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She Wiped Her Nose, Then Prepped My Biopsy. Still, It's Hard To Ask The Nurse To Wash Her Hands

Hand washing before and after touching a patient is mandatory. And before and after walking into a patient’s room or touching medical equipment. (Arlington County/Flickr)

Hand washing before and after touching a patient is mandatory. And before and after walking into a patient’s room or touching medical equipment. (Arlington County/Flickr)

I was lying on my back on a gurney, getting my abdomen washed by the nurse.

She dipped Q-tip-like sticks into the brown antiseptic and then swirled them on my skin where the physician would make his incision. He would penetrate layers of skin and muscle to get into my liver and extract cells. He would send the cells to the laboratory to assess what kind of cancer I had. Eight days earlier, I had learned I had masses in my abdomen and chest. Three days earlier, I had learned the masses were cancer. That day I was on the gurney getting prepped for a liver biopsy, to find out what kind of cancer it was.

While one nurse washed my incision site, another nurse prepared the room. She was adjusting the lights, surgical equipment and my gown. And she rubbed her nose with her hand. Everyone rubs their nose. Humans unconsciously touch their nose or mouth more than 3.6 times per hour.

When we do this, we spread germs into our body from whatever we were touching before and spread germs from our body onto whatever we touch next.

I laid there and wondered if I should say something to her.

In medical school in the early ’90s, I had learned about the risk of normal nose bacteria infecting surgical sites. While on the gurney that day, I remembered a story about a patient with a massive infection in his surgical wound site. The hospital searched for the source of his Staph aureus. They found it in the surgeon’s nose. This story was told to us to remind us of the dangers of what we were seeing on the wards in medical school — which was still full of old-school clinicians who drew blood without gloves and washed their hands only intermittently.

Today things are supposed to be different. Hand washing before and after touching a patient is mandatory. And before and after walking into a patient’s room or touching medical equipment. The compulsory annual online classes for all clinicians include specific directions on how to wash your hands. There are signs on the walls and screen savers on the hospital computers reminding us to wash our hands.

But there I was, flat on my back, wondering if I should say something to the nurse. I was afraid she’d be upset with me if I said something — I was all but naked, lying on my back and pretty much in her hands. The hands that had just wiped her nose. I didn’t say anything. I tried to get my courage up to say something — but couldn’t. A few minutes passed. I decided it was too late to say anything. But I told myself if she did it again, I would say something to her.

And then she did. She rubbed her nose with her hand and then reached for the equipment table with that same hand. The equipment that would be in my liver in a few minutes.

I called her on it. Continue reading

Unequal Cancer: Leukemia Study Finds Children In Poverty Face Earlier Relapse

How might poverty impact childhood cancer?

That’s the question pediatric oncologist Dr. Kira Bona, a researcher at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, set out to answer.

Her findings: Even with the same medical treatment, children with leukemia living in high-poverty areas were more likely to suffer an early relapse compared to their wealthier counterparts. The research, published this week in the journal Pediatric Blood & Cancer, is important, Bona says, because earlier relapses of this particular cancer — the most common pediatric cancer, called acute lymphoblastic leukemia — are harder to treat successfully.

We already know poverty is bad for your overall health. Among children, Bona says, poor kids tend to have worse underlying health, and higher rates of hospitalization, infectious disease and risk of death compared to more affluent children.

(DebMomOf3/Flickr)

(DebMomOf3/Flickr)

When it comes to cancer treatment though, for the 15,000 American children diagnosed with cancer every year, most are enrolled in clinical trials and treated using similar protocols, Bona said. Still, she said: “Historically, in pediatric oncology, we haven’t included social determinants of health, like poverty and education, as part of the data we collect in clinical trials; we’ve had an almost exclusive focus on biology.”

But since about 20 percent of kids in the U.S. live in poverty, Bona says, that non-biological data is also critical.

I spoke with Bona more about the latest research. Here, edited, is some of our discussion:

What’s the bottom-line finding here?

We looked at 10 years of data; 575 kids ages 1-18 who were treated at major academic medical centers around the U.S, with uniform therapy as part of the same two consecutive clinical trials. We went back and analyzed disease outcome data — overall survival and relapse data — with the question: Does poverty impact these disease outcomes? We used a proxy for poverty, zip codes linked to U.S. census data, to determine high-poverty or low-poverty areas.

