Infectious causes of cancer

Question 1

You Can Catch Cancer

Answer 1

Around 2 million cancer cases each year are caused by infectious agents. Application of existing public health methods for infection prevention, such as vaccination, safer injection practice, or antimicrobial treatments, could have a substantial effect on the future burden of cancer worldwide.

Aus & NZ 130000 cancer cases in 2008 4200 due to infection.

Question 2

Papillomaviruses Throughout History

Answer 2

•1842: Rigoni-Stern reports that nuns have much lower incidence of cervical cancer than prostitutes

Epidemiologistsworking in the early 20th century noted that cervical cancer behaved like a sexually transmitted disease. In summary:
Cervical cancer was common in femalesex workers.
It was rare innuns, except for those who had been sexually active before entering the convent. (Rigoni in 1841)
It was more common in the second wives of men whose first wives had died from cervical cancer.

Question 3

Harald zur Hausen

Answer 3

1983: Harald zur Hausen finds HPV types 16 and 18 lurking in HeLa cells and other cervical cancer cells.

Question 4

HPVs Are a Diverse Family

>75% lifetime infection risk!

Answer 4

HPV 16 & 18: 70% of cervical cancers, 85% of anal cancers, 50% of oropharyngeal cancers

HPV6 & 11: 90% of genital warts

• replaces tobacco for oral cancer cause

Question 5

HPV Prevalence and Cervical Cancer Incidence by Age

Answer 5

This graph shows HPV prevalence and cervical cancer incidence are a function of a woman’s age. A number of key observations can be made. First, the slide shows that in younger women, there is a high prevalence of HPV infection. However, as women age, the prevalence declines.

The group of women with persistent high-risk HPV infections are the population most at risk for having or developing cervical cancer.