Phase II trial of interferon-alpha in locally recurrent or metastatic squamous cell carcinoma of the head and neck: immunological and clinical correlates

The objective of this study was to study the antitumor, host toxicity, and immunomodulatory effects of recombinant interferon-alpha 2b (IFN) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Seventy-one patients with recurrent or metastatic SCCHN were entered into a phase II noncomparative randomized trial of IFN at two dosage schedules. Eligible patients with histologically proven SCCHN were randomized to receive low-dose IFN, 6 x 10(6) U/m2 daily x 3 every 4 weeks or high-dose IFN, 12 x 10(6) U/m2, 3 x/week. Pretreatment levels of natural killer (NK) activity, CD3, CD4, CD5, CD8, CD16, CD19, CD56, DR, and the CD4/CD8 ratio were evaluated for any relationship with survival. The toxicity encountered in patients receiving low-dose IFN was for the most part mild to moderate. With high-dose IFN, toxicity was greater with significantly more episodes of grade 3 and 4 toxicity encountered. Dosage reduction was required in the majority of patients receiving high-dose IFN. Of the four lethal complications, only one was thought to be possibly associated with therapy. Of the 32 evaluable patients receiving low-dose IFN, there were 1 complete response, 1 stable disease, 24 patients with progressive disease, and 6 unevaluable. Of the 29 evaluable patients taking high-dose IFN, there were 2 complete responses, 7 with stable disease, 16 with progressive disease, and 4 patients were unevaluable. Median survival in the two arms was similar (6.2 months). Because it was postulated that a more prolonged exposure to IFN might be needed for it to be effective, patients receiving > or = 6 weeks of therapy were evaluated. Median survival in that subset was 10 and 12 months for patients receiving low- and high-dose IFN, respectively. None of the immune parameters tested was a significant predictor of survival when evaluated in all cases entered into study regardless of therapy duration. No difference in baseline NK activity was noted between patients who received < 6 or > or = 6 weeks of IFN (p = 0.90). However, among the 35 patients who received > or = 6 weeks of therapy, a high baseline NK activity was a significant predictor of the duration of survival (p = 0.04). IFN was well tolerated in patients with recurrent or metastatic SCCHN. The higher incidence of toxicity encountered in the high-dose arm could be ameliorated by reducing the dose 50%. In patients receiving 6 or more weeks of therapy, elevated baseline NK activity was associated with increases in survival, suggesting that IFN may play an immunomodulatory role. Although the overall response rates were low, disease stabilization was noted, suggesting an antiproliferative, noncytotoxic role of IFN in this group of heavily pretreated patients.

Text Learning Using Scientific Diagrams: Implications for Classroom Use

In two experiments, eighth-graders viewed ecologically valid diagrams and then read a text containing multiple feature-to-fact associations or studied the same materials in reverse order. Using the Kulhavy and Stock model of text learning using organized spatial displays, it was predicted that those students viewing the diagram prior to reading the text would recall more facts and features than subjects viewing the material in the reverse order. These predictions were well supported. In addition, since the materials used in the experiments were created from actual classroom materials, these experiments examined whether the model for text learning is also valid using this type of materials. In this area the model proved to be very effective as well.

The role of apoptosis in antibody-dependent cell-mediated cytotoxicity against monolayers of human squamous cell carcinoma of the head and neck targets

