Patterns of Postprostatectomy Adjuvant Radiotherapy Techniques for Nonmetastatic Prostate Cancer in a Large National Cohort

National trends in the management of patients with positive surgical margins at radical prostatectomy

PURPOSE

To evaluate practice patterns of planned post-operative radiation therapy (RT) among men with positive surgical margins (PSM) at radical prostatectomy.

METHODS

We identified 43,806 men within the National Cancer Database with pathologic node-negative prostate cancer diagnosed in 2010 through 2014 with PSM. The primary endpoint was receipt of planned (RT) within a patient's initial course of treatment. We examined post-RP androgen deprivation therapy (ADT) with RT as a secondary endpoint. We evaluated patterns of post-operative management and characteristics associated with planned post-prostatectomy RT.

RESULTS

Within 12 months of RP, 87.0% received no planned RT, 8.5% RT alone, 1.3% ADT alone, and 3.1% RT with ADT. In a multivariable logistic regression model, planned RT use was associated with clinical and pathologic characteristics as estimated by surgical Cancer of the Prostate Risk Assessment (CAPRA-S) category (intermediate versus low, OR = 2.87, 95% CI 2.19-3.75, P < 0.001; high versus low, OR = 10.23, 95% CI 7.79-13.43, P < 0.001), treatment at community versus academic centers (OR = 1.24, 95% CI 1.15-1.34, P < 0.001), shorter distance to a treatment facility (OR = 0.97 for each 10-mile, 95% CI 0.96-0.98, P < 0.001), and uninsured status (OR = 1.39, 95% CI 1.10-1.77, P = 0.005). The odds of receiving planned RT were lower in 2014 versus 2010 (OR = 0.76, 95% CI 0.68-0.85, P < 0.001). There was no significant change in the use of ADT with RT. High versus low CAPRA-S category was associated with the use of ADT in addition to RT (OR = 5.13, 95% CI 1.57-16.80, P = 0.007).

CONCLUSION

The use of planned post-prostatectomy RT remained stable among patients with PSM and appears driven primarily by the presence of other adverse pathologic features.

Travel Distance as a Barrier to Receipt of Adjuvant Radiation Therapy After Radical Prostatectomy

OBJECTIVES

Following radical prostatectomy (RP), adjuvant radiation therapy (RT) decreases biochemical recurrence and potentially improves metastasis-free and overall survival for patients with high-risk pathologic features. Since adjuvant RT typically occurs daily over several weeks, the logistical challenges of extensive traveling may be a significant barrier to its use. We examined the association between distance to treatment facility and use of adjuvant RT.

MATERIALS AND METHODS

We identified 97,568 patients in the National Cancer Database diagnosed from 2004 through 2011 with cT1-4N0-xM0-x prostate cancer and found to have high-risk pathologic features (pT3-4 stage and/or positive surgical margins) at RP. Multivariable logistic regression adjusting for sociodemographic and clinicopathologic factors was used to examine the association between travel distance and receipt of adjuvant RT, defined as radiotherapy initiated within 12 months after RP.

RESULTS

Overall, 10.6% (10,346) of the study cohort received adjuvant RT. On multivariable analysis, increasing travel distance was significantly associated with decreased use of adjuvant RT, with adjusted odds ratios of 1.0 (reference), 0.67, 0.46, 0.39, and 0.32 (all P<0.001) and prevalence of use at 12.6%, 8.8%, 6.3%, 4.9%, and 3.7% for patients living ≤25.0, 25.1 to 50.0, 50.1 to 75.0, 75.1 to 100.0, and >100.0 miles away, respectively.

CONCLUSIONS

Increasing travel distance was strongly associated with decreased use of adjuvant RT in this national cohort of postprostatectomy patients with high-risk pathologic features. These results strongly suggest that the logistical challenges of extensive travel are a significant barrier to the use of adjuvant RT. Efforts aimed at improving access to radiotherapy and reducing treatment time are urgently needed.