Transoral laser microsurgery and radiotherapy for oropharyngeal squamous cell carcinoma: Equitable survival and enhanced function compared with contemporary standards of care.

INTRODUCTION: We describe the 5-year oncological and functional outcomes of transoral laser microsurgery, neck dissection (TLM + ND) and adjuvant radiotherapy (PORT) used to treat patients with oropharyngeal carcinoma. The effectiveness of external carotid artery (ECA) ligation in reducing post-operative bleeding, and fibrin glue following ND in reducing wound drainage and length of hospital stay is reported. MATERIALS AND METHODS: This retrospective case review of consecutive patients undergoing TLM between 2006 and 2017 used the Kaplan-Meier Estimator and Log-Rank Test for univariate, time-to-event analyses, and Cox-Proportionate Hazard modelling for multivariate analysis. RESULTS: 264 consecutive patients were included. Mean follow-up was 49.4 months. 219 (82.9%) patients received PORT. Five-year overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) rates were 74.9%, 73.7%, and 86.2%, respectively. Five-year locoregional control was 89.4%. 65.5% of cases were Human papillomavirus associated (HPV+), for whom OS, DFS and DSS was 85.6%, 84.7% and 92.7%, respectively, and demonstrated significantly higher OS (hazard ratio (HR) 0.28, CI 0.16-0.49, p < 0.0001), DFS (HR 0.28, CI 0.17-0.47, p < 0.0001) and DSS (HR 0.2, CI 0.09-0.44, <0.001). Post-operative oropharyngeal bleeding occurred in 23 patients (8.7%), of which 5 were major/severe, in patients without ECA ligation. Fibrin glue significantly reduced neck drain output (p < 0.001), and length of hospital stay (p < 0.001). One-year gastrostomy dependence rate was 2.3%. CONCLUSIONS: TLM + ND + PORT results in favourable 5-year survival and locoregional control rates, and low feeding tube dependency rates. ECA ligation and fibrin glue appear to reduce major post-operative haemorrhage, wound drainage and length of hospital stay.

LINE-1 ORF2p expression is nearly imperceptible in human cancers.

BACKGROUND: Long interspersed element-1 (LINE-1, L1) is the major driver of mobile DNA activity in modern humans. When expressed, LINE-1 loci produce bicistronic transcripts encoding two proteins essential for retrotransposition, ORF1p and ORF2p. Many types of human cancers are characterized by L1 promoter hypomethylation, L1 transcription, L1 ORF1p protein expression, and somatic L1 retrotransposition. ORF2p encodes the endonuclease and reverse transcriptase activities required for L1 retrotransposition. Its expression is poorly characterized in human tissues and cell lines. RESULTS: We report mass spectrometry-based tumor proteome profiling studies wherein ORF2p eludes detection. To test whether ORF2p could be detected with specific reagents, we developed and validated five rabbit monoclonal antibodies with immunoreactivity for specific epitopes on the protein. These reagents readily detect ectopic ORF2p expressed from bicistronic L1 constructs. However, endogenous ORF2p is not detected in human tumor samples or cell lines by western blot, immunoprecipitation, or immunohistochemistry despite high levels of ORF1p expression. Moreover, we report endogenous ORF1p-associated interactomes, affinity isolated from colorectal cancers, wherein we similarly fail to detect ORF2p. These samples include primary tumors harboring hundreds of somatically acquired L1 insertions. The new data are available via ProteomeXchange with identifier PXD013743. CONCLUSIONS: Although somatic retrotransposition provides unequivocal genetic evidence for the expression of ORF2p in human cancers, we are unable to directly measure its presence using several standard methods. Experimental systems have previously indicated an unequal stoichiometry between ORF1p and ORF2p, but in vivo, the expression of these two proteins may be more strikingly uncoupled. These findings are consistent with observations that ORF2p is not tolerable for cell growth.

Midbrain Gliofibroma Presenting in Adulthood following "Cure" of a Childhood Intraventricular Pilocytic Astrocytoma.

