Prospective Study of Determinants and Outcomes of Deferred Treatment or Watchful Waiting Among Men With Prostate Cancer in a Nationwide Cohort [Genitourinary Cancer]

JCO this week:
An interesting report from the Health Professionals Follow-up Study looking at those who "deferred treatment" for prostate cancer. They find no difference in rates of death or clinical metastases with those that pursued this approach, though 49% had been treated by 7.7 years.

This is clearly an important piece of information in the debate over prostate cancer screening and treatment decisions. However, to poke a few holes:
1. This is a study of professionals who may not represent a larger population.
2. There is no data on how many men needed long term or indefinite hormone ablation, which may well have been different between the approaches.
3. The death and metastasis rate may not have matured yet due to the well known indolent nature of this disease.
4. The hazard ratio on the multivariate analysis is informative in how broad it is (0.61- 1.75). Thus there could have been up to a 75% increase in the metastasis or death rate in the deferred treatment cohort, and the result would have remained non-significant.

That said, we obviously treat many if not a majority of prostate cancers without affecting a man's life span or QOL except in the negative with treatment related events. The next step is to better identify those in whom we can forgoe any therapy with minimal risks of progression.

Link and Abstract:

Prospective Study of Determinants and Outcomes of Deferred Treatment or Watchful Waiting Among Men With Prostate Cancer in a Nationwide Cohort [Genitourinary Cancer]: "Purpose

To examine consequences of deferred treatment (DT) as initial management of prostate cancer (PCa) in a contemporary, prospective cohort of American men diagnosed with PCa.

Participants and Methods

We evaluated deferred treatment for PCa in the Health Professionals Follow-up Study, a prospective study of 51,529 men. Cox proportional hazards models were used to calculate hazard ratios (HRs) for time to eventual treatment among men who deferred treatment for more than 1 year after diagnosis. HRs for time to metastasis or death as a result of PCa were compared between patients who deferred treatment and those who underwent immediate treatment within 1 year of diagnosis.

Results

From among 3,331 cohort participants diagnosed with PCa from 1986 to 2007, 342 (10.3%) initially deferred treatment. Of these, 174 (51%) remained untreated throughout follow-up (mean 7.7 years); the remainder were treated an average of 3.9 years after diagnosis. Factors associated with progression to treatment among DT patients included younger age, higher clinical stage, higher Gleason score, and higher prostate-specific antigen at diagnosis. We observed similar rates for development of metastases (n = 20 and n = 199; 7.2 v 8.1 per 1,000 person-years; P = .68) and death as a result of PCa (n = 8 and n = 80; 2.4 v 2.6 per 1,000 person-years; P = .99) for DT and immediate treatment, respectively.

Conclusion

In this nationwide cohort, more than half the men who opted for DT remained without treatment for 7.7 years after diagnosis. Older men and men with lesser cancer severity at diagnosis were more likely to remain untreated. PCa mortality did not differ between DT and active treatment patients."