Chapter 37, Problem 1DAA

Cervical Cancer Incidence In HPV-Positive Women In 2003, Michelle Khan and her coworkers published their findings on a 10-year study in which they followed cervical cancer incidence and HPV status in 20,514 women. All women who participated in the study were free of cervical cancer when the test began. Pap tests were taken at regular intervals, and the researchers used a DMA probe hybridization test (Section 15.3) to detect specific types of HPV in the women's cervical cells.

The results are shown in FIGURE 37.26 as a graph of the incidence rate of cervical cancer by HPV type. HPV- positive women are often infected by more than one type, so the data were sorted into groups based on the women's HPV status ranked by type: either positive for HPV16; or negative for HPV16 and positive for HPV18; or negative for HPV16 and HPV18 and positive for any other cancer-causing HPV; or negative for all cancer-causing HPV.

Follow-up time (months)

FIGURE 37.26 Cumulative incidence rate of cervical cancer correlated with HPV status in, 20,514 women aged 16 years and cider.

The data were grouped as follows:

● HPV16 positive

○ HFV16 negative and HPV18 positive

▼ All other cancer-causing HPV Types combined

∇ No cancer-causing HPV type was detected.

1. At 110 months into the study, what percentage of women who were not infected with any type of cancer-causing HPV had cervical cancer? What percentage of women who were infected with HPV16 also had cervical cancer?