Getting More Doctors to Record a Life-Saving Prostate Cancer Calculation

What if your ability to receive the right treatment for prostate cancer came down to whether a doctor wrote down a math problem?

It sounds far-fetched, but it’s not: The math calculation in question is called prostate-specific antigen doubling time (PSADT), which is the number of months it takes for the patient’s PSA level to double.

Alicia Morgans MD, MPH

Image credit: Dana-Farber Cancer Institute

This measure of how quickly PSA is increasing is used to monitor cancer recurrence, and it’s considered one of the best predictors of outcomes for patients who have been treated for prostate cancer. Physicians use the PSADT metric to gauge a patient’s risk level and to decide if they need to start salvage androgen deprivation therapy (ADT).

So, what’s the issue? According to Alicia Morgans, MD, MPH, genitourinary medical oncologist and director of the Survivorship Program at Dana-Farber Cancer Institute, the PSADT metric is well-known to physicians, but many of them may be estimating it instead of fully calculating it—or they may be calculating the PSADT but not recording it in their notes.

“It takes time,” Morgans said in an interview with The American Journal of Managed Care. “You have to pull up the calculator, then you type in the numbers, then you type in the PSA and the date. And you have to do this several times so you can look at a period of time to calculate that doubling time. So, it does take effort.”

According to data that Morgans presented recently at the American Society of Clinical Oncology Genitourinary Cancers Symposium in San Francisco, all this leads to incomplete or inconsistent recording of PSADT data, which can mean some patients are not receiving the right care.

Methods

Morgans’ study involved a chart review of patients who recorded a HR of biochemical recurrence (BCR) from the Cardinal Health Oncology Provider Extended Network from 2018 to 2020 in the United States.1 The HR BCR definition was at least 9 months with a PSA at or above the threshold of the EMBARK trial, which had evaluated enzalutamide (NCT02319837).2 Follow-up was from the date the HR BCR was met until disease progression, the last follow-up, or death through 2022.

Physicians were asked to report PSADT in case reports, using doubling time from labs, clinical judgment, or an online calculator. If none of these were available, PSADT was calculated retrospectively based on values that had been entered into the case reports; these were listed in the study as unknown PSADT. The study also looked at time to treatment.

Results

Among 284 patients with HR BCR, the median time from prostate cancer diagnosis to end of follow-up was 39.1 months. Most patients had known PSADT. Other data were as follows:

• A higher share of patients with unknown PSADT had PSADT that rapidly doubled (61% vs 20%, P < .001)
• A higher share of patients with known PSADT (64%) compared with unknown PSADT (17%) received treatment within 60 days after the index date, with a shorter median time to treatment (1.0 month vs 6.7 months; HR 3.4; 95% CI, 2.6-4.4, P < .0001).
• Patients with known PSADT were more likely to be older with slower doubling time and get treatment than patients with unknown PSADT. The authors of the abstract wrote that this could mean treatment opportunities are being missed in clinical practice, and some patients are not getting treatment that could delay disease progression.

Explaining the Results

Morgans suspects that many doctors are looking at the numbers and dates and making an estimate about the approximate doubling time, “which is probably overestimating the doubling time as we suggest in the paper…. They’re doing some form of [PSADT], but they’re not doing it in a structured, standardized way."

Could software in the electronic health record be modified to perform the PSADT calculation for the doctors? “That would be fantastic,” Morgans said. “That would be very, very helpful, because if there is a standardized approach to calculation that gets you the true number, then that would be used in the regulatory approval of the drugs that we use for those high-risk patients with the shorter doubling time.”

Adding a quality measure based on whether doctors record PSADT is another possibility, but that also raises issues of administrative burden.

Morgans noted that the study also revealed that if doctors overestimate the doubling time, they in turn also underestimate how aggressive the cancer is; thus, they underestimate the risk of metastasis in that individual patient.

If a patient’s calculation is off and not listed as high risk—when in fact the cancer is aggressive—does that mean the patient may not be approved for the treatment needed?

“True,” Morgans said. “It may also lead to [the physician] not treating the patient when it’s absolutely appropriate, and they’re not taking that opportunity to prevent metastasis, which is associated with all kinds of other complications—pain, bleeds, other therapies.”

She added, “It can also be quite expensive for other interventions.”

Performing the calculation correctly doesn’t add any cost or inconvenience to the patient—it’s strictly a matter of getting doctors to do PSADT correctly and to record it consistently. Morgans said because the study was relatively small, the group doesn’t have information on which doctors are most likely to do PSADT correctly and consistently.

“I can't say, except to say that I think every doctor is actually at risk for not calculating it because of the time issues, because of the pressures that they have,” Morgans said.

References

1. Morgans AK, Touya M, El-Chaar NN, et al. Impact of physicians’ awareness of prostate-specific antigen doubling time (PSADT) on treatment (Tx) decisions in high-risk (HR) biochemically recurrent (BCR) prostate cancer (PC). J Clin Oncol. 43(suppl 5): Abstract 354. doi:10.1200/JCO.2025.43.5_suppl.354
2. Freedland SJ, Luz MdA, DeGiorgio U, et al. Improved outcomes with enzalutamide in biochemically recurrent prostate cancer. N Engl J Med. 2023;389(16):1453-1465. doi:10.1056/NEJMoa2303974