We did not see a significant difference in overall survival between high-poverty and low-poverty groups. Additionally, we did not find a significant difference in relapse rates. But we did see a significant difference in the timing of relapse. And the timing of relapse is important, because if you experience an early relapse it’s harder for us to ultimately cure you. Continue reading

Opinion: What A Cancer Cure ‘Moon Shot’ Might Look Like

During his final State of the Union address, President Obama announced a new national effort to cure cancer. He said Vice President Joe Biden, who lost his 46-year-old son to cancer last year, would lead the effort. (Evan Vucci/AP)

During his final State of the Union address, President Obama announced a new national effort to cure cancer. He said Vice President Joe Biden, who lost his 46-year-old son to cancer last year, would lead the initiative. (Evan Vucci/AP)

In his final State of the Union address Tuesday night, President Obama called for a historic new effort to find a cure for cancer, a “moon shot.”  

“For the loved ones we’ve all lost, for the family we can still save, let’s make America the country that cures cancer once and for all,” Obama said in naming Vice President Joe Biden to lead the effort. 

So what might such a massive endeavor look like? Here, Barrett Rollins, M.D., Ph.D., chief scientific officer at the Dana-Farber Cancer Institute, offers his vision:

President Obama’s call for a new national effort against cancer — a “moon shot” — comes at a most opportune time. Cancer research has advanced significantly and now genomic analysis of tumors can reveal the specific DNA changes that drive cancer growth.

Our patients at Dana-Farber/Brigham and Women’s Cancer Center and Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, through the Profile research project, are benefiting from this — using the powerful technique of next-generation sequencing, scanning more than 300 cancer-related genes in every patient’s tumor to look for abnormalities. In a growing number of cases, the DNA changes can be targeted by precision therapies such as designer drugs that block overactive growth pathways. Often it will take combinations of targeted drugs to halt cancer progression, and many studies of these combinations are underway.

At the same time, there’s enormous promise in the field of immunotherapy. We’ve learned how to boost the body’s natural defenses against cancer and how to remove the molecular “brakes” that cancer cells exploit to hide from immune soldier cells and hinder their attack on tumors. Drugs that help the immune system fight cancer are coming quickly to the market, and there is promising research on related strategies such as cancer vaccines and genetic manipulation of immune cells to recognize cancer cells in the body. Continue reading

From Cancer Drugs To Gut Bugs: 10 Medical Trends To Watch In 2016

Former President Jimmy Carter, whose latest brain scans show no sign of the melanoma he was diagnosed with, is a high-profile example of recent advances in treating cancer. (David Goldman/AP)

Former President Jimmy Carter, whose latest brain scans show no sign of the melanoma he was diagnosed with, is a high-profile example of recent advances in treating cancer. (David Goldman/AP) 

By Dr. Michael Misialek
Guest contributor

2016 is the year of the monkey, according to the Chinese calendar, but from my corner of the medical world — as a pathologist who tries to stay current on the medical big picture — it’s looking more like the year of the crab (cancer, that is).

Looking through my microscope, I expect the most striking medical advances next year in the field of cancer treatment. More broadly, here’s what I expect in the year to come, starting with scientific and technological progress and then getting into the health care system.

1. Cancer: Immunotherapy And More

Immunotherapy for cancer exploded in 2015. What is immunotherapy? It’s the technique by which the power of the immune system is harnessed to attack cancer. It’s already used in many cancer treatments, but it tends to be a second-line approach or reserved for advanced disease. In 2016, we’ll see more immunotherapy treatments approved and they will likely become the first-line choice in many cancers.

We can also expect to see more cell-mediated therapies — engineering a patient’s own immune cells to attack cancer — added to the cancer armamentarium. And expect to hear more about epigenetics — using the cancer cell’s genetic programming to push it back toward normalcy.

Recently, the American Association for Cancer Research convened an international immunotherapy conference, which completely sold out. One of the biggest stories to emerge was how chemotherapy resistance can be overcome using engineered proteins. Resistance is an all-too-common problem that dampens the hopes of precision medicine. These proteins, which are smaller than antibodies, will bring immunotherapy to new levels in 2016.

New drug combinations, combining traditional chemotherapy with immunotherapy, will also blossom in 2016. Such approaches are already showing promise in lung cancer, prostate cancer and melanoma. And we can expect new vaccines against cancer to emerge in 2016.

