This New Year’s Day brings us into the Year of the Dragon, and marks my second-year anniversary from the end of chemotherapy. One more year and my risk of recurrence drops considerably. But while I think of my great good fortune, in the past month, I have learned of four friends or acquaintances who are now facing a cancer diagnosis for the first time, a somber and increasingly common experience.
In my last post, I summarized global cancer statistics and trends. This time, I’m considering my own proverbial back yard. The data you see here relate to cancer in the United States and come from Cancer Facts & Figures 2011, published by the American Cancer Society (ACS).
According to the authors of this booklet, “[t]wo major classes of factors influence the incidence of cancer: hereditary factors and acquired (environmental) factors… Environmental (as opposed to hereditary) factors account for an estimated 75%-80% of cancer cases and deaths in the US.” This percentage breaks down as follows:
- Exposure to carcinogens in occupational, community and other settings – 6%
- Tobacco smoking – 30%
- Poor nutrition, lack of physical activity, and obesity – 35%
Add up these numbers (71%) and you’ll see that the specific environmental causes of a good number of cases are still unexplained. (BPA? Pesticides? All those chemicals we ingest or pour into our water sources every year?)
The booklet goes on to note that “even a small percentage of cancers can represent many deaths: 6%…corresponds to approximately 34,320 deaths.” And “the burden of exposure to occupational and environmental carcinogens is borne disproportionately by lower-income workers and communities, contributing to disparities in the cancer burden across the population.” The ACS figures that, if racial and economic disparities in the United States were eliminated, there would be 37% fewer deaths from cancer, leading the agency to conclude that poverty is a carcinogen.
Elsewhere in the book, the authors note that “questions remain about the role of exposures to certain classes of chemicals (such as hormonally active agents) during critical periods of human development.” Answers to these questions might eventually explain why birth control pills have not been conclusively tied to cancer but hormone-replacement therapy after menopause has.
Here are some interesting data on the most prevalent cancers – lung, prostate, and breast:
Lung cancer alone is responsible for 27% of all cancer deaths, and is the number 1 cause of cancer deaths for both men and women. The ACS notes that, “[s]ince 1987, more women have died each year from lung cancer than from breast cancer.” And yet, we don’t see nearly the same amount of energy put toward races to cure lung cancer as we do for breast cancer. (See more about this disparity here).
This is just one of many examples of how data about health and disease is skewed by marketing forces. Breasts and the color pink are palatable (though honestly, I’m tired of women being defined by their breasts for any reason and pink being chosen as the color to represent women). Apparently, lungs and their color – pearl – are not so sexy. Yes, more women are diagnosed with breast cancer, but more die of lung cancer.
Prostate cancer is the second leading cause of cancer deaths in men. Anticipated new cases for 2011 total 240,890, with 33,720 deaths. African-American men and Jamaican men of African descent have the highest rates of prostate cancer in the world, and the disease is more prevalent in North America and northwestern Europe, less so in South America and Asia.
Breast cancer is the second leading cause of cancer deaths in women. For 2011, the ACS estimates 230,480 new cases of invasive breast cancer among women, 2140 in men. This number does NOT include the type referred to as DCIS, which is not usually invasive, and has been referred to as the “good” breast cancer.
Notice the statistics: In 2011, more men will have been diagnosed with prostate cancer than women with breast cancer, but fewer men die of prostate cancer.
The list of risk factors for breast cancer contains the usual suspects (obesity, physical inactivity, and alcohol, which acts like an estrogen in the body). But I see that the ACS is finally listing dense breast tissue as a risk factor along with high bone mineral density and a breast irregularity called hyperplasia (especially atypical hyperplasia). They also note that there is some evidence that women who work night shifts seem to have an increased risk of breast cancer.
But as always with breast, and perhaps other cancers, there is a caveat. These factors relate primarily to the hormone-driven breast cancers (ER+, PR+ Her/2-, or any combination of these). Those of us dealing with the triple-negative type might have an entirely different set of risk factors that has not yet been determined. I’ve seen preliminary reports that a too-low body mass index and having had children at all are risks for triple-negative disease.
By state, the incidence of breast cancer pretty much follows the trend of national totals for all types of cancer, with California and Florida at the top of the list, followed by New York and Texas. Here in Washington, the projected number of new cases of breast cancer for 2011 is 5,630. In my native Ohio, it’s 8,970. The number of deaths from breast cancer are also similar, led by California and Florida, then Texas and New York. In Washington, that number is 800; in Ohio, it’s 1730.
In the flurry of all these numbers, don’t get confused. The numbers by state may reflect only that one state has a higher population than another, not that there are necessarily more risks tied to location. The number of new cases for each state is pretty high, but the number of deaths is significantly lower, which only means there are many, many survivors of breast cancer out there.
Certainly we know by now how bad smoking can be for us, but here are some interesting details about the exposure to second-hand smoke: “Each year, about 3,400 nonsmoking adults die of lung cancer as a result of breathing SHS [secondhand smoke]” and “SHS causes an estimated 46,000 deaths from heart disease in people who are not current smokers.” Perhaps this is because SHS contains about 7,000 chemicals, “at least 69 of which cause cancer.”
In my home state of Ohio, the overall estimated number of new cancer cases for 2011 is 65,060. In my adopted state of Washington, that number is 35, 360. Quite a difference, but some of that has to do with population (Ohio has about 11,542,645 residents while Washington has 6,664,195). The state with the highest overall estimate is California (with 163,480 estimated new cases), followed by Florida (113,400) and Texas (105,000). Wyoming has the smallest number (2,680).
There is much more information and data in the ACS booklet, so much as to be overwhelming. To make better sense of the numbers, here’s a wider perspective:
- Heart disease is still the most common cause of death in the United States, with cancer second. Cancer has killed about 499,564 people so far this year, but heart disease has killed 593,819.
- About 1500 people die of cancer each day, compared to about 2200 for heart disease.
- As of January 2007, the estimated number of cancer survivors in the United States is 11.7 million, which means about 4% of the population has had the cancer experience.
According to the Stand Up to Cancer organization, 1 out of every 3 women and 1 out of every 2 men are at risk of developing cancer in their lifetime. I guess I’m one of those who is “experienced.” Now, I’m looking to that dragon to protect me.