Imaging findings of head and neck dermatofibrosarcoma protuberans

BACKGROUND AND PURPOSE

Dermatofibrosarcoma protuberans is a rare, locally aggressive sarcoma of the skin in children and adults, usually involving the trunk and extremities and less commonly the head and neck. Despite clinical reports in the literature on the management of dermatofibrosarcoma protuberans, there are limited articles describing its imaging features.

MATERIALS AND METHODS

We retrospectively reviewed the demographics and imaging findings in all 24 patients with pathologically proven dermatofibrosarcoma protuberans of the head and neck seen at a tertiary cancer center between 2001 and 2010.

RESULTS

Twenty-two of the 24 lesions were nodular and well circumscribed; 19 of the 24 were located on the scalp. On imaging, all 24 lesions involved subcutaneous tissues. The lesions ranged in size from 0.6-9.5 cm (mean, 3.7 cm; standard deviation, 2.3 cm). Twelve lesions involved the soft tissues either at or extending directly to the midline. Thirteen lesions were associated with bulging of the skin surface. Fourteen lesions were imaged with CT and 14 with MR imaging. Whereas variable enhancement patterns were noted on CT and MR imaging, dermatofibrosarcoma protuberans was usually T2-hyperintense and demonstrated marked enhancement. None of the lesions was associated with bone invasion, perineural spread, or nodal/distant metastasis.

CONCLUSIONS

Knowledge of the imaging characteristics of dermatofibrosarcoma protuberans may alert neuroradiologists to include dermatofibrosarcoma protuberans in the differential diagnosis of lesions about the head and neck with similar imaging characteristics.

Loss of epithelial p53 and αv integrin cooperate through Akt to induce squamous cell carcinoma yet prevent remodeling of the tumor microenvironment

Most of the squamous cell carcinomas (SCCs) of the skin and head and neck contain p53 mutations. The presence of p53 mutations in premalignant lesions suggests that they represent early events during tumor progression and additional alterations may be required for SCC development. Here we show that co-deletion of the p53 and αv integrin genes in mouse stratified epithelia induced SCCs in 100% of the mice, more frequently and with much shorter latency than deletion of either gene alone. The SCCs that lacked p53 and αv in the epithelial tumor cells exhibited high Akt activity, lacked multiple types of infiltrating immune cells, contained a defective vasculature, and grew slower than tumors that expressed p53 or αv. These results reveal that loss of αv in epithelial cells that lack p53 promotes SCC development, but also prevents remodeling of the tumor microenvironment and delays tumor growth. We observed that Akt inactivation in SCC cells that lack p53 and αv promoted anoikis. Thus, tumors may arise in these mice as a result of the increased cell survival induced by Akt activation triggered by loss of αv and p53, and by the defective recruitment of immune cells to these tumors, which may allow immune evasion. However, the defective vasculature and lack of a supportive stroma create a restrictive microenvironment in these SCCs that slows their growth. These mechanisms may underlie the rapid onset and slow growth of SCCs that lack p53 and αv.

Urban legends series: oral leukoplakia

To date, the term oral leukoplakia (OL) should be used to recognize 'predominantly white plaques of questionable risk, having excluded (other) known diseases or disorders that carry no increased risk of cancer'. In this review, we addressed four controversial topics regarding oral leukoplakias (OLs): (i) Do tobacco and alcohol cause OLs?, (ii) What percentage of OLs transform into oral squamous cell carcinoma (OSCC)?, (iii) Can we distinguish between premalignant and innocent OLs?, and (iv) Is proliferative verrucous leukoplakia (PVL) a specific entity or just a form of multifocal leukoplakia? Results of extensive literature search suggest that (i) no definitive evidence for direct causal relationship between smoked tobacco and alcohol as causative factors of OLs, (ii and iii) the vast majority of OLs follow a benign course and do not progress into a cancer, and no widely accepted and/or validated clinical and/or biological factors can predict malignant transformation, and (iv) the distinction between multifocal/multiple leukoplakias and PVL in their early presentation is impossible; the temporal clinical progression and the high rate of recurrences and development of cancer of PVL are the most reliable features for diagnosis.

TrkC signaling is activated in adenoid cystic carcinoma and requires NT-3 to stimulate invasive behavior

Treatment options for adenoid cystic carcinoma (ACC) of the salivary gland, a slowly growing tumor with propensity for neuroinvasion and late recurrence, are limited to surgery and radiotherapy. Based on expression analysis performed on clinical specimens of salivary cancers, we identified in ACC expression of the neurotrophin-3 receptor TrkC/NTRK3, neural crest marker SOX10, and other neurologic genes. Here, we characterize TrkC as a novel ACC marker, which was highly expressed in 17 out of 18 ACC primary-tumor specimens, but not in mucoepidermoid salivary carcinomas or head and neck squamous cell carcinoma. Expression of the TrkC ligand NT-3 and Tyr-phosphorylation of TrkC detected in our study suggested the existence of an autocrine signaling loop in ACC with potential therapeutic significance. NT-3 stimulation of U2OS cells with ectopic TrkC expression triggered TrkC phosphorylation and resulted in Ras, Erk 1/2 and Akt activation, as well as VEGFR1 phosphorylation. Without NT-3, TrkC remained unphosphorylated, stimulated accumulation of phospho-p53 and had opposite effects on p-Akt and p-Erk 1/2. NT-3 promoted motility, migration, invasion, soft-agar colony growth and cytoskeleton restructuring in TrkC-expressing U2OS cells. Immunohistochemical analysis demonstrated that TrkC-positive ACC specimens also show high expression of Bcl2, a Trk target regulated via Erk 1/2, in agreement with activation of the TrkC pathway in real tumors. In normal salivary gland tissue, both TrkC and Bcl2 were expressed in myoepithelial cells, suggesting a principal role for this cell lineage in the ACC origin and progression. Sub-micromolar concentrations of a novel potent Trk inhibitor AZD7451 completely blocked TrkC activation and associated tumorigenic behaviors. Pre-clinical studies on ACC tumors engrafted in mice showed efficacy and low toxicity of AZD7451, validating our in vitro data and stimulating more research into its clinical application. In summary, we describe in ACC a previously unrecognized pro-survival neurotrophin signaling pathway and link it with cancer progression.

Olfactory neuroblastoma and neuroendocrine carcinoma of the anterior skull base: treatment results at the m.d. Anderson cancer center

Updated information on the pathologic characterization and treatment of olfactory neurobiastoma (ON) and neuroendocrine carcinoma (NEC) diseases is presented. A series of patients with ON or NEC was evaluated and retrospectively staged using the UCLA system. The parameters evaluated were symptoms, age, sex, risk factor assessment, stage of disease, treatment, and clinical outcome. The median follow-up was 3 years (range, 18 months to 23 years). The predominant therapy (63%) for ON was combined surgery and radiotherapy. Surgery alone or in combination with ancillary treatment was used in 58% of patients with NEC. For the most receat years of the study, patients with NEC have been treated successfully with combined chemotherapy and radiotherapy. Seventy percent of the patients with ON and 75% of the patients with NEC were clinically free of disease during the defined follow-up period. Surgical therapy consisting of a craniofacial resection combined with postoperative radiotherapy has resulted in good local and long-term control of ON. Our experience indicates that combined chemoradiation is an appropriate therapeutic approach for NEC.

