Impact of clinical practice guidelines on the management for carcinomas of unknown primary site: a controlled "before-after" study.

Background: In 2002, the French Federation of Comprehensive Cancer Centers published clinical practice guidelines (CPGs) for the management of carcinomas of unknown primary (CUP).
Methods: A controlled "before-after" study at two centers (experimental in Lyon, France and control in Edmonton, Canada) to assess the impact of CPGs on CUP management. Fifty-CUP patients treated in 2000-2001, i.e. before CPG publication, and 50 patients treated in 2003-2004, were analyzed for both centers.
Results: In both groups, compliance for diagnostic workup was the same before or after CPGs publication. Non-adenocarcinoma histology and performance status (PS) < 2 were independent factors for CPGs compliance. In the experimental group, 75% of patients underwent inappropriate investigations. The proportion of patients from this group with unfavourable clinicopathologic entity and PS < or = 1, who received cisplatin-based chemotherapy did not significantly change (2000-2001: 27% vs. 2003-2004: 37.5%; P = 0.45). However, most patients treated in the pre period received organ-specific regimens, while most patients treated in the post period received taxane or gemcitabine-based regimens. Patients from the control group generally received taxane/carboplatin.
Conclusions: Our study show that simply distributing CUP CPGs did not change practice and underline the necessity to disseminate and implement CPGs, both to oncologists and organ-specialist physicians.