The 2019 Annual Meeting of the European Society of Medical Oncology (ESMO) has just concluded in Barcelona, Spain.ESMO is the second most prestigious academic event in the field of oncology after ASCO. At this meeting, oncologists from around the world reported a number of research advances in new anti-cancer drugs.
So, what is the good news for prostate cancer patients that should not be missed?
Patients who are operable
Post-operative radiation therapy for prostate cancer, perhaps on hold
Several previous studies have confirmed that adjuvant radiation therapy within 4-6 months after prostate cancer surgery can reduce metastasis. There are currently two clinical approaches to radiation therapy after surgery – early postoperative radiation therapy (ART) or radiation therapy after an elevated blood PSA (SRT). PSA, whose full name is prostate-specific antigen, is an important indicator of prostate cancer.
The question of which of the two types of radiation therapy, ART or SRT, is more effective has not been answered before. This ESMO Congress, a study (RADICALS-RT) found that ART was not more effective than SRT in prolonging patient survival, with a difference of only 1% in 5-year event-free survival and increased complications (urinary incontinence, urethral stricture, etc.).
This result also suggests that radiotherapy (ART) may be less necessary early after surgery, and that it is not too late to standardize follow-up review after surgery and after PSA elevation (PSA >0.1 ng/ml or 3 consecutive rises).
However, early ART may still be necessary for some patients at higher risk, and further research is needed to screen out this group of patients.
Patients who are inoperable
Olaparib is more effective than endocrine therapy in metastatic desmoplastic-resistant prostate cancer with a BRCA mutation
For patients with metastatic desmoplastic-resistant prostate cancer (mCRPC), there was also good news at this conference.
At this ESMO Congress, results from a study (the PROfound study) showed that for patients with BRCA or ATM mutations who have disease progression after treatment with novel endocrine agents, treatment with olaparib, a PARP inhibitor, extended the median PFS (progression-free) period to 7.4 months, which is twice as long as the current clinical standard of care (abiraterone or enzalutamide). enzalutamide) by a factor of 2.
In addition to BRCA mutations, olaparib was also effective in patients carrying mutations in any of 12 genes, including FANCL, CHEK2, and CDK12. In the study, the median PFS time for patients was extended to 5.8 months, which was also better than the existing treatment.
The publication of this study also means that the PARP inhibitor olaparib can treat not only breast and ovarian cancer in women, but is also effective in prostate cancer.
PD-1/PD-L1 monoclonal antibody combined with other drugs offers multiple effective options for metastatic debulking-resistant prostate cancer
The immune checkpoint inhibitor PD-1/PD-L1 monoclonal antibody is the hottest new drug in recent times. At this ESMO meeting, multiple combinations of PD-1/PD-L1 monoclonal antibodies with other drugs were shown to be effective in studies.
- Enzalutamide→Pabrolizumab: A study showed that treatment with pabrolizumab in metastatic debulk-resistant prostate cancer (mCRPC), which developed resistance after enzalutamide treatment, still prolonged survival. Moreover, three gut microflora (akkermansia, faecalibacterium, and bifidobacterium), were able to enhance the efficacy of immunotherapy.
- Navulizumab + chemotherapy: Another study (Chenckmate 9KD) confirmed that the combination regimen of navulizumab + Rucaparib + docetaxel + enzalutamide was effective in patients who were resistant to endocrine therapy.
- Durvalumab±Tremelimumab: The CCTG IND 232 study confirmed that a dual immunotherapy combination of Durvalumab (PD-L1 monoclonal antibody) combined with Tremelimumab (CTLA-4 monoclonal antibody) was also effective in mCRPC.
Primary metastatic hormone-sensitive prostate cancer, regardless of tumor load, can be treated with docetaxel
A previous study found that for metastatic hormone-sensitive prostate cancer (mHSPC), docetaxel combined with androgen deprivation therapy (ADT) was effective in prolonging patient survival. However, this therapy is mainly suitable for patients with high tumor load, but has no significant effect on patients with low tumor load. Tumor load refers to the number of cancer cells, the size or number of cancer lesions in the body. Patients with a high tumor load usually also have a greater likelihood of cancer progression.
But many of those included in these previous studies were patients after recurrence. Doctors have been uncertain whether docetaxel should be added to ADT in patients newly diagnosed with mHSPC with a low tumor load or not. A study at this ESMO Congress provides an answer to this question.
This study, with a median follow-up of 6.5 years, found that in patients with newly diagnosed mHSPC, the application of docetaxel + ADT prolonged survival, with an overall survival (OS) time of up to 59.1 months. Comparison of different risk populations revealed that all could benefit from this combination regimen, regardless of tumor load.
The ADT therapy used in the study consisted of taking medication to suppress androgen (testosterone) production, or removing the testes. Efficacy-wise, docetaxel + ADT was not superior to second-generation ADT monotherapy (e.g., enzalutamide, etc.), but only in terms of treatment cost. For patients who cannot afford second-generation ADT drugs, they can be treated with this regimen.