INTRODUCTION: Gliofibromas are rare biphasic tumours with a good prognosis that usually occur in childhood. Rare adult spinal cases have been treated with radiotherapy. This report describes the case of a gliofibroma occurring in a young adult 10 years after treatment for a childhood pilocytic astrocytoma. CASE: A 14-year-old female underwent complete resection of a right lateral ventricle pilocytic astrocytoma confirmed on postoperative magnetic resonance imaging (MRI). At the age of 17, the tumour recurred, and a second complete resection was performed. Due to the early recurrence, she was placed on long-term MRI surveillance. At the age of 23, an enhancing left midbrain tumour was identified that was suspected to be a recurrent pilocytic astrocytoma. Following surgical resection the histopathology revealed a gliofibroma. Due to the growth of further tumour nodules she was treated with fractionated radiotherapy. There is no disease recurrence after 36 months of follow-up, and the patient remains well. DISCUSSION: Gliofibromas are tumours which usually occur in childhood; this case report identifies a rare occurrence in an adult. The childhood intraventricular pilocytic astrocytoma was in an anatomically distinct location to the midbrain gliofibroma. Radiotherapy can control these tumours, and follow-up is required to understand the long-term outcome and prognosis.

The impact of MGMT methylation and IDH-1 mutation on long-term outcome for glioblastoma treated with chemoradiotherapy.

BACKGROUND: Increasingly, biomarkers have been identified that correlate with improved overall and progression-free survival (OS and PFS) in glioblastoma, including MGMT methylation status and mutations in the IDH1 gene. In this study, we investigated the clinical and biological factors associated with long-term survival in glioblastoma patients treated with chemoradiotherapy. METHOD: Demographic and clinical data were collected for all patients with glioblastoma diagnosed between May 2004 and September 2007, treated with chemoradiotherapy and with associated tissue samples available for biomarker analysis. MGMT methylation was determined by pyrosequencing. IDH1 mutation was identified by R132H immunohistochemistry. Univariate Cox regression analysis of factors associated with survival and Kaplan-Meier survival analysis was performed using the SPSS statistics package. RESULTS: One hundred patients were included in the study. Median follow-up was 12.2 months (range 1.6-102.4). Median OS was 12.1 months (95 % CI: 10.8-13.3) and median PFS was 8.2 months (95 % CI: 6.8-9.5). The 2-, 3- and 5-year survival was 18, 9 and 6 % respectively. Three patients are still alive at 7.4, 8.3 and 8.5 years after diagnosis. Cox proportional-hazards regression identified independent prognostic factors for OS, female (p = 0.019), MGMT methylation (p < 0.0001) and IDH1 mutation (p = 0.023), and for PFS, MGMT methylation (p = 0.001) and IDH1 mutation (p = 0.018). Kaplan-Meier survival analysis showed that MGMT(methylated)/IDH1(+ve) was associated with a significantly longer OS 66.8 months (95 % CI: 0.0-167.8) and PFS 16.9 months (95 % CI: 11.1-22.7) when compared with MGMT(methylated)/IDH1(-ve) OS 15.5 months (95 % CI: 11.6-19.4) and PFS 9.4 months (95 % CI: 8-10.8) (log-rank, P = 0.000) and MGMT(unmethylated)/IDH1(-ve) OS 11.1 months (95 % CI: 8.5-13.7) and PFS 6.3 months (95 % CI: 4.4-8.3) (log-rank, p = 0.000). CONCLUSIONS: While the importance of MGMT methylation is well established, we demonstrate that the combination of MGMT(methylated)/IDH1(+ve) is associated with considerably longer OS and PFS in this series of chemoradiotherapy-treated glioblastoma tumours. The long-term cognitive function and quality of life in these long-term survivors warrant investigation.

Transoral laser microsurgery for oropharyngeal squamous cell carcinoma: A paradigm shift in therapeutic approach.