Enhanced MDM2 Oncoprotein Expression in Soft Tissue Sarcoma: Several Possible Regulatory Mechanisms

Purpose. MDM2 is an oncogene whose protein product may promote tumorigenesis by blocking wild-type p53 tumor suppressor mediated G ₀/G₁ cell cycle arrest, thereby inhibiting repair of damaged DNA prior to cell division. While MDM2 DNA amplification is frequently observed in human sarcoma, the mechanisms linking this amplification to MDM2 oncoprotein over-production as well as its functional significance have not been well characterized in patients with soft tissue sarcoma.

Methods. A tissue bank of resected soft tissue sarcomas and autologous normal tissues was assembled; all specimens were snap frozen within 15 min of resection. DNA and RNA were extracted from tissues using isoamyl alcohol and phenol chloroform extraction methods, respectively; cell lysates were prepared using PBSTDS lysis buffer. DNA and mRNA were confirmed as being non-degraded and were then examined for MDM2 DNA amplification (Southern blots) and mRNA over-expression (Northern blots) using actin (DNA) and glyceraldehyde-3-phosphate dehydrogenase (mRNA) as loading controls. The MDM2 protein was examined on Western blots using the MDM2-specific monoclonal antibody IF2 (Oncogene Science, Inc). The presence of p53 DNA and expression of p53 mRNA was examined by rehybridizing the Southern and Northern filters using a p53-specific cDNA probe.

Results. Soft tissue sarcomas and autologous normal tissues were screened for MDM2 DNA amplification, which was detected in 10 of 30 tumors screened. After screening, there was sufficient biomaterials from six specimens for subsequent Northern and Western analysis to see whether MDM2 gene amplification correlated with over-expression of MDM2 mRNA and MDM2 protein. In addition, we examined whether other mechanisms may lead to over-expression of the MDM2 oncoprotein. Several possible mechanisms of MDM2 oncoprotein over-expression were identified. These most commonly included MDM2 DNA amplification, MDM2 mRNA over-expression and MDM2 oncoprotein over-expression. However, some soft tissue sarcoma patient specimens had no evidence of MDM2 mRNA over-expression yet had MDM2 oncoprotein over-production in the tumor relative to autologous normal tissue, implying possible post-transcriptional regulation. Of functional relevance, MDM2 oncoprotein over-production by tumors was associated with large decreases in the percentage of cells in the ₀/G₁ cell cycle interface compared with autologous normal tissue cells.

Discussion. It is likely that there are multiple mechanisms underlying human soft tissue sarcoma MDM2 oncoprotein over-production. Consequently, strategies that decrease MDM2 over-production, such as transcriptional repression to inhibit MDM2 promoter activity or RNA antisense approaches, may ultimately offer the best therapeutic efficacy.

Gefitinib for advanced cutaneous squamous cell carcinoma of head and neck: Phase II trial

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Background: Advanced head and neck cutaneous squamous cell carcinoma (HN cSCC) carries a 30–40% risk of death by 2 years with standard therapies. Small molecular inhibitors of the epidermal growth factor receptor (EGFR) may have an impact. We evaluated gefitinib as an induction therapy in a high-risk patient (pt) group prior to definitive therapy to determine efficacy, toxicity and feasibility. Correlative studies of EGFR expression, gene mutation, and ploidy may serve as predictors of response. Methods: Eligible pts must have HN cSCC >2cm, regional nodal metastases, peri-neural invasion, or deep invasion and must be candidates for definitive locoregional therapy with surgery and/or radiation. Two 30-day induction cycles of gefitinib (250mg po qd). Pts are assessed clinically after 15 days. If a response is noted, gefitinib is continued. For pts with stable disease, the dose is escalated to 500mg qd. Pts with progressive disease go off study. Total and phosphorylated (p) EGFR protein expression was analyzed by immunohistochemistry and gene copy number by fluorescent in-situ hybridization (FISH). Results: To date, 23 pts are enrolled and 22 are evaluable for responses and toxicities. Complete responses (CR) were noted in 3 pts, partial response (PR) 7, stable disease (SD) 5, and progressive disease (PD) 7 (68.1% response per RECIST criteria). Minimal side effects are associated with gefitinib (cutaneous and GI related). EGFR and p-EGFR protein overexpression were observed in 5 of 11 (45.5%) pts tested thus far. Eight of the pts were FISH negative with respect to EGFR gene expression: 7 had low trisomy and 1 had low polysomy. Two were FISH positive and expressed high polysomy. No gene amplification was detected. No statistically significant correlations between EGFR gene or protein expression and responses to administration of gefitinib were found at this point in the analysis. Protein and gene expression analyses are ongoing. Conclusions: The preliminary results from our study are encouraging and suggest that anti-EGFR therapy may have a role in the adjuvant treatment of HN cSCC. Correlative studies may help identify pts most likely to respond to anti-EGFR therapy.

No significant financial relationships to disclose.

Association between human papillomavirus (HPV) status with serum cytokine and angiogenic factor (CAF) profile after induction chemotherapy in head and neck squamous cell carcinoma (HNSCC)

6081

Background: Human papillomavirus has been implicated in the development of head and neck squamous cell carcinoma and is associated with a more favorable clinical outcome. Previously, we identified a serum hypoxia signature associated with HNSCC progression (Byers et al, Proc ASCO. 2008). We investigated the association between HPV status, serum biomarkers, and clinical outcome in patients treated with induction chemotherapy. Methods: 47 previously untreated patients with locally advanced nodal disease (T0–4, N2b/c/3, M0) received 6 weekly cycles of paclitaxel (135 mg/m2), carboplatin (AUC 2), and cetuximab (400 mg/m2 week 1; 250 mg/m2 weeks 2–6) followed by definitive local therapy. 46 (98%) patients had a complete or partial response to induction chemotherapy (Kies et al, Proc ASCO. 2006), and 6 have had tumor progression (PD) after a minimum follow-up of two years. Formalin fixed biopsies were available for HPV testing by in situ hybridization with non-radioisotopic chromogen for 25 patients (including 5/6 with PD). 38 CAFs were measured by multiplex bead assay before and during treatment. Results: 12/25 patients were HPV-positive, all male and six were never smokers; of the 13 HPV-negative patients, four were male and three were never smokers. Among those with available data, all 5 patients with PD were HPV-negative (p = 0.02). There were four study deaths, all in the HPV-negative group. Overall survival was superior in HPV-positive patients (p = 0.04). There was no significant association between HPV status and serum CAF markers. However, among HPV-negative patients, PD was associated with the CAF hypoxia signature (5/8 patients with the hypoxia signature progressed versus 0/5 signature-negative). Of the individual CAFs, osteopontin was significantly elevated in all HPV-negative patients with PD. Conclusions: HPV positivity was associated with a longer progression-free survival and overall survival. Among HPV-negative patients, only those with a serum hypoxia signature had disease progression. These data suggest that the combination of HPV status and CAF profiling may identify patients at risk for relapse after sequential therapy.

No significant financial relationships to disclose.

