Sigmoid colon cancer is a malignant tumor that develops in one of the sections of the large intestine. Pathology is diagnosed more often in men aged 40 to 60 years, but women also suffer from it. Lack of timely treatment can be fatal.
What can cause the pathology?
If sigmoid colon cancer is diagnosed, the causes may be different, but most often it is an unhealthy diet and a sedentary lifestyle. With constipation, the risk of developing cancer increases, since the mucous membrane is regularly damaged and is in contact with carcinogens for a long time.
Risk factors also include heredity, polyps and other benign neoplasms of the large intestine, bad habits.
Stages and classification: main types
Depending on the histological origin, doctors distinguish:
Adenogenic cancer of the sigmoid colon. Most common. Pathology is characterized by the growth of the glandular epithelium of the intestine. There is a poorly differentiated, moderately differentiated and highly differentiated cancer of the sigmoid colon.
Mucous adenocarcinoma. It is a type of poorly differentiated adenogenic cancer, but consists of cells capable of secreting a large amount of mucus.
Cricoid cell carcinoma. It is rarely diagnosed, but differs in aggressiveness, has the ability to develop rapidly.
Tumors that grow inside the intestinal lumen are called exophytic. Infiltrative, or endophytic, cancer differs in that the neoplasm grows into the intestinal wall. Regardless of the type of tumor, in the absence of timely treatment, intestinal obstruction and other complications of sigmoid colon cancer may occur.
If sigmoid colon cancer is diagnosed, the classification also takes into account the stage of the disease. Doctors distinguish 4 main stages:
Stage 1 – malignant cells infect the mucous and submucous layer.
Stage 2 – the tumor grows into the entire thickness of the intestinal walls, but does not give metastases.
Stage 3 – the neoplasm significantly increases in size, while metastases are found in the nearest lymph nodes.
Stage 4 – the tumor has distant metastases.
Signs and symptoms
If sigmoid cancer develops, there are no early symptoms. The first signs appear when the tumor grows in size. The following symptoms may indicate the presence of a malignant neoplasm:
constipation is often followed by diarrhea;
excessive gas formation;
pain in the lower abdomen;
soreness during bowel movements;
foreign impurities (mucus, blood) in the feces.
Also, the patient’s appetite disappears, fatigue and rapid fatigability is observed, and the body temperature rises.
How is the diagnosis carried out?
In the early stages, a malignant tumor can be detected only during a preventive examination, since the pathology has no pronounced signs.
Diagnosis of sigmoid colon cancer includes a set of studies:
video colonoscopy – allows you to examine the intestine from the inside;
Ultrasound – helps to determine the size of the tumor and its exact localization;
laboratory tests – allow you to identify cell mutations for the correct selection of chemicals;
MRI or computed tomography – helps to identify metastases and the extent of their spread.
In difficult cases, PET-CT and other modern techniques can be used, a biopsy is performed with subsequent histological examination.
The main methods of treatment
In most cases, combined treatment for sigmoid colon cancer is used, in which surgery is combined with chemotherapy and radiation therapy. The volume of surgical intervention is determined by the extent of the spread of the tumor process. Resection of the sigmoid colon with nearby lymph nodes is often performed. With advanced stages, a two-stage operation may be required.
Chemotherapy and radiation therapy can be used before surgery to reduce the size of the tumor, and afterwards to destroy metastases. Diet is also necessary for sigmoid colon cancer.
If sigmoid colon cancer is found, the prognosis directly depends on the type of tumor and the stage of the disease. With stage 1-2 cancer, the 5-year survival rate is 85-93%, but with advanced oncology, the indicator decreases to 8-10%. With timely diagnosis and treatment, the patient has a high chance of completely defeating the cancer.