Terri Berk

Familial Adenomatous Polyposis-Associated Thyroid Cancer : A Clinical, Pathological, and Molecular Genetics Study

We report two familial adenomatous polyposis (FAP) kindreds with thyroid cancer, harboring two apparently novel germlineAPC mutations. The clinical phenotype in the first kindred was typical of classical adenomatous polyposis, whereas the second kindred exhibited an attenuated adenomatous polyposis phenotype. There was a female predominance with a mean age of 34 years (range, 23-49) at cancer diagnosis. Multiple sections of four thyroid tumors from three FAP patients were analyzed in detail. Histological examination of thyroid tumors showed a range of morphological features. Some tumors exhibited typical papillary architecture and were associated with multifocal carcinoma; in others, there were unusual areas of cribriform morphology, and spindle-cell components with whorled architecture. Immunoreactivity for thyroglobulin and high molecular weight keratins was strong. Somatic APC mutation analysis revealed an insertion of a novel long interspersed nuclear element-1-like sequence in one tumor sample, suggesting disruption of APC. In three FAP patients, ret/PTC-1 and ret/PTC-3 were expressed in thyroid cancers. No positivity was observed for ret/ PTC-2. p53 immunohistochemistry was positive in only one section of a recurrent thyroid tumor sample. Our data suggest that genetic alterations in FAP-associated thyroid cancer involve loss of function of APC along with the gain of function of ret/PTC, while alterations of p53 do not appear to be an early event in thyroid tumorigenesis.

Overlapping spectra of SMAD4 mutations in juvenile polyposis (JP) and JP–HHT syndrome†

Juvenile polyposis (JP) and hereditary hemorrhagic telangiectasia (HHT) are clinically distinct diseases caused by mutations in SMAD4 and BMPR1A (for JP) and endoglin and ALK1 (for HHT). Recently, a combined syndrome of JP–HHT was described that is also caused by mutations in SMAD4. Although both JP and JP–HHT are caused by SMAD4 mutations, a possible genotype:phenotype correlation was noted as all of the SMAD4 mutations in the JP–HHT patients were clustered in the COOH‐terminal MH2 domain of the protein. If valid, this correlation would provide a molecular explanation for the phenotypic differences, as well as a pre‐symptomatic diagnostic test to distinguish patients at risk for the overlapping but different clinical features of the disorders. In this study, we collected 19 new JP–HHT patients from which we identified 15 additional SMAD4 mutations. We also reviewed the literature for other reports of JP patients with HHT symptoms with confirmed SMAD4 mutations. Our combined results show that although the SMAD4 mutations in JP–HHT patients do show a tendency to cluster in the MH2 domain, mutations in other parts of the gene also cause the combined syndrome. Thus, any mutation in SMAD4 can cause JP–HHT. Any JP patient with a SMAD4 mutation is, therefore, at risk for the visceral manifestations of HHT and any HHT patient with SMAD4 mutation is at risk for early onset gastrointestinal cancer. In conclusion, a patient who tests positive for any SMAD4 mutation must be considered at risk for the combined syndrome of JP–HHT and monitored accordingly.

A germline mutation at the extreme 3' end of the APC gene results in a severe desmoid phenotype and is associated with overexpression of beta-catenin in the desmoid tumor.

Desmoid tumors arise sporadically or as part of the extraintestinal manifestations of familial adenomatous polyposis (FAP). In FAP, two distinct clinical presentations of the desmoid phenotype are seen: 1) one or a few desmoid tumors present predominantly in the abdominal wall or the abdomen; 2) a florid proliferation of tumors early in life, mostly near the axial skeleton or extremities. These different phenotypes have been associated with different sites of germline mutations in the adenomatous polyposis coli gene (APC gene). 
We present a large, French‐Canadian kindred with a florid desmoid tumor phenotype caused by a germline mutation at codon 2643‐2644 of the APC gene. The phenotype was characterized by the early onset of multiple tumors, arising near the axial skeleton and in proximal extremities. The penetrance of desmoid tumors was near 100% in this kindred. However, the expression of the disease was variable amongst the different affected relatives. Many gene carriers had cutaneous cysts. Polyposis of the colon was rarely observed in the affected individuals and we did not document upper gastro‐intestinal polyps. The mutant APC allele did not express a stable truncated protein in vivo. Molecular analysis of the probands tumor DNA revealed a somatic inactivating mutation of the wild‐type allele. Immunohistochemistry on the tumor also demonstrated elevated levels of beta‐catenin. 
The present study demonstrates that this extreme 3′APC mutation is associated with a severely penetrant desmoid phenotype and attenuated polyposis coli. It also suggests the involvement of the beta‐catenin pathway in the development of desmoid tumors in FAP. The natural history of the disease is variable between individuals, and surgical interventions have to be timed appropriately due to the frequent recurrences.

