The PSA flare phenomenon when first starting chemotherapy with docetaxel has been noted by many clinicians. To evaluate this flare in men with castrate resistant prostate cancer treated with docetaxel, researchers retrospectively evaluated the charts of 56 men who received docetaxel-based chemotherapy in three different centers from August 1999 to August 2007.
They found that there was an immediate PSA decline equal to or more than 50% in 23 (41%) of the men, PSA stabilization or PSA decline less than 50% in 16 (29%) men and PSA progression in nine men (16%).
They also found that there was also a fourth response; PSA flare in eight or 14% of the men starting chemotherapy, defined as an increase in PSA level with no symptomatic progression.
Among these men who had a PSA flare, all had osseous (bone) disease and five had additional soft-tissue disease. The PSA flare lasted a median (range) of 21 (21-42) days and it spread over a median of 1 (1-2) chemotherapy cycles.
The temporary PSA surge exceeded baseline values by a median (range) of 61.5 (12-404)%. There was a subsequent PSA response in six of the eight men and PSA stabilized in the remaining two.
The researchers concluded that of the men with castrate resistant prostate cancer (14%) had an initial PSA flare after starting docetaxel-based chemotherapy. The occurrence of PSA flare had no effect on treatment duration or outcome. With lack of clinical progression, docetaxel-based chemotherapy should be administered for at least two 3-week cycles before further decisions are made about efficacy.
BJU Int. 2008 Dec;102(11):1607-9. doi: 10.1111/j.1464-410X.2008.07873.x. Epub 2008 Oct 2; Sella A, Sternberg CN, Skoneczna, Kovel S.