PCNG's  PSADT & PSAV  Calculator
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--  PSA Doubling Time (PSADT) is the time it takes for the PSA to double. It is calculated with the formula: PSADT = log2 x dT/(logB-logA)  - A & B are the initial (A) and final (B) PSA measurements, and dT is the time difference between the calendar dates of the two PSA measurements. Use the calendar icons when entering the dates!
-- Some information about PSADT can be found in the website of the PCRI (Prostate Cancer Research Institute)
-- What if your PSA decreases over time? Enter the information, and the result will be preceded by a minus. You have calculated your PSA Half-Life (PSAHL), the time it takes for the PSA to half.
-- PSA Velocity (PSAV) extrapolates the increase of the PSA between the two measurements to an increase over a full year.
-- Should I know my PSADT and PSAV? That depends on who you are, on your interest knowing all what can be known about your cancer, and on your relationship with your doctor. PSADT-itis is as real as PSA-itis!

The fast PSADT & PSAV Calculator and snappy Calendar were made by Randy Marmer (Cincinnati, OH) and Hugo Ortega-Hernández (Monterrey, Mexico), respectively.  Thanks, Randy and Hugo!

Below are links to abstracts of recent articles on prostate cancer and PSADT (A-F) and on prostate cancer and PSAV (G). Links to abstracts of papers presented in San Francisco at the ASCO 2006 Prostate Cancer Symposium are in H.

A - PSADT as Indicator of Good-Risk Prostate Cancer

  1. Patients were managed initially with surveillance; those who had a PSA doubling time (PSADT) of < or = 2 years, or grade progression on repeat biopsy, were offered radical intervention. The remaining patients were closely monitored. The cohort now consists of 299 patients with good-risk .. prostate cancer. The median PSADT was 7 years, 42% had a PSADT > 10 years.

B - PSADT as Indicator of Recurrence after Local Therapy

  1. only PSADT remained a significant risk factor for <recurrence>  ..Mean 5-year <recurrence>-free survival was 99%, 95%, 93%, and 64% for patients with PSADT of 10 years or longer, 1.0 to 9.9 years, 0.5 to 0.9 year, and less than 0.5 year, respectively..
  2. in a large, multicenter study of patients who received salvage EBRT for a rising PSA level after RRP, a substantial proportion of patients with high-grade disease and/or a rapid PSA doubling time were observed to have a favorable outcome after salvage EBRT if it was administered at low PSA values.
  3. Asymptomatic patients <treated with EBRT> with Biochemical Failure <rise of PSA>, no clinical evidence of metastatic disease, a low PSA level, and long PSA doubling time were considered for follow-up without immediate hormonal therapy.

C - PSADT as Indicator of Success of EBRT after HRPC

  1. 53 patients who had developed localized hormone-refractory prostate cancer (HRPC) were treated with EBRT between 1994 and 2001. ... The 3-year and 5-year cause-specific survival rate was 94% and 87%, respectively, and the 3-year and 5-year clinical relapse-free survival rate was 78% and 56%, respectively. The univariate analysis revealed that a short prostate-specific antigen (PSA) doubling time and high PSA value at the start of RT and a high Gleason score were statistically significant factors for the risk of clinical relapse.

D - PSADT as Indicator of Metastatic Disease

  1. 128 patients had biochemical recurrence after RP; a total of 97 bone scans were obtained, of which 11 (11%) were positive, and 71 CT scans were obtained, of which 5 (7%) were positive. Men with PSA doubling time less than 6 months were at increased risk of a positive bone scan (26% vs 3%) or positive CT (24% vs 0%) relative to men with longer PSA doubling time. In men with PSA doubling time less than 6 months the risk of a positive study highly depended on PSA at the time of imaging. ... In men with PSA doubling time less than 6 months the risk of detecting metastatic disease markedly increases when PSA is greater than 10 ng/ml.

  2. 148 patients with rising PSA values after primary therapy and a PSA doubling time of <12 months enrolled on clinical protocols were followed and monitored... Metastatic events were documented in 74% (110 of 148) of patients during the follow-up period. The median progression-free survival was 19 months, with 3- and 5-year metastatic progression-free survival of 32% and 16%, respectively. T stage (P=0.07) and Gleason grade (P=0.006) at the time of diagnosis, PSA values at the time of protocol entry (P<0.001), and PSA doubling time (P<0.001) were associated with progression...These were combined into a nomogram to assess risk for an individual patient.

