30-Day Mortality Associated With Primary Cytoreductive Surgery In Elderly Advanced Ovarian Cancer Patients Much Higher Than Previously Reported

Researchers affiliated with the University of Washington have determined that the 30-day mortality rate associated with primary cytoreductive surgery in elderly patients with advanced ovarian cancer is much higher than previously reported.

Researchers affiliated with the University of Washington have determined that the 30-day mortality rate associated with primary cytoreductive surgery in elderly patients with advanced ovarian cancer is much higher than previously reported. There research is based upon the analysis of statistics obtained from the National Cancer Institue (NCI) Surveillance, Epidemiology, and End Results (SEER) database (collectively, the NCI SEER database).

Melissa M. Thrall, M.D., Lead Study Author; Fellow, Department of Obstetrics & Gynecology, University of Washington School of Medicine

The lead author of the study is Melissa M. Thrall, M.D., a Fellow in the Department of Obstetrics & Gynecology, University of Washington School of Medicine.

The researchers used the NCI SEER database to identify a cohort of 5,475 women aged 65 and older, who had primary debulking surgery for stage III or IV epithelial ovarian cancer which was diagnosed from 1995 through 2005. Women were stratified by acuity (i.e., average severity of illness) of hospital admission. Multivariable analysis was performed to identify patient-related and treatment-related variables associated with 30-day mortality.

The overall 30-day mortality rate was 8.2% for the 5,475 women who had surgery for advanced ovarian cancer. Women admitted on an elective basis experienced a 30-day mortality rate of 5.6% (251/4,517), while those patients admitted on an emergency basis experienced a 30-day mortality of 20.1% (168/835).  The researcher determined that 84.4% of patients were admitted on an elective basis, 15.6% of patients were admitted on an emergency basis, and 2.2% of patients had an unknown admission status.

Emergency admission was associated with older age (median of 76.9 vs. 75.1 for elective admission), higher comorbidity scores, and stage IV disease (41.9% vs. 32.9%). Women admitted on an emergency basis had surgery performed more frequently in low-volume hospitals, by low-volume surgeons, and by surgeons other than gynecologic oncologists (p value <0.001). Emergency admission was also associated with significantly less use of neoadjuvant chemotherapy (2.99% vs. 13.39%, p <0.001).

Advancing age, increasing disease stage, and increasing comorbidity score were all associated with an increase in 30-day mortality (p <.05) among elective admissions. The mortality risk was not influenced significantly by race, income, marital status and other demographic and clinical factors.

A group of women at high risk who were admitted on an elective basis included those aged 75 or older with stage IV disease, and women aged 75 or older with stage III disease and a comorbidity score of 1 or more. The high risk group experienced a 30-day mortality rate of 12.7% (95% confidence interval: 10.7%–14.9%), and accounted for 25.7% of the study population and approximately 50% of the deaths.

Low-risk patients were defined by age 65 to 74, stage III or IV disease, and a morbidity score of less than or equal to one. The low-risk patients accounted for 48.7% of the study population and experienced a 30-day mortality rate of 3.64%. The remaining intermediate patients experienced a mortality rate of 6.05%.

Based upon their analyses, the researcher concluded that age, cancer stage, and comorbidity scores may be helpful to stratify patients admitted on an elective basis by predicted postoperative mortality risk. If validated in a prospective cohort study, these factors may help identify women who may benefit from alternative treatment strategies, such as neoadjuvant chemotherapy.

The study was supported by the Marsha Rivkin Center for Ovarian Cancer Research and by the National Cancer Institute.

Sources:

• Thrall MM, et al. Thirty-Day Mortality After Primary Cytoreductive Surgery for Advanced Ovarian Cancer in the Elderly. Obstet Gynecol. 2011 Sep;118(3):537-47.

• Postop Risk of Death in Ovarian Cancer Clarified, by Charles Bankhead, Staff Writer, MedPage Today, August 24, 2011.

Related WORD of HOPE Ovarian Cancer Podcast

• Neoadjuvant Chemotherapy or Primary Surgery in Late Stage Ovarian Cancer – 10 Exciting Ovarian Cancer Research Topics From 2010, Episode 6 (Topic 8 of 10), posted August 17, 2011.