Hamartomatous polyps: Diagnosis, surveillance, and management

Table 4 Studies investigating the malignancy risk associated with phosphatase and tensin homolog mutation

Ref.	N	Location	Outcome
Tan et al[87]	3399	North America, Europe, and Asia	Patient with PTEN mutations possess a lifetime breast cancer risk of 85%, thyroid cancer risk of 35%, renal cell carcinoma of 35%, endometrial cancer risk of 28%, colorectal cancer risk of 9%, and melanoma risk of 6%
Fackenthal et al[88]	2	United States	There is an increased risk of male breast cancer in patient with PTEN mutations and CS
Harach et al[89]	11	Argentina	Patients with CS have increased likelihood of developing benign thyroid lesions, with increased risk of malignant transformation
Ngeow et al[90]	2723	United States	CS and CS-like phenotypes possess standardized incidence rate for thyroid cancer of 72%, particularly follicular thyroid cancer
Heald et al[91]	127	North America and Europe	PTEN mutations are associated with early-onset (age < 50) colorectal malignancy; routine colonoscopy should be encouraged

PTEN: Phosphatase and tensin homolog; CS: Cowden syndrome.