Efficacy Study of Chemoradiotherapy With or Without Paclitaxel in Squamous-cell Anal Carcinoma Patients

Inclusion Criteria: * Informed consent * Histologically verified squamous-cell anal cancer * Stage I-IIIB (Union for International Cancer Control (UICC) TNM classification v7) * Eastern Cooperative Oncology Group (ECOG) status 0-2 * HIV (Human Immunodeficiency Virus) negative * Haemoglobin (HGB) \> 90 g/L * Platelet Count (PLT) \> 120x10\*9/L * Serum creatinine \< 150 µmol/L * Total bilirubin \< 25 µmol/L Exclusion Criteria: * inability to obtain informed consent * distant metastases * synchronous or metachronous tumors * previous chemotherapy or radiotherapy * clinically significant cardiovascular disorders (myocardial infarction \< 6 months before visit, stroke \< \< 6 months before visit, instable angina \< 3 months before visit, arrhythmia, uncontrolled hypertension \> 160/100 mm hg * clinically significant neurological disorders * previous neuropathy 2 or higher * current infection or heavy systemic disease * pregnancy, breastfeeding * ulcerative colitis * individual intolerance to treatment components * proven dihydropyrimidine dehydrogenase (DPD) deficiency * participation in other clinical trials * psychiatric disorders, which render patient unable to follow instructions or understand his/her condition * technical inability to perform pelvic MRI * inability of long-term followup of the patient