2. Related: ‘Basket Studies,’ A New Approach to Clinical Trials

Traditional drug trials test a drug against a known cancer type. With the precision medicine revolution upon us, it has become evident that many cancers, regardless of type, often share the same genetic mutations. 2015 saw the first trials of using a drug in an off-label manner to target common mutations across cancers of many different organs. Such “basket trials,” I think, will explode in popularity in 2016 in an effort to bring greater patient access to drugs. This new clinical trial paradigm will become commonplace in 2016. Already the American Society of Clinical Oncology is sponsoring its first-ever basket trial, partnering with five drug companies. Expect preliminary results in 2016.

3. Leveraging Our Gut Microbes

A microbiologist points out an isolated E. coli growth on an agar plate. E. coli is a gut microbe that plays a major role in health and disease. (Elaine Thompson/AP)

A microbiologist points out an isolated E. coli growth on an agar plate. E. coli is a gut microbe that plays a major role in health and disease. (Elaine Thompson/AP)

The bacteria in the gut have long been known to play a role in the immune system and metabolism. Now, new research is showing that many diseases may be caused in part by gut microbes, and I expect the coming year to bring a flurry of new uses for these microbes.

One of the fasting-growing applications is the use of fecal transplants to treat the deadly Clostridium difficile infection. Other diseases such as inflammatory bowel disease, irritable bowel syndrome, autoimmune diseases and allergic disease will likely see bacteria-based treatment advances in 2016.

Recently, gut microbes have even been shown to reduce the side effects of chemotherapy. Perhaps most exciting are the ways in which these bacteria are detected. Traditional methods of bacterial culture will become replaced by genetic sequencing of bacterial DNA. Such powerful information is already showing early promise in helping to stem transmission of drug-resistant bacteria within and between hospitals, a major cause of illness and death.

Continue reading

Related:

Jimmy Carter’s Good News And The Ever-Brightening Outlook For Melanoma

Former President Jimmy Carter teaches Sunday School class at Maranatha Baptist Church on Aug. 23 in Plains, Georgia, soon after he announced he was bring treated for cancer. (David Goldman/AP)

Former President Jimmy Carter teaches Sunday School class at Maranatha Baptist Church on Aug. 23 in Plains, Georgia, soon after he announced he was bring treated for cancer. (David Goldman/AP)

In August, former President Jimmy Carter announced that he was being treated for melanoma, a skin cancer that had spread to his liver and brain. Now, Carter says that his latest brain scan shows no sign of cancer spots.

This is not necessarily a “cure,” but it’s hard to imagine a more striking illustration of recent progress on treating malignant melanoma, once considered an imminent death sentence.

We sought some perspective from Dr. Elizabeth Buchbinder, a melanoma specialist at the Dana-Farber Cancer Institute.

Jimmy Carter says there’s no cancer showing up on his MRI. What does that mean?

EB: It’s incredibly exciting. It basically means that the lesions that were seen there before have resolved or disappeared or whatever term you’d like to use. And so it’s a great response. It’s what we would call a complete response on imaging, which is really really excellent, obviously.

The issue becomes this: We have limits to what our imaging can see. So we never know that there’s no cancer anywhere. But we know that there is none we can detect, which is very exciting. So all the cancer that we could see previously is now no longer detectable.

What does that mean happened biologically?

Biologically, he had a couple things happen, because he got radiation, which damaged his cancer, and he got [the drug] Keytruda. And what the Keytruda did is it turned on the immune system to act against those tumors. So the immune system then attacks and basically gets rid of cancer cells. And so very likely his immune system got turned on, attacked those cancer cells, eradicated what was there, and hopefully is continuing to eradicate anything we can’t see, and it now recognizes the cancer as something that it needs to get rid of.

When you have a great response like this, is it likely to remain so great?

“We’re really seeing a lot of people who are living a long, long time with either minimally detectable or no detectable cancer.”

– Dr. Elizabeth Buchbinder

Very likely. With immune therapy in particular, and even going back to some of the earliest immune therapies that we have used, such as an older one called Interleukin 2 — when it’s used, if you have a complete response and no longer have any detectable cancer, the chances of that continuing are much much higher than if you just see a little bit of shrinkage, or some degree of shrinkage but can still detect cancer. So chances are very, very good that Jimmy Carter will continue to do well going forward and not have trouble with cancer in the future. We can never say 100 percent, but this is definitely a very good response.

I imagine you now need to throw a bit of cold water on all the people who will call and say ‘I want what he got.’ What would you say to those patients? Continue reading

Related:

Study: Risk Of Hidden Cancer In Gynecologic Surgery Higher Than Previously Thought

Undetected cancer among women undergoing a type of minimally invasive hysterectomy or fibroid removal surgery is more common than previously thought, a new study finds. Researchers at Boston Medical Center report that the risk of such hidden cancer is about 1 in 352 women.

