The rectum is the name given to the last 15 cm of the large intestine and cancers that develop here are called rectal cancer.
Although it can cause symptoms such as difficult defecation, rectal bleeding, thinning of the stool diameter, episodes of diarrhea or constipation, and the feeling of incomplete evacuation, it can also be detected in some patients during screening colonoscopies or other examinations such as tomography, MRI or PET-CT.
The main diagnostic method is colonoscopic examination. In colonoscopy, a biopsy is performed from the tumor tissue (piece removal), and a tissue sample is provided for pathological examination.
In addition, it can be understood whether the tumor is at a very early stage, as well as the presence of concomitant lesions in other parts of the large intestine or whether there is familial polyposis syndrome.
Before planning the treatment of rectal cancer, staging should be done as in every cancer patient. In staging of rectal cancer:
Pelvic magnetic resonance (MR) imaging (with a special angle to the rectum),
Upper abdomen MRI
Thorax (lung) tomography should be taken.
PET-CT is not routinely recommended for rectal cancer staging, it is only recommended for the evaluation of patients with suspected metastasis (spread, spread).
In patients without advanced disease (early stage), endorectal ultrasound (EUS/ERUS) can be used to evaluate the spread of the tumor on the rectal wall.
Although blood values coded as CEA and Ca 19-9 are not used in staging, it is recommended to be studied at the time of first diagnosis in order to predict the course of the disease and to follow up the recurrence after treatment.
Rectal cancer treatment is planned according to the tumor stage, as in every gastrointestinal tumor. Below you can see the main treatment options by stage:
-Colonoscopic intervention (endoscopic submucosal dissection – ESD)
-Transanal minimally invasive approach (intervention from the anal canal under vision with surgical instruments)
-Colorectal surgery (open, laparoscopic, robotic)
– Colorectal surgery (open, laparoscopic, robotic)
-Surgery after radiotherapy
-Radiotherapy ± Chemotherapy — Colorectal surgery — Chemotherapy
Stage 4: (Distant organ metastasis)
Additional treatments may be considered depending on the site of metastasis. In patients with only lung or liver metastases, if all can be removed, rectal surgery and removal of metastases can be planned simultaneously or at different times. In patients with peritoneal (peritoneal membrane) metastases, HIPEC (warm chemotherapy) can be applied together with cytoreductive surgery after chemotherapy or immediately after diagnosis. Even in case of simultaneous metastases in many regions, surgical interventions can be planned.
Treatment planning at all stages should be decided in the light of current scientific data and considering the characteristics of the patient and tumor in a multidisciplinary oncology council attended by colorectal surgeon, medical oncology, radiation oncology, pathologist, radiologist and other related branches.
The location of the rectum in the pelvis (hip bone) is a factor that complicates the surgery of rectal cancers. There are bladder and prostate in front of the rectum, vessels and nerves feeding the genital and urinary system on the sides, urinary tract (ureter), and many vessels located in front of the hip bone at the back. While efforts to stay away from these structures prevent possible injuries, the rectal sheath may rupture and lead to disruption of oncological surgical rules. On the other hand, cutting the rectal sheath too far to protect it may cause injury to the surrounding structures, resulting in additional surgeries, life-threatening serious bleeding or sexual and voiding dysfunctions.
Provided that all these surgical rules are followed, rectal cancer surgery can be performed with the traditional (open) method, laparoscopically or robotically.