The influence of menopausal hormone therapy on tumour characteristics and survival in endometrial cancer patients.
BACKGROUND
Menopausal hormone therapy (MHT) is a well-established factor in endometrial carcinogenesis, and therefore, could have prognostic implications. We investigated the effects of ever use of MHT on tumour grade and depth of myometrial invasion and 5-year relative survival in postmenopausal endometrial cancer patients.


METHODS
We used a nationwide, population-based case-case design, of 683 Swedish women aged 50-74 years diagnosed with endometrial cancer during 1994 to 1995, followed up to 5 years after diagnosis. We applied polytomous multiple logistic regression to investigate the associations between the use of MHT and tumour grade, and myometrial invasion and Poisson regression for modelling 5-year excess mortality.


RESULTS
Compared to never use, ever use of any MHT entailed lower risks of having moderately and poorly differentiated tumours. The lowest odds ratios for poorly differentiated tumours were seen for ever users of cyclically combined oestrogen-progestin [OR=0.23 (95% CI=0.07-0.73)]. Ever users of any form of MHT; particularly, medium potency MHT users, had significantly lower risks for tumours with deep myometrial invasion. Adjusted estimated relative excess hazard ratios revealed significantly improved survival for ever users of any form of MHT [RER=0.40 (95% CI=0.16-0.97)]; in particular ever users of any form of oestrogens [RER=0.38 (95% CI=0.15-0.99)].


CONCLUSIONS
Endometrial cancer patients who were ever users of MHT had more favourable tumour characteristics and better survival compared to never users of MHT. These findings support the notion that MHT induces endometrial cancer with less aggressive characteristics.
Orgéas
Chantal C
CC
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, PO Box 281, SE-17177 Stockholm, Sweden. cco4@le.ac.uk
Hall
Per
P
Wedrén
Sara
S
Dickman
Paul W
PW
Czene
Kamila
K
D000230:Adenocarcinoma / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D000367:Age Factors; D000368:Aged; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000473:pathology; D004812:Epidemiologic Methods; D045166:Estradiol Congeners / Q000009:adverse effects; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009215:Myometrium / Q000473:pathology; D009361:Neoplasm Invasiveness; D017698:Postmenopause; D045167:Progesterone Congeners / Q000009:adverse effects; D011379:Prognosis; D013548:Sweden / Q000453:epidemiology
D045166:Estradiol Congeners; D045167:Progesterone Congeners