Jean‐Luc Bulliard

BACKGROUND: The increase in incidence of thyroid cancer during the last decades without concomitant rise in mortality may reflect the growing detection of indolent forms of thyroid cancer, and may have fueled unnecessary thyroidectomies. Our aim was therefore, to compare recent secular trends in surgical intervention rate for thyroid cancer with the incidence and mortality of thyroid cancer to assess overdiagnosis and resulting overtreatment. METHODS: We conducted a population-based temporal trend study in Switzerland from 1998 to 2012. All cases of invasive thyroid cancer, deaths from thyroid cancer, and cancer-related thyroidectomies were analyzed. We calculated changes in age-standardized thyroid cancer incidence rates, stratified by histologic subtype and tumor stage, thyroid cancer-specific mortality, and thyroidectomy rates. RESULTS: Between 1998 and 2012, the age-standardized annual incidence of thyroid cancer increased from 5.9 to 11.7 cases/100,000 among women (annual mean absolute increase: +0.43/100,000/year) and from 2.7 to 3.9 cases/100,000 among men (+0.11/100,000/year). The increase was limited to the papillary subtype, the most indolent form of thyroid cancer. The incidence of early stages increased sharply, the incidence of advanced stages increased marginally, and the mortality from thyroid cancer decreased slightly. There was a three- to four-fold increase in the age-standardized annual thyroidectomy rate in both sexes. CONCLUSIONS: We observed a large increase in the incidence of thyroid cancer, limited to papillary and early stage tumors, with a three- to four-fold parallel increase in thyroidectomy. The mortality slightly decreased. These findings suggest that a substantial and growing part of the detected thyroid cancers are overdiagnosed and overtreated. IMPACT: Targeted screening and diagnostic strategies are warranted to avoid overdetection and unnecessary treatment of thyroid cancers.

OBJECTIVE: Participation, an indicator of screening programme acceptance and effectiveness, varies widely in clinical trials and population-based colorectal cancer (CRC) screening programmes. We aimed to assess whether CRC screening participation rates can be compared across organized guaiac fecal occult blood test (G-FOBT)/fecal immunochemical test (FIT)-based programmes, and what factors influence these rates. METHODS: Programme representatives from countries participating in the International Cancer Screening Network were surveyed to describe their G-FOBT/FIT-based CRC screening programmes, how screening participation is defined and measured, and to provide participation data for their most recent completed screening round. RESULTS: Information was obtained from 15 programmes in 12 countries. Programmes varied in size, reach, maturity, target age groups, exclusions, type of test kit, method of providing test kits and use, and frequency of reminders. Coverage by invitation ranged from 30-100%, coverage by the screening programme from 7-67.7%, overall uptake/participation rate from 7-67.7%, and first invitation participation from 7-64.3%. Participation rates generally increased with age and were higher among women than men and for subsequent compared with first invitation participation. CONCLUSION: Comparisons among CRC screening programmes should be made cautiously, given differences in organization, target populations, and interpretation of indicators. More meaningful comparisons are possible if rates are calculated across a uniform age range, by gender, and separately for people invited for the first time vs. previously.