Correlation of Src activation with epithelial-mesenchymal transformation and aggressive features of head and neck squamous carcinoma

6026

Background: The role of the epithelial-mesenchymal transition (EMT) is crucial to invasive and progression of several epithelial malignancies. The role of this process in head and neck squamous cell carcinoma (HNSCC) remains poorly defined. Methods: Eleven head and neck squamous cancer cell lines and 50 primary tumor specimens formed the materials for this study. We used Western blotting, immunohistochemistry, RT-PCR cell motility assay to determine the expression and the functional implications of several cell adhesions and singling molecular associated with EMT in these tumors. Results: Our results showed Src and E-Cadherin to be paradoxically overexpressed in the majority of cell lines and in primary tumor tissues relative to normal squamous mucosa. In both cell lines and tumor tissues elevation of activated Src was accompanied by down-regulation of E-Cadherin and vimentin detection. In-vitro inhibition of Src led to the increased E-Cadherin of expression and cell proliferation in squamous carcinoma cell lines. Immunophenotypic analysis of the protein products of these genes in primary tumor tissues demonstrated a spectrum of changes that correlated significantly with the differentiation, invasive patterns, sarcomatoid transformation and lymph node status. Our results show that high activated Src and low E-Cadherin expression were correlated with finger-like invasive pattern, poor differentiation, sarcomatoid transformation and lymph node metastasis in HNSC. Conclusions: Our study indicates that Src and E-Cadherin play a major role in EMT invasion and progression of head and neck squamous carcinoma. These proteins may be targeted in the therapeutic intervention of patients with HNSCC.

No significant financial relationships to disclose.

A genetic mouse model for metastatic lung cancer with gender differences in survival

Lung cancer is a devastating disease with poor prognosis. The design of better therapies for lung cancer patients would be greatly aided by good mouse models that closely resemble the human disease. Unfortunately, current models for lung adenocarcinoma are inadequate due to the absence of metastases. In this study, we incorporated both K-ras and p53 missense mutations into the mouse genome and established a more faithful genetic model for human lung adenocarcinoma, the most common type of lung cancer. Mice with both mutations developed advanced lung adenocarcinomas that were highly aggressive and metastasized to multiple intrathoracic and extrathoracic sites in a pattern similar to that of human lung cancer. These mice also showed a gender difference in cancer-related death. Additionally, the presence of both mutations induced pleural mesotheliomas in 23% of these mice. This mouse model recapitulates the metastatic nature of human lung cancer and will be invaluable to further probe the molecular basis of metastatic lung cancer and for translational studies.

Induction chemotherapy (CT) with weekly paclitaxel, carboplatin, and cetuximab for squamous cell carcinoma of the head and neck (HN)

5520

Background: To further determine the potential efficacy of combining cetuximab with chemotherapy, we conducted a phase II trial with induction CT consisting of 6 weekly cycles of paclitaxel 135 mg/m2, carboplatin auc 2 and cetuximab 400 mg/m2 week 1 then 250 mg/m2 weekly. Methods: Patients (pts) were treatment-naïve with staging T0–4, N2b/c/3, M0; PS 0/1; with any HN primary site; and evaluated for clinico-radiographic complete response (CR). Pathway signaling biomarkers and genomic profiling are planned. Following CT, patients underwent “risk-based” local therapy. Choice of surgery ± postoperative radiotherapy (RT), RT, or concomitant chemoRT was based upon tumor stage and site at diagnosis. Results: Patient entry (2/05–11/05) has concluded with 47 patients (33 m, 14 f), median age 53 years and range 21–78. Two patients are too early for response analysis. Oropharynx was the dominant primary site, N = 42, with staging: Tx N2b - 4, Tx N3 - 1; T1 N2b - 5, T1 N2c - 6, T1 N3 - 3; T2 Nx - 1, T2 N2b - 10, T2 N3 - 3; T3 N2b - 5, T3 N2c - 3, T3 N3 - 1; T4 N2b - 2 and T4 N2c - 3. Toxicity was acceptable. Sixteen (34%) pts had grade 3/4 leukopenia; 22 (47%) grade 3 folliculitis (median 5 cycles of cetuximab administered); and 2 (4%) serious hypersensitivity. All 41 evaluable pts achieved a response in the primary site, 7 (17%) PR and 34 (83%) CR. Forty-three of 44 evaluable patients achieved a nodal response, 31 (70%) PR and 12 (27%) CR. Overall, 11 of 45 (24%) pts were disease-free after CT. At this early point, 3 pts have had 4 tumor recurrences, 2 local and 2 distant. Conclusions: CT administered over 6 wks, with cetuximab, was feasible and highly active with all patients achieving a tumor response. Severe skin rash affected nearly 50% of pts. Preliminary survival data, and correlation of surrogate biomarkers with tumor response are to be presented. Supported by: Bristol Myers Squibb Oncology and Imclone Systems Grant #CS 2004–00011435 WC.

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ICAM-5 (telencephalin) gene expression in head and neck squamous carcinoma tumorigenesis and perineural invasion!

ICAM-5 (telencephalin) is an intercellular adhesion molecule reported to be expressed only in the somatodendritic membrane of telencephalic neurons. We recently identified high ICAM-5 expression in a cDNA array study of head and neck neoplasms with a propensity for perineural invasion. To determine the association of this gene in tumorigenesis and perineural invasion, we analyzed the expression and functional status of ICAM-5 mRNA transcripts in 30 different human cancer cell lines and 25 head and neck squamous carcinoma specimens by reverse-transcriptase polymerase chain reaction (cell lines and specimens) and in vitro functional assays (cell lines). ICAM-5 transcripts were detected in 28 (93%) of 30 cell lines derived from primary head and neck, colon, thyroid, cervical, pancreatic, skin, and adenoid cystic carcinomas. In cell lines, small interfering RNA blocked ICAM-5 expression and inhibited cell proliferation. Treatment with the phosphatidylinositol 3'-kinase (PBK) inhibitor LY294002 resulted in ICAM-5 down-regulation. In tissue specimens, none of the 25 histologically normal oral mucosal specimens had detectable ICAM-5 level, whereas 16 (64%) of the 25 matched primary squamous carcinomas showed expression. Carcinoma specimens high ICAM-5 expression had a high incidence of perineural invasion. Our study indicates that ICAM-5 may play a role in tumorigenesis and perineural invasion, most likely through the P13K/Akt-signaling pathway.

The Akt inhibitor KP372-1 suppresses Akt activity and cell proliferation and induces apoptosis in thyroid cancer cells

The phosphatidylinositol 3′ kinase (PI3K)/phosphatase and tensin homologue deleted on chromosome ten/Akt pathway, which is a critical regulator of cell proliferation and survival, is mutated or activated in a wide variety of cancers. Akt appears to be a key central node in this pathway and thus is an attractive target for targeted molecular therapy. We demonstrated that Akt is highly phosphorylated in thyroid cancer cell lines and human thyroid cancer specimens, and hypothesised that KP372-1, an Akt inhibitor, would block signalling through the PI3K pathway and inhibit cell proliferation while inducing apoptosis of thyroid cancer cells. KP372-1 blocked signalling downstream of Akt in thyroid tumour cells, leading to inhibition of cell proliferation and increased apoptosis. As thyroid cancer consistently expresses phosphorylated Akt and KP372-1 effectively blocks Akt signalling, further preclinical evaluation of this compound for treatment of thyroid cancer is warranted.

