Prior cancer diagnosis in men with nonmetastatic prostate cancer and the risk of prostate cancer specific and all-cause mortality.

Kristina Mirabeau-Beale,Anthony Victor D'Amico,Ming-Hui Chen

doi:10.1200/jco.2013.31.6_suppl.70

Kristina Mirabeau-Beale, Anthony Victor D'Amico + Show 1 more

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https://doi.org/10.1200/jco.2013.31.6_suppl.70

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Abstract

70 Background: We evaluated the impact of a prior diagnosis of cancer on the risk of prostate cancer specific mortality (PCSM) and all cause mortality (ACM) in men with a diagnosis of non-metastatic prostate cancer (PC). Methods: Using the SEER population data registry, 166,104 men (median age: 66 [Interquartile range (IQR): 60 to 73 years]) diagnosed with prostate cancer (PC) between 2004 and 2007 comprised the study cohort. We used a Fine and Grays competing risks and Cox regression to evaluate the impact a prior cancer diagnosis (excluding non-melanoma skin cancer) had on the risk of PCSM and ACM adjusting for PSA level, Gleason score (GS), tumor (T) category, age at and year of diagnosis, race and whether initial treatment received was curative, non-curative or patients underwent active surveillance (AS) or watchful waiting (WW). Prior to the diagnosis of PC, 1,457 malignancies occurred at a median of 4.8 years. Results: After a median follow up of 2.75 years, 12,453 men died: 3,809 (30.6%) from PC. On multivariable analysis, advancing age in years was associated with an increased risk of PCSM as was Gleason score 8 to 10 PC and the use of WW/AS or non-curative therapy (all p values < 0.001). However, men with a prior cancer were significantly older (median age: 72 vs 66 years, p=0.001) and followed longer (median follow up: 3.0 vs 2.75 years, p < 0.001) and were more likely to have high-risk PC (30.1% vs 26.8%, p=0.01) based on the occurrence of Gleason 8 to 10 PC (19.2% vs 15.1%, P < 0.001) and underwent WW or AS more frequently (30.5% vs 22.5%, p<0.001). Despite these findings which would tend toward an increased risk of PCSM in these men, the adjusted risk of PCSM was significantly decreased in these men (Adjusted Hazard Ratio (AHR): 0.66 [95% Confidence Interval (CI): [0.45, 0.97]; p =0.033) while the risk of ACM was increased (AHR: 2.92 [95% CI: 2.64, 3.23]; p < 0.001) suggesting that competing risks and not curative PC treatment may be accounting for the reduction in the risk of PCSM. Conclusions: In men with a malignancy prior to the diagnosis of PC, a careful assessment of life expectancy is needed to decide on whether curative treatment for PC versus WW or AS is appropriate.

Highlights

While favorable-risk (PSA ≤ 20; T2b category or less; Gleason score ≤ 7 [1]) prostate cancer (PC) can have a long natural history [2] and is often curable, unfavorable-risk PC accounts for the majority of prostate cancer deaths [3]
Comparison of the Distribution of Clinical Characteristics for the Study Cohort Stratified by Whether a History of Cancer Existed at the Time of the PC Diagnosis or Not
Our results indicate that men who had a history of cancer prior to the diagnosis of PC were followed longer, were older, and were more likely to have GS 8 to 10 PC and undergo watchful waiting (WW) or active surveillance (AS) compared with those who did not have a history of cancer

Summary

Introduction

While favorable-risk (PSA ≤ 20; T2b category or less; Gleason score ≤ 7 [1]) prostate cancer (PC) can have a long natural history [2] and is often curable, unfavorable-risk PC (which comprises approximately 20% of cases) accounts for the majority of prostate cancer deaths [3]. Men of PC bearing age are at risk for a metachronous cancer (i.e., history of or subsequent diagnosis of another cancer). No study has investigated the impact that the comorbidity of a prior cancer has on the risk of PCSM. We used a SEER population database registry to evaluate the impact that a prior cancer had on the risk of PCSM and all-cause mortality (ACM) in men with newly diagnosed, node negative, nonmetastatic PC, adjusting for age at and year of diagnosis, race, initial treatment (curative or noncurative) or active surveillance (AS) or watchful waiting (WW), and known PC prognostic factors When considering life expectancy in men with PC, competing risks are relevant in men with favorable-risk disease [4,5,6,7,8,9,10], in order to avoid overtreatment of PC where the potential toxicities of treatment can be sustained with no prolongation in survival.

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