What is Colorectal Cancer?

Colorectal cancer is a problem where cancer cells form in the colon or rectum (the last parts of the digestive system). The colon, also known as the large intestine, forms the final part of the body's digestive system, acting as a transit area where waste accumulates and is expelled after the absorption of nutrients. The rectum is the final section of the large intestine and serves as the storage location for feces.

What are the Stages of Colorectal Cancer?

Colorectal cancer typically begins with the development of small tumors called polyps. These polyps can gradually transform into cancerous cells over time. If colorectal cancer is diagnosed in its early stages, it is one of the cancers with a high chance of successful treatment. However, when diagnosed in advanced stages, treatment options may be more complex, and the risk of the disease spreading can increase. Therefore, regular screening tests play a lifesaving role in detecting this cancer.

Who Gets Colorectal Cancers?

Colon and rectal cancer continue to rank third among the most common and deadliest cancers in both sexes. According to Professor Dr. Neşet Köksal, a General Surgeon, approximately 1.8 million people worldwide are diagnosed with this disease every year, with around 900,000 deaths attributed to it, according to World Health Organization figures. Highlighting a more concerning trend regarding this significant issue, particularly with an increased frequency observed after the age of 50, our general surgical specialist pointed out that recent research indicates that colorectal cancers now also pose a threat to young adults representing the post-1980s born Generation Y. "In a study comparing adults born in the 1950s to those born in the 1990s, the risk of colon cancer has doubled and rectal cancer risk has quadrupled.

Additionally, it has been noted that nearly one-third of rectal cancer patients are under the age of 55, suggesting the consideration of starting screening before the age of 50," he said. Our expert, providing information from the Ministry of Health, stated that in our country, approximately 20,000 individuals were diagnosed with colorectal cancers, defined as colon and rectum cancers, in 2018. Emphasizing the impact of both genetic and environmental factors on colorectal cancers and the importance of early detection in survival, he explained that the pathway to this lies in screening.

Risk Factors for Colorectal Cancers

General Surgery Specialist emphasized that there are both modifiable and non-modifiable risk factors for colorectal cancers, stating that age and family history are non-modifiable risk factors. He continued, "Ninety percent of diagnosed colorectal cancers occur after the age of 50, and every decade after this age doubles the risk. While the lifetime risk of developing colon cancer is around 5%, it increases to 12% in individuals with a first-degree relative with colon cancer. If two first-degree relatives have cancer, this rate triples to 35%. Although these are non-modifiable risk factors, it is important to be aware of the risk and undergo regular screenings."

It's Possible to Reduce Risk by Changing Lifestyle

"Our expert explains that dietary habits and lifestyle are modifiable risk factors for colon cancers. "For example, in developed countries such as Europe or North America, colorectal cancer is more prevalent. The main contributing factor to this outcome is incorrect dietary habits, with a higher consumption of fatty and low-fiber fast-food-style foods. This situation also leads to obesity, which is another risk factor for colorectal cancers. Conversely, the incidence of colon cancer is much lower in African countries because they have a diet rich in grains and vegetables. Additionally, it's important to note that a sedentary lifestyle is also a significant risk factor."

Symptoms of Colorectal Cancers

"Our General Surgery Specialist emphasized that rectal bleeding is one of the most important symptoms of colorectal cancers and provided the following information: "The large intestine, or colon-rectum, is approximately one and a half meters long, starting in the lower right abdomen and ending in the anus or rectum. Therefore, various complaints may be observed depending on the location of the tumor. These symptoms include rectal bleeding, changes in bowel habits lasting more than a few days, a feeling of incomplete evacuation and discomfort after bowel movements, abdominal bloating, cramping pain, gas or a feeling of restlessness, anemia, unexplained weight loss, weakness, and fatigue."

In cancers located in the first part or right side of the colon, anemia is an important indication, while in cancers located in the last part, or rectum, rectal bleeding from the anus, which we call rectal bleeding, may be the first symptom. If this bleeding occurs particularly outside of bowel movements, it should be considered a serious warning sign. Individuals experiencing such complaints, especially those over the age of 50 or even younger individuals with a family history of colorectal cancer, should undergo colonoscopic examination to understand the cause”

Diagnosis of Colorectal Cancers

Professor Dr. Köksal emphasized the importance of screening in colon cancer, as in breast and cervical cancers. "Because with early diagnosis in this disease, treatment success can reach up to 90%. However, as the stage progresses with late diagnosis, the success rate decreases," he said. He stated that the World Health Organization (WHO) includes colon cancer among the diseases that need to be screened for because it has been shown to reduce the mortality rate from the disease.

“Our expert emphasized the importance of screening in this regard, but also highlighted the need for careful evaluation of the variety of screening tests, their feasibility, associated costs, and ensuring they are administered to the correct target population," he said. "In this regard, guidelines recommend annual examinations and fecal occult blood tests starting from the age of 40 for individuals with normal risk. Additionally, after the age of 50, sigmoidoscopy, which involves endoscopic examination of a portion of the colon, or colonoscopy, which allows visualization of the entire colon endoscopically, is recommended every 5 years and every 10 years, respectively. However, studies and recommendations have begun to suggest the need for earlier colonoscopic screening, such as at the age of 45, in line with the increasing frequency of the disease in individuals under the age of 50. Therefore, new criteria should be established, and risk-based screening algorithms based on age, gender, genetic risk, and lifestyle factors should be developed to enable personalized screenings in the future."

Treatment Methods for Colorectal Cancers

"Yeditepe University Koşuyolu Hospital General Surgery specialist, Prof. Dr. Neşet Köksal, emphasized the need to differentiate rectum cancers, which are the last part of the colon and large intestine close to the anus, in the treatment of colorectal cancers." Regarding the treatment approach, he provided the following information: "In colon cancers, if there is no organ spread, i.e., no metastasis, and if the tumor-containing part of the bowel can be surgically removed, the initial treatment for these patients is surgery.

After the removal of the relevant part of the colon, along with its leaf, in a procedure called mesocolic excision, pathological evaluation is performed. Considering the pathological staging and molecular characteristics of the tumor, the need for additional treatment is evaluated in collaboration with a medical oncologist. If the tumor is located in the rectum, the stage of the tumor, the patient's age, and general condition are taken into account in planning the treatment. In early-stage rectal cancers, treatment begins with surgery, followed by a decision on whether chemotherapy or radiotherapy is needed based on pathological evaluation. For rectal cancers that have not spread to other organs but have locally advanced, treatment typically begins with radiotherapy/chemotherapy, followed by the removal of the rectum leaf, known as mesorectal excision, after treatment.

During this procedure, we aim to preserve the anus as much as possible without compromising cancer surgery. In cases where rectal cancers completely disappear after drug and radiation therapy, close monitoring of these patients without surgery has emerged as an option. However, to consider this, it must be ensured that the tumor has responded fully to treatment, and follow-ups should be conducted at frequent intervals using appropriate methods. Nowadays, colorectal cancer surgery can largely be performed laparoscopically, or using minimally invasive techniques, by an experienced team. This allows patients to benefit from the advantages of laparoscopic surgery. It is also important to monitor these patients for recurrence after treatment completion.”