Subsequent metastases from prostate cancer increase treatment costs

Men with localized prostate cancer diagnosed with subsequent metastases experienced substantial cost increases for diagnostic, therapeutic and supportive care services during treatment, according to an observational cohort study published in Cancer.

“The development of metastases in patients initially diagnosed with localized prostate cancer is a seminal event of progression and results in excess morbidity, mortality and cost,” Robert I. Griffiths, MS, ScD, chief scientific officer at Boston Health Economics, and colleagues wrote.

Inflation-adjusted costs of hospital admissions for bone metastases in patients with prostate cancer are estimated to have increased from $789 million in 1998 to $1.5 billion in 2010, with the costs of admissions for skeletal-related events increasing from $190 million to $369 million during the same time period.

As a result, clinicians face the challenge of making appropriate treatment decisions while also taking into consideration the financial burden these patients face.

Observational studies have estimated real-world costs and clinical benefit from therapeutic agents; however, a total economic impact of diagnostic, therapeutic and supportive care services associated with disease progression in patients initially diagnosed with localized disease had not been investigated.

Griffiths and colleagues matched 7,482 men diagnosed with subsequent metastases at least 12 months after initial prostate cancer diagnosis to 25,709 control patients with localized disease and no metastases. The study goal included to estimate the impact of developing subsequent metastases on costs and medical resource use.

“Quantifying the total cost and resource impacts of metastatic disease provides a context for, and informs the value of, potential treatments targeting a delay in or the prevention of progression to subsequent metastases,” the researchers wrote.

Researchers followed patients from 12 months before their index date to 12 months after diagnosis, death or the end of available Medicare claims. The researchers used the claims to stratify men based on setting, type of care or services — including hospital inpatient visits, hospital outpatient/emergency room visits, physician services, home health agency, hospice, the use of a skilled nursing facility, and durable medical equipment.

Predicted total costs remained stable for the control group during the observation period (weighted mean per patient per month, $2,746; range over 24 months, 2,603-2,858).

The case group experienced an increase in costs from $2,622 (95% CI, 2,525-2,719) 12 months before diagnosis of subsequent metastasis to $4,767 (95% CI, 4,623-4,910) 1 month before the diagnosis of subsequent metastasis.

These costs peaked during the month of metastasis at $13,291 (95% CI, 13,148-13,435) and continued to be significantly higher than costs from the control group thereafter. Inpatient facility costs accounted for almost 50% of the total costs during the month of subsequent metastases (mean, $6,244; 95% CI, 6,140-6,347).

Consistent with patterns of cost, medical resource use among controls remained relatively stable during the observation period.

Although inpatient admission rates remained low in the months before diagnosis of subsequent metastases (3.5%; 95% CI, 3.2-3.9), 48.6% (95% CI, 46.4-50.9) of men in the case group were hospitalized during the month of diagnosis. Inpatient admission rates for men in the case group remained more than two-fold higher for the remainder of the observation period (12 months after metastases, 12.3%; 95% CI, 11.2-13.6).

Researchers observed up to 19-fold increases from 12 months before the diagnosis of subsequent metastases to the period around diagnosis in radiation therapy, surgery, laboratory and general medical services.

The researchers noted these increases in cost may fall upon clinicians to not only share the responsibility of controlling medical resource use and costs, but also to improve quality and treatment outcomes.

“Validated clinical pathways within electronic health care records, coordinated care strategies of enhanced communication with both physician and nonphysician stakeholders, and improvements in patient education and therapeutic compliance all are likely to play important roles,” Griffiths and colleagues wrote. “Our findings may provide a benchmark from which targets can be set for improving the efficiency of care and from which the economic impact of specific strategies can be assessed.”

These results may play a role in the debate surrounding the benefits of early disease detection and treatment, Daniel M. Frendl, MD, PhD, urologic surgery resident, and Aria F. Olumi, MD, urologist, both of Massachusetts General Hospital and Harvard Medical School, wrote in an accompanying editorial.

“Evidence of this nature is essential for developing more refined and value-based approaches to prostate cancer management that neither exclude most men from screening and early treatment nor promote high rates of overtreatment,” they wrote. – by Kristie L. Kahl

Disclosure: The study was funded by Janssen. Griffiths reports he is employed with Boston Health Economics, which received consulting fees from Janssen. Please see the full study for a list of all other researchers’ relevant financial disclosures. Frendl and Olumi report they have no relevant financial disclosures.