Head and neck cancer

Potential biomarkers in predicting progression of epithelial hyperplastic lesions of the larynx

Factors contributing to malignant transformation of laryngeal pre-neoplastic lesions remain largely unknown. Potential etiologic factors may be related to a genetically controlled sensitivity to environmental carcinogens. In this study, we investigated bleomycin-induced chromosome fragility in 15 patients with laryngeal keratoses who experienced a malignant transformation of pre-neoplastic lesions during follow-up, as compared with chromosome fragility in 15 historical controls with no progression of laryngeal keratoses during a 10-year follow-up, in a match-paired analysis. Chromosomal analysis demonstrated a higher sensitivity to clastogens in patients with malignant progression of laryngeal pre-neoplastic lesions than that of control patients with no evolution of their original laryngeal keratoses (p < 0.01). Furthermore, in the attempt to identify possible prognostic markers we studied proliferative activity (MIB-1 expression) and p53 gene aberration in biopsy samples from non-invasive and invasive laryngeal lesions in both groups. p53 immunostaining was observed in 10/15 (66.7%) of pre-neoplastic lesions and in 11/15 (73.3%) of metachronous laryngeal cancers. No differences in terms of p53 expression were noted between transformed and not-transformed lesions. Mutations at p53 gene were observed in 3/15 (20%) of pre-invasive biopsies and in 4/5 (80%) of the laryngeal cancers analyzed. Our data suggest that p53 alteration is an early event in the genesis of a subset of laryngeal carcinomas and that there is no conclusive data about the possible clonal development of metachronous laryngeal carcinoma from a p53 mutated pre-invasive disease in the same patient. MIB-1 expression was found to progressively increase with degree of epithelial hyperplasia and dysplasia in both transformed (p = 0.007) and not-transformed (p < 0.1) lesions. Surprisingly, pre-invasive lesions with tumor evolution showed a lower proliferative activity when compared with laryngeal lesions without malignant transformation (p = 0.013). These data suggests that subjects with pre-neoplastic laryngeal lesion showing an increased susceptibility to carcinogens and with less proliferative disease could be at a higher risk for development of laryngeal carcinoma.

Increased mutagen-induced chromosome damage in patients with transformed laryngeal pre-cancerosis

Factors that contribute to malignant transformation of laryngeal pre-neoplastic lesions remain largely unknown. Potential etiological factors may be related to a genetically controlled sensitivity to environmental carcinogens. In this study, we investigated bleomycin-induced chromosome damage in 15 patients who experienced a malignant transformation of preneoplastic laryngeal lesions during follow-up, as compared with chromosome fragility in 30 historical controls with no progression of keratoses during a 10-year follow-up, in a match-paired analysis. Chromosomal analysis demonstrated higher sensitivity to clastogens in patients with malignant progression of laryngeal pre-neoplastic lesions than that of control patients with no evolution of their original laryngeal keratoses (p = 0.003). Furthermore, among the study patients, chromosome sensitivity was most apparent in non-tobacco users with malignant transformation of laryngeal disease. Our data suggest that subjects with pre-neoplastic laryngeal lesion showing increased susceptibility to carcinogens could be at higher risk for development of laryngeal carcinoma.

The erbB oncogenes as prognostic markers in oral squamous cell carcinomas

BACKGROUND

In clinical practice it became clear that conventional prognostic parameters of oral squamous cell carcinomas (OSCC) are of limited value for the prediction of a disease-free survival. The overexpression of erbB oncogenes is of importance for the clinical course of a variety of solid tumors. After discovering amplifications of erbB oncogenes even in OSCC, it was the aim of the present study to clarify the potential of oncogenes as additional prognostic markers.

MATERIALS AND METHODS

The amplification of the erbB oncogenes in tumorous tissue of 85 OSCC patients was determined using the double-differential polymerase chain reaction. Histologically healthy mucosa in these patients was also studied. In univariate analysis the amplification of erbB oncogenes with clinical and histopathological prognostic parameters was compared.

RESULTS

No significant correlation between common prognostic parameters and erbB-2 amplification was found. Patients whose OSCC tissue showed an average gene copy number for erbB-2 of greater than 1.2, for erbB-3 below 0.11, and a ratio of erbB-1 and erbB-2 below 0.31 had a statistically significant decrease in disease-free survival. Even in histologically healthy oral mucosa from tumor patients an amplification of erbB oncogenes was found.

CONCLUSIONS

ErbB oncogene amplifications in oral squamous cell carcinomas play a significant role as a prognostic factor and seem to be effective in predicting decrease in disease-free survival. Genetic abnormalities in tumor-surrounding tissue support the field cancerization hypothesis.

Does induction chemotherapy have a role in the management of nasopharyngeal carcinoma? Results of treatment in the era of computerized tomography

PURPOSE

To assess the outcomes of patients with nasopharyngeal carcinoma (NPC) whose treatment was determined by computerized tomography (CT) and/or magnetic resonance imaging staging and to analyze the impact of induction chemotherapy and accelerated fractionated radiotherapy.

METHODS AND MATERIALS

The analysis is based on 122 of 143 previously untreated patients with NPC treated with radiation therapy at The University of Texas M. D. Anderson Cancer Center between 1983 and 1992. Excluded were 4 patients treated with palliative intent, 4 children, 12 patients not staged with CT, and 1 patient who died of a cerebrovascular accident prior to completion of treatment. The stage distribution was as follows: AJCC Stage I-2, Stage II-7, Stage III-12, Stage IV-101; Tl-15, T2-33, T3-22, T4-52; N0-32, N1-10, N2-47, N3-32, Nx-1. Fifty-nine (48%) patients had squamous cell carcinoma; 63 (52%) had lymphoepitheliomas, undifferentiated NPC or poorly differentiated carcinoma, NOS (UNPC). Sixty-seven patients (65 with Stage IV disease) received induction chemotherapy. Fifty-eight patients (24 of whom had induction chemotherapy) were treated with the concomitant boost fractionation schedule. The median follow-up for surviving patients was 57 months.

RESULTS

The overall actuarial 2- and 5-year survival rates were 78 and 68%, respectively. Forty-nine patients (40%) had disease recurrence. Thirty-three (27%) had local regional failures; 19 at the primary site only, 8 in the neck and 6 in both. Local failure occurred in 31% of patients staged T4 compared to 13% of T1-T3 (p = 0.007). Sixteen patients failed at distant sites alone. Among Stage IV patients the 5-year actuarial rates for patients who did and did not receive induction chemotherapy were as follows: overall survival: 68 vs. 56% (p = 0.02), freedom from relapse: 64 vs. 37% (p = 0.01), and local control: 86 vs. 56% (p = 0.009). The actuarial 5-year distant failure rate in patients with UNPC who were treated with induction chemotherapy and controlled in the primary and neck was 13%. In patients who did not receive chemotherapy, the actuarial 5-year local control rates for patients treated with concomitant boost or conventional fractionation were 66 and 67%, respectively.