Antibody-dependent cellular cytotoxicity (ADCC) against squamous cell carcinoma of the head and neck (SCCHN) targets in the presence of human/mouse chimeric monoclonal antibodies (cMAbs), SF-25 and 323/A3, is mediated by natural killer (NK) cells. In 4-hr 51Cr-release assays with SSCHN targets in suspension, ADCC was always significantly better (P < 0.01) than that measured in parallel with the same target cells in monolayers. No differences were observed in the level of expression of the relevant antigens recognized by cMAbs on these targets. To better explain the difference, 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) monolayer and [3H]thymidine-release assays were used. Cytostasis and cell death measured in monolayer MTT assays and DNA fragmentation measured in [3H]thymidine-release assays were significantly higher (P = 0.028) than cytotoxicity determined using 51Cr-labeled SCCHN monolayers. Cell death observed in monolayer MTT assays was blocked by pretreating SCCHN targets with cycloheximide or actinomycin-D or by paraformaldehyde fixation of effector cells. The presence of apoptotic cells in monolayers co-incubated with effector cells was demonstrated in situ by labeling fragmented ends of DNA with fluorescein-conjugated dUTP and terminal deoxynucleotidyl transferase and also by flow cytometry of target cells obtained from such monolayers. Our results indicate that NK cells preferentially utilize membrane lysis (necrosis) in ADCC with tumor cell targets in single-cell suspensions. However, necrosis is not efficient in monolayers. In the presence of cMAbs, apoptosis is the primary mechanism of NK cell-mediated killing in monolayers of SCCHN targets, which were found to express receptors for tumor necrosis factor and fas ligand.

Protective effects of interferon-gamma on squamous-cell carcinoma of head and neck targets in antibody-dependent cellular cytotoxicity mediated by human natural killer cells

An in vitro model of antibody-dependent cellular cytotoxicity (ADCC) was established, using squamous-cell carcinoma of the head and neck (SCCHN) targets,human/mouse chimeric monoclonal antibodies (cMAbs) SF-25 and 323/A3 and human peripheral blood mononuclear cells (PBMC). We previously showed that natural killer (NK) cells are the main effector population mediating ADCC in the presence of the cMAbs. ADCC was significantly inhibited by the overnight pre-treatment of SCCHN targets with exogenous interferon-gamma (IFN-gamma). This inhibition was dose-dependent, reproducible and consistently observed with various SCCHN cell lines. SCCHN cells pre-treated with IFN-gamma had a significantly higher expression of intercellular adhesion molecule-I (ICAM-I) and major histocompatibility complex (MHC) class I antigens compared with untreated target cells. No differences in expression of the SCCHN-associated antigens on these targets or in the formation of NK-SCCHN conjugates were found, using flow cytometry. IFN-gamma-pre-treated SCCHN cells were less effective in competing with untreated targets in cold target inhibition assays and in inducing cytokine production from NK cells in co-incubation experiments. Protective effects of IFN-gamma on target cell sensitivity to lysis were blocked by pre-treatment of target cells with actinomycin-D or cycloheximide. The susceptibility of the target cells was restored by removal of MHC class I antigens from their surface by acid stripping before ADCC. Our results suggest that the decreased ADCC seen with SCCHN targets pre-treated with IFN-gamma is related to post-binding events, possibly altered signaling from targets to effector cells, and requires protein synthesis in the target cells.

Papillary thyroid carcinoma associated with squamous cell carcinoma of the head and neck: significance and treatment

Several studies in the recent literature would suggest that PTC found incidentally in the cervical lymphatics may be significant. By age alone, most of our head and neck cancer patients will fall into an intermediate risk group. There are also data to suggest that cervical metastasis from PTC may portend higher recurrence and mortality and that occult PTC may be a biologically significant situation. Many patients with cancer of the head and neck either have a good prognosis or don't follow the rules of their predicted prognosis, and for these patients living with the knowledge of an untreated thyroid, cancer may be an unnecessary concern. Other factors to be considered are that early PTC is probably curable disease and that there is real risk of transformation to higher grade or anaplastic cancer. Finally, there is no way to accurately predict the behavior of PTC. The decision to treat these cancers is ultimately made by the patient and the physician, and if there is a treatment with low morbidity that will alleviate concern of PTC recurrence, then this may outweigh the risk of treatment. Situations may exist when treating incidental PTC could be deferred. These include: a dismal prognosis for the head and neck primary when quality time outside of the hospital is the goal of the patient and the physician; or if the head and neck primary tumor requires external beam radiation therapy, because this may be adequate therapy for occult PTC. In summary, the scenario of PTC found incidentally in the neck treated for a head and neck SCC is unusual. Each patient will have a unique clinical situation based on the site and stage of the SCC, the age of the patient, and the treatment required for the SCC. Treatment options include total thyroidectomy, thyroid lobectomy, the administration of I131, and/or the use of external beam radiation, which must be weighed against the option of close clinical follow-up. In general, we recommend total thyroidectomy for PTC found incidentally in the cervical LNs for the reasons that have emerged from a recent review of the medical literature. We report 7 patients with synchronous head nad neck SCC and PTC who have all received surgical treatment for PTC (Table 1). In addition, we advocate postoperative radioiodine scanning with radioablation of metastatic or persistent PTC, or remnant ablation if uptake is greater than 2%. Our goal as head and neck surgeons should be to avoid inadequate therapy for incidental PTC.

