Results of a prospective thyroid ultrasound screening program in adenomatous polyposis patients

Thyroid Nodules in Children With Familial Adenomatous Polyposis

INTRODUCTION

Ultrasound screening for thyroid cancer is recommended in familial adenomatous polyposis (FAP). This study investigated the prevalence of thyroid neoplasia in children with FAP.

METHODS

Cross-sectional study of children with FAP at an academic hospital. Clinical and ultrasound data were analyzed for the prevalence of thyroid nodules and cancer.

RESULTS

Of 37 children with FAP, 8 (22%) had thyroid nodules and 2 (5%) had thyroid cancer. Nodules (30%) and cancer (9%) were more common among female subjects and rare among male subjects.

DISCUSSION

Thyroid ultrasound screening in adolescence may benefit female subjects with FAP but has limited utility in male subjects.

Long-term clinical outcomes and follow-up status in Japanese patients with familial adenomatous polyposis after radical surgery: a descriptive, retrospective cohort study from a single institute

PURPOSE

Data on long-term outcomes of familial adenomatous polyposis (FAP) are unclear in Japan because a nationwide registry system is lacking. We assessed overall survival, incidence of neoplasms, fecal incontinence, and postoperative follow-up status of patients with FAP treated surgically in our hospital.

METHODS

In total, 154 patients with FAP who underwent radical surgery from 1981 to 2017 in our department were available for the questionnaire. Sixty-five patients, 36 of whom were followed at our hospital, were assessed using clinical records and the questionnaire.

RESULTS

The median follow-up time was 187 months (interquartile range, 93.5-296 months). The median age at surgery was 36 years (range, 12-69 years). The 5-, 10-, 15-, and 20-year overall survival rate was 100%, 98%, 95%, and 89%, respectively. All five deaths were caused by diseases other than colorectal cancer. FAP-related neoplasms comprised 23 colorectal cancers, five duodenal cancers, three gastric cancers, five thyroid cancers, two ileal pouch cancers, and nine desmoid tumors. The incidence of desmoid tumors was significantly associated with the operation date. The duration from radical surgery to neoplasm onset significantly differed by neoplasm type. Forty-five of 54 patients (excluding those who died or underwent ileostomy) developed fecal incontinence (median Wexner score of 8). Surgical procedures involving hand-sewn sutures with rectal mucosal stripping were significantly associated with fecal incontinence and the Wexner score. Fifty-eight of the 60 surviving patients underwent follow-up examinations.

CONCLUSION

Overall survival was favorable. Fecal incontinence depended on the surgical procedures. Most patients continued to receive follow-up examinations.

TRIAL REGISTRATION

No. 3112 by Institutional Review Board of Hyogo College of Medicine.

Screening for differentiated thyroid cancer in selected populations

The main purpose of cancer screening programmes should not be to detect all cancers, but to discover potentially fatal or clinically relevant cancers. The US Preventive Services Task Force recommends against screening for thyroid cancer in the general, asymptomatic adult population, as such screening would result in harms that outweigh any potential benefits. This recommendation does not apply to patients with symptoms or to individuals at increased risk of thyroid cancer because of a history of exposure to ionising radiation (in childhood, as radioactive fallout, or in medical treatment as low-dose radiotherapy for benign conditions or high-dose radiation for malignancy), inherited genetic syndromes associated with thyroid cancer (eg, familial adenomatous polyposis), or one or more first-degree relatives with a history of thyroid cancer. We discuss the evidence for and against screening individuals who are at high risk, and consider the different screening tools available.

Barriers to thyroid cancer screening with ultrasound in patients with familial adenomatous polyposis

OBJECTIVES/HYPOTHESIS

To identify barriers to care in patients with familial adenomatous polyposis (FAP) that have not undergone ultrasound for thyroid cancer (TC) screening.

STUDY DESIGN

Case series and survey.

METHODS

A study was conducted examining referral patterns for thyroid ultrasound (TUS) in FAP patients for TC screening. Patients with FAP seen at our institution were identified using International Classification of Diseases, Ninth Revision and Tenth Revision codes. Chart review was performed for TUS and the results were recorded. Patients and healthcare providers were surveyed to determine barriers to TUS and opportunities for improvement.

RESULTS

Thirteen out of 35 patients surveyed (37%) were told by a healthcare provider that TUS was recommended for TC screening. The incidence for TC in FAP patients ranges from 15 to 12%, whereas the general population risk is 0.02% to 1%. In our series, one patient of 12 (8%) had TC. Barriers to care included poor patient education about the risk of TC in FAP and miscommunication among specialties for referral for TUS. Also, patients enrolled in a FAP registry have improved care, as they are more likely to undergo TUS than those not enrolled.

CONCLUSIONS

FAP patients are at a higher risk of developing TC. Therefore, it is important for these patients to be informed and follow the recommended guideline to get a baseline TUS for screening as well as receive better patient education about the risk of TC and improved communication among specialties. Additionally, patients enrolled in a FAP registry are more likely to undergo ultrasound for TC screening, so there needs to be more centralized coordination for the multidisciplinary care of this disease.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:2436-2441, 2019.

Prevalence of and risk factors for thyroid carcinoma in patients with familial adenomatous polyposis: results of a multicenter study in Japan and a systematic review

PURPOSE

To investigate the recent Japanese prevalence of thyroid cancer and its characteristics in familial adenomatous polyposis (FAP) patients, through the development of surveillance programs.