Detection and diagnosis of oral neoplasia with an optical coherence microscope

The use of high resolution, in vivo optical imaging may offer a clinically useful adjunct to standard histopathologic techniques. A pilot study was performed to investigate the diagnostic capabilities of optical coherence microscopy (OCM) to discriminate between normal and abnormal oral tissue. Our objective is to determine whether OCM, a technique combining the subcellular resolution of confocal microscopy with the coherence gating and heterodyne detection of optical coherence tomography, has the same ability as confocal microscopy to detect morphological changes present in precancers of the epithelium while providing superior penetration depths. We report our results using OCM to characterize the features of normal and neoplastic oral mucosa excised from 13 subjects. Specifically, we use optical coherence and confocal microscopic images obtained from human oral biopsy specimens at various depths from the mucosal surface to examine the optical properties that distinguish normal and neoplastic oral mucosa. An analysis of penetration depths achieved by the OCM and its associated confocal arm found that the OCM consistently imaged more deeply. Extraction of scattering coefficients from reflected nuclear intensity is successful in nonhyperkeratotic layers and shows differentiation between scattering properties of normal and dysplastic epithelium and invasive cancer.

Limitations of size as a criterion in evaluating adrenal tumours

Background

Size is considered the single best predictor of malignancy in evaluating adrenal neoplasms identified incidentally during abdominal imaging, yet small adrenal cortical cancers have been reported previously from several centres.

Methods

This was a retrospective evaluation of the value of tumour size and other preoperative clinical parameters in predicting the presence or absence of malignancy in adult patients who underwent adrenalectomy for an adrenal tumour at this institution.

Results

One hundred and sixteen patients underwent adrenalectomy. Diagnoses were adrenal cortical carcinoma (n = 38), phaeochromocytoma (n = 27), metastasis to the adrenal gland (n = 11) and benign tumours (n = 40) (cortical adenoma, 23; cyst, two; cortical hyperplasia, five; ganglioneuroma, four; myelolipoma, six). The median size of the adrenal cortical carcinomas was 9·2 (range 1·7–30) cm; five tumours were smaller than 5·0 cm. The median overall size of the benign tumours (excluding phaeochromocytomas) was 4·0 cm; the median size of the adrenal cortical adenomas was 3·0 cm. Eleven benign tumours were larger than 5·0 cm, including two cortical adenomas. The radiographic features of three of five small adrenal cancers correctly predicted malignancy; the remaining two patients with small cancers had symptoms related to functioning tumours. Conversely, the radiographic features of seven of 11 large benign adrenal tumours correctly predicted benign histology, including five of five myelolipomas.

Conclusion

While size remains a good predictor of histology and clinical behaviour of functioning and non-functioning adrenal neoplasms, both small adrenal cortical cancers and large benign tumours occur with measurable frequency. High-quality imaging studies (computed tomography and magnetic resonance imaging) may be helpful in identifying relatively small yet radiographically atypical adrenal tumours more likely to be cancers, as well as radiographically characteristic benign myelolipomas which may be followed selectively.

Phase II study of the antiangiogenesis agent thalidomide in recurrent or metastatic squamous cell carcinoma of the head and neck

BACKGROUND

Thalidomide has been shown to have antiangiogenic effects in preclinical models as well as a significant antitumor effect in hematologic tumors such as multiple myeloma. The authors performed this Phase II study to determine the activity, toxicity profile, and antiangiogenic effect of thalidomide in patients with locoregionally recurrent or metastatic squamous cell carcinoma of the head and neck.

METHODS

Twenty-one patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with single-agent thalidomide. All patients had received radiation therapy, and most had undergone surgery (95%) and/or chemotherapy (90%). Thalidomide was initiated at 200 mg;3>daily and increased to a target dose of 1000 mg daily. Patients continued treatment until disease progression, unacceptable toxicity, or death occurred.

RESULTS

All 21 patients eventually developed progressive disease. Median time to progression was 50 days (95% confidence interval, 28-70), with median overall survival time of 194 days (95% lower confidence boundary, 151), similar to the progression and survival times reported for this patient group with other agents. Thalidomide was generally well tolerated, with few patients experiencing Grades 3 to 4 toxicities. Serum vascular endothelial growth factor and basic fibroblast growth factor levels increased in six of seven patients, for whom paired serum samples were available and all of whom had progressive disease.

CONCLUSIONS

In this heavily pretreated population of patients with advanced squamous cell carcinoma of the head and neck, thalidomide does not appear to have single-agent antitumor activity. Further evaluation of the mechanism of action of thalidomide is indicated. Potentially, future evaluations of thalidomide may be performed in combination with other antiangiogenic or cytotoxic agents in patients with earlier stage disease or in patients with minimal residual disease.

Loss of PTEN expression as a prognostic marker for tongue cancer

BACKGROUND

Abnormalities of PTEN, a candidate tumor suppressor gene located at 10q23.3, play an important role in the tumorigenesis of multiple tumor types.

OBJECTIVES

To investigate the expression of PTEN and its clinical implication in squamous cell carcinoma of the tongue.

DESIGN

Retrospective analysis of PTEN protein expression in archived primary oral tongue tumor samples.

SETTING

Academic center.

PATIENTS AND METHODS

PTEN expression was determined by immunohistochemical analysis in tissue samples from 41 patients with stage II, III, and IV squamous cell carcinoma of the tongue. All the patients underwent curative surgical treatment with a median follow-up of 81 months. The Kaplan-Meier method was used for survival analysis. Multivariate analysis was performed according to the Cox proportional hazards model.

RESULTS

Lack of staining for PTEN was demonstrated in 12 (29%) of the 41 tumors. Patients whose tumors lacked PTEN expression had a significantly shorter overall survival time (P = .03) and event-free survival time (P = .01) than those patients with positive PTEN expression. Multivariate regression analysis demonstrated that PTEN expression is an independent predictor of poor outcome when compared with tumor stage and nodal status.

CONCLUSIONS

Although genetic alterations of the PTEN gene are rare in head and neck squamous cell carcinoma, loss of PTEN is not an uncommon event in squamous cell carcinoma of the tongue. Lack of PTEN expression may be an independent prognostic indicator for clinical outcome in patients with this tumor type.

Phase II study of the antiangiogenesis agent thalidomide in recurrent or metastatic squamous cell carcinoma of the head and neck

BACKGROUND

Thalidomide has been shown to have antiangiogenic effects in preclinical models as well as a significant antitumor effect in hematologic tumors such as multiple myeloma. The authors performed this Phase II study to determine the activity, toxicity profile, and antiangiogenic effect of thalidomide in patients with locoregionally recurrent or metastatic squamous cell carcinoma of the head and neck.

METHODS

Twenty-one patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with single-agent thalidomide. All patients had received radiation therapy, and most had undergone surgery (95%) and/or chemotherapy (90%). Thalidomide was initiated at 200 mg;3>daily and increased to a target dose of 1000 mg daily. Patients continued treatment until disease progression, unacceptable toxicity, or death occurred.

RESULTS

All 21 patients eventually developed progressive disease. Median time to progression was 50 days (95% confidence interval, 28-70), with median overall survival time of 194 days (95% lower confidence boundary, 151), similar to the progression and survival times reported for this patient group with other agents. Thalidomide was generally well tolerated, with few patients experiencing Grades 3 to 4 toxicities. Serum vascular endothelial growth factor and basic fibroblast growth factor levels increased in six of seven patients, for whom paired serum samples were available and all of whom had progressive disease.

