurrence of cytokine and cachexia-related factor gene expression in HNSCC tumors. EXPERIMENTAL DESIGN: For the primary objective, cross-sectional data were obtained from prospectively recruited patients identified as cachexia cases and matching cachexia-free controls. For the secondary objective, a retrospective cohort design with matched controls was used. RESULTS: Clinical characteristics associated with cancer cachexia in HNSCC were T(4) status (P = 0.01), increased C-reactive protein (P = 0.01), and decreased hemoglobin (P < 0.01). Exploratory multiplex analysis of serum cytokine levels found increased interleukin (IL)-6 (P = 0.04). A highly sensitive ELISA confirmed the multiplex result for increased IL-6 in cachectic patients (P = 0.02). Quality of life was substantially reduced in patients with cachexia compared with noncachectic patients (P < 0.01). All tumors of HNSCC patients both with and without cachexia expressed RNA for each cytokine tested and the cachexia factor lipid-mobilizing factor. There were no statistically significant differences between the cytokine and cachexia factor RNA expression of cachectic and noncachectic patients (each P > 0.05). No tumors expressed the cachexia factor proteolysis-inducing factor. CONCLUSION: We have identified clinical characteristics and pathophysiologic mechanisms associated with cancer cachexia in a carefully defined population of patients with HNSCC. The data suggest that the acute-phase response and elevated IL-6 are associated with this complex disease state. We therefore hypothesize that IL-6 may represent an important therapeutic target for HNSCC patients with cancer cachexia.

Correction: Molecular Subtypes in Head and Neck Cancer Exhibit Distinct Patterns of Chromosomal Gain and Loss of Canonical Cancer Genes.

[This corrects the article DOI: 10.1371/journal.pone.0056823.].

Comparison of animal models for head and neck cancer cachexia.

OBJECTIVES/HYPOTHESIS: Despite its negative impact on cancer patients, there are few animal models of cancer cachexia. Our hypothesis was that different human cell lines would variably induce cachexia. STUDY DESIGN: Prospective animal study. METHODS: We established two xenograft models in athymic mice and compared these with a cachexigenic cell line, the murine adenocarcinoma 16 (MAC16) cell line. Eight-week-old female, athymic mice were injected with human head and neck cell lines (JHU022, JHU012) and the MAC16 cell line. Body weight, food intake, body composition, leg weights, serum cytokines, and lipid mobilizing factor (LMF) were compared. RESULTS: Mean food intake for all groups was equivalent. Mean percent change in body weight after 18 days was 18%, 19%, 12%, and 3% for control, JHU012, JHU022, and MAC16 experimental groups, respectively. Both JHU022- and MAC16-injected mice showed wasting even when tumor burden was low. In contrast, mice injected with JHU012 developed larger tumors yet lacked evidence of cachexia. These mice demonstrated loss of lean body mass but not fat mass. Serum cytokine levels for interleukin (IL)-1 alpha and IL-1 beta were elevated in JHU022-bearing mice, whereas IL-1 alpha, IL-6, interferon (IFN)-gamma, and tumor necrosis factor alpha (TNF)-alpha were elevated in MAC16-bearing mice. LMF was present in both the JHU022 and JHU012 cell lines. CONCLUSIONS: The JHU022 cell line caused more severe cachexia than the JHU012 cells, suggesting these cell lines may be used to further study cancer cachexia. IL-1 alpha and IL-1 beta in the JHU022 model may be mediators of cachexia, whereas TNF-alpha, IFN-gamma, and IL-6 may be mediators in MAC16-induced cachexia.

The effect of altered Toll-like receptor 4 signaling on cancer cachexia.