Loss of heterozygosity of the short arm of chromosomes 3 and 9 in oral cancer

Loss of heterozygosity (LOH) on chromosomes 3p and 9p has been documented in a variety of malignancies, which suggests the presence of tumor suppressor gene loci on these chromosomes. We have studied 77 oral carcinomas for LOH using 16 microsatellite markers distributed over 5 human chromosomes. Fifty-five (71%) of these tumors showed LOH at one or more loci. A significant proportion of LOH at the informative tumors was observed at chromosomes 3p and 9p: 58% and 48%, respectively. A majority of the tumors showed losses at multiple loci on chromosomes 3p or 9p or on both. Our results suggest that tumor suppressor genes located on the short arms of chromosomes 3 and 9 may be involved in the pathogenesis of oral carcinoma. These regions of deletion observed in oral cancers overlap those reported in other neoplasms. However, we did not find any evidence of these changes in tumor margins with early pathological changes.

Subchronic effects of dieldrin and phenobarbital on hepatic DNA synthesis in mice and rats

Dieldrin, an organochlorine pesticide, has been shown to be hepatocarcinogenic in mice but not rats. Phenobarbital, in contrast, induces hepatic tumors in both mice and rats. Previous studies have shown that acute dietary exposure of rats or mice to either dieldrin or phenobarbital produces several liver changes, including centrilobular hypertrophy, induction of hepatic cytochrome P450, and increased liver weight. The present study examined the subchronic effect of dieldrin (0.1, 1.0, 3.0, 10.0 mg dieldrin/kg diet) and phenobarbital (10, 50, 100, 500 mg phenobarbital/kg diet) on the induction of hepatic DNA synthesis and hepatocyte lethality in male B6C3F1 mice and male F344 rats. Eight-week-old animals were treated as above and evaluated for hepatic DNA synthesis after 7, 14, 21, 28, and 90 days of continual treatment to dieldrin or phenobarbital. Maximal induction of hepatic DNA synthesis in mice was seen at the 14-, 21-, and 28-day sampling times. In rats, no significant increase in hepatic DNA synthesis or hepatocyte lethality was observed at any dose of dieldrin investigated. Phenobarbital produced a significant increase in hepatic DNA synthesis in both rat and mouse liver following 7 days of treatment. The induction of DNA synthesis in rat liver was transient, with the labeling index returning to control levels by 14 days of treatment. In contrast, mice treated with phenobarbital showed a significant increase in hepatic DNA synthesis throughout the treatment. In both mice and rats, dieldrin and phenobarbital induced hepatic DNA synthesis selectively in the centrilobular region of the hepatic lobule. The lack of an increase in serum enzymes indicative of hepatic damage and the absence of liver histopathology in mice or rats fed dieldrin or phenobarbital indicate that the induction of DNA synthesis was not mediated by a cytolethal, compensatory hyperplastic response, suggesting a mitogenic mechanism. Therefore, the species-specific induction of hepatic DNA synthesis by either dieldrin or phenobarbital correlated with the previously observed species-specific induction of hepatic cancer by these two compounds.

