Colon cancer is a very common illness in our field, but it has excellent therapeutic options and a high rate of recovery when the injury is located in the intestine.
It is advisable to perform systematic tests to detect colon cancer to all adults aged 50 or more, especially if any of their first-degree relatives suffer from colorectal cancer. This is due to the high frequency of this illness, the ability to identify high-risk groups, the slow development of the primary injuries, the better recovery during the first stages, and the relative simplicity and precision of the detection processes.
Among the groups with a frequent rate of colorectal cancer, we find those with hereditary conditions such as familial polyposis, HNPCC, variants I and II of Lynch syndrome or any history of ulcerative colitis or colic Crohn's disease.
All these conditions together are responsible of 10% to 15% of all colorectal cancers.
Among other conditions with higher risk, we can list any history of colorectal cancer or adenomas in first-degree relatives, and any history of breast, endometrial or ovarian cancer. These high-risk groups are responsible for 23% of all colorectal cancers.
The prognosis for colon cancer is related to the degree of penetration of the tumor through the intestinal wall and the presence or absence of nodal involvement and distant metastasis. These three characteristics are the basis for a classification system created for this illness. The presence of intestinal obstruction and the rupture of intestinal wall are signs with a less optimistic prognosis.
The standard treatment for patients with colon cancer is surgical tumor resection, as well as locoregional lymph nodes resection. In our Hospital, surgery is curative in 25% to 40% of patients with resectable hepatic and pulmonary metastasis.
The progresses made in surgical techniques and preoperative radiological technology has improved the selection of patients eligible for resection. In addition, the laparoscopic approach to these injuries offers a better postoperative comfort for patients in our Hospital, as well as better results in terms of postoperative morbidity and stay at hospital, without any incidence on survival.
In patients with rectum cancer, the surgical process and its objectives are not the same as the ones just described. However, the surgical technique (resection of the mesorectum) has a very important role for obtaining good results (tumor recurrence and survival). Resection of the mesorectum must be total in mid and low rectal tumors, and must extend at least 5 cm below it in high rectal tumors. A total mesorectal excision combined with colorectal or coloanal low stapled anastomosis avoids in many cases the need of abdominoperineal resection and the establishment of a permanent stoma with this procedure. Nonetheless, the risk of anastomotic dehiscence in this type of procedure in which the sphincter is preserved is quite high (>15%), so a temporary ileostomy is frequently necessary.
Due to the growing tendency to therapeutic failure in those areas close to the injury, the impact of the perioperative irradiation is higher in rectal cancer than in colon cancer. Both preoperative and postoperative radiotherapies are associated to a chemotherapy treatment.
This type of therapy increases the number of patients that can preserve the sphincter apparatus, reduce local failure, and improve the disease-free period without affecting the survival obtained in patients in stages II and III. Improvements in the planning and radiation techniques have made it possible to decrease complications related to radiotherapeutic treatment. These techniques use multiple pelvic fields, vertical position, customized bowel immobilization molds, bladder distension, visualization of the small bowel with oral contrast, and three-dimensional treatment planning.
Drugs such as 5-FU, capecitabine, oxaliplatin and monoclonal antibodies have proved their adjuvant efficacy in patients with stage III colon carcinoma. In stage II colon carcinomas, this efficacy has not been totally demonstrated.