01. Laryngeal Cancer
Laryngeal cancer forms in the larynx commonly referred to as the voice box or Adam’s apple. It is considered a rare cancer, with around 12,000 – 13,000 cases each year. Typical risk factors for this type of cancer include smoking, moderate alcohol consumption, diet, and workplace exposures to toxins like asbestos.
Though there are some studies that dispute a causal relationship, the National Institutes of Health review of many studies around select asbestos cancers concluded that there is sufficient evidence available to infer laryngeal cancer may be caused by asbestos exposure. In observing these studies, the committee concluded that exposure generally increased the risk of developing this cancer by around 40%. Various studies found the risk for laryngeal cancer increased significantly when exposed to asbestos, sometimes more than doubling the risk.
02. Ovarian Cancer
Ovarian cancer first develops in the ovaries and can spread to other parts of the body. While the incidence rate has been decreasing lately, it still ranks as fifth for the most cancer deaths in women. The cause of ovarian cancer is not well understood in every case, though researchers have found connections with genetic mutations like BRCA1, family history, age and asbestos exposure.
Studies as early as the 1970s have shown asbestos’ link to ovarian cancer. A report from the International Agency for Research on Cancer analyzed various studies around asbestos exposure, and determined asbestos could significantly increase risk of ovarian cancer. Though many of these cancers have been observed from the lense of occupational exposure, ovarian cancer may also be a result of exposure to talcum powder. Many talcum powder products have been revealed to be contaminated with asbestos, which has contributed to women developing ovarian cancer years after use. Exposure to asbestos-contaminated talcum powder has also been linked to some mesothelioma cases.
03. Esophageal Cancer
Esophageal cancer generally starts in the inner laying of the esophagus and spreads outward. It is a more rare cancer overall and is generally more common in men than women. Researchers have identified a number of risk factors for developing this cancer including patient characteristics like age and other health conditions like reflux. Smoking and alcohol consumption, as well as toxic exposures, have also been linked to esophagus cancer.
A recent study that spanned 10 years found workers who experienced occupational exposure to the mineral had a higher risk factor of developing esophageal cancer, especially those who experienced prolonged exposure. There is debate over whether asbestos exposure has a clear causal effect with esophageal cancer, however.
04. Inconclusive Link to Asbestos
Cancers with Inconclusive Links to Asbestos
There have been many studies around the potential link of asbestos to a number of cancers. For some of these, studies have shown mixed results where researchers were able to confirm a link with asbestos or found no strong connection. More research is necessary to better determine the connections between these cancers and asbestos, but all of them have shown the potential for a direct link.
It is estimated that 1 out of 8 women will develop breast cancer at some point in their lives. Though much less common in men, the American Cancer Society estimated over 2,500 new cases in 2018. Many cases of breast cancer are linked to genetic mutations, though researchers have also found links to other risk factors including asbestos exposure.
There have been many studies around asbestos and breast cancer, but there is little evidence showing exposure has a significant impact on the risk of developing this cancer. One study observed over 2,500 women exposed to asbestos in Australia from 1943 to 1992. Though those exposed faced a higher risk of cervical and ovarian cancer than the general population, the researchers found the risks for breast cancer to remain the same. Other similar studies in England around asbestos factory workers, however, found that exposure could significantly increase the risk for breast cancer. Despite some studies suggesting a possible causal link, there is not enough evidence to suggest clear causation between asbestos and breast cancer.
Also known as colorectal cancer, colon cancer develops in the colon or the rectum and is the third most common cancer in the United States. Research has found a number of risk factors for colorectal cancer, like genetics, diet and age, but in many cases, it can be difficult to determine the exact cause. Colon cancer has been linked to asbestos exposure in several studies, with many of these studies specifically investigating occupational exposure.
One study conducted from 1984 to 2004 evaluated 3,897 participants who had been exposed to asbestos at work. Keeping other factors in mind like smoking, the researchers concluded that exposure did increase the risk of developing colorectal cancer. During the time of the study, there were 85 diagnoses of colorectal cancer among the participants, with some participants facing a 54% increased risk or higher of colon cancer. However, other similar studies have found no causal evidence between exposure to asbestos and colon cancer.
