Herbicides, pesticides, and industrial pollutants. You are probably familiar with these substances, and they all have one thing in common: they are all risk factors for liposarcoma, a fatty tissue tumour. Although the background of this rare type of cancer is not entirely understood, it is useful to avoid some chemicals to prevent the development of this disease.

What is liposarcoma?

Liposarcoma is a type of cancer that develops in fatty tissue. As a layer of fatty tissue covers our body, this tumour can start growing almost anywhere, but its most common occurrence is on the limbs, abdomen, and lower back area. In the majority of cases, it shows up on the thighs or the back part of the knee.

The symptoms vary based on the location of the cancer, but in general, it occurs as a steadily growing lump under the skin that causes swelling and does not go away over time. If it is on the leg or arm, it is usually painless, although it can cause pain if it presses a nerve. A person can also experience weakness in the affected limb. If this lump starts growing on the belly, it can cause abdominal pain, feeling full sooner when eating, constipation, or blood in the stool. When these symptoms occur, it is recommended to seek medical help, as it could be a developing liposarcoma.

This type of cancer is rare, and based on statistics, it only affects 1 out of 100,000 adults in the US each year. The most vulnerable group are people assigned male at birth, between the ages of 50 and 65. However, one subtype of liposarcoma, called myxoid liposarcoma, affects young people between the ages of 35 and 50. 

Liposarcoma in fatty tissue (created with BioRender). It can be seen that lumps develop on the fat cells, causing swelling.

What are the risk factors of liposarcoma?

A normally functioning cell has a regulated life cycle where it undergoes birth, functions, and then dies in a controlled way. Liposarcoma, like other cancers, starts developing when a random mutation in a fat cell’s DNA results in the cell undergoing uncontrolled division and not being able to respond to the signals of cell death. Scientists identified at least 20 genetic mutations behind liposarcoma. However, this still does not represent the whole picture, and further research is needed to understand the background of this disease.

These genetic mutations can be inherited, but they can also be triggered by different environmental factors. These factors are far from being described in their fullest, but researchers suggest that exposure to certain workplace chemicals, industrial pollutants, and radiotherapy can increase the risk of liposarcoma.

Workplace chemical and industrial pollutants as risk factors

As previously mentioned, research focusing on the environmental background of liposarcoma is limited. This is due to its general characteristic of being a rare type of cancer, its diverse background, and the difficulty of a long-term exposure assessment. Thus, the majority of the studies examine, beyond liposarcoma, soft tissue sarcoma, which is a broader category of sarcoma. Soft tissue sarcomas (STS) develop in soft tissues (the tissues that surround the bones), such as tendons, muscles, or fat. They are also considered to be rare, as they represent less than 1% of all adult cancer cases.¹ Based on research findings, the risk of this cancer can be reduced by avoiding certain workplace chemicals and industrial pollutants.²

Workplace chemicals

Phenoxy herbicides

Phenoxy herbicides are a commonly used family of herbicides in agriculture, forestry, parks, and domestic gardens. These chemicals mimic the function of a plant hormone called auxin, which causes a rapid and abnormal growth in weeds, eventually leading to their deaths, but other plants are left relatively unharmed. Direct contact with these chemicals can cause skin and eye irritation, and studies have proven their hazardous effect of causing cancer.³ They have been in commercial use since the 1940s, but their regulations changed in the 1970s, when one of their compounds got banned in the EU and the US. Their environmental and health effects are constantly monitored, and current research suggests that regular exposure to phenoxy herbicides can increase the risk of STS by less than 2%.^2,4

Chlorophenols

Chlorophenols are a broad group of chemical compounds commonly found in different industries as an essential raw chemical. They are common components of pesticides and preservatives of leather, textile, and wood. Chlorophenols can also be found in pharmaceutical production, disinfectants, or dyeing products. Their use is heavily regulated due to their hazardous effects on human health, including skin and eye irritation, nervous system, and kidney and liver problems. They also pose a harm to the natural habitats, especially aquatic environments. In relation to liposarcoma, it is said to elevate the risk of STS by less than 2%.^2,5 

Vinyl chloride monomer

Vinyl chloride monomer (VCM) is a colourless, flammable, and unstable gas, which has a mild, sweet odour. It is essential in the manufacture of polyvinyl chloride (PVC), which is a crucial component in a range of products, such as plastics, packaging materials, and flooring. Inhaling VCM gas can cause headaches, dizziness, sleepiness, and unconsciousness. Upon contact with skin, it can cause frostbite symptoms, such as numbness, redness, and blisters. It is proven that VCM increases the risk of angiosarcoma in the liver,⁶ and it is also suggested that it can increase the chance of STS by around 2.2%. However, more research is needed to confirm this risk factor.²

