Familial differentiated carcinoma of the thyroid: report of five pairs of siblings

Frequency of thyroid carcinoma and thyroid autoimmunity in first-degree relatives of patients with papillary thyroid carcinoma: A single center experience

OBJECTIVE: To evaluate the frequency of thyroid cancer and thyroid dysfunction in first-degree relatives of thyroid cancer patients, and to determine if there is a difference between familial and sporadic thyroid cancer. SUBJECTS AND METHODS: Fifteen first-degree relatives of seven families with at least two family members with thyroid cancer (TC) were compared with 128 first-degree relatives of 45 families with only one family member affected. Laboratory and ultrasound evaluation, fine-needle aspiration biopsy and thyroid surgery were used as normally done in clinical practice. RESULTS: Thyroid dysfunction was similar between the two groups. The frequency of TC and autoimmunity in the group that had two relatives with known thyroid cancer was higher, compared with the families that had sporadic thyroid cancer among their family members (40% vs. 2%, p = 0.0001). CONCLUSION: Frequency of TC increases when more than one member of the family is affected. These findings suggest that these relatives should be screened more frequently than individuals in families in which only one case of TC is observed.

Review Article: The Familial Counterparts of Follicular Cell—Derived Thyroid Tumors

The follicular cell—derived thyroid cancers (termed nonmedullary thyroid cancers—NMTCs) occur mostly sporadically, but intriguingly, NMTC has the highest familial risk among all cancer sites. This epidemiological observation is strengthened by the clinical occurrence of NMTC in familial aggregation (FNMTC) and by the detection of chromosomal loci in linkage with the disease phenotype. FNMTC loci have been proposed at 14q, 1q21, 19p13.2, 2q21, 8p23, 8q24, 1q21, and 6q22, but to date, no causative mutations have been linked to FNMTCs. In this review, the authors focus on the clinical, morphological, and molecular aspects that characterize familial tumors. Some morphological patterns may alert for a familial disease. FNMTCs share several of the somatic molecular changes associated with sporadic tumors. New genes affected by somatic changes have been disclosed within regions harboring FNMTC loci.

Increasing incidence of thyroid cancer in Basilicata: an Italian study

OBJECTIVE

In recent years many authors have reported an increase in thyroid cancer (TC) incidence in several countries. The cause of such phenomenon remains unclear.

DESIGN

This study was designed to estimate the incidence of TC in Basilicata, the smallest region of Southern Italy with a population of 596,546 people, between 2001 and 2004.

MAIN OUTCOME

A total of 302 cases of TC were identified. The annual incidence of TC changed over the years, from 10.0 per 100,000 people in 2001 to 15.7 per 100,000 people in 2004. The number of new TC cases per 100,000 people increased an average of 16% per yr. Median age at diagnosis was 49 yr. The most frequent histotype was papillary TC (PTC) (73.2%). In 20 (6.6%) patients with PTC, we identified at least one first-degree relative affected by differentiated TC.

CONCLUSIONS

The present study shows a high incidence of sporadic and familial non-medullary TC in Basilicata. The reason for this finding may be related to several factors discussed in the paper. Further studies evaluating the trends in the incidence of TC in Basilicata in the future could provide some answers for the potential pathogenetic hypothesis.

An Evidence-based Approach to Familial Nonmedullary Thyroid Cancer: Screening, Clinical Management, and Follow-up

Approximately 5% of nonmedullary thyroid cancers are of familial origin. When two or more family members are diagnosed with nonmedullary thyroid cancer in the absence of other known associated syndromes it is termed familial nonmedullary thyroid cancer (FNMTC). The genetic inheritance of FNMTC remains unknown, but it is believed to be an autosomal dominant mode of inheritance with incomplete penetrance and variable expressivity. FNMTC has been shown to be more aggressive and to have a worse prognosis than sporadic nonmedullary thyroid cancer. For example, studies have demonstrated that individuals with FNMTC have an increased risk of multifocal disease, local invasion, and lymph node metastases. These aggressive features appear to contribute to the higher recurrence rate and decreased disease-free survival seen in FNMTC patients compared to those with sporadic differentiated thyroid cancer. This article is an overview of the literature available in the English language discussing FNMTC. Critical questions regarding the screening, management, and follow-up of these patients are addressed with answers proposed based on the available literature. The quality of the evidence is ranked according to Sackett's criteria. Overall, the literature quality is somewhat limited, based on the low prevalence of FNMTC, the difficulty in identifying familial cases, the variable study designs, and limited long-term follow-up.

CONCLUSIONS

To date, the optimal clinical approach is yet to be established, but improved awareness and screening will permit earlier detection, more timely intervention, and hopefully improved outcomes for patients and their families.

