Cutaneous malignancies in Indigenous Peoples of urban Sydney.

INTRODUCTION: Despite 3% of Australians identifying as Indigenous, cutaneous malignancies in these patients, including incidence, risk factors and outcomes have not been investigated. This is despite recognition that cancer outcomes in this population are significantly poorer. METHODS: We undertook a retrospective case series of Indigenous Peoples who presented to two urban cancer therapy centres for the management of cutaneous malignancies from 2003 to 2017. Risk factors, tumour-specific characteristics, treatments and outcomes were reviewed. RESULTS: Twenty-two patients identified as Aboriginal and/or Torres Strait Islander. The median age at presentation was 61 years and the majority were male (63.6%) and had skin phototype III (86.4%). Patients presented with basal cell carcinoma (50%), squamous cell carcinoma (31.8%), melanoma (9.1%) and cutaneous sarcomas (9.1%). The majority (68.2%) presented with stage II or higher disease, and there were high rates of immunosuppression (45.5%). At the time of reporting, 68.2% patients were alive, 18.2% had died from their skin cancers and 13.6% had died from unrelated causes. CONCLUSION: This cohort has demonstrated late-stage presentation of skin cancers, with substantial morbidity and mortality from potentially treatable cutaneous malignancies. This parallels other health conditions in Indigenous Australians and has highlighted the need for improved data collection of Indigenous status to better quantify the epidemiology of skin cancer in this population. There is an imperative to improve skin cancer awareness in this population to allow earlier detection and management to ensure better outcomes.

How important is dosimetrist experience for intensity modulated radiation therapy? A comparative analysis of a head and neck case.

PURPOSE: Treatment planning for IMRT is a complex process that requires additional training and expertise. The aim of this study was to compare and analyze IMRT plans generated by dosimetrists with varying levels of IMRT planning experience. METHODS AND MATERIALS: The computed tomography (CT) data of a patient previously treated with IMRT for left tonsillar carcinoma were used. The patient's preexisting planning target volumes (PTVs) and all organs at risk were provided with the CT data set. Six dosimetrists with variable IMRT planning experience generated IMRT plans according to the department's protocol. Plan analysis included visual inspection and comparison of dose-volume histogram, conformity indices, treatment delivery efficiency, and dose delivery accuracy. RESULTS: Visual review of the dose distribution showed that the 6 plans were comparable. However, only the 2 most experienced dosimetrists were able to meet the strict PTV aims and critical structure constraints. The least experienced dosimetrist had the worst planning outcome. Comparison of delivery efficiency showed that the number of segments, total monitor units, and treatment time increased as the IMRT planning experience decreased. CONCLUSIONS: Dosimetrists with higher levels of IMRT planning experience produced a better quality head and neck IMRT plan. Different planning experience may need to be considered when organizing appropriate departmental resources.

Use of cyclin D1 in conjunction with human papillomavirus status to predict outcome in oropharyngeal cancer.

There is increasing use of multiple molecular markers to predict prognosis in human cancer. Our aim was to examine the prognostic significance of cyclin D1 and retinoblastoma (pRb) expression in association with human papillomavirus (HPV) status in oropharyngeal squamous cell carcinoma. Clinical records and specimens of 226 patients with follow-up from 1 to 235 months postdiagnosis were retrieved. Tumor HPV status was determined by HPV E6-targeted multiplex real-time PCR/p16 semiquantitative immunohistochemistry and cyclin D1 and pRb expression by semiquantitative immunohistochemistry. Determinants of recurrence and mortality hazards were modeled using Cox regression with censoring at dates of last follow-up. The HPV-positivity rate was 37% (91% type 16). HPV was a predictor of recurrence, an event (recurrence or death) and death after adjustment for clinicopathological variables. There were inverse relationships between HPV status and cyclin D1 and pRb. On univariate analysis, cyclin D1 predicted locoregional recurrence, event and death and pRb predicted event and death. Within the HPV-positive group, after adjusting for clinicopathological factors, patients with cyclin D1-positive cancers had up to a eightfold increased risk of poor outcome relative to those with cyclin D1-negative tumors. However, within the HPV-negative group, there was only a very small adjusted increased risk. A combination of pRb and HPV did not provide additional prognostic information. Our data provide the first evidence that a combination of HPV and cyclin D1 provides more prognostic information in oropharyngeal cancer than HPV alone. If findings are confirmed, treatment based on HPV and cyclin D1 may improve outcomes.