Prostate cancer solitary metastasis to anal canal: case report and review of literature

Prostate cancer invading rectal serosa and anal sphincter treated with definitive radiation therapy: Case report and review of the literature

ABSTRACT

Despite anatomical proximity, prostatic adenocarcinoma with rectal invasion is rare. We describe a case of prostate cancer invading the anal sphincter, treated with radiation therapy (RT). A 78-year-old patient underwent definitive radiotherapy in 2018 because of poorly differentiated adenocarcinoma, Gleason 4 + 3 (7). The initial stage was mrT4N0 on magnetic resonance imaging (MRI) images. The pre-treatment prostate-specific antigen level was 142 ng/mL, and the patient was subjected to androgen deprivation therapy. RT was performed using volumetric modulated arc therapy (VMAT) and a dose of 76 Gy in 38 fractions. After 2 months, MRI showed a complete response. During RT, toxicity was limited to mild gastro-intestinal and urologic symptoms. This report is the first to describe prostate cancer invasion of the anal sphincter and to extend to that condition the use of RT - already regarded as a useful treatment option for inoperable locally advanced high-risk prostate cancer (PC). This study suggests that VMAT can be a safe and effective treatment option for locally advanced high-risk PC patients.

Unexpected and Rare Sites of Metastasis in Oncologic Patients

Case studies of rare oncologic metastases are an important source of clinical data for health care professionals and researchers. While infrequent, the knowledge base and clinical recommendations derived from such cases aid in advancements in the field. As such, we aim to add five cases to the growing body of literature. The first two male patients, aged 69 and 73, were diagnosed with colon adenocarcinoma, suspected to be a second primary prostate carcinoma, following positron emission tomography-computer tomography (PET-CT). This suspicion was ruled out by prostatectomy and histopathological investigations, which instead found adenocarcinoma of colonic origin. The next two male patients, ages 63 and 68, were diagnosed, respectively, with metastatic pancreatic adenocarcinoma with cardiac metastases and metastatic melanoma with distant metastases to the pancreas. The final patient was a 73-year-old male diagnosed with metastatic breast cancer after a radiological investigation of suspected renal cell carcinoma.

Molecular predictors of metastasis in patients with prostate cancer

INTRODUCTION

Prostate cancer is a serious threat to the health of older adults worldwide. The quality of life and survival time of patients sharply decline once metastasis occurs. Thus, early screening for prostate cancer is very advanced in developed countries. The detection methods used include Prostate-specific antigen (PSA) detection and digital rectal examination. However, the lack of universal access to early screening in some developing countries has resulted in an increased number of patients presenting with metastatic prostate cancer. In addition, the treatment methods for metastatic and localized prostate cancer are considerably different. In many patients, early-stage prostate cancer cells often metastasize due to delayed observation, negative PSA results, and delay in treatment time. Therefore, the identification of patients who are prone to metastasis is important for future clinical studies.

AREAS COVERED

this review introduced a large number of predictive molecules related to prostate cancer metastasis. These molecules involve the mutation and regulation of tumor cell genes, changes in the tumor microenvironment, and the liquid biopsy.

EXPERT OPINION

In next decade, PSMA PET/CT and liquid biopsy will be the excellent predicting tools, while ¹⁷⁷ Lu- PSMA-RLT will be showed excellent anti-tumor efficacy in mPCa patients.

An unusual delayed rectal metastasis from prostate cancer masquerading as primary rectal cancer

Introduction and importance

Rectal metastasis of prostate cancer origin is exceedingly rare. Its clinical presentation, endoscopic morphology, and histopathology are similar to primary rectal cancer. Misdiagnosis may lead to inappropriate treatment.

Case presentation

We report a case of a gentleman in his 80's with a history of treated prostate cancer T3aN0M0 with radical prostatectomy sixteen years ago. He presented with one-year complaints of altered bowel habits and weight loss. Physical and rectal examination was unremarkable. Colonoscopy manifested some inflammatory changes in the rectum. The pelvis magnetic resonance imaging (MRI) showed an abnormal posterior rectal wall thickening 2 cm above the anal canal. Biopsy confirmed poorly differentiated adenocarcinoma of prostate origin. The staging workup was negative for other distant metastasis. After a multidisciplinary decision, the patient was started on androgen deprivation therapy and given palliative radiotherapy to the rectum. Six weeks later, the patient was stable with mild radiation proctitis.

Clinical discussion

Management of rectal metastasis varies depending on the patient's choice, the extent of metastatic burden, symptoms, age, life expectancy, quality of life and comorbidities. While surgery remains the standard of care, other option including radiotherapy, hormonal therapy and chemotherapy has been documented in the literature with survival of few weeks to 2 years.

Conclusion

Delayed rectal metastasis of prostate cancer after radical prostatectomy is a rare entity. Its clinical presentation and endoscopic and histopathological findings of rectal metastasis are similar to primary colorectal cancer, making diagnosis more demanding.

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Rectum is a rare isolated site of metastasis from prostate cancer.

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Symptoms and endoscopic morphology of rectal metastasis are similar to primary rectal cancer.

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Prostate-specific antigen is not always raised in rectal metastasis.

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Emergent lower gastrointestinal symptoms in patients with a history of prostate cancer warrants a multidisciplinary approach to reach an accurate diagnosis and prompt treatment.

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Management of rectal metastasis depends on patient desire, the severity of symptoms, age, quality of life, life expectancy and comorbidities.

Isolated Rectal Metastases from Locally Advanced Carcinoma Prostate Detected by 18F-PSMA-1007 PET/CT

Rectal involvement by prostate carcinoma is rare and isolated rectal metastases are even rarer with only a few cases having been reported in the literature. In our knowledge, no case of isolated rectal metastases diagnosed on prostate specific membrane antigen positron emission tomography/computed tomography has been reported to date. We present a case of a 66-year-old patient who presented with rectal bleeding and passage of urine from anal region and was diagnosed with carcinoma prostate infiltrating the rectum along with solitary rectal metastases.