CONCLUSIONS

In this heavily pretreated population of patients with advanced squamous cell carcinoma of the head and neck, thalidomide does not appear to have single-agent antitumor activity. Further evaluation of the mechanism of action of thalidomide is indicated. Potentially, future evaluations of thalidomide may be performed in combination with other antiangiogenic or cytotoxic agents in patients with earlier stage disease or in patients with minimal residual disease.

Genetic heterogeneity in saliva from patients with oral squamous carcinomas: implications in molecular diagnosis and screening

We performed microsatellite analysis at chromosomal regions frequently altered in head and neck squamous carcinoma on matched saliva and tumor samples from 37 patients who had oral squamous carcinoma. The results were correlated with the cytologic findings and traditional clinicopathologic factors to assess the diagnostic and biological potential of these markers. Our data showed that 18 (49%) of the saliva samples and 32 (86%) of the tumors had loss of heterozygosity (LOH) in at least one of the 25 markers studied. In saliva, the combination of markers D3S1234, D9S156, and D17S799 identified 13 (72.2%) of the 18 patients with LOH in saliva (P < 0.001). For tumors, markers D3S1234, D8S254, and D9S171 together identified 27 (84.3%) of the 32 tumors with LOH at any of the loci tested (P < 0.001). Eleven (55%) of the 20 saliva samples with cytologic atypia and seven (35%) of the 17 specimens without atypia had LOH. Significant correlation between LOH in tumor at certain markers and smoking and alcohol use was found. Our results indicate that: 1) epithelial cells in saliva from patients with head and neck squamous tumorigenesis provide suitable material for genetic analysis; 2) combined application of certain markers improves the detection of genetic alteration in these patients; 3) clonal heterogeneity between saliva and matching tumor supports genetic instability of the mucosal field in some of these patients; and 4) LOH at certain chromosomal loci appears to be associated with smoking and alcohol consumption.

Molecular and biomarker analyses of salivary duct carcinomas: comparison with mammary duct carcinoma

Salivary duct carcinoma (SDC) is a rare high-grade aggressive neoplasm that manifests close histologic features with invasive ductal carcinoma of the breast (IDC). In contrast to SDC, extensive molecular studies have been performed on IDC and led to the identification of certain biological markers. To investigate the underlying molecular and biologic characteristics of SDC, we performed molecular analyses using microsatellite markers on chromosomal arms 6q, 16q, 17p, and 17q, DNA flow cytometry and immunohistochemical staining for androgen receptor (AR) and p53 expression on 28 examples of these tumors in comparison to 24 IDC cases. Our results show that generally similar allelic alterations, elevated p53 and androgen receptor expressions, and high frequency of DNA aneuploidy are manifested in both SDCs and IDCs. Differences at certain markers on 6q, 17p and 17q chromosomal loci, however, were observed between the two entities. Certain loci on 6q were more frequently altered in SDC than IDC which loci on chromosomes 17p and q arms were more seen in IDCs than SDCs. The majority of SDCs had high AR expression while most of IDCs were AR negative. Our study indicates that: i) SDC may share some genetic alterations with IDC, ii) high AR expression in SDC may play a role in tumor progression, and iii) p53 overexpression and DNA aneuploidy in both entities reflect their aggressive behavior.

UV irradiation augments lymphoid malignancies in mice with one functional copy of wild-type p53

Epidemiological studies have suggested an association between exposure to solar UV radiation and the incidence of lymphoid malignancies, which has increased substantially worldwide during the last two decades. Findings from animal studies have raised the question of whether UV radiation might influence the development of lymphoid malignancies by means of its immunosuppressive effect. In this study, we examined the effect of UV irradiation on the development of lymphoid malignancies in mice with no or only one functional copy of p53. Mice that lack both copies of p53 spontaneously develop high frequency of lymphoid malignancies in the thymus and spleen. p53 heterozygous mice with only one copy of the wild-type allele also develop lymphoid malignancies, but with a much lower frequency and a long latent period. In our study using mice of the C57BL/6 background, only one of the unirradiated mice lacking one copy of p53 (p53(+/-)) spontaneously developed a lymphoid tumor (6%), whereas 88% of UV-irradiated p53(+/-) mice developed lymphoid tumors in the spleen or liver. None of the control or UV-irradiated p53 wild-type mice developed lymphoid tumors during the 60-week observation period. Both UV-irradiated and unirradiated mice lacking both copies of p53 (p53(-/-)) rapidly developed thymic lymphomas and/or lymphoid tumors in spleen or liver. All of the lymphoid tumors tested were of T cell type. The immune responses of the mice to contact sensitization were identical and were suppressed to the same extent by UV irradiation regardless of the genotype. These results indicate that differences in immune reactivity do not account for the different effects of UV radiation on lymphoid malignancies and, in addition, that p53 is not required for generation of T cell-mediated immunity. Interestingly, whereas p53 mutations or loss of heterozygosity did not account for the accelerated development of lymphoid tumors in UV-irradiated p53(+/-) mice, deletions in the p16(INK4a) gene were quite common. These data provide the experimental evidence that UV irradiation induces lymphoid neoplasms in genetically susceptible mice and support the hypothesis that extensive sunlight exposure contributes to the induction of lymphoma in humans.

Clinical significance of cyclin B1 protein expression in squamous cell carcinoma of the tongue

PURPOSE

Cyclin B1 plays an important role in control of the G(2)-M transition of the cell cycle. We have shown recently that overexpression of cyclin B1 is associated with poor outcome in patients with early stage squamous cell carcinoma (SCC) of the lung.

EXPERIMENTAL DESIGN

To determine the role of cyclin B1 in SCC of the tongue, we analyzed tumor specimens from 41 patients with stage II-IV SCC of the tongue who underwent curative surgery using immunohistochemistry.

RESULTS

The median follow-up of all patients was 83 months. Overexpression of cyclin B1 was observed in 15 (37%) of the 41 tumors, a similar frequency to that found in SCC of the lung. Patients whose tumors showed overexpression of cyclin B1 had a poor event-free survival compared with those lacking this feature (P = 0.04 by Log-rank test). Multivariate analysis of traditional clinical/pathological factors showed that cyclin B1 overexpression was an independent prognostic indicator.

CONCLUSIONS

Our study indicates that cyclin B1 is overexpressed in a subset of SCC of the tongue and is associated with a more aggressive biological behavior of the disease.

An alternatively spliced HDM2 product increases p53 activity by inhibiting HDM2

The human counterpart hdm2 of the murine double-minute 2 (mdm2) gene encodes a 90-kD protein (HDM2) that inhibits the function of the p53 tumor suppressor. Hdm2 is amplified in approximately 30% of sarcomas, leading to overproduction of HDM2 and inactivation of p53. Using immunohistochemistry to screen a panel of human tumors for HDM2 overproduction, we detected high levels of HDM2 in the cytoplasm in 25% of lung tumors as opposed to its normal localization in the nucleus. These samples contained full-length hdm2 and several alternate-splice forms of hdm2 mRNA. Sequence analysis revealed deletions in the alternate-splice forms of the p53 binding domain and absence of a nuclear localization signal. In transient transfection assays, one of the alternate-splice forms, HDM2(ALT1), bound and sequestered full-length HDM2 in the cytoplasm. In addition, the binding of HDM2(ALT1) to HDM2 inhibited the interaction of HDM2 with p53, thus enhancing p53 transcriptional activity. These data suggest the existence of another level of regulation of HDM2 which increases the activity of p53.