Comparison of ileal pouch-anal anastomosis and ileorectal anastomosis in patients with familial adenomatous polyposis

PURPOSE: The aim of this study was to evaluate the surgical complications and long-term outcome and assess the functional results and quality of life after ileorectal anastomosis and ileal pouch-anal anastomosis in patients with familial adenomatous polyposis. METHODS: From 1980 to 1997, 131 patients with familial adenomatous polyposis were operated on or were followed up or both at the Familial Gastrointestinal Cancer Registry at Mount Sinai Hospital. Demographic and operative data were prospectively collected in the ileal pouch-anal anastomosis group, and retrospectively in the ileorectal anastomosis group. A questionnaire or telephone interview or both were undertaken to evaluate functional outcome and quality of life. RESULTS: The ileorectal anastomosis group consisted of 60 patients (mean age, 31 years; mean follow-up, 7.7 years). In the ileal pouch-anal anastomosis group there were 50 patients (mean age, 35 years; mean follow-up, 6 years). There were no statistically significant differences with respect to anastomotic leak rate in ileal pouch-anal anastomosisvs. ileorectal anastomosis (12vs. 3 percent;P=0.21), risk of small-bowel obstruction (24vs. 15 percent;P=0.58), and risk of intra-abdominal sepsis (3vs. 2 percent;P=0.86). Reoperation rate was similar in the two groups (14vs. 16 percent;P=0.94). Twenty-one patients (37 percent) with ileorectal anastomosis were converted to ileal pouch-anal anastomosis (12 patients) or proctocolectomy (9 patients), because of rectal cancer (5 patients), dysplasia (1 patient), or uncontrollable rectal polyps (15 patients). Two pelvic pouches were excised, and another one was defunctioned. Information regarding functional results and quality of life was obtained in 40 patients (66.6 percent) in the ileorectal anastomosis group and in 43 patients (86 percent) in the ileal pouch-anal anastomosis group. Patients with ileorectal anastomosis had a significantly better functional outcome with regard to nighttime continence and perineal skin irritation. But otherwise, functional results and quality of life were similar. CONCLUSIONS: Although ileorectal anastomosis has a better functional outcome, ileal pouch-anal anastomosis may be preferable because of the lower long-term failure rate. Ileorectal anastomosis is still an option in patients with familial adenomatous polyposis with rectal polyp sparing and good compliance for follow-up.

Staging Intra-Abdominal Desmoid Tumors in Familial Adenomatous Polyposis: A Search for a Uniform Approach to a Troubling Disease

INTRODUCTIONDesmoid tumors are a clinical problem in 12 to 15 percent of patients with familial adenomatous polyposis. There is no predictably effective treatment for intra-abdominal desmoid tumors, which sometimes cause significant complications by their effects on the ureters or bowel. The relative rarity and the clinical heterogeneity of intra-abdominal desmoid tumors make randomized studies difficult to do. In this article a staging system is proposed to make multi-institutional studies easier.METHODSIntra-abdominal desmoid tumors can be staged according to their size, clinical presentation and growth pattern.CONCLUSIONA way of staging intra-abdominal desmoid tumors is proposed to facilitate stratification by disease severity during collaborative studies of various treatments.

Chemotherapy for desmoid tumors in association with familial adenomatous polyposis

PURPOSE: This study was designed to assess the effect of chemotherapy on complex desmoid tumors associated with familial adenomatous polyposis. METHODS: Five patients (3 males, 2 females; age range, 29–45 years) had symptomatic, unresectable intra-abdominal desmoid tumors in association with familial adenomatous polyposis that were unresponsive to conventional medical therapy. Each patient was treated with a cytotoxic chemotherapeutic regimen consisting of doxorubicin and dacarbazine followed by carboplatin and dacarbazine. Response to treatment was assessed by measurement of tumor size using computerized tomography. Follow-up has been for a mean of 22 (range, 10–30) months. RESULTS: One patient has had a complete response, and three patients have had a partial response, with a reduction in tumor volume of at least 50 percent. One patient had a minimum response to treatment and developed a rapid increase in tumor size on cessation of therapy. Complications of treatment included febrile neutropenia, severe epistaxis, and subclavian vein thrombosis. CONCLUSIONS: The cytotoxic chemotherapeutic regimen described is effective in the treatment of selected unresectable desmoid tumors associated with familial adenomatous polyposis and should be considered in symptomatic patients who do not respond to conventional medical therapy.

