A Nationwide Cohort Study on the risk of non‐gynecological cancers in women with surgically verified endometriosis

Abstract

We assessed the association of surgically verified endometriosis and risk of non-gynecological cancers according to the type of endometriosis (i.e., ovarian, peritoneal and deep infiltrating endometriosis). All diagnoses of endometriosis combined with relevant procedural codes were identified from the Finnish Hospital Discharge Register 1987-2012. Non-gynecological cancers diagnosed after the endometriosis diagnosis were obtained from the Finnish Cancer Registry. The cohort of 49,933 women with surgically verified endometriosis and the sub-cohorts of ovarian (n = 23,210), peritoneal (n = 20,187), and deep infiltrating (n = 2,372) endometriosis were analyzed separately. The endometriosis cohort contributed 838,685 person-years of follow-up and the Finnish female population served as the reference cohort. The standardized incidence ratio (SIR) and 95% confidence interval (95%CI) was calculated for each cancer separately. The follow-up ended at emigration, death or on the 31st of December 2014. The non-gynecological cancer risk was not increased among women with endometriosis (SIR 1.03, 95%CI 0.98-1.08). Endometriosis was associated with an increased risk of thyroid cancer in the entire cohort (SIR 1.43, 95%CI 1.23-1.64) and in the sub-cohorts of ovarian and peritoneal endometriosis. We found a decreased risk of mouth and pharynx cancer (SIR 0.60, 95%CI 0.41-0.80), and of pancreatic cancer (SIR 0.76, 95%CI 0.58-0.96). The incidence of basal cell carcinoma was elevated in the entire cohort (SIR 1.18, 95%CI 1.10-1.25) and in the sub-cohorts of ovarian and peritoneal endometriosis. In conclusion, women with surgically verified endometriosis have an altered risk of only few non-gynecological cancers.

Systematic Review and Meta-Analysis of Incidence and Prevalence of Endometriosis

“…These studies included women from different age groups, which also may contribute to the identified variations in the estimates. There were two studies utilizing data from hospital discharge databases and one study with self-reported endometriosis, which included women over 60 years (n = 425) and between 55 and 70 years of age (n = 747) and women older than 56 years (n = 471), respectively [11,28,29]. The main symptoms were infertility, peritoneal adhesions, genital pain, and ovarian cyst or growth.…”

“…The main characteristics of the studies included in this review are shown in Table 1. The papers were published between 1989 and 2019 and originated from Norway [10], Denmark [11], the USA [12,16,19,20,25,26,33,35], Australia [13,14], Puerto Rico [15], Sweden [17], Japan [18], the UK [21,22], Israel [23], Germany [24], Iceland [27], Finland [28], Canada [29], Italy [30,32,34,36], and France [31]. The age of participating women varied in different studies from the minimal age of 10 years and older.…”

“…The age of participating women varied in different studies from the minimal age of 10 years and older. The diagnosis of endometriosis was established mostly based on the diagnostic codes of International Classification of Diseases (ICD) [17,[20][21][22][23][24][25][26][27][28][29][30][31][32], self-reported data [10][11][12][13][14][15][16]18,19,35], and by surgery or image tests [33,36] or a combination of self-reported data and image tests [34].…”

Distribution of malignant neoplasms among patients with endometriosis: an epidemiological study

“…Среди других онкологических заболеваний наиболее часто связывают с эндометриозом неходжкинскую лимфому [6, 10, 11] и меланому кожи [6,10,11,29]. В небольших исследованиях также сообщалось, что женщины с эндометриозом подвергаются повышенному риску развития злокачественных опухолей органов эндокринной системы [11], головного мозга [11], рака щитовидной железы и почки [11,30], базальноклеточного рака [11,30].…”

Endometriosis and an increased risk of malignancies

“…Liisu Saavalainen et al found an increased risk of thyroid cancer in the entire cohort and in the sub-cohorts of ovarian and peritoneal endometriosis. That was especially seen for thyroid cancer with papillary histology [34].…”