Biomedical subjects

Alan G Thorson

Publications and source records attributed to Alan G Thorson.

5 recordsLinked to original sources

PubMed2006

Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and the US Multi-Society Task Force on Colorectal Cancer.

Patients with resected colorectal cancer are at risk for recurrent cancer and metachronous neoplasms in the colon. This joint update of guidelines by the American Cancer Society and the US Multi-Society Task Force on Colorectal Cancer addresses only the use of endoscopy in the surveillance of these patients. Patients with endoscopically resected Stage I colorectal cancer, surgically resected Stages II and III cancers, and Stage IV cancer resected for cure (isolated hepatic or pulmonary metastasis) are candidates for endoscopic surveillance. The colorectum should be carefully cleared of synchronous neoplasia in the perioperative period. In nonobstructed colons, colonoscopy should be performed preoperatively. In obstructed colons, double-contrast barium enema or computed tomography colonography should be performed preoperatively, and colonoscopy should be performed 3 to 6 months after surgery. These steps complete the process of clearing synchronous disease. After clearing for synchronous disease, another colonoscopy should be performed in 1 year to look for metachronous lesions. This recommendation is based on reports of a high incidence of apparently metachronous second cancers in the first 2 years after resection. If the examination at 1 year is normal, then the interval before the next subsequent examination should be 3 years. If that examination is normal, then the interval before the next subsequent examination should be 5 years. Shorter intervals may be indicated by associated adenoma findings (see "Guidelines for Colonoscopy Surveillance After Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society"). Shorter intervals also are indicated if the patient's age, family history, or tumor testing indicate definite or probable hereditary nonpolyposis colorectal cancer. Patients undergoing low anterior resection of rectal cancer generally have higher rates of local cancer recurrence compared with those with colon cancer. Although effectiveness is not proven, performance of endoscopic ultrasound or flexible sigmoidoscopy at 3- to 6-month intervals for the first 2 years after resection can be considered for the purpose of detecting a surgically curable recurrence of the original rectal cancer.

Colectomy↗

PubMed2003

Response to preoperative chemoradiation in stage II and III rectal cancer.

PURPOSE: The purpose of this study was to determine whether a complete pathologic response after neoadjuvant therapy in rectal cancer patients improves disease control and survival. METHODS: The study reviewed Stage II and III rectal cancer patients treated with preoperative chemoradiation and resected for cure. Complete pathologic response was defined as no cancer in the resected specimen. The main outcome measures were cancer-specific and disease-free survival in patients achieving a complete pathologic response and a noncomplete pathologic response. Kaplan-Meier curves were evaluated using log-rank analysis. RESULTS: Eighty-nine rectal cancer patients received neoadjuvant chemoradiation followed by radical resection for cure. Twenty-one patients (24 percent) achieved a complete pathologic response. Median follow-up for the complete pathologic response group was 23.5 months and 31 months for the noncomplete pathologic response group. There were more Stage III patients in the noncomplete pathologic response group than the complete pathologic response group (P = 0.005). Complete pathologic response patients were less likely to receive postoperative adjuvant chemotherapy than noncomplete pathologic response patients (P = 0.004). Cancer-specific and disease-free survival were not statistically different between the two groups. However, a trend was noted toward improved survival and decreased recurrence in association with a complete pathologic response. CONCLUSION: Stage III patients were less likely to be in the complete pathologic response group than Stage II patients. Complete pathologic response patients were less likely to receive postoperative adjuvant chemotherapy than noncomplete pathologic response patients. Complete pathologic response after neoadjuvant chemoradiation for rectal cancer patients demonstrated a trend toward improved survival and decreased recurrence compared with noncomplete pathologic response patients.

Aged↗

PubMed2002

Long-term efficacy of dynamic graciloplasty for fecal incontinence.

