Pregnancy history and incidence of melanoma in women: a pooled analysis.
There is evidence that pregnancy history including age at first birth and parity may play a role in risk of cutaneous melanoma in women, although, epidemiological findings are inconsistent. We conducted a collaborative analysis of these factors using the original data from ten completed case-control studies (2391 cases and 3199 controls), and assessed the potential confounding effects of socioeconomic, pigmentary, and sun exposure-related factors. We found no overall association with ever having a live birth (pooled odds ratio (pOR) 0.95, 95% confidence interval (CI) 0.67-1.35). However, we detected a reduced risk of melanoma among women with higher parity (> or = 5 versus no live births pOR 0.76, 95% CI 0.49-1.18, each live birth pOR 0.95, 95% CI 0.91-0.99, p trend = 0.05). Women with both earlier age at first birth (e.g., <20 years) and higher parity (e.g., > or = 5 live births) had a particularly lower risk than women with later age at first birth (e.g., > or = 25 years) and lower parity (e.g., <5 live births) (pOR 0.33, 95% CI 0.14-0.75). The results are compatible with an effect of reproductive history-related factors on melanoma risk, but also could reflect differences in other factors, such as sun exposure history.
Karagas
Margaret R
MR
Section of Biostatistics and Epidemiology, Department of Community and Family Medicine, Dartmouth Medical School, 7927 Rubin Bldg., One Medical Center Drive, Hanover, Lebanon, New Hampshire, 03756-0001, USA. margaret.karagas@dartmouth.edu
Zens
Michael S
MS
Stukel
Therese A
TA
Swerdlow
Anthony J
AJ
Rosso
Stefano
S
Osterlind
Anne
A
Mack
Thomas
T
Kirkpatrick
Connie
C
Holly
Elizabeth A
EA
Green
Adele
A
Gallagher
Richard
R
Elwood
J Mark
JM
Armstrong
Bruce K
BK
D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008423:Maternal Age; D008545:Melanoma / Q000453:epidemiology*; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D017584:Reproductive History; D012307:Risk Factors; D012878:Skin Neoplasms / Q000453:epidemiology*; D012880:Skin Pigmentation