OBJECTIVE: To determine whether mice unable to mount an intact inflammatory response because of a Toll-like receptor (TLR) pathway defect will develop less severe cancer cachexia. DESIGN: Prospective animal study. SETTING: Academic research center. SUBJECTS: Six- to eight-week-old, female C3H/HeJ mice (17-18 g) and age-, weight-, and sex-matched wild-type C3H/HeN mice, differing in that the HeJ mice have nonfunctional TLR4 due to a TLR4 double mutation (TLR4(d/d)). INTERVENTION: The mice were inoculated with equal numbers of SCCF-VII cells and housed in individual cages. MAIN OUTCOME MEASURES: Food intake, body weight, pretumor and posttumor body composition, circulating cytokines, and levels of a marker of muscle atrophy were analyzed. RESULTS: The wild-type HeN mice weighed less on average than the TLR4(d/d) mice (2.6 g vs 4.9 g) (P = .01). They consumed more food, had smaller tumors, and had less lean body mass and fat mass than the TLR4(d/d) mice. Interleukin 1beta level was significantly elevated in the tumor-bearing HeN mice (mean gain of 259 pg/mL) but not in the TLR4(d/d) mice (P = .03). Both mouse strains had evidence of muscle atrophy. CONCLUSIONS: In spite of increased food intake and smaller tumors, the wild-type HeN mice had more severe cachexia than the TLR4(d/d) mice. The impaired ability to secrete proinflammatory cytokines such as interleukin 1beta may protect these animals from developing severe cancer cachexia. This animal model represents a novel system in which the host contributions to cachexia may be further studied.

The effectiveness of salvage surgery after the failure of primary concomitant chemoradiation in head and neck cancer.

OBJECTIVE: To determine survival outcomes and locoregional control rates in patients with locoregional head and neck squamous cell cancer (HNSCC) who failed primary concomitant chemoradiation (CRT) intended for cure and underwent attempted surgical salvage. STUDY DESIGN AND SETTING: Design was a nonrandomized retrospective cohort study. Of 204 patients with HNSCC who received primary concomitant chemoradiation intended for cure between 1995 and 2004, 38 recurred and underwent attempted salvage surgery at a tertiary care academic center. RESULTS: Among the 38 patients undergoing surgical salvage, 12- and 24-month overall survival rates were 60 percent and 27 percent. Locoregional control at 24 months was 42 percent. Lower survival was seen with initial N3 disease (P = 0.0115). Overall surgical morbidity was 24 percent. CONCLUSION/SIGNIFICANCE: The results of salvage surgery after failed chemoradiation for HNSCC are poor. Those with N3 disease fare least well. Patients should be well informed about the realistic chances of cure and potential morbidity of surgery.

Risk factors for common cancers among patients at Kamuzu Central Hospital in Lilongwe, Malawi: A retrospective cohort study.

BACKGROUND: Little is known about risk factors for different cancers in Malawi. This study aimed to assess risk factors for and epidemiologic patterns of common cancers among patients treated at Kamuzu Central Hospital (KCH) in Lilongwe, and to determine the prevalence of Human Immunodeficiency Virus (HIV) infection in the same population. METHODS: We analysed data from the hospital-based KCH cancer registry, from June 2009 to September 2012, including data from a nested substudy on coinfections among cancer patients. Demographics and behavioural variables, including smoking and alcohol use, were collected through personal interviews with patients. We assessed HIV prevalence across cancer types. The distribution of cancer types was reported overall and by gender. Logistic regression was used to assess risk factors associated with common cancer types. RESULTS: Data from 504 registered cancer patients were included-300 (59.5%) were female and 204 (40.5%) were male. Mean age was 49 years (standard deviation, SD = 16). There were 343 HIV-negative patients (71.2%), and 139 (28.8%) were HIV-positive. The commonest cancers were oesophageal (n = 172; 34.5%), cervical (n = 109; 21.9%), and Kaposi's sarcoma (KS) (n = 52; 10.4%). Only 18% of cancer cases were histologically confirmed. Patients with oesophageal cancer were likely to be older than 50 years (odds ratio, OR = 2.22), male (OR = 1.47), and smokers (OR = 2.02). Kaposi's sarcoma patients had the highest odds (OR = 54.4) of being HIV-positive and were also more likely to be male (OR = 6.02) and smokers. Cervical cancer patients were more likely to be HIV-positive (OR = 2.2) and less than 50 years of age. CONCLUSIONS: Age, smoking, and HIV are important risk factors for the 3 commonest cancer types (oesophageal, KS, and cervical) at this teaching hospital in Malawi. HIV is the single most important risk factor for Kaposi's sarcoma and cervical cancer.