BACKGROUND: The contemporary treatment of oropharyngeal squamous cell carcinoma (SCC) is an area of debate. We report outcomes of a minimally invasive approach involving transoral laser microsurgery (TLM). METHODS: A consecutive series of patients (n = 153) undergoing primary TLM for oropharyngeal SCC from 2006 to 2013 was studied. Human papillomavirus (HPV) status was determined by p16 immunohistochemistry and high-risk HPV DNA in situ hybridization. Survival analyses were evaluated using Kaplan-Meier statistics. RESULTS: Tumor subsites included tonsil (n = 94; 61.5%), tongue base (n = 38; 24.8%), and soft palate (n = 21; 13.7%), with the majority being American Joint Committee on Cancer (AJCC) stage III/IVa (n = 124; 81.0%) and HPV-positive (n = 101; 66.0%). Three-year overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were 84.5%, 91.7%, and 78.2%, respectively. HPV-positivity portended favorable oncologic outcomes. One-year gastrostomy tube (G-tube) dependency was 1.3%. CONCLUSION: To the best of our knowledge, this is the largest single-center TLM oropharyngeal SCC series to date. Our data suggest that TLM +/- postoperative radiotherapy (PORT) results in at least as good oncologic outcomes as chemoradiotherapy (CRT), while conferring swallowing function advantages. © 2016 Wiley Periodicals, Inc. Head Neck , 2016 © 2016 Wiley Periodicals, Inc. Head Neck 38:1263-1270, 2016.

Nuclear RNA-seq of single neurons reveals molecular signatures of activation.

Single-cell sequencing methods have emerged as powerful tools for identification of heterogeneous cell types within defined brain regions. Application of single-cell techniques to study the transcriptome of activated neurons can offer insight into molecular dynamics associated with differential neuronal responses to a given experience. Through evaluation of common whole-cell and single-nuclei RNA-sequencing (snRNA-seq) methods, here we show that snRNA-seq faithfully recapitulates transcriptional patterns associated with experience-driven induction of activity, including immediate early genes (IEGs) such as Fos, Arc and Egr1. SnRNA-seq of mouse dentate granule cells reveals large-scale changes in the activated neuronal transcriptome after brief novel environment exposure, including induction of MAPK pathway genes. In addition, we observe a continuum of activation states, revealing a pseudotemporal pattern of activation from gene expression alone. In summary, snRNA-seq of activated neurons enables the examination of gene expression beyond IEGs, allowing for novel insights into neuronal activation patterns in vivo.

Opsoclonus-myoclonus syndrome associated with a nasopharyngeal tumor in an adult: a case report.

INTRODUCTION: Opsoclonus-myoclonus syndrome is a rare autoimmune syndrome usually seen in children and very rarely in adults. It typically presents with a triad of opsoclonus, myoclonus and ataxia, and is most often associated with a tumor or after an infection or vaccination. Around half of all adult cases are paraneoplastic in origin, and isolated case reports include associations with lung, breast and ovarian cancers. To the best of our knowledge, this is the first-ever reported case of paraneoplastic opsoclonus-myoclonus syndrome occurring in association with a nasopharyngeal carcinoma. CASE PRESENTATION: A 50-year-old British Caucasian woman presented with left-sided otalgia and subjective hearing loss. Over the coming weeks she developed subacute confusion and dizziness, leading to recurrent falls. Her clinical examination revealed opsoclonus, myoclonus and signs of cerebellar dysfunction. Subsequent magnetic resonance imaging revealed a left-sided nasopharyngeal carcinoma, which was confirmed on biopsy. A tapering dose of steroids and a five-day course of intravenous immunoglobulins, followed by a combination of chemo-radiotherapy for the nasopharyngeal carcinoma, led to a significant clinical improvement. At six months follow-up she had no signs of focal neurological deficit, apart from the inability to tandem walk. We believe that the typical clinical features, presence of a tumor and response to treatment support a paraneoplastic aetiology. CONCLUSIONS: We show that a nasopharyngeal carcinoma can be associated with adult onset opsoclonus-myoclonus syndrome. Both neurologists and otorhinolaryngologists must be aware of such a presentation. Prognosis of the syndrome depends on early and adequate management of the tumor, therefore prompt identification of the syndrome and the underlying tumor is essential.

Linear accelerator radiosurgery for vestibular schwannomas: Results of medium-term follow-up.

