RECENT MODALITIES IN THE MANAGEMENT OF COLORECTAL CARCINOMA

Abstract

Colorectal cancer is the third most frequently diagnosed cancer in United States and has the second highest cancer-related mortality rate after lung cancer. Incidence of colorectal cancer increases with increasing socioeconomic status. Diets high in meat and fat, low in fruit and vegetables are associated with an increased risk of colorectal cancer. A number of groups have an increased risk of developing colorectal cancer. At highest risk are those with either of the dominantly inherited conditions familial adenomatous polyposis (FAP) and hereditary non polyposis colorectal cancer (HNPCC). Colorectal cancer may be present for a considerable time before it produces clinical symptoms. Common symptoms of colorectal cancer are rectal bleeding, change in bowel habit, weakness, malaise, weight loss and unexplained anemia. Several approaches are available for the detection of colorectal cancer, including physical examination, digital rectal examination, fecal occult blood testing, serum carcinoembryonic antigen, standard sigmoidoscopy, fiberoptic sigmoidoscopy, full colonoscopy, single and double contrast barium enema, PET scan, Endo Rectal Ultrasound (ERUS), CT & MRI scans. Goals in the successful treatment and cure of colorectal cancer are local control, restoration of intestinal continuity, and preservation of the anorectal sphincter, sexual function and urinary function as far as possible. There are many different surgical approaches for treatment of colorectal cancer including right hemicolectomy, extended hemicolectomy, transverse colectomy, left hemicolectomy, abdominoperineal resction, anterior resction with coloanal anastomosis and also local resction. Total mesorectal excision (TME) provides an adequate lymphadenectomy for rec¬tal cancer. Recently, laparoscopic procedures play an important role in the management of benign and malignant colorectal diseases as a result of a recent shift toward minimally invasive surgery. The laparoscopic approach offers several potential benefits over laparotomy, including an earlier return of bowel function, decreased hospital stay and better cosmoses. On the other hand, inadequate excision and increased morbidity are potential risks of a laparoscopic approach. Moreover, sphincter-saving procedures may be compromised because of the technical difficulty in performing stapled low rectal division with the laparoscopic approach, preoperative radiotherapy may also induce difficulties in pelvic dissection. Adjuvent and Neo Adjuvent therapy play an important role in treatment of colorectal cancer especially in rectal cancer because of the anatomic confines of the pelvic bones and sacrum. Radiation therapy uses high-energy rays that destroy cancer cells. After surgery for colorectal cancer, radiation can kill small deposits of cancer that may not be seen during surgery. If size and/or position of the tumour make surgery difficult, radiation may be used before surgery to shrink the tumor. Radiation also may be used to ease (palliate) symptoms if patient has advanced cancer causing intestinal obstruction, bleeding, or pain. The most commonly used chemotherapeutic agents are 5-fluorouracil (5-FU) or floxuridine (FUDR), alone or in combination with leucovorin, and irinotecan. There are a number of potential advantages for using neoadjuvant chemoradiation. They include the ability to deliver higher doses of chemotherapy with radiation. Advantages include downstaging the tumor, radiating tissues with a greater oxygen supply, not radiating the anastomosis. Patients are more likely to complete the course of radiation therapy because it precedes their surgical resection. Postoperative chemo and radiotherapy followed by early and regular follow up of patients after curative resection by tumor markers, imaging and lower endoscope are important to reach high cure rates.