%0 Journal Article
%T Metastatic Squamous Cell Carcinoma of the Anus: Time for a Shift in the Treatment Paradigm?
%A Alice Dewdney
%A Sheela Rao
%J ISRN Oncology
%D 2012
%R 10.5402/2012/756591
%X Anal cancers are rare tumours; however, the incidence is increasing in both men and women. Changing trends in sexual behaviour, smoking, and infection with the human papillomavirus are thought to be responsible for the increase. Patients with metastatic disease have a poor prognosis, with 5-year median overall survival rates of 10% in men and 20% in women. The standard systemic treatment of metastatic disease remains cisplatin and 5-fluorouracil, and aside from several non-randomised small phase II trials there has been no real progress over the past two decades. Based on the efficacy of cetuximab in squamous cell carcinomas from other primary sites, there appears to be clinical rationale for evaluation of anti-epidermal growth factor inhibitors in anal squamous cell carcinoma. In order to facilitate research and implement more effective treatment strategies international collaboration in clinical trials incorporating tissue collection for biomarkers is essential. 1. Introduction Anal cancers are rare tumours; in the UK there are approximately 900¨C1000 cases diagnosed per year, and in the USA they account for 1-2% of all gastrointestinal cancers [1]. However, the incidence is increasing in certain populations with high-risk behaviour and in those with the human immunodeficiency virus (HIV) [2, 3]. One of the most well-known risk factors is the human papillomavirus (HPV), particularly HPV type 16, which is present in approximately 80% of patients diagnosed with anal cancer [4]. Other risk factors include smoking, increased number of sexual partners, sexually transmitted infections, a history of vaginal or cervical malignancy, other conditions associated with lowered immunity, for example, transplant recipients and those with anal inflammatory conditions. Eighty percent of anal cancers are squamous cell carcinomas (SCCs); other rarer types of histology include adenocarcinoma, basal cell carcinoma, and melanoma [5]. The majority of cases present with early-stage localized disease. In this setting combined modality treatment with chemoradiation remains the standard of care allowing sphincter sparing whilst reserving surgery for those with persistent or recurrent disease following treatment [6]. Based on the available data a radiation dose of at least 45¨C50£¿Gy in combination with MMC and 5FU is currently the most commonly employed regimen [7¨C10]. Early-stage disease (T1/T2 N0) is associated with a good prognosis [11]. However, the five-year overall survival for those with more locally advanced disease ranges from 40¨C80% and 10 to 20% of patients will develop
%U http://www.hindawi.com/journals/isrn.oncology/2012/756591/