The upshot: these women may have had the undetected cancer spread within their bodies inadvertently through a technique that has fallen out of favor called “power morcellation,” which was typically used in these types of surgeries. The technique involves cutting the woman’s uterus or fibroids into small pieces to make them easier to remove during the less invasive laparoscopic procedure.

The new findings (which looked at the cases of more than 19,000 women) support a 2014 estimate by the U.S. Food and Drug Administration that approximately 1 in 350 women undergoing this type of surgery face the risk of hidden cancer. But earlier conventional wisdom was that the risk of undetected cancer for women undergoing this kind of surgery was closer to 1 in nearly 5,000 or more.

“The take-home message of the study is that the true risk of an undetected cancer at the time of gynecologic surgery for what was assumed to be benign disease is about 1 in 352 women,” says Dr. Rebecca Perkins, a practicing gynecologist at BMC and lead author of the new study.

This kind of minimally invasive surgery had “increased greatly” over the past decade, researchers report, because the procedures involved less pain and shorter recoveries, among other benefits.

But power morcellation came under public and regulatory scrutiny a few years ago (in large part due to excellent reporting by Jennifer Levitz at The Wall Street Journal). In 2014, the FDA issued a series of warnings against the use of laparoscopic power morcellators in the majority of women undergoing these types of gynecologic surgeries because of the risk of spreading unsuspected cancer.

At that time, regulators estimated the risk of hidden cancer this way:

Based on an FDA analysis of currently available data, we estimate that approximately 1 in 350 women undergoing hysterectomy or myomectomy for the treatment of fibroids is found to have an unsuspected uterine sarcoma, a type of uterine cancer that includes leiomyosarcoma. At this time, there is no reliable method for predicting or testing whether a woman with fibroids may have a uterine sarcoma.

If laparoscopic power morcellation is performed in women with unsuspected uterine sarcoma, there is a risk that the procedure will spread the cancerous tissue within the abdomen and pelvis, significantly worsening the patient’s long-term survival. While the specific estimate of this risk may not be known with certainty, the FDA believes that the risk is higher than previously understood.

Continue reading

Mass. Cancer Snapshot: Deaths Dropping, Racial Gaps Narrow, But Not All Good News

A woman is screened for breast cancer in Los Angeles in 2010. (Damian Dovarganes/AP/File)

A woman is screened for breast cancer in Los Angeles in 2010. (Damian Dovarganes/AP/File)

Dear readers: CommonHealth is pleased to host a special M.D.-PhD guest writer, David Scales, for the next four weeks. His first assignment: What strikes you most about the latest state numbers on cancer?

Those numbers are just out from the Massachusetts Cancer Registry — the state Department of Public Health plans to post them here within the next couple of days. The good news is that overall, the death rate from cancer in Massachusetts has been dropping. But not all the news is good. Please read on.

By David Scales

As a resident in general internal medicine, I’m not a cancer expert. But my biggest takeaway from these latest state cancer numbers is positive: that we’re becoming better at detecting cancers and getting better at treating them.

We have a long way to go to extend these advances broadly to groups that are less likely to get screened for cancers, including African-Americans, Hispanics and people with low access to health care, but it’s encouraging to see that the trends are generally going in the right direction.

So what should you take away from the new numbers? My top five points:

• Good news and bad news

Bad news first: Cancer diagnosis rates — the number of people diagnosed with cancer for every 100,000 people — are higher in Massachusetts than nationwide.

OK, now the good news: Mortality rates from cancer are generally lower here than national rates. That may sound confusing, but it means people living in Massachusetts are more likely to be diagnosed with cancer but less likely to die from it than people in the rest of the country.

The reasons for this aren’t clear, but Massachusetts has some of the best hospitals in the world. It’s possible we are better both at detecting cancers and at treating them.

• More reason to get that colonoscopy

The report has great news for the prevention of colorectal cancer, the third most common cancer in both men and women in Massachusetts.

Men have seen a huge drop in colorectal cancer diagnoses, from a rate of 68.4 to 39.1 per 100,000 people, meaning that fewer and fewer men are being diagnosed with the disease.

There’s been a large drop in women as well, from 48.2 to 32.0 per 100,000. It’s not yet clear what caused this drop, but the Massachusetts Department of Public Health speculates that it may be due to colonoscopies. During a colonoscopy, the doctor takes out growths in the colon called polyps, some of which may be pre-cancerous. If polyps are removed before they cause cancer, then that would explain why fewer people are getting diagnosed with the disease. Overall, this is good news — it suggests that colorectal cancer screening is working.