Congruence between education and reading levels of older persons

The educational levels of 57 middle-aged and elderly persons were compared with their reading levels as assessed by the Wide Range Achievement Test-Reading. Participants were recruited from mental health and community settings in a predominantly black community. Thirty-six participants (63 percent) were reading at a median of five years below their educational level. Forms used in the settings were written at a level above the reading ability of most participants. Results suggest that older persons may have difficulty comprehending written instructions for medications and diets and that such materials should be written at lower than an eighth-grade level.

Growth stimulation of human head and neck squamous cell carcinoma cell lines by interleukin 4

Interleukin 4 (IL-4) has been reported recently to inhibit growth of acute lymphoblastic lymphoma, non-Hodgkin's lymphoma, melanoma, sarcoma, breast, gastric, colon, and renal tumor cell lines, and treatment of murine tumors with IL-4 gene-transduced cells has been therapeutically successful. Therefore, we sought to determine the effect of IL-4 on the growth of human squamous cell carcinoma of the head and neck (SCCHN) cell lines. Growth of SCCHN cell lines incubated in the presence of various concentrations of IL-4 was measured in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assays and by cell counts. Specific binding of IL-4 to SCCHN cells was demonstrated by flow cytometry with phycoerythrin-labeled IL-4, blocking studies with antibodies to IL-4, and using the radiolabeled ligand 125I-labeled IL-4. Reverse transcription PCR for IL-4 and IL-4 receptor (IL-4R) mRNA was performed. SCCHN tissue biopsies were examined by immunohistology and in situ hybridization for the presence of IL-4 protein and IL-4 mRNA in the tumor, respectively. In contrast to earlier reports, we observed growth stimulatory effects of IL-4 consistently in 6 of 13 SCCHN cell lines tested. Growth stimulation by IL-4 ranged from 20 to 200% of control (P < 0.05) and was IL-4 dose dependent. The growth-promoting effect of IL-4 was inhibited completely by incubation of tumor cells in the presence of antibodies specific for IL-4. Reverse transcription PCR analysis of mRNA obtained from the SCCHN cell lines and ELISA performed with SCCHN cell supernatants respectively indicated that the tumor cells did not transcribe or secrete IL-4 actively. The SCCHN cell lines expressed 260-540 IL-4Rs/cell with a dissociation constant of 100 +/- 8 pM. SCCHN cell lines also contained IL-4R mRNA. Immunostaining of SCCHN tissue biopsies indicated that IL-4 may be produced and secreted within these tumors by tumor-infiltrating lymphocytes. In situ hybridization for IL-4 mRNA indicated the presence of positive cells in the tumor stroma. Our data suggest that IL-4 may regulate the growth of SCCHN cells by a paracrine mechanism. These data also indicate that immunotherapy with exogenous IL-4 or IL-4 gene therapy to treat head and neck cancer may not be effective, given the potential tumor growth-stimulatory effects of this cytokine.

A long-term assessment of adjuvant chemotherapy on outcome of patients with extracapsular spread of cervical metastases from squamous carcinoma of the head and neck

BACKGROUND

Extracapsular spread (ECS) of cervical lymph node metastases of squamous cell carcinoma from head and neck sites portend poor prognosis. Therefore, a program of combined surgery, postoperative irradiation therapy, and adjuvant methotrexate and 5-fluorouracil (5-FU) was initiated in 1982 for such patients.

METHOD

All patients operated on between June 1982 and December 1992 by the full-time faculty of the Department of Otolaryngology at the University of Pittsburgh School of Medicine were eligible and reported in this trial. All patients had negative surgical margins of excision of the primary carcinoma, and histologic evidence of cervical metastases with ECS. Postoperative irradiation included 50-60 cGy for 5 to 6 weeks followed by methotrexate and 5-FU administered on an outpatient basis on days 1 and 8 every 21 days. All patients were followed for 30 or more months for evidence of recurrent disease.