On the prevalence of familial nonmedullary thyroid cancer in multiply affected kindreds

Clinical and genetic studies of familial nonmedullary thyroid cancer (FNMTC) have yielded conflicting results concerning the aggressiveness of the tumors, and uncertainty of their genetic makeup. In most reports of multiply affected families, the composition of the kindreds has favored families of 2 affected members. Using data for differentiated thyroid cancer (DTC) provided by the Surveillance Epidemiology and End Results (SEER) branch of the National Cancer Institute, and fine-needle aspiration data from Mayo Clinic, I found that the likelihood of 2 cases of sporadic DTC (RR) in a 9-member first-degree family was 1.25% of all DTC families, amounting to 39.4% of 306 multi-hit families reported in the literature. To study the remaining affected families I used the Bernouilli trials model of exact probability. The 60.6% of non-RR, multiply affected families are mostly concentrated in kindreds of 2 to 5 affected members. In 2-hit families, 62%-69% of affected members are sporadic (RR) cases. In families having 3 or more affected members, fewer than 6% have 1 or more sporadic (R) cases, and fewer than 0.15% have 2 or more. In families of 3 to 5 affected members, more than 96% of affected members have the familial (F) trait. Approximately 1 of 338 DTC cases carries the F-trait. Since approximately 40% of multiply affected member first-degree kindreds of DTC, and a significant majority of 2-hit families, are composed of clinically evident, sporadic cases only clinical and genetic investigations of FNMTC should center on families of 3 or more affected members.

A Greek family with a follicular variant of familial papillary thyroid carcinoma: TCO, MNG1, fPTC/PRN, and NMTC1 excluded as susceptibility loci

The familial form of nonmedullary thyroid carcinoma (FNMTC) has been recognized as a distinct clinical entity and is characterized by multifocality and a more severe phenotype than its sporadic counterpart. The majority of FNMTC pedigrees are small in size, show variable modes of inheritance, and may present with a variety of additional benign thyroid disorders. The existence of marked phenotypic differences between FNMTC families suggests that there is genetic heterogeneity. Recent studies have mapped a susceptibility locus for FNMTC at 2q21. This locus appears particular relevant to families with at least one case of the follicular variant of papillary thyroid cancer (fvPTC). We describe the clinical and pathologic characteristics of a large three-generation fPTC kindred, with two of the four PTC patients presented with the follicular variant of PTC. It is of interest the occurrence of PTC in three siblings within a period of 3 years. In addition, multinodular goiter (MNG) was diagnosed in seven individuals, lymphocytic thyroiditis in four, while one diagnosed with a benign adenoma. From the PTC patients, one had MNG and fvPTC, one MNG, lymphocytic thyroiditis and papillary pattern of PTC, one lymphocytic thyroiditis and fvPTC, and one MNG and papillary pattern of PTC. The inheritance pattern was autosomal dominant with incomplete penetrance and women were affected more frequently than men. Considering all PTC-affected individuals, the limit of detection (LOD) score we got for this family on 2q21 was 0.5. The low LOD score is caused by a PTC patient who does not share the affected haplotype, suggesting that maybe a new locus for PTC predisposition is present in this kindred. Linkage analysis also excluded TCO, MNG, and fPTC/PRN as susceptibility loci to FNMTC in this family.

A report of six cases of familial papillary thyroid cancer

AIMS

Familial occurrence of papillary thyroid cancer is uncommon. The purpose of this study was review our own experience in a series of 267 papillary thyroid cancers.

METHODS

We analysed the clinical records of 267 consecutive patients operated on for papillary thyroid cancer (PTC) in our hospital between June 1980-March 2000.

RESULTS

We identified a family history in three families (6 patients), which results in a 2.25% familial papillary thyroid carcinoma (FPTC) rate. Pathology findings revealed that the tumour was multifocal and bilateral in 2 patients. Lymph-node metastases were found in 4 patients. They are all alive with a mean time of follow-up of 74.3 months (range 2-120).

CONCLUSIONS

We recommend that patients with familial disease should be treated according to the disease stage and other risk factors, similar to those with sporadic differentiated papillary thyroid cancer. We encourage the further reporting and pedigree analysis to identify patients affected by FPTC.