METHODS

The subjects of this study were 282 (93.1%) FAP patients for whom information on thyroid cancer was available, from among 303 patients registered in "the Retrospective Cohort Study of Familial Adenomatous Polyposis in Japan" database. We evaluated the prevalence and risk factors for thyroid cancer and integrated and/or compared our findings with those of previous reports, using a systematic review, including a meta-analysis.

RESULTS

Thyroid cancer was diagnosed in 16 women (11.4%) and 2 men (1.4%), at 17-41 years and 39-57 years of age, respectively. The prevalence of thyroid cancer was 6.4%, with a female-to-male ratio of 8:1, which is comparable to reports from other countries. A young age of < 33 years at the FAP diagnosis and female gender were identified as independent risk factors for thyroid cancer.

CONCLUSIONS

FAP-associated thyroid cancer predominantly affects young women, both in Japan and other countries. Since FAP is generally diagnosed when patients are in their 20 s or older, regular screening for thyroid cancer is recommended for all FAP patients, but especially women, from their early 20 s.

Prevalence of thyroid diseases in familial adenomatous polyposis: a systematic review and meta-analysis

Thyroid cancer (TC) is a known extra-intestinal manifestation and contributes to the mortality and morbidity in patients with familial adenomatous polyposis (FAP). Its exact prevalence is not well established and recent studies have shown an increasing number of TC in this patient population. The prevalence of benign thyroid masses and endocrinologic thyroid disorders are also poorly described. We conducted a systematic review and meta-analysis by using a random-effects model to characterize TC and estimated the prevalence of thyroid diseases in FAP patients. Twelve studies (n = 9821) were included. Pooled prevalence of TC, benign thyroid masses, and endocrinologic thyroid disorders in FAP were 2.6% [95% confidence interval (CI) 1.3-4.8], 48.8% [95% CI 33.8-64.0], and 6.9% [95% CI 4.5-10.3] respectively. Subgroup analyses revealed higher prevalence of TC in studies with fewer participants, studies that used screening ultrasound to diagnose TC, and studies that were published after 2002. TC diagnosis preceded the diagnosis of FAP in 34% of the patients. The means age at diagnosis of FAP and TC were 29 and 31 years, respectively. 95% of the patients were female and the most common pathology was of papillary subtype (83.3%). Most mutations (79.2%) were located at the 5' end of APC gene. In summary, benign thyroid disorders are common in FAP, yet, TC is an uncommon phenomenon. Certain patient subset, such as young female with APC mutation at the 5' end, might benefit from routine surveillance ultrasound.

FAP Associated Papillary Thyroid Carcinoma: A Peculiar Subtype of Familial Nonmedullary Thyroid Cancer

Familial Nonmedullary Thyroid Carcinoma (FNMTC) makes up to 5–10% of all thyroid cancers, also including those FNMTC occurring as a minor component of familial cancer syndromes, such as Familial Adenomatous Polyposis (FAP). We give evidence that this extracolonic manifestation of FAP is determined by the same germline mutation of the APC gene responsible for colonic polyps and cancer but also shows some unusual features (F : M ratio = 80 : 1, absence of LOH for APC in the thyroid tumoral tissue, and indolent biological behaviour, despite frequent multicentricity and lymph nodal involvement), suggesting that the APC gene confers only a generic susceptibility to thyroid cancer, but perhaps other factors, namely, modifier genes, sex-related factors, or environmental factors, are also required for its phenotypic expression. This great variability is against the possibility of classifying all FNMTC as a single entity, not only with a unique or prevalent causative genetic factor, but also with a unique or common biological behavior and a commonly dismal prognosis. A new paradigm is also suggested that could be useful (1) for a proper classification of FAP associated PTC within the larger group of FNMTC and (2) for making inferences to sporadic carcinogenesis, based on the lesson from FAP.

Cribriform-morular variant of papillary thyroid carcinoma: an indication to screen for occult FAP

Cribriform-morular variant (CMV) is a rare subtype of papillary thyroid carcinoma (PTC) that is associated with familial adenomatous polyposis (FAP). Given the high likelihood for multi-organ malignancies in FAP patients, this study explores the yield of diagnosing occult FAP among CMV-PTC patients. Institutional database was searched in order to identify patients with pathologically-confirmed CMV-PTC from 2000 to 2012. Medical records were reviewed, and clinical and pathological features were analyzed. Eleven cases of CMV were identified from 6,901 patients with PTC, for a prevalence of 0.16 %. All 11 patients were female. The median age at CMV-PTC diagnosis was 36 years (range 18-46). Two patients had pre-existing FAP at the time of PTC diagnosis. The other nine patients were referred for colonoscopy and/or genetic testing. Six patients underwent colonoscopy and one (17 %) was diagnosed with FAP based on polyposis phenotype and genetic testing. The mean age of patients at the time of CMV-PTC diagnosis was younger in the FAP group (23 years, range 18-34) than in the sporadic group (37 years, range 25-46). All three patients with FAP-associated CMV-PTC had multicentric tumors, while all five sporadic patients did not. Our study found that approximately one-sixth of patients with CMV-PTC may have occult FAP. Patients with FAP-associated CMV-PTC appear to be younger and more likely to have multicentric tumors than those with sporadic CMV-PTC. Due to the increased risk of malignancy in patients with FAP, patients with CMV-PTC should be referred for colonoscopy and/or genetic evaluation for FAP.