STK11/LKB1 germline mutations are not identified in most Peutz–Jeghers syndrome patients

Germline mutations of the STK11 gene mapped to chromosome 19p13.3 are responsible for Peutz–Jeghers syndrome (PJS), a dominant disorder associated with characteristic gastrointestinal hamartomatous polyps and a predisposition to various cancers. We conducted a detailed investigation of germline STK11 alterations by protein truncation test and genomic DNA sequence analysis in ten unrelated PJS families. We identified a novel truncating deletion spanning STK11 exons 2–7 in a single patient and several known polymorphisms. Loss of heterozygosity studies in PJS polyps of four of these patients identified an allelic deletion of D19S886 in another patient. Our results suggest that STK11 mutations account for only a proportion of PJS cases.

Extended follow-up of patients treated with cytotoxic chemotherapy for intra-abdominal desmoid tumors.

BACKGROUND: Cytotoxic chemotherapy can achieve a good initial response in inoperable desmoid tumors that have caused progressive obstruction of the gastrointestinal and urinary tracts and have caused unrelenting pain. METHODS: We have reviewed 8 patients (3 male) with desmoid tumors and familial adenomatous polyposis who underwent cytotoxic chemotherapy for inoperable gastrointestinal obstruction and/or uncontrolled pain. They were treated with doxorubicin and dacarbazine followed by carboplatin and dacarbazine. RESULTS: Follow-up after cytotoxic chemotherapy in the 7 patients for whom it was available was a mean of 42 (range 24–54) months. Two patients achieved complete remission after therapy. Four patients achieved a partial remission after completing all or some of the chemotherapy regimen; of these, three remained in stable remission, whereas the other was lost to follow-up. There were two recurrences that required further therapy; one of these patients was treated with further chemotherapy, which induced a second remission, and the other was treated with pelvic exenteration and has subsequently died. CONCLUSIONS: Most patients had a substantial response to cytotoxic chemotherapy; however, two patients required additional therapy 24 and 30 months after cytotoxic chemotherapy, respectively. Cytotoxic chemotherapy is effective in producing short-term and long-term remission in these difficult patients.

Genotype and phenotype of patients with both familial adenomatous polyposis and thyroid carcinoma.

The incidence of thyroid carcinoma in familial adenomatous polyposis (FAP) is thought to be 1%–2%, with the majority of cases being female. We have investigated the phenotype and genotype of 16 patients with FAP associated thyroid carcinoma. Among 1194 FAP patients studied in two high risk registries in North America (Familial Gastrointestinal Cancer Registry, Toronto and University California, San Francisco), 16 (1.3%) unrelated patients with FAP associated thyroid cancers were identified. Adenomatous polyposis coli (APC) gene testing was performed in 14 of the 16 cases. The average age of diagnosis for FAP and thyroid carcinoma was 29 years (range 17–52 years) and 33 years (range 17–55 years), respectively. All FAP patients except 1 had more than 100 colonic adenomas. Extracolonic manifestations, beside thyroid cancer, were presented in 81% (n = 13) of the patients, including gastric and duodenal polyps, desmoid tumor, osteoma, epidermoid cyst, sebaceous cyst and lipoma. Colorectal cancer was diagnosed in 38% (n = 6) of the patients. The pathology of the FAP associated thyroid cancer was predominantly papillary carcinoma. Germline mutations were identified in 12 of 14 patients tested. Mutations proximal to the mutation cluster region (1286–1513) were detected in 9 cases. Thyroid cancer in our FAP population was rare, predominantly in females and showed papillary carcinoma histology. Additionally, thyroid cancer in our patients occurred in the setting of classic FAP phenotype. Germline mutations were located predominantly outside the APC mutation cluster region.

Pathological features of colorectal carcinomas in MYH-associated polyposis.

Aims:  MYH is a DNA glycosylase in the base excision repair pathway. Germ‐line biallelic mutations in the MYH gene are associated with the development of multiple colorectal adenomas and colorectal carcinoma (CRC). A slightly increased risk of CRC is suggested in monoallelic MYH mutation carriers. The aim was to characterize the histopathological features of carcinomas from biallelics and monoallelics.