RESULT

A total of 371 patients met eligibility criteria. Of this group, 53 (14%) were treated with surgery only, 187 (50%) received surgery and postoperative irradiation, and 131 (35%) received surgery, irradiation therapy, and chemotherapy. The primary site, extent of nodal involvement, and stage of the three patient groups were similar. However, performance status (Karnofsky) was best in the patients who received chemoradiation (average 90) when compared with those who received surgery and irradiation (average 80) or surgery only (average 70). Absolute disease free survival rate (30 months) was 9.5% in patients treated with surgery only, 34% in patients treated with surgery plus irradiation, and 53% in patients treated with surgery, irradiation, and chemotherapy. When adjusted for patients who died of intercurrent disease with less than 30 months follow-up, survival rates became 17%, 40%, and 58%, respectively. These differences are highly significant (P < 0.001).

CONCLUSION

Results of this study suggest that postoperative chemoradiation may improve survival in patients with ECS of cervical metastases. Compliance with the chemoradiation was suboptimal and suggests that improved strategy must be developed.

Extracapsular spread in the clinically negative neck (N0): implications and outcome

Cervical metastasis is the most important prognostic factor in head and neck cancer patients. The prognostic significance of extracapsular spread of tumor in metastatic lymph nodes has also been documented. The presence of extracapsular spread further reduces the survival by 50% in those patients with cervical metastatic disease. Most patients with clinically negative necks (stage N0) have a good prognosis. However, some of these patients will have neck disease and distant metastasis and will eventually die. Because the presence of extracapsular spread is a predictor of poor outcome, we hypothesized that extracapsular spread may be a factor in the subset of patients with clinically negative necks who have poor outcomes. One hundred nine patients with clinically negative necks who had undergone neck dissection were identified. Occult metastasis was observed in 34% of patients. In this group, extracapsular spread was present in 18 (49%) patients. Overall, 103 patients were evaluable, of whom 70 (68%) remain free of disease 2 or more years after treatment. A subgroup of 68 patients had histologically negative nodes, of whom 56 (82%) are free of disease. Of patients with extracapsular spread, only 5 (31%) of 16 are free of disease. This is in contrast to patients with metastasis confined to the lymph node, of whom 9 (47%) of 19 are free of disease. Statistical analysis of these data shows that for this sample size this difference is significant. The addition of radiation therapy did not improve outcome in these patients. Extracapsular spread predicts a worse outcome in patients with subclinical cervical metastasis. Alternative modes of adjuvant therapy are suggested because of the poor results of postoperative radiation therapy in patients with extracapsular spread.

Extracapsular Spread in the Clinically Negative Neck (N0): Implications and Outcome

Cervical metastasis is the most important prognostic factor in head and neck cancer patients. The prognostic significance of extracapsular spread of tumor in metastatic lymph nodes has also been documented. The presence of extracapsular spread further reduces the survival by 50% in those patients with cervical metastatic disease. Most patients with clinically negative necks (stage N0) have a good prognosis. However, some of these patients will have neck disease and distant metastasis and will eventually die. Because the presence of extracapsular spread is a predictor of poor outcome, we hypothesized that extracapsular spread may be a factor in the subset of patients with clinically negative necks who have poor outcomes. One hundred nine patients with clinically negative necks who had undergone neck dissection were identified. Occult metastasis was observed in 34% of patients. In this group, extracapsular spread was present in 18 (49%) patients. Overall, 103 patients were evaluable, of whom 70 (68%) remain free of disease 2 or more years after treatment. A subgroup of 68 patients had histologically negative nodes, of whom 56 (82%) are free of disease. Of patients with extracapsular spread, only 5 (31%) of 16 are free of disease. This is in contrast to patients with metastasis confined to the lymph node, of whom 9 (47%) of 19 are free of disease. Statistical analysis of these data shows that for this sample size this difference is significant. The addition of radiation therapy did not improve outcome in these patients. Extracapsular spread predicts a worse outcome in patients with subclinical cervical metastasis. Alternative modes of adjuvant therapy are suggested because of the poor results of postoperative radiation therapy in patients with extracapsular spread.

