Characteristics and survival associated with ovarian cancer diagnosed as first cancer and ovarian cancer diagnosed subsequent to a previous cancer

Abstract

Objective:
To examine the risk of subsequent primary ovarian cancer among women diagnosed previously with cancer (subsequent cohort) and to compare demographic and tumor characteristics affecting overall survival of these women and women diagnosed with first primary ovarian cancer (index cohort).


Methods: 
We identified the two cohorts of women using the 1973-2005 Surveillance, Epidemiology and End Results (SEER) result data. We calculated relative risk of subsequent primary ovarian cancer and estimated 5-year risks of dying (hazard-ratios) after diagnosis of the first or subsequent primary ovarian cancer in the two cohorts, respectively using Cox modeling.


Results:
Women diagnosed with index cancers of the corpus uteri, colon, cervix, and melanoma at age younger than 50 had increased risk of ovarian cancer within 5 years after diagnosis (p<0.05); young breast cancer survivors had continued risk beyond 20 years. In 5-year follow-up survival analysis, the factors associated with a better survival (p<0.05) were similar in both cohorts and included more recent diagnosis; localized or regional disease; age <50 years at diagnosis; and being white versus black. A lower risk of dying from mucinous, endometrioid, or non-epithelial tumors than from serous was seen after 15 months (p<0.01), or after 32 months from diagnosis of the index and subsequent cohorts, respectively. (clear cell??)


Conclusions:
Age, stage, and histology affect ovarian cancer survival. The increased risk of ovarian cancer over time, especially among breast and colon cancer survivors who are less than 50 years of age, suggests common etiologies and necessitates careful surveillance by health care providers and increased survivors awareness through educational efforts.