CONCLUSIONS

While not providing conclusive evidence, this single institution experience suggests that neoadjuvant chemotherapy for Stage IV NPC patients improves both survival and disease control. Recurrence within the irradiated volume was the most prevalent mode of failure and future studies will evaluate regimens to enhance local regional control.

Differential effects of retinoic acid and N-(4-hydroxyphenyl)retinamide on head and neck squamous cell carcinoma cells

Both retinoic acid (RA) and the synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) have shown efficacy in head and neck cancer chemoprevention trials. To compare their activity and mechanism of action, the 1483 oral head and neck squamous cell carcinoma (HNSCC) cell line was grown in organotypic culture, an in vitro system that allows cellular stratification and simulates carcinoma in situ, and was exposed to 10 micromol/L of either RA or 4HPR. Extensive apoptosis, as evidenced by in situ deoxyribonucleic acid end-labeling, occurred in 4HPR-treated cultures after 9 days, with >80% cell loss (P< .001). In contrast, the growth of cultures treated with RA was inhibited by only 32%, with no evidence of apoptosis. Because 4HPR has low systemic toxicity and is a potent inducer of apoptosis in HNSCC cells, its role in chemoprevention of head and neck cancers, including cancers that are resistant to RA-induction therapy, warrants further investigation.

Autopsy findings in patients with head and neck squamous cell cancer and their therapeutic relevance

A series of 63 autopsied patients with a history of head and neck squamous cell cancer (HNSCC) is reported with emphasis on the importance of locoregional disease (LRD) versus distant metastasis (DM) in the terminal course of the disease. There were 49 males and 14 females; mean age 64.9 years (range 35-94 years). Locoregional disease was present in 39 patients (62%), in 25 (40%) without tumour at other body sites outside the head and neck region. Distant metastasis was observed in 15 patients (24%); in 12 (19%), it occurred with concomitant LRD. Second primary tumours (SPT) were observed in 20 patients (32%). They occurred in the head and neck region (n = 7; 11%), the lung (n = 9; 14%) and at miscellaneous other sites (n = 4; 6%). Of the 13 patients with SPT outside the head and neck region, 2 had concomitant LRD. 11 patients (17%) died due to other causes, no tumour being found at autopsy. These figures indicate that still a major part of HNSCC patients die with LRD as the single tumour manifestation, which means that improvement of local tumour control will result in a significant therapeutic gain.

Re-irradiation with concomitant chemotherapy of unresectable recurrent head and neck cancer: a potentially curable disease

PURPOSE

The purpose of this study was to review the outcome following concomitant chemoradiation therapy in previously irradiated patients with locally or regionally recurrent or persistent head and neck cancer considered unresectable for cure.

METHODS AND MATERIALS

We identified 45 patients treated between 1986 and 1993 with unresectable locally or regionally recurrent disease who were treated on one of four concomitant chemoradiotherapy phase I/II studies at the University of Chicago. All patients received hydroxyurea (HU), 5-fluorouracil (5-FU) and concomitant radiation therapy on an alternate week schedule (FHX). Cisplatin was added to FHX in three of the studies.

RESULTS

The overall survival, progression-free survival, and local/regional control at 5 years was 14.6%, 13.5% and 20%, respectively, in a cohort of patients whose disease is almost universally fatal. Fatal treatment related complications were observed in 5 (11%) of patients. Two of these complications were related to radiation therapy. Stepwise Cox regression analysis revealed that dose and protocol were significantly correlated with survival, progression-free survival and local/regional control. A direct correlation was observed with radiation dose and an inverse correlation was observed with the initial FHX dose escalation study. The 2-year survival was 35% in patients receiving over 58 Gy compared to 8% for those receiving less than 58 Gy.

CONCLUSIONS

Our results show that aggressive re-irradiation with concomitant chemotherapy of recurrent head and neck cancer results in the cure of some patients with acceptable toxicity if tumoricidal doses are applied. These results are in contrast to historical series of chemotherapy alone which results in limited palliation of brief duration and almost no chance of cure. Thus, re-irradiation with concomitant chemotherapy should be further investigated as an alternative to chemotherapy alone in multi-center or cooperative group randomized trials.

Cell kinetics and tumor regression during radiotherapy in head and neck squamous-cell carcinomas

Head and neck squamous-cell carcinoma (HN-SCC) patient management is mainly based on TNM classification and needs be improved by considering other potentially useful prognostic factors. We examined the pre-radiotherapy tumor potential doubling time (Tpot) evaluated after in vivo infusion of bromodeoxyuridine and flow-cytometric analysis and the early clinical tumor regression after 40 Gy (40 Gy-TR). Tpot values and clinical 40 Gy-TR classes (minor and major) were available for 82 HN-SCC patients. Radiation therapy completion was done either with 1 dose per day (conventional regimen) or 2 doses per day (accelerated regimen). Local control was also available for follow-up times above 4 years. We found that major 40 Gy-TR was strongly correlated with fast tumor growth, characterized by Tpot values below 5 days, and that patients with major 40 Gy-TR showed better local control than those with minor 40 Gy-TR, independently from the radiotherapy regimen type. We also found that treatment completion with accelerated radiotherapy gave better local control for patients with major 40 Gy-TR and fast tumor growth than conventional radiotherapy. Multivariate analysis, performed on all patients, assigned an independent prognostic value to Tpot, tumor classification and 40 Gy-TR.

Molecular biology of human oral cancer

The application of molecular biological tools to the study of cancer has significantly advanced the field of human cancer research. Such study has demonstrated the involvement of two classes of highly conserved cellular genes in the malignant transformation process: oncogenes and tumor suppressor genes. Despite these advances in the molecular biology of human cancers, our understanding of human oral cancer lags behind that of cancer of other body sites. This review attempts to assess the current status of the molecular biology of human oral cancer.

Photodynamic therapy using 5-aminolevulinic acid for premalignant and malignant lesions of the oral cavity

BACKGROUND

Premalignant changes in the mouth, which are often widespread, are frequently excised or vaporized, whereas cancers are treated by excision or radiotherapy, both of which have cumulative morbidity. Photodynamic therapy (PDT) is another option that produces local tissue necrosis with light after prior administration of a photosensitizing agent. This heals with remarkably little scarring and no cumulative toxicity. This article describes the use of PDT with the photosensitizing agent 5-aminolevulinic acid (ALA) for premalignant and malignant lesions of the mouth.

METHODS

Eighteen patients with histologically proven premalignant and malignant lesions of the mouth were sensitized with 60 mg/kg ALA by mouth and treated with laser light at 628 nanometers (100 or 200 Joules/cm2). The results were assessed macroscopically and microscopically. Biopsies were taken immediately prior to PDT for fluorescence studies, a few days after PDT to assess the depth of necrosis, when healing was complete, and up to 88 weeks later.

RESULTS

The depth of necrosis varied from 0.1 to 1.3 mm, but complete epithelial necrosis was present in all cases. All 12 patients with dysplasia showed improvement (repeat biopsy was normal or less dysplastic) and the treated areas healed without scarring. Some benefit was observed in five of six patients with squamous cell carcinoma, but only two became tumor free (one with persistent mild dysplasia). No patient had cutaneous photosensitivity for longer than 2 days.

