From the Guidelines
Pruritus in gastric cancer patients is often multifactorial, resulting from a combination of factors including paraneoplastic syndromes, skin metastases, and side effects of cancer treatment 1.
Possible Causes
- Paraneoplastic syndromes: can be associated with the release of substances such as histamine and gastrin-releasing peptide, leading to pruritus 1.
- Skin metastases: can cause pruritus due to the direct involvement of the skin by the tumor.
- Cancer treatment: certain chemotherapy agents, such as epidermal growth factor inhibitors, can cause pruritus as a side effect 1.
Treatment-Related Pruritus
Pruritus can also be a side effect of biological therapies, which are commonly used in oncology, with a recent meta-analysis of 33 RCTs concluding that pruritus was a significant side-effect of cancer treatment with this class of agent 1. Additionally, chemotherapy agents such as capecitabine and oxaliplatin can cause skin rash and pruritus as a side effect. In some cases, the itchy spots may be related to liver dysfunction, which can occur in advanced gastric cancer, leading to elevated bile salts and subsequent pruritus. It is essential to ask oncology patients receiving biological therapies about pruritus on review and to consider modification or discontinuation of medications if pruritus occurs 1.
From the Research
Causes of Pruritus in Gastric Cancer Patients
- Pruritus is described as a paraneoplastic sign in patients with gastric cancer 2
- Cutaneous metastasis from gastric cancer can cause pruritus, although it is a rare entity 3, 4, 5, 6
- Paraneoplastic dermatomyositis is a distinct clinical variant of dermatomyositis that can occur in patients with gastric cancer, and pruritus is a common symptom of this condition 2
- The exact mechanism of pruritus in gastric cancer patients is not well understood, but it may be related to the release of pruritogenic substances by the tumor or the host's immune response to the tumor 2
Clinical Manifestations of Cutaneous Metastasis
- Cutaneous metastasis from gastric cancer can manifest as nodular skin lesions, erysipelas-like skin lesions, or other types of skin lesions 4, 5, 6
- The most common location of cutaneous metastasis is the thoracoabdominal wall 4
- Cutaneous metastasis can be the first sign of a clinically silent visceral cancer or represent recurrence of an internal malignancy 5
Diagnosis and Treatment of Cutaneous Metastasis
- Diagnosis of cutaneous metastasis is often delayed due to its rarity and nonspecific clinical presentation 3, 4
- Skin biopsy is essential for diagnosing cutaneous metastasis 3, 4, 5, 6
- Treatment of cutaneous metastasis depends on the extent of the disease and the patient's overall condition, and may include systemic chemotherapy, radical surgery, or palliative surgical excision 4, 6