Human papillomavirus in head and neck squamous cell carcinoma: A descriptive study of histologically confirmed cases at Kamuzu Central Hospital in Lilongwe, Malawi.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is common in sub-Saharan Africa, but the aetiologic contribution of human papillomavirus (HPV) is not well established. METHODS: We assessed HNSCC cases for HPV using p16 immunohistochemistry (IHC) in Malawi. Associations between p16 IHC and tumour site, behavioural risk factors, demographic characteristics, and HIV status were examined. RESULTS: From 2010 to 2014, 77 HNSCC cases were identified. Mean age was 52 years, 50 cases (65%) were male, and 48 (62%) were in the oropharynx (OP) or oral cavity (OC). HIV status was known for 35 patients (45%), with 5 (14%) HIV-infected. Substance use was known for 40 patients (52%), with 38% reporting any tobacco and 31% any alcohol. Forty-two cases (55%) had adequate tissue for p16 IHC, of which seven (17%) were positive, including 22% of OP/OC tumours. CONCLUSIONS: Despite high cervical cancer burden, HPV-associated HNSCC is not very common in Malawi.

Potent activity of a novel dimeric heat shock protein 90 inhibitor against head and neck squamous cell carcinoma in vitro and in vivo.

Heat shock protein 90 (Hsp90) is a molecular chaperone that promotes the conformational maturation of numerous client proteins, many of which play critical roles in tumor cell growth and survival. The ansamycin-based Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in phase I/II clinical testing. However, 17-AAG is difficult to formulate and displays weak activity against some tumors. A novel dimeric ansamycin, EC5, was evaluated for antitumor activity in eight head and neck squamous cell carcinoma (HNSCC) cell lines. Both 17-AAG and EC5 inhibited tumor cell proliferation effectively, but EC5 was more potent, with IC(50) below 200 nmol/L in most cell lines tested, including several lines that were resistant to 17-AAG. The inability of 17-AAG to kill JHU12 cells was linked to a defect in retinoblastoma signaling and could be rescued by ectopic expression of p16(INK4a). EC5 induced G(1) growth arrest of tumor cells and apoptosis, with the degradation of client proteins including epidermal growth factor receptor, c-Raf-1, Akt, and Cdk4 and inhibition of Akt phosphorylation. In vivo, EC5 dramatically reduced the growth rate of established HNSCC xenografts in nude mice and decreased expression of epidermal growth factor receptor and Akt within the xenografts. These results suggest that this novel ansamycin-based Hsp90 inhibitor affects multiple pathways involved in tumor development and progression and may represent a new strategy for the treatment of HNSCC patients.

Hearing genes and cisplatin deafness: a pilot study.

OBJECTIVE: Cisplatin commonly is used to treat pediatric solid tumors. A major dose-limiting toxicity is sensorineural hearing loss. Which patients experience ototoxicity after treatment with cisplatin must reflect individual susceptibility, since it is not seen in all similarly treated patients. We hypothesized that mutations or polymorphisms in hearing genes are more common in patients who experience ototoxicity than in the general population. STUDY DESIGN: We completed retrospective mutation screening of GJB2 and SLC26A4 and screened for three mtDNA mutations in patients with a history of childhood cancer who developed severe hearing loss at cumulative cisplatin doses of less than 400 mg/M2. MATERIALS AND METHODS: Patients younger than 21 years of age who experienced severe hearing loss after cisplatin were identified using the Childhood Cancer Survivor Study database. Archival DNA from buccal washes of 11 patients was used for mutation screening and detection. RESULTS: With the exception of one patient (9.1%) who was a carrier for the 35delG mutation, no mutant alleles were found. Given the reported prevalence of the 35delG mutation in the general population of 2.5%, this result is not significant (P = .35). CONCLUSIONS: It is not likely that any of the five hearing genes we examined contribute to cisplatin ototoxicity. Further study may be warranted to look at other hearing genes as possible predictors of cisplatin ototoxicity.

Incidence and survival rates for young blacks with nasopharyngeal carcinoma in the United States.