Increased risk for nonmedullary thyroid cancer in the first degree relatives of prevalent cases of nonmedullary thyroid cancer: a hospital-based study

The genetic basis for nonmedullary forms of thyroid cancer (NMTC) is less well established than that of medullary thyroid cancer. However, epidemiological and family studies suggest that a proportion of NMTC may be due to inherited predisposition. To estimate the familial risk of thyroid cancer, we conducted a hospital-based case-control study at the Princess Margaret Hospital in Toronto, Ontario, Canada, and at 2 university hospitals in Montréal, Québec, Canada. We obtained pedigrees from 339 unselected patients diagnosed with NMTC and from 319 unaffected ethnically matched controls. Family histories of cancer were obtained from the cases and controls for 3292 first degree relatives of cases and controls. Seventeen cases (5.0%) and 2 controls (0.6%) reported at least one first degree relative with thyroid cancer. In relatives of patients with thyroid cancer, the incidence of any type of cancer (including NMTC) was 38% higher than in relatives of controls (incidence rate ratio, 1.4; 95% confidence interval, 1.1-1.7). The relative risk for thyroid cancer was 10-fold higher in relatives of cancer patients than in controls (incidence rate ratio, 10.3; 95% confidence interval, 2.2-47.6). Our findings suggest that hereditary or other familial factors are important in a small proportion of NMTC. Molecular studies are needed to determine the genetic basis of cancer susceptibility in these families.

Is familial non-medullary thyroid carcinoma more aggressive than sporadic thyroid cancer? A multicenter series

BACKGROUND

The aggressiveness of familial non-medullary thyroid cancer (FNMTC) has been a subject of debate. The purpose of the study was to determine whether FNMTC is more aggressive than sporadic thyroid cancer.

METHODS

A multicenter retrospective matched-case control study of FNMTC versus sporadic non-medullary thyroid cancer was conducted. Disease-free survival (time to recurrence) for both groups was compared.

RESULTS

Forty-eight familial cases were compared with 144 age-, gender-, and stage-matched controls. Patients with FNMTC had a significantly shorter disease-free survival compared with sporadic non medullary thyroid cancer. Patients with FNMTC who presented with evidence of distant metastasis, or who were from families with more than 2 thyroid cancer-affected members, had the worst prognosis. The available staging systems were less likely to predict the outcome in patients with FNMTC than in patients with sporadic non-medullary thyroid cancer unless one accounted for the strength of family history in the staging system.

CONCLUSIONS

FNMTC is more aggressive than sporadic non-medullary thyroid cancer. The best predictors of a poor outcome in patients with FNMTC are the number of family members affected by thyroid cancer and evidence of distant metastasis.

Reliability of fine-needle aspiration in patients with familial nonmedullary thyroid cancer

In this case-control study we describe how often thyroid cancers and occult cancers are diagnosed or not diagnosed by fine-needle aspiration (FNA) in patients with thyroid nodules and a family history of nonmedullary thyroid cancers (FNMTC). Our hypothesis is that patients with thyroid nodules and a family history of FNMTC seem to be similar to patients with thyroid nodules and a history of exposure to low-dose therapeutic radiation. Both have been reported to have multifocal thyroid neoplasms and malignant tumors are common. Cytological examination may therefore be less accurate. From 1979 to 1996, 27 patients from 24 families with FNMTC were examined histologically after a preoperative cytological examination in all of them. A positive cytology examination was defined when biopsy documented thyroid cancer. It was interpreted as a false-negative study when a benign diagnosis was made and thyroid cancer was present anywhere within the thyroid, including in areas sampled or not sampled by FNA and not palpable preoperatively. A randomized control group, matched for age and gender, contained 27 patients with papillary thyroid cancer without familial disease. In our study group, 25 patients were treated with total thyroidectomy, including 7 with neck dissection, and 2 by thyroid lobectomy. At final histological examination 17 of 27 patients (63%) in this study group had multiple nodules and 25 of 27 (92.6%) had thyroid cancer. Thyroid cancer was diagnosed by FNA in 22 of 25 patients (88%), with 3 (12%) false-negative biopsies due to sampling errors (thyroid cancer not in the index nodule), versus 1 (3.7%) false-negative biopsy in the control group. Two patients in the study group with benign nodules were accurately diagnosed. In patients with false-negative biopsies and a history of FNMTC, the cancer was situated in one or more small nodules. Only one cancer was occult (< 1.0 cm). One-third of the patients in our study group (33%) had a history of radiation; 44% of the irradiated group had a single nodule; 56% had multiple nodules. In the control group, 9 of 27 patients (33%) also had a history of radiation; 33% of the irradiated group had a single nodule, 67% had multiple nodules. In conclusion, the reliability of FNA in patients with FNMTC appears to be less accurate than it is for other patients because of the high incidence of multifocal thyroid cancer and coexistence of benign nodules. Patients with thyroid nodules and a family history of thyroid cancer are more likely to have thyroid cancer and because they also have more coexistent benign nodules, they must be followed closely or treated with total or near-total thyroidectomy.

