Bone marrow involvement in patients with metastatic castration sensitive prostate cancer

Mechanism and clinical progression of solid tumors bone marrow metastasis

The rich blood supply of the bone marrow provides favorable conditions for tumor cell proliferation and growth. In the disease's early stages, circulating tumor cells can escape to the bone marrow and form imperceptible micro metastases. These tumor cells may be reactivated to regain the ability to grow aggressively and eventually develop into visible metastases. Symptomatic bone marrow metastases with abnormal hematopoiesis solid tumor metastases are rare and have poor prognoses. Treatment options are carefully chosen because of the suppression of bone marrow function. In this review, we summarized the mechanisms involved in developing bone marrow metastases from tumor cells and the clinical features, treatment options, and prognosis of patients with symptomatic bone marrow metastases from different solid tumors reported in the literature.

Metronomic cyclophosphamide for bone marrow carcinomatosis in metastatic castration-resistant prostate cancer

PURPOSE

In some patients with prostate cancer, bone marrow carcinomatosis develops later in the course of the disease, which has a poor prognosis. These are often heavily pretreated patients in the castration-resistant situation for whom there are no other therapeutic options, because either all available systemic therapies have already been used or the use of one is not possible due to the cytopenias associated with bone marrow carcinomatosis. In our literature search, there are no data on this treatment in the setting available, especially no clinical trial or even randomized data. This case series is to determine the clinical efficacy of metronomic cyclophosphamide in patients with metastatic castration-resistant prostate cancer and bone marrow carcinomatosis, particularly with regard to stabilization of the blood count (thrombocytopenias) and thus the possibility of further (more toxic) lines of therapy.

METHODS

Retrospective unicenter analysis was performed on eleven patients between 54 and 84 years of age on metronomic cyclophosphamide for bone marrow carcinomatosis in metastatic castration-resistant prostate cancer treated at a Swiss cancer center between 2014 and 2023.

RESULTS

Eleven patients received metronomic cyclophosphamide for varying periods of time; the majority had severe cytopenias (especially thrombocytopenias). Partially hematologic stabilization was achieved with administration of further systemic therapies.

CONCLUSION

Our case series demonstrates that the use of metronomic cyclophosphamide allows hematologic stabilization for months, benefiting patients who had already received all available therapies for metastatic castration-resistant prostate cancer. Alternatively, it may act as bridging therapy to allow consecutive administration of more toxic therapies with proven survival benefit.

Two cases of prostate cancer with disseminated carcinomatosis of the bone marrow treated with novel hormonal agents

Introduction

Disseminated carcinomatosis of the bone marrow in prostate cancer is rare and has a poor prognosis. Although strong evidence suggests that novel hormonal agents improve the prognosis of metastatic prostate cancer, their effectiveness in cases of disseminated carcinomatosis of the bone marrow remains unclear.

Case presentation

We encountered two cases of prostate cancer with disseminated carcinomatosis of the bone marrow at the time of initial diagnosis. One patient was treated with enzalutamide, abiraterone, docetaxel, cabazitaxel, denosumab, and radium-223 and died 38 months after the initial diagnosis. The other patient was treated with apalutamide and denosumab, and had progression-free survival for 17 months after the initial diagnosis.

Conclusion

These results suggest that novel hormonal agents may improve the prognosis of prostate cancer even in patients with disseminated carcinomatosis of the bone marrow.