Medical Care
Medical care is mainly based on endoscopic surveillance to detect the onset of polyposis. Consequently, surgery would prevent the development of colon cancer. However, in view of the increased risk for the development of other cancers, continued medical follow-up is required with a number of surveillance tests, as colectomy would only address the potential risk of colon cancer.
Failure to obtain a relevant family history of FAP and providing information to family members on their risk and need for follow-up screenings to prevent cancers can be considered medical negligence. At the same time, identifying an asymptomatic person at risk and needing a diagnosis and follow-up treatment could lead to denial of medical and life insurances. [20, 22, 23] Failure to adequately follow up and monitor for the development of other cancers (eg, rectal pouch, duodenum) may lead to legal problems. Surveillance programs are important.
During pregnancy, the rate of desmoid and adenoma development is increased in the mother, owing to endogenous growth factors. Definitive treatment should ideally be deferred until delivery, if possible. [19]
A number of drugs (eg, celecoxib, sulindac) have been used successfully to reduce the number and the size of polyps in patients with FAP. However, they are insufficient as a primary modality of therapy.
Endoscopic surveillance
Note the following:
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Flexible sigmoidoscopy should be performed every 1-2 years starting at age 10-12 years in patients with FAP to document the onset of polyposis.
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Sigmoidoscopic surveillance and ablation of any polyps in the retained rectum or ileal pouch should be performed every 3-6 months in patients with FAP who have undergone colonic (total or subtotal) resection. There is an increased risk for adenomas and carcinomas in the ileal pouch, as there is increased epithelial cell proliferation at this site as compared to the afferent ileal loop. [23, 24]
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Once polyps are detected, colonoscopic surveillance is recommended to remove large polyps in patients who have not had an operation. This is important because surgery (colectomy) is usually deferred until an appropriate psychological age is reached (usually late teenaged years to early twenties). However, if the polyps have advanced histologic features, then early surgery is recommended.
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Front- and side-view esophagogastroduodenoscopy should be performed every 1-3 years once the diagnosis is made and after surgical therapy. The front-view esophagogastroduodenoscopy allows for the detection of gastric and duodenal polyps. The side-view duodenoscope allows for the examination of the ampulla of Vater.
Drugs used in the treatment of FAP include sulindac and celecoxib
Note the following:
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Because of the association between cyclooxygenase 2 (COX-2) inhibitors (celecoxib is a member of this drug family) and coronary artery disease, celecoxib is no longer widely used.
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These drugs have no primary role as sole therapy for patients with FAP who have not had surgical therapy. However, in patients with FAP who have had colectomy with ileoanal anastomosis, sulindac or celecoxib may be beneficial in reducing the size and the number of adenomatous polyps in the remaining rectum.
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The use of other nonsteroidal anti-inflammatory drugs (NSAIDs) and similar drugs is being studied.
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Cancers of the rectum (in patients who have had subtotal colectomy with ileorectal anastomosis) have been reported despite treatment with sulindac and celecoxib therapy. Because of the inability to control polyps medically, eventual rectal resection is usually necessary. This is why subtotal colectomy with ileorectal anastomosis (IRA) is not the preferred surgical procedure.
Screening of family members of patients with FAP should begin by age 12 years. Flexible sigmoidoscopy every 1-2 years until the patient is aged 35 years is adequate, then every 3 years thereafter. Genetic testing may eliminate the need for surveillance in some family members.
Desmoid tumors (intra-abdominal) may respond to antiestrogen therapy (tamoxifen) and sulindac because estrogen appears to promote their growth.
Chemotherapy with doxorubicin and dacarbazine may be attempted if no response is observed with other therapies.
A randomized trial suggested potential for aspirin to reduce colorectal adenoma growth or development in patients with FAP. However, it was a small study and patients have to be closely monitored for adverse events. [26]
In a murine model, low-dosage ursodiol together with sulindac prevented adenomas with less toxicity than if each had been given alone in full dosage. Interestingly, one study looked at the role of ursodeoxycholic acid on duodenal adenomas in FAP but found no effect on the development of duodenal adenomas [27, 28]
Dietary considerations
Patients with colectomy often have a change in bowel habits, for which changes in diet can lead to vitamin-mineral deficiencies. Vitamin B-12 deficiency occurs from rapid intestinal transit, ileal resection, and ascending bacterial overgrowth. [19]
Surgical Care
Because of the diffuse nature of the polyposis and the inevitability of colorectal cancer, surgical therapy is ultimately required. Surgical therapy should be performed before the onset of cancer. [24]
Note the following:
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Colectomy with mucosal proctectomy and ileoanal pouch pull-through (proctocolectomy with ileal pouch-anal anastomosis/IPAA) is the procedure of choice at many centers. This procedure allows retention of the rectal function. Other options include subtotal colectomy with ileoanal anastomosis and total proctocolectomy with ileostomy.
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If medical therapy and endoscopic therapy do not control polyp growth, rectal resection may be needed in patients who have a retained rectum (such as in subtotal colectomy). Desmoid tumors may be resected with adequate margins. This generally is reserved for patients with ureteral or intestinal obstruction.
In a study to determine whether surgical treatment outcomes vary between patients with FAP (168 patients) and those with the sporadic form of the disease (110 patients), Johnson et al concluded that for both disorders, endoscopic and local surgical management of duodenal polyps are each followed by a high rate of local recurrence. [29, 30] Their results also indicated that for patients with either disease, definitive resection via pancreaticoduodenectomy, pancreas-sparing duodenectomy, or segmental duodenectomy are the best means of eradicating polyps and preventing carcinoma.
Pouchitis appears to be a common complication in patients with medically refractory FAP who undergo ileal pouch-anal anastomosis (IPAA). [31] In a retrospective cohort study of 113 patients with FAP who were treated with IPAA over 23 years (1992-2015), nearly one quarter (22.1%) developed pouchitis. In addition, affected patients appeared to develop pouch-related complications (56.0%) 3 months or later following the procedure. However, more than two thirds of patients treated for pouchitis (69.6%) responded well to antibiotic management. [31]
Outpatient follow-up
Adenomas of ileal pouch
It has been reported that following restorative proctocolectomy, the incidence of adenomas in the ileal pouch is high in patients older than 50 years and in those with more than 1000 polyps at colectomy. Moreover, terminal ileal malignancy appears not to follow the classic adenoma-carcinoma sequence. Additionally, adenomas were rarely found in the afferent loop. No relationship has been found between APC mutation and ileal pouch adenomas. [28, 32]
Educate patients about the need for cancer surveillance after colectomy. [17] Inform family members so that they may undergo screening.
Consultations
Consultations are recommended for the following:
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A gastroenterologist familiar with FAP should supervise follow-up care. This is important because appropriate surveillance should be pursued to detect and treat other cancers/complications of FAP after surgery.
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Appropriate genetic counseling for both the patients and their family members should be initiated. The patients and their family members should be made aware of the limitations of genetic testing and the associated consequences. Genetic counseling should be performed by someone familiar with FAP and the genetic tests available
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It has been reported that patients with incontinence after colectomy reported lower psychosocial functioning and experienced greater distress; these patients would benefit from added psychological interventions. [33]
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Colectomy specimen obtained from a patient with familial adenomatous polyposis. Note the presence of numerous synchronous adenomatous polyps lining the luminal surface.