• Don’t smoke, don’t smoke, don’t smoke

There are few certainties in life and even fewer in medicine. But one thing is clear: Don’t smoke.

The leading cause of cancer-related deaths in Massachusetts is lung cancer. And while the number of people dying from lung cancer has decreased, that decrease is almost certainly due to reduced rates of smoking. Men smoke more than women, though, so they continue to be more likely to get lung cancer and are more likely to die from it than women.

• Blacks and whites and prostate cancer  Continue reading

WHO Says Processed Meat Causes Cancer, So Should We Stop Eating It Altogether?

Is this the end of bacon, hot dogs and corned beef on rye? (Didriks/Flickr)

Is this the end of bacon, hot dogs and corned beef on rye? (Didriks/Flickr)

Is this the end of bacon, hot dogs and corned beef on rye?

How should consumers react to news from the World Health Organization that these and other processed meats can cause cancer, and that red meat, including beef, pork, veal and lamb, are “probably carcinogenic to humans” too? Should we abstain completely now that the WHO’s International Agency for Research on Cancer (IARC) put processed meat in the same cancer-risk category as tobacco and asbestos?

Here’s the bottom line risk, from the IARC news release: “The experts concluded that each 50 gram portion of processed meat eaten daily increases the risk of colorectal cancer by 18%.”

Processed meats have previously been inked to a range of illnesses, from heart disease to diabetes and cancer. But even with this big news from the WHO, many nutrition and public health experts said that reducing consumption of such meats is key, not eliminating them altogether.

Frank Hu, a professor of nutrition and epidemiology at the Harvard School of Public Health, says there’s no need for everyone to suddenly become vegetarian or vegan. But, he said in an interview, he hopes the WHO announcement will spark real dietary change.

He made three points:

1. The WHO Announcement Is Big 

“I think the WHO announcement is very significant from a public health point of view because processed red meats have already been linked to type 2 diabetes, cardiovascular disease and other chronic disease, and this provides convincing evidence that consuming processed meats, like bacon, sausage, hot dogs, is linked to an increased risk of colorectal cancer in particular. Cutting back on red meat and processed meat reduces risk of diabetes and cardiovascular disease, but also reduces the risk of cancer. Improving your diet can actually be beneficial for reducing your cancer risk.”

2. You Don’t Need To Quit

“I’m not a vegetarian. This doesn’t mean everyone should become a vegetarian or vegan. Processed red meat should be consumed as little as possible — once or twice a week should not be a major problem. For unprocessed red meat, consumption should be moderate, but that’s hard to quantify; maybe every other day. We’re not talking about banning hot dogs, sausages or bacon, but we should change our dietary pattern from a meat-based diet to a more plant-based diet. That’s not really a new message. This message will hopefully raise more awareness. Hopefully it will motivate people to change their eating patterns.”

3. Change The Food Environment

“Certainly the risk accumulates as the amount increases, and if you can stay away from it completely that would be good. But occasional consumption of processed red meat isn’t going to create significant health problems … There are so many chemicals and ingredients in processed red meats — preservatives, nitrates, high sodium, saturated fats — it’s difficult to pinpoint exactly which chemicals cause cancer. From a public health point of view, it’s not necessary to know which chemicals are precisely responsible for the increased risk. Here the message is similar to tobacco, even though we may not know precisely which chemical cause the cancer, we can take actions to reduce the cancer risk by cutting back … It’s also important for the government to improve the food environment. There’s so much junk food in the food system.” Continue reading

Cancer Drug Mark-Ups: Year Of Gleevec Costs $159 To Make But Sells For $106K

A new study finds that a year's supply of Gleevec (imatinib), a leukemia drug, costs about $159 to make, but the yearly price tag is $106,322 in the U.S. and $31,867 in the U.K. (Wikimedia Commons)

A new study finds that a year’s supply of Gleevec (imatinib), a leukemia drug, costs about $159 to make, but the yearly price tag is $106,322 in the U.S. and $31,867 in the U.K. (Wikimedia Commons)

By Richard Knox

The rocketing cost of prescription drugs garners almost daily attention lately. Polls say it’s high on the list of Americans’ health care worries; presidential candidates are calling for sweeping reform; a storm erupts when one company jacks up the price of an HIV drug by 5,000 percent.

