Monthly injectable contraceptives and the risk of all cancers combined and site-specific cancers in Shanghai.
OBJECTIVE
The risk of 12 types of cancer in relation to use of monthly injectable contraceptives was assessed in a prospective study in Shanghai, China.


METHODS
From 1989 to 1991, an in-person interview was administered to 267,400 female textile workers to ascertain information on risk factors for breast cancer, contraceptive use and induced abortions. The cohort was followed until July 2000 for incident cancer cases. Cox proportional hazards analysis was used to calculate incidence rate ratios for specific types of cancer in women who ever had used monthly injectable contraceptives and by length of use.


RESULTS
There was a reduced risk of uterine corpus cancer for women who had ever used monthly injectable contraceptives. No association was observed between the use of monthly injectable contraceptives and the risk of all cancers combined and for any of the 11 other cancers considered.


CONCLUSIONS
There appears to be no evidence of an increased risk of cancer after exposure to monthly injectable contraceptives in our study.
Rosenblatt
Karin A
KA
Department of Kinesiology and Community Health, University of Illinois at Urbana Champaign, Champaign, IL 61820, USA. krosenbl@uiuc.edu
Gao
Dao L
DL
Ray
Roberta M
RM
Nelson
Zakia C
ZC
Wernli
Karen J
KJ
Li
Wenjin
W
Thomas
David B
DB
D002681:China / Q000453:epidemiology; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects*; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D007267:Injections; D009369:Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D011446:Prospective Studies
D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations