Venous thromboembolism in ovarian cancer
Introduction
Most women with ovarian cancer present with advanced disease and undergo complicated treatment regimens, including one or more major surgeries and several courses of chemotherapy. During this extended treatment course, many women suffer a variety of complications, including venous thromboembolism (VTE, deep vein thrombosis or pulmonary embolism). In a recent retrospective study of 253 women with epithelial ovarian cancer who underwent both surgery and chemotherapy and who were followed for a median of 2.6 years, the reported incidence of VTE was 16.6%, 15% with deep vein thrombosis (DVT) and 1.6% with pulmonary embolism (PE) [1]. The risk factors for VTE depended on the length of time between the cancer diagnosis and the VTE diagnosis. Early VTE events were associated with surgery and chemotherapy, whereas later VTE events were associated with older age, prior history of DVT, FIGO stage IIC–IV, and presence of residual tumor after initial surgery [1]. In a recent study, the incidence of VTE in 12 common cancers in California was evaluated. This population-based study reported that among 5347 patients with advanced ovarian cancer, the 2-year incidence of VTE was 3.3%, with a 2-year survival of 50% [2]. This trial did not analyze in detail the differences in incidence and outcome specific to the ovarian cancer population based on histology, comorbidities, or type of surgery. In the present study, our aims were to define the incidence and time-course of VTE in a large population based cohort of women with ovarian cancer, to analyze the strength of potential risk factors associated with the occurrence of VTE, and to determine the effect of VTE on overall survival.
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Materials and methods
Ovarian cancer cases were identified using the comprehensive California Cancer Registry, which identifies 99% of all cancers diagnosed in California [3]. Venous thromboembolic events were determined by linking the registry cases to the California Patient Discharge Data Set using patient-specific identifiers. The California Patient Discharge Data Set contains serial linked medical–diagnostic and procedural data from July 1990 to the present for all patients admitted to hospitals in California [4]
Results
Over the 6-year period, there were 13,031 cases of ovarian cancer in the cancer registry that could be linked to the discharge database. Table 2 outlines the demographic characteristics of this cohort including mean age, race, stage, histologic type, and the total number of patients with episodes of VTE. Overall, the 24-month cumulative incidence of VTE was 672 (5.2%), 1.4% with PE and 3.7% with DVT. 30% of the VTE events occurred within 3 months of major pelvic or abdominal cancer surgery, 5%
Discussion
Prior studies that have analyzed VTE in women with ovarian cancer have had significant methodological limitations. Levitan et al. who analyzed only medicare patients with cancer who required hospitalization reported that the highest incidence of VTE was in women with ovarian cancer [8]. Other studies have reported the cumulative occurrence rates of asymptomatic VTE in patients with a variety of types of gynecologic cancer, usually in the postoperative period. For example, Clarke-Pearson et al.
References (13)
- et al.
Ovarian cancer and venous thromboembolic risk
Gynecol. Oncol.
(2005) - et al.
The natural history of postoperative venous thromboemboli in gynecologic oncology: a prospective study of 382 patients
Am. J. Obstet. Gynecol.
(1984) - et al.
Incidence of venous thromboembolism and its effect on survival among patients with common cancers
Arch. Intern. Med.
(2006) - et al.
Cancer in California: 1988–1999
(2001) Patient discharge data file documentation: full calendar years 1990–2001
(2006)- ...