Comparative image and flow cytometric TUNEL analysis of fine needle samples of breast carcinoma

The assessment of apoptosis in solid tumors is of interest because of its biological role in tumor evolution and response to therapy. A commonly used method for apoptosis measurement is the TUNEL 3' end-labeling technique, which has shown wide variations in results when applied to solid tumors. Thirty-one fine needle breast carcinoma samples were analyzed by fluorescent TUNEL assay and DNA content using image analysis and flow cytometry. TUNEL positivity, seen both in cells with apoptotic morphology and in a subset of morphologically normal cells, was categorized into five staining patterns and quantitated. Values for patterns of TUNEL-positive cells were compared with TUNEL positivity measured by flow cytometry. Flow cytometric quantitation showed a mean of 24.3% positive cells, which correlated (P < 0.02) with total positive cells (all patterns) measured by image (22.4%). Image analysis quantitation of morphologically apoptotic cells (4.2%) did not correlate with flow cytometric TUNEL positivity and the majority of TUNEL-stained cells were morphologically normal (17%). Image analysis allows discrimination of TUNEL-positive morphologically apoptotic and nonapoptotic cells, which are included in the total number of TUNEL-positive events measured by flow cytometry.

p73 gene alterations and expression in primary oral and laryngeal squamous carcinomas

p73, a recently identified gene, maps to chromosome region 1p36.3, which is frequently deleted in a variety of solid tumors. Although the gene shares sequence and functional homologies with p53, its suppressor function has not been proven. We investigated for the first time the genetic and expression status of the p73 gene and analyzed its flanking microsatellite loci on chromosome 1p36.3 in 67 primary oral and laryngeal squamous cell carcinomas to determine their association with these tumors. Our results reveal two missense mutations at codons 469 and 477 and a silent mutation at codon 349 in the C-terminal domain. Site-directed mutagenesis of p73 cDNA with these mutations and a p21 transactivation assay failed to show any significant functional consequences of these mutations. Microsatellite analysis of the flanking loci of p73 in region 1p36 showed overall alterations (loss of heterozygosity and instability) frequency of 39%, 16% at the proximal marker and 46% at the distal markers. Of the 21 cases for which we did protein expression analyses, 11 tumors had a >2-fold variation compared with matching histologically normal mucosa. Our study shows that: (i) intragenic alterations in this gene are rare and lack functional significance; (ii) its variable expression argues against a tumor suppressor function; (iii) this gene plays a minor role in head and neck squamous carcinoma; (iv) a distal site to this gene on 1p36 may harbor another suppressor gene.

Malignant melanoma arising within a burn scar case report and review of the literature

Burn scar carcinomas, also called Marjolin's ulcers, are uncommon tumors that arise from an antecedent burn. Most burn scar carcinomas are diagnosed about 30 years after the burn, and most are well-differentiated squamous cell carcinomas. We report a case in which a squamous cell carcinoma developed within a burn scar on the cheek and then a malignant melanoma arose within the burn scar after the squamous cell carcinoma had been excised. We also review the available literature on burn scar carcinoma, covering the demographics, pathogenesis, diagnosis, prognosis, and treatment of the disease. Given the multifocality of this disease process, we advocate aggressive resection of the entire burn scar, as well as the tumor, to prevent the development of further cancers within the wound.

Fine-needle sampling of primary neuroendocrine carcinomas of salivary glands: cytohistological correlations and clinical analysis

Fine-needle samplings of nine examples of primary neuroendocrine carcinoma of salivary glands were evaluated for their cytologic characteristics and were correlated with the corresponding histological sections. Consistent cytological findings were dispersed or loose clusters of poorly differentiated small- to intermediate-sized cells and occasional smudged nuclei. Mild to moderate nuclear pleomorphism, scant or absent cytoplasm, and nuclear molding were also observed. Rosette-like patterns and multinucleated cells were occasionally seen. Immunostaining of one recent case showed positivity for chromogranin and keratin. The differential diagnosis of primary and metastatic tumors with neuroendocrine features of the salivary glands is discussed.

Expression of bcr-abl mRNA in individual chronic myelogenous leukaemia cells as determined by in situ amplification

We present the results of a novel method developed for evaluation of in situ amplification, a molecular genetic method at the cellular level. Reverse transcription polymerase chain reaction (RT-PCR) was used to study bcr-abl transcript levels in individual cells from patients with chronic myelogenous leukaemia (CML). After hybridizing a fluorochrome-labelled probe to the cell-bound RT-PCR product, bcr-abl mRNA-positive cells were determined using image analysis. A dilution series of bcr-abl-positive BV173 into normal cells showed a good correlation between expected and actual values. In 25 CML samples, the percentage of in situ PCR-positive cells showed an excellent correlation with cytogenetic results (r = 0.94, P < 0.0001), interphase fluorescence in situ hybridization (FISH) (r = 0.95, P = 0.001) and hypermetaphase FISH (r = 0.81, P < 0.001). The fluorescence intensity was higher in residual CML cells after interferon (IFN) treatment than in newly diagnosed patients (P = 0.004), and was highest in late-stage CML resistant to IFN therapy and lowest in CML blast crisis (P = 0.001). Mean fluorescence values correlated with bcr-abl protein levels, as determined by Western blot analysis (r = 0.62). Laser scanning cytometry allowing automated analysis of large numbers of cells confirmed the results. Thus, fluorescence in situ PCR provides a novel and quantitative approach for monitoring tumour load and bcr-abl transcript levels in CML.

Expression levels of genes that regulate metastasis and angiogenesis correlate with advanced pathological stage of renal cell carcinoma

We examined the expression levels of a number of metastasis-related genes to determine the relationship of these levels to the development of metastasis in renal cell carcinoma. Gene expression was examined in 46 formalin-fixed, paraffin-embedded, archival specimens of primary organ-confined, clear-cell, renal cell carcinoma from patients who had undergone radical nephrectomy. Twenty samples were from patients who did not have metastasis after a median of 48 months; 26 were from patients with either synchronous or metachronous metastases. Microvessel density was assessed by anti-CD-34 immunohistochemical analysis. The expression levels of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), matrix metalloproteinases (MMP)-2 and -9, and E-cadherin were examined at the periphery of the tumor by a colorimetric in situ mRNA. The expression levels of bFGF, VEGF, IL-8, MMP-2, and MMP-9 were significantly higher in primary renal tumors from patients with either synchronous or metachronous metastases than those who were disease-free at a median of 48 months of follow-up. Multivariate analysis of disease-free survival showed that the ratio of MMP-9 to E-cadherin (P = 0.012) and the expression level of bFGF expression (P = 0.045), were independent predictors for the development of metastases. The expression levels of bFGF, VEGF, and IL-8 did not correlate with microvessel density, which in itself was not a significant predictor of progression (P = 0.21). In summary, expression levels of genes that regulate metastasis angiogenesis can predict the metastatic potential in individual patients with organ-confined clear-cell renal carcinoma.

