Risk of thyroid cancer in first-degree relatives of patients with non-medullary thyroid cancer by histology type and age at diagnosis: a joint study from five Nordic countries.

Abstract

BACKGROUND:

We aimed to estimate lifetime cumulative risk of thyroid cancer (CRTC) in first-degree relatives of patients with non-medullary thyroid cancers (NMTC), including papillary (PTC)/follicular/oxyphilic/anaplastic thyroid carcinoma, by histology and age at diagnosis in patients and their relatives.

DESIGN:

A population-based cohort of 63 495 first-degree relatives of 11 206 NMTC patients diagnosed in 1955-2009 in Nordic countries was followed for cancer incidence. Standardised incidence ratios (SIRs) were calculated using histology-specific, age-specific, sex-specific, period-specific and country-specific incidence rates as reference.

RESULTS:

The 0-84-year CRTC in female relatives of a patient with PTC was 2%, representing a threefold increase over the general population risk (SIR=2.9, 95% CI 2.4 to 3.4; Men: CRTC=1%, SIR=2.5, 95% CI 1.9 to 3.3). When there were ≥2 PTC patients diagnosed at age <60 years in a family, CRTC for female relatives was 10% (male 24%). Twins had a 23-fold increased risk of concordant PTC. Family history of follicular/oxyphilic/anaplastic carcinoma increased CRTC in relatives to about 1-2%. Although no familial case of concordant oxyphilic/anaplastic carcinoma was found, familial risks of discordant histology types of NMTC were interchangeably high for most of the types, for example, higher risk of PTC when a first-degree relative had follicular (SIR=3.0, 95%CI 1.7 to 4.9) or anaplastic (SIR=3.6, 95% CI 1.2 to 8.4) carcinoma. The earlier a patient was diagnosed with PTC in a family, the higher was the SIR in his/her younger relatives. There was a tendency towards concordant age at diagnosis of thyroid cancer among relatives of PTC patients.

CONCLUSIONS:

This study provides clinically relevant risk estimates for family members of NMTC patients.

• Authors: Mahdi Fallah, Eero Pukkala, Laufey Tryggvadottir, Jörgen H Olsen, Steinar Tretli, Kristina Sundquist, Kari Hemminki
• Journal: Journal of medical genetics (J Med Genet) Vol. 50 Issue 6 Pg. 373-82 (Jun 2013) ISSN: 1468-6244 [Electronic] England
• PMID: 23585692 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adenocarcinoma, Follicular (diagnosis, epidemiology, genetics, pathology)
• Adolescent
• Adult
• Age Factors
• Aged
• Aged, 80 and over
• Child
• Child, Preschool
• Family
• Female
• Humans
• Incidence
• Infant
• Infant, Newborn
• Male
• Middle Aged
• Risk
• Scandinavian and Nordic Countries (epidemiology)
• Sex Factors
• Thyroid Neoplasms (diagnosis, epidemiology, genetics, pathology)
• Young Adult