Single screw fixation for acute and acute-on-chronic slipped capital femoral epiphysis

Charts and radiographs of 78 patients with slipped capital femoral epiphysis were reviewed. During the retrospective study period, 1990 to 1993, 16 patients had acute or acute-on-chronic slips; 21 hips were involved. Nine hips were acute and 12 hips were acute-on-chronic slips. No patient reported endocrinopathy or other systemic illness. All hips were fixed with a single 7-mm cannulated screw. No attempts were made for reduction. The lateral head-shaft angle (preoperative, postoperative, and at followup) was measured as was the position of the screw (postoperative and followup). Physeal closure in 19 hips occurred at a mean of 9.6 months. Two additional patients did not return for followup until 30 and 36 months after surgery. At closure, there was no significant change in head-shaft angle from preoperative position. No cases of avascular necrosis or chondrolysis were seen in this series. Seventeen of the 21 hips had an excellent functional result. Three hips had a good result and 1 had a poor result. There was a tendency for poor pin position and less satisfactory results to be associated. It is concluded that single screw fixation is adequate for treating uncomplicated acute and acute-on-chronic slipped capital femoral epiphyses.

Microsurgical reconstruction of the head and neck: interdisciplinary collaboration between head and neck surgeons and plastic surgeons in 305 cases

Three hundred five microsurgical free flaps have been performed for defects of the head and neck by a team of two head and neck surgeons and two plastic surgeons over a 9-year period, with a success rate of 91.2%. The most common flaps used were the jejunum (89), radial forearm (57), rectus abdominis (48), latissimus dorsi (40), scapular (32), fibula (15), and iliac crest (11). Thirty-three flaps required reexploration for anastomotic thrombosis or hematoma (10.8%), of which 18 flaps were salvaged (54.5%). Thirteen flap failures occurred in 113 patients who had received preoperative irradiation (11.5%), but this was not statistically significant. Seven flaps failed in 20 patients who required an interposition vein graft (35%) and this was statistically significant. Ninety patients (31.5%) developed a major complication other than anastomotic thrombosis or death. Despite postoperative intensive care nursing and monitoring, 18 patients died postoperatively in the hospital (6.3%). The average hospital stay was 21.1 days with a range from 5 to 95 days. During this 9-year time period, various free flaps have evolved as the preferred choice for free flap reconstruction of a specific defect of the head and neck. The latissimus dorsal muscle flap surfaced with a nonmeshed split-thickness skin graft is the optimal free flap for reconstruction of the scalp and skull, whereas a multiple-paddle latissimus dorsi musculocutaneous flap is the best flap for reconstruction of complex defects of the middle third of the face and maxilla. The radial forearm flap and free jejunal transfer have become the preferred choices for intraoral reconstruction and pharyngo-esophageal reconstruction, respectively. There still remains no universally accepted flap for mandibular reconstruction, but the fibular osteocutaneous flap and a reconstruction plate protected by a radial forearm flap have largely superseded the iliac crest and scapular osteocutaneous flaps. Radical resection of tumors of the head and neck with immediate reconstruction by microsurgical free tissue transfer followed by adjuvant radiation therapy provides the best possible chance for cure and functional and social rehabilitation of the patient.

Accuracy of intraoperative staging of the NO neck in squamous cell carcinoma

Management of the neck in squamous cell carcinoma of the upper aerodigestive tract continues to be a topic of great debate. One major problem is that incorrect clinical staging is expected in approximately 20% of necks. This is true of both clinical stage NO and N+ necks, even when imaging studies are used. This prospective study of 108 necks in 79 patients examined the role of intraoperative palpation and inspection in improving the surgeon's ability to predict nodal stage. Of 62 patients with NO necks clinically on both sides, 26 were staged N+ by intraoperative node examination. Nineteen of the 26 were histologically negative (73% false-positive). Of the 36 patients staged intraoperatively as NO, 10 were histologically positive (28% false-negative). Of 108 necks judged clinically to be NO, 25 (23%) had occult metastases and 11 (10%) had extracapsular spread. Forty-one of 108 clinical NO necks were believed to have positive nodes at the time of neck dissection. Of these 41 necks, 30 (73%) were found to be histologically NO (false-positive). Of the 67 clinical NO necks that were also believed to be NO intraoperatively, occult metastases were found in 14 (21% false-negative). Therefore, intraoperative staging did not significantly improve the false-negative rate. Frozen-section biopsy obtained in the operating room was reliable in 24 (92.3%) of 26 patients. Although frozen-section biopsy was not performed in all patients, these data suggest that upstaging the neck without frozen-section biopsy is much less reliable. This study supports the use of frozen-section biopsy before converting the selective dissection to a radical or modified neck dissection in most instances.