OBJECTIVES: To compare the incidence rates of nasopharyngeal carcinoma (NPC) among US black, white, and Asian/Pacific Islander (Asian) populations, with a focus on those diagnosed before age 20 years and between ages 20 and 29 years. Our secondary objective was to determine differences in survival rates between US blacks, whites, and Asians with NPC who were younger than 30 years. DESIGN: Data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) tumor registry system were used to determine incidence and survival rates for cases of NPC diagnosed in the specified age groups between 1973 and 2002. PATIENTS: Blacks, whites, and Asians younger than 30 years with NPC. MAIN OUTCOME MEASURES: Incidence rates and 2- and 5-year survival rates. RESULTS: From 1973 to 2002, incidence rates per 1 million persons, adjusted to the 2000 standard population, for blacks, whites, and Asians younger than 20 years with NPC were 1.61 (n=43), 0.61 (n=99), and 0.95 (n=18), respectively. The incidence rate ratio of blacks to Asians younger than 20 years was 1.69 (95% confidence interval [CI], 0.96-3.12) (P=.07), while the rate ratio for blacks to whites was 2.66 (95% CI, 1.82-3.85) (P<.001). From ages 20 to 29 years, rates increased slightly in blacks (1.87) and whites (0.96), while increasing dramatically in Asians (7.18). Two- and 5-year relative survival rates in blacks younger than 30 years were 84% and 64%, respectively, with little variation between races in this age group. CONCLUSIONS: Blacks younger than 20 years have increased incidence rates of NPC relative to whites and may be the only group having a higher NPC incidence rate than Asians. Two- and 5-year survival rates of blacks, whites, and Asians younger than 30 years with NPC are similar.

Subtyping sub-Saharan esophageal squamous cell carcinoma by comprehensive molecular analysis.

Esophageal squamous cell carcinoma (ESCC) is endemic in regions of sub-Saharan Africa (SSA), where it is the third most common cancer. Here, we describe whole-exome tumor/normal sequencing and RNA transcriptomic analysis of 59 patients with ESCC in Malawi. We observed similar genetic aberrations as reported in Asian and North American cohorts, including mutations of TP53, CDKN2A, NFE2L2, CHEK2, NOTCH1, FAT1, and FBXW7. Analyses for nonhuman sequences did not reveal evidence for infection with HPV or other occult pathogens. Mutational signature analysis revealed common signatures associated with aging, cytidine deaminase activity (APOBEC), and a third signature of unknown origin, but signatures of inhaled tobacco use, aflatoxin and mismatch repair were notably absent. Based on RNA expression analysis, ESCC could be divided into 3 distinct subtypes, which were distinguished by their expression of cell cycle and neural transcripts. This study demonstrates discrete subtypes of ESCC in SSA, and suggests that the endemic nature of this disease reflects exposure to a carcinogen other than tobacco and oncogenic viruses.

Use, accuracy, and implications for patient management of [18F]-2-fluorodeoxyglucose-positron emission/computerized tomography for head and neck tumors.

OBJECTIVES/HYPOTHESIS: Positron emission tomography (PET) has shown promise for early detection and accurate staging of cancer patients. A limited number of studies suggest PET/computed tomography (CT) may improve these variables; however, no published study has specifically evaluated clinical outcomes with PET/CT for head and neck (HN) tumors. The current study evaluates the use, accuracy, and implications for patient management of PET/CT scans in patients with HN tumors. STUDY DESIGN: Retrospective cohort outcomes study at a tertiary care center. METHODS: The authors identified 795 consecutive PET/CT at our institution. A total of 113 were obtained for HN tumors; 97 were used in the final analysis. Accuracy, use, and implications for patient care management decisions were correlated with each PET/CT scan. Multiple regression analysis was performed. RESULTS: Accuracy, sensitivity, and specificity were measured by comparing the PET/CT results at the primary tumor site, cervical node sites, and distant sites with either pathologic or definitive clinical diagnoses. PET/CT had an overall per scan accuracy of 72% and a per patient accuracy of 69%. When stratification for rationale of obtaining the scan was performed, accuracy was 80% for staging distant disease, 67% for primary tumor evaluation, 72% for evaluation for recurrence, and 60% for unknown primary tumor evaluation. CONCLUSIONS: PET/CT imaging is a promising tool for evaluating HN tumors; however, in clinical practice, the proper use of such technology is not well studied. In our study, PET/CT had an overall accuracy of 72% in evaluating HN tumors, and PET/CT had the most accuracy in the detection of distant metastasis.

Cochlear implantation for children with GJB2-related deafness.