PURPOSE: Patients with end-stage fecal incontinence in whom all standard medical and surgical treatment has failed or is not expected to be effective can be treated by dynamic graciloplasty. The aim of this study was to review the long-term efficacy data. METHODS: Success was defined as a greater than 50 percent decrease in the frequency of incontinent episodes. Measured physiologic parameters included enema retention time and the difference in resting and squeezing pressures with and without stimulation. Measured quality-of-life parameters included the Medical Outcomes Study Short Form 36 Health Status Questionnaire, a Fecal Incontinence TyPE Specification, the Zung Self-Rating Depression Scale, the "state" portion of the State-Trait Anxiety Inventory, and the Visual Analog Scale, which were administered at baseline and through follow-up. Independent monitors collected data as part of a multicenter trial for patients who underwent dynamic graciloplasty from May 1993 to November 1999. RESULTS: There were 129 patients entered in the study, 115 of whom met eligibility criteria and were included in the efficacy outcome analysis. Twenty-seven patients entered the study with a preexisting functioning stoma; the remaining 88 patients did not have a functioning stoma at the time of enrollment. Success was achieved in 62 percent of nonstoma patients at 12 months; these results were sustained at 18-month and 24-month follow-up assessments (55 and 56 percent, respectively). The success rate in the stoma patients increased from 37.5 percent (9 of 24 patients) at 12 months to 62 percent (13 of 21 patients) at 18 months and was 43 percent at 24 months (9 of 21 patients), which reflects the increased number of patients whose stomas were closed. Although the measured physiologic continence parameters generally improved, these changes did not correlate with continence outcome. The group of patients (stoma and nonstoma) who underwent dynamic graciloplasty showed statistically significant improvements in quality of life as measured by Medical Outcomes Study Short Form 36 physical function (P = 0.006) and social functioning (P = 0.02) assessment. CONCLUSIONS: Dynamic graciloplasty was successful in the majority of patients with end-stage fecal incontinence. This result was usually achieved by 12 months after surgery in patients who did not have stomas and by 18 months in patients who had stomas at the time of dynamic graciloplasty surgery. These various improvements conferred by dynamic graciloplasty persisted during the two-year follow-up.

Adolescent↗

PubMed2002

Anorectal physiology.

Anorectal physiology, as assessed in an ARP laboratory, can provide helpful information in the management of patients with constipation and bowel incontinence. Beyond the uses described in this review, however, the ARP laboratory is most useful in the research setting. In this setting the laboratory can expand our understanding of function associated with other disease states, including anal fissure, fistula-in-ano, inflammatory bowel disease, and postoperative states. The lab can also provide improved understanding of the complex interactions of the enteric nervous and gut hormone systems with the smooth and skeletal muscle systems. A part of the failure of the ARP laboratory to enjoy more clinical usefulness lies in a lack of standardization of test protocols for many of the tests. Secondarily, there is a lack of normative data from large numbers of normal patients [1]. Finally, there is the difficulty in reproducing tests in situations where the patient has significant potential to compensate for deficits through the recruitment of adjacent muscle groups and other maneuvers. There is also some reluctance on the part of clinicians to make use of the ARP laboratory if the testing is not readily available in their community. Although the tests themselves are not difficult to learn to administer, lack of familiarity with the testing process can act as a barrier to acceptance. This is particularly true for clinicians that are used to making clinical decisions without the added benefit of physiologic testing. Despite these obstacles, the role of the ARP laboratory in the management of complex anorectal disease is likely to grow in the years ahead.

Anal Canal↗

PubMedDate not supplied

Guidelines for colonoscopy surveillance after cancer resection: a consensus update by the American Cancer Society and US Multi-Society Task Force on Colorectal Cancer.

Patients with resected colorectal cancer are at risk for recurrent cancer and metachronous neoplasms in the colon. This joint update of guidelines by the American Cancer Society (ACS) and US Multi-Society Task Force on Colorectal Cancer addresses only the use of endoscopy in the surveillance of these patients. Patients with endoscopically resected Stage I colorectal cancer, surgically resected Stage II and III cancers, and Stage IV cancer resected for cure (isolated hepatic or pulmonary metastasis) are candidates for endoscopic surveillance. The colorectum should be carefully cleared of synchronous neoplasia in the perioperative period. In nonobstructed colons, colonoscopy should be performed preoperatively. In obstructed colons, double contrast barium enema or computed tomography colonography should be done preoperatively, and colonoscopy should be performed 3 to 6 months after surgery. These steps complete the process of clearing synchronous disease. After clearing for synchronous disease, another colonoscopy should be performed in 1 year to look for metachronous lesions. This recommendation is based on reports of a high incidence of apparently metachronous second cancers in the first 2 years after resection. If the examination at 1 year is normal, then the interval before the next subsequent examination should be 3 years. If that colonoscopy is normal, then the interval before the next subsequent examination should be 5 years. Shorter intervals may be indicated by associated adenoma findings (see Postpolypectomy Surveillance Guideline). Shorter intervals are also indicated if the patient's age, family history, or tumor testing indicate definite or probable hereditary nonpolyposis colorectal cancer. Patients undergoing low anterior resection of rectal cancer generally have higher rates of local cancer recurrence, compared with those with colon cancer. Although effectiveness is not proven, performance of endoscopic ultrasound or flexible sigmoidoscopy at 3- to 6-month intervals for the first 2 years after resection can be considered for the purpose of detecting a surgically curable recurrence of the original rectal cancer.

American Cancer Society↗