Previous tonsillectomy as prognostic indicator for success of uvulopalatopharyngoplasty

Factors that determine a successful outcome following uvulopalatopharyngoplasty (UPPP) for obstructive sleep apnea (OSA) are not well defined. This study was undertaken to determine if prior tonsillectomy is predictive of a lower response rate to UPPP. A retrospective review of a cohort undergoing UPPP alone or in combination with nasal septoplasty for OSA was undertaken. Preoperative and postoperative polysomnograms were obtained to evaluate the severity of the OSA. The sample was a consecutive series of 79 patients with OSA. Clinical evaluation was performed by both an otolaryngologist and a pulmonologist. Surgical treatment in this group of 79 patients included 52 UPPP and 27 UPPP in patients with prior tonsillectomy. Concurrent septoplasty was undertaken in 17 patients. Criteria for outcome were based on comparison of preoperative and postoperative polysomnograms (i.e., apnea index, respiratory disturbance index change, and lowest saturation). A response to therapy was defined as a reduction in apnea index greater than 50%. A success was defined as apnea index less than 5, reduction of respiratory disturbance index greater than 50%, and nadir saturation greater than 82%. In 79 patients with OSA, 78% responded and 37% reflected therapeutic successes. Patients with history of prior tonsillectomy were less likely to have therapeutic improvement following UPPP. In 52 patients without previous tonsillectomy, 88% responded and 52% had a successful outcome. Of those with previous tonsillectomy, 59% responded and 7% had a successful outcome. The status of previous tonsillectomy is an important prognostic indicator in the success of UPPP for the treatment of OSA. We speculate that the presence of palatine tonsils allows the removal of an extra measure of oropharyngeal tissue, thereby improving the likelihood of success for UPPP.

Microsatellite instability in oral cancer

Generalized genomic instability, detected as somatic changes in allele sizes at microsatellite loci in tumors compared to peripheral lymphocyte DNA, is a recently recognized mechanism of mutation in cancer. Such instability results from the somatic loss of DNA mismatch repair capability. Germ-line mutations at DNA mismatch repair loci confer susceptibility to colon cancer in hereditary non-polyposis colorectal cancer. Somatic loss of DNA mismatch repair has been reported in a large variety of other tumor types. Our goal was to determine the frequency of microsatellite instability in a large series of oral tumors. Out of 91 tumors analyzed for microsatellite instability, 6 (7%) showed microsatellite instability. Instability was observed at multiple loci with a range of 50-74% of loci affected. Alterations include both increase (74%) and decrease (26%) in allele sizes. The proportion of alleles affected ranged from 30-58% of all alleles. Our data suggest that somatic genomic instability plays a role in the pathogenesis of a small subset of oral tumors.

Adult respiratory papillomatosis: human papillomavirus type and viral coinfections as predictors of prognosis

Pathologic material and the records of 29 patients with laryngeal papillomatosis were reviewed. The relationship between the type of human papillomavirus (HPV) and the presence of viral coinfections was correlated with clinical outcome. Using polymerase chain reaction, paraffin-embedded specimens were analyzed for the presence of HPV, Epstein-Barr virus (EBV), cytomegalovirus (CMV), and herpes simplex virus (HSV). The HPV type could be identified in 24 patients' specimens. Twenty-one patients were infected with HPV type 6. The other 3 were infected with HPV type 11 or 16. Three patients developed squamous cell carcinoma, of whom 2 had HPV type 11 or 16. We found HSV, EBV, and CMV in 50%, 12.5%, and 0% of specimens, respectively. An aggressive clinical course was observed in 17 patients. Evidence of coinfection with other viruses was identified in 11 (65%) of these patients. In contrast, a benign clinical course was observed in 7 patients, of whom 2 (29%) had viral coinfections. We conclude that the HPV type and the presence of viral coinfections may be predictive of an aggressive clinical course.

