input: The following are multiple choice questions (with answers) about medical knowledge.   Prostate-specific antigen (PSA) levels can show wide fluctuations when repeatedly measured. Here we investigatewd if: (a) biopsy timing influences the prostate cancer (PC) detection rate in patients with fluctuating PSA (flu-PSA) in comparison with patients with steadily increasing PSA (si-PSA); (b) PSA slope estimated in patients with flu-PSA predicts a different risk of cancer detection; (c) flu-PSA and si-PSA patients develop PC in topographically different sites; (d) the behaviour of pre-operative PSA is an expression of a disease with defferent characteristics to the following radical prostatectomy. The study involved 211 patients who underwent at least a second biopsy after a first negative prostate biopsy. PSA Slope, PSA velocity (PSAV) and PSA doubling time (PSADT) were estimated. Flu-PSA level was defined as a PSA series with at least one PSA value lower than the one immediately preceding it. 82 patients had flu-PSA levels and 129 si-PSA levels. There were no significant differences between the two groups in terms of cancer detection, clinical or pathological stage, but the si-PSA group with cancer had a higher Gleason score. No difference was found for PSA Slope between flu-PSA patients with cancer and those without.   **Question:** PSA repeatedly fluctuating levels are reassuring enough to avoid biopsy?   (A) Yes   (B) No   (C) Maybe
output: ['(B) No <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Yes  (B) No  (C) Maybe <> possible answers', 'Prostate-specific antigen (PSA) levels can show wide fluctuations when repeatedly measured. Here we investigatewd if: (a) biopsy timing influences the prostate cancer (PC) detection rate in patients with fluctuating PSA (flu-PSA) in comparison with patients with steadily increasing PSA (si-PSA); (b) PSA slope estimated in patients with flu-PSA predicts a different risk of cancer detection; (c) flu-PSA and si-PSA patients develop PC in topographically different sites; (d) the behaviour of pre-operative PSA is an expression of a disease with defferent characteristics to the following radical prostatectomy. The study involved 211 patients who underwent at least a second biopsy after a first negative prostate biopsy. PSA Slope, PSA velocity (PSAV) and PSA doubling time (PSADT) were estimated. Flu-PSA level was defined as a PSA series with at least one PSA value lower than the one immediately preceding it. 82 patients had flu-PSA levels and 129 si-PSA levels. There were no significant differences between the two groups in terms of cancer detection, clinical or pathological stage, but the si-PSA group with cancer had a higher Gleason score. No difference was found for PSA Slope between flu-PSA patients with cancer and those without. \n   PSA repeatedly fluctuating levels are reassuring enough to avoid biopsy? <> context']