The goal of this clinical trial is to investigate total neoadjuvant therapy (TNT) using short course radiation therapy (SCRT) followed by full course of chemotherapy then surgery in locally advanced rectal cancer. The main questions it aims to answer are:

• Is total neoadjuvant treatment in this design safe & tolerable?
• Impact of this design on treatment related outcomes in terms of pathological and clinical responses.

Patients will be assigned to an experimental arm in which preoperative short course 5 x 5 Gy radiation therapy is followed by six cycles of combination chemotherapy (capecitabine and oxaliplatin) and surgery within 4-6 weeks

Inclusion Criteria:

• Histopathological proof of rectal adenocarcinoma.
• Tumors located within 15 cm and not less than 4 cm from anal verge.
• Age: ≥ 18 years.
• Locally advanced resectable rectal cancer (cT3/4 N0- Any T N+ve).
• ECOG Performance Status: 0-2.

Exclusion Criteria:

• Non-epithelial rectal malignancy such as sarcoma or lymphoma.
• Unresectable tumors in which surgery will never be possible even if substantial tumor downsizing is seen.
• Recurrent rectal cancer.
• Previous history of malignancy within the last 5 years.
• Previous pelvic irradiation.
• Psychiatric or addictive disorder that would preclude study therapy.
• Concurrent uncontrolled medical conditions.
• Pregnancy or breast feeding.
• Any contraindication to surgery.
• Extensive peripheral neuropathy.