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It will get worse. How can we correct this challenge?

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Tuesday, July 30, 2024

New Transparent AI Predicts Breast Cancer 5 Years Out

A new way of using artificial intelligence (AI) can predict breast cancer 5 years in advance with impressive accuracy — and unlike previous AI models, we know how this one works.

The new AI system, called AsymMirai, simplifies previous models by solely comparing differences between right and left breasts to predict risk. It could potentially save lives, prevent unnecessary testing, and save the healthcare system money, its creators say.

"With traditional AI, you ask it a question and it spits out an answer, but no one really knows how it makes its decisions. It's a black box," said Jon Donnelly, a PhD student in the Department of Computer Science at Duke University, Durham, North Carolina, and first author on a new paper in Radiology describing the model.

"With our approach, people know how the algorithm comes up with its output so they can fact-check it and trust it," he said.

One in eight women will develop invasive breast cancer, and 1 in 39 will die from it. Mammograms miss about 20% of breast cancers. (The shortcomings of genetic screening and mammograms received extra attention recently when actress Olivia Munn disclosed that she'd been treated for an aggressive form of breast cancer despite a normal mammogram and a negative genetic test.)

The model could help doctors bring the often-abstract idea of AI to the bedside in a meaningful way, said radiologist Vivianne Freitas, MD, an assistant professor of medical imaging at the University of Toronto, Canada.

"This marks a new chapter in the field of AI," said Freitas, who authored an editorial lauding the new paper. "It makes AI more tangible and understandable, thereby improving its potential for acceptance."

AI as a Second Set of Eyes

Donnelly described AsymMirai as a simpler, more transparent, and easier-to-use version of Mirai, a breakthrough AI model which made headlines in 2021 with its promise to determine with unprecedented accuracy whether a patient is likely to get breast cancer within the next 5 years.

Mirai identified up to twice as many future cancer diagnoses as the conventional risk calculator Tyrer-Cuzick. It also maintained accuracy across a diverse set of patients — a notable plus for two fields (AI and healthcare) notorious for delivering poorer results for minorities.

Tyrer-Cuzick and other lower-tech risk calculators use personal and family history to statistically calculate risk. Mirai, on the other hand, analyzes countless bits of raw data embedded in a mammogram to decipher patterns a radiologist's eyes may not catch. Four images, including two angles from each breast, are fed into the model, which produces a score between 0 and 1 to indicate the person's risk of getting breast cancer in 1, 3, or 5 years.

But even Mirai's creators have conceded they didn't know exactly how it arrives at that score — a fact that has fueled hesitancy among clinicians.

Study coauthor Fides Schwartz, MD, a radiologist at Brigham and Women's Hospital, Boston, Massachusetts, said researchers were able to crack the code on Mirai's "black box," finding that its scores were largely determined by assessing subtle differences between right breast tissue and left breast tissue.

Knowing this, the research team simplified the model to predict risk based solely on "local bilateral dissimilarity." AsymMirai was born.

The team then used AsymMirai to look back at > 200,000 mammograms from nearly 82,000 patients. They found it worked nearly as well as its predecessor, assigning a higher risk to those who would go on to develop cancer 66% of the time (vs Mirai's 71%). In patients where it noticed the same asymmetry multiple years in a row, it worked even better, with an 88% chance of giving people who would develop cancer later a higher score than those who would not.

"We found that we can, with surprisingly high accuracy, predict whether a woman will develop cancer in the next 1-5 years based solely on localized differences between her left and right breast tissue," said Donnelly.

Schwartz imagines a day when radiologists could use the model to help develop personalized screening strategies for patients. Doctors might advise those with higher scores to get screened more often than guidelines suggest, supplement mammograms with an MRI, and keep a close watch on trouble spots identified by AI.

"For people with really low risk, on the other hand, maybe we can save them an annual exam that's not super pleasant and might not be necessary," said Schwartz.