CONCLUSIONS

PDT using ALA for dysplasia of the mouth produces consistent epithelial necrosis with excellent healing and is a simple and effective way to manage these patients. Results in invasive cancers are less satisfactory, mainly because the PDT effect is too superficial with current treatment regimens using ALA as the photosensitizing agent.

Familial risks of squamous cell carcinoma of the head and neck: retrospective case-control study

OBJECTIVE

To determine the contribution of inheritance to the incidence of squamous cell carcinoma of the head and neck.

DESIGN

Historical cohort study. First degree relatives of cases with squamous cell carcinoma of the head and neck made up the exposed cohort and first degree relatives of spouses of cases made up the comparison unexposed cohort.

SETTING

Ear, nose, and throat clinic in a large metropolitan teaching hospital.

SUBJECTS

1429 first degree relatives of 242 index cases of squamous cell carcinoma of the head and neck; as controls, 934 first degree relatives of the spouses of 156 index cases.

MAIN OUTCOME MEASURES

Relative risk of developing squamous cell carcinoma in first degree relatives of cases compared with risk in first degree relatives of spouses.

RESULTS

The adjusted relative risk for developing head and neck cancer if the index case had squamous cell carcinoma of the head and neck was 3.79 (95% confidence interval 1.11 to 13.0). There were no significantly increased risks associated with a family history of cancer at other sites. The adjusted relative risk for squamous cell carcinoma of the head and neck was 7.89 (1.50 to 41.6) in first degree relatives of patients with multiple primary head and neck tumours.

CONCLUSIONS

These data suggest that genetic factors are important in the aetiology of head and neck cancer, in particular for patients with multiple primary cancers. Given the prolonged exposure of these subjects to carcinogens, these genetic factors may have a role in modifying carcinogen activity or in host resistance to carcinogens. Inherited factors may be important in persons with environmentally induced cancers.

Microsatellite alterations in serum DNA of head and neck cancer patients

Microsatellite DNA alterations are an integral part of neoplastic progression and are valuable as clonal markers for the detection of human cancers. Moreover, recent evidence suggests that senescent tumor cells may release DNA into the circulation, which is subsequently carried by and therefore enriched in the serum and plasma. We tested 21 patients with primary head and neck squamous cell carcinoma (HNSCC) by polymerase chain reaction (PCR)-based microsatellite analysis of DNA from lymphocytes and paired serum samples. Patients were scored for alterations as defined by the presence of new alleles (shifts) or loss of heterozygosity (LOH) in serum at each of 12 markers and then compared with primary tumor DNA. Six out of 21 patients (29%) were found to have one or more microsatellite alterations in serum precisely matching those in the primary tumors. All six patients had advanced disease (stage III or IV); five of these patients had nodal metastases, three later developed distant metastases, and four died of disease. Microsatellite analysis of serum represents a novel method for the detection of circulating tumor cell DNA. If these results are confirmed in larger studies, microsatellite markers may be useful in assessing tumor burden in cancer patients.

Enhanced acute toxicity in oropharynx carcinoma treated with radiotherapy and concomitant cisplatin, 5-fluorouracil and mitomycin C

The aim of this study was to establish the feasibility of giving concomitant radiotherapy and 3 cycles of chemotherapy with cisplatin (CDDP), 5-fluorouracil (5-FU) and mitomycin C (MMC) in locally advanced inoperable oropharyngeal cancer. From March 1990 to September 1993, 27 male patients (mean age 55 years) were included in this study. 3 patients (11%) were T2N0, 19 (70%) T3 (T3N0: n = 9, T3N1: n = 1, T3N2: n = 5, T3N3: n = 4), and 5 (19%) T4 (T4N0: n = 1, T4N1: n = 1, T4N2: n = 2, T4N3: n = 1). All patients received conventional radiotherapy delivering 70 Gy in 35 fractions and 52 days, and three cycles of chemotherapy starting on day 1, 21 and 42 with CDDP 20 mg/m2 and 5-FU 400 mg/m2 day 1 to day 4, and MMC 10 mg/m2 day 1. With a mean follow-up of 34 months (17-59), 10 patients (37%) were alive and free of disease. Among the 17 other patients, 8 died of cancer. Crude locoregional control rate was 78%, and probability of local control at 1 and 2 years was 85 and 80%, respectively. One- and 2-year survival rates were 48 and 31%, respectively, for both overall and disease-free survival. Grade 3 or 4 mucositis occurred in 22 patients (81%); enteral feeding was necessary for 63%; mean weight loss was 5.7 kg. Grade > 2 thrombocytopenia occurred in 11 patients (41%), grade > 2 neutropenia in 8 patients (29%), grade > 2 anaemia in 4 patients (15%). Febrile neutropenia or aplasia occurred in 5 patients (19%). 2 patients (7%) died during treatment of haematological or infectious complications related to the treatment. Another patient died 1 month after treatment with grade 4 thrombocytopenia and septicaemia. In conclusion, a high complete response rate has been achieved with this concomitant chemo- and radiotherapy, but with severe digestive and haematological toxicity. Addition of MMC to 5-FU and CDDP might have been responsible for this increased toxicity. This therapeutic combination is therefore not routinely feasible.

A phase II study of ifosfamide in recurrent squamous cell carcinoma of the head and neck

Chemotherapy has not significantly altered the overall survival of patients with recurrent squamous cell carcinoma of the head and neck; therefore, the development of new agents is essential. The purpose of the current phase II study was to define the efficacy of ifosfamide in the treatment of recurrent squamous cell carcinoma of the head and neck. All patients were required to have squamous cell carcinoma of the head and neck that had recurred following surgery or radiotherapy or both. Patients may have received prior chemotherapy. Patients were initially treated with ifosfamide 2 g/m2/day for 4 days (dose level 0). Dose level-1 was 2 g/m2/day for 3 days, and dose level-2 was 2 g/m2/day for 2 days. All patients received mesna 400 mg/m2/day prior to and 1,200 mg/m2/day as a continuous infusion after ifosfamide. Thirty-eight patients were enrolled in the study. Five patients were inevaluable for toxicity or response. Overall, the regimen was well tolerated, with grade 4 granulocytopenia the only significant toxicity occurring in 16 patients. Overall, eight of 31 evaluable patients (25.8%) had a major response. Only one of the 10 patients (10%) with prior chemotherapy responded, but seven of the 21 patients (33.3%) with no prior chemotherapy had major responses. Ifosfamide is an active agent in recurrent squamous cell carcinoma of the head and neck. Further studies of ifosfamide in combination with other agents, particularly as induction therapy in patients with locally advanced disease, are warranted.

