1: Q&A

Ductal carcinoma in situ (DCIS) accounts for 20% of diagnosed breast cancers in the United States. Estrogen receptor (ER) status is an important therapeutic and prognostic indicator; however, the benefit of concomitant progesterone receptor (PR) testing remains controversial. This study evaluated the annual cost savings associated with omitting routine PR testing for DCIS.


Methods: A single-institution retrospective cohort study was performed along with a comparative national cohort analysis of the National Cancer Database (NCDB) to assess annual cost savings. P</span>atients diagnosed with DCIS in 2017 were identified through an institutional tumor registry and the NCDB. Patients without data on both receptors were excluded. Using national Medicare payment standards, the annual cost savings was determined if PR testing was omitted. The number of p</span>atients who were ER- but PR+ was assessed to determine patients who would have had a treatment impact if PR testing had been performed.


Results: A total of 156 DCIS cases were diagnosed in 2017 at our institution, 150 who had ER/PR data. A total of 120 (80%) patients were ER+, of which 104 (86.7%) were also PR+. None were ER-, PR+. Based on national Medicare payment standards, each immunohistochemical PR stain costs $124.92. If routine PR testing was omitted at our institution, there would be an annual total cost savings of $19,488. Within the NCDB, there were a total of 39,761 patients diagnosed with DCIS, of which 34,100 (85.8%) had receptor data. 29,277 (85.9%) patients were ER+, and 26,008 (76%) were both ER/PR+. Only 211 (0.6%) patients were ER-/PR+. On a nationwide scale, total cost savings of ER-only testing in one year would have been $4.3 million.
 


Conclusions: Clinical benefit of concurrent PR testing on patients with DCIS has limited benefit. Only 0.6% of patients would otherwise be eligible for hormonal therapy if PR testing had been performed (those who are ER- /PR+). This data supports the omission of routine PR testing for DCIS and nationally saves approximately $4.3 million annually. PR testing for DCIS should be considered for patients with ER- DCIS as some may be PR+ and influence the use of endocrine therapy.