They also justified the use of mitomycin in a definitive chemoradiation regimen for anal cancer despite greater toxicity, particularly in cases with large primary growths. Above the dentate line, the venous blood drains through the terminal branches of the superior rectal vein into the inferior mesenteric vein and portal system, and below the dentate line via the inferior rectal vein into the pudendal vein which itself drains into the internal iliac vein. As far as the etiology of anal adenocarcinoma is concerned, it is suggested that there occurs a multistep genetic sequence of events which lead to the transformation of normal mucosa to adenoma and finally carcinoma. Anal cancer is an uncommon type of cancer that occurs in the anal canal. Conformal therapy improves the therapeutic index of patients with anal canal cancer treated with combined chemotherapy and external beam radiotherapy. Cloacogenic carcinomas also called basaloid or transitional cell carcinomas are a type of squamous cell cancer.
Lymphatic mapping and sentinel lymph node biopsy in epidermoid carcinoma of the anal canal.
Since regression of anal canal cancers have been found to continue for up to three or more months after completing the treatment, it is recommended in literature that a biopsy should not be performed sooner than 3 months after the treatment, unless there is evidence of disease progression or other evidence to suggest early recurrence. The technique of sentinal lymph node biopsy to document nodal involvement in anal cancer was first reported by Kestgar MR et al in 66 and since than multiple studies 67 — 69 have proven the safety and reliability of this objective method in detecting micrometastasis in clinically unsuspicious nodes and thereby guiding individual therapeutic decisions in affected cases and avoiding treatment with associated morbidity in unaffected cases. Some changes in the anal mucosa are harmless at first, but might later develop into a cancer. Squamous cell carcinoma is the commonest lesion. Expression of c-ErbB-2 oncoprotein may play a role in promoting intraepithelial spread of cancer cells. Roach SC et al 61 found primary and recurrent tumours to be of high signal intensity relative to skeletal muscle on T2-weighted images, and of low to intermediate signal intensity on T1-weighted images. Most people with anal cancer are treated with a combination of chemotherapy and radiation.