Beating Cancer At Its Invasive Game
"As breast oncologists or cancer specialists we've spent the last decade trying to reduce the morbidity of what we do to patients -- in other words, trying to reduce the harm of what we do to patients, while achieving maximal cure."
"But at the same time, we're finding that, because of their fear and anxiety, patients are going the opposite way. They're demanding bigger things, bigger surgeries."
"It's not uncommon to hear women say, 'I don't care about my breasts. Or, I want to undergo chemotherapy'. And when your response is, 'you don't need to do that', what I often get back is, 'I have three kids, I want to know I did everything possible'."
"It's very hard to try to convince people that doing more is not helpful. In fact, it's harmful."
"I've definitely seen cases where it makes you wonder whether it was truly worth it."
Surgical oncologist Angel Arnaout, The Ottawa Hospital
"The fastest way to increase five-year survival rates, is to diagnose a whole lot of people with cancer."
"Today, we can find a lesion in a woman's breast the size of a green pea. And we can stick a needle into it and send a piece of that pea-sized lesion to a pathologist. And that pathologist says, 'this thing that you've sent me, this pea-sized lesion, looks just like what the Germans said killed that woman in 1850."
"It may be programmed [by nature] to stay pea-sized for the next 50 years in this 50-year-old woman's breast [or it may shrink and die because of a blood supply lack]."
"The real problem is the turtles, the cancers that aren't going anywhere. Unfortunately, screening is really good at finding turtles -- it's really good at finding the quiescent cancers that are just below the surface, the ones that are not obvious to people clinically [no symptoms], but if you look hard, all of a sudden you recognize they're there."
"If we could perfectly distinguish between all these things, there wouldn't be a problem. You'd recognize, that's a turtle and we're not going to do anything about it. But we can't, and that's why doctors tend to treat everything they find that's labelled 'cancer'."
"It's easy to find more cancers. The question is, who can find the cancers that matter?"
Dr. Gilbert Welch, American academic, cancer researcher, overdiagnosis expert
"Once in a while, these ['incidentalomas'] are serious conditions, and that's when everyone wins. But the knee-jerk position has been that if someone is found to have a small cancer, you better treat it before it gets worse."
"[Studies suggest a large proportion of kidney tumours are over-diagnosed, perhaps because they stop growing] or they grow too slow for the tumour to cause symptoms before the person dies of something else."
"We were diagnosing lots of patients with small amounts of cancer. So we said, let's just monitor; the ones who go up rapidly, we'll treat."
"People thought this was dangerous; that we didn't care if patients died. But we were absolutely convinced we were on the right track."
Dr. Laurence Klotz, urologic oncologist, Toronto
"I see what happens to people who end up on the wrong side of this, and behind each of these over-diagnoses is a story of a person who suffers because of it."
"My god, this is a precursor of cancer [when mammography detects DCIS], let's just get rid of them all and we're going to be preventing invasive cancer and curing it. Great idea. Except it didn't happen."
"People will blame you and say, 'What are you doing [for not treating DCIS as an emergency]? It's wrong, it's crazy'."
"If our treatments had no consequences, no negative side-effects, I wouldn't be pushing so hard for change. But people don't love what we offer for treatments."
Dr. Laura Esserman, breast surgeon, University of California, San Francisco
"There are some patients who, if left untreated, over time it eventually will turn into invasive cancer." "The problem is we also know that, 40 to 50 percent of patients with DCIS, that DCIS will never change if left untreated."
Dr. Geoff Porter, surgical oncologist, professor of surgery, Dalhousie University, Halifax
In the 1850s, Rudolph Virchow, a German pathologist, performed autopsies on women dead of invasive breast cancer, some of whose diseases were so advanced their breasts had been completely destroyed by the disease. A finding that led him to conclude that all cancers are deadly. Cancers that begin their existence as small tumours would inevitably grow inexorably to maturity, to spread throughout the body and destroy its host. That finding has resonance throughout the medical community and the public a century and a half later.
Technically advanced, sophisticated cancer-screening tools are capable of detecting indolent tumours through ultra-sounds, CT scans, MRIs, to discover "incidentalomas", propelled by complaints that are considered "non-specific", such as random pains here and there. In the process purely by chance lumps that seem suspicious that would under other circumstances never be discovered in the person's lifetime, are revealed. Although, to be fair, on occasion, serious conditions are found through this random search process.
Overdiagnosis of cancer ranges on a magnitude from 14 to 25 percent of breast cancers picked up by mamnography, to as much as 60 percent of prostate tumours detected by PSA screening, alongside 70 percent of thyroid cancers. There is no foolsafe manner of confidently setting aside what barely represents cancer, as opposed to a low-risk lesion from those that will grow and kill, so picking and choosing has consequences, unless a more assured method of discovering the truly dangerous cancers can be discovered.
To that end, medical researchers feverishly apply themselves to the discovery of biological and molecular markers, genomic signatures that will give assurance that what has been isolated truly is a cancer whose presence should be feared and targeted. The expedient currently informing medical specialists is to generally prescribe chemotherapy and radiation. Both of which, applied to the chest area, have the potential to damage the heart or lungs, or to cause long-term brain side effects, or affect the spinal cord or nerves.
An estimated 20 to 30 percent of women undergoing mastectomy experience post-surgical pain syndrome; nerve pain that lingers, causing burning, tingling and stabbing pain at the site of the surgery. Many women are informed at diagnosis that they have ductal carcinoma in situ (DCIS); tiny flecks of calcium deposits detected through breast screening programs. Under a microscope, cells that comprise DCIS appear as early cancer and doctors made the assumption that these "precursors" to cancer aggressively excised would reduce invasive, lethal breast tumour numbers.
Today DCIS accounts for almost one-quarter of all breast cancers, yet their removal through bilateral mastectomies [both breasts removed; the 'affected' one, and by choice, its sister], has not led to a diminution of the invasive cancers. Leading researchers to the feeling that many women diagnosed with DCIS may unnecessarily be undergoing aggressive treatments leading to minimal or no benefit whatsoever. Simply put, some cancers should simply be left alone; and some 'cancers' may not in fact be cancers.
The abnormal DCIS cells are confined to the milk duct lining; without penetration of that basement membrane, the chance of cancer spreading is remote. And then there is the issue of distinguishing the appropriate response, as for example, research headed by Dr. Steven Narod of Toronto's Women's College Hospital suggesting that younger women diagnosed before age 35, and black women are at higher risk than their opposite counterparts; older, white women.
Dr. Esserman offers women with low-grade DCIS hormone therapy or monitoring with ultrasounds as an option, after determining through genomic tests whether the DCIS will grow or recede.
As for prostate cancer, thanks to the work of Dr. Klotz who has revolutionized treatment for men with low-risk prostate cancer, active surveillance has become the cornerstone of its treatment in cancer clinics around the world. Even so, it is a more cautious remedy that has not yet become standard; an estimated 1,500 men with low-risk prostate cancer in Canada received treatment, many of whom could have been spared it, along with the side-effects like impotence and urinary incontinence.
While no one undertakes treatments with the intention of causing harm to patients, DCIS should not be treated as an emergency, states Dr. Esserman. Women should be given details of all relevant information concerning their diagnoses, and allowed the time and the opportunity to consider options.
As for Dr. Arnaout, she schedules multiple visits with her patients, and other than high-risk cases does not offer to remove a disease-free breast until at least a year has passed and the situation requires such a solution.
Labels: Bioscience, Cancer, Disease, Health, Research
0 Comments:
Post a Comment
<< Home