After evaluating many of these studies, a scientific review through the National Institutes of Health stated that the evidence found thus far is suggestive but not sufficient to imply a definitive relationship between asbestos exposure and the development of colorectal cancer.
Kidney cancer develops in the kidneys, organs in the abdomen that filter and remove waste from the blood. The most common form of kidney cancer is renal cell carcinoma, accounting for about 9 out of 10 cases. The cause of kidney cancer is unclear, though doctors have noted age, high blood pressure, obesity and other kidney conditions can contribute to a higher risk of disease.
There have been few studies around kidney cancer and asbestos exposure. A recent study observed a retired asbestos worker who first showed symptoms of renal cell carcinoma. The worker underwent surgery to remove the tumors but was admitted again the following year for abdominal pain. Doctors then diagnosed him with biphasic mesothelioma. This was only the second reported case connecting renal cell carcinoma and mesothelioma but suggests that asbestos exposure could increase the risk for kidney cancer.
Pancreatic cancer is a type of gastrointestinal cancer that develops in the pancreas, an organ behind the lower part of the stomach. Smoking, diet and weight are some of the most common risks for developing pancreatic cancer. It is also more common among people with diabetes and other health conditions like pancreatitis or various stomach problems.
Pancreatic cancer has also been linked to workplace exposures to different toxins, including asbestos. Some studies have investigated the link between ingested asbestos, whether through drinking water or workplace exposure, and a variety of gastrointestinal cancers. One of these studies followed an instance of asbestos-contaminated water in Woodstock, New York in the 1980s. Researchers observed residents through 1998 for symptoms of cancer, finding an elevated risk for pancreatic and gastrointestinal cancers particularly among men. They documented 10 cases of pancreatic cancer during this time, as well as other gastrointestinal cancers. Despite this case and similar studies, overall researchers note that particularly with asbestos in drinking water, it’s difficult to understand the threshold for the amount of exposure and the risk of cancer.
Pharyngeal cancer, sometimes referred to as throat cancer, develops in the pharynx, a hollow tube that runs from the nose to the top of the esophagus. Like other head and neck cancers, some of the common risk factors are age, smoking and moderate to heavy alcohol consumption. People who have Epstein-Barr or human papillomavirus (HPV) also have an increased risk.
There have also been studies around the risk of pharyngeal cancer when exposed to asbestos, though the link is still a bit controversial. Many of these studies only looked at small groups of patients with occupational exposure to asbestos. Even though a majority of the studies showed an increased risk from asbestos, the data wasn’t strong enough overall to make any clear conclusions. The National Institutes of Health found that evidence is suggestive of the link, but still not substantial enough to definitively say asbestos causes pharyngeal cancer.
Prostate cancer is the most common cancer in men, with about 1 out of 9 men diagnosed in their lifetime. The cause of prostate cancer isn’t well understood. Age, obesity and a family history of prostate cancer all contribute to an increased risk.
Several studies have implicated asbestos exposure in the development of prostate cancer. One involved asbestos miners from the now-defunct town of Wittenoom in the state of Western Australia, which was a primary source of deadly crocidolite (blue asbestos) for decades. Researchers noted that those who lived in and around Wittenoom suffered from a higher rate of prostate cancer than the general population. Another Finnish study published in 2003 observed over 20,000 workers who had been exposed to asbestos over a period of eight years. They found elevated rates of prostate cancer among those exposed compared to the general population. Still, researchers aren’t certain of a definite causal relationship.
Stomach or gastric cancer is a type of gastrointestinal cancer that develops in the lining of the stomach. While the number of cases of stomach cancer has remained rather steady since 2005 at about 26,000 each year, the number of deaths has decreased significantly. Diet, tobacco use, age and gender are some of the most common risk factors for developing this cancer.
Some studies have explored the possibility of asbestos ingestion or inhalation as a cause of stomach cancer. Much of these studies have conflicting data around this link. One study that did show a clear connection came from Norway in 2005. Researchers studied a group of over 700 lighthouse workers who had ingested asbestos from contaminated drinking water. They found the risk of stomach cancer increased for all of those exposed, as well as other gastrointestinal cancers. Like many of these other cancers, however, researchers say the evidence so far is more suggestive than sufficient for a clear causal relationship.