Does an epidemiological comparison support a common cellular lineage for similar subtypes of postmenopausal uterine and ovarian carcinoma? The Norwegian Women and Cancer Study

• Published in: International journal of cancer 2017-09, Vol.141 (6), p.1181-1189
• Main Authors: Jareid, Mie, Licaj, Idlir, Standahl Olsen, Karina, Lund, Eiliv, Bøvelstad, Hege M.
• Format: Article
• Language: English
• Subjects: Body mass; Body mass index; Cancer; Cohort Studies; etiology; Female; Health risk assessment; Heterogeneity; histological subtypes; Humans; Inventories; Life span; Medical research; Menstruation; Middle Aged; Multivariate Analysis; Norway - epidemiology; Ovarian cancer; Ovarian carcinoma; ovarian neoplasms; Ovarian Neoplasms - epidemiology; Ovarian Neoplasms - pathology; Parity; Post-menopause; Postmenopause; Proportional Hazards Models; prospective cohort study; Regression analysis; Risk factors; Smoking; Studies; Tumors; Uterine cancer; uterine neoplasms; Uterine Neoplasms - epidemiology; Uterine Neoplasms - pathology; Uterus
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.30826

Uterine and ovarian carcinomas have the same major histological subtypes, but whether they originate from the same cell types is a matter of ongoing debate. Uterine and ovarian endometrioid and clear cell carcinoma (ECC) and uterine and ovarian serous carcinoma (SC) may originate in the same location, or share a common lineage of differentiation. Epidemiologically, a common cellular lineage should be reflected in similar risk associations, and we explored the similarity of uterine and ovarian ECC and uterine and ovarian SC. We included 146,316 postmenopausal participants from the Norwegian Women and Cancer Study. Exposure information was taken from self‐administered questionnaires, and cancer cases were identified through linkage to the Cancer Registry of Norway. Hazard ratios with 95% confidence intervals for uterine and ovarian carcinoma and their subtypes were calculated using multivariable Cox regression models, and a Wald test was used to check for heterogeneity. During 1.6 million person‐years, 1,006 uterine and 601 ovarian carcinomas were identified. Parity, total menstrual lifespan, body mass index and smoking were differentially associated with total uterine and total ovarian carcinoma (pheterogeneity = 0.041, 0.027,  0.05). Smoking was differentially associated with uterine and ovarian SC (pheterogeneity = 0.021). Our epidemiological analyses do not contradict a common differentiation lineage for uterine and ovarian ECC. Uterine and ovarian SC are less likely to be of a common lineage of differentiation, based on their difference in risk associated with smoking. What's new? Do uterine and ovarian cancers share a common lineage? Depends on the type, new results suggest. To investigate the cancers' cellular origins, these authors compared risk factors between uterine and ovarian endometrioid and clear cell tumors (ECC) and between uterine and ovarian serous carcinoma (SC). If the cancers originate in the same cell types, the authors reasoned, risk factors should pose the same danger for both locales. After evaluating various risk factors, including smoking, parity and obesity, they concluded that uterine and ovarian ECC appear to share a common lineage. However, smoking affects the risk of uterine and ovarian SC differently, suggesting they may arise separately.