THE "NEW" PROSTATE CANCER INFOLINK

A newly published paper in the journal PLoSOne has addressed the future prevalence of various different clinical states of prostate cancer here in the USA, along with the mortality of the men diagnosed with prostate cancer. The authors’ primary intent was to use this model as a tool in thinking about issues related to the enrollment of patients into and the times to complete specific types of clinical trial, but for the patient community the data are of interest in and of themselves.

The full text of this paper by Scher et al. is freely available on line (as is the full text of every paper published in PLoSOne).

Scher and his colleagues broke prostate cancer down into a set of eight “clinical states” in four groups, as follows:

Localized forms of prostate cancer

• Newly diagnosed, localized disease
• Newly diagnosed, locally advanced disease
• Rising PSA (non-castrate), i.e., biochemical failure after first-line therapy

Non-metastatic, castrate-resistant forms of prostate cancer (nmCRPC)

• Rising PSA (non-castrate), i.e., biochemical failure after hormonal therapy but with no signs of metastasis

Hormone-sensitive, metastatic forms of prostate cancer

• Newly diagnosed, metastatic disease

Metastatic, castration-resistant forms of prostate cancer (mCRPC)

• Asymptomatic/minimally symptomatic forms of mCRPC that have not been treated with or not progressed on chemotherapy
• Symptomatic forms of mCRPC that have not been treated with or not progressed on chemotherapy
• Forms of mCRPC that have progressed on or after chemotherapy

The full details of what is and is not included in each of these clinical states is given in Table 1 of the original paper

Using available data from 1990 through 2009, the authors then developed what they refer to as a “dynamic transition model” allowing them to project the numbers of patients who can be expect to be grouped into each of the clinical states for the period from 209 through 2020.

Table 3 of the paper provides a breakdown of the estimated numbers of patients who are newly found to be in (incidence) or living with (prevalence) each of the eight clinical states abovementioned in 2009 (the base model) and 2020. Table 4 and Figure 2 of the paper give indications of the hypothetical impact of significant forms of new treatment for men with nmCRPC or mCRPC.

We obviously aren’t going to get into all of the details in this brief commentary, but here are some of the more interesting projections:

• The estimated prevalence of prostate cancer (i.e., the number of men living after a diagnosis of prostate cancer) in 2020 will be 3,072,480.
• The estimated incidence of mCRPC (i.e., the number of new cases of mCRPC) was 36,100 in 2009 and will be 42,970 in 2020.
• The estimated all-cause mortality among men diagnosed with prostate cancer was 168,290 in 2009 and will be 219,360 in 2020.
  • In 2009, it is estimated that 20.5 percent of the deaths (c. 34,500 deaths) were among men who had mCRPC.
  • In 2020, it is estimated that 19.5 percent of the deaths (c. 42,775 deaths) will be among men who had mCRPC.
• 86 percent of men who move into one of the mCRPC states come from the nmCRPC state.
• If there are significant new forms of treatment for patients in the nmCRPC states, progression to mCRPC will be reduced, and there will be a 12 percent decrease in the incidence of mCRPC by 2020 relative to 2009, with a sustained decline in mCRPC mortality.
• The model does not permit estimation of prostate cancer-specific mortality.

In looking at these data, it is important to understand that the estimated increases in prevalence, incidence, and mortality from 2009 to 2020 have more to do with the numbers of men at risk for prostate  cancer (as “baby boomers” get older) than it does with anything else. It also has to be noted that if enforcement of the current USPSTF guidance on screening for prostate cancer is truly implemented, then this could seriously impact the numbers of men who are actually initially diagnosed with localized as opposed to non-localized forms of prostate cancer by 2020.

Filed under: Diagnosis, Living with Prostate Cancer, Management, Risk, Treatment | Tagged: estimate, incidence, model, mortality, prevalence |