Industrial pollutants

Dioxins

Dioxins belong to a chemical compound family that are mainly byproducts of industrial processes, such as metal smelting, chlorine bleaching of paper pulp, and the manufacture of certain herbicides and pesticides. They can escape into the environment during solid waste and hospital waste incineration. Although they are mainly a result of human actions, they can also be released during volcanic eruptions and forest fires. They are highly toxic to the environment and human health and are known for their chemical stability, meaning that they are able to remain in the environment for decades. They can be absorbed into fatty tissues and accumulate in the food chain, where they can be found in dairy products, meat, fish, and shellfish. Their short-term exposure can cause skin lesions and liver damage, whereas long-term exposure causes problems in the immune, endocrine, and reproductive systems. It represents one of the highest chemical risk factors of STS, as it increases the risk of STS by an average of 2.5%^2,7.

Polychlorinated biphenyls (PCBs)

Polychlorinated biphenyls represent hundreds of chemical compounds that share the main characteristics of chemical stability, heat resistance, high boiling point, and electrical insulating properties. They have been widely used in electrical, heat transfer, and hydraulic equipment since the 1930s, but they became heavily regulated or even banned in the EU and the US. They have similar properties to dioxins, as they remain in the environment for decades, are absorbed into fatty tissues, and accumulate in the food chain. Upon contact with PCBs, skin rashes and possibly liver damage occur. Although their use has decreased in the last 50 years, illegal or improper dumping of PCBs or unregulated waste incinerators still poses risks. PCBs are said to increase the risk of STS by 1-2%.⁸

Radiation therapy as a risk factor

Ionising radiation is one of the main risks in the development of soft tissue sarcomas; however, encountering such a high-risk radiation source is not common. The majority of people experience it during radiation therapy for cancer treatment. A study shows that childhood cancer survivors who went through radiotherapy had 16 times higher STS risk than those who did not, and this increases with higher dosage level.⁹ In adults, it is well-established that breast cancer patients who received radiotherapy had a higher risk of developing STS¹⁰.

Research also found that the risk increases over time after the diagnosis of the first cancer (22% at 1-4 years, 120% at 15+ years), and it also depends on the age of the patients: younger people have a higher chance of developing STS in the future (83% at age 60-79, 432% at age 20-39). Evidence shows that these also depend on the location of the primary cancer.¹¹

Environmental risk factors in liposarcoma (created with BioRender)

Which occupations are the most exposed?

The table below summarises different occupations that are exposed to chemicals associated with STS risk.

Occupations with a high risk of liposarcoma (created with BioRender)

Summary

Liposarcoma is a rare type of cancer that develops from the fatty tissues as a steadily growing lump under the skin. Research suggests that 20 possible genetic mutations can lead to it, which can be inherited or triggered by environmental factors. These environmental factors include workplace chemicals, such as phenoxy herbicides, chlorophenols, and vinyl chloride monomer, as well as industrial pollutants, like dioxins and polychlorinated biphenyls. The occupations with the highest exposure to these chemicals are woodworkers, industry workers, gardeners and farmers, meat workers, and railroad and construction workers. Hence, it is essential that they follow the regulations and wear the required protective equipment, such as glasses, gloves, and masks, even if it may feel uncomfortable. Not only do they reduce the risk of liposarcoma or other soft tissue sarcomas, but they also have other hazardous effects on health.

FAQs

What are the symptoms of liposarcoma?

Because liposarcoma develops in fatty tissues, its symptoms can vary. However, the main characteristic is a steadily growing lump on your limbs or the upper part of your body.

How common is liposarcoma?

Liposarcoma is very rare and mainly affects people of older age.

Which chemicals can increase the chance of liposarcoma?

Workplace chemicals (such as phenoxy herbicides, chlorophenols, and vinyl chloride monomer), as well as industrial pollutants (like dioxins and polychlorinated biphenyls), can lead to liposarcoma. However, current research is focused on the broader category, which is soft tissue sarcoma.

Which occupations have the risk of developing liposarcoma?

As occupational hazards, the most exposed are woodworkers, industry workers, gardeners, farmers, meat workers, and railroad and construction workers.

How can I avoid exposure to these harmful chemicals?

Follow the regulations and always wear protective equipment, such as glasses and masks, even when it feels uncomfortable, to reduce the risk of developing liposarcoma and other soft tissue sarcomas.