BACKGROUND: To examine tumour control, via volume changes, and the complications of linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) treatment of vestibular schwannomas (VSs) on medium-term follow-up. METHODS: Between September 2003 and November 2009 fifty consecutive patients with VSs treated with SRS using a marginal dose of 12.5 Gy utilizing a LINAC equipped with a micro-multileaf collimator were identified. Evaluation included serial magnetic resonance imaging (MRI), and neurological and hearing examinations. RESULTS: The median tumour volume at treatment was 2.4 (range: 0.24-10.59) cm3. The intracranial diameter of the tumours ranged between 7.7 and 28.7 (median: 15.8) mm. Follow-up MRI was available for analysis on 49 patients. The median radiological follow-up period was 5.8 (range: 1.4-9.2) years. The median tumour volume at last follow-up was 1.1 (range: 0.03-5.3) cm3. VS decreased in size in 45 (90%) patients, with a median reduction in tumour volume of 1.46 (range: 0.06-9.29) cm3 or a median tumour size reduction of 59% of the baseline (range: 6-90%) in these patients. VS remained stable in 2 patients and increased in size in 2 patients. Only 1 patient (2%) required additional intervention (surgery). 15 patients had useful hearing pre-treatment; 10 post-treatment pure-tone audiograms of these patients were available. 5 (50%) patients still had useful hearing post treatment. Non-auditory adverse radiation effects included new (House-Brackmann grade II) or worsened facial nerve palsy (House-Brackmann grade II to grade V) in 2 (4%) patients and trigeminal sensory disturbance in 2 (4%) patients. CONCLUSIONS: At medium term, the vast majority of VSs treated with LINAC-based SRS exhibit tumour shrinkage. The slightly higher rate of facial nerve palsy compared with Gamma Knife surgery (GKS) results may be related to the learning curve. Other complications were similar to reported GKS results for VSs of comparable sizes.

Paediatric intracranial anaplastic ependymoma: the role of multiple surgical resections for disease relapse in maintaining quality of life and prolonged survival.

INTRODUCTION: Ependymoma is the third most common intracranial glioma in children. The treatment of choice for these tumours remains gross total resection followed by radiotherapy. There are two principal histological subtypes, namely classic (∼70%) and anaplastic (∼30%) ependymoma. CASE: We present the case of a 12-year-old girl with an anaplastic ependymoma of the left temporal lobe. She underwent initial image-guided resection following biopsy. A postoperative MRI showed a macroscopic resection. She subsequently relapsed and indeed had 11 local and distant relapses managed by 12 separate craniotomies and tumour resection, 4 courses of radiotherapy and chemotherapy. CONCLUSION: For patients with multiple relapses, surgery should be considered primarily to re-resect any symptomatic lesion. This case demonstrates that multiple tumour resections can be undertaken with limited morbidity for the patient and with maintenance of quality of life. Repeated focal irradiation can also be used to control the disease with limited morbidity.

Radiotherapy for a benign cause of cauda equina compression in a known case of breast carcinoma.

A woman underwent breast conservation surgery and axillary clearance for T1N1M0 breast carcinoma, followed by adjuvant chemotherapy, radiotherapy and hormone therapy. At 3-year follow-up she presented with lumbar back pain and developed bilateral lower limb weakness. MRI spine demonstrated an expansile lesion at L1 causing cauda equina compression. The mass, unusually, was centred on the spinous process; metastases typically involve pedicles. The patient underwent surgical decompression with complete resolution of neurological signs. Histology revealed Masson tumour (intravascular papillary endothelial hyperplasia), a benign vascular lesion. Pain recurrence 9 months later prompted imaging demonstrating recurrent mass. Preoperative embolisation and re-excision was undertaken for recurrent Masson tumour. Recurrence of these lesions is rare and it was felt residual disease was likely. Radiotherapy has been used in isolated cases; therefore, she was treated with adjuvant radiotherapy, the first reported case of radiation in management of extracranial Masson tumour, and remains well 3 years later.

Gene expression in oligodendroglial tumors.

BACKGROUND: Oligodendroglial tumors with 1p/19q loss are more likely to be chemosensitive and have longer survival than those with intact 1p/19q, but not all respond to chemotherapy, warranting investigation of the biological basis of chemosensitivity. METHODS: Gene expression profiling was performed using amplified antisense RNA from 28 oligodendroglial tumors treated with chemotherapy [26 serial stereotactic biopsy, 2 resection]. Expression of differentially expressed genes was validated by real-time PCR. RESULTS: Unsupervised hierarchical clustering showed clustering of multiple samples from the same case in 14/17 cases and identified subgroups associated with tumor grade and 1p/19q status. 176 genes were differentially expressed, 164 being associated with 1p/19q loss (86% not on 1p or 19q). 94 genes differed between responders and non-responders to chemotherapy; 12 were not associated with 1p/19q loss. Significant differential expression was confirmed in 11/13 selected genes. Novel genes associated with response to therapy included SSBP2, GFRA1, FAP and RASD1. IQGAP1, INA, TGIF1, NR2F2 and MYCBP were differentially expressed in oligodendroglial tumors with 1p/19q loss. CONCLUSION: Gene expression profiling using serial stereotactic biopsies indicated greater homogeneity within tumors than between tumors. Genes associated with 1p/19q status or response were identified warranting further elucidation of their role in oligodendroglial tumors.

