Management Of Locally Advanced Rectal Cancer
Ali Rashad Abd El-Moniem El-Shaer;
Abstract
Colorectal cancer is currently the third most common cancer diagnosed in both men and women, and the third leading cause of cancer - related deaths in the united states. The lifetime risk of developing colorectal cancer is about 1 in 20 (5%).This risk is slightly lower in women than in men.
A locally advanced rectal cancer often describes a tumor extending beyond the rectal wall with infiltration to surrounding organs or structures, and/or perforation of the visceral peritoneum. It includes presence of lymph nodes and bulky T3 tumors with threatened circumferential margins or T4 tumors, tumors with growth onto the peritoneal surface.
A number of factors have been considered important in its causation; interplay between environmental factors and host susceptibility. Diet rich in red meat, alcohol intake, obesity, decreased physical activity are all factors increasing the risk of developing rectal cancer.
Colorectal carcinoma is a genetically heterogeneous disease, and a series of genetic events has been described in the evolution of colorectal carcinoma. Three major categories of genes have been implicated in carcinoma development which are Oncogenes, tumor suppressor genes and mismatch repair genes. The majority of patients of rectal cancer have no identifiable risk factors, and most rectal carcinomas are asymptomatic until late stage, when some partial obstruction occurs, causing abdominal pain or change in bowel habits.
The gross appearance of rectal cancer involves one of the following features; ulcerative carcinoma, scirrhous carcinoma, polypoid carcinoma, infiltrating carcinoma, Linitis plastica and colloid carcinoma, while the major histological type of rectal cancer is adenocarcinoma, which accounts for 90-95% of all large bowel tumors. Other rare variants of epithelial tumors include squamous cell carcinomas. Sometimes called adeno-acanthomas.
Rectal cancers can spread locally or distantly via lymphatic and venous systems. Dukes’ hypothesis: lymph node invasion and distant metastasis could occur after the tumor had extended through the bowel wall.
As regard signs of rectal cancer, patients with symptoms suggestive of rectal pathology should undergo abdominal examination, rectal examination and rigid sigmoidoscopy in the clinic which may reveal signs of anemia, palpable mass, sigmoidoscopic findings suggestive of tumor and help in differentiation of rectal cancer from other similar conditions.
Preoperative staging depends on the following guidelines (a) history, (b) physical examination, (c) laboratory investigation as biochemical tests (serological markers that allow detection of rectal cancer as CEA, CA19-9), (d) special work up as pre-operative chest radiograph, computed tomography(CT)scan, endorectal ultrasound and MRI. For the vast majority of rectal carcinomas, MRI is currently the most accurate modality on which to base treatment decisions for patients with rectal cancer. While during operations diagnosis depending on taking biopsies either open or preoperatively by endoscope.
The proper treatment of patients with locally advanced rectal cancer is the multimodality therapy (chemotherapy, radiotherapy, surgery) which is the treatment of choice. Historically, surgery alone in this high-risk group resulted in an unacceptably high rate of local recurrence; pelvic recurrence occurs in approximately 30-65% when surgery alone was performed.
A locally advanced rectal cancer often describes a tumor extending beyond the rectal wall with infiltration to surrounding organs or structures, and/or perforation of the visceral peritoneum. It includes presence of lymph nodes and bulky T3 tumors with threatened circumferential margins or T4 tumors, tumors with growth onto the peritoneal surface.
A number of factors have been considered important in its causation; interplay between environmental factors and host susceptibility. Diet rich in red meat, alcohol intake, obesity, decreased physical activity are all factors increasing the risk of developing rectal cancer.
Colorectal carcinoma is a genetically heterogeneous disease, and a series of genetic events has been described in the evolution of colorectal carcinoma. Three major categories of genes have been implicated in carcinoma development which are Oncogenes, tumor suppressor genes and mismatch repair genes. The majority of patients of rectal cancer have no identifiable risk factors, and most rectal carcinomas are asymptomatic until late stage, when some partial obstruction occurs, causing abdominal pain or change in bowel habits.
The gross appearance of rectal cancer involves one of the following features; ulcerative carcinoma, scirrhous carcinoma, polypoid carcinoma, infiltrating carcinoma, Linitis plastica and colloid carcinoma, while the major histological type of rectal cancer is adenocarcinoma, which accounts for 90-95% of all large bowel tumors. Other rare variants of epithelial tumors include squamous cell carcinomas. Sometimes called adeno-acanthomas.
Rectal cancers can spread locally or distantly via lymphatic and venous systems. Dukes’ hypothesis: lymph node invasion and distant metastasis could occur after the tumor had extended through the bowel wall.
As regard signs of rectal cancer, patients with symptoms suggestive of rectal pathology should undergo abdominal examination, rectal examination and rigid sigmoidoscopy in the clinic which may reveal signs of anemia, palpable mass, sigmoidoscopic findings suggestive of tumor and help in differentiation of rectal cancer from other similar conditions.
Preoperative staging depends on the following guidelines (a) history, (b) physical examination, (c) laboratory investigation as biochemical tests (serological markers that allow detection of rectal cancer as CEA, CA19-9), (d) special work up as pre-operative chest radiograph, computed tomography(CT)scan, endorectal ultrasound and MRI. For the vast majority of rectal carcinomas, MRI is currently the most accurate modality on which to base treatment decisions for patients with rectal cancer. While during operations diagnosis depending on taking biopsies either open or preoperatively by endoscope.
The proper treatment of patients with locally advanced rectal cancer is the multimodality therapy (chemotherapy, radiotherapy, surgery) which is the treatment of choice. Historically, surgery alone in this high-risk group resulted in an unacceptably high rate of local recurrence; pelvic recurrence occurs in approximately 30-65% when surgery alone was performed.
Other data
| Title | Management Of Locally Advanced Rectal Cancer | Other Titles | الطرق المختلفة لتشخيص وعلاجأورام المستقيم المتقدمة | Authors | Ali Rashad Abd El-Moniem El-Shaer | Issue Date | 2017 |
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