Metastasis-directed Therapy in Prostate Cancer: Prognostic Significance of the ESTRO/EORTC Classification in Oligometastatic Bone Disease

The diagnosis and treatment of castrate-sensitive oligometastatic prostate cancer: A review

BACKGROUND

Oligometastatic prostate cancer (OMPCa) is emerging as a transitional disease state between localized and polymetastatic disease. This review will assess the current knowledge of castrate-sensitive OMPCa.

METHODS

A review of the current literature was performed to summarize the definition and classification of OMPCa, assess the diagnostic methods and imaging modalities utilized, and to review the treatment options and outcomes. We further identify gaps in knowledge and areas for future research.

RESULTS

Currently there is no unified definition of OMPCa. National guidelines mostly recommend systemic therapies without distinguishing oligometastatic and polymetastatic disease. Next generation imaging is more sensitive than conventional imaging and has led to early detection of metastases at initial diagnosis or recurrence. While mostly retrospective in nature, recent studies suggest that treatment (surgical or radiation) of the primary tumor and/or metastatic sites might delay initiation of androgen deprivation therapy while increasing survival in selected patients.

CONCLUSIONS

Prospective data are required to better assess the incremental improvement in survival and quality of life achieved with various treatment strategies in patients with OMPCa.

Treatments and challenges in advanced prostate cancer

PURPOSE OF REVIEW

This review is designed to highlight recent research examining treatment progress in advanced prostate cancer while identifying ongoing challenges to clinical outcomes.

RECENT FINDINGS

Recent randomized trials suggest an overall survival advantage to treating some men with newly identified metastatic prostate cancer with a "triplet" of androgen deprivation therapy, docetaxel, and an androgen receptor axis-targeted agent. Questions remain about which men are best served by these combinations. Additional treatment success is being identified with prostate-specific membrane antigen positron emission tomography (PSMA)-radiopharmaceuticals, combinations involving targeted therapies, and novel manipulations of the androgen receptor axis. Challenges remain in selecting between available therapies, harnessing immune therapies, and treating tumors with emergent neuroendocrine differentiation.

SUMMARY

An expanding number of therapeutics are becoming available for men with advanced prostate cancer improving outcomes but at the same time making treatment selection more demanding. Ongoing research will be required to continue to hone treatment paradigms.

Role of local ablative treatment in oligometastatic non-small cell lung cancer: a meta-analysis

INTRODUCTION

This meta-analysis analyzed the oncologic role of local ablative treatment (LAT) in oligometastatic nonsmall cell lung cancer.

METHOD

Pubmed, MEDLINE, Embase, and Cochrane Library were searched until October, 2022. Studies comparing LAT with standard care (control) were included. Sensitivity analyses were performed including randomized controlled studies (RCTs). Subgroup analyses were performed according to specific categories and metastatic burden. The primary endpoints were overall survival (OS) and progression-free survival (PFS). Considering the median OS and PFS from landmark studies, 2-year OS and 1-year PFS rates were used to calculate pooled odds ratios (ORs).

RESULTS

A total of 20 studies (four RCTs) encompassing 1750 patients were included. Surgery and radiotherapy (60 and 90% of studies) were mainly used as LATs. Pooled ORs of OS and PFS were 3.492 (95% CI:2.612-4.699, P <0.001) and 3.743 (95% CI: 2.586-5.419, P <0.001), favoring LAT, respectively. Sensitivity analyses, including RCTs showed ORs of 4.111 ( P <0.001) and 4.959 ( P =0.001) regarding OS and PFS, favoring LCT, respectively. Pooled 1-year and 2-year OS rates were 83.8 and 58.4% in LAT arms, whereas 64.4 and 31% in control arms; pooled 1-year and 2-year PFS rates were 64.6 and 32.8% in LAT arms, and 36.1 and 10% in control arms. In subgroup analyses, the pooled ORs were 3.981 ( P <0.001), 3.355 ( P <0.001), and 1.726 ( P =0.373) in synchronous, oligopersistence, and oligoprogression/recurrence subgroups, respectively. Regarding PFS comparison, pooled ORs were 5.631 ( P <0.001), 3.484 ( P <0.001), and 1.777 ( P =0.07), respectively. According to metastatic burden categories, pooled ORs favored LAT arms in both analyses including low-metastatic and high-metastatic burden subgroups.

CONCLUSION

The present study supports the role of LAT in treating nonsmall cell lung cancer oligometastasis. The oligoprogression/recurrence disease could have less LAT benefit than synchronous or oligopersistent disease.

Stratification of Oligometastatic Prostate Cancer Patients by Liquid Biopsy: Clinical Insights from a Pilot Study

We propose a pilot, prospective, translational study with the aim of identifying possible molecular markers underlying metastatic prostate cancer (PC) evolution with the use of liquid biopsy. Twenty-eight castrate sensitive, oligometastatic PC patients undergoing bone and/or nodal stereotactic body radiotherapy (SBRT) were recruited. Peripheral blood samples were collected before the commencement of SBRT, then they were processed for circulating cell free DNA (cfDNA) extraction. Deep targeted sequencing was performed using a custom gene panel. The primary endpoint was to identify differences in the molecular contribution between the oligometastatic and polymetastatic evolution of PC to same-first oligo-recurrent disease presentation. Seventy-seven mutations were detected in 25/28 cfDNA samples: ATM in 14 (50%) cases, BRCA2 11 (39%), BRCA1 6 (21%), AR 13 (46%), ETV4, and ETV6 2 (7%). SBRT failure was associated with an increased risk of harboring the BRCA1 mutation (OR 10.5) (p = 0.043). The median cfDNA concentration was 24.02 ng/mL for ATM mutation carriers vs. 40.04 ng/mL for non-carriers (p = 0.039). Real-time molecular characterization of oligometastatic PC may allow for the identification of a true oligometastatic phenotype, with a stable disease over a long time being more likely to benefit from local, curative treatments or the achievement of long-term disease control. A prospective validation of our promising findings is desirable for a better understanding of the real impact of liquid biopsy in detecting tumor aggressiveness and clonal evolution.