CHALLENGES IN THE DIAGNOSIS OF SOFT TISSUE SARCOMA: A COMPARISON OF PRE-DIAGNOSIS CONDITIONS AND HEALTH CARE RESOURCE USE BETWEEN KNOWN SOFT TISSUE SARCOMA PATIENTS AND MATCHED CONTROLS IN CLAIMS DATA
Soft tissue sarcoma (STS) is a heterogeneous group of rare solid tumors that arise from soft tissues, such as muscle, fat, nerves and blood vessels. Since these tumors occur in many different locations of the body, STS is challenging to diagnose. This study was designed to compare health care encounters between STS patients and non-cancer matched controls.
Method: STS patients with at least two ICD-9 codes of 171.x on two different days between July 1, 2004 and March 30, 2014 were identified from the Truven MarketScan claims database. The first 171.x ICD-9 code was defined as index diagnosis. The control cohort was matched on age, gender, geographic region, health plan type, each ICD-9 code in the Charlson Comorbidity Index (CCI) (excluding all cancer codes) and employment status at the matched STS patient index date. Differences between factors during the 6-month pre-index period were tested by t-test for continuous variables and Chi-square or Fisher’s exact test for categorical variables.
Result: Among 17009 eligible STS patients in the database, 7826 patients were able to be matched to a control. The matched population had a mean age of 57.8 (SD=16.9), 51.99% were male, and had a mean CCI of 0.4 (SD=0.8). A significantly greater (p<0.05, ≥5% difference) percentage of patients with STS had ICD-9 codes for neoplasms of uncertain behavior of the skin (15.15% vs 0.0% ), neoplasm of unspecified nature of bone soft tissue and skin (8.36% vs. 0%), actinic keratosis (8.70% vs. 1.37%), pain in soft tissues of limb (10.53% vs. 5.20%), local superficial swelling mass or lump (13.24% vs. 0.22%), and abdominal pain or swell mass (12.64% vs. 4.22%). A significantly greater (p<0.0001) percentage of STS patients had inpatient (15.55% vs. 7.67 %), ER (18.72% vs 14.58%) and physician visits (94.26% vs 91.26%).
Patients diagnosed with STS are significantly more likely to have health care visits and are more frequently diagnosed with conditions that may have similar presentation to STS than matched controls, supporting anecdotal evidence of challenges in reaching an accurate diagnosis. Further work is needed to improve the early detection and diagnosis of STS.