SIU 2018: Management of Grade Group 2 Prostate Cancer, Surveillance

Seoul, South-Korea ( A case of intermediate risk prostate cancer was presented and various treatment options were discussed in this session. In this presentation management with active surveillance was recommended. The hypothetical patient was a 65-year-old healthy man, who is a non-smoker, with mild hypertension, and a mild decrease of erectile function with an International Prostate Symptom Score (IPSS) of 12. He had a positive family history with his father being diagnosed with prostate cancer at age 75, and treated with brachytherapy in 2005.  This man had a normal digital rectal examination (DRE), showing a 40 cc prostate gland. His PSA is 5.5 ng/ml (increased from 3 ng/ml in 2015, to 4.2 ng/ml in 2017).  His transrectal ultrasound (TRUS) demonstrated a 45 cc prostate. He underwent a systematic biopsy demonstrating Gleason 7 (3+4) in 2/12 cores, in the right peripheral zone, with 10% pattern 4, and 20% core involvement. Additionally, the biopsy demonstrated a Gleason 6 (3+3) lesion in the right apex peripheral zone with 15% core involvement. Lastly, the patient underwent a multiparametric MRI of the prostate demonstrating a 13 mm PIRADS 3 right mid posterior peripheral zone lesion.

Dr. Sung Kyu Hong debated why active surveillance is the right choice for this individual. He began his presentation, showing a study published in 1988, where 153 patients with localized prostate cancer were managed by pure watchful waiting. After seven years of follow-up, the prostate cancer-specific mortality was only 4%1, demonstrating that even without the strict monitoring protocol entailed in active surveillance, these patients overall do quite well.

Intermediate risk prostate cancer is a heterogeneous group with different prognosis. Intermediate risk disease is divided to favorable and unfavorable. In the favorable subtype, there is only one intermediate risk factor, with a Gleason score of 3+4 and less than 50% of positive biopsy cores. In the unfavorable intermediate-risk disease, there are several intermediate risk factors, the Gleason score is 4+3, and more than 50% of biopsy cores are positive. The recommended therapy for favorable disease is dose-escalated external beam therapy alone or brachytherapy alone in select cases. For unfavorable disease, the recommended treatment is dose-escalated external beam radiotherapy and short-term androgen deprivation treatment, or combined brachytherapy and external beam radiotherapy with or without short-term androgen deprivation therapy2. There is a clear difference between favorable and unfavorable intermediate-risk disease in terms of PSA recurrence-free survival and cancer-specific survival, which are significantly worse for unfavorable intermediate-risk disease.

There is also data showing that there is no difference in the biochemical recurrence-free survival between low-risk disease and favorable intermediate-risk disease3, as seen in figure 1.

UroToday SIU2018 Biochemical recurrence free survival in low risk and favorable intermediate risk prostate
Figure 1: Biochemical recurrence-free survival in low risk and favorable intermediate-risk disease:

Data from Sunnybrook in Toronto, Canada, also show that there is an extremely small difference in the ten-year cancer-specific survival between low-risk disease (98%) and favorable intermediate-risk disease (97%).4

Lastly, Dr. Sung Kyu Hong quoted the National Comprehensive Cancer Network (NCCN) guidelines stating that for favorable intermediate-risk disease, one of the possible treatment options is active surveillance. According to Dr. Sung Kyu Hong, the fact that this therapy is recommended in the guideline should give urologists and patients the needed confidence to choose this form of treatment.

Presented by: Sung Kyu Hong, Seoul National University, Bundang Hospital

1. George NJR. Lancet 1988
2. Zumsteg ZS et al. Lancet Oncol 2012
3. Lee H et al. Clin Gen Cancer 2017
4. Musunuru HB et al. J Urol 2016

Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre  Twitter: @GoldbergHanan at the 38th Congress of the Society of International Urology - October 4- 7, 2018 - Seoul, South Korea

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