Cancer incidence linked to poverty rate

A community's poverty rate correlates with the incidence of certain types of cancer, with tobacco- and HPV-related cancers more likely to strike poorer areas, according to a new study published Tuesday.

Researchers compared communities with the highest poverty levels to those with some of the lowest, using data that covered 42 percent of the U.S. population. In total, they analyzed nearly three million tumors diagnosed between 2005 and 2009, according to Francis Boscoe, researcher at the New York State Cancer Registry and the study's lead author.

Researchers categorized populations into groupings based on the poverty rate of the residential census tract at time of diagnosis. They found that in 32 of 39 cancer types, there was a significant association between cancer incidence and poverty, with 14 types of cancers associated with higher levels of poverty and 18 types associated with wealthier populations.

The study, published in the journal Cancer, is the most comprehensive nationwide assessment of the relationship between cancer incidence and poverty.

Cancers associated with behavioral risk factors such as tobacco, alcohol and poor diet were associated with higher levels of poverty. These include HPV- and tobacco-associated cancers such as cervix, oral, lung, esophagus and liver.

In contrast, skin, thyroid and prostate cancer are more common in wealthier communities, as those types of cancer are more likely to be picked up in individuals who have regular medical check-ups.

"Wealthier communities are more engaged with the health care system and have more frequent screenings," Boscoe said. 

Cancers that are associated with higher poverty tend to be much more lethal, according to the study.

Most health problems display a socioeconomic component, with those who are poorer having higher morbidity and mortality rates, according to the study.

"The ongoing monitoring of the relationship between socioeconomic status (SES) and health is an essential element of public health surveillance," the report said.

The role of poverty in cancer incidence, however, has traditionally been overlooked, in part because it is rarely collected by public health data systems, said Boscoe.

However, racial and ethnic disparities in cancer rates are frequently studied, but examining the role of race and ethnicity alone is limiting, Boscoe said. The study uncovered significant disparities within racial groups. 

“Even when you stratify by race, such as in the case of prostate and lung cancers, you still see differences in incidence rates even within race. So you end up having very distinct relationships by race and socioeconomic status that are different from one another in certain types of cancers,” Boscoe said.