Limitations of size as a criterion in the evaluation of adrenal tumors

BACKGROUND

Size has been considered to be the single best predictor of malignancy in adrenal neoplasms that have been identified incidentally. However, small adrenal cortical cancers have been reported from multiple centers.

METHODS

We retrospectively evaluated the value of tumor size and other clinical parameters in the prediction of the presence of adrenal malignancy.

RESULTS

The records of 117 patients who underwent evaluation for tumors of the adrenal gland were reviewed. The median tumor size of the adrenal cortical carcinomas (n = 38 carcinomas) was 9.2 cm (range, 1.7-30 cm); 5 cancers (13.5%) were smaller than 5.0 cm. The median overall size of the benign tumors, excluding pheochromocytomas, was 4.0 cm (n = 38 carcinomas); 10 benign tumors (26%) were larger than 5.0 cm. The imaging features of 4 of 5 small adrenal cancers predicted malignancy; the remaining patients had hormonally functioning tumors. The imaging features of 7 of 10 large benign adrenal tumors predicted benign histologic features, including 5 of 5 myelolipomas.

CONCLUSIONS

Although size remains a good predictor of the histologic features and clinical behavior of adrenal neoplasms, both small adrenal cortical cancers and large benign tumors occur with measurable frequency. High-quality imaging studies may be helpful in the identification of relatively small adrenal cancers and of characteristic benign lesions that may be selectively followed.

Differential expression of Bax and Bcl-2 in the assessment of cellular dynamics in fine-needle samples of primary breast carcinomas

The rates of cell proliferation and programmed cell death (apoptosis) reflect tumor cell dynamics and are considered to directly influence biological progression and tumor response to therapy. Bax and Bcl-2 are members of a gene family that influence apoptosis and have been used as surrogate markers in the evaluation of this process. Sixty-three fine-needle tumor samples from an equal number of patients with breast carcinomas were analyzed for Bax, Bcl-2, and DNA content by flow cytometry. The results were correlated with classical clinicopathological parameters. Bax values varied widely among tumors and showed no significant correlation with any of the clinicopathological parameters analyzed. Bcl-2 levels ranged from 4% to 91%, correlated positively with estrogen (P = 0.0004) and progesterone (P = 0.0045) receptor positivity, and were more associated with low S-phase tumor values. In contrast, high S-phase values correlated with estrogen receptor negativity, high grade, and DNA aneuploidy. The study results indicate that Bcl-2 and S-phase analysis of fine-needle samples of breast carcinomas provide a convenient tool for the assessment of these tumors.

CGH analysis of radon-induced rat lung tumors indicates similarities with human lung cancers

Epidemiological studies have shown that inhalation of radon, a radioactive gas, is associated with an increased risk for lung cancer. We have developed a model of radon-induced rat lung tumors to characterize cytogenetic and molecular events involved in radon-induced lung tumorigenesis. Using comparative genomic hybridization (CGH), gains and losses of genetic material were investigated in a series of 13 carcinomas and four adenomas of the lung. Frequent losses occurred at 4q12-21, 5q11-33, and 15q, which are homologous to human chromosome (HSA) bands 7q21-36, 1p31-36/9p21-31, and 13q14.1-14.3/3p14.2, respectively. These regions are frequently (30-80%) deleted in human lung cancer and contain tumor suppressor genes or proto-oncogenes such as MET, CDKN2A/p16/MTS1, CDKN2B/p15/MTS2, FHIT, and RB1 or yet to be identified genes. Frequent gains involved 6, 7q34-qter, and 19q; chromosomes 6 and 7 being homologous to human 2p21-25 and 8q21-24 where the MYCN and MYC oncogenes are located. The genetic similarities between rat and human lung cancer suggest common underlying mechanisms for tumor evolution in both species. Moreover, cytogenetic and molecular genetic analyses of radon-induced rat lung tumors could help to better understand the development and progression of radon-induced lung cancer in man.

Expression of protein mediators of type I interferon signaling in human squamous cell carcinoma of the skin

IFN-based therapy has been shown to be active in the treatment of squamous cell carcinoma (SCC) of the skin and has promise for chemoprevention and treatment of several other cancers. In an effort to better understand the molecular mechanism of this activity, we have determined the expression pattern of several of the protein mediators of type I IFN signaling by immunohistochemistry in cutaneous SCC, SCC metastases, and adjacent nonmalignant epithelium from patient biopsies. All of the proteins, signal transducer and activator of transcription (STAT) 1alpha/beta, STAT2, p48, STAT3a, and STAT3beta, are expressed at varying levels in the adjacent epidermis, as well as in other epidermal and dermal cell types. For the majority of samples tested, the expression of one or more of these proteins was reduced in SCC primary tumors compared with the adjacent nonmalignant epithelial cells, as determined by manual scoring. Quantitative densitometry of several samples revealed differences that are statistically significant. Our study provides the first direct evidence for the expression of the IFN-stimulated gene factor 3 (STAT1alpha/beta, STAT2, and p48) and STAT3alpha and STAT3beta mediators of IFN-alpha/beta signaling in human skin and skin-derived SCCs. These data have led to the hypothesis that the loss of IFN sensitivity may contribute to the development and progression of skin SCC.

Loss of imprinting and genetic alterations of the cyclin-dependent kinase inhibitor p57KIP2 gene in head and neck squamous cell carcinoma

The p57KIP2 is a maternally expressed and paternally imprinted cyclin-dependent kinase inhibitor located on chromosome 11p15.5. Because of its location, biochemical functions, and imprinting status, p57KIP2 has been considered a candidate tumor suppressor gene. To determine, for the first time, the involvement of this gene in the development of head and neck squamous carcinoma (HNSC), we analyzed the imprinting and expression status and loss of heterozygosity (LOH) within the p57KIP2 gene flanking loci on the 11p15.5 region in 64 primary untreated tumors. Of the 30 (47%) informative cases for this gene, loss of imprinting and LOH were noted in 4 (13%) and 10 tumors (33%), respectively. Analysis of the microsatellite markers flanking the p57KIP2 gene on chromosome 11p showed infrequent alterations at these loci. p57KIP2 was expressed in all tumors with LOH within and around the gene. Quantitative reverse transcription-PCR analysis showed elevated p57 mRNA expression in tumor with loss of imprinting. Sequencing analysis of exons 1 and 2 of the p57KIP gene failed to detect any mutations. Our data indicate: (a) infrequent genomic abnormalities at the p57KIP2 gene in HNSC; (b) leaky or incomplete imprinting of the paternal allele is associated with increased expression of this gene in a subset of tumors; and (c) minimal evidence for suppressor function for this gene in HNSC.