Intensive care unit stay is prolonged in chronic alcoholic men following tumor resection of the upper digestive tract

BACKGROUND

The prevalence of chronic alcohol misuse in patients with oral, pharyngeal, laryngeal or esophageal carcinomas exceeds 60%. No data is available, to our knowledge, on the morbidity and mortality of chronic alcoholics in surgical intensive care units (ICU) following tumor resection. We investigated whether the subsequent ICU stay in chronic alcoholics following tumor resection was prolonged and whether the incidence of pneumonia and sepsis was increased.

METHODS

213 patients with carcinomas of the upper digestive tract were evaluated regarding their drinking habits. Chronic alcoholics met either the DSM-III-R criteria for alcohol abuse or dependence. Conventional laboratory markers and serum carbohydrate-deficient transferrin were determined preoperatively. Major intercurrent complications during ICU stay such as an alcohol withdrawal syndrome, pneumonia and sepsis as well as the frequency of death were documented.

RESULTS

Patients did not differ significantly between groups regarding age or APACHE score on admission to the ICU.121 patients were diagnosed as being chronic alcoholics, 39 as being social drinkers and 61 as being non-alcoholics. In chronic alcoholics the frequency of death was significantly increased. Due to the increased incidence of pneumonia and sepsis the ICU stay was significantly prolonged in chronic alcoholics by approximately 8 days.

CONCLUSIONS

The increased mortality and morbidity rate demonstrates that chronic alcoholics undergoing major tumor surgery have to be considered as high-risk patients during their postoperative ICU stay. Further studies are required with respect to the immuno-competence of chronic alcoholics and the prevention of alcohol withdrawal syndrome, pneumonia and sepsis in these patients.

Prevalence of mucosotropic human papillomaviruses in squamous-cell carcinoma of the head and neck

The prevalence of mucosotropic human papillomavirus (HPV) DNA in 63 squamous-cell carcinomas (SCC) from different anatomic sites in the head and neck was determined by general primer-mediated polymerase chain reaction (GP-PCR). HPV DNA was detected in 20.6% of SCC. Additional type-specific PCR for HPV 6, 11, 16, 18, 31 and 33 demonstrated the presence of HPV 16 alone in these carcinomas. HPV 16 was also detected in normal epithelium from the resection margins of the majority of HPV-positive SCC. HPV status did not correlate with tumour site, whether primary or recurrent, TNM stage, metastases, degree of differentiation, smoking or alcohol history, fate or survival.

Intensive short cause chemotherapy followed by radiotherapy of locally advanced nasopharyngeal carcinoma

BACKGROUND

We designed a protocol with the goal of improving the disease free and overall survival of patients with previously untreated Stage IV nasopharyngeal carcinoma (NP(C)). The regimen consisted of intensive induction chemotherapy followed shortly thereafter by radiation therapy.

METHODS

Between March 1986 and March 1992, 27 patients with T3-4, N2-3, M0 squamous cell carcinoma of the nasopharynx were treated with 2 cycles of chemotherapy, using cisplatin, 100 mg/m2 intravenously, on Day 1, and 5-fluorouracil (5-FU), 1000 mg/m2 per day continuous infusion, on Days 2-5. The second cycle was given on Day 16 and was followed by radiotherapy (RT), 70 Gray, given on Day 31.

RESULTS

The objective response rate to chemotherapy was 93%, with a 37% complete response (CR) rate and a 56% partial response (PR) rate. The overall CR rate after RT was 85%. With a median follow-up of 60 months, the overall actuarial survival rate was 66%. Patients who had a CR after chemotherapy had a superior survival probability (100%). Toxicity was tolerable, without lethal complications.

CONCLUSIONS

This study demonstrates that cisplatin/5-FU chemotherapy given in an intensive schedule and followed shortly thereafter by radical RT can improve the CR rate and survival of patients with locally advanced NPC, with tolerable toxicity.

Neurotoxicity in a phase I trial of continuous infusion cisplatin with hyperfractionated radiotherapy for locally advanced head and neck cancer

BACKGROUND

Both twice daily fractionated radiotherapy and concurrent cisplatin with once-daily radiotherapy have been shown to improve local disease control in patients with head and neck cancer. The objective of this phase I trial was to determine the maximum tolerated dose of cisplatin which could be given as a continuous infusion concurrent with twice-daily radiotherapy to patients with locally advanced head and neck cancer.

METHODS

Patients were treated with radiotherapy at doses of 110 cGy twice daily for 5 days per week to a total dose of 7040-7590 cGy. Concurrent with radiotherapy, patients received continuous-infusion cisplatin for 5 days per week. Groups of 3-6 patients were treated with doses of 1-3 mg/m2/day.

RESULTS

Central nervous system toxicity became dose-limiting. At 1 mg/m2, 2 mg/m2, and 3 mg/m2 confusion was observed and one patient had a seizure. At 3 mg/m2, another patient suffered severe sensory and motor neuropathy. Despite bulky tumors, 12 of the 14 patients had an objective response and 3 achieved a complete response.

CONCLUSION

the combination of twice-daily fractionated radiotherapy and concurrent cisplatin by continuous infusion is severely toxic and achieves results similar to less toxic programs. It is not recommended for further investigation or therapy.

Fully automated determination of selective retinoic acid receptor ligands in mouse plasma and tissue by reversed-phase liquid chromatography coupled on-line with solid-phase extraction

A fully automated reversed-phase HPLC method was developed for the quantitative assay of three retinoids (Am-580, CD-2019 and CD-437) which selectively activate the retinoic acid receptors RAR alpha, RAR beta and RAR gamma, respectively. Mouse plasma, embryo and maternal tissues were prepared for injection by on-line solid-phase extraction (SPE) and valve-switching techniques. Following automatic injection, the sample was loaded on preconditioned disposable cartridges, cleaned-up and then transferred onto the analytical column to be eluted in the backflush mode, separated by gradient elution and detected by UV, while a new cartridge was concomitantly conditioned. The overall recovery was quantitative allowing for external standardization. The calibration curves were linear in all biological samples tested so far, with a correlation coefficient (r) >0.99. The intra-day precision was < or = 7.8% (n = 5-6) and the inter-day variability was < or = 9.4% (n = 3). The lower limit of detection was 2.5 ng/ml or ng/g for CD-2019 and CD-437, and 5 ng/ml for Am-580 with a S/N ratio of 5 using a sample weight of 25 microliters or mg. The method is now in routine use in our laboratory for the assessment of the pharmacokinetic profiles of these retinoids. The small sample size required, the simple sample preparation and the rapid analysis with high degree of automation make this method convenient for microanalysis of biological samples both in animal and human studies.

