Smoking and Overweight: Negative Prognostic Factors in Stage III Epithelial Ovarian Cancer

Abstract

Objective: Smoking and overweight are associated with poorer prognosis in several cancer types. The prognostic effect of smoking and body mass index (BMI) on ovarian cancer is unknown. Methods: Ovarian cancer cases were from the Danish MALOVA (MALignant OVArian cancer) study. Information on smoking status and BMI was obtained from a personal interview conducted closely after primary surgery. Cox regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) for ovarian cancer -specific death in relation to smoking variables and BMI. Results: A total of 295 women with stage III epithelial ovarian cancer were identified and followed to death or for a median of 7.3 years (range, 5.4-9.5 years). Median survival time for normal-weight never smokers was 2.8 years (95% CI, 2.3-3.2) compared with 1.2 years (95% CI, 0.8-2.3) for overweight current smokers. Current smokers had a significantly increased risk of ovarian cancer death compared with never smokers in multivariate Cox analysis (HR, 1.65; 95% CI, 1.22-2.24). The negative effect of smoking diminished with increasing time since a former smoker had stopped smoking (HR, 0.89; 95% CI, 0.80-0.98 per 5 years since stop of smoking). Overweight women also had an increased risk of ovarian cancer death (HR, 1.83; 95% CI, 1.38-2.42) compared with normal-weight women. Conclusion: Smoking at the time of diagnosis and premorbid overweight were negative prognostic factors for ovarian cancer -specific survival. The negative effect of smoking decreased with increasing time since stop of smoking. (Cancer Epidemiol Biomarkers Prev 2006; 15(4):798 -803)

Cigarette Smoking and Survival after Ovarian Cancer Diagnosis

“…The P for linear trend was calculated by the change in the likelihood ratio statistic for entry of a linear term for the continuous variable in the model and thus was a m 2 test on 1 degree of freedom. All analyses were adjusted for known prognostic factors, age at diagnosis, International Federation of Gynecology and Obstetrics (FIGO) stage, and grade (15), in addition to histologic subtype, amount of residual disease, treatment with platinum-based chemotherapy, and body mass index (BMI) to allow for direct comparison with the results of Kjaerbye-Thygesen et al (12). We also considered aspects of diet (vegetables and vitamin E intake, alcohol and caffeine consumption, and total kilocalories) and relevant etiologic factors (duration of oral contraceptive use, parity, history of tubal ligation, and hysterectomy) as potential confounders but did not include them in the final models as they did not alter the effect estimates.…”

“…Because cancers in never smokers arise without any growth-promoting effects of carcinogens in cigarette smoke, the mechanisms of carcinogenesis in smokers and never smokers may be distinct and could lead to differences in tumor biology, natural history, and, possibly, survival. Little is known about the influence of smoking on ovarian cancer survival, but a recent article by KjaerbyeThygesen et al (12) has suggested that smoking may be detrimental for ovarian cancer survival. Among 295 women diagnosed with stage III invasive epithelial ovarian cancer, this group found a statistically significant increased risk of death among current smokers [hazard ratio (HR), 1.65; 95% confidence interval (95% CI), 1.22-2.24] and that this negative effect of smoking diminished with longer times since quitting (HR, 0.89; 95% CI, 0.80-0.98 per 5 years since cessation of smoking; ref.…”

“…Among 295 women diagnosed with stage III invasive epithelial ovarian cancer, this group found a statistically significant increased risk of death among current smokers [hazard ratio (HR), 1.65; 95% confidence interval (95% CI), 1.22-2.24] and that this negative effect of smoking diminished with longer times since quitting (HR, 0.89; 95% CI, 0.80-0.98 per 5 years since cessation of smoking; ref. 12). The only other study of which we are aware did not have the statistical power to examine the association between smoking and survival because too few cases were ever smokers (13).…”

Obesity and Ovarian Cancer Survival: A Systematic Review and Meta-analysis

“…Five studies used data on height and weight obtained 1 year before diagnosis (26) or from reports of women's usual adult weight (27)(28)(29)(30), 4 studies measured BMI at the time of diagnosis (10, 13, 14, 31), 8 at the commencement of chemotherapy (9,11,15,20,24,25,32,33), 1 study did not state when BMI was measured (34), and 2 studies assessed BMI at multiple time points (12,35) including 5 years before diagnosis (12,35 (13,24,26,27,34) whereas others used variations including all women with a BMI < 20 or BMI < 25. Median follow-up time varied considerably between studies ranging from less than 1 year to greater than 10 years.…”

A Rapid Outcomes Ascertainment System Improves the Quality of Prognostic and Pharmacogenetic Outcomes from Observational Studies

“…The number of molecular prognostic and pharmacogenetic outcomes studies derived from case-control studies is increasing, as many case-control studies now collect biological samples (6,9,(17)(18)(19). The present study evaluated the quality of molecular prognostic and pharmacogenetic outcomes obtainable from an observational (case-control) study.…”