Colorectal cancers are cancers that involve the large intestine (colon) and the rectum (the last part of the large intestine). Early diagnosis and correct treatment methods are of great importance in the course of the disease and the survival of the patient.
Colorectal cancers are the 2nd most common cancers in women and the 3rd most common cancers in men. While its risk of occurrence in the general population is 5%, the risk of developing cancer is 15-20% in patients with a family history of colorectal cancer, 15-40% in patients with inflammatory bowel disease, and 70-80% in patients with familial non-polyposis colorectal cancer mutation, and 100% in patients with familial adenomatous polyposis.
These risks increase with sedentary life, alcohol, smoking, and aging.
Risks are reduced with fiber consumption, consumption of vegetables and fruits, calcium, vitamin D, folic acid supplementation, exercise, and screening.
What are the symptoms of colorectal cancer?
They are initially not very obvious.
- Persistent diarrhea and constipation,
- A decrease in the thickness of stool, which has always been of standard thickness,
- Blood in the anus and stool,
- Egg white-like secretion in defecation,
- A sensation that the bowels cannot be emptied adequately,
- Painful defecation,
- Lack of appetite
- Severe abdominal pain
- Iron deficiency anemia,
- Weight loss,
- A sensation that there is a mass in the abdomen,
If those who have complaints of this kind see a doctor and have an early diagnosis before the disease progresses, their chance of survival will be significantly increased.
How is colorectal cancer diagnosed?
Patients with the above complaints are given an examination called colonoscopy, which allows us to look into the rectum and large intestine. If there is a mass in the large intestine or rectum, it is biopsied.
How is colorectal cancer treated?
After the diagnosis is made, staging is performed to determine the extent of the disease. For this purpose, the following tests are employed:
- Computed tomography (CT) of thorax and abdomen and pelvis
- Magnetic resonance imaging (MRI) of the abdomen and pelvis
In stage I, the disease is confined to the intestinal wall and has not yet spread to the lymph nodes, whereas in stage IV, it has spread to distant organs.
Treatment depends on the stage of the disease.
The treatment of colon and rectal cancer varies.
Colon cancer treatment
Treatment of colon cancer is surgery. Depending on the stage of the disease, chemotherapy may also be required. Radiotherapy is rarely required.
The intestinal tract with cancer is removed along with the vessels that supply it and the accompanying fatty tissue and lymph nodes. After the compromised area is removed, the remaining two intestinal ends are brought together and joined to each other using stitches or special tools, called a stapler meaning that this patient will continue to defecate frequently (through the anus).
However, in exceptional cases (such as an emergency, that the patient has a poor general condition), the two ends of the remaining intestine cannot be joined. In that case, the intestine is anastomized to the abdominal wall. Ostomy is the name given to this. The stool comes out into a collection bag that closes the ostomy. Mostly, these ostomies are temporary. At the end of the treatment, the intestines are joined together again.
Rectal cancer treatment
Depending on the stage of the disease, surgery, radiotherapy, and chemotherapy are often performed together.
Surgery is sufficient in stage I.
In stage II and III, chemotherapy and radiotherapy are generally recommended before surgery. This is called neoadjuvant chemoradiotherapy. Sometimes chemotherapy is continued after surgery.
In stage IV, mostly chemotherapy is applied. Sometimes surgery and radiotherapy may be required.
In some cases, short-term radiotherapy (5 days) is recommended instead of chemoradiotherapy before surgery.
The rectum and the veins that feed it and the fatty tissue, referred to as mesorectum, which contains the lymph nodes present along the veins, are removed. If the tumor extends to the anus, the anus is also removed. The remaining bowel opening is anastomized to the abdominal wall, and ostomy is opened.
Which methods are employed in colorectal cancer surgery?
Today, colorectal cancer surgery is performed by open, laparoscopic, and robotic methods.
Studies have shown that there is no significant difference between laparoscopic and open methods. With laparoscopy, the patient shows a faster recovery in a shorter amount of time and with less scarring.
Robotic surgical systems have started to be utilized in the treatment of colorectal cancer in recent years. The robotic arms used in robotic surgery can rotate tools up to 540 degrees, move quickly and without vibration in a narrow space and are assisted with a high-resolution image. In this way, it is especially useful in surgery performed in a very narrow area, e.g., in the case of rectal cancer. Protecting the nerves in rectal cancer surgery is vital in the continuation of sexual functions after surgery. Robotic surgical systems reduce the risk of nerve damage, especially in men and patients with a narrow pelvis.
How is colorectal cancer screening conducted?
Screening should be started after the age of 50 in individuals without complaints. For this purpose, fecal occult blood should be checked once a year; sigmoidoscopy should be performed every five years and colonoscopy every ten years. Colonoscopy can be performed every two years in the case of patients with high risk.
In individuals with a history of colorectal cancer or adenomatous polyp in first-degree relatives, the same procedures as in the case of average population should be started from the age of 40, whereas in individuals with first-degree relatives developing colorectal cancer at an early age, screening procedures should be initiated 5 years before the age of onset of cancer in their relatives.
Genetic tests should be performed after 10-12 years of age in families with familial polyposis syndromes, and screening should be performed with annual sigmoidoscopies and colonoscopies.
Genetic mutations should be investigated in patients with a family history of hereditary non-polyposis colorectal cancer. These patients should have colonoscopy once every 2 years as from the age of 20-25 years or 5 years before the age of onset of cancer in their family member and annual screening after the age of 40-45 years, female patients should have endometrial and ovarian examination once a year as from the age of 25-30, urine test and cervical smear follow up as from 5 years of age, dermal examination annually, GIT endoscopy once every 1-3 years.
What is the role of robotic systems in colorectal surgery?
In the robotic surgery system, operations are performed through small holes made in the abdominal wall as in the case of laparoscopy in general surgery. This system consists of the console where the surgeon performs the surgery and the unit where the robot arms are placed next to the patient and the 3D (three-dimensional) display unit where the operation area is reflected on the screen. Surgical instruments used in the robotic system can rotate 540 degrees, thanks to a feature called 'endo wrist.' It provides mobility in narrow and confined spaces. The 2D image in laparoscopy is replaced by a 3D image in the robotic system. In laparoscopic surgery, the human handshakes, though slightly. With the precision mobility feature of the robotic system, this shaking is eliminated.
Robotic systems are successfully used in colorectal surgery in colon cancers, rectal cancers, diverticulitis, inflammatory bowel diseases (Crohn, ulcerative colitis), rectal prolapse.
Since particularly rectal cancer surgery is performed in a narrow space, these systems enable surgery to be performed more effectively in male patients with a narrow pelvis. Protecting the nerves in rectal cancer surgery is vital in terms of sexual dysfunction after surgery. The robotic system helps to protect these nerves thanks to both the mobility feature of the robotic arms in a confined space and the high-resolution image. The negative peripheral margin in rectal cancer surgery increases the long-term survival of the patient. Since the ability of motion of laparoscopic hand tools is limited in the pelvis, the peripheral surgical margin is provided more quickly because the surgery performed using robotic instruments is more comfortable.
It is challenging to conduct laparoscopic colorectal surgery in obese and morbidly obese patients. The rate of transition to opening is high. Excess adipose tissue causes the mesentery, which contains the vessels and lymph tissues feeding the large intestine and rectum, to be very thick. With the help of robotic images and hand tools, these thick tissues can be treated more effectively.