BACKGROUND: CONCORD-3 highlighted wide disparities in population-based 5-year net survival for cutaneous melanoma during 2000-2014. Clinical evidence suggests marked international differences in the proportion of lethal acral and nodular subtypes of cutaneous melanoma. OBJECTIVES: We aimed to assess whether the differences in morphology may explain global variation in survival. METHODS: Patients with melanoma were grouped into the following seven morphological categories: malignant melanoma, not otherwise specified (International Classification of Diseases for Oncology, third revision morphology code 8720), superficial spreading melanoma (8743), lentigo maligna melanoma (8742), nodular melanoma (8721), acral lentiginous melanoma (8744), desmoplastic melanoma (8745) and other morphologies (8722-8723, 8726-8727, 8730, 8740-8741, 8746, 8761, 8770-8774, 8780). We estimated net survival using the nonparametric Pohar Perme estimator, correcting for background mortality by single year of age, sex and calendar year in each country or region. All-ages survival estimates were standardized using the International Cancer Survival Standard weights. We fitted a flexible parametric model to estimate the effect of morphology on the hazard of death. RESULTS: Worldwide, the proportion of nodular melanoma ranged between 7% and 13%. Acral lentiginous melanoma accounted for less than 2% of all registrations but was more common in Asia (6%) and Central and South America (7%). Overall, 36% of tumours were classified as superficial spreading melanoma. During 2010-2014, age-standardized 5-year net survival for superficial spreading melanoma was 95% or higher in Oceania, North America and most European countries, but was only 71% in Taiwan. Survival for acral lentiginous melanoma ranged between 66% and 95%. Nodular melanoma had the poorest prognosis in all countries. The multivariable analysis of data from registries with complete information on stage and morphology found that sex, age and stage at diagnosis only partially explain the higher risk of death for nodular and acral lentiginous subtypes. CONCLUSIONS: This study provides the broadest picture of distribution and population-based survival trends for the main morphological subtypes of cutaneous melanoma in 59 countries. The poorer prognosis for nodular and acral lentiginous melanomas, more frequent in Asia and Latin America, suggests the need for health policies aimed at specific populations to improve awareness, early diagnosis and access to treatment. What is already known about this topic? The histopathological features of cutaneous melanoma vary markedly worldwide. The proportion of melanomas with the more aggressive acral lentiginous or nodular histological subtypes is higher in populations with predominantly dark skin than in populations with predominantly fair skin. What does this study add? We aimed to assess the extent to which these differences in morphology may explain international variation in survival when all histological subtypes are combined. This study provides, for the first time, international comparisons of population-based survival at 5 years for the main histological subtypes of melanoma for over 1.5 million adults diagnosed during 2000-2014. This study highlights the less favourable distribution of histological subtypes in Asia and Central and South America, and the poorer prognosis for nodular and acral lentiginous melanomas. We found that later stage at diagnosis does not fully explain the higher excess risk of death for nodular and acral lentiginous melanoma compared with superficial spreading melanoma.

The site-specific relationship between melanoma and sun exposure was investigated in the high-risk region of New Zealand. Age and latitude of residence were used as biological and geographical proxy measures of exposure for the 16,117 newly incident cases and 3,150 death records reported between 1968 and 1993. Age-standardized rates were the highest for the trunk in males and for the lower limbs in females, but once body surface area was accounted for, highest rates were found on fully exposed sites, particularly the ears in men. Melanomas occurred at a substantially younger age on intermittently exposed sites than chronically exposed ones (difference of about 13 and 27 years for men and women, respectively, between the trunk and the face). Age and latitude were found to influence melanoma rates in a sex- and site-specific fashion. For heavily exposed body areas, incidence rates increased more modestly with age before age 50 than after. In contrast, sharp increases in risk occurred from early age for episodically exposed sites with a reversal of trend observed among the elderly. For males, the magnitude of the latitude gradient was about 65% (incidence) and 50% (mortality) greater for body areas most intermittently exposed compared with those with a least intermittent pattern of exposure. The latitude gradient was steeper for males than females and for incidence than mortality, regardless of the pattern of site exposure. Sex- and age-specific differences in risk were largely explained by the varying patterns of exposure. These results confirm that intermittent exposure is probably more effective than continuous exposure in producing an early onset of melanoma. Reducing the episodes of acute exposure remains a paramount aspect to melanoma prevention strategies.

BACKGROUND: Euromelanoma is a skin cancer education and prevention campaign that started in 1999 in Belgium as 'Melanoma day'. Since 2000, it is active in a large and growing number of European countries under the name Euromelanoma. OBJECTIVE: To evaluate results of Euromelanoma in 2009 and 2010 in 20 countries, describing characteristics of screenees, rates of clinically suspicious lesions for skin cancer and detection rates of melanomas. METHODS: Euromelanoma questionnaires were used by 20 countries providing their data in a standardized database (Belgium, Croatia, Cyprus, Czech Republic, FYRO Macedonia, Germany, Greece, Hungary, Italy, Lithuania, Luxembourg, Malta, Moldavia, Portugal, Serbia, Slovenia, Spain, Sweden, Switzerland and Ukraine). RESULTS: In total, 59,858 subjects were screened in 20 countries. Most screenees were female (64%), median ages were 43 (female) and 46 (male) and 33% had phototype I or II. The suspicion rates ranged from 1.1% to 19.4% for melanoma (average 2.8%), from 0.0% to 10.7% for basal cell carcinoma (average 3.1%) and from 0.0% to 1.8% for squamous cell carcinoma (average 0.4%). The overall positive predictive value of countries where (estimation of) positive predictive value could be determined was 13.0%, melanoma detection rates varied from 0.1% to 1.9%. Dermoscopy was used in 78% of examinations with clinically suspected melanoma; full body skin examination was performed in 72% of the screenees. CONCLUSION: Although the population screened during Euromelanoma was relatively young, high rates of clinically suspected melanoma were found. The efficacy of Euromelanoma could be improved by targeting high-risk populations and by better use of dermoscopy and full body skin examination.