And now, research reveals the yawning gap between the price of widely used cancer drugs and their actual cost.

The true cost — what drug makers have to spend to get those pills to your local pharmacy — is made up of the active ingredient and other chemicals, their formulation into a pill, packaging, shipping and a profit margin.

British researchers, in a report to be delivered this weekend at a European cancer conference, say the price of five common cancer drugs is more than 600 times higher than they cost to make.

For instance, the analysis figures the true cost of a year’s supply of Gleevec (generic name imatinib), used to treat certain kinds of leukemia, at $159.

“This is a ginned-up pricing structure that isn’t a product of careful analysis. It’s not a bunch of guys in green eye-shades but a bit of dart-throwing and chutzpah.”

– Dr. Peter B. Bach

But the yearly price tag for Gleevec is $106,322 in the U.S. and $31,867 in the U.K. A generic version costs about $8,000 in Brazil.

“We were quite surprised just how cheap a lot of these cancer drugs really are,” pharmacologist Andrew Hill of the University of Liverpool said in an interview. “There’s a lot of scope for prices to come down.”

Hill’s team got the ingredient costs from a public data base called IndiaInfoDrive.com. The Liverpool group did the same analysis for four other drugs in the same class, called tyrosine kinase inhibitors, or TKIs. They’re used to treat lung, breast, liver, pancreas and thyroid cancer as well as leukemias. Their names are Tarceva (erlotinib), Nexavar (sorafenib), Tykerb (lapatinib) and Sprycel (dasatinib).

The true yearly cost of these four drugs ranges from $236 for Tarceva to $4,022 for Tykerb. But their U.S. sticker prices range from $78,797 to $135,679.

The analysis has implications beyond the United States. Hill says more than a million cancer patients around the world meet criteria for taking the five TKI pills. “Very few of them are being treated now,” he says, because the drugs are so expensive.

A 100-Fold Rise

And the implications stretch way beyond these specific cancer drugs. Overall prices for cancer medications have been going up at a fast clip. Dr. Peter B. Bach of Memorial Sloan Kettering Cancer Center in New York has documented a nearly 100-fold increase in cancer drug prices since 1965 after adjusting for inflation.

“The rate of rise exceeds the rise in benefits from these drugs,” Bach says. “This is a ginned-up pricing structure that isn’t a product of careful analysis. It’s not a bunch of guys in green eye-shades but a bit of dart-throwing and chutzpah. And if there’s a critical Op Ed piece or a Twitter avalanche [in response to a high price] they’ll lower it.” Continue reading

Bugs And Kids: Indoor Insecticide Use Linked To Childhood Cancers, Study Finds

(Tom Simpson/Flickr)

(Tom Simpson/Flickr)

I just threw out my spray can of Raid for flying insects. With kids in the house, I never did like the idea of spewing toxic stuff around, and only ever used it when a bug was driving me to feral insanity. Now, after reading the paper just out in this week’s issue of the journal Pediatrics, I’ll stick with the flypaper and swatter no matter how intense my irritation.

The paper concludes that the sum of previous research suggests a significant link between indoor pesticide use and childhood cancer.

To be more exact, senior author Chensheng Lu says the results “suggest that when kids are exposed to pesticides — especially a group of pesticides we call insecticides — in the indoor residential environment, kids have 43 to 47 percent more chance of having childhood cancers, specifically leukemia and lymphoma.”

Dr. Lu is an associate professor of environmental exposure biology at the Harvard T.H. Chan School of Public Health. He acknowledges the study’s limitations, in particular that it could find only 16 relevant previous papers to analyze. But, he says, it showed “consistent results in terms of the positive correlation between exposure to insecticide indoors and childhood cancer.”

The study does not aim to “cause fear in parents,” Lu says. “But it’s to give you a precautionary principle that those exposures can be prevented, can be mitigated or can be completely removed.”

Of course, these findings only heighten the dilemma for households or schools that are tormented by pests, with infestations too fierce to be dented by anything but the big toxic guns. Are we supposed to just let the roaches and mosquitoes run wild?

Dr. Lu points out that preventive measures like window screens and hole-plugging can help, and among pesticides, some applications are safer than others — for example, “bait houses” that try to attract the pest inside a box-like structure to be poisoned.

“The worst-case scenario in terms of indoor pesticide use and human exposure it to use some kind of fogger,” he says. “Also, some kind of open-air application, a broadcast application, a spray can. Those are bound to significant exposures.” Continue reading