An exceptional prostate cancer case: Importance of cancer screening

1 INTRODUCTION

Prostate cancer is the most common malignancy in male population.¹ It ranks second in cancer-related deaths after lung cancer.² Although the triggering causes of prostate cancer are not yet fully understood, genetic factors, chronic inflammation and infection, high-fat diet, smoking, alcohol use, and obesity are among the possible triggers of prostate cancer.

In this study, we aimed to present a prostate cancer case in an elderly man with constitutional symptoms that investigated for fever of unknown origin.

2 CASE REPORT

A 69-year-old man presented to our institution for fever lasting more than a month. He had no other signs of infection. He lost about 15 kg within 3 months. Patient history was not remarkable of comorbidities, such as diabetes mellitus, hypertension, or cardiac diseases. On physical examination, patient looked well in appearance. His fever was 37.6°C. Heart rate was 102/min, breathing rate was 18/min and systolic and diastolic blood pressures were 125 and 78 mmHg, respectively. He had dry skin. Prostate was hard and rough surfaced in rectal examination. Other physical examination findings were normal.

Laboratory analyses revealed a mild hypercalcemia (10.5 mg/dl, 11 mg/dl after correction according to serum albumin level). He was anemic (Hb: 9 g/dl, compatible with anemia of chronic disease), erythrocyte sedimentation rate (ESR) was elevated to 140 mm/h, C-reactive protein was 70 mg/dl, uric acid was 12.2 mg/dl. Other laboratory findings were within normal range.

After initial tests, a bunch of serologic studies ordered. Serum angiotensin-converting enzyme and beta 2 microglobulin were normal. Brucella, Ebstein Barr Virus, and other tests for infectious causes were negative. Carcino embriogenic antigen, alpha fetoprotein, and CA125 were normal. Serum immunoglobulins and serum and urine protein electrophoresis were normal and ruled out plasma cell disorders, including multiple myeloma. Anti-nuclear antibody (ANA) test and anti-rheumatoid factor (anti-RF) were negative. Total prostate-specific antigen (PSA) was greater than 100.000 μg/dl, which warranted prostate biopsy.

Echocardiography performed for possible infective endocarditis as the underlying cause of fever. It revealed normal left ventricular ejection fraction (60%) and normal echocardiographic findings. An abdominal ultrasonography ruled out any organomegaly. Upper gastrointestinal endoscopy was positive for superficial gastritis in antrum of the stomach. Colonoscopic findings were within normal range. Thoracoabdominal computerized tomography reported normal radiologic findings.

Positron emission tomography (PET CT) is ordered due to extremely high ESR levels and continuing fever. PET CT revealed metastatic lesions in bilateral costae. In addition, heterogenous mild increased activity was noted. Meanwhile, the prostate biopsy result was reported as prostate adenocarcinoma (stage 4).

After adequate intravenous hydration with saline, treatment with allopurinol 100 mg once a day, bicalutamide 150 mg once daily, and zoledronic acid 4 mg once in every 4 weeks was initiated. His vital signs, including body temperature, were remained in normal range during treatment. He discharged from hospital with full recovery of his symptoms, especially fever.

3 DISCUSSION

Here, we present an exceptional case with fever in whom the underlying cause was prostate cancer.

Prostate cancer is usually diagnosed when it became symptomatic with lower urinary tract symptoms.³ Symptoms due to prostate cancer usually occur when the tumor reaches enough diameter to compress urinary flow or invade nerves nearby. Poor urinary steam, however, has been reported by 10%–50% of the men in the general population.⁴ Another symptom of prostate cancer is urgency which was reported to be as high as 10%–50% in men.⁵ The patient in the present case report did not suffer any of these symptoms. However, elevated free PSA and prostate biopsy proven the diagnosis of prostate cancer in this case. PET-CT was taken before prostate biopsy for the diagnosis of fever of unknown origin in present patient. However, we know that Gallium 68 PSMA (prostate-specific membrane antigen) PET-CT is more sensitive and specific in prostate cancer patients.

Fever as a neoplastic origin of prostate cancer is a rare entity, just a few reported in the literature so far.⁶ Authors reported fever and weight loss in a patient substantially diagnosed with prostate cancer.⁷ Similarly, the patient in the present case was reported fever and weight loss. Thus, our findings were in accordance with literature knowledge.

The present case had anemia of chronic diseases along with prostate cancer. Nutritional deficiency of the factors involved in erythropoiesis, chronic inflammatory burden, and bone marrow infiltration is possible causes of anemia in a patient with prostatic malignancy.⁸ Therefore, we considered anemia of chronic disease in present case was caused by prostate cancer in the present case.

Multiple myeloma and adult still's disease were also considered in differential diagnosis in the present case. Normal serum immunoglobulin and normal serum and urine protein electrophoresis were ruled out of myeloma. Despite fever and extremely high serum ferritin levels arose a suspicion of adult still disease, lack of enlarged spleen or liver, lack of characteristic rashes, and lack of other involvements such as arthritis and myalgia were ruled out this condition as the cause of fever and weight loss in the present case. Authors reported increased ferritin levels were associated with higher total PSA and prostate cancer risk in the male population.⁹ Accordingly, the present patient with prostate cancer had high ferritin levels along with elevated free PSA levels.

Obesity has been linked with increased risk of prostate cancer in recent studies.¹⁰ However, the present case was not an obese patient and has lost 15 kg in 3 months. Early diagnosis of prostate cancer is crucial. Urine-based molecular tests, such as SelectMDx, may have diagnostic yield in patients with prostate cancer.¹¹ Recent studies reported that multiparametric magnetic resonance imaging and artificial intelligence/machine learning may have an important role in the diagnosis and prediction of treatment response in prostate cancer cases.^{12, 13} However, diagnosis was based on PET-CT findings in the present case.

4 CONCLUSION

We suggest that prostate cancer should be kept in mind in differential diagnosis of fever and weight loss in men over 50 years of age whether he is symptomatic or not. Total PSA measurement and prostatic biopsy in selected cases may provide essential diagnostic value in such patients.

AUTHOR CONTRIBUTION

HOA, BAT and EB managed the case, NK and GA performed literature research, EB and GA wrote the first draft. All authors approved the final version of the paper.