Familial non-medullary thyroid carcinoma: pathology review in 27 affected cases from 13 French families

BACKGROUND AND OBJECTIVES

When familial non-medullary thyroid cancer (FNMTC) develops with no obvious associated pathogenetic factor, an inherited predisposition may underlie the process. The present study was conducted because detailed pathological findings are lacking in most series of FNMTC.

PATIENTS AND METHODS

Thirteen families comprising 27 cases of FNMTC were included (1.8% of differentiated thyroid carcinoma). The family relationship (20 F, 7 M; age 46 +/- 16 years; mean +/- SD) was 'siblings' in eight families, 'parent and child' in four and 'aunt and niece' in one. Careful pathological review of the thyroid tumours (papillary/follicular: 25/2, size: 16 +/- 11 mm) was performed.

RESULTS

Initial staging according to extension was as follows: grade I (n = 16), II (n = 2), III (n = 6), IV (n = 3). Fourteen tumours were papillary microcarcinomas (size: 8 +/- 2 mm). No tumour phenotype that may be considered specific for FNMTC was found when considering either age, pathological findings or tumour aggressiveness. Although rare events were found in both relatives of some families suggesting a putative 'familial' phenotype of FNMTC, this may be fortuitous.

CONCLUSION

Micro familial non-medullary thyroid cancers are more common than previously reported and further studies are required to be able to distinguish this subgroup from sporadic papillary microcarcinomas. The careful pathological review of the familial non-medullary thyroid cancer in this study does not seem to point to a distinct subgroup of familial differentiated thyroid carcinoma although the data are intriguing. Genetic studies are now required to investigate this issue.

Familial papillary thyroid microcarcinoma: a new clinical entity

BACKGROUND

Familial, non-medullary thyroid carcinoma is clinically more aggressive than the sporadic form. We wanted to find out whether papillary thyroid microcarcinoma also occurs in a familial pattern, and, if so, to identify specific clinical and prognostic features.

METHODS

We reviewed the clinical records of 119 patients with papillary thyroid microcarcinoma. Familial occurrence, together with clinical presentation, surgical treatment, pathological characteristics, and follow-up were recorded.

FINDINGS

We identified a family history of thyroid carcinoma in seven patients. The tumour was multifocal in five patients, bilateral in three, and vascular invasion occurred in three of the seven patients. Lymph-node metastases were found in four patients. Three patients had a recurrence and one patient with pulmonary metastases died within 11 months.

INTERPRETATION

We identified familial occurrence in 5.9% of cases of papillary thyroid microcarcinoma. The unfavourable behaviour in the familial form of papillary thyroid microcarcinoma suggests that radical treatment and careful follow-up are warranted.

Familial nonmedullary thyroid carcinoma: a meta-review of case series

Familial occurrence of nonmedullary thyroid carcinoma is extremely rare but this has been increasingly recognized over the recent years. Earlier reports of such occurrence were primarily confined to individuals with previous radiation exposure, history of familial adenomatous polyposis (Gardner's syndrome) or multiple hamartomas (Cowden's syndrome), or monozygotic twins. The author reviews 15 case reports/series of familial nonmedullary thyroid carcinoma available in the literature involving kindreds with no obvious associated pathogenetic factors as mentioned above. There were a total of 87 kindreds with 178 affected individuals available for analysis, with a male to female ratio of 1:2.2. The modal age group at diagnosis was 30-39 years in both gender groups. Papillary thyroid carcinoma constituted 91% of the cases, followed by follicular (6%) and anaplastic (2%) varieties. There was one case (0.5%) each of combined papillary and medullary thyroid carcinoma and Hurthle cell carcinoma, respectively. Six of the 15 series observed that patients with familial history generally have more aggressive tumour characteristics compared to the sporadic counterparts. The incidences of multifocality, local invasion, and distant metastases at diagnosis were 49, 32, and 5%, respectively. The incidences of locoregional recurrence, distant metastases, and deaths were 29, 10, and 5.4%, respectively, at a mean follow-up period of 11 years. The actual prognostic outcome of familial nonmedullary thyroid carcinoma is still unclear in view of the limited clinical data. Although several authors have advocated an aggressive approach in managing these patients, no conclusion can be reached on the basis of this review to support this position. The author recommends that patients with familial disease should be treated according to the disease stage and other risk factors, similar to those with spontaneously occurring well-differentiated papillary or follicular thyroid carcinomas. In addition, one might consider and perform follow-up of first-degree relatives with similar degree of caution as patients who have undergone head and neck irradiation in childhood.