Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which HPV strains are considered high-risk for cervical cancer?

1. 2, 6

2. 9, 14

3. 16, 18

4. 6, 11

The correct answer is: 16, 18

The strains of HPV that are classified as high-risk for cervical cancer are specifically types 16 and 18. These two strains are known to be responsible for the majority of cervical cancer cases globally, accounting for approximately 70% of all cervical cancers. The mechanism involves the viral oncogenes E6 and E7, which interfere with the host cell’s tumor suppressor proteins, leading to uncontrolled cell growth and potentially cancerous changes. In contrast, the other options include strains that are categorized as low-risk for cervical cancer. For instance, strains such as 6 and 11 are primarily associated with conditions like genital warts and low-grade cervical lesions, but they are not typically linked to the development of cervical cancer. Other strains in the remaining options may be associated with less severe forms or other types of lesions but do not have the same high-risk classification as types 16 and 18. Thus, the focus on types 16 and 18 is crucial in understanding the risk associated with HPV and its relation to cervical cancer.