Cisplatin, 5-fluorouracil, and high-dose folinic acid in patients with advanced unresectable head and neck cancer

For patients with advanced, unresectable head and neck (HN) cancer, surgery and/or radiotherapy are the standard treatments but have poor results. A phase II trial of a continuous infusion of cisplatin, 5-FU, and high dose folinic acid (PFL) as induction chemotherapy in patients with previously untreated, locally advanced HN cancer was performed in an attempt to confirm the encouraging results reported by Dana Farber investigators using an identical regimen. Forty-five consecutive patients with unresectable HN cancer were treated every 28 days with a continuous infusion of cisplatin 25 mg/m(2)/day (days 1-5), 5-FU 800 mg/m(2)/day (days 2-6), and folinic acid 500 mg/m(2)/day (days 1-6). After three courses of chemotherapy, patients were treated with surgery and/or radiotherapy. Objective responses were observed in 26 of 38(69%) evaluable patients with 14(37%) clinical complete responses. Grade III-IV toxicity was important and consisted mainly of mucositis and neutropenia that were found in 47 and 18%, respectively , of patients after the first course. There was one toxic death. PFL is an active, toxic induction regimen for far-advanced HN cancer, yielding a response rate in the range of the widely used cisplatin and 5-FU (PF) schedule; a comparative trial is warranted before concluding that PFL is superior to the latter combination.

Exfoliative cytology in clinical oral pathology

Exfoliative cytology is a rapid, non-invasive procedure for assessing dysplastic change within the oral epithelium. The indications for oral exfoliative cytology are reviewed and a technique for cell collection and smear examination is presented. The value of exfoliative cytology in oral cancer screening programmes as a public health measure is discussed.

Clinical studies in head and neck cancer chemoprevention

Secondary neoplasms represent a major threat for patients with head and neck cancer. The prevention of secondary neoplasms has been a major goal of head and neck cancer chemoprevention efforts. In order to help develop effective strategies, reversal of oral premalignancy has been used as a model for chemoprevention. There is now sufficient data to show the chemopreventive effect in premalignant lesions of some natural compounds and their derivatives. Retinoids are the most studied chemopreventive agents for the treatment of oral leukoplakia. Other compounds with chemopreventive activity are carotenoids, Vitamin E derivatives and Selenium. There are two large prospective, randomized, chemoprevention clinical trials, one in Europe and the other in North America, using prevention of secondary malignancy as the primary study end-point. Until these trials are completed, the use of chemoprevention in head and neck cancer should be limited to clinical trials.

Laser photochemotherapy with anthracyclines on cultured human squamous carcinoma cells

A new treatment for cancer has been tested in vitro using light-sensitive anthracyclines followed by laser photoactivation, as described by several investigators. We previously reported 10-fold enhanced laser killing after 2 hours of incubation with daunomycin by cultured human carcinoma cells. This short-term uptake leads to drug localization in cytoplasmic and membrane sites prior to nuclear accumulation and topoisomerase inhibition. In the present study, daunomycin was incubated for 2 or 24 hours with P3 squamous carcinoma cells to directly compare cytoplasmic vs. nuclear drug targeting before and after KTP-532 laser activation. Monolayer cultures of the P3 cells sensitized with daunomycin for 2 hours, then chilled (4 degree C), and exposed to the KTP laser (532 nm, 94.2 J/cm2) had a 2- to 10-fold increased therapeutic response compared with drug or laser alone when measured by MTT tetrazolium assays. After 24 hours of incubation with daunomycin, the chemotherapeutic response of P3 tumor cells was amplified 2-fold by laser exposure. The results suggest that daunomycin and laser treatment can be combined for improved therapy of human cancer.

Molecular and cellular biomarkers for field cancerization and multistep process in head and neck tumorigenesis

One way to explain the development of head and neck cancer is through the theories of field cancerization, i.e., the exposure of an entire field of tissue to repeated carcinogenic insult, and multistep process, i.e., development of multiple cancers in a predisposed filed through a series of recognizable stages. Recent molecular genetic studies of histologically normal and premalignant epithelia of high-risk subjects and studies of malignant tumors in aerodigestive tract epithelia have identified a continuum of accumulated specific genetic alterations that possibly occur during the clonal evolution of tumors, namely, during the multistep process. Second primary or multiple primary tumors arise in the same fields as independent clones, with similar but unique molecular genetic and/or cellular alterations. Consequently, the assessment of these genetic and phenotypic alterations has been integrated into clinical chemoprevention trials in an effort to identify biomarkers that are also risk predictors and intermediate end points. This review covers candidate biomarkers of the processes of field cancerization and multistep tumor development in aerodigestive tract epithelia, including general and specific genetic markers, proliferation markers, and squamous differentiation markers.

A phase I investigation of the sequential use of methotrexate and paclitaxel with and without G-CSF for the treatment of solid tumors

BACKGROUND

Paclitaxel is a novel agent with significant activity in several solid tumors. Preclinical data suggested that methotrexate prior to paclitaxel would be synergistic. To determine the qualitative and quantitative toxicity of this regimen we performed a phase I study in patients with solid tumors.

PATIENTS AND METHODS

Patients with solid tumors previously treated with no more than two prior chemotherapy regimens were given methotrexate intravenously on day 1, followed by paclitaxel, as a 24-hour infusion on day 2. The starting dose (level '0') was 40 mg/m2 for methotrexate and 135 mg/m2 for paclitaxel.

RESULTS

After achieving a maximum tolerated dose, additional patients were enrolled with the addition of G-CSF 5 mu g/kg/d on days 4-13. At the starting dose level, dose-limiting toxicity consisting of neutropenic fever occurred in 3 of 4 patients. At dose level -1, methotrexate 30 mg/m2 and paclitaxel 110 mg/m2, neutropenic fever occurred in 7 of 10 patients during the first course. At dose level -2, methotrexate 23 mg/m2 and paclitaxel 85 mg/m2, neutropenic fever occurred in 1 of 7 patients. To abrogate the neutropenia we explored the same combination with the addition of G-CSF. Neutropenic fever remained the only dose-limiting toxicity. At dose level '0' with G-CSF, 1 of 7 patients developed dose-limiting toxicity. At dose level 1 plus G-CSF, methotrexate 40 mg/m2 and paclitaxel 170 mg/m2, dose-limiting neutropenic fever occurred in 4 of 6 patients. Partial responses occurred in 4 of 41 patients entered on this study. Pharmacokinetic data suggested that methotrexate did not increase paclitaxel levels.

CONCLUSION

The combination of methotrexate and paclitaxel is feasible, but neutropenic fever, even with the addition of G-CSF prevents further escalations of paclitaxel beyond 135 mg/m2 following methotrexate.

Longitudinal assessment of quality of life in laryngeal cancer patients

BACKGROUND

Although quality of life (QL) and performance status are important outcomes in head and neck (HN) cancer, there is little systematic inclusion of these parameters in treatment trials.

METHODS

Rate and recovery of function were evaluated over a 6-month period in 21 laryngeal cancer patients, 7 in each of 3 treatment groups: total laryngectomy (group 1), hemilaryngectomy (group 2), and radiotherapy only (group 3). Assessment included Performance Status Scale for Head and Neck Cancer Patients (PSS-HN: Diet, Speech, and Eating in Public subscales) and the FACT-HN, a multidimensional QL measure.

RESULTS

Groups differed in patterns of performance recovery over time in expected directions. Group 1 recovered most slowly, without achieving normal functioning by 6 months; most of group 2 returned to normal functioning by 3 months; group 3 showed little overall dysfunction. There was no difference in overall QL between groups or over time. Performance status was significantly correlated with the FACT head and neck subscale and somewhat with the Physical subscale. In contrast, ability to eat and/or speak was not associated with overall QL nor with any other specific QL dimension (eg, emotional or social well-being).

