A Case Report of a Patient with Multiple Bone Metastases from Prostate Cancer Achieving Complete Remission for 6 Years after Chemotherapy Combined with Endocrine Therapy

Abstract

Introduction

Prostate cancer is one of the most common malignant tumors in men, and bone metastasis is a common complication that severely affects patients’ quality of life and survival rates.

Case Presentation

This article reports a case of a patient with multiple bone metastases from prostate cancer who achieved complete remission and survived for 6 years following chemotherapy combined with endocrine therapy.

Conclusion

By detailing the patient’s treatment process and follow-up results, the article explores the application value of chemotherapy combined with endocrine therapy in the management of bone metastases in prostate cancer.

Background

Prostate cancer is one of the most common malignant tumors in men, characterized by high incidence and mortality rates. According to global cancer statistics, prostate cancer ranks second in incidence among male cancers, following lung cancer [1]. The early symptoms of prostate cancer are often subtle and may only be detected when the disease has progressed to an advanced stage. Bone metastasis is a common complication in patients with prostate cancer, with approximately 70% of patients with advanced prostate cancer experiencing bone metastasis [2]. Bone metastasis not only leads to severe bone pain but can also cause complications such as pathological fractures and hypercalcemia, significantly affecting the patient’s quality of life and greatly shortening their survival time [3].

The treatment strategies for bone metastasis in prostate cancer primarily include endocrine therapy, chemotherapy, radiotherapy, and bone-modifying agents [4]. Endocrine therapy works by inhibiting the production of androgens or blocking their effects to control the progression of prostate cancer [5]. However, long-term endocrine therapy may lead to castration-resistant disease, where prostate cancer cells continue to grow and spread in the absence of androgens [5, 6]. Chemotherapy involves the use of cytotoxic drugs to kill cancer cells and is commonly employed in patients who have failed endocrine therapy [7]. In recent years, the combination of chemotherapy and endocrine therapy has shown promising efficacy in the treatment of bone metastasis from prostate cancer [8]. Studies indicate that the combined use of chemotherapy and endocrine therapy can extend patients’ progression-free survival and overall survival [9]. However, despite the continuous advancements in treatment options, achieving long-term complete remission in patients with bone metastasis from prostate cancer remains a significant challenge.

This case report describes a patient with multiple bone metastases from prostate cancer who achieved complete remission and maintained 6 years of disease-free survival after receiving a combination of chemotherapy and endocrine therapy. The successful treatment of this case provides important clinical insights for the comprehensive management of bone metastasis in prostate cancer.

Case Presentation

Basic Patient Information

The patient is a 71-year-old male who was admitted to the orthopedic department on September 10, 2018, due to “lower back and sacral pain for over a month.” He has no significant past medical history and no family history of hereditary diseases. Physical examination revealed tenderness in the left lumbar and paravertebral muscles, as well as tenderness in the left buttock.

Laboratory tests showed a significant elevation in prostate-specific antigen (PSA), reaching 131.50 ng/mL. Imaging studies included:

• 1.MRI: multiple low-signal lesions were observed in the spinous processes of the lumbar vertebrae and within the sacral bone, with abnormal signal in the L2 vertebral body; CT was recommended if necessary (Fig. 1).
• 2.X-ray: no obvious fractures or bone destruction were noted in the sacrococcygeal vertebrae. Patchy high-density shadows were seen in the right sacroiliac joint and ilium, warranting correlation with clinical findings (Fig. 2).
• 3.CT: multiple patchy, uneven high-density shadows were observed in the sacrococcygeal region and both iliac bones (Fig. 3).
• 4.MRI (whole-body diffusion, similar to PET): consideration of prostate cancer was made, with restricted diffusion noted in multiple vertebrae, ribs, sacrococcygeal bones, and both hip bones, suggesting metastasis (Fig. 4–6).

Fig. 1.

Lumbar spine MRI: multiple abnormal signals in the lumbar spinous processes, sacrum, and L2 vertebral body. Metastasis is considered.

Fig. 2.

Sacrococcygeal X-ray: right sacroiliac joint, iliac bone metastasis.

Fig. 3.

Sacrococcygeal CT: multiple metastases in the sacrococcygeal region and bilateral iliac bones.

Fig. 4.

MRI: prostate cancer is considered; multiple vertebral, rib, sacrococcygeal, bilateral iliac, acetabular, and ischial metastases are considered.

Fig. 6.

MRI – yellow arrow: prostate cancer lesion; green arrow: sacral metastasis.

Fig. 5.

MRI – yellow arrow: prostate cancer lesion; green arrow: coccygeal metastasis; red arrow: iliac bone metastasis.

On September 23, 2018, a prostate biopsy was performed under ultrasound guidance, with pathology results indicating adenocarcinoma with a Gleason score of 4 + 5 = 9 (12 cores taken). Immunohistochemistry results were consistent with adenocarcinoma.

Diagnosis

Based on the patient’s clinical presentation, laboratory test results, and imaging studies, the diagnosis is multiple bone metastases from prostate cancer (T4N1M1, Gleason score 9).