The infected wound and its management

The infected wound is one of the most frequent causes of delayed wound healing. Even in the face of appropriate antibiotic prophylaxis, infections can occur in 10% to 20% of clean-contaminated procedures in the head and neck. The authors describe their comprehensive approach to prevent and manage the infected wound at the head and neck area.

Variation of p53 mutational spectra between carcinoma of the upper and lower respiratory tract

Mutations of the p53 tumor suppressor gene are the most common genetic alterations associated with human cancer. Tumor-associated p53 mutations often show characteristic tissue-specific profiles which may infer environmentally induced mutational mechanisms. The p53 mutational frequency and spectrum were determined for 95 carcinomas of the upper and lower respiratory tract (32 lung and 63 upper respiratory tract). Mutations were identified at a frequency of 30% in upper respiratory tract (URT) tumors and 31% in lung tumors. All 29 identified mutations were single-base substitutions. Comparison of the frequency of specific base substitutions between lung and URT showed a striking difference. Transitions occurred at a frequency of 68% in URT, but only 30% in lung. Mutations involving G:C-->A:T transitions, which are commonly reported in gastric and esophageal tumors, were the most frequently identified alteration in URT (11/19). Mutations involving G:C-->T:A transversions, which were relatively common in lung tumors (3/10) and are representative of tobacco smoke-induced mutations were rare in URT tumors (1/19). Interestingly, G:C-->A:T mutations at CpG sites, which are characteristic of endogenous processes, were observed frequently in URT tumors (9/19) but only rarely in lung tumors (1/10), suggesting that both endogenous and exogenous factors are responsible for the observed differences in mutational spectra between the upper and lower respiratory systems.

Natural killer (NK) cells as effectors of antibody-dependent cytotoxicity with chimeric antibodies reactive with human squamous-cell carcinomas of the head and neck

In patients with cancer, antibody-dependent cellular cytotoxicity (ADCC) may be used as a laboratory test or for enhancing immunotherapy with murine monoclonal or chimeric mouse/human anti-tumor antibodies (mMAbs or cMAbs, respectively). We have established an ADCC assay with IgG1 cMAb SF-25, using human squamous-cell carcinoma of the head and neck (SCCHN) cell lines as targets. By flow cytometry, all SCCHN cell lines tested expressed the antigen recognized by cMAb SF-25. Trypsinization of the cell monolayers facilitated binding of cMAb SF-25 to the antigen on the cell surface of SCCHN targets. Using the PCI-50 SCCHN cell line as a target coated with this cMAb at the optimal concentration of 1.0 micrograms/ml, normal human peripheral blood mononuclear cells (PBMC, n = 28) were found to mediate ADCC at a mean level of 283 +/- 42 (SEM) lytic units (LU20/10(7) effector cells). Non-adherent monocyte-depleted PBMC and natural killer (NK) cells purified by negative selection mediated significantly higher levels of ADCC than unseparated PBMC against SCCHN targets. NK cells, defined as CD3-CD56+ cells, could be effectively armed by cMAb SF-25, as confirmed by flow cytometry and ADCC assays. IL2-activated armed NK cells mediated higher levels of ADCC than non-armed NK cells. Binding of cMAb SF-25 to NK cells and their ADCC were enhanced by pre-incubation with polyethylene glycol. Arming of NK cells with chimeric antibodies should be considered in developing novel strategies for treatment of human SCCHN, especially in the adjuvant setting.