Extensive neck node metastases (N3) in head and neck squamous carcinoma: is radical treatment warranted?

OBJECTIVE: Head and neck squamous cell carcinoma (HNSCC) patients with N3 neck disease at presentation are the minority. Prognosis for such patients is poor, but there is disagreement about which treatment policy is best adopted. The aim of this study was to identify which groups of patients are best offered radical treatment, examining factors of association, prognosis, and survival. STUDY DESIGN: Prospective cohort study. SETTING: Regional tertiary head and neck cancer unit. SUBJECTS AND METHODS: Data were collected prospectively from patients treated for HNSCC with N3 nodal disease between 1975 and 2005. The data collected included age, sex, tumor TNM stage, histological grade, treatment, and survival. Odds ratio was used to calculate whether each parameter was statistically significant. Tumor-specific and observed survival curves were also calculated. RESULTS: A total of 275 patients had N3 disease. Multivariate analysis confirmed that advanced disease at the primary site (odds ratio = 4.6, P = .0261) mitigated against curative treatment. Comparison of tumor-specific survival between curative and palliative treatment strategies suggests that aggressive treatment is associated with greatly improved survival (median survival = 1.45 years, 95% confidence interval [CI] = 1.23-1.67 years; 5-year survival = 26.6%, CI = 17.14%-36.06%) compared with those treated palliatively (median survival = 3.18 months, CI = 3.06-3.30 months; no 5-year survivors; P < .0001). CONCLUSION: A major factor in determining treatment strategies for N3 disease HNSCC is the extent of disease at the primary site. These data suggest that aggressive treatment of the neck improves survival and should be considered in these patients.

Management of cerebral metastasis: evidence-based approach for surgery, stereotactic radiosurgery and radiotherapy.

Brain metastases constitute a significant disease burden and have a major impact on morbidity and mortality. This review discusses the relative merits of open surgery, whole brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS), which have been used alone and in combination with varying degrees of success for the treatment of newly diagnosed brain metastasis. Treatment aims to provide disease control with a good quality of life, although prolonged survival may not always be achieved. Decision to treat is based on several prognostic factors including age, performance status and control of the primary cancer. The recently developed disease-specific graded prognostic assessment (DS-GPA) scales can aid in clinical decision making for individual patients. Whole brain radiotherapy remains the mainstay of treatment and provides effective palliation. Omission of WBRT results in worse local and distant control, though not survival. Local tumour control can be achieved by either resection of stereotactic radiosurgery (SRS). In long-term survivors WBRT may cause cognitive decline and SRS is being explored as an alternative method of disease control. Increasingly, quality of life and neuro-cognitive function are being used as end-points in clinical trials.

Gene expression in oligodendroglial tumors.

BACKGROUND: Oligodendroglial tumors with 1p/19q loss are more likely to be chemosensitive and have longer survival than those with intact 1p/19q, but not all respond to chemotherapy, warranting investigation of the biological basis of chemosensitivity. METHODS: Gene expression profiling was performed using amplified antisense RNA from 28 oligodendroglial tumors treated with chemotherapy (26 serial stereotactic biopsy, 2 resection). Expression of differentially expressed genes was validated by real-time PCR. RESULTS: Unsupervised hierarchical clustering showed clustering of multiple samples from the same case in 14/17 cases and identified subgroups associated with tumor grade and 1p/19q status. 176 genes were differentially expressed, 164 being associated with 1p/19q loss (86% not on 1p or 19q). 94 genes differed between responders and non-responders to chemotherapy; 12 were not associated with 1p/19q loss. Significant differential expression was confirmed in 11/13 selected genes. Novel genes associated with response to therapy included SSBP2, GFRA1, FAP and RASD1. IQGAP1, INA, TGIF1, NR2F2 and MYCBP were differentially expressed in oligodendroglial tumors with 1p/19q loss. CONCLUSION: Gene expression profiling using serial stereotactic biopsies indicated greater homogeneity within tumors than between tumors. Genes associated with 1p/19q status or response were identified warranting further elucidation of their role in oligodendroglial tumors.