Process of Treatment

Initial Treatment

After the diagnosis, the patient initially received endocrine antitumor therapy with goserelin acetate and bicalutamide, along with zoledronic acid for the treatment of bone metastases. Following the initial treatment, the patient’s PSA level significantly decreased to 0.02 ng/mL, and there was a slight relief in the lower back and sacral pain symptoms.

Chemotherapy

Subsequently, the patient’s PSA levels began to rise, reaching 3.53 ng/mL on June 1, 2019. On June 30, 2019, the patient received a chemotherapy regimen consisting of docetaxel combined with prednisone. The specific regimen was docetaxel 75 mg/m² every 3 weeks, and prednisone 5 mg twice daily. A total of six cycles of chemotherapy were administered. During the chemotherapy, the patient tolerated the treatment well and did not experience any severe adverse reactions.

Endocrine Therapy

During chemotherapy, the patient also received endocrine therapy, which included a monthly injection of goserelin acetate (3.75 mg) and oral administration of bicalutamide (50 mg once daily) along with abiraterone (250 mg, four tablets once daily). After completing chemotherapy, the patient continued with the endocrine therapy.

Follow-Up and Outcomes

After six cycles of chemotherapy combined with endocrine therapy, the patient’s PSA levels significantly decreased and remained within the normal range, with marked relief of lumbosacral symptoms. Due to cost considerations, the patient switched to an endocrine therapy regimen of leuprolide acetate (3.75 mg) plus bicalutamide (50 mg once daily) and abiraterone (250 mg, four tablets once daily) starting in January 2020, along with zoledronic acid to manage bone metastasis. Throughout the treatment period, the patient consistently took a homemade tonic from our hospital to boost immunity. During follow-up, the patient had monthly PSA checks. As of March 2024, the patient’s PSA levels have consistently remained within the normal range (Fig. 7), and the lumbosacral pain symptoms have resolved. The patient enjoys a good quality of life and has not experienced any further prostate cancer-related symptoms. Timeline and key events are shown in Table 1.

Fig. 7.

Trend of blood TPSA changes.

Table 1.

Timeline and key events

Timeline	Key events
Sep 2018	Initial diagnosis of multiple bone metastases from prostate cancer
Sep 2018–May 2019	Initial endocrine therapy (goserelin + bicalutamide + zoledronic acid)
Jun 2019–Dec 2019	Chemotherapy (docetaxel + prednisone) + continued endocrine therapy
Jan 2020–Mar 2024	Modified endocrine therapy (leuprolide + bicalutamide + abiraterone)
Mar 2024	Sustained complete remission with PSA <0.1 ng/mL

Discussion

Prostate cancer is one of the most common malignant tumors in men, and bone metastasis is a significant marker of disease progression [3]. For patients with prostate cancer and bone metastases, the combination of chemotherapy and endocrine therapy has been widely applied in clinical practice and has demonstrated significant efficacy [10, 11]. In this case report, the patient achieved a sustained disease-free survival time of 6 years following chemotherapy combined with endocrine therapy, which holds important clinical significance.

Docetaxel, as a microtubule inhibitor, prevents the depolymerization of microtubules, thereby inhibiting the division and proliferation of cancer cells. It has been shown to have significant efficacy in the treatment of prostate cancer [12]. Multiple studies have indicated that the chemotherapy regimen combining docetaxel with prednisone can significantly extend the overall survival of patients with prostate cancer and improve their quality of life [13, 14]. Androgen deprivation therapy (ADT) is one of the standard treatment options for patients with prostate cancer and bone metastases [3]. Androgens play a crucial role in the growth and survival of prostate cancer cells. By inhibiting androgen production or blocking their receptors, effective control of cancer cell growth can be achieved [15]. The combined use of leuprolide and bicalutamide can more comprehensively suppress the effects of androgens, thereby enhancing treatment efficacy [16, 17]. The synergistic effect of chemotherapy and endocrine therapy plays a key role in the treatment of patients with prostate cancer and bone metastases. Chemotherapy primarily works by inhibiting microtubule polymerization, which prevents cell division, suppresses cancer cell proliferation, and induces apoptosis. In contrast, endocrine therapy inhibits the production and action of androgens, thereby suppressing the growth and proliferation of prostate cancer cells. The combined use of these two approaches can block cancer cell growth and spread at different levels, improving treatment outcomes and effectively controlling tumor progression, ultimately extending patient survival. The synergy between chemotherapy and endocrine therapy may stem from dual targeting of androgen-dependent and independent pathways [18]. Docetaxel disrupts microtubule dynamics in rapidly dividing cells, while ADT suppresses androgen receptor signaling – a mechanism validated in recent trials integrating novel anti-androgen-like darolutamide [19].

