Screening interval and risk of invasive squamous cell cervical cancer

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 101; no. 1; pp. 29 - 37
• Main Authors: Miller, Marie Grisham, Sung, Hai-Yen, Sawaya, George F, Kearney, Kathleen A, Kinney, Walter, Hiatt, Robert A
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 2003; The American College of Obstetricians and Gynecologists; Elsevier Science
• Subjects: Adult; Biological and medical sciences; Carcinoma, Squamous Cell - diagnosis; Case-Control Studies; Female; Female genital diseases; Gynecology. Andrology. Obstetrics; Humans; Mass Screening - statistics & numerical data; Medical sciences; Middle Aged; Odds Ratio; Predictive Value of Tests; Time Factors; Tumors; Uterine Cervical Neoplasms - diagnosis; Vaginal Smears - statistics & numerical data; Human; Cell proliferation; Squamous cell carcinoma; Clinical stage; Female; Malignant tumor; Uterine cervix; Case control study; Risk analysis; Medical screening; Uterine cervix diseases; Female genital diseases
• ISSN: 0029-7844; 1873-233X
• DOI: 10.1016/S0029-7844(02)02454-7

To compare the risks of developing invasive squamous cell cervical cancer associated with screening intervals of 1, 2, and 3 years after a negative cervical smear. We conducted a matched case-control study of invasive squamous cell cervical cancer patients ( n = 482) diagnosed between 1983 and 1995 among long-term members of a large health maintenance organization. Controls were matched for age, length of membership, and race ( n = 934). Screening interval was time between the last negative cervical smear and the case diagnosis date. The main outcome measure was the relative odds of invasive disease associated with 1-year, 2-year, and 3-year intervals. The odds ratio for a 2-year versus a 1-year interval was 1.72 (95% confidence interval 1.12, 2.64, P = .013) and for a 3-year versus a 1-year interval was 2.06 (95% confidence interval 1.21, 3.50, P = .007). The odds ratio for a 3-year versus a 2-year interval was 1.20 (95% confidence interval 0.65, 2.21, P = .561). Controlling for ever having had an abnormal cervical smear or a previous consecutive negative smear did not substantially change these results. In this large health plan, the relative risks of invasive squamous cell cervical cancer were significantly greater for 2-year and 3-year cervical cancer screening intervals compared with a 1-year interval, but not for a 3-year interval compared with a 2-year interval. Our findings need to be placed in the context of the low absolute risks of developing invasive cervical cancer during the first 3 years after a negative cervical smear before making policy recommendation.