CONCLUSIONS

Results support the sensitivity and applicability of two site-specific performance/QL measures: PSS-HN and FACT-HN. Findings also emphasize the need to employ multidimensional tools to adequately evaluate the nonmedical outcomes in head and neck patients.

Chemotherapy of squamous cell carcinoma of head and neck: the future is now

In 1996, there is an established role for chemotherapy in head and neck cancer. Patients with recurrent disease will be offered combination chemotherapy. In this setting, investigations of new drugs or combinations and the pursuit of concomitant chemo-reirradiation are of interest. In patients with locoregionally advanced disease, induction chemotherapy can be used with the goal of larynx preservation. In addition, a role for chemotherapy in nasopharyngeal cancer appears to be emerging with increased survival as therapeutic goal. The combination of cisplatin and 5-FU does not need to be tested further, however, a more definitive evaluation of a biochemically modulated PF regimen might be of interest. Furthermore, induction chemotherapy represents an ideal investigational tool in which to further evaluate the activity of several new drugs in head and neck cancer patients. Finally, concomitant chemoradiotherapy has resulted in increased survival in several randomized clinical studies. Given the poor outcome of standard radiotherapy in patients with unresectable disease, we favor the administration of concomitant chemoradiotherapy in this group of patients as a standard therapy. In our opinion, the use of radiation therapy alone in this group of patients should be restricted to patients with poor performance status or other high medical risks that render the administration of chemotherapy unadvisable. Finally, given the high incidence of second malignancies and general medical complications in cured head and neck cancer patients, studies of chemoprevention and good preventive medical care by a medical oncologist should be made available to all patients.

Head and neck cancer

This synthesis of the literature on radiotherapy for head and neck cancer is based on 424 scientific articles, including 3 meta-analyses, 38 randomized studies, 45 prospective studies, and 246 retrospective studies. These studies involve 79174 patients. The literature review shows that radiotherapy, either alone or in combination with surgery, plays an essential role in treating head and neck cancers. When tumors are localized, many tumor patients can be cured by radiotherapy alone and thereby maintain full organ function (1, 2). Current technical advancements in radiotherapy offer the potential for better local tumor control with lower morbidity (3). This, however, will require more sophisticated dose planning resources. To further improve treatment results for advanced tumors, other fractionation schedules, mainly hyperfractionation, should be introduced (5). This mainly increases the demands on staff resources for radiotherapy. The combination of radiotherapy and chemotherapy should be subjected to further controlled studies involving a sufficiently large number of patients (4, 5). Interstitial treatment (in the hands of experienced radiotherapists) yields good results for selected cancers. The method should be more generally accessible in Sweden. Intraoperative radiotherapy should be targeted for further study and development.

Family history of cancer is a risk factor for squamous cell carcinoma of the head and neck in Brazil: a case-control study

To determine the role of familial factors in head and neck cancer, we analysed data from a hospital-based case-control study of squamous cell carcinoma of the head and neck in Brazil. There were 754 cases of squamous cell carcinoma of the head and neck (SCCHN) and 1,507 age- and gender-matched hospital-based controls with non-malignant diseases. Subjects provided information on the occurrence of cancer in first-degree relatives, as well as about other risk factors, including tobacco and alcohol consumption. Relative risks (RRs) were estimated for developing mouth, pharynx and larynx cancer when cancers in relatives were observed. RRs were adjusted for age, sex, city of admission and alcohol and tobacco consumption. The RR for developing SCCHN if a first-degree relative had cancer at any site was significantly elevated at 1.97. The RR was 3.65 (95% CI: 1.97-6.76) if the relative had head and neck cancer. Significantly elevated risks for developing head and neck cancer were associated with siblings with head and neck cancer (RR = 8.57) and, to a lesser extent, with fathers with head and neck cancer (RR = 2.49). There was no significantly increased risk associated with mothers with head and neck cancer, but these tumours were rare among mothers. Our data show that familial, possibly genetic, factors are important in the aetiology of head and neck cancer.

Second primary malignancies in the head and neck cancer patient

With improvements in locoregional control, the problem of second primary malignancies is rapidly being pushed to the forefront of head and neck oncology. While the constant long-term risk for the head and neck cancer patient has been well established, efforts at prevention, early detection, and treatment have been somewhat futile. Recent advances in genetic predisposition, biomarkers, photodiagnostic imaging, and differentiation therapy may soon offer improved outcomes. The literature is reviewed and current research is presented regarding the history, epidemiology, etiology, diagnosis, and treatment of second primary malignancies.

Schedule-dependent therapeutic efficacy of the combination of gemcitabine and cisplatin in head and neck cancer xenografts

Gemcitabine and cisplatin are both drugs with proven clinical activity in various tumour types, have no overlapping toxic side-effects and are different with respect to cellular metabolism. We, therefore, performed an in vivo study to determine the efficacy of the combination of these two drugs using two human head and neck squamous cell carcinoma xenograft lines, subcutaneously growing in athymic nude mice. 100 mg/kg gemcitabine was given intraperitoneally on days 0, 3, 6 and 9 and 4 mg/kg cisplatin intravenously on days 0 and 6. In one tumour line, the combination treatment resulted in better effects than those observed when the drugs were administered individually. In the other cell line, addition of cisplatin did not increase the moderate effect of gemcitabine. Experiments with single dose injections of both drugs showed adverse effects when the interval was extended to 24 h. These data are of potential interest for clinical application, and suggest that the drugs should be administered either simultaneously or with a short time interval in which cisplatin should precede gemcitabine.

Concurrent carboplatin and radiotherapy in the treatment of squamous cell carcinoma of the head and neck, stage IV. Preliminary data of a phase II study

About two-thirds of the patients with squamous cell carcinoma of the head and neck (SCCHN) are diagnosed when the disease is in a locoregionally advanced stage. If surgery is not advisable, radiotherapy is the only treatment presently available to obtain radicality. In order to improve the therapeutic efficacy of radiotherapy (RT), chemotherapy has been associated with it with the aim of eradicating possible micrometastatic foci outside the radiotherapic fields and to enhance the cytotoxic effects of radiation. Results with concomitant chemoradiotherapy have been encouraging. We carried out a phase II study with the combination of carboplatin 300 mg/m2 every 21 days and RT at conventional doses in SCCHN stage IV (non M1). We obtained an overall response of 85.7% with an 18-month survival of 70%. The toxicity was moderate. These results encourage us to continue the accural of patients.