Cautious Optimism

Robert Smith, PhD, senior vice president of early cancer detection science at the American Cancer Society, noted that AI has been used for decades to try to reduce radiologists' workload and improve diagnoses.

"But AI just never really lived up to its fullest potential," Smith said, "quite often because it was being used as a crutch by inexperienced radiologists who, instead of interpreting the mammogram and then seeing what AI had to say ended up letting AI do most of the work which, frankly, just wasn't that accurate."

He's hopeful that newer, more sophisticated iterations of AI medical imaging platforms (roughly 18-20 models are in development) can ultimately save women's lives, particularly in areas where radiologists are in short supply.

But he believes it will be a long time before doctors, or their patients, are willing to risk postponing a mammogram based on an algorithm.

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How to avoid forever chemicals in food, drinking water - The Washington Post

How can I avoid eating food with ‘forever’ chemicals?



Across the country, states are banning forever chemicals from consumer products, and some companies are promising to phase out the use of the compounds.

But what are we supposed to do in the meantime?

“Forever chemicals,” or PFAS, which stands for per- and polyfluoroalkyl substances, are known for their persistent ability to remain in nature — and the body — for years. Certain PFAS have been associated with serious health effects, including infertility, high blood pressure and some cancers, according to the Food and Drug Administration.

Cindy Luppi, the national field director for Clean Water Action, said “it’s very hard” for people to avoid products with PFAS.

“For the average consumer, there’s no way to avoid it,” said Graham Peaslee, a physics professor at the University of Notre Dame. “But, you can do some smart things.”We spoke to PFAS experts about the steps you can take to minimize exposure from the foods you eat. Here’s their advice.


States take matters into their own hands to ban ‘forever chemicals’

Cut back on fast food (and greasy wrappers)

Grease-resistant fast-food packaging that keeps oil and meat juices from spilling on your clothes often also contains oil-resistant PFAS. This includes the paper wrappers, boxes, and other containers used to serve burgers, fries, and salads from fast-food chains.

Your risk of exposure to PFAS depends on the “contact time” — the time the food has spent inside of that plastic bag or paper wrapper, said Jamie DeWitt, professor of pharmacology and toxicology at East Carolina University.


Last year, Consumer Reports tested more than 100 food packages and reported higher levels of PFAS in wraps, trays, and bags from Burger King, McDonald’s, Chick-fil-A, and Cava, among others.  

                         




The dangers from PFAs are how they accumulate and transfer from food source to food source, not only by people being exposed directly to industrial contaminants.  PFAS (per- and polyfluoroalkyl substances) are a group of synthetic chemicals that are harmful to human health and the environment. Here are some key points about the harmful effects of PFAS:


Environmental persistence:
PFAS are highly persistent in the environment, meaning they do not easily break down and can accumulate over time. They can contaminate soil, groundwater, and surface water.

Bioaccumulation: PFAS can bioaccumulate in the bodies of living organisms, including humans, and can be passed up the food chain.

Toxicity: Certain PFAS have been linked to a variety of health problems, including:
Elevated cholesterol levels
Decreased vaccine response in children
Increased risk of thyroid disease
Decreased fertility and pregnancy complications
Increased risk of certain cancers, such as kidney and testicular cancer
Widespread exposure: PFAS are found in a wide range of consumer products, such as nonstick cookware, food packaging, stain-resistant fabrics, and firefighting foams. This leads to widespread human exposure through multiple routes, including ingestion, inhalation, and dermal absorption.
Regulatory challenges: The large number of PFAS compounds and their widespread use make it challenging for regulatory agencies to effectively manage and control PFAS exposure. Many PFAS compounds are still not well-studied or regulated.
In summary, the persistent, bioaccumulative, and toxic nature of PFAS, combined with their widespread use and exposure, make them a significant environmental and public health concern. Reducing PFAS use and exposure is an important goal for protecting human health and the environment.