Although chemotherapy and endocrine therapy are effective, they are also associated with certain side effects. Common side effects of chemotherapy include bone marrow suppression, gastrointestinal reactions, and hair loss [20]. Endocrine therapy may lead to issues such as hot flashes, osteoporosis, and metabolic disorders [21]. Long-term use of zoledronic acid may increase osteonecrosis risk, necessitating dental surveillance [21]. Similarly, abiraterone’s mineralocorticoid effects mandate periodic monitoring of blood pressure and potassium levels. In this case, the patient did not experience severe side effects during treatment, which may be attributed to individual differences, reasonable adjustments in the treatment regimen, and good supportive care. Effective management of side effects is crucial for improving the patient’s quality of life and treatment adherence.

In the treatment of prostate cancer, the issue of drug resistance poses a significant challenge. ADT is initially effective, but over time, some patients may develop castration-resistant prostate cancer [10, 22]. In this case, the patient did not exhibit significant drug resistance after receiving chemotherapy combined with endocrine therapy, which may be attributed to several factors. First, the combination of chemotherapy and endocrine therapy may have delayed the onset of resistance. Second, individual patient differences and treatment adherence could also play a role. Lastly, the proprietary blood-nourishing and immune-boosting ointment developed by our hospital may have contributed to enhancing the patient’s immunity.

The treatment of prostate cancer should be individualized based on the specific circumstances of each patient. In this case, the patient underwent a detailed medical history collection and comprehensive examination prior to receiving chemotherapy combined with endocrine therapy, leading to the development of a personalized treatment plan. During the treatment process, adjustments to the treatment regimen were made promptly based on the patient's response and adverse reactions, ensuring both efficacy and safety. This individualized treatment model not only enhances treatment outcomes but also reduces treatment-related adverse effects, making it worthy of clinical promotion. In this case, the patient achieved a continuous disease-free survival time of 6 years after receiving chemotherapy combined with endocrine therapy, which is relatively rare among patients with bone metastases from prostate cancer. The possibility of long-term survival depends not only on the choice of treatment regimen but also closely relates to various factors such as the patient's overall health status and treatment adherence. Research on similar cases can help further explore the key factors influencing long-term survival and optimize treatment strategies.

The successful complete remission in this case is largely attributed to long-term follow-up. Regular monitoring of PSA levels and imaging studies allows for the timely detection of recurrence signs and the adjustment of treatment plans, ensuring the durability of treatment outcomes. In this case, the patient did not undergo regular imaging follow-ups due to financial constraints; however, the patient’s PSA levels remained within the normal range, and symptoms in the lumbar and sacral regions completely resolved. In resource-limited settings, reliance on PSA monitoring as a surrogate for imaging is pragmatic. Recent studies suggest that serial PSA measurements combined with alkaline phosphatase assays may provide cost-effective alternatives for tracking disease progression [23]. The patient reported improved mobility and resumed daily activities (e.g., gardening), underscoring the importance of functional outcomes in evaluating treatment success. Additionally, during follow-up, it is important to pay attention to the patient’s quality of life and psychological well-being, providing comprehensive support and assistance.

This case report provides valuable insights into the treatment of patients with bone metastases from prostate cancer. The combination of chemotherapy and endocrine therapy not only significantly reduces PSA levels and alleviates symptoms but also extends the survival of patients and improves their quality of life. For patients who do not respond well to ADT alone, the combination of chemotherapy and endocrine therapy is a worthwhile option to consider.

The patient’s use of a homemade immunity-boosting tonic warrants further investigation. Although no direct evidence links the tonic to clinical outcomes, its potential role in mitigating treatment-related fatigue or enhancing immune surveillance could be explored in future studies.

The successful complete remission in this case provides valuable experience for the treatment of patients with multiple bone metastases from prostate cancer. While this case demonstrates promising outcomes, the findings are inherently limited by its single-subject design. Extrapolating these results to broader populations requires caution, as individual variations in tumor biology, treatment adherence, and comorbidities may influence therapeutic efficacy.

Further research is needed to validate its general applicability. Future research directions may include (1) exploring the efficacy of chemotherapy combined with endocrine therapy in patients with prostate cancer at different stages and with various genotypes. (2) Investigating the mechanisms of resistance and strategies for prevention. (3) Optimizing treatment regimens to reduce side effects and enhance patients’ quality of life. (4) Conducting large-scale clinical trials to validate the findings reported in this case.

Emerging therapies such as PSMA-targeted radioligands and PARP inhibitors are reshaping the therapeutic landscape for metastatic castration-resistant prostate cancer. These modalities could complement traditional regimens in future combinatorial approaches.

The CARE Checklist has been completed by the authors for this case report, attached as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000545854).

Statement of Ethics

Ethical approval is not required for this study in accordance with local or national guidelines. Written informed consent was obtained from the patient for publication of the details of their medical case and any accompanying images.

Conflict of Interest Statement

The authors have no conflicts of interest to declare.

Funding Sources

This research was supported by the funding of Changshu Science and Technology Bureau (CS202123).

Author Contributions

Ke Xu conceived and designed the study. Zhicheng Lu and Jian Sun collected data. Zhicheng Lu analyzed data. Jian Sun wrote the manuscript. Ke Xu made critical revisions for the original manuscript. All authors reviewed the manuscript.

Funding Statement

This research was supported by the funding of Changshu Science and Technology Bureau (CS202123).

Data Availability Statement

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.