Differential c-myc, c-jun, c-raf and p53 expression in squamous cell carcinoma of the head and neck: implication in drug and radioresistance

The expression of oncogenes c-myc, c-jun and c-raf and tumour suppressor gene p53 was assessed by northern blot analysis of 42 tumours and p53 protein expression by immunohistochemistry on paraffin-embedded sections from 36 specimens of squamous cell carcinoma of the head and neck (SCCHN) obtained before therapy. Of the 42 tumours, 89, 100 and 100% expressed c-myc, c-jun and c-raf oncogenes, respectively. These oncogene expressions did not correlate with sex, age or clinical stage of the disease. However, an association was found between low c-myc expression (P = 0.0001) and high c-jun expression (P = 0.0001) and absence of tumoral response to neoadjuvant chemotherapy. On the other hand, c-raf overexpression was observed in patients resistant to radiation therapy (P = 0.0494). Forty-two per cent of the tumours showed p53 protein overexpression, which did not correlate with any clinical parameter. This p53 protein overexpression was associated with high p53 mRNA levels (REL) (P = 0.0223). A correlation was found between increased c-myc RNA expression and lack of p53 protein expression (P = 0.0407). In addition, a lack of p53 protein expression was indicative of tumour relapse (P = 0.05). None of these biological parameters were associated with disease-free survival (Cox-Mantel test). In conclusion, the overexpression of c-myc, c-jun and c-raf may be independently associated to tumoral response to chemotherapy or radiotherapy, or to tumour relapse, but fail to predict long-term survival.

Loss of heterozygosity at 9p and 17q in human laryngeal tumors

Recent investigations revealed that the 9p arm and 17q arm of human chromosomes harbour tumour suppressor genes (TSGs) with an important role in multistage carcinogenesis. At the 9p arm is located the p16 (MTS1) TSG and probably others with an effect on various human tumours such as acute lymphoblastic leukaemia, bladder cancer, gliomas, malignant mesotheliomas, melanomas and non-small cell lung carcinomas. In addition, the 17q arm harbours BRCA1 TSG which is responsible for approximately 80% of the familial breast/ovarian cancer cases. In order to investigate the implication of these performed a loss of heterozygosity (LOH) analysis with 10 polymorphic microsatellite markers (three at the 17q arm surrounding the BRCA1 region and seven at the 9p arm). Fourteen of the 17 (82%) tumours exhibited deletions at 9p. The highest incidence of LOH (6/13, 46%) was found for the marker D9S157 at 9p22. One sample exhibited deletion of all the informative markers tested indicating deletion of the complete 9p arm. No homozygous deletions were found. LOH at the 17q arm near the BRCA1 locus was found in 6 (35%) among 17 specimens. The results of this study indicate that allelic deletions at 9p are frequent in the development of laryngeal tumours. The highest incidence of LOH was found for the marker D9S157 which is near, but distinct from the location of p16 (MTS1) tumour suppressor gene, indicating the presence of multiple tumour suppressor genes within this chromosomal region. In addition, BRCA1 TSG is implicated in the development of laryngeal tumours.

Split hyperfractionated accelerated radiation therapy and concomitant cisplatin for locally advanced head and neck carcinomas: a preliminary report

PURPOSE

The feasibility and activity of an intensive chemoradiotherapeutic scheme for patients with locally advanced squamous cell head and neck cancers were tested in a single institution Phase II pilot study.

METHODS AND MATERIALS

Between January 1990 and February 1992, 40 patients were entered into this trial. The treatment protocol consisted of split hyperfractionated accelerated radiation therapy (SHART), 1.6 Gy per fraction given twice per day to a total dose of 64-67.2 Gy for a total of 6 weeks with a 2-week gap, and cisplatin (20 mg/sqm/Days 1 to 5, in continuous perfusion) concomitantly.

RESULTS

All of the 40 patients are evaluable for response and survival. Toxicity was significant, but tolerable. A complete tumor response to this treatment was achieved by 37 patients (92.5%). With a minimal follow-up of 22 months (median 30 months) there have been 16 local relapses and 19 patients have died, 2 without tumor. The projected 2- and 3-year overall survival rates are 64% (confidence interval (CI) 95%, 49-79%) and 47%, respectively. The 2-year local control probability has been 56% (CI 95%, 39-73%).

CONCLUSION

This treatment obtains a high rate of complete responses with increased acute toxicity but tolerable late effects. Preliminary results are encouraging for laryngeal neoplasms. A longer follow-up is needed to evaluate the impact of this treatment on patient survival.

A prospective randomized study of chemotherapy adjunctive to definitive radiotherapy in advanced nasopharyngeal carcinoma

PURPOSE

A prospective randomized trial was conducted to compare chemoradiotherapy against radiotherapy alone in the treatment of locoregionally advanced nasopharyngeal carcinoma.

METHODS AND MATERIALS

Eighty-two patients with histologically proven nasopharyngeal carcinoma who had either Ho's N3 staging or any N stage with a nodal diameter of > or = 4 cm were entered. Seventy-seven patients were evaluated for tumor response and survival. The patients were randomized to receive two cycles of cisplatin 100 mg/m2 Day 1,5-fluorouracil 1000 mg/m2 24-h infusion Days 2, 3, and 4 before radical radiotherapy, and four cycles of postradiotherapy chemotherapy (37 patients) or radiotherapy alone (40 patients). All patients received radical radiotherapy to the nasopharynx and neck. The nasopharynx and upper neck were treated to 66 Gy by conventional fractionation and the lower neck to 58 Gy. Booster radiotherapy (7.5 Gy/two fractions/week) was given to any residual nodes after standard radiotherapy.

RESULTS

The patient characteristics, including staging, were similar in both arms. The overall response rate to neoadjuvant chemotherapy was 81% (19% complete response, 62% partial response). The rates of radiotherapy for boosting parapharyngeal disease or residual lymph nodes were not significantly different in the two arms. The overall complete response rate to chemoradiotherapy was 100%, and to radiotherapy alone, 95%. Toxicities in the chemoradiotherapy arm were mainly myelosuppression, nephrotoxicity, and nausea and vomiting. The degree of mucositis was not significantly different in the two arms. There was no treatment-related death. The median follow up was 28.5 months. The 2-year overall survival was 80% in the chemoradiotherapy arm and 80.5% in the radiotherapy arm. The 2-year disease-free survival was 68% in the chemoradiotherapy arm and 72% in the radiotherapy arm, without significant difference between the two arms. The locoregional relapse rate, distant metastatic rate, and median time to relapse were also not significantly different between the two arms.

CONCLUSION

Despite promising tumor response rates from Phase II trials, this prospective randomized trial has demonstrated no benefit from adjunctive chemotherapy to radiotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma.

