Risk of thyroid cancer after exposure to fertility drugs: results from a large Danish cohort study

Abstract

BACKGROUND: Findings from the few epidemiological studies that have investigated thyroid cancer risk after fertility drugs have been inconclusive. Using data from the largest cohort of infertile women to date, we examined the effects of fertility drugs on thyroid cancer risk. METHODS: A cohort of 54 362 women with infertility problems referred to Danish fertility clinics in the period 1963-1998 was established. A detailed data collection including information about type and amount of treatment was conducted. Using case-cohort techniques, we calculated rate ratios (RRs) of thyroid cancer associated with different fertility drugs after adjustment for age at first live birth. RESULTS: A total of 29 thyroid cancers were identified during follow-up through 2000. Use of clomiphene [RR 5 2.28; 95% confidence interval (CI): 1.08-4.82] or progesterone (RR 5 10.14; 95% CI: 1.93-53.33) was associated with an increased thyroid cancer risk, although the latter estimate was based on few cases. When stratifying for parity status, the risk was primarily associated with clomiphene (RR 5 3.09; 95% CI: 1.21-7.88) in parous women. No significantly increased risk was found after use of gonadotrophins, hCG or GnRH. We observed no association with number of cycles of use or years since first use (latency). CONCLUSIONS: Clomiphene and possibly progesterone may increase thyroid cancer risk, particularly among parous women. Longer follow-up is needed to confirm our findings.

Malignant melanoma risk after exposure to fertility drugs: results from a large Danish cohort study

“…The present infertility cohort has previously been described in detail in papers aimed to investigate the association between use of fertility drugs and risk of breast cancer [29] and thyroid cancer [30]. Briefly, the cohort comprised women with infertility problems referred to all Danish hospitals or private fertility clinics in the period 1963-1998.…”

“…A total of 133 women were diagnosed with malignant melanoma (International Classification of Diseases for Oncology, 7th Revision (ICD-7)) during the follow-up period. For comparison, a subcohort of 1,360 women were randomly selected from the cohort in four strata of age at cohort entry (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), 31-36 and 37-55 years) and in five strata of calendar year of cohort entry (1963-1977, 1978-1984, 1985-1989, 1990-1996, and 1997-1998), equaling 20 strata.…”

Use of Fertility Drugs and Risk of Ovarian Cancer: Danish Population Based Cohort Study

“…The cohort has been described in detail in reports on studies of the association between use of fertility drugs and risks of breast cancer, 28 thyroid cancer, 29 and malignant melanoma. 30 Briefly, the cohort comprised women with infertility referred to all Danish hospitals or private infertility clinics during 1963-98.…”

Nuklearmedizinische Diagnostik, Therapie und Nachsorge des Schilddrüsenkarzinoms

“…Bei der Beurteilung von fokalen Läsionen sind folgende Parameter zu erheben: Größe, Randbegrenzung (scharf/unscharf), Vorliegen eines echoarmen Randsaums (Halozeichen), etwaige Verkalkungen (Mikro-/Makrokalk), Echogenität (echonormal, echoreich, echoarm, echokomplex, echofrei), Größe und Struktur zervikaler Lymphknoten sowie Merkmale der zenLeitthema Tab. 1 Sonographie und Palpation von Schilddrüsenknoten. (Nach [2]) Größe in der Sonographie (mm) Nachweis bei Palpation (%) <5 6 5-10 16 10-15 19 15-20 30 >20 48 tralen und peripheren Durchblutung der Läsion.…”