Two reproductive factors linked to ovarian cancer survival

Age at menarche and number of lifetime ovulations may affect prognosis after diagnosis of ovarian cancer.

Findings from previous studies have shown an association between certain reproductive factors and improved ovarian cancer risk; however, associations between reproductive factors and ovarian cancer survival are lacking.

Therefore, researchers conducted a longitudinal study to assess the influence of reproductive factors on ovarian cancer survival after diagnosis. They analyzed data from 410 women aged 20 to 54 from the 1980-1982 Cancer and Steroid Hormone (CASH) study. The data were linked with data from the SEER Program.

Two-hundred twelve women died during a median follow-up of 9.2 years; 79.7% of deaths were due to ovarian cancer, according to researchers. The overall survival rate was 48% at 15 years.

In an unadjusted analysis, poorer survival was observed among women with more lifetime ovulatory cycles (P<.05). Poorer survival rates were also observed in multivariate analysis among women with more lifetime ovulatory cycles vs. women with less (HR=1.67; 95% CI, 1.20-2.33). Furthermore, 15-year survival was better among women with the lowest number of lifetime ovulations vs. that of women with the highest (56.7% vs. 33.3%).

Additionally, women aged younger than 12 at menarche had worse survival rates than women aged 14 or older at menarche (HR=1.51; 95% CI, 1.02-2.24). – by Christen Haigh

Robbins CL. Cancer Epidemiol Biomarkers Prev. 2009;18:2035-2041.

This study identifies a novel finding. We knew that risk of ovarian cancer is influenced by the number of lifetime ovulatory cycles and age at menarche, but this is the first study to identify the role of these factors in determining mortality.

The findings generate questions rather than offer treatment guidelines. For example, if an increased number of ovulatory cycles lead to not only cancer but also death from cancer, why is that? It may be that there is something different about these cancers — does the increased ovulation damage a specific pathway, thereby leading to the development of ovarian cancer? In the article, the authors mention p53 mutation as a possibility for what sets these kinds of cancers apart from cancers not influenced by ovulatory cycles. This is a good jumping off point for investigating the difference between these cell types, finding the abnormality and targeting it to prevent cancer.

Another area for further investigation is examining these findings in an older population. Women in this study were aged 20-54 years. The majority of women with ovarian cancer are aged older than 50 years, and over half are aged older than 60 years. So, these findings may not be generalized to everybody who has ovarian cancer. It would be interesting to see if these findings hold true in an older population.

Additionally, borderline tumors tend to occur in younger women. And it is not clear if this study included women with borderline tumors or not, but it would be something interesting to examine in the future.

Finally, these findings may further highlight the role of oral contraceptives in limiting the number of ovulatory cycles. We have always discussed oral contraceptives as a risk-reducing strategy, but now they may even correlate with mortality reduction.

– Jubilee Brown, MD

Assistant professor, The University of Texas M. D. Anderson Cancer Center, Houston