Key Differences Between Colon Cancer and Rectal Cancer Surgical Care

Dr. Amalia Stefanou, a surgeon, in the Gastrointestinal Oncology Program at Moffitt Cancer Center discussed the key differences between colon and rectal cancer surgery.  

Q: What are the main surgical approaches for colon cancer?

A: The primary surgical approach for colon cancer is a partial colectomy, also known as a hemicolectomy or segmental resection. This procedure involves removing the segment of the colon containing the tumor along with surrounding lymph nodes and blood vessels. The two ends of the colon are then reconnected in an anastomosis.

Q: How does rectal cancer surgery differ from colon cancer surgery?

A: Rectal cancer surgery is generally more complex due to the rectum's location in the pelvis. The main surgical approach for rectal cancer is a total mesorectal excision (TME), which involves removing the rectum, surrounding mesorectal fat, and lymph nodes. Depending on the tumor's location, surgeons may perform an anterior resection, low anterior resection, or abdominoperineal resection.

Q: What factors influence the choice of surgical procedure for rectal cancer?

A: The choice of procedure depends on:

• Tumor location (high, mid, or low rectum)
• Tumor size and stage
• Proximity to the anal sphincter
• Patient's overall health and preferences
• For deficient rectal tumors, sphincter-preserving techniques may be considered to avoid a permanent colostomy3.

Q: How often is a permanent colostomy required in colon vs. rectal cancer surgeries?

A: Permanent colostomies are rarely needed in colon cancer surgeries. For rectal cancer, the likelihood of a permanent colostomy increases the closer the tumor is to the anus. Approximately 12.5% of rectal cancer patients require a permanent colostomy, compared to a much lower percentage in colon cancer patients.

Q: What role does neoadjuvant therapy play in rectal cancer treatment?

A: Unlike most colon cancers, locally advanced rectal cancers often receive neoadjuvant chemoradiation therapy before surgery. This approach aims to shrink the tumor, increase the likelihood of sphincter preservation, and reduce local recurrence rates.

Q: Are there differences in postoperative complications between colon and rectal cancer surgeries?

A: Rectal cancer surgeries generally have a higher risk of complications, including:

• Anastomotic leaks
• Sexual and urinary dysfunction
• Fecal incontinence

These risks are due to the rectum's proximity to pelvic nerves and organs. Colon cancer surgeries typically have lower rates of these specific complications.

Q: How does the approach to lymph node dissection differ between colon and rectal cancer surgeries?

A: In colon cancer, lymph node dissection follows the vascular supply of the affected segment. For rectal cancer, TME ensures the removal of the mesorectum, which contains the primary lymphatic drainage. This more extensive dissection in rectal cancer contributes to both improved oncologic outcomes and increased risk of complications3.

Q: What are the latest advancements in surgical techniques for colorectal cancer?

A: Recent advancements include:

• Laparoscopic and robotic-assisted surgeries for both colon and rectal cancers
• Transanal endoscopic microsurgery (TEM) for early-stage rectal tumors
• Sphincter-preserving techniques for low rectal cancers
• Watch-and-wait approach for complete clinical responders after neoadjuvant therapy in rectal cancer.

Q: How should primary care providers follow up with patients after colorectal cancer surgery?

A: Post-operative follow-up should include:

• Regular surveillance for recurrence (e.g., CEA levels, imaging)
• Monitoring for late complications (e.g., adhesions, incisional hernias)
• Psychosocial support, especially for patients with ostomies
• Lifestyle counseling to reduce the risk of recurrence.
• Coordination with oncology for adjuvant therapy when indicated.
• Providers should be aware that rectal cancer patients may require more intensive follow-up due to higher risks of local recurrence and functional complications.

Q: What are some of the key diagnostic distinctions between colon cancer and rectal cancer?

A: While colon and rectal cancers are both part of colorectal cancer, there are important differences in their diagnostic approaches:

For colon cancer:

• Staging is primarily determined through colonoscopy, CT scans, and pathology reports13.
• MMR (mismatch repair) status and other molecular markers like RAS and BRAF are assessed through genetic testing of biopsy samples.
• Pathology reports provide crucial information on tumor grade, depth of invasion, and lymph node involvement.

For rectal cancer:

• Diagnosis relies heavily on imaging, particularly CT scans and high-resolution MRI of the rectum.
• MRI is especially valuable for assessing the extent of local invasion, involvement of the mesorectal fascia, and lymph node status.
• Endorectal ultrasound may be used for early-stage tumors to evaluate depth of invasion.

Additionally, digital rectal examination is an important part of the initial assessment.

It's worth noting that advanced imaging techniques, such as specialized MRI protocols, can be particularly useful for evaluating complex or metastatic rectal cancer cases, allowing for more precise staging and treatment planning.

Q: Why refer your patients to Moffitt first?

A: Gastrointestinal cancers are among the most challenging cancers to treat. At Moffitt Cancer Center, our Gastrointestinal Oncology Program focuses exclusively on these unique malignancies such as colon and rectal cancers, allowing patients to receive care from some of the foremost experts in the field.

Moffitt is a National Cancer Institute-designated Comprehensive Cancer Center, recognized internationally for our commitment to innovation in research and treatment. When physicians refer patients to Moffitt, they are opening the door to leading-edge therapies, clinical trials, and individualized treatment plans. Through Moffitt's Gastrointestinal Oncology Program, patients not only have access to surgery, chemotherapy, and radiation therapy but also to innovative options, such as ablation, Y90 radioembolization, biological therapies, and even supportive care services to help improve their quality of life. Physicians can also submit referrals for patients without a confirmed diagnosis, as our advanced diagnostic program can help patients get the answers they deserve.

Moffitt Cancer Center holds a high-performing rating in gastroenterology & GI surgery, and colon cancer surgery by U.S. News & World Report in 2020. And, to ensure that every patient is obtaining the best possible therapies for his or her needs, our collaborative tumor board meets each week to review progress and adjust as necessary.

To simplify matters for referring physicians, we make it easy to send a patient to Moffitt’s Gastrointestinal Oncology Program. Referring physicians can complete our online form or contact a physician liaison for assistance.  We are prioritizing swift, comprehensive care, ensuring newly diagnosed colon and rectal cancer patients are seen within one week.