Interstitial laser photochemotherapy with new anthrapyrazole drugs for the treatment of xenograft tumors

Photodynamic therapy (PDT) with lasers and new dyes has gained popularity in recent years as a minimally invasive technique with high tumoricidal effects in vitro and in some cancer patients. However, because new laser dyes are not FDA approved at present, the clinical evaluation of PDT may be years away. During the past 6 years we have used laser alone for photothermal ablation in both preclinical studies and in a large number of patients with an observed 60% tumor response rate. The 40% treatment failure led us to explore the possibility of combined therapy with lasers and standard chemotherapeutic drugs. We have recently tested a promising preclinical alternative using implantation of a bare 600-microns KTP 532 laser fiberoptic in multiple tumor sites 30 min after intratumor injection of the anthrapyrazole DUP-941. As a control, this drug was injected in 3 sites of P3 human squamous cell tumor transplants in nude mice, which led to tumor stasis without regression. Similar 400-600 mm3 tumors exposed to laser illumination alone (0.8 W for 5 sec) at multiple sites resulted in tumor regrowth after 10 weeks in 80% of the animals. However, combining interstitial laser illumination with intratumor DUP-941 injections led to complete tumor regression in 85% of the mice. We propose that intratumor drug injection followed by interstitial laser fiberoptic treatment represents a potentially useful new method for tumor ablation in advanced cancer patients.

Phase II study of amonafide in the treatment of patients with advanced squamous cell carcinoma of the head and the neck. An Illinois Cancer Center study

Amonafide (nafidimide), a synthetic organic compound with an inhibitory effect on cellular replication, was used in a phase II study conducted by the Illinois Cancer Center in order to assess its efficacy and toxicity in advanced or recurrent squamous cell cancer of the head and neck. Eligible patients had received no more than one prior adjuvant or neoadjuvant chemotherapy, had normal bone marrow, renal and hepatic function, ECOG performance status of 0-2, and bidimensionally measurable disease. Eligible patients were administered amonafide at a starting dose of 300 mg/m2 for five consecutive days every 3 weeks with dose escalation or de-escalation according to established hematologic criteria in the absence of disease progression. Nineteen of 22 entered patients were evaluable for response and all patients were evaluable for toxicity. Eleven of 19 patients achieved stable disease. Median time to progression after start of treatment was 57 days, for the 18 patients for whom the date of progression is known. There were no partial or complete responses. Hematologic toxicity was dose limiting with grade 3-4 neutropenia in 50 percent of patients and 4 deaths associated with neutropenic sepsis. Non-hematologic toxicity was mild to moderate with nausea and vomiting predominating. In this study, amonafide was a myelotoxic, inactive treatment in advanced/recurrent head and neck cancer. Further use in head and neck cancer appears unwarranted.

Review article: The role of oncogenes, tumour suppressor genes and growth factors in oral squamous cell carcinoma: a case of apoptosis versus proliferation

Mutation, deactivation and disregulated expression of oncogenes and tumour-suppressor genes may be involved in the pathogenesis of oral squamous cell carcinoma (SCC). Deactivation of the p53 tumour-suppressor gene allows cell proliferation and blocks apoptosis of malignant oral keratinocytes. Mutation in the ras oncogene results in persistent mitogenic signalling. Upregulatioed c-Myc expression, in the presence of growth factors, provides an additional proliferative signal. Loss of retinoblastoma tumour-suppressor gene (Rb) function may contribute to oral keratinocyte hyperproliferation and recent evidence suggests that simultaneous deactivation of both p53 and Rb is required for tumourigenesis. Enhanced Bcl-2 and reduced Fas expression inhibit tumour cell apoptosis and may convey resistance to cytotoxic drugs and T cell-mediated cytotoxicity, respectively. Exogenous mutagens such as tobacco, alcohol and viral oncogenes may cause altered expression of oncogenes and tumour-suppressor genes in some cases of oral SCC. The impact of these mechanisms on future therapies for oral SCC is highlighted.

Impact of changes in the treatment of nasopharyngeal carcinoma: an experience of 30 years

Two hundred and twenty-eight patients with nasopharyngeal carcinoma were treated in a single institution in a 31-year period. Overall survival (OS), disease-free survival (DFS), and complete response (CR) rates were analyzed. In addition, survival and control rates from 1960 to 1975 and from 1976 to 1991 were evaluated. In the latter group, a comparative study was performed between patients treated with neoadjuvant chemotherapy (NCT) before radiotherapy (RT) (45) and patients treated with radiotherapy alone (45). OS at 5 and 10 years were 42 and 34%, and DFS rates were 35 and 30%, respectively. CR was achieved in 184 patients (81%). Tumor progression and survival were strongly associated with T-category. Use of fashioned blocks, age and T-category were the most important factors influencing survival in a multivariate analysis. In the patients treated with NCT, rates of CR and OS were not significantly different when compared with the concurrent RT alone group. Ninety-nine patients had recurrence (54%) and 58 received rescue treatment. Modern radiotherapy techniques have greatly assisted in the improvement of tumor control rates. Chemotherapy must be further evaluated and new treatments for relapsed patients are needed.

Laser photochemotherapy: a less invasive approach for treatment of cancer

The effectiveness of combining surgery with chemo- and radiation therapy in treatment of human cancer provides a useful model for further development of new multimodality approaches including laser photochemotherapy. Laser endoscopy often is a useful treatment for obstructive tumors in airways, but interstitial laser fiberoptics is becoming a more precise, minimally invasive alternative for ablation of unresectable or recurrent neoplasms. Combining intratumor chemotherapy with laser energy delivery via interstitial fiberoptics should be most effective using drugs activated by photothermal energy. A number of investigators have shown that anthracyclines and cis-platinum are likely candidates for light or heat activation in cancer cells. An advantage of anthracyclines is their dual role as antitumor drugs and as photosensitizers. Because they are effective chemotherapy agents without photoactivation, two approaches are possible to increase tumor responses. Maximum tolerated dose followed by photoillumination via laser fiberoptics can be used to obtain better tumor palliation. Improved treatment response to lower intratumor drug levels after laser activation also should reduce systemic toxicity. Preclinical studies and recent case reports from several groups suggest photochemotherapy with currently approved drugs and lasers may soon become an attractive alternative for treatment of recurrent tumors in cancer patients.

Mutations, expression and genomic instability of the H-ras proto-oncogene in squamous cell carcinomas of the head and neck

Mutation and overexpression are the main activating mechanisms for the ras family of genes in human cancer and the variable tandem repeat (VTR) located at the 3' end of H-ras has been associated with this risk. In the present study, we have analysed the relative levels of expression of H-ras mRNA in 26 samples of squamous cell carcinomas of the head and neck (SCCHN) by competitive reverse transcription-polymerase chain reaction (competitive RT-PCR) and also investigated whether there is an association between ras expression and alterations in the 3'-VTR region. In addition, we have studied the incidence of point mutations in codon 12 of H-ras, codons 12 and 13 of K-ras and codon 61 of N-ras in 120 SCCHN samples. Our results indicate that only two samples carry mutations, both of which are located in codon 12 of K-ras, but that overexpression of the H-ras proto-oncogene is a frequent event in SCCHN [54% (14/26)] and is associated with a favourable prognosis: 3 of 14 patients with H-ras overexpression have died, whereas 9 of 12 patients with low levels of H-ras expression have died. We have also undertaken an analysis of these results together with our previous investigations on microsatellite instability and loss of heterozygosity in SCCHN, but no associations were found. We therefore conclude that ras mutations are an infrequent event in the progression of the SCCHN in the Western world, whereas overexpression of the H-ras proto-oncogene is a common event.