E - PSADT and Mortality/Survival

  1. the results of this study indicate that PSA-DT less than 3 months or the specific PSA-DT value when it is 3 months or greater is apparently a surrogate for prostate cancer specific mortality following surgery or radiation therapy... Given the relatively short interval from PSA failure to prostate cancer specific mortality and the almost 20-fold increase in cancer specific mortality in men with posttreatment PSA-DT less than 3 months, consideration should be given to promptly initiating hormonal therapy in these men ... to delay the imminent sequelae of metastatic bone disease ...
  2. 375 patients received ADT for advanced prostate cancer between 1977 and 2002, 170 were diagnosed with AIPC from 1989 to 2002, and the data of 160 patients with AIPC constitute the basis of this analysis. The final prognostic risk model included nadir PSA on androgen deprivation therapy (p 0.023), time to PSA recurrence (p 0.006) and prostate specific antigen doubling time (p=0.01). Three highly independent risk groupings were identified. The observed median cancer specific survivals were 14.0 months, 38.4 months, and 89.1 months  for low, intermediate and high risk groupings, respectively
  3. 5096 patients who had undergone RP were evaluated. During a mean follow-up of 6.0 years (median  of 5 years), 979 (19%) developed a biochemical recurrence, defined as a single postoperative PSA of at least 0.2 ng/mL. Prostate-specific doubling time (<3.0 vs 3.0-8.9 vs 9.0-14.9 vs > 15.0 months), pathological Gleason score (< 7 vs 8-10), and time from surgery to biochemical recurrence (<3 vs >3 years) were all significant risk factors for time to prostatespecific mortality.
  4. .AIPC-specific mortality was recorded in 74 of 129 patients (57.4%). Other-cause mortality was recorded in 7 men (5.4%). Median overall survival was 52.0 mo (mean, 36.0 mo) and median AIPC-specific survival was 54.0 mo (mean, 35.0 mo). In univariate regression models, all variables were significant predictors of AIPC-specific survival (p</=0.02). In multivariate models, PSADT and time from androgen deprivation to AIPC remained statistically significant (p</=0.004).
  5. 1136 men were diagnosed with localized prostate cancer ... between 1990 and 1992, and treated within 6 months of diagnosis with surgery or radiation with or without androgen withdrawal therapy. ..Patients who died of prostate cancer had a median PSA doubling time of 0.8 years... Patients who did not die of prostate cancer within 10 years of diagnosis had either no posttreatment increase in serum PSA (40%) or had a PSA doubling time longer than 1 year (44%). ...Patients whose posttreatment PSA doubling times before the initiation of androgen withdrawal therapy are less than 1 year are at high risk of dying of prostate cancer within 10 years of diagnosis.

F - Methodology of PSADT

  1. Prostate-specific antigen (PSA) doubling time (PSADT) has emerged as an important surrogate marker of disease progression and survival in men with prostate carcinoma. The literature is replete with different methods for calculating PSADT. The objective of the current study was to identify the method that best described PSA growth over time and predicted disease-specific survival in men with androgen-independent prostate carcinoma.
  2. We present here a simple graphic tool that can be used to estimate the PSADT on the basis of two increasing PSA measurements, separated by 3 to 12 months.
  3. Memorial Sloan-Kettering Cancer Center:  "Our Prostate Nomogram is designed to help physicians and patients decide which treatment approaches will result in the greatest benefit."

G - PSA Velocity: PSAV

PSA Velocity or PSAV is the increase in ng/ml/year of the PSA. It is easier to calculate than the PSADT,
but PSAVs are not as comparable as PSADTs.

  1. ..a pretreatment PSAV 2 ng/ml/yr or greater increase in PSA during the year prior to treatment is associated with a significantly higher risk of PSA failure (ASCO 2006 prostate Cancer Symposium)
  2. "..this study provides evidence to support, but does not prove the hypothesis that treatment using 6 months of AST and RT compared with RT in men with a pretreatment PSA velocity more than 2 ng/mL prolongs the time to PSA recurrence, PCSM, and ACM. Only a randomized study that can control for unknown confounding factors can provide proof that treatment using 6 months of AST and RT compared with RT prolongs the time to PSA recurrence, PCSM, and ACM in men with a rapid pretreatment PSA increase.." See Figure
    AST: Androgen-Suppression Therapy; RT: Radiation Therapy; PCSM: Prostate Cancer-Specific Mortality (PCSM), and All-Cause Mortality: ACM.
  3. The PSAV, if >0.75 ng/ml/year, seems the best parameter for a repeat biopsy.

 H- ASCO 2006 Prostate Cancer Symposium

  1. ..PSADT  < 12 months  predicted early progression to bone metastasis 
  2. ..the only predictors of cancer-related death were the PSADT and the extent of disease.
  3. ..post-treatment PSADT of less than 12 months was significantly predictive of an increased risk of death from prostate cancer
  4. ..a PSADT of 6 to 12 months were not significantly associated with length of survival following PSA failure; whereas a PSADT < 6 months and age at the time of PSA failure were
    ..the fact that over 70% of patients receiving placebo experienced lengthened PSADT suggests that, in the absence of a control arm, changes in PSADT from baseline are not a reliable measure of treatment effect in trials in early prostate cancer
  5. ..in this analysis, there was no difference in PSADT between patients with or without metastasis by CT or BS, and no PSADT cut off value that predicted metastasis
  6. ..higher PSADT was inversely associated with hazard of death

last revision: September 7, 2006.