İstanbul Üniversitesi İstanbul Tıp Fakültesi Genel Cerrahi Anabilim Dalı
İstanbul Üniversitesi İstanbul Tıp Fakültesi Genel Cerrahi Anabilim Dalı
Colorectal cancer offers high cure rates with early detection. Prof. Dr. Hakan Yanar is an experienced surgeon in laparoscopic and robotic surgery, as well as HIPEC.
Colorectal cancer arises from the uncontrolled proliferation of cells lining the inner surface of the large intestine (colon) or its final section (rectum). As the 3rd most common cancer worldwide, colorectal cancer is a significant public health issue with approximately 15,000 new cases annually in Turkey.
The vast majority of colon cancers develop from adenomatous polyps. The malignant transformation of these polyps takes 5–15 years; this window demonstrates that it is a highly preventable and, with regular colonoscopy screening, early-stage curable cancer.
📌 Important: When diagnosed at Stage I, the 5-year survival rate exceeds 90%. Regular screening is the most critical factor determining this outcome.
Sudden severe abdominal pain, signs of bowel obstruction (severe distension, inability to pass gas/stool), or massive rectal bleeding necessitate immediate emergency room evaluation.
Colon cancer is frequently asymptomatic in its early stages. This makes regular screening imperative. The primary symptoms that present in advanced stages include:
Diagnosis is established via colonoscopy and biopsy. For staging, CT, MRI (especially for the rectum), and PET-CT are utilized; mutational analyses such as MSI/MMR, RAS, and BRAF guide treatment planning.
5-year survival data are based on the SEER database. Individual outcomes may vary depending on tumor biology, patient profile, and the experience of the treatment center.
Multidisciplinary tumor board decisions are definitive in colorectal cancer treatment. Prof. Dr. Hakan Yanar formulates a personalized treatment plan for each patient in coordination with surgical, medical, and radiation oncology teams.
Through 3–5 small incisions, this minimally invasive surgery removes the tumor-bearing bowel segment, surrounding tissue, and regional lymph nodes. Compared to open surgery, it provides less pain, a shorter hospital stay (3–5 days), a lower risk of infection, and a faster recovery.
Oncologically: Randomized trials report equivalent survival and local recurrence rates for laparoscopic methods compared to open surgery. Adequate lymph node dissection (≥12 lymph nodes) is performed as standard.
The da Vinci surgical system provides 3D HD visualization and tremor-free, precise movements. It offers significant advantages particularly in rectal cancer surgeries within the narrow pelvic cavity (total mesorectal excision — TME), enhancing sphincter and nerve preservation. Prof. Dr. Hakan Yanar holds a robotic surgery certification.
→ Detailed information on Laparoscopic & Robotic SurgeryIn cases of colorectal cancer with peritoneal dissemination, this is a heated chemotherapy (41–43°C) method applied simultaneously with cytoreductive surgery. With proper patient selection, it significantly prolongs survival. Prof. Dr. Hakan Yanar is one of the few expert surgeons in Istanbul with HIPEC certification.
→ Detailed information on HIPECIn rectal cancer, preoperative chemoradiotherapy shrinks the tumor, enabling sphincter-preserving surgery. It also reduces the risk of postoperative recurrence and lowers the need for a temporary or permanent stoma.
For mid and low rectal cancers, neoadjuvant chemoradiotherapy is the standard recommendation in current international guidelines. In cases achieving a pathological complete response (pCR), a 'watch & wait' protocol may be applied following a multidisciplinary board decision.
For Stage III colorectal cancer, FOLFOX (5-FU, leucovorin, oxaliplatin) or CAPOX (capecitabine + oxaliplatin) is administered for 6 months post-surgery.
In Stage IV cases, depending on RAS and BRAF mutation status and MSI/MMR profiling, bevacizumab, cetuximab, or pembrolizumab/nivolumab is added. If liver metastases are present and surgically resectable, curative-intent resection can be performed.
Patients are typically discharged 3–5 days after laparoscopic colon surgery. By implementing the ERAS (Enhanced Recovery After Surgery) protocol, postoperative pain, nausea, and hospital stay are minimized. A gradual transition to a normal diet occurs within 2–3 days.
Following discharge, patients can return to desk work in 2 weeks and resume normal physical activities in 3–4 weeks. Postoperative surveillance includes colonoscopy and CT scans every 3–6 months for the first year, followed by annual check-ups for 5 years.
Prof. Dr. Hakan Yanar is an experienced surgeon with over 50 international peer-reviewed publications in colon and rectal cancer surgery, practicing at Istanbul University Istanbul Faculty of Medicine and Liv Hospital Ulus. He works in coordination with a multidisciplinary tumor board, providing services to international patients in Turkish, English, French, and Russian.
Contact Prof. Dr. Hakan Yanar today for early diagnosis and treatment.
