Patients with advanced gynecologic cancers frequently develop malignant ascites or pleural effusions that require repeated drainage to relieve symptoms. A new retrospective cost analysis from Cedars-Sinai Cancer suggests that much of the laboratory testing routinely performed on drained fluid adds cost without providing additional clinical value [1].
Key Takeaways
- In a 10-year review of 976 paracentesis and thoracentesis procedures in patients with gynecologic cancer, laboratory testing was ordered on the fluid in 40% of cases. Nearly 80% of those orders included at least one test the investigators classified as unindicated [1].
- Unindicated testing accounted for an estimated $1,129,520 in laboratory costs over the study period. Fluid culture, cell count, and protein testing were among the most frequently unnecessary orders [1].
- Non-oncology clinicians and procedures performed in inpatient or emergency settings were substantially more likely to generate unindicated orders than gynecologic oncology clinicians or outpatient procedures. The findings point to clinician education and changes to electronic order sets as potential ways to reduce unnecessary testing [1].
Two Common Procedures, One Overlooked Cost Driver
Paracentesis and thoracentesis are commonly performed in patients with advanced solid tumors to relieve the pain, pressure, and breathlessness caused by malignant fluid accumulation in the abdomen or chest [1]. Because these procedures may be repeated throughout a patient’s treatment, clinicians must decide each time whether to drain the fluid therapeutically or also send it for laboratory analysis. In patients with an established cancer diagnosis and no new symptoms suggesting infection or another process, the study’s investigators found that routine testing—including cytology, cell counts, cultures, and chemistry panels—may provide little additional diagnostic information relative to its cost [1].
The question of whether routine fluid testing during repeat drainage constitutes unnecessary spending had not previously been examined systematically in gynecologic oncology.
Study Design and Population
The investigators conducted a retrospective economic evaluation of consecutive patients with a gynecologic cancer diagnosis who underwent at least one paracentesis or thoracentesis at a single tertiary-care academic center between 2015 and 2025 [1]. Patients with a second cancer or medical conditions that can independently cause ascites or pleural effusions, including congestive heart failure, cirrhosis, or kidney failure, were excluded. The aim was to focus on cases in which the underlying malignancy was the primary cause of the fluid accumulation [1].
A physician reviewer, with clinical input from an internal medicine hospitalist, classified each fluid-study order as indicated or unindicated based on the clinical circumstances immediately preceding the procedure. For example, cytology, culture, albumin, or cell count ordered during a therapeutic paracentesis in a patient with known ovarian cancer and recurrent ascites, without fever, unexplained leukocytosis, or new renal or hepatic abnormalities, was classified as unindicated [1]. Laboratory costs were obtained from the institution’s internal financial records, and the study followed the CHEERS reporting guideline for economic evaluations [1].
The final cohort included 216 patients with a median age of 62.9 years at diagnosis. Most had ovarian, tubal, or primary peritoneal cancer (73%), followed by endometrial cancer (19%) and cervical or vulvovaginal cancer (8%) [1]. Within the cohort, 78% of patients underwent at least one paracentesis and 45% underwent at least one thoracentesis, for a total of 665 paracenteses and 311 thoracenteses during the study period [1].
What the Fluid Testing Patterns Showed
Laboratory testing was ordered on fluid from 395 of the 976 procedures, or 40% [1]. Of those 395 procedures, 314 (79%) included at least one test that reviewers classified as unindicated [1]. The tests most frequently ordered without a supporting clinical indication were fluid culture (77% of 320 orders), cell count (73% of 326 orders), fluid protein (73% of 274 orders), and cytology (66% of 267 orders) [1]. Overall, unindicated testing accounted for an estimated $1,129,520 in laboratory costs during the 10-year study period, compared with $450,034 for tests the reviewers considered clinically indicated [1].
Two patterns emerged in relation to who ordered the tests and where the procedures were performed. Internal medicine and emergency medicine clinicians had substantially higher odds of ordering unindicated fluid studies than gynecologic oncology clinicians, who served as the reference group. Medical oncology clinicians fell between the two groups and were not statistically different from gynecologic oncology clinicians [1]. The care setting showed a similar pattern. Unindicated testing was more common when procedures were performed in the emergency department or during inpatient hospitalization than when they were performed in the outpatient clinic [1].
The authors suggest that this may partly reflect the more complex and less clearly defined clinical presentations seen in acute-care settings. They also note that some electronic health record systems bundle fluid laboratory tests into procedure orders, which could encourage testing even when individual tests are not clinically necessary [1].
Clinical and Economic Context
The rationale for questioning routine fluid testing in this population is straightforward. Once a gynecologic malignancy has been diagnosed and a patient’s ascites or pleural effusion is known to be malignant, repeat cytology, cultures, or chemistry testing during subsequent therapeutic drainage is unlikely to change management unless a new clinical concern arises [1].
Examples include fever, unexplained laboratory abnormalities, or other findings that raise concern for infection or another cause of fluid accumulation.
The authors point to previous work in patients with cirrhosis undergoing therapeutic paracentesis, in which routine ascitic fluid analysis did not demonstrate clinical benefit in asymptomatic outpatients. They suggest that these findings provide a relevant precedent for the pattern observed in gynecologic oncology [1].
The estimated $1.13 million in laboratory costs also represents only the experience of one institution and one cancer population. The authors note that gynecologic cancers account for roughly 55% of malignant ascites cases nationally but less than 10% of malignant pleural effusions. The potential cost associated with unnecessary fluid testing across other cancer types could therefore be considerably larger [1].
Study Limitations
The authors emphasize several limitations. The study was conducted at a single tertiary academic center, and the classification of testing as ‘indicated’ or ‘unindicated’ was based on retrospective review by physicians applying clinical judgment to the documented clinical circumstances. That approach is practical but may not produce the same results at other institutions with different patient populations, staffing models, or electronic ordering systems [1].
The study also cannot completely separate clinician specialty from care setting. Non-oncology orders were more common in inpatient and emergency settings, where patients may have more complex presentations and greater diagnostic uncertainty [1]. The authors call for similar analyses in other cancer types and health systems to determine whether the same pattern—high rates of unindicated fluid testing, particularly among non-oncology clinicians and in acute-care settings—is seen more broadly [1].
Implications for Practice
For gynecologic oncology and general oncology practices, the findings identify a potential target for cost stewardship. In patients with an established cancer diagnosis and a stable clinical presentation, therapeutic drainage without routine fluid laboratory testing may be reasonable when there are no new findings suggesting infection or another cause of the effusion or ascites.
The authors propose two potential interventions: clinician education, particularly for non-oncology providers caring for these patients in inpatient and emergency settings, and redesign of electronic order sets so that laboratory tests are not automatically bundled with the drainage procedure [1]. Whether these interventions reduce unnecessary testing without affecting patient care remains to be determined prospectively.
References
[1] Zhang Y, Foy O, Pipes G, Liang MI. Cost Analysis and Resource Utilization of Gynecologic Cancer-Related Thoracenteses and Paracenteses. JAMA Netw Open. 2026;9(7). doi:10.1001/jamanetworkopen.2026.24257. PMID: 42479435.
This article is intended for informational purposes for healthcare professionals and does not constitute medical advice. This summary reflects a single-institution retrospective economic evaluation; findings regarding unindicated fluid testing have not been prospectively validated or generalized across other institutions and cancer types.
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