OBJECTIVES/HYPOTHESIS: Mutations in GJB2 are a common cause of congenital sensorineural hearing loss. Many children with these mutations receive cochlear implants for auditory habilitation. The purpose of the study was to compare the speech perception performance of cochlear implant patients with GJB2-related deafness to patients without GJB2-related deafness. STUDY DESIGN: Retrospective case review. METHODS: Pediatric cochlear implant recipients who have been tested for GJB2 mutation underwent chart review. All patients received cochlear implantation at a tertiary referral center, followed by outpatient auditory habilitation. Charts were reviewed for cause and duration of deafness, age at time of cochlear implantation, intraoperative and postoperative complications, duration of use, and current age. Results of standard tests of speech perception administered as a part of the patients' auditory habilitation were reviewed. RESULTS: Twenty patients with GJB2 mutations were compared with 27 patients without GJB2 mutations. There was no statistical difference between patients with and without GJB2-related congenital sensorineural hearing loss with regard to open-set and closed-set speech recognition performance at 12, 24, and 36 months after cochlear implantation. Surgical complications were uncommon. CONCLUSION: Pediatric patients with congenital sensorineural hearing loss without other comorbid conditions (eg, developmental delay, inner ear malformations) perform well when they receive cochlear implantation and auditory habilitation. The presence or absence of GJB2 mutation does not appear to impact speech recognition performance at 12, 24, and 36 months after implantation.

Clinical evaluation of a new molecular method for detection of micrometastases in head and neck squamous cell carcinoma.

OBJECTIVE: To better detect occult cervical metastases. DESIGN: RNA from 153 cervical lymph nodes was analyzed for the presence of squamous cell carcinoma using quantitative cytokeratin (CK) 14 real-time reverse transcription polymerase chain reaction (RT-PCR). Detection of CK RNA in pathologically negative nodes was further analyzed by semi-step sectioning and CK immunohistochemistry. Subjects Thirteen consecutive patients with head and neck squamons cell carcinoma (HNSCC) presenting to the Department of Otolaryngology/Head and Neck Surgery of the University of North Carolina at Chapel Hill for neck dissection. RESULTS: Cytokeratin detection was deemed nonspecific if expressed at fewer than 50 molecules of CK 14 RNA per nanogram total RNA. Of 35 HNSCCs, 33 expressed CK 14 RNA, and 15 lymph nodes with routine pathologically positive metastasis were also positive for CK 14 RNA. Four lymph nodes that were pathologically negative nodes were positive for CK 14 RT-PCR, with 2 containing metastases detected by semi-step sectioning. CONCLUSIONS: Cytokeratin 14 RT-PCR is very sensitive for detecting micrometastasis in lymph nodes that are negative by routine pathological examination, with a relatively high false-positive rate. Quantitative CK 14 RT-PCR could be used to identify nodes negative for tumor by standard pathological analysis that should be examined by step sectioning and CK immunohistochemistry. Identification of micrometastases in patients with HNSCC will allow for appropriate and aggressive treatment of patients with metastatic disease.

Molecular assay to detect metastatic head and neck squamous cell carcinoma.

BACKGROUND: The presence or absence of metastatic disease in cervical lymph nodes is the single most important determinant of therapy and prognosis for patients with head and neck squamous cell carcinoma (HNSCC). However, histologic examination fails to detect metastatic disease in a subset of neck dissection specimens. The accuracy of neck staging may be improved by the use of molecular techniques. Cytokeratins 5, 14, and 20 may be appropriate markers for HNSCC because they are expressed in HNSCC but not in lymphatic tissue. DESIGN: To test the sensitivity of detection of cytokeratin 5, 14, and 20 messenger RNA by quantitative reverse transcription polymerase chain reaction (RT-PCR), full-length coding DNA sequences were cloned and transcribed. The expression of cytokeratin 5, 14, and 20 messenger RNA was quantified in 4 HNSCC cell lines and 11 tumors. A cell culture lymph node model was created. RESULTS: As few as 32 molecules of cytokeratin 14 could be detected using quantitative RT-PCR. Cytokeratins 5 and 14 were easily detected in all 4 HNSCC cell lines and almost all tumors. Cytokeratin 20 was not a useful marker, as expression was absent or significantly reduced in cell lines and tumors. In the lymph node model, cytokeratin 14 quantitative RT-PCR was able to detect 1 cancer cell in a background of 10 million lymphatic cells. CONCLUSIONS: Quantitative RT-PCR detection of cytokeratin 5 or 14 is a sensitive new molecular technique that may be used for detection of cervical micrometastases in head and neck cancer.