It might be costly to get the PET scans but helps with prognosis and directing patients to palliative care since positive lesions in all predicts shorter overall survival.
In mCRPC, fluorodeoxyglucose (FDG) and prostate-specific membrane antigen (PSMA) PET/CT are often used in combination for selecting patients for PSMA-radioligand therapy (PSMA-RLT). Few studies have specifically assessed the prognostic value of FDG+/PSMA- lesions, which exclude patients from PSMA-RLT. Also, little is known about the significance of somatostatin receptor expression, a potential biomarker of neuroendocrine differentiation of mCRPC, which can be assessed with DOTATATE-PET/CT. 3TMPO is a prospective study in progressing mCRPC patients who were imaged with up to 3 PET tracers. Here, we report on patient’s overall survival (OS), with respect to the presence of FDG+/PSMA- and DOTATATE+ lesions.
In 3TMPO (NCT04000776, protocol in PMID 34674367), all patients had 68Ga-PSMA-617 and 18F-FDG PET/CT scans. A 68Ga-DOTATATE scan was ordered if an FDG+/PSMA- lesion was found. For all tracers, positivity was defined as lesion SUVpeak being 1.5x higher than liver SUVmean. Kaplan-Meier with log-rank test was used to assess the difference in OS between groups. Cox regression model was used to quantify the effect of factors predictive of OS.
The median [95% CI] OS of the 98 enrolled patients was 10.2 [8.5-11.8] mo. At least one FDG+/PSMA- lesion was found in 45 (45.9%) patients and their OS was shorter than that of the others: 5.6 [4.3-6.9] vs. not reached (p=0.0001). Six (16.2%) of 37 patients who underwent 68Ga-DOTATATE-PET had ≥1 DOTATATE+ lesion and their OS was shorter than that of patients without a DOTATATE+ lesion: 3.0 [2.2-3.7] vs. 6.4 [1.6-11.1] mo. (p=0.0004). Characteristics significantly associated with worse OS were ECOG, ISUP grade, number of metastases, number of lines of therapy, presence of visceral metastases, FDG and PSMA molecular tumor volumes (MTV) (p<0.05). In a multivariate analysis adjusted for the number of metastases and of treatment lines, the presence of an FDG+/PSMA- lesion increased the risk of death (HR [95% CI]=2.4 [1.4-4.3], p=0.002), and this was also significant after adjusting for both PSMA and FDG-MTV (HR [95% CI]=2.9 [1.4-5.8], p=0.003).
mCRPC patients harboring FDG+/PSMA- lesion(s) had a shorter OS than those who did not, and their prognosis was even poorer if they also had DOTATATE+ lesion(s). Upfront FDG/PSMA-PET followed by DOTATATE-PET might help clinicians to guide patient towards palliative care vs. further systemic therapy, including PSMA-RLT.
Less radiation is non-inferior, this is for low and intermediate-risk localized prostate cancer patients. Would like input from our radiation oncologists as to whether or not this adoptable?
Protons vs IMRT for localized prostate cancer showed no difference in outcome or quality of life. There will be longer f/u and other endpoints studied but the take-home message is that protons are not significantly better than photons.
Will we be replaced by AI? It seems that for radiologists, an AI system was better than the human counterpart in this study looking at prostate cancer diagnostic imaging. I doubt many of us would accept a solely computer-generated report, but this study highlights how AI may help as a supportive tool in the primary diagnostic setting. Of course, prospective validation will be needed.
10-year metastasis-free survival was 71.9% in the short-course ADT group (6 months) and 78% in the long-course ADT group (24 months). So, it seems the longer the duration, the better the outcome. 93% had a Gleason score of 7 or higher.
We know that combination PARP and antiandrogen is better than antiandrogen alone. I have wondered if we need antiancrogen on those patients. This shows that, YES, we do. The combination also was better than PARP inhibitor monotherapy in those patients carrying HRRm.
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