Molecular genetics, imaging and treatment of oligodendroglial tumours.

The discovery of a genetic signature of chemosensitivity and prognosis in oligodendroglial tumours prompted a new optimism in glioma management. After more than a decade since the initial reports, where do we stand in the current management of oligodendroglial tumours? This review focuses on the latest molecular genetics, imaging characteristics, and recent trials of treatment paradigms for these tumours.

Phase II trial of intratumoral BCNU injection and radiotherapy on untreated adult malignant glioma.

DTI-015 (BCNU dissolved in ethanol) utilizes solvent facilitated perfusion (SFP) for intratumoral drug delivery. A phase II clinical trial of DTI-015 and fractionated external beam radiotherapy on newly diagnosed, malignant gliomas investigated early changes in tumour physiology and metabolism, clinical outcome and safety. Pre- and post DTI-015 injection neuro-imaging included computed tomography (CT) cerebral blood flow and volume, glucose and thallium single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Clinical status was determined before and after DTI-015, prior to radiotherapy and 3 monthly thereafter until progression (defined by Macdonald criteria). Primary endpoint was radiographic response. Secondary endpoints were progression free (PFS) and overall survival (OS). Twelve patients were enrolled; eight glioblastoma multiforme (GBM), four anaplastic astrocytoma (AA). Three days after DTI-015 injection, mean tumour blood flow (Paired t-test; P < 0.001) and blood volume (Paired t-test; P = 0.001) were significantly reduced. There was a significant decrease in glucose utilization (Paired t-test; P < 0.001) and thallium uptake (Paired t-test; P < 0.001) at 6 days. Tumour blood volume had a sustained reduction (Paired t-test; P = 0.001) at 26 days after DTI-015. There were two serious adverse events. Two patients with AA achieved a partial response. Median PFS was 39 weeks for AA and 27 weeks for GBM; median OS for GBM was 47 weeks and 132 weeks for AA. The imaging data forms a biological basis for understanding the effects of high dose BCNU delivered intratumorally by SFP, and suggests early effects on tumour vasculature and metabolism.

Survival of patients with neck recurrence following radical neck dissection: utility of a second neck dissection?

Treatment of neck recurrence following radical neck dissection is extremely difficult. Retrospective review of 699 radical neck dissections was performed. Recurrence rates, host, tumor, treatment factors, and survival were analyzed. One hundred nineteen patients who had undergone radical neck dissections had recurrence, 69 were considered candidates for salvage surgery. Factors that increased the risk of neck recurrence were neck node (N) status and no adjuvant radiotherapy. Factors associated with radical salvage treatment were young age, good general condition, and low recurrent N classification. Five-year survival for salvage neck dissection was 31%. Young patients and low T and N classification did well. Low recurrent N classification and salvage surgery were associated with good prognosis for recurrence. In our study, radical neck dissection has a regional failure rate of 20%, a third of recurrence cases were offered curative treatment. Of these, 31% were cured with salvage surgery.

Retinoblastoma gene abnormalities in early laryngeal cancer.

The retinoblastoma gene (Rb) is postulated to be important in carcinoma of the larynx. Its cellular protein (pRb) is involved in regulation of the cell cycle and may be influential in the cells response to irradiation injury. From the University of Liverpool Head and Neck Database we identified 35 patients with a T2 N0 laryngeal squamous carcinoma whom received primary irradiation and had a minimum of 5 years follow up. Laser capture microdissection was performed on paired normal and tumour biopsy material to analyse for loss of heterozygosity (LOH) and microsatellite instability (MI) of the Rb gene and immunohistochemistry (IHC) was carried out to detect pRb expression. Of 35 tumours, 13 were normal, 12 had MI and 5 had LOH of the Rb gene. Abnormalities at the Rb locus did not correlate with loss of pRb expression. There was also no significant difference between the distribution of normal and abnormal gene sequences and whether or not the primary laryngeal tumour recurred after radiotherapy. Rb gene abnormalities occurred in one third of T2 N0 laryngeal carcinomas. These were not in isolation predictive of cure by radiotherapy.