Rectal cancer will be responsible for over 600,000 deaths across the world this year. In the event of cancer development, regualr screenings may help you catch the disease in an early stage.
One of the most common ways to identify a rectal cancer without performing any tests, without having an MRI or x-rays done, and without having a colonoscopy and without performing surgery, is to analyze the symptoms that the patient is suffering from.
To confirm the presence of rectal cancer, however, requires further evaluation. (see also: Colorectal Cancer Treatment)
Testing for Colorectal Cancer
Tests commonly used to diagnose rectal cancer include MRI, x-rays, colonoscopy, a digital rectal exam, fecal occult blood test and a sigmoidoscopy.
A sigmoidoscopy is a lighted probe that is inserted into the rectum and lower colon to check for polyps and other abnormalities.
A colonoscopy is a lighted probe that is inserted into the rectum and the entire colon to look for polyps and other abnormalities that may be caused by cancer. The advantage of using a colonoscopy is that if polyps are found during the procedure they can be removed almost immediately. Also, tissue may be removed for biopsy (the removal and examination of tissues).
DIGITAL RECTAL EXAM
A digital rectal exam is when a doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas. This type can only detect tumors that are large enough to be felt by the finger.
FECAL BLOOD TEST
A fecal occult blood test is when the doctor tests for blood in the stool.
CAT scans and virtual colonoscopies can also be used to help test for rectal cancer.
Overview of Staging
Staging of rectal cancer depends on the extent of local invasion, the degree of lymph node involvement, and whether there is distant metastasis. Definitive staging can only be done following surgery and the complete analysis of pathology reports.
Stages of Rectal Cancer
There are two primary staging systems for rectal cancer:
DUKES STAGING SYSTEM
The Dukes system classifies rectal cancer into:
Stage A: The tumor is confined to the intestinal wall.
Stage B: The tumor has invaded through the intestinal wall.
Stage C: The tumor has lymph node involvement
Stage D: The tumor has metastasized to other locations in the body.
TNM STAGING SYSTEM
The TNM system stands for tumors/nodes/metastases. This system assigns a number to go along with one of the three letters. The T stands for the degree of invasion of the intestinal wall, the N stands for the degree of lymphatic node involvement, and the M stands for the degree of metastases. For example:
T0: No evidence of tumor
Tis: Cancer in situ (tumor present, but no invasion)
T1: The tumor has inbvaded through the muscularis mucosa into submucosa.
T2: The tumor has invaded through submucosa into the muscularis propria (i.e. proper muscle of the bowel wall).
T3: The tumor has invaded through the muscularis propria into subserosa, but not to any neighbouring organs or tissues.
T4: The tumor has invaded beyond the muscularis propria into surround structures.
N0: No are lymph nodes involved.
N1: One to three nodes involved.
N2: Four or more nodes involved.
M0: No metastasis.
M1: Metastasis present.