Differential expression of galectin-1 and galectin-3 in benign and malignant salivary gland neoplasms

Galectins are a family of non-integrin beta-galactosidase-binding lectins. Altered expression of galectins has been associated with neoplastic transformation and progression in several human tumors. In this study, we examined the distribution patterns of galectin-1 and galectin-3 in normal (n=45), benign (n=16), and malignant (n=49) salivary gland specimens using immunohistochemistry to determine their diagnostic and/or biological implications in salivary gland tumorigenesis. In normal salivary glands, galectin-3 expression was limited to ductal cells, and galectin-1 was usually faintly detected in ductal cells and strongly positive in myoepithelial cells. In benign tumors, galectin-3 maintained the ductal localization, but galectin-1 showed variable expression in ductal and myoepithelial cells. In malignant tumors, most of the polymorphous low-grade adenocarcinomas and carcinoma ex-pleomorphic adenomas expressed both galectins, whereas adenoid cystic and acinic cell carcinomas showed dramatically reduced galectin-3 expression and heterogeneous galactin-1 staining. Our data demonstrated altered localization and expression of galectin-3, and to lesser extent, galectin-1 in salivary gland carcinomas. These findings may assist in the differential diagnosis of some salivary gland malignancies, especially when using small and limited fine-needle aspiration materials.

Expression of vascular endothelial growth factor and microvessel density in head and neck tumorigenesis

Angiogenesis is a fundamental process in tumor growth and metastasis, and its significance and that of vascular endothelial growth factor (VEGF) expression as prognostic indicators have been documented for various types of human tumors. However, the mechanisms responsible for angiogenesis in head and neck squamous cell carcinoma are not well defined. To examine the relationship between angiogenesis and the phenotypic progressions of head and neck tumorigenesis, we used immunohistochemistry to analyze VEGF expression and microvessel density in 70 paraffin-embedded specimens that contained adjacent normal epithelium, premalignant lesions, or both from 57 patients with head and neck squamous cell carcinoma. Ten samples of normal oral mucosa were obtained from people who did not smoke or drink alcohol and included in the analysis as normal controls. Microvessel density was evaluated by averaging 10 microscopic fields (x400) in a defined area of each specimen. The degree of VEGF expression was assessed on a cell-by-cell basis in 10 microscopic fields (x200) in a defined area on a scale ranging from 0 (no expression) to 3+ (highest level of expression). In addition, the weighted mean index of VEGF expression was calculated. The mean +/- SD weighted mean index of VEGF expression in normal control epithelium (1.10 +/- 0.38, n = 10) was higher than it was in adjacent normal epithelium (0.82 +/- 0.27, n = 13; P = 0.04). VEGF expression decreased as samples ranged from normal adjacent epithelium to hyperplasia (0.78 +/- 0.28, n = 21), mild dysplasia (0.70 +/- 0.29, n = 28), moderate dysplasia (0.67 +/- 0.29, n = 11), severe dysplasia (0.51 +/- 0.39, n = 6), and squamous cell carcinoma (0.20 +/- 0.27, n = 70; overall P = 0.0001). VEGF expression was two times lower in cases with nodal disease (0.17 +/- 0.26, n = 29) than it was in nonnodal disease (0.32 +/- 0.29, n = 16; P = 0.02). Microvessel density showed no significant difference from adjacent normal epithelium premalignant lesions to cancer. In tumor, no correlation was seen between VEGF expression or microvessel density and differentiation, primary tumor site, T stage, or smoking status. These findings indicate that VEGF expression is down-regulated during head and neck tumorigenesis. However, further studies are required to better understand the mechanism of VEGF down-regulation in head and neck tumorigenesis.

Papillary squamous cell carcinomas of the upper aerodigestive tract: a clinicopathologic and molecular study

BACKGROUND

The limited studies and the small number of published cases of papillary squamous cell carcinoma have precluded accurate assessment of the biologic characteristics of this lesion.

METHODS

Thirty-eight of the carcinomas were studied. In-situ hybridization and polymerase chain reaction were performed to detect human papilloma virus (HPV) and p53 expression.

RESULTS

HPV was found in 4 of 14 assessable carcinomas by in-situ hybridization and in 5 of 14 by polymerase chain reaction. The most frequently identified HPVs were HPVs in 6/11 and 16/18 patients. In general, a reciprocal relationship was found between p53 and HPV prevalence. The most lethal site for this tumor was the sinonasal tract, whereas patients with papillary squamous cell carcinomas of the larynx had the best outlook. Eleven of 25 (44%) assessable patients died of disease (mean time interval, 2 year).

CONCLUSIONS

Papillary squamous cell carcinoma of the upper aerodigestive tract is a distinct variant of squamous cell carcinoma. As such and because of its putative association with HPV, papillary squamous cell carcinoma could be an informative model for defining how viral oncogenes cooperate with other factors in genomic instability, carcinogenesis, and tumor development.

Predicting cancer development in oral leukoplakia: ten years of translational research

Our 10-year translational study of the oral premalignant lesion (OPL) model has advanced the basic understanding of carcinogenesis. Although retinoids have established activity in this model, a substantial percentage of our OPL patients progress to cancer, especially after treatment is stopped. On the basis of our 10-year OPL study, we have developed the first comprehensive tool for assessing cancer risk of OPL patients. This cancer risk assessment tool incorporates medical/demographic variables, epidemiological factors, and cellular and molecular biomarkers. Between 1988 and 1991, 70 advanced OPL patients were enrolled in a chemoprevention trial of induction with high dose isotretinoin (1.5 mg/kg/day for 3 months) followed by 9 months of maintenance treatment with either low dose isotretinoin (0.5 mg/kg/day) or beta-carotene (30 mg/d; total treatment duration, 1 year). We assessed the relationship between cancer risk factors and time to cancer development by means of exploratory data analysis, logrank test, Cox proportional hazard model, and recursive partitioning. With a median follow-up of 7 years, 22 of our 70 patients (31.4%) developed cancers in the upper aerodigestive tract following treatment. The overall cancer incidence was 5.7% per year. The most predictive factors of cancer risk are OPL histology, cancer history, and three of the five biomarkers we assessed (chromosomal polysomy, p53 protein expression, and loss of heterozygosity at chromosome 3p or 9p). In the multivariable Cox model, histology (P = 0.0003) and the combined biomarker score of chromosomal polysomy, p53, and loss of heterozygosity (P = 0.0008) are the strongest predictors for cancer development. Retinoic acid receptor beta and micronuclei were not associated with increased cancer risk. We have demonstrated a successful strategy of comprehensive cancer risk assessment in OPL patients. Combining conventional medical/demographic variables and a panel of three biomarkers can identify high risk patients in our sample. This result will need to be validated by future studies. With the identification of high risk individuals, more efficient chemoprevention trials and molecular targeting studies can be designed.

High metastatic potential in mice inheriting a targeted p53 missense mutation

To understand the relevance of p53 missense mutations in vivo, we generated a mouse containing an arg-to-his substitution at p53 amino acid 172, which corresponds to the R175H hot-spot mutation in human tumors by homologous recombination. Inadvertently, this mouse contains the additional deletion of a G nucleotide at a splice junction that attenuates levels of mutant p53 to near wild-type levels. Mice heterozygous for the mutant allele differed from p53(+/-) mice in tumor spectrum, with a significant increase in the number of carcinomas and a slight decrease in the number of lymphomas. More importantly, the osteosarcomas and carcinomas that developed in these mutant mice frequently metastasized (69% and 40%, respectively). In contrast, metastasis is rare in osteosarcomas of p53(+/-) mice. Loss of heterozygosity studies of tumors indicated loss of heterozygosity in only 1 of 11 tumors. These data indicate clear differences between a p53 missense mutation and a null allele in tumorigenesis in vivo and suggest that the p53R172HDeltag mutant represents a gain-of-function allele.