Epidemiology of breast cancer in Cyprus: Data on newly diagnosed cases and survival rates

This article presents analyzed data on new diagnoses and mortality of breast cancer, between 2005 and 2013, in the Republic of Cyprus. New diagnoses are presented by demographic and clinical/histological variables that include cancer grade, behaviour, stage, and histological type at diagnosis (always as a primary site). Breast cancer-related deaths are presented by gender. Net survival rates based on cohort and period methods are presented by age group, cancer grade, behaviour, and stage at diagnosis, for all cases and for cases of Greek-Cypriot ethnicity. The unprocessed data of the Cyprus Cancer Registry were provided by the Health Monitoring Unit of the Ministry of Health of the Republic of Cyprus.

The data can be included in analyses to better understand the epidemiology of breast cancer. The data can be used for developing policies related to breast cancer prevention.

Data
This article includes analyzed data on breast cancer cases obtained from the Cyprus Cancer Registry in the Health Monitoring Unit of the Ministry of Health of the Republic of Cyprus for the period 2005-2013. Demographic and clinical/histological parameters of newly diagnosed breast cancer cases are shown in Tables 1-5. Table 6 presents the classification of histological types and their subtypes (always as primary sites) used for the analysis of data. Breast cancer mortality per year can be found in Table 7. Net survival rates for breast cancer (Tables 8-15) are presented for 2004-2008 and  2009-2013.  Table 1 shows counts and percentages of newly diagnosed breast cancer cases by gender, age, ethnicity (Greek-Cypriot/Non-Greek-Cypriot/Unknown), marital status at the time of diagnosis (single/married/divorced or separated/widowed/unknown), smoking history at the time of diagnosis (yes/no/unknown), and patients' birthplace (Cyprus districts) as well as the median and the interquartile range (IQR) of patients' age. Tables 2-5 present counts and percentages of newly diagnosed breast cancer cases by cancer grade (well differentiated/moderately differentiated/poorly differentiated/undifferentiated/ unknown), behaviour (in situ/invasive), stage (distant metastatic/in situ/ locoregional invasive/unknown), and histological type at diagnosis (adenoid cystic carcinoma/carcinoma with apocrine features/carcinoma with medullary features/cribriform carcinoma/inflammatory carcinoma/invasive carcinoma of no special type/invasive lobular carcinoma/mesenchymal tumours/ metaplastic carcinoma/mucinous carcinoma/Paget's disease/phyllodes tumour/rare variants/tubular carcinoma). Cases are also presented by ethnicity (Greek-Cypriot and Non-Greek-Cypriot). Armenians and Maronites belong to the Greek-Cypriot community but represent different ethnic/religious groups and given their small numbers were included along with the European Union (EU) foreigners and the non-EU foreigners in the non-Greek-Cypriot group. The ethnicity group "Unknown" is omitted. Subtypes of breast cancer classified in the categories of histological type used in the analysis are presented in Table 6. Table 7 gives breast cancer-related deaths by gender. Tables 8-15 show five-year net survival rates of breast cancer cases, based on cohort and period approaches, for 2004-2008 and 2009-2013, by age group, cancer stage, grade, and behaviour at diagnosis for all recorded cases (Tables 8-11) and for Greek-Cypriots only (Tables 12-15).

Experimental design, materials and methods
The data presented in this article were obtained from the Cyprus Cancer Registry and the Causes of Death Registry in the Health Monitoring Unit at the Ministry of Health of the Republic of Cyprus. The Carcinoma with medullary features Carcinoma with medullary features      Table 8 Five-year net survival rates of all breast cancer cases by age group.

Table 9
Five-year net survival rates of all breast cancer cases by different cancer grade at diagnosis. Counts and percentages of 4700 newly diagnosed breast cancer cases of known ethnicity are presented by cancer grade (Table 2), behaviour (Table 3), stage (Table 4), and histological type at diagnosis (Table 5). Table 6 shows breast cancer histological categories and their subtypes, which have been presented previously in Table 5, and the respective International Classification of Diseases for Oncology (ICD-O-3) morphological code adopted by the International Agency for Research on Cancer (IARC), World Health Organization (WHO) [2]. Table 7 shows breast cancer-related deaths by gender and the number of deaths attributable to breast cancer out of 1000 deaths among women and men, and in both sexes. Information on annual numbers of deaths in Cyprus were obtained from the report on mortality statistics between 2004 and 2014 [3].
Tables 8-15 present 5-year net survival rates for 2004-2008 and 2009-2013. Net survival rates are presented by age group (Table 8), cancer grade (Table 9), behaviour (Table 10), and stage at diagnosis (Table 11). The survival analysis included cases meeting the following criteria: (a) they were followedup after their diagnosis and (b) their age was known at the time of diagnosis. The most recent entry with an updated cancer status was considered for patients recorded more than once in the registry.
Five-year net survival rates were estimated using two different approaches: cohort-based and period [4,5]. The cohort-based survival analysis involves cases diagnosed in 2004-2008 and their survival has been assessed in the 5 years (2009-2013) following the date of diagnosis. The period approach involves cases diagnosed over the period 2004-2013 but considers their survival experience in recent years i.e. over the period 2009-2013. Therefore, the period method provides more up-to-date estimates and quite closely predicts survival rates that will later be observed for cases diagnosed in 2009-2013. Net survival was estimated using the stns command in STATA version 14 [6]. Survival Table 10 Five-year net survival rates of all breast cancer cases by cancer behaviour at diagnosis.     analyses were performed for all cases (Tables 8-11) and for cases of Greek-Cypriot ethnicity (Tables 12-15). Background mortality data used for net survival assessment were in the format of agespecific daily death rate for Cyprus and were retrieved by WHO [7]. All data were analyzed using STATA version 14 (StataCorp LP, College Station, Texas, USA).

Acknowledgement
The data used in this study were provided by the Health Monitoring Unit of the Ministry of Health of the Republic of Cyprus. The ideas and opinions expressed herein are those of the authors. Endorsement of these ideas and opinions by the Ministry of Health of the Republic of Cyprus is not intended nor should it be inferred.

Transparency document. Supporting information
Transparency data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.dib.2018.05.042.

Table 14
Five-year net survival rates of Greek-Cypriot breast cancer cases by cancer behaviour at diagnosis.

Table 15
Five-year net survival rates of Greek-Cypriot breast cancer cases by cancer stage at diagnosis.