“These chemicals are unique because of their ability to cause harm at such low levels,” said David Andrews, senior scientist at the Environmental Working Group, adding that the chemicals can prove to be a health concern at “parts per trillion” in drinking water. “They actually stick to our blood, and they tend to accumulate in our bodies.”

In recent years, a number of major companies, including McDonald’s and Burger King, have stated they’re planning to reduce or phase out the use of packaging with forever chemicals.

Skip microwave popcorn

Consumers can be frustrated because there’s no simple way to test products for PFAS, and the chemicals aren’t included on ingredient lists. Switching from packaged to fresh foods that don’t spend as much time on the shelf can reduce your risk of exposure.


“In general, food packaging is a source of contamination,” said Melanie Benesh, vice president of government affairs at the Environmental Working Group. “The fewer packaged foods that you are eating, the less likely you may be to be exposed.”

Some packaged foods are potentially exposed to PFAS in materials longer than others.

Some experts discourage frequent consumption of prepackaged microwave popcorn because the kernels are often sitting in that package of oil and other flavoring for an extended period of time.

Keith Vorst, an associate professor and the director of the Polymer and Food Protection Consortium at Iowa State University, said that when we heat up food in paper linings or plastic containers there’s a risk that some PFAS potentially coating the packaging can turn into a vapor and contaminate what we eat.

But, “we don’t know” what the risk of exposure is, Vorst said. “That is one area that we need to do some work in.”

It’s also not clear how much of our exposure to PFAS comes directly from the food supply. The FDA tested for 30 different types of PFAS in samples of 718 foods. It found 701 of the samples to be free of PFAS. Experts say the study was too limited in scope to draw broad conclusions because there are thousands of PFAS in use.

The testing of the food supply needs to be comprehensive, Andrews said.



Avoid nonstick cookware




Nonstick pots and pans are often coated in a material with PFAS. Peaslee said he has switched to ceramic cookware, and his eggs “are no worse than they used to be.”

“Be a little wary of things that are marketed as nonstick or stain-resistant or water-resistant,” Benesh said.


Cooking with stainless steel or cast-iron pans isn’t just about protecting yourself from these forever chemicals, DeWitt said. Your potential exposure from a nonstick pan may not be significant, but that doesn’t consider what it took to create the pan.

“The production of that pan is going to negatively impact other people who are bearing the brunt of the pollution that is produced when that nonstick coating is manufactured and applied,” DeWitt said.

Store leftovers in glass containers

Experts recommend storing leftovers and other food in glass containers, not plastic, in the fridge.

“Move away from plastics wherever possible,” Luppi said. “That’ll be one relatively easy and cost-effective thing to do.”

Drink filtered or bottled water

Check the results of water testing where you live and consider adding a water filtration system at home. Carbon filters on faucets or in water pitchers can reduce the levels of PFAS if the filters are replaced regularly, Andrews said. Reverse osmosis systems installed under sink faucets “can typically eliminate the PFAS contamination.”

The low-density plastic used for bottled water is not considered a potential source of PFAS contamination, Peaslee said. Unless a manufacturer makes a specific safety claim about PFAS, there’s no way for a consumer to know if the bottled water itself has been tested. “Bottled water is a lot safer than drinking a contaminated well with PFAS in it,” Peaslee said.


New tech could one day scrub ‘forever chemicals’ from your tap water

Check the source of the fish you eat

PFAS have been widely detected in freshwater fish. Last year, the FDA conducted a “targeted seafood survey” and detected PFAS in 74 percent of the seafood tested, including in clams, cod, crab, pollock, salmon, shrimp, tilapia, and tuna.

“Be cognizant of fish advisories,” DeWitt said. “Consume fish because it’s healthy for you. But, don’t eat fish for every meal every day.”

Do you have a question about healthy eating? Email EatingLab@washpost.com and we may answer your question in a future column.







How to avoid forever chemicals in food, drinking water - The Washington Post
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