Goran Ahlgren, PhD. discussed the initial results from the phase III prospective randomized trial sponsored by the Scandinavian Prostate Cancer Group, SPCG12. The purpose of this study was to use adjuvant chemotherapy to prolong the survival of men with high risk prostate cancer after radical prostatectomy. The authors hypothesized that, similar to other solid tumors, adjuvant chemotherapy may prolong survival in the adjuvant setting as it does in the metastatic setting.
In this prospective, randomized study, men with high risk pathologic and clinical features were randomized 1:1 to surveillance or 6 cycles of docetaxel (75 mg/m2) without corticosteroids or androgen deprivation therapy (ADT). High risk disease post-prostatectomy was defined as having ≥ 1 of the following features: pT2 with Gleason score 4+3 or 8-10 and positive margins in the radical prostatectomy specimen, any pT3a tumor with Gleason score 4+3 or higher, any Gleason grade 4 tumor with pT3b, or any node positive tumor if Gleason grade 4 or higher (pT2 or 3). All included patients had an undetectable PSA ≤ 0.5 ng/mL and a negative bone scan, and lymph node dissection was recommended in patients with a pre-operative PSA ≥ 10.0. The study endpoint was biochemical progression with PSA > 0.5 ng/mL confirmed by a second sample one week later. Neither ADT nor radiation was permitted in either group until after patients experienced the primary endpoint.
In total, 396 men were randomized in the study. The groups were well-balanced, with an average age of approximately 62 years, and average PSA approximately 12 prior to prostatectomy. T-stage, Gleason score, and surgical margin status were similar between groups, but lymph node metastases were slightly more common in the surveillance group. 79% of the men randomized to receive docetaxel received all 6 cycles, including approximately one third with dose reductions. During a median follow-up of 56.8 months, the rate of biochemical progression was higher in the docetaxel arm (103 men, 44.8%) than the surveillance arm (89 men, 38.9%) in the intention to treat analysis (p=0.78 for comparison of Kaplan Meier curves). A Cox multivariate analysis demonstrated that Gleason score, pT-stage, and positive surgical margin were significant predictors of progression (p<0.001, p=0.002, and p=0.009, respectively). There was a relatively high rate of febrile neutropenia at 17.9%, but no deaths from treatment.
The authors conclude that there is no benefit from the addition of docetaxel to the treatment paradigm of men with high risk prostate cancer after prostatectomy identified using pathologic and clinical criteria. They hypothesize that docetaxel may actually “trigger biochemical progression” in men with Gleason score ≤ 7. Whether this is truly the cause of the difference in biochemical progression remains to be seen, but it appears clear that there was no benefit from the addition of adjuvant docetaxel within this population. This is the second study including adjuvant cytotoxic therapy in men with high risk prostate cancer after prostatectomy that has failed to show a benefit (VA Study #553 reported by Daniel Lin, MD at the American Urologic Association Annual Meeting in May 2016). In a community eager to consider the use of cytotoxic therapy earlier in the disease process, the influence of these findings remains to be seen.
Written by: Alicia Morgans, MD.
Alicia K. Morgans, MD: Biography
Dr. Morgans is an Assistant Professor of Medicine in the Division of Hematology/Oncology. She specializes in the treatment of genitourinary malignancies, including cancers of the prostate, bladder, testis (germ cell) and penis. She received a bachelor's degree with honors in biology before going to medical school at the University of Pennsylvania School of Medicine. She then went on to complete a residency in internal medicine at the Hospital of the University of Pennsylvania in Philadelphia. Dr. Morgans completed a fellowship in Hematology/Oncology at Harvard's Dana Farber Cancer Institute and Massachusetts General Hospital Cancer Center in Boston, before moving to Nashville as an Assistant Professor in Medicine.
Dr. Morgans is a specialist in genitourinary malignancies, with special interest in advanced prostate cancer. Her research investigates the side effects of cancer treatment (including the prevention, diagnosis of, and treatment of these effects) and treatment decision-making among men with advanced prostate cancer. She also has an interest in supporting clinical research of novel treatments for genitourinary malignancies. Dr. Morgans is a member of the American Society of Clinical Oncology and the Eastern Cooperative Oncology Group.
M.D., University of Pennsylvania School of Medicine, 2006
Residency, Internal Medicine, Hospital of the University of Pennsylvania, 2009
Fellowship, Dana